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  Subjects -> VETERINARY SCIENCE (Total: 207 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 1)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 2)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 1)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 14)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 2)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 10)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 22)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 141)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Nutrition     Open Access   (Followers: 13)
Animal Reproduction     Open Access   (Followers: 1)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 7)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 6)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 2)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access  
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 3)
Australian Veterinary Journal     Hybrid Journal   (Followers: 19)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 6)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access   (Followers: 1)
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 2)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 12)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 8)
Buletin Peternakan : Bulletin of Animal Science     Open Access  
Buletin Veteriner Udayana     Open Access   (Followers: 2)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 9)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 6)
Equine Health     Full-text available via subscription   (Followers: 3)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 15)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 2)
FAVE Sección Ciencias Veterinarias     Open Access  
Folia Veterinaria     Open Access  
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal   (Followers: 1)
In Practice     Full-text available via subscription   (Followers: 2)
Indian Journal of Animal Sciences     Open Access   (Followers: 7)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 4)
Indonesia Medicus Veterinus     Open Access   (Followers: 1)
Intas Polivet     Full-text available via subscription   (Followers: 2)
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Irish Veterinary Journal     Open Access   (Followers: 6)
Japanese Journal of Veterinary Research     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 8)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 2)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 5)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 11)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Feline Medicine and Surgery Open Reports     Open Access   (Followers: 1)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 4)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 13)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 36)
Journal of the Selva Andina Research Society     Open Access   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Dentistry     Full-text available via subscription  
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 8)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 17)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 23)
Journal of Veterinary Medical Education     Partially Free   (Followers: 13)
Journal of Veterinary Medicine     Open Access   (Followers: 10)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 5)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 8)
Journal of Veterinary Research     Open Access   (Followers: 1)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 4)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 6)
Jurnal Agripet     Open Access  
Jurnal Medika Veterinaria     Open Access  
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription   (Followers: 2)
Macedonian Veterinary Review     Open Access   (Followers: 2)
Media Peternakan - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 5)
Medical Mycology Case Reports     Open Access   (Followers: 1)
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 12)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 4)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 1)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 4)
Open Access Animal Physiology     Open Access   (Followers: 4)
Open Journal of Animal Sciences     Open Access   (Followers: 5)
Open Journal of Veterinary Medicine     Open Access   (Followers: 4)
Pesquisa Veterinária Brasileira     Open Access  
pferde spiegel     Hybrid Journal  
Polish Journal of Veterinary Sciences     Open Access   (Followers: 3)
Pratique Médicale et Chirurgicale de l'Animal de Compagnie     Full-text available via subscription  
Preventive Veterinary Medicine     Hybrid Journal   (Followers: 11)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research & Reviews : Journal of Veterinary Science and Technology     Full-text available via subscription   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 10)
Research Journal of Veterinary Sciences     Open Access   (Followers: 10)
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access  
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Reprodução Animal     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
Revista Ciencia Animal     Open Access  
Revista Ciencias Veterinarias     Open Access  
Revista Científica     Open Access  
Revista Colombiana de Ciencias Pecuarias (Colombian journal of animal science and veterinary medicine)     Open Access   (Followers: 1)
Revista Complutense de Ciencias Veterinarias     Open Access  
Revista da Sociedade Brasileira de Ciência em Animais de Laboratório     Open Access  
Revista de Ciência Veterinária e Saúde Pública     Open Access  
Revista de Ciências Agroveterinárias     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Investigaciones Veterinarias del Perú     Open Access  
Revista de Medicina Veterinaria     Open Access  
Revista de Salud Animal     Open Access  
Revista Mexicana de Ciencias Pecuarias     Open Access  
Revista MVZ Córdoba     Open Access  
Revista Veterinaria     Open Access  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
Revue Vétérinaire Clinique     Full-text available via subscription  
SA Stud Breeder / SA Stoetteler     Full-text available via subscription  
Schweizer Archiv für Tierheilkunde     Hybrid Journal  
Scientific Journal of Animal Science     Open Access   (Followers: 4)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 1)
South African Journal of Wildlife Research     Open Access   (Followers: 1)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 1)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 3)
Theriogenology     Hybrid Journal   (Followers: 1)
Tierärztliche Praxis Großtiere     Hybrid Journal  
Tierärztliche Praxis Kleintiere     Hybrid Journal  
Topics in Companion Animal Medicine     Hybrid Journal   (Followers: 3)
Transboundary and Emerging Diseases     Hybrid Journal   (Followers: 3)
Trends in Animal and Veterinary Sciences     Open Access   (Followers: 6)
Trends in Parasitology     Full-text available via subscription   (Followers: 8)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinária e Zootecnia     Open Access  
Veterinária em Foco     Open Access  
Veterinaria México     Open Access  
Veterinária Notícias     Open Access  
Veterinary Anaesthesia and Analgesia     Hybrid Journal   (Followers: 11)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 8)
Veterinary and Comparative Orthopaedics and Traumatology (VCOT)     Hybrid Journal   (Followers: 3)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 9)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 9)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 7)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 5)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 18)
Veterinary Dermatology     Hybrid Journal   (Followers: 7)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 10)
Veterinary Journal     Hybrid Journal   (Followers: 18)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 4)
Veterinary Medicine and Science     Open Access   (Followers: 1)
Veterinary Medicine International     Open Access   (Followers: 8)
Veterinary Medicine: Research and Reports     Open Access   (Followers: 4)
Veterinary Microbiology     Hybrid Journal   (Followers: 10)
Veterinary Nurse     Full-text available via subscription   (Followers: 5)
Veterinary Nursing Journal     Hybrid Journal   (Followers: 4)
Veterinary Ophthalmology     Hybrid Journal   (Followers: 6)
Veterinary Parasitology     Hybrid Journal   (Followers: 8)
Veterinary Parasitology : Regional Studies and Reports     Full-text available via subscription  
Veterinary Pathology     Hybrid Journal   (Followers: 13)
Veterinary Quarterly     Hybrid Journal   (Followers: 3)
Veterinary Radiology & Ultrasound     Hybrid Journal   (Followers: 12)
Veterinary Record     Full-text available via subscription   (Followers: 18)
Veterinary Record Case Reports     Full-text available via subscription   (Followers: 2)
Veterinary Record Open     Open Access   (Followers: 3)

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Journal Cover Domestic Animal Endocrinology
  [SJR: 0.751]   [H-I: 59]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0739-7240
   Published by Elsevier Homepage  [3031 journals]
  • A sandwich ELISA for porcine alpha-1acid glycoprotein (pAGP, ORM-1) and
           further demonstration of its use to evaluate growth potential in newborn
           pigs
    • Abstract: Publication date: Available online 8 April 2017
      Source:Domestic Animal Endocrinology
      Author(s): T.J. Caperna, A.E. Shannon, M. Stoll, S. Kahl, L.A. Blomberg, J.L. Vallet, T.G. Ramsay
      A simple,-reproducible sandwich ELISA was developed to measure porcine alpha-1 acid glycoprotein (pAGP, ORM-1) in pig plasma. Porcine AGP isolated from serum was purchased and a polyclonal antisera was prepared in rabbits using the whole pAGP molecule as immunogen. The antiserum was affinity-purified and a portion of the purified antibody fraction was labeled with horseradish peroxidase. Porcine AGP protein was used as a standard while commercially available buffers and reagents were utilized throughout the assay. The assay was specific for pAGP, had a lower limit of detection of 3.2 ng/mL and could be used to quantify pAGP in plasma or serum. Using this ELISA, we corroborated our previous findings obtained by RID assay, which demonstrated that the AGP concentration in newborn piglets is negatively associated with preweaning growth rate. The current data were obtained using piglets from a different geographical location and genetic background and showed that elevated AGP at birth was associated with reduced preweaning growth rate (P < 0.001, r = 0.433, n = 19 litters). In addition, litters with a greater average AGP at birth were at a growth disadvantage compared to litters with reduced average AGP plasma concentrations (P < 0.001, r = 0.708, n = 19 litters). Litter average plasma AGP was a better predictor of litter preweaning growth rate than average litter birth weight. The data represent further support for using perinatal AGP concentrations as a tool to identify potential slower growing pigs and as a plasma biomarker for predicting litter growth rate.

      PubDate: 2017-04-14T03:03:09Z
       
  • Evaluation of a commercially available radioimmunoassay and enzyme
           immunoassay for the analysis of progesterone and estradiol and the
           comparison of two extraction efficiency methods
    • Abstract: Publication date: Available online 5 April 2017
      Source:Domestic Animal Endocrinology
      Author(s): C.S. Skenandore, A. Pineda, J.M. Bahr, A.E. Newell-Fugate, F.C. Cardoso
      The measurement of progesterone (P4) and estradiol (E2) is essential for monitoring reproductive cycles and can aid in diagnosing the cause of poor reproductive performance in dairy cattle. Readily available, reproducible, accurate, non-radioactive assays are needed for the assessment of P4 and E2 in bovine serum. The gold standard for hormone assessment, radioimmunoassay (RIA), was compared with enzyme-linked immunoassay (EIA). Serum collected from various points in the estrous cycle was extracted with radiolabeled P4 (i.e.: 3H-P4; HE) and without 3H-P4 (CE) prior to being utilized in the assay. For the assessment of P4, there is a great degree of correlation between the RIA and EIA (adjusted R-square = 0.95; Pearson correlation coefficient (PCC) = 0.98, P < 0.001). A difference between the RIA and EIA methods was not detected for E2 concentrations (P = 0.16), but the correlation between techniques was poor (adjusted R-squared = 0.73; PCC = 0.87, P = 0.002). There was no difference in the serum extraction efficiency as measured with 3H-P4 as opposed to without (P = 0.94). The two methods for the measurement of serum extraction efficiency were highly correlated (adjusted R-square = 0.83; PCC = 0.92, P < 0.001). The concordance correlation coefficient (CCC) showed an excellent agreement between RIA and EIA for P4 determination (0.89) and between HE and CE methods (0.90). Although the 95% limits of agreement of the Bland-Altman plots encompassed 89% (8/9) and 92% (12/13) of the differences between methods for P4 quantification and extraction respectively, the CCC indicated an excellent agreement among them. The CCC between RIA and EIA for E2 quantification was 0.68 which corresponds with a fair agreement; however, the 95% limits of agreement of the Bland-Altman plot encompassed 100% (9/9) of differences between methods. The EIA and CE methods are comparable alternatives to the RIA and HE methods, respectively, and can be used to quantify P4 and E2 for bovine serum.

      PubDate: 2017-04-06T22:29:01Z
       
  • Sexually active bucks counterbalance the seasonal negative feedback of
           estradiol on LH in ovariectomized goats
    • Abstract: Publication date: Available online 31 March 2017
      Source:Domestic Animal Endocrinology
      Author(s): A.L. Muñoz, D. Chesneau, H. Hernández, M. Bedos, G. Duarte, J. Vielma, L.A. Zarazaga, P. Chemineau, M. Keller, J.A. Delgadillo
      We showed previously that the permanent presence of bucks rendered sexually active by photoperiodic treatments, thereafter called photostimulated bucks, prevents the occurrence of seasonal anovulation; also, the introduction of these sexually active bucks, induces ovulations during seasonal anestrus. Here, we studied the response of ovariectomized goats bearing 12-mm subcutaneous implants filled or not with estradiol to sexually active males to determine 1) whether the permanent presence of such bucks prevents the decrease of LH despite the presence of a negative feedback by estradiol mimicking that of seasonal anestrus (experiment 1), and 2) whether the introduction of photostimulated bucks increases the plasma LH concentrations in spite of this negative feedback (experiment 2). In experiment 1, one group of goats remained in contact with sexually active bucks, whereas the other group remained in contact with control bucks. Plasma LH concentrations were high and did not differ with time or between groups of females from November to February (P > 0.05), when both types of bucks were sexually active. Afterwards, in goats in contact with control and sexually inactive bucks, LH concentrations decreased from March (P ≤ 0.01), and remained low until May, whereas LH levels remained high from March to May in goats in contact with the photostimulated bucks (P > 0.05). In experiment 2, two groups of females bearing empty subcutaneous implants, and two groups of goats bearing subcutaneous implants filled with estradiol, were exposed to control or photostimulated bucks. Plasma LH concentrations did not increase in goats bearing empty implants, when exposed to control or photostimulated bucks (from 2.01 ± 0.26 to 1.98 ± 0.31 ng/mL, and from 2.45 ± 0.29 to 2.42 ± 0.21 ng/mL respectively; P > 0.05). In contrast, plasma LH concentrations increased from 0.97 ± 0.41 to 2.80 ± 0.62 ng/mL in goats exposed to the photostimulated bucks and bearing estradiol implants (P < 0.05). Thus, the permanent presence of sexually active bucks prevented the decrease of plasma LH concentration in OVX + E2 goats during the seasonal anestrus, and the introduction of the photostimulated bucks increased the plasma LH concentrations in OVX + E2 goats during the seasonal anestrus. Therefore, we conclude that in both cases, the photostimulated bucks are able to reduce or counterbalance the seasonal negative feedback of estradiol on LH secretion.

      PubDate: 2017-04-06T22:29:01Z
       
  • Addition of insulin-like growth factor I to the maturation medium of
           bovine oocytes subjected to heat shock: effects on the production of
           reactive oxygen species, mitochondrial activity and oocyte competence
    • Abstract: Publication date: Available online 25 March 2017
      Source:Domestic Animal Endocrinology
      Author(s): I.J. Ascari, N.G. Alves, J. Jasmin, R.R. Lima, C.C.R. Quintão, G. Oberlender, E.A. Moraes, L.S.A. Camargo
      This study was performed to investigate the effects of Insulin-like growth factor-I (IGF-I) addition to in vitro maturation (IVM) medium on apoptosis, mitochondrial activity, ROS production, and developmental competence of bovine oocytes subjected to heat shock. Two temperatures (conventional: 24 h at 38.5°C, or heat shock: 12 h at 41°C followed by 12 h at 38.5°C) and three IGF-I concentrations (0, 25, and 100 ng/mL) were tested during IVM. The oocytes were then fertilized in vitro, and the presumptive zygotes were cultured until reaching the blastocyst stage. There was no interaction between temperature and IGF-I concentration for any variable evaluated (P > 0.05). The addition of IGF-I did not alter the proportion of nuclear maturation, TUNEL-positive oocytes and caspase-3 activity, or blastocyst proportion on days 7 and 8 post-fertilization. Furthermore, the total number of cells and the number of cells in the inner cell mass (ICM) in the blastocyst were not altered (P > 0.05). However, IGF-I increased (P < 0.05) the mitochondrial membrane potential and the production of ROS in oocytes and decreased (P < 0.05) the proportion of apoptotic cells in the ICM in blastocysts. Heat shock increased (P < 0.05) the proportion of TUNEL-positive oocytes and ROS production and reduced (P < 0.05) the mitochondrial membrane potential. Heat shock increased (P < 0.05) the apoptosis proportion in the ICM cells. In conclusion, supplementing IVM medium with IGF-I may increase the mitochondrial membrane potential and ROS production in oocytes and decrease apoptosis in the ICM in blastocysts. Heat shock for 12 h compromised oocyte developmental competence and increased apoptosis within the ICM cells of the blastocysts.

      PubDate: 2017-04-06T22:29:01Z
       
  • Response of Plasma Glucagon-like Peptide-2 to Feeding Pattern and
           Intraruminal Administration of Volatile Fatty Acids in Sheep
    • Abstract: Publication date: Available online 11 March 2017
      Source:Domestic Animal Endocrinology
      Author(s): M. Elsabagh, Y. Inabu, T. Obitsu, T. Sugino
      Glucagon-like peptide 2 (GLP-2), a gut peptide secreted by enteroendocrine L cells, has recently been identified as a key regulator of intestinal growth and absorptive function in ruminants. However, reports on GLP-2 secretion are few, and more information regarding its secretion dynamics is needed. In this study, two experiments were conducted to elucidate the daily rhythm of GLP-2 secretion in response to feeding regimen and to investigate the effect of volatile fatty acids (VFA) on GLP-2 release in sheep. In experiment 1, blood samples were collected over 3 d from 4 Suffolk mature wethers adapted to a maintenance diet fed once daily; day 1 sampling was preceded by 24 h of fasting to reach steady state. On days 1 and 3, samples were collected every 10 min from 11:00 to 14:00 on both days and then every 1 h until 00:00 on day 1 only; feed was offered at 12:00. On day 2, feed was withheld, and sampling was performed every hour from 01:00 to 00:00. In experiment 2, 5 Suffolk mature wethers were assigned to 5 treatment groups of intraruminal administration of saline, acetate, propionate, butyrate, or VFA mix (acetate, propionate, and butyrate in a ratio of 65:20:15) in a 5 × 5 Latin square design. Blood samples were collected at 0, 1.5, 3, 6, 9, 12, 15, 20, 25, 30, 40, 50, 60, 90, and 120 min relative to the beginning of administration )at 12:00). In both experiments, plasma GLP-2, glucagon-like peptide 1 (GLP-1), glucose, insulin, and β-hydroxy butyric acid (BHBA) levels were measured. In experiment 1, incremental area under the curve was greater (P < 0.05) post-feeding than pre-feeding on days 1 and 3 for GLP-2 and tended to be greater (P < 0.1) on day 1 for GLP-1. Plasma insulin, glucose, and BHBA levels increased (P < 0.05) on day 1 post-feeding. Plasma GLP-2 was poorly correlated with GLP-1 but positively correlated with insulin, glucose, and BHBA. In experiment 2, administration of butyrate and VFA mix remarkably increased plasma GLP-2 (P = 0.05) and BHBA (P < 0.0001) levels compared with those in other treatments. Plasma GLP-1 levels were higher with butyrate administration compared with those in the saline, acetate, and VFA mix (P = 0.019). Propionate administration increased plasma glucose (P = 0.013) and insulin (P = 0.053) levels. Thus, our data confirmed that GLP-2 release is responsive to feeding and might be promoted by BHBA produced by the rumen epithelial metabolism of butyrate. Further molecular- and cellular-level studies are needed to determine the role of butyrate as a signalling molecule for GLP-2 release.
      Teaser - Through dietary interventions, our data could contribute as a base for modulating the normal postprandial release of GLP-2 in order to improve gut function and nutrient uptake, and consequently, optimize production and health of ruminants.

      PubDate: 2017-03-13T00:05:24Z
       
  • Extended Low Dose Dexamethasone Suppression Test for Diagnosis of Atypical
           Cushing's Syndrome in Dogs
    • Abstract: Publication date: Available online 11 March 2017
      Source:Domestic Animal Endocrinology
      Author(s): K.M. Fowler, L.A. Frank, F. Morandi, J.C. Whittemore
      The purpose of this study was to evaluate extension of the low dose dexamethasone suppression test from 8 h to 12 h to detect possible hypercortisolemia associated with atypical hyperadrenocorticism (AHAC). Twelve client-owned dogs were enrolled in the study: 6 healthy dogs (group 1) and 6 dogs with suspected AHAC (group 2). Baseline EDTA plasma samples were collected for endogenous ACTH determination using an immunoradiometric assay. Serum samples were collected prior to and at 4, 8, 10, and 12 h post-administration of 0.01 mg/kg dexamethasone IV for cortisol concentration determination via chemiluminescent assay. Mean endogenous ACTH concentration did not differ between groups (group 1: 22.4 pg/mL, group 2: 20.0 pg/mL; P > 0.2). Mean baseline cortisol concentration also did not differ significantly between groups (group 1: 3.03 μg/dL, group 2: 4.95 μg/dL; P > 0.2), nor was there any difference in mean cortisol concentration between the groups at any other time point (P > 0.2). The cortisol concentration from 1 dog in group 2 suppressed to 0.7 μg/dL at 8 h but increased to 1.5 μg/dL at 10 h and 3.7 μg/dL at 12 h post-dexamethasone. Based on results of this study use of an extended LDDS test could not differentiate between healthy dogs and dogs with AHAC. Diagnosis of AHAC should continue to be based on prior established criteria until new testing has been identified.

      PubDate: 2017-03-13T00:05:24Z
       
  • Effect of fish meal supplementation on spatial distribution of lipid
           microdomains and on the lateral mobility of membrane-bound prostaglandin
           F2α receptors in bovine corpora lutea1
    • Abstract: Publication date: Available online 14 February 2017
      Source:Domestic Animal Endocrinology
      Author(s): M.R. Plewes, P.D. Burns, P.E. Graham, J.E. Bruemmer, T.E. Engle, B.G. Barisas
      This study examined the effects of fish meal supplementation on spatial distribution of lipid microdomains and lateral mobility of prostaglandin F2α (FP) receptors on cell plasma membranes of the bovine corpus luteum (CL). Beef cows were stratified by BW and randomly assigned to receive a corn gluten meal supplement (n = 4) or fish meal supplement (n = 4) for 60 d to allow incorporation of fish meal derived omega-3 fatty acids into luteal tissue. Ovaries bearing the CL were surgically removed between days 10 to 12 post-estrus corresponding to approximately day 60 of supplementation. A 200 mg sample of luteal tissue was analyzed for fatty acid content using GLC. The remaining tissue was enzymatically digested with collagenase to dissociate individual cells from the tissue. Cells were cultured to determine effects of dietary supplementation on lipid microdomains and lateral mobility of FP receptors. Luteal tissue collected from fish meal supplemented cows had increased omega-3 fatty acids content (P < 0.05). Lipid microdomain total fluorescent intensity was decreased in dissociated luteal cells from fish meal supplemented cows (P < 0.05). Micro and macro diffusion coefficients of FP receptors were greater for cells obtained from fish meal supplemented cows (P < 0.05). In addition, compartment diameter of domains was larger while resident time was shorter for receptors from cells obtained from fish meal supplemented cows (P < 0.05). Data indicate that dietary supplementation with fish meal increases omega-3 fatty acid content in luteal tissue causing disruption of lipid microdomains. This disruption leads to increased lateral mobility of the FP receptor, increased compartment sizes, and decreased resident time which may influence prostaglandin signaling in the bovine CL.

      PubDate: 2017-02-19T18:02:12Z
       
  • Relationship between Plasma Anti-Müllerian Hormone Concentrations during
           the Rearing Period and Subsequent Embryo Productivity in Japanese Black
           Cattle
    • Abstract: Publication date: Available online 4 February 2017
      Source:Domestic Animal Endocrinology
      Author(s): H. Nabenishi, G. Kitahara, S. Takagi, A. Yamazaki, T. Osawa
      To utilize plasma anti-Müllerian hormone (AMH) concentrations as early-stage markers for donor cow selection, we investigated the relationship between plasma AMH concentrations in Japanese black heifers and subsequent embryo productivity following superovulation treatment. Plasma AMH and NEFA concentrations in six heifers were evaluated once per month from 3 mo before successful AI for primiparity to 3 mo postpartum. Following calving, embryo collection by superovulation treatment was performed at 3–4-mo intervals. There were no significant differences in plasma AMH concentrations between the time points throughout the study period. There were, however, significant inter-animal differences in plasma AMH concentrations (p < 0.05). These findings suggest that plasma AMH concentrations were stable over time and individually specific. There were significant positive correlations between plasma AMH concentrations before AI and embryo productivity variables, including the number of ova/embryos (number of transferable embryos, degenerated embryos, and unfertilized oocytes) and numbers/proportions of fertilized and transferable embryos. There was no significant correlation between plasma AMH and NEFA concentrations throughout the study period. These findings reveal that plasma AMH concentrations during the rearing period can be used to predict subsequent embryo productivity following superovulation treatment, suggesting that these concentrations are useful early-stage markers for selecting donor cows.

      PubDate: 2017-02-05T13:55:13Z
       
  • Metabolic and inflammatory responses to the common sweetener stevioside
           and a glycemic challenge in horses with equine metabolic syndrome
    • Abstract: Publication date: Available online 4 February 2017
      Source:Domestic Animal Endocrinology
      Author(s): S.E. Elzinga, B. Rohleder, B. Schanbacher, K. McQuerry, V.D. Barker, A.A. Adams
      Extracts derived from the leaves of the stevia plant (stevioside) are commonly used as sweeteners for humans and horses. Stevioside appears to be safe for human consumption, including for individuals with insulin dysregulation. In the horse, the safety or metabolic effects of stevioside on normal animals or on those with metabolic dysfunction are unknown. Furthermore, the inflammatory response to a glycemic challenge or to stevioside in horses is not well defined. Therefore, the objective of this study was to measure the effects of stevioside and a glycemic challenge on insulin, glucose, and inflammatory responses in horses with a common metabolic dysfunction (equine metabolic syndrome or EMS) compared with non-EMS controls. To accomplish this, 15 horses were selected; 8 EMS and 7 age-matched controls. An oral sugar test (OST) was performed using Karo® corn syrup (karo) or stevioside in a random crossover design. Horses were given 0.15 mL/ kg body weight of karo or its equivalent grams of sugar in stevia dissolved in water. Blood samples were collected by jugular venipuncture prior to administration of either stevia or karo and at 60 and 240 min post administration. Serum was used for glucose and insulin determination and plasma for isolation of peripheral blood mononuclear cells (PBMCs) for inflammatory cytokine analysis via flow cytometry and reverse transcription polymerase chain reaction (RT-PCR). Stevia appeared to stimulate lower glycemic and insulinemic responses when compared to karo, in particular in EMS horses. EMS and control horses had inverse inflammatory responses to administration of either stevia or karo with EMS horses having a pro-inflammatory response (P < 0.05). These data provide evidence as to why horses with EMS may be predisposed to developing laminitis, potentially as a result of an exaggerated inflammatory response to glycemic and insulinemic responses. Further, the data provide new avenues for exploring mechanisms behind the syndrome, in particular when utilizing a glycemic challenge.

      PubDate: 2017-02-05T13:55:13Z
       
  • Is progesterone the key regulatory factor behind ovulation rate in
           sheep'
    • Authors: P.M. Bartlewski; J. Sohal; V. Paravinja; T. Baby; M.E.F. Oliveira; M. Murawski; T. Schwarz; D.A. Zieba; D.H. Keisler
      Pages: 30 - 38
      Abstract: Publication date: January 2017
      Source:Domestic Animal Endocrinology, Volume 58
      Author(s): P.M. Bartlewski, J. Sohal, V. Paravinja, T. Baby, M.E.F. Oliveira, M. Murawski, T. Schwarz, D.A. Zieba, D.H. Keisler
      Ovarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes and there is a great deal of evidence that luteal progesterone (P4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of this study was to determine whether or not extending the duration of the luteal phase in prolific sheep to that typically seen in nonprolific breeds would alter the follicle wave dynamics and ovulation rate. In 2 separate experiments, exogenous P4 (7.5 mg per ewe intramuscularly) was administered on day 11 at PM and day 12 at AM (day 0 = first ovulation of the interovulatory interval studied) in moderately prolific Rideau Arcott × Polled Dorset ewes (experiment 1, n = 8) and highly prolific Olkuska ewes (experiment 2, n = 7; TRT), whereas the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily, and jugular blood samples were drawn twice a day from day 9 until the next ovulation. Progesterone injections resulted in relatively uniform increments in serum P4 levels, but the mean duration of the interovulatory interval did not differ (P > 0.05) between TRT and CTR groups of ewes in either experiment. The mean ovulation rate post-treatment was 1.6 ± 0.2 vs 3.2 ± 0.4 (experiment 1, P < 0.001) and 3.2 ± 0.8 vs 4.0 ± 1.0 (experiment 2, P > 0.05) in TRT vs CTR, respectively. The number and percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 0.25 ± 0.16 vs 1.75 ± 0.45 (P < 0.01) and 25.0 ± 16.4% vs 75.0 ± 16.4% (P < 0.05) in experiment 1, and 0.50 ± 0.30 vs 1.60 ± 0.40 (P < 0.05) and 13.8 ± 9.0% vs 53.4 ± 16.7% (P < 0.05) in experiment 2, for TRT vs CTR, respectively. In summary, administration of P4 at the end of diestrus decreased the incidence of ovulations from the penultimate wave of the estrous cycle in both the moderately and highly prolific strains of sheep, but it reduced the ovulation rate only in moderately prolific ewes.

      PubDate: 2016-09-16T05:14:08Z
      DOI: 10.1016/j.domaniend.2016.06.006
      Issue No: Vol. 58 (2016)
       
  • Transcript levels of genes implicated in steroidogenesis in the testes and
           fat tissue in relation with androstenone accumulation in fat of pubertal
           pigs
    • Authors: A. Robic; K. Feve; J. Riquet; A. Prunier
      Pages: 1 - 9
      Abstract: Publication date: Available online 9 April 2016
      Source:Domestic Animal Endocrinology
      Author(s): A. Robic, K. Feve, J. Riquet, A. Prunier
      The present study was performed to measure mRNA levels of steroidogenic enzymes in testes and fat tissue and determine whether they are related to fat androstenone level. Real time PCR experiments were performed on 26 testes and 12 adipose tissue samples from pubertal boars using 21 genes. The absence of significant correlations between fat androstenone and the transcriptional activity of the SRD5A2 and SRD5A3 genes but the high correlation coefficient with that of the SRD5A1 gene (r = 0.62, P < 0.05) suggest that the enzyme coded by SRD5A1 is mainly responsible for the last step of androstenone synthesis. The testicular transcriptional activities of CYP17, CYP11A1, CYP19A, AKR1C-pig6, SRD5A1, LHCGR, and AR were significantly correlated. Only transcriptional levels of CYP17, CYP11A1, CYP19A, SRD5A1 and AKR1C-pig6 were correlated with the fat concentration of androstenone (0.57 < r < 0.70, P < 0.05) confirming that the amount of androstenone stored in fat is related to the production in testes of androstenone and more generally to all sex steroids. Altogether, our data are in favor of a preponderant role of AKR1C-pig6 instead of HSD17B3 for testicular synthesis of steroids. Concerning fat tissue, our data do not support a significant de novo biosynthesis of steroids in porcine adipose tissues. The presence of transcripts coding for steroid enzymes, especially those of AKR1C-pig6, suggests that steroids can be transformed. None of transcript abundance was related to androstenone accumulation (P > 0.1). Therefore, steroids synthesized elsewhere can be transformed in fat tissue but synthesis of androstenone is unlikely.

      PubDate: 2016-04-09T14:44:46Z
      DOI: 10.1016/j.domaniend.2016.03.008
      Issue No: Vol. 57 (2016)
       
  • A transcriptional cofactor YAP regulates IFNT expression via transcription
           factor TEAD in bovine conceptuses
    • Authors: K. Kusama; R. Bai; T. Sakurai; H. Bai; A. Ideta; Y. Aoyagi; K. Imakawa
      Pages: 21 - 30
      Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): K. Kusama, R. Bai, T. Sakurai, H. Bai, A. Ideta, Y. Aoyagi, K. Imakawa
      Interferon tau (IFNT) is the pregnancy recognition protein in all ruminants, and its expression is restricted to trophoblast cells. Interferon tau production increases as the conceptus elongates; however, its expression is downregulated soon after the initiation of conceptus attachment to the uterine epithelium. Our previous study identified that among 8 bovine IFNT genes, only 2 forms of IFNTs, IFNT2 and IFN-tau-c1, were expressed by the conceptuses during the periattachment period. To characterize whether Hippo signaling including a transcription cofactor yes-associated protein (YAP) was involved in the IFNT regulation, we examined the expression and effects of YAP and/or TEAD in human choriocarcinoma JEG3 and bovine trophoblast CT-1 cells, and in bovine conceptuses obtained from day 17, 20 or 22 pregnant animals (pregnant day 19.5 = day of conceptus attachment to the endometrium). YAP was expressed in bovine conceptuses and transfection of YAP or TEAD4, a transcription factor partner of YAP, expression plasmid increased the luciferase activity of IFNT2 and IFN-tau-c1 reporter plasmids in JEG3 cells. In the presence of YAP expression plasmid, TEAD2 or TEAD4 expression plasmid further upregulated transcriptional activity of IFNT2 or IFN-tau-c1 constructs, which were substantially reduced in the absence of the TEAD-binding site on IFNT2 or IFN-tau-c1 promoter region in JEG3 cells. In CT-1 cells, treatment with TEAD2, TEAD4, or YAP small-interfering RNA downregulated endogenous IFNT expression. It should be noted that TEAD2 and TEAD4 were predominantly localized in the nuclei of trophectoderm of Day 17 conceptuses, but nuclear localization appeared to be lower in those cells of conceptuses on days 20 and 22 of pregnancy. Moreover, the binding of TEAD4 to the TEAD-binding site of the IFN-tau-c1 promoter region in day 17 conceptuses was less in day 20 and 22 conceptuses. Furthermore, the level of YAP phosphorylation increased in day 20 and 22 conceptuses. These results indicated that although YAP/TEAD had the ability to up-regulate IFNT gene transcription on day 17, IFNT2 or IFN-tau-c1 was down-regulated following changes in the localization of TEAD2 and TEAD4 from the nucleus to the cytoplasm and increases in phosphorylation and degradation of YAP. These data suggest that TEAD relocation and/or YAP degradation following its phosphorylation down-regulates IFNT gene transcription after conceptus attachment to the uterine endometrium.

      PubDate: 2016-06-18T18:51:23Z
      DOI: 10.1016/j.domaniend.2016.05.002
      Issue No: Vol. 57 (2016)
       
  • A systematic review and meta-analysis of salivary cortisol measurement in
           domestic canines
    • Authors: M.L. Cobb; K. Iskandarani; V.M. Chinchilli; N.A. Dreschel
      Pages: 31 - 42
      Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): M.L. Cobb, K. Iskandarani, V.M. Chinchilli, N.A. Dreschel
      Salivary cortisol is widely used as an indicator of stress and welfare in canine research. However, much remains unclear about the basic features of this hormone marker in domestic dogs. This systematic review and meta-analysis aimed to determine a reference range for cortisol concentration in the saliva of dogs and examine how canine characteristics, environmental effects and experimental considerations relate to salivary cortisol concentrations. A systematic review of literature databases and conference proceedings from 1992 to 2012 identified 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted via email, and 31 raw data sets representing a total of 5,153 samples from 1,205 dogs were shared. Meta-analysis provided a cortisol concentration range of 0 to 33.79 μg/dL (mean 0.45 μg/dL, SEM 0.13). Significant effects (P < 0.05) were found for sex and neuter status, age, regular living environment, time in environment before testing, testing environment, owner presence during testing, and collection media. Significant effects were not found for dog breed, body weight, dog type, coat color, assay type, exercise, eating, or use of salivary stimulant. Care should be taken when using cortisol studies for dogs at a group or population level as there is a large amount of intraindividual and interindividual variability and external variables could influence salivary cortisol concentration. This analysis highlights the importance of carefully controlling experimental design to compare samples within and between individual dogs, as well as establishing and using best practices for saliva collection. Caution should be exercised in comparing different studies, as the results could be the reflection of a plethora of factors.

      PubDate: 2016-06-18T18:51:23Z
      DOI: 10.1016/j.domaniend.2016.04.003
      Issue No: Vol. 57 (2016)
       
  • Systemic and intrafollicular components of follicle selection in mares
    • Abstract: Publication date: Available online 22 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther
      Mares are superb models for study of follicle selection owing to similarities between mares and women in relative follicle diameters at specific events during the follicular wave and follicle accessibility for experimental sampling and manipulation. Usually only one major follicular wave with a dominant follicle (DF) greater than 30 mm develops during the 22 to 24 d of the equine estrous cycle and is termed the primary or ovulatory wave. A major secondary wave occasionally (25%) develops early in the cycle. Follicles of the primary wave emerge at 6 mm on Day 10 or 11 (Day 0 = ovulation). The 2 largest follicles begin to deviate in diameter on about Day 16 when the future DF and largest subordinate follicle (SF) are 23 mm and 20 mm. The deviation process begins the day before diameter deviation as indicated in the future DF but not in the future SF by (1) increase in prominence of an anechoic layer and vascular perfusion of the wall and (2) increase in follicular fluid concentrations of insulin-like growth factor 1 (IGF1), vascular endothelial growth factor , estradiol, and inhibin-A. A systemic component of the deviation process is represented by suppression of circulating FSH from secretion of inhibin and estradiol from the developing DF. Production of inhibin is stimulated by IGF1 and LH, and estradiol is stimulated by LH and not by IGF1 in mares. A local intrafollicular component involves the production of IGF1 which apparently increases the responsiveness of the future DF to FSH. The roles of the IGF system have been well studied in mares, but the effect of IGF1 on increasing the sensitivity of the follicle cells to FSH is based primarily on studies in other species. The greater response of the future DF than the SF to the low concentrations of FSH is the essence of selection. During the common-growth phase that precedes deviation, diameter of the 2 largest follicles increases in parallel on average when normalized to emergence or retrospectively to deviation. Study of individual waves indicates that (1) the 2 follicles change ranks (relative diameters) during the common-growth phase in about 30% of primary waves and (2) after ablation of 1, 2, or 3 of the largest follicles at the expected beginning of deviation, the next largest retained follicle becomes the DF indicating that several follicles have the capacity for dominance; therefore, it is proposed that the deviation process represents the entire mechanism of follicle selection in mares.

      PubDate: 2016-12-29T12:17:28Z
       
  • Short Communication: Relationship between serum adiponectin concentration,
           body condition score and peripheral tissue insulin response of dairy cows
           during the dry period
    • Abstract: Publication date: Available online 18 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. De Koster, C. Urh, M. Hostens, W. Van den Broeck, H. Sauerwein, G. Opsomer
      The aim of the present study was to describe the relationship between serum adiponectin concentration and peripheral tissue insulin response in dairy cows with a variable body condition score (BCS) during the dry period. Cows were selected at the beginning of the dry period based on BCS (BCS < 3.75, n = 4; BCS > 3.75, n = 5). Animals were followed from the beginning of the dry period by weekly blood sampling and assessment of BCS and backfat thickness. Weekly blood samples were analyzed for adiponectin concentration using a bovine specific ELISA. Hyperinsulinemic euglycemic clamp tests were performed at the end of the dry period to measure peripheral tissue insulin response. Insulin dose response curves were established for both glucose and fatty acid metabolism. Regression analysis revealed that the serum concentrations of adiponectin dropped at the end of the dry period (P < 0.05) and were negatively associated BCS (P < 0.05). At the level of the glucose metabolism, serum concentrations of adiponectin were positively correlated with insulin responsiveness (reflecting the maximal effect of insulin; r = 0.76, P < 0.05), but not with insulin sensitivity (reflecting the insulin concentration needed to achieve halfmaximal effect; r = - 0.54, P = 0.13). At the level of the fatty acid metabolism greater adiponectin concentrations were negatively correlated with lower NEFA levels during the HEC test reflecting the insulin responsiveness of the NEFA metabolism (r = - 0.61, P = 0.08), whereas there was no association with the insulin sensitivity of the NEFA metabolism (r = - 0.16, P = 0.67). In conclusion, serum concentrations of adiponectin concentration were negatively associated with the BCS of dairy cows during the dry period, and positively associated with insulin responsiveness of the glucose and fatty acid metabolism.

      PubDate: 2016-12-22T11:49:52Z
       
  • The impact of flutamide on prostaglandin F2α synthase and prostaglandin
           F2α receptor expression, and prostaglandin F2α concentration in the
           porcine corpus luteum of pregnancy
    • Abstract: Publication date: Available online 11 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): M. Grzesiak, K. Knapczyk-Stwora, M. Slomczynska
      Recently we have indicated that flutamide-induced androgen deficiency diminished progesterone production in the porcine CL during late pregnancy and before parturition, as a sign of functional luteolysis. In pigs, the main luteolytic factor is prostaglandin F2α (PGF2α), which acts via specific receptors (PTGFRs), and its biosynthesis is catalyzed by prostaglandin F2α synthase (PGFS). The current study investigated the impact of flutamide on luteal PGFS and PTGFR expression, as well as intraluteal PGF2α content during pregnancy in pigs. Flutamide (50 mg/kg BW per day, for 7 d) or corn oil (control groups) were administered subcutaneously into pregnant gilts (n = 3 per group) between 83-89 (GD90) or 101-107 (GD108) days of gestation (GD). On GD90 and GD108 ovaries were collected and CLs were obtained. Real-time PCR and Western blot analyses were conducted to quantify PGFS and PTGFR mRNA and protein expression, respectively. In addition, immunohistochemical localization of both proteins was performed and the concentration of PGF2α was analyzed by enzyme immunoassay method (EIA). Flutamide caused up-regulation of PGFS mRNA and protein in GD90F (P = 0.008; P = 0.008, respectively) and GD108F (P = 0.041; P = 0.009, respectively) groups. The level of PTGFR mRNA increased only in the GD90F (P = 0.007) group, while PTGFR protein expression was greater in both gestational periods (P = 0.035; P = 0.038, respectively). On GD90 PGFS was immunolocalized in the cytoplasm of large luteal cells only, whereas on GD108 sparse small luteal cells also displayed positive staining. PTGFR showed membranous localization within large luteal cells on both days of pregnancy. In luteal tissue, PGF2α concentration was greater after flutamide exposure on both days (P = 0.041; P = 0.038, respectively), when compared to control groups. Overall, the enhanced luteal PGF2α content due to increased PGFS expression following flutamide administration might contribute to premature CL regression. Moreover, higher PTGFR protein levels indicate enhanced sensitivity of luteal cells to PGF2α under androgen deficiency.

      PubDate: 2016-12-14T11:08:55Z
       
  • G Protein-Coupled Receptor 34 in Ovarian Granulosa Cells of Cattle:
           Changes during Follicular Development and Potential Functional
           Implications
    • Abstract: Publication date: Available online 11 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): L.J. Spicer, L.F. Schütz, J.A. Williams, N.B. Schreiber, J.R. Evans, M.L. Totty, J.N. Gilliam
      Abundance of G protein-coupled receptor 34 (GPR34) mRNA is greater in granulosa cells (GC) of cystic vs. normal follicles of cattle. The present experiments were designed to determine if GPR34 mRNA in GC changes during selection and growth of dominant follicles in cattle as well as to investigate the hormonal regulation of GPR34 mRNA in bovine GC in vitro. In Exp. 1, estrous cycles of non-lactating cows were synchronized and then ovariectomized on either day 3-4 or 5-6 after ovulation. GPR34 mRNA abundance in GC was 2.8- to 3.8-fold greater (P < 0.05) in small (1-5 mm) and large (> 8 mm) estrogen-inactive dominant follicles than in large estrogen-active follicles. Also, GPR34 mRNA tended to be greater (P < 0.10) in F2 than F1 follicles on day 3-4 post-ovulation. In Exp. 2-7, ovaries were collected at an abattoir and GC were isolated and treated in vitro. Expression of GPR34 was increased (P < 0.05) 2.2-fold by IGF1. Tumor necrosis factor (TNF)-α decreased (P < 0.05) the IGF1-induced GPR34 mRNA abundance in small-follicle GC, whereas IGF1 decreased (P < 0.05) GPR34 expression by 45% in large-follicle GC. Treatment of small-follicle GC with either IL-2, prostaglandin E2 or angiogenin decreased (P < 0.05) GPR34 expression whereas FSH, cortisol, wingless 3A or hedgehog proteins did not affect (P > 0.10) GPR34 expression. In Exp. 6 and 7, two presumed ligands of GPR34, L-a-lysophosphatidylserine (LPPS) and LPP-ethanolamine, increased (P < 0.05) GC numbers and estradiol production by twofold or more in small-follicle GC, and this response was only observed in IGF1-treated GC. In conclusion, GPR34 is a developmentally and hormonally regulated gene in GC, and its presumed ligands enhance IGF1-induced proliferation and steroidogenesis of bovine GC.

      PubDate: 2016-12-14T11:08:55Z
       
  • Glucogenic treatment creates an optimal metabolic milieu for the
           conception period in ewes
    • Abstract: Publication date: Available online 11 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): C. Porcu, V. Pasciu, S. Succu, E. Baralla, M.E. Manca, E. Serra, G.G. Leoni, M. Dattena, G.C. Bomboi, G. Molle, S. Naitana, F. Berlinguer
      This study determined the influence of a short-term glucogenic nutritional treatment on circulating concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), non-esterified fatty acids (NEFA), and urea, and on their correspondent levels in follicular fluid (FF) collected 12 h after the end of the treatment. After estrous synchronization with intravaginal progestagen-impregnated sponges, 20 Sarda ewes were randomly allocated into two experimental groups (GLU and WAT) and, from day 7 to day 10 (day 0 = day of sponge removal), the GLU group was gavaged with a glycogenic mixture, whereas the WAT group was gavaged with water (control group). Follicular development was stimulated by FSH administration from day 8 to 10. At day 11, ovaries were collected and follicular fluid processed. Plasma changes were assessed from day 6 to 11. In GLU group circulating concentration of glucose (P < 0.0001), insulin (P < 0.0001) and IGF-1 (P < 0.01) rose significantly, whereas NEFA and urea concentrations decreased (P < 0.0001), as compared to controls. In particular, in FF the higher glucose concentrations found in GLU ewes compared to controls (P < 0.0001) were not accompanied by any increase in insulin and IGF-1 concentrations. NEFA (P < 0.0001) and urea (P < 0.0001) were lower in FF of GLU than WAT group, although NEFA clearance in the ovary proved to be less efficient than at the systemic level. No significant difference between groups was found in FF concentrations of pregnancy-associated plasma protein A (a protease regulating the levels of free IGF-1 in follicles), glutathione, and in its total anti-oxidant capacity. These results suggest that glycogenic mixture administration creates a suitable follicular micro-environment for the conception period in dairy ewes.

      PubDate: 2016-12-14T11:08:55Z
       
  • Feline hypersomatotropism and acromegaly tumorigenesis: A potential role
           for the AIP gene
    • Abstract: Publication date: Available online 8 December 2016
      Source:Domestic Animal Endocrinology
      Author(s): C.J. Scudder, S.J. Niessen, B. Catchpole, R.C. Fowkes, D.B. Church, Y. Forcada
      Acromegaly in humans is usually sporadic, however up to 20% of familial isolated pituitary adenomas are caused by germline sequence variants of the aryl-hydrocarbon-receptor interacting protein (AIP) gene. Feline acromegaly has similarities to human acromegalic families with AIP mutations. The aim of this study was to sequence the feline AIP gene, identify sequence variants and compare the AIP gene sequence between feline acromegalic and control cats, and in acromegalic siblings. The feline AIP gene was amplified through PCR using whole-blood genomic DNA from 10 acromegalic and 10 control cats, and three sibling pairs affected by acromegaly. PCR products were sequenced and compared to the published predicted feline AIP gene. A single non-synonymous SNP was identified in exon 1 (AIP:c.9T>G) of two acromegalic cats and none of the control cats, as well as both members of one sibling pair. The region of this SNP is considered essential for the interaction of the AIP protein with its receptor. This sequence variant has not previously been reported in humans. Two additional synonymous sequence variants were identified (AIP:c.481C>T and AIP:c.826C>T). This is the first molecular study to investigate a potential genetic cause of feline acromegaly and identified a non-synonymous AIP single nucleotide polymorphism in 20 % of the acromegalic cat population evaluated, as well as in one of the sibling pairs evaluated.

      PubDate: 2016-12-08T09:51:03Z
       
  • Supplementation of metabolizable protein during late gestation and fetal
           number impact ewe organ mass, maternal serum hormone and metabolite
           concentrations, and conceptus measurements
    • Abstract: Publication date: January 2017
      Source:Domestic Animal Endocrinology, Volume 58
      Author(s): T.J. Swanson, L.A. Lekatz, M.L. Van Emon, G.A. Perry, C.S. Schauer, K.R. Maddock Carlin, C.J. Hammer, K.A. Vonnahme
      To examine the effects of maternal metabolizable protein (MP) supplementation during late gestation on serum hormone and metabolites and organ masses, multiparous ewes (n = 45) carrying singletons or twins were allotted randomly (within pregnancy group) to 1 of 3 treatments: 60% (MP60), 80% (MP80), or 100% (MP100) of MP requirements. Blood samples were drawn before the initiation of diets (day 100) and before slaughter (day 130) for chemistry panel analysis and weekly for hormone analysis including progesterone (P4) and estradiol-17β (E2). At day 130, ewe organ masses were recorded. Despite being fed isocaloric diets, MP60 ewes gained less weight throughout pregnancy compared with MP80 and MP100 ewes which were similar. Although diet did not impact E2 or P4 concentrations, ewes carrying twins had greater (P < 0.05) concentrations of both as gestation advanced. Albumin, aspartate aminotransferase, and total protein were reduced (P < 0.05) in MP60 compared with MP100 ewes near term. There was a diet by fetal number interaction (P = 0.03) for lactate dehydrogenase. Twin-carrying MP80 ewes had greater lactate dehydrogenase compared with all other groups on day 130 of gestation. Ewes that were fed MP80 had greater body weight on day 130 of gestation compared with MP60 ewes. Kidney and heart weights were lighter in MP60 ewes compared with MP80 ewes. There was a maternal diet by fetal number interaction (P = 0.05) on fetal weight per unit empty ewe body weight. In ewes carrying singletons, MP60 ewes supported less fetal weight compared with MP100. In contrast, MP60 ewes supported more fetal mass compared with MP100 ewes when carrying twins. The level of protein, and not just total energy, in the diet appears to impact some aspects of the maternal system. Moreover, it appears some measurements of mobilizing maternal body resources are enhanced in ewes carrying twins.

      PubDate: 2016-12-01T07:45:31Z
       
  • Bone morphogenetic protein 4 and bone morphogenetic protein receptor
           expression in the pituitary gland of adult dogs in healthy condition and
           with ACTH-secreting pituitary adenoma
    • Abstract: Publication date: January 2017
      Source:Domestic Animal Endocrinology, Volume 58
      Author(s): A. Sato, H. Ochi, Y. Harada, T. Yogo, N. Kanno, Y. Hara
      The purpose of this study was to investigate the expression of bone morphogenetic protein 4 (BMP4) and its receptors, bone morphogenetic protein receptor I (BMPRI) and BMPRII, in the pituitary gland of healthy adult dogs and in those with ACTH-secreting pituitary adenoma. Quantitative polymerase chain reaction analysis showed that the BMP4 messenger RNA expression level in the ACTH-secreting pituitary adenoma samples was significantly lower than that in the normal pituitary gland samples (P = 0.03). However, there were no statistically significant differences between samples with respect to the messenger RNA expression levels of the receptors BMPRIA, BMPRIB, and BMPRII. Double-immunofluorescence analysis of the normal canine pituitary showed that BMP4 was localized in the thyrotroph (51.3 ± 7.3%) and not the corticotroph cells. By contrast, BMPRII was widely expressed in the thyrotroph (19.9 ± 5.2%) and somatotroph cells (94.7 ± 3.6%) but not in the corticotroph cells (P < 0.001, thyrotroph cells vs somatotroph cells). Similarly, in ACTH-secreting pituitary adenoma, BMP4 and BMPRII were not expressed in the corticotroph cells. Moreover, the percentage of BMP4-positive cells was also significantly reduced in the thyrotroph cells of the surrounding normal pituitary tissue obtained from the resected ACTH-secreting pituitary adenoma (8.3 ± 7.9%) compared with that in normal canine pituitary (P < 0.001). BMP4 has been reported to be expressed in corticotroph cells in the human pituitary gland. Therefore, the results of this study reveal a difference in the cellular pattern of BMP4-positive staining in the pituitary gland between humans and dogs and further revealed the pattern of BMPRII-positive staining in the dog pituitary gland. These species-specific differences regarding BMP4 should be considered when using dogs as an animal model for Cushing's disease.

      PubDate: 2016-12-01T07:45:31Z
       
  • Molecular cloning, tissue distribution, and pharmacological
           characterization of melanocortin-4 receptor in grass carp
           (Ctenopharyngodon idella)
    • Abstract: Publication date: Available online 21 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): L. Li, Z. Yang, Y.-P. Zhang, S. He, X.-F. Liang, Y.-X. Tao
      Melanocortin-4 receptor (MC4R) plays a pivotal role in the mediation of leptin action on food intake and energy expenditure in mammals. The MC4R has also been identified in several teleosts and its importance in the regulation of fish energy homeostasis is emerging. We herein reported on the molecular cloning, tissue distribution, and pharmacological characterization of MC4R in grass carp (Ctenopharyngodon idella), an economically and ecologically important fish. We showed that grass carp MC4R (ciMC4R) consisted of a 981 bp open reading frame encoding a protein of 326 amino acids, highly homologous (>95%) to several teleost MC4Rs. Phylogenetic and synteny analysis further indicated ciMC4R was closely related to piscine MC4Rs. Using RT-PCR, we found that mc4r mRNA was expressed in the brain as well as various peripheral tissues in grass carp. The pharmacological properties of ciMC4R were investigated using four agonists, including α-melanocyte stimulating hormone (α-MSH), β-MSH, [Nle4, D-Phe7]-MSH (NDP-MSH) and adrenocorticotropic hormone (ACTH). We showed that all four ligands could bind to ciMC4R and initiate dose-dependent intracellular cAMP accumulation. Grass carp MC4R had the highest affinity for NDP-MSH. Both NDP-MSH and ACTH (1-24) exhibited higher potencies compared to the other two endogenous agonists. The ciMC4R was constitutively active, with significantly increased basal cAMP level compared with that of human MC4R (P < 0.01). The availability of ciMC4R and its pharmacological characteristics provide a basis for future investigation of its functional roles in regulating diverse physiological processes and novel insights into understanding the mechanism of food habit transition in grass carp.

      PubDate: 2016-11-23T05:33:53Z
       
  • A novel method for assessing chronic cortisol concentrations in dogs using
           the nail as a source
    • Abstract: Publication date: Available online 17 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): Z. Mack, H.B. Fokidis
      Cortisol, a glucocorticoid secreted in response to stress is used to assess adrenal function and mental health in clinical settings. Current methods assess cortisol sources that reflect short-term secretion that can vary with current stress state. Here we present a novel method for the extraction and quantification of cortisol from the dog nail using solid phase extraction coupled to enzyme-linked immunosorbent assay. Validation experiments demonstrated accuracy (r = 0.836, P < 0.001) precision (15.1% CV), and repeatability (14.4% CV) with this method. Furthermore, nail cortisol concentrations were positively correlated an established hair cortisol method (r = 0.736, P < 0.001). Nail cortisol concentrations did not differ with dog sex, breed, age, or weights, however sample size limitations may preclude statistical significance. Nail cortisol may provide information on cortisol secretion integrated over the time corresponding to nail growth and may be useful as a tool for diagnosing stress and adrenal disorders in dogs.

      PubDate: 2016-11-23T05:33:53Z
       
  • Plasma transport of ergocalciferol and cholecalciferol and their
           25-hydroxylated metabolites in dairy cows
    • Abstract: Publication date: Available online 16 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): L. Hymøller, S.K. Jensen
      In cattle there are 2 significant forms of vitamin D: ergocalciferol (ERG) from fungi on roughage and cholecalciferol (CHO) from vitamin supplements or endogenous synthesis in the skin. The hypothesis of the present study is that vitamin D from the 3 sources is transported in different plasma fractions in the body. This is hypothesised to explain the lower efficiency of ERG compared to CHO in securing a sufficient plasma status of 25-hydroxyvitamin D and explain the inefficient excretion of dietary CHO into milk compared to endogenous CHO. 20 vitamin D depleted cows were assigned to 5 treatments: D2 - housed indoor and fed 625 μg/d (25.000 IU) ERG; D3 - housed indoor and fed 625 μg/d CHO; D2+D3 - housed indoor and fed 625 μg/d ERG and 625 μg/d CHO; SUN - let out for daily pasture to facilitate CHO synthesis from sunlight; and D2+SUN - fed 625 μg/d ERG and let out for daily pasture. Blood samples were taken twice weekly and plasma fractionated by ultracentrifugation into 3 fractions: light lipoprotein (LLP), heavy lipoprotein (HPL), and protein and analysed for content of ERG and CHO and their liver derived metabolites 25-hydroxyergocalciferol (25ERG) and 25-hydroxycholecalciferol (25CHO), respectively. Liver biopsies were taken on the last day of the study to asses gene expression related to vitamin D metabolism. During 4 wk of study the vitamin D status in plasma increased to 19.3 to 22.8 ng/mL 25ERG in ERG treated cows with the highest concentration in D2 (P ≤ 0.05) and to 25.0 to 33.4 ng/mL 25CHO in pasture or CHO treated cows with the highest concentration in SUN (P ≤ 0.01). In plasma fractions CHO was mainly found in the HLP fraction whereas 25CHO was almost exclusively found in the protein fraction, probably due to its reported high binding affinity to vitamin D binding protein. Between 70 and 90% of 25ERG was found in the protein fraction and the remaining 25ERG in HLP, whereas ERG was found in both HLP and LLP fractions. In liver tissue the expression of vitamin D-25-hydroxylase was lower in D2+D3 (P ≤ 0.05) and SUN (P ≤ 0.05) than in the remaining groups and the vitamin D receptor (VDR) was expressed in the liver to a larger extent in D2+SUN than in D2+D3 (P ≤ 0.05) and SUN (P ≤ 0.05). In conclusion, different plasma transport mechanisms may explain the lower physiological efficiency of ERG compared to CHO in securing the vitamin D status in plasma but do not explain the lower efficiency of synthetic CHO compared to endogenous CHO from sunlight or UV light in securing a high CHO content in milk.

      PubDate: 2016-11-17T03:35:37Z
       
  • Sunlight exposure increases Vitamin D sufficiency in growing pigs fed a
           diet formulated to exceed requirements
    • Abstract: Publication date: Available online 11 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): B.M. Alexander, B.C. Ingold, J.L. Young, S.R. Fensterseifer, P.J. Wechsler, K.J. Austin, D.E. Larson-Meyer
      Traditional confinement practices limits exposure to sunlight and Vitamin D synthesis, and vitamin insufficiency occurs even with dietary supplementation. The aim of this study was to determine the effect of limited sun exposure on serum concentration of vitamin D and the expression of vitamin D synthesizing enzymes in the liver and kidney of pigs on a vitamin D sufficient diet. White-pigmented grower pigs (29.7 ± 2.3 kg) fed 15% CP diet ad libitum providing >1200 IU vitamin D3/kg of feed were exposed to sunlight for 1 h each day at solar noon for 14 d at the spring equinox (March pigs, n=10) or summer solstice (June pigs, n=5) and again prior to slaughter in June (March pigs) and September (June pigs). Blood for the analysis of 25(OH)D was collected prior to and following sunlight exposure. Traditionally housed pigs served as controls. Following initial sun exposure, blood samples were collected from June pigs daily for 5 d and weekly for 8 wk to determine vitamin D3 and 25(OH)D decay, respectively. Kidney and liver samples were collected from the June pigs at slaughter following sun exposure for analysis of mRNA expression of vitamin D binding protein and synthesizing/degrading enzymes. ADG was not influenced (P > 0.5) by sunlight exposure. June pigs had fewer days on feed, lower (P = 0.003) ADG and were slaughtered at a lighter (P < 0.001) weight. Exposure to sunlight increased (P < 0.001) 25(OH) vitamin D for all pigs. March pigs, obtained from a Midwest producer, had lower (P < 0.001) concentration of 25(OH)D than June pigs born on-farm. Initial sunlight exposure increased serum concentration of 25(OH)D in March pigs by 200% and June pigs by 67%. Serum concentration of vitamin D3 was decreased (P < 0.05) by 72 h with 25(OH)D decreased (P < 0.05) by wk 4 following exposure. Expression of vitamin D binding protein, vitamin D synthesizing CYP2R1, CYP27A1, CYP2D25 or degrading enzyme CYP24A1 were not influenced (P ≥ 0.19) by sunlight exposure. Expression of CYP27B1 was decreased (P = 0.04) in the kidney but tended to be increased (P=0.06) in the liver following sun exposure. These results suggest limited sun-exposure can efficiently increase serum concentration of vitamin D in growing pigs with varying levels of vitamin sufficiency. The lack of major changes in vitamin synthesizing enzymes suggests the 14 d exposure period did not saturate the capacity of slaughter-weight pigs to synthesize vitamin D.

      PubDate: 2016-11-17T03:35:37Z
       
  • Involvement of salsolinol in suckling-induced oxytocin surge in sheep
    • Abstract: Publication date: Available online 11 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): K. Górski, T. Misztal, E. Marciniak, M.K. Zielińska-Górska, F. Fülöp, K. Romanowicz
      During lactation, the main surge of oxytocin is induced by a suckling stimulus. Previous studies have shown that salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline), a dopamine-derived compound, stimulates both the synthesis and the release of oxytocin in lactating sheep. The objective of the present study was to verify the hypothesis that salsolinol is involved in the mechanism that generates the oxytocin surge that occurs during suckling. Thus, a structural analogue of salsolinol, 1-methyl-3,4-dihydroisoquinoline (1MeDIQ), known to antagonize some of its actions, was infused into the third ventricle of the brain of lactating sheep nursing their offspring. Serial 30-min infusions of 1MeDIQ (4 x 60 μg/60 μl) or vehicle were administered at 30-min intervals from 10.00 to 14.00 h. The experimental period in every ewe consisted of a non-suckling period (10.00 to 12.00 h) and a suckling period (12.00 to 14.00 h). Blood samples were collected every 10 min, to measure plasma oxytocin concentration by radioimmunoassay. In control sheep, oxytocin surges of high amplitude were observed during the suckling period. The oxytocin surges induced by suckling were significantly (P < 0.01) diminished in sheep receiving 1MeDIQ infusions as compared to those that received control infusions. However, no significant effect of 1MeDIQ was observed on basal oxytocin release, before suckling. Furthermore, oxytocin release, as measured by the area under the hormone response curve (AUC), was significantly decreased by the administration of 1MeDIQ during the suckling period. This study shows that elimination of the effect of salsolinol within the central nervous system of lactating sheep attenuates the oxytocin surge induced by suckling. Therefore, salsolinol may be an important factor in the oxytocin-stimulating pathway in lactating mammals.

      PubDate: 2016-11-17T03:35:37Z
       
  • Immunometabolic parameters in overweight dogs during weight loss with or
           without an exercise program
    • Abstract: Publication date: Available online 11 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): A.D. Vitger, B.M. Stallknecht, J.E. Miles, S.L. Hansen, A. Vegge, C.R. Bjørnvad
      The influence of physical activity on metabolic health in overweight dogs is unknown. This study was conducted to evaluate biomarkers of immunometabolic health in relation to changes in physical activity and adiposity. Client-owned overweight dogs participated in a 12-wk intervention based on caloric restriction combined with a training program (fitness & diet (FD) group, n = 8), or caloric restriction alone (diet-only (DO) group, n = 8). Physical activity was monitored by accelerometry. All dogs were fed the same diet and achieved similar weight loss. Fasting blood samples were collected before and after 6 and 12 wk intervention. Insulin resistance was evaluated from plasma insulin and C-peptide as well as homeostasis model assessment (HOMA-IR). Inflammation and dyslipidemia were evaluated from circulating leptin, adiponectin, C-reactive protein (CRP), monocyte chemoattractant factor-1 (MCP-1), interleukin-8 (IL-8) and cholesterol. Accelerometer counts in both groups were high compared to previous reports of physical activity in overweight dogs. No difference in blood parameters was evident between groups, evaluated by linear mixed-effects model (P > 0.05). Within the groups, the following changes were significant by t-test (P < 0.05): Leptin decreased in both groups. Within the FD group, IL-8, MCP-1 and CRP decreased at 6 wk, and IL-8 and cholesterol at 12 wk. Within the DO group, C-peptide and HOMA decreased at 6 wk and C-peptide at 12 wk. We conclude that, for both groups, weight loss resulted in minor indications of improved immunometabolic health, while this level of physical activity did not add further benefits.

      PubDate: 2016-11-17T03:35:37Z
       
  • Oxyntomodulin analog and exendin-4 derivative lower plasma glucose in
           cattle
    • Abstract: Publication date: Available online 2 November 2016
      Source:Domestic Animal Endocrinology
      Author(s): S. ThanThan, Y. Asada, T. Saito, K. Ochiiwa, H. Zhao, S.W. Naing, H. Kuwayama
      The present study was undertaken with the aim of examining whether and how exendin-4 (1-3) fragment, i.e., Ex-4 (1-3) fragment, contributes to the regulation of glucose. An analog of oxyntomodulin (OXM) ([Gly2, Glu3]-OXM), a glucagon analog ([Gly2, Glu3]-glucagon) and two derivatives of Ex-4 (glucandin and [Gly2, Glu3]-glucandin) were synthesized by substituting with Gly2, Glu3 at the N terminuses of OXM and glucagon and/or by attaching Ex-4 (30-39) amide at the C terminus of glucagon. Effects of these peptides on plasma insulin and glucose concentrations were investigated in cattle by conducting three in vivo experiments. In all three experiments, 0.1% BSA-saline was injected as a control. In experiment 1, glucandin (amino acid sequence was glucagon (1-29)-Ex-4 (30-39) amide) and [Gly2, Glu3]-glucandin were injected at the dose rates of 5 μg/kg body weight (BW) in 4-mo-old Holstein steers. Results showed that glucoregulatory effects of glucandin were similar to those of glucagon. [Gly2, Glu3]-glucandin stimulated insulin secretion at 2–10 min and lowered glucose concentrations at 15–75 min. Experiment 2 was carried out to better understand the glucose lowering potency of [Gly2, Glu3]-glucandin, in comparison with Ex-4 and GLP-1, using 4.5-mo-old Holstein steers. [Gly2, Glu3]-glucandin was injected at dose rates of 0.3 μg/kg BW, 1.0 μg/kg BW, 3.2 μg/kg BW and 6.4 μg/kg BW. Ex-4 and GLP-1 were injected at dose rates of 0.3 μg/kg BW. Results showed that the insulinotropic and glucose lowering effects of [Gly2, Glu3]-glucandin were not as potent as for Ex-4 and GLP-1, and the minimum effective dose of [Gly2, Glu3]-glucandin to regulate plasma glucose concentrations was 3.2 μg/kg BW. In experiment 3, [Gly2, Glu3]-OXM, and [Gly2, Glu3]-glucagon were injected at dose rates of 5 μg/kg BW in 5-mo-old Holstein steers. Both [Gly2, Glu3]-OXM and [Gly2, Glu3]-glucagon increased insulin concentration. [Gly2, Glu3]-OXM potently lowered plasma glucose, but [Gly2, Glu3]-glucagon did not change it. In summary, our findings clearly demonstrate that Ex-4 (1-3) fragment contributes to the regulation of glucose. [Gly2, Glu3]-OXM and [Gly2, Glu3]-glucandin are insulinotropic and glucose-lowering peptides. It was of interest that the substitution of the first three amino acids of OXM with Ex-4 (1-3) could reverse the up-regulation of glucose by OXM into down-regulation of glucose. In lowering glycemia, [Gly2, Glu3]-OXM seemed almost as effective as Ex-4, and [Gly2, Glu3]-glucandin was less profound than Ex-4. These findings contributed new insights into the hormonal regulation of glucose in ruminants. The action of [Gly2, Glu3]-OXM and [Gly2, Glu3]-glucandin might provide an advantage in glycemic control of insulin resistance in cattle and humans.

      PubDate: 2016-11-03T00:03:13Z
       
  • Glucocorticoid metabolism in equine follicles and oocytes
    • Abstract: Publication date: Available online 29 October 2016
      Source:Domestic Animal Endocrinology
      Author(s): D. Scarlet, N. Ille, R. Ertl, B.G. Alves, G.D.A. Gastal, S.O. Paiva, M.O. Gastal, E.L. Gastal, C. Aurich
      The objective of this study was to determine whether: (1) systemic and intrafollicular cortisol concentrations in horses are directly related and (2) supraphysiologic levels of glucocorticoids affect in vitro maturation (IVM) rates of oocytes. Specifically, we studied the (1) changes in the intrafollicular cortisol and progesterone in context with granulosa cell gene expression during maturation of equine follicles (from 5 to 9, 10 to 14, 15 to 19, 20 to 24 and ≥ 25 mm in diameter) and (2) effects of cortisol supplementation on IVM rates and gene expression of equine cumulus-oocyte complexes (COCs). For these purposes, follicular fluid, granulosa cells and COCs were collected from 12 mares (mean age 8.6 ± 0.5 yr) by transvaginal aspiration. Cortisol and progesterone concentrations in follicular fluid from follicles ≥ 25 mm were greater (P < .05) than in all other follicle classes, and were positively correlated (r = 0.8; P < .001). Plasma concentrations of cortisol and progesterone did not differ before and after follicle aspiration (P > .05). In granulosa cells, gene expression of NR3C1, HSD11B1, HSD11B2 and CYP21A2 did not differ (P > .05) among different follicle classes. Maturation rates were similar (P > .05) among groups, regardless of the cortisol concentration in the IVM medium. In cumulus cells, mRNA expression of genes involved in glucocorticoid mechanism and apoptosis was either increased (NR3C1 and BCL2) or decreased (HSD11B2) by treatment (P < .01). In oocytes, gene expression of maturation markers (BMP15 and GDF9) was affected (P < .001) by cortisol treatment. This study demonstrates the involvement of glucocorticoids in follicle and oocyte maturation and cortisol modulation by HSD11B2 in equine COCs. Our data provides further information for understanding the normal ovarian endocrine physiology which might in turn also help improve equine-assisted reproduction techniques.

      PubDate: 2016-11-03T00:03:13Z
       
  • An intraovarian mechanism that enhances the effect of an FSH surge on
           recovery of subordinate follicles in heifers
    • Abstract: Publication date: Available online 27 October 2016
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, M.A.R. Siddiqui, J.M. Baldrighi, E.R. Araujo
      The effect of the future dominant follicle (DF), corpus luteum (CL), and side (left ovary, LO; right ovary, RO) on FSH-induced recovery (increase in diameter) of regressing subordinate follicles was studied in heifers. The DF of wave 2 and the largest subordinate follicle remained intact (controls, n = 14 heifers) or were ablated (n = 14 heifers) on a mean of 13 d postovulation when the DF was ∼ 10 mm (hour 0). Concentration of FSH (P < 0.0004) and diameter of subordinate follicles (P < 0.0002) decreased between hours −48 to 0 combined for the control and ablation groups. Thereafter, follicle diameter continued to decrease in the controls. Concentration of FSH increased (P < 0.05) and diameter of subordinates began to increase at hour 12 in the ablation group. The FSH increased to hour 24 and then returned to the hour-0 concentration by hour 72, completing the induced FSH surge. Concentration of LH began to increase at hour 0 in each group and at a similar rate between groups. Follicle recovery in the ablation group was compared among 8 subgroups as defined by the 2 sides and 4 intraovarian patterns (DF−CL pattern, both structures in same ovary; DF pattern, DF alone; CL pattern, CL alone; and devoid pattern, both structures absent). Follicle diameter increased (P < 0.05) between hours 24 and 48, and diameter at hours 24, 48, 72, and 96 involved a 3-way interaction (P < 0.0001) of pattern, side, and hour. The interaction was similar when diameter of the DF that originated from a recovered subordinate was either included or excluded in the analysis. Diameter of subordinate follicles in the ablation group at hour 96 was greater (P < 0.05) in the DF−CL/RO and DF/RO subgroups than in the devoid/LO, devoid/RO, and CL/LO subgroups. The DF−CL/LO and CL/RO subgroups were intermediate. For follicles that decreased in diameter before hour 0, a greater (P < 0.05) percentage increased after hour 0 when the ovary contained a DF and was in the RO (DF−CL/RO and DF/RO subgroups) than for the remaining subgroups even after excluding the DF that originated from a subordinate. Results supported the hypotheses that (1) an induced FSH surge can stimulate the recovery of regressing subordinate follicles and (2) recovery of regressing subordinate follicles by FSH involves an intraovarian mechanism. Our interpretation is that the intraovarian mechanism that enhances the stimulatory effect of FSH on recovery of subordinate follicles was effective only in RO and only when it contained a DF.

      PubDate: 2016-10-27T21:51:18Z
       
  • Timing and duration of nursing from birth affect neonatal porcine uterine
           matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1
    • Abstract: Publication date: Available online 27 October 2016
      Source:Domestic Animal Endocrinology
      Author(s): T.Y. Ho, K.M. Rahman, M.E. Camp, A.A. Wiley, F.F. Bartol, C.A. Bagnell
      Nursing for 2 d from birth supports neonatal porcine uterine and cervical development. However, it is not clear how timing or duration of lactocrine signaling from birth (postnatal day = PND 0) affect development of neonatal female reproductive tract (FRT) tissues. Therefore, studies were conducted to determine effects of age at first nursing and duration of nursing from birth on specific elements of the matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP) system in uterine and cervical tissues at PND 2. When nursing was initiated at 0 h or 30 min of age, targeted proteins, including proMMP9 and MMP9, were detected in uterine and cervical tissues on PND 2, as was uterine TIMP1. However, these proteins were undetectable when nursing was delayed for 12 h, and when gilts were fed milk replacer for 48 h from birth. Increasing the duration of nursing from 30 min to 12 h from birth increased uterine (P < 0.05) and cervical (P < 0.001) MMP9 levels to those observed in gilts nursed for 48 h. Similarly, uterine TIMP1 levels increased with duration of nursing. Uterine MMP2 levels were detectable but unaffected by age at first nursing or duration of nursing from birth. Uterine MMP2 and MMP9 activities, monitored by zymography, reflected immunoblotting data. Results provide evidence for the utility of MMP9 and TIMP1 as markers of age- and lactocrine-sensitive porcine female reproductive tract development.

      PubDate: 2016-10-27T21:51:18Z
       
  • The impact of diet and arginine supplementation on pancreatic mass,
           digestive enzyme activity and insulin-containing cell cluster morphology
           during the estrous cycle in sheep
    • Abstract: Publication date: Available online 21 October 2016
      Source:Domestic Animal Endocrinology
      Author(s): F.E. Keomanivong, A.T. Grazul-Bilska, D.A. Redmer, C.S. Bass, S.L. Kaminski, P.P. Borowicz, J.D. Kirsch, K.C. Swanson
      To determine the effect of feed intake and arginine treatment during different stages of the estrous cycle on pancreatic mass, digestive enzyme activity, and histological measurements, ewes (n = 120) were randomly allocated to one of three dietary groups; control (CON; 2.14 Mcal metabolizable energy/kg), underfed (UF; 0.6 x CON) or overfed (OF; 2 x CON) over 2 yr. Estrus was synchronized using a controlled internal drug release (CIDR) device for 14 d. At CIDR withdrawal, ewes from each dietary group were assigned to one of two treatments; Arg (L-Arg HCl, 155 μmol/kg BW) or Sal (approximately 10 mL Saline). Treatments were administered 3 times daily via jugular catheter and continued until slaughter on d 5 and 10 of the second estrus cycle (early luteal phase, n = 41 and mid-luteal phase, n = 39; year 1) and d 15 of the first estrus cycle (late luteal phase, n = 40; year 2. A blood sample collected from jugular catheters for serum insulin analysis before slaughter. The pancreas was then removed, trimmed of mesentery and fat, weighed, and a sample snap-frozen until enzyme analysis. Additional pancreatic samples were fixed in 10% formalin solution for histological examination of size and distribution of insulin-containing cell clusters. Data were analyzed as a completely randomized design with a factorial arrangement of treatments. Diet, treatment, and diet × treatment were blocked by year and included in the model with initial BW used as a covariate. Day of the estrous cycle was initially included in the model but later removed as no effects (P > 0.10) were observed for any pancreatic variables tested. Overfed ewes had the greatest (P < 0.001) change in BW, final BW, change in BCS, and final BCS. A diet × treatment interaction was observed for change in BW and final BW (P ≤ 0.004). Overfed and CON had increased (P < 0.001) pancreas weight (g) compared to UF ewes. Protein concentration (g/pancreas) was lowest (P < 0.001) in UF ewes while protein content (mg/kg BW) was greater (P = 0.03) in UF than OF ewes. Activity of α-amylase (U/g, kU/pancreas, U/kg of BW, and U/g protein) and trypsin (U/pancreas) was greater (P ≤ 0.003) in OF than UF ewes. Serum insulin was greatest (P < 0.001) in OF ewes. No effects were observed for pancreatic insulin-containing cell clusters. This study demonstrated that plane of nutrition affected several measurements of pancreatic function however, the dosage of Arg used did not influence pancreatic function.

      PubDate: 2016-10-27T21:51:18Z
       
  • Gap junctional connexin mRNA expression in the ovine uterus and placenta:
           Effects of estradiol-17β-treatment, early pregnancy stages and embryo
           origin
    • Authors: M.L. Johnson; D.A. Redmer; L.P. Reynolds; A.T. Grazul-Bilska
      Abstract: Publication date: Available online 11 October 2016
      Source:Domestic Animal Endocrinology
      Author(s): M.L. Johnson, D.A. Redmer, L.P. Reynolds, A.T. Grazul-Bilska
      Gap junctions play a major role in direct, contact-dependent cell-cell communication, and they have been implicated in the regulation of cellular metabolism and the coordination of cellular functions during growth and differentiation of organs and tissues. Gap junctional channels, composed of connexin (Cx) proteins, have been detected and shown to be influenced by hormones (e.g. estrogen and /or progesterone) in uterine and placental tissues in several species. We hypothesized that 1) the mRNA for Cx26, Cx32, Cx37 and Cx43 is expressed in the uterus of ovariectomized sheep treated with estradiol-17β (E2) and in ovine placenta during early pregnancy, 2) E2-treatment of OVX ewes would cause time-specific changes in Cx26, Cx32, Cx37 and/or Cx43 mRNA expression (Experiment 1), and 3) expression of these four Cx would vary across the days of early pregnancy (Experiment 2) and will be affected by embryo origin (i.e., after application of assisted reproductive technologies [ART]; Experiment 3). Thus we collected uterine tissues at 0 to 24 h after E2 treatments (Experiment 1), and placental tissues during days 14 to 30 of early pregnancy after natural (NAT) breeding (Experiment 2) and on day 22 of early pregnancy established after transfer of embryos generated through natural breeding (NAT-ET), in vitro fertilization (IVF) or in vitro activation (IVA, parthenotes; Experiment 3). In Experiment 1, expression of Cx26, Cx37 and Cx43 mRNA increased (P < 0.05) and Cx32 mRNA decreased (P < 0.06) in both caruncular and intercaruncular tissues after E2 treatment. In Experiment 2, during early pregnancy, there were significant changes (P < 0.01) across days in expression of Cx26, Cx37 and Cx43 mRNA in the maternal placenta, accompanied by changes (P < 0.001) in Cx37 and Cx43 mRNA in the fetal placenta. In Experiment 3, in maternal placenta, Cx32 mRNA expression was decreased (P < 0.001) in NAT-ET, IVF and IVA groups compared to the NAT group; but in fetal placenta, Cx32 mRNA expression was increased (P < 0.05) in NAT-ET, IVF and IVF groups, and Cx26 mRNA expression was increased (P < 0.05) in IVA compared to NAT group. These data suggest that Cx26, Cx32, Cx37 and/or Cx43 play specific roles in E2-regulated uterine function and in placental development during early gestation both after natural mating and with application of ART.

      PubDate: 2016-10-13T15:35:51Z
      DOI: 10.1016/j.domaniend.2016.09.004
       
  • Salsolinol – a potential inhibitor of the gonadotropic axis in sheep
           during lactation
    • Authors: E. Marciniak; M. Hasiec; F. Fülöp; T. Misztal
      Abstract: Publication date: Available online 30 September 2016
      Source:Domestic Animal Endocrinology
      Author(s): E. Marciniak, M. Hasiec, F. Fülöp, T. Misztal
      This study tested the hypothesis that salsolinol, a derivative of dopamine, affects gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion in lactating sheep. In the in vivo experiment, the structural analogue of salsolinol, 1-methyl-3,4-dihydroisoquinoline (1-MeDIQ), was infused into the infundibular nucleus/median eminence (IN/ME) of sheep at the 5th wk of lactation to antagonize salsolinol’s action. Simultaneously, cerebrospinal fluid from the third brain ventricle, to determine GnRH concentration, and plasma samples, to measure LH concentration, were collected. In the in vitro experiment, the anterior pituitary (AP) explants from weaned sheep were incubated in culture medium containing two doses of salsolinol, 20 and 100 μg/mL (S20 and S100, respectively). The concentration of LH in the collected media and relative expression of LHβ subunit mRNA in the AP explants were determined. No significant difference was found in mean GnRH concentration in response to 1-MeDIQ infusion, but both mean plasma LH concentration and LH pulse frequency increased significantly (p < 0.001 and p < 0.05, respectively) compared to those in controls. Significantly higher LH concentrations occurred during the 1st (p < 0.001), 2nd (p < 0.001), and 4th (p < 0.05) h of 1-MeDIQ infusion. In the in vitro study, both the S20 and S100 doses of salsolinol caused a significant decrease in the mean medium LH concentration compared to that in the control (p < 0.01 and p < 0.001, respectively). Salsolinol had no effect on the relative LHβ subunit mRNA expression in the incubated tissue. In conclusion, salsolinol is a potential inhibitor of the secretory activity of the gonadotropic axis in lactating sheep, at least at the AP level. Although no significant changes in GnRH release were directly confirmed, an increase in the frequency of LH pulses, does not allow to exclude the central action of salsolinol.

      PubDate: 2016-10-06T12:24:22Z
      DOI: 10.1016/j.domaniend.2016.09.003
       
  • Role of G protein-coupled estrogen receptor-1 in estradiol 17β -induced
           alterations in protein synthesis and protein degradation rates in fused
           bovine satellite cell cultures1
    • Authors: E. Kamanga-Sollo; K.J. Thornton; M.E. White; W.R. Dayton
      Abstract: Publication date: Available online 13 September 2016
      Source:Domestic Animal Endocrinology
      Author(s): E. Kamanga-Sollo, K.J. Thornton, M.E. White, W.R. Dayton
      In feedlot steers, estradiol-17β (E2) and combined E2 and trenbolone acetate (TBA) (a testosterone analog) implants enhance rate and efficiency of muscle growth; and, consequently, these compounds are widely used as growth promoters in several countries. Treatment with E2 stimulates protein synthesis rate and suppresses protein degradation rate in fused bovine satellite cell (BSC) cultures, however the mechanisms involved in these effects are not known with certainty. Although the genomic effects of E2 mediated through the classical estrogen receptors have been characterized, recent studies indicate that binding of E2 to the G protein-coupled estrogen receptor (GPER)-1 mediates non-genomic effects of E2 on cellular function. Our current data show that inhibition of G protein-coupled estrogen receptor (GPER)-1, matrix metalloproteinases 2 and 9 (MMP2/9), or heparin binding epidermal growth factor-like growth factor (hbEGF) suppresses E2-stimulate protein synthesis rate in cultures bovine satellite cells (BSC) (P < 0.001) suggesting that all of these are required in order for E2 to stimulate protein synthesis in these cultures. In contrast, inhibition of GPER-1, MMP2/9, or hbEGF has no effect on the ability of E2 to suppress protein degradation rates in fused BSC cultures indicating that these factors are not required in order for E2 to suppress protein degradation rate in these cells. Furthermore, treatment of fused BSC cultures with E2 increased (P < 0.05) pAKT levels in fused BSC cultures compared to untreated control cultures, indicating that the pAKT pathway may play a role in E2-stimulated effects on cultured BSC. In summary, our current data show that active GPER-1, MMP2/9, and hbEGF are necessary for E2-stimulated protein synthesis but not for E2-simulated suppression of protein degradation in cultured BSC. Additionally, E2-treatment increases pAKT levels in cultured BSC.

      PubDate: 2016-09-16T05:14:08Z
      DOI: 10.1016/j.domaniend.2016.09.002
       
  • Activities for Leptin in Bovine Trophoblast Cells
    • Authors: C.K. Hughes; M.M. Xie; S.R. McCoski; A.D. Ealy
      Abstract: Publication date: Available online 13 September 2016
      Source:Domestic Animal Endocrinology
      Author(s): C.K. Hughes, M.M. Xie, S.R. McCoski, A.D. Ealy
      Leptin is involved in various reproductive processes in humans and rodents, including placental development and function. The specific ways that leptin influences placental development and function in cattle are poorly understood. This work was completed to explore how leptin regulates hormone, cytokine and metalloprotease transcript abundance and cell proliferation in cultured bovine trophoblast cells. In the first set of studies, cells were cultured in the presence of graded recombinant bovine leptin concentrations (0, 10, 50, 250 ng/mL) for 6- or 24-h. Transcript profiles were examined from extracted RNA. Leptin supplementation did not affect abundance of the maternal recognition of pregnancy factor, interferon-tau (IFNT), but leptin increased (P < 0.05) abundance of chorionic somatomammotropin hormone 2 (CSH2; i.e. placental lactogen) at both 6- and 24-h at each concentration tested. At 24-h, the greatest CSH2 abundance (P < 0.05) was detected in cells supplemented with 50 ng/mL leptin. Transcript abundance of the remodeling factor, metalloprotease 2 (MMP2), was greater (P < 0.05) in leptin-treated cells at 24-h but not at 6-h. The 24-h MMP2 response was greatest (P < 0.05) at 250 ng/mL. Transcript abundance for MMP9 was not altered by leptin treatment. In a separate set of studies, cell proliferation assays were completed. Leptin supplementation did not affect CT1 proliferation at any dose tested. In conclusion, leptin supplementation did not affect bovine trophoblast cell proliferation or IFNT expression, but leptin increases CSH2 and MMP2 transcript abundance. Both of these factors are involved with peri- and post-implantation placental development and function, and this implicates leptin as a potential mediator of early placental development and function in cattle.

      PubDate: 2016-09-16T05:14:08Z
      DOI: 10.1016/j.domaniend.2016.09.001
       
  • Moderate high or low maternal protein diets change gene expression but not
           the phenotype of skeletal muscle from porcine fetuses
    • Authors: Kalbe Block; Lefaucheur K.-P. Bellmann Pfuhl Puppe Otten C.C. Metges
      Abstract: Publication date: Available online 16 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): C. Kalbe, D. Lösel, J. Block, L. Lefaucheur, K.-P. Brüssow, O. Bellmann, R. Pfuhl, B. Puppe, W. Otten, C.C. Metges, C. Rehfeldt
      The aim of our study was to characterize the immediate phenotypic and adaptive regulatory responses of fetuses to different in utero conditions reflecting inadequate maternal protein supply during gestation. The gilts fed high (250% above control) or low (50% under control) protein diets isoenergetically adjusted at the expense of carbohydrates from the day of insemination until the fetuses were collected at d 64 or 94 of gestation. We analyzed body composition, histo-morphology, biochemistry, and mRNA expression of fetal skeletal muscle. Both diets had only marginal effects on body composition and muscular cellularity of fetuses including an unchanged total number of myofibers. However, mRNA expression of myogenic regulatory factors (MYOG, MRF4, P ≤ 0.1), IGF system (IGF1, IGF1R, P ≤ 0.05) and myostatin antagonist FST (P = 0.6, in males only) was reduced in the fetal muscle exposed to a maternal low protein diet. As a result of excess protein, MYOD, MYOG, IGF1R and IGFBP5 mRNA expression (P ≤ 0.05) was upregulated in fetal muscle. Differences in muscular mRNA expression indicate in utero regulatory adaptive responses to maternal diet. Modulation of gene expression immediately contributes to the maintenance of an appropriate fetal phenotype that would be similar to that observed in the control fetuses. Moreover, we suggest that the modified gene expression in fetal skeletal muscle can be viewed as the origin of developmental muscular plasticity involved in the concept of fetal programming.

      PubDate: 2016-08-21T22:47:47Z
       
  • A miRNA-target network putatively involved in follicular atresia
    • Authors: F.X. Donadeu; Ioannidis
      Abstract: Publication date: Available online 13 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): F.X. Donadeu, J. Ioannidis
      In a previous microarray study we identified a subset of miRNAs which expression was distinctly higher in atretic than healthy follicles of cattle. In the present study we investigated the involvement of those miRNAs in granulosa and theca cells during atresia. RT-qPCR confirmed that miR-21-5p/-3p, miR-150, miR-409a, miR-142-5p, miR-378, miR-222, miR-155 and miR-199a-5p were expressed at higher levels in atretic than healthy follicles (9-17 mm, classified based on steroidogenic capacity). All miRNAs except miR-21-3p and miR-378 were expressed at higher levels in theca than granulosa cells. The expression of 13 predicted miRNA targets was determined in follicular cells by RT-qPCR, revealing downregulation of HIF1A, ETS1, JAG1, VEGFA and MSH2 in either or both cell types during atresia. Based on increases in miRNA levels simultaneous with decreases in target levels in follicular cells, several predicted miRNA-target interactions were confirmed that are putatively involved in follicular atresia, namely miR-199a-5p/miR-155-HIF1A in granulosa cells, miR-155/miR-222-ETS1 in theca cells, miR-199a-5p-JAG1 in theca cells, miR-199a-5p/miR-150/miR-378-VEGFA in granulosa and theca cells, and miR-155-MSH2 in theca cells. These results offer novel insight on the involvement of miRNAs in follicle development by identifying a miRNA-target network that is putatively involved in follicle atresia.

      PubDate: 2016-08-16T21:47:35Z
       
  • Effect of fish oil on lateral mobility of prostaglandin F2α (FP)
           receptors and spatial distribution of lipid microdomains in bovine luteal
           cell plasma membrane in vitro1
    • Authors: Michele Plewes; Patrick Burns Peter Graham Richard Hyslop George Barisas
      Abstract: Publication date: Available online 12 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): Michele R. Plewes, Patrick D. Burns, Peter E. Graham, Richard M. Hyslop, B. George Barisas
      Lipid microdomains are ordered regions on the plasma membrane of cells, rich in cholesterol and sphingolipids, ranging in size from 10 to 200 nm in diameter. These lipid-ordered domains may serve as platforms to facilitate co-localization of intracellular signaling proteins during agonist-induced signal transduction. It is hypothesized that fish oil will disrupt the lipid microdomains, increasing spatial distribution of these lipid-ordered domains and lateral mobility of the prostaglandin (PG) F2α (FP) receptors in bovine luteal cells. The objectives of this study were to examine the effects of fish oil on 1) the spatial distribution of lipid microdomains, 2) lateral mobility of FP receptors and 3) lateral mobility of FP receptors in the presence of PGF2α on the plasma membrane of bovine luteal cells in vitro. Bovine ovaries were obtained from a local abattoir and corpora lutea were digested using collagenase. In Experiment 1, lipid microdomains were labeled using cholera toxin subunit B Alexa Fluor 555. Domains were detected as distinct patches on the plasma membrane of mixed luteal cells. Fish oil treatment decreased fluorescent intensity in a dose dependent manner (P < 0.01). In Experiment 2, single particle tracking was used to examine the effects of fish oil treatment on lateral mobility of FP receptors. Fish oil treatment increased micro- and macro-diffusion coefficients of FP receptors as compared to control cells (P < 0.05). In addition, compartment diameters of domains were larger and residence times were reduced for receptors in fish oil treated cells (P < 0.05). In Experiment 3, single particle tracking was used to determine the effects of PGF2α on lateral mobility of FP receptors and influence of fish oil treatment. Lateral mobility of receptors was decreased within 5 min following addition of ligand for control cells (P < 0.05). However, lateral mobility of receptors was unaffected by addition of ligand for fish oil treated cells (P > 0.10). The data presented provide strong evidence that fish oil causes a disruption in lipid microdomains and affects lateral mobility of FP receptors in the absence and presence of PGF2α.

      PubDate: 2016-08-12T20:59:21Z
       
  • Prolactin role in the bovine uterus during adenomyosis
    • Authors: B.M. Socha; A.A. A.J. Korzekwa
      Abstract: Publication date: Available online 25 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): M. Łupicka, B.M. Socha, A.A. Szczepańska, A.J. Korzekwa
      Adenomyosis is uterine dysfunction defined as the presence of endometrial glands within the myometrium. It is suggested that adenomyosis is oestrogen-dependent pathology, and prolactin (PRL) also affects its development. In the uterus of ruminants, PRL stimulates gland proliferation and function. We hypothesised that in the bovine uterus, expression of PRL and its receptors (PRLRs) during adenomyosis is disturbed and modulated by oestradiol (E2). Uterine tissues were collected post mortem from cows; epithelial, stromal and myometrial cells were isolated; and cultured and treated with E2. Material was divided into two groups: control (non-adenomyotic) and uteri with adenomyosis. In adenomyotic uterine tissue, PRL and its long-form receptor (lPRLR) protein were increased, as determined by western blotting. Immunohistostaining showed that during adenomyosis, PRL and its receptors are highly expressed in adenomyotic lesions. In cultured myometrial cells, protein expression of PRL and its receptors was increased during adenomyosis. Oestradiol decreased PRLRs protein expression in non-adenomyotic stromal cells and in adenomyotic myometrial cells, and increased PRL secretion by adenomyotic myometrial cells. Moreover, PRL secretion was increased in untreated epithelial and stromal cells during adenomyosis. On the other hand, in stromal cells, PRLRs mRNA and protein expression was decreased, as determined by real-time PCR and western blotting, respectively. Obtained results show that significant changes in PRL and PRLRs expression are observed in uterine tissue and cells during adenomyosis, which were also affected by E2. These data suggest involvement of PRL in adenomyosis development and the link between PRL and E2 actions during the dysfunction in cows.

      PubDate: 2016-08-03T14:10:17Z
       
  • Development of the independent function of fetal thyroid glands in the dog
           in connection with iodothyronine concentrations in pregnant bitches, fetal
           fluids and fetal serum
    • Authors: Balogh
      Abstract: Publication date: Available online 21 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. Thuróczy, J. Szilágyi, L. Müller, L. Balogh
      Thyroxine (T4) and triiodothyronine (T3) concentrations in pregnant and non-pregnant bitches were measured. The allantoic and amniotic fluid samples were collected separately in the third week of pregnancy and fetal blood samples were collected in the fourth week of pregnancy. There was no difference between T4 results in the pregnant and non-pregnant animals, but the measured serum concentrations exceeded the healthy range for normal adults. Serum T4 concentrations were lower in the fetus than in adults (P < 0.01). Fetal T4 concentrations continuously increased and reached 13.38 ± 6.19 nmol/L before birth. The fetal serum T4 concentrations were lower than the T4 concentrations in allantoic and amniotic fluid until the seventh week and the fetal serum T3 concentrations were lower than in fetal fluids throughout the pregnancy (P < 0.01). Maximum T3 concentrations in allantoic and amniotic fluid exceeded the concentrations in the fetal and maternal serum. It is conceivable that the considerable differences between maternal and fetal serum T4 concentrations in healthy animals are explained by the T4 impermeability of the placenta. Extremely high maternal T4 (193.5 nmol/L) in one bitch was associated with T4 concentrations under the detection limit in the fetal fluids and serum suggesting an inhibitory effect. The T4 concentrations in all of the fetal fluids and serum were under the detectable concentration that can be defined by 3.0 nmol/L in that bitch. We have demonstrated that fetal thyroid glands start functioning independently at the same time as thyroid cell formation in the dog, but the overproduction of maternal T4 may have a suppressive effect on fetal iodothyronine production.

      PubDate: 2016-08-03T14:10:17Z
       
  • Expression of progesterone receptor in the porcine uterus and placenta
           throughout gestation: correlation with expression of uteroferrin and
           osteopontin
    • Authors: C.B. Steinhauser; F.W. Bazer R.C. Burghardt G.A. Johnson
      Abstract: Publication date: Available online 15 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): C.B. Steinhauser, F.W. Bazer, R.C. Burghardt, G.A. Johnson
      Progesterone (P4) stimulates production and secretion of histotroph, a mixture of hormones, growth factors, nutrients, and other substances required for growth and development of the conceptus (embryo/fetus and placental membranes). Progesterone acts through the progesterone receptor (PGR); however, there is a gap in our understanding of P4 during pregnancy because PGR have not been localized in the uteri and placentae of pigs beyond day 18. Therefore, we determined endometrial expression of PGR messenger RNA (mRNA) and localized PGR protein in uterine/placental tissues throughout the estrous cycle and through day 85 of pregnancy in pigs. Further, 2 components of histotroph, tartrate-resistant acid phosphatase 5 (ACP5; uteroferrin) and secreted phosphoprotein 1 (SPP1; osteopontin) proteins, were localized in relation to PGR during pregnancy. Endometrial expression of PGR mRNA was highest at day 5 of the estrous cycle, decreased between days 5 and 11 of both the estrous cycle and pregnancy, and then increased between days 11 and 17 of the estrous cycle (P < 0.01), but decreased from days 13 to 40 of pregnancy (P < 0.01). Progesterone receptor protein localized to uterine stroma and myometrium throughout all days of the estrous cycle and pregnancy. PGR were expressed by uterine luminal epithelium (LE) between days 5 and 11 of the estrous cycle and pregnancy, then PGR became undetectable in LE through day 85 of pregnancy. During the estrous cycle, PGR were downregulated in LE between days 11 and 15, but expression returned to LE on day 17. All uterine glandular epithelial (GE) cells expressed PGR from days 5 to 11 of the estrous cycle and pregnancy, but expression decreased in the superficial GE by day 12. Expression of PGR in GE continued to decrease between days 25 and 85 of pregnancy; however, a few glands near the myometrium and in close proximity to areolae maintained expression of PGR protein. Acid phosphatase 5 protein was detected in the GE from days 12 to 85 of gestation and in areolae. Secreted phosphoprotein 1 protein was detected in uterine LE in apposition to interareolar, but not areolar areas of the chorioallantois on all days examined, and in uterine GE between days 35 and 85 of gestation. Interestingly, uterine GE cells adjacent to areolae expressed PGR, but not ACP5 or SPP1, suggesting these are excretory ducts involved in the passage, but not secretion, of histotroph into the areolar lumen and highlighting that P4 does not stimulate histotroph production in epithelial cells that express PGR.

      PubDate: 2016-08-03T14:10:17Z
       
  • Prostaglandin synthesis by the porcine corpus luteum: effect of tumor
           necrosis factor-α
    • Authors: Chang Frandsen; J.E. Gadsby
      Abstract: Publication date: Available online 15 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. Chang, S. Frandsen, J.E. Gadsby
      The porcine corpus luteum (CL) displays delayed sensitivity to PGF-2α (luteolytic sensitivity, [LS]) until days 12 to 13 of cycle. The control of LS is unknown, but it is temporally associated with macrophage (which secrete TNF-α) infiltration into the CL. Other studies showed that TNF-α induces LS in vitro and that prostaglandins may be involved in this mechanism. In experiment 1, PGF-2α and PGE secretion by luteal cells (LCs) was measured on days 4 to 14 of the estrous cycle, and the expression of PTGFS/AKR1B1 and PTGES/mPGES-1, by Western blot, before (day 7) vs after (day 13) the onset of LS. Results showed that the PGF-2α:PGE ratio increased significantly (P < 0.05) from day 4 to 13–14, and PTGFS/AKR1B1 and PTGES/mPGES-1 were significantly increased (P < 0.05) on day 13 (vs day 7). In experiment 2, LCs were collected from porcine CL at early (∼days 4–6) or mid (∼days 7–12) stages of the estrous cycle and cultured with 0, 0.1, 1, or 10-ng/mL TNF-α. Results showed that TNF-α significantly increased (P < 0.05) messenger RNA (mRNA) expression of cyclooxygenase (COX)-2 and mPGES-1 but not AKR1B1. TNF-α had no significant effects on AKR1B1 or mPGES protein abundance. TNF-α significantly increased (P < 0.05) PGE-2 but had no effect on PGF2αs secretion or on the PGF2α:PGE2 ratio. In conclusion, although TNF-α increased COX2 and mPGES-1 mRNA, and PGE-2 secretion in vitro, it did not increase the PGF2α:PGE2 ratio. Studies are currently directed toward exploring other pathways (eg, FP receptor signaling) by which TNF-α induces LS in the porcine CL.

      PubDate: 2016-08-03T14:10:17Z
       
  • Characteristics, tissue-specific expression, and hormonal regulation of
           expression of tyrosine aminotransferase in the avian female reproductive
           tract
    • Authors: Lim Song
      Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): W. Lim, G. Song
      Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine to p-hydroxyphenylpyruvate. Accumulation of tyrosine in the body due to a genetic mutation in the TAT gene causes tyrosomia type II in humans. The TAT gene is regarded as a model for studying steroid-inducible factors regulating a variety of biological functions of TAT. However, little is known of the effects of estrogen on the expression of the TAT gene in chickens. Therefore, in the present study, we identified expression of the avian TAT gene in various organs. The results showed the TAT was detected predominantly in the liver and reproductive organs including testis, oviduct, and ovary. Specifically, TAT mRNA was expressed abundantly in the glandular and luminal epithelia of the oviducts in response to endogenous and exogenous estrogens which also induce dramatic morphological changes in the oviduct of chickens. In addition, target microRNAs of TAT (miR-1460, miR-1626-3p, miR-1690-5p, and miR-7442-3p) were found to modulate expression of the TAT gene. Especially, miR-1690-5p influenced TAT gene transcription by binding directly to its 3′-UTR region. Moreover, the expression of TAT was abundant in glandular epithelia of cancerous but not normal ovaries from laying hens. Taken together, our findings suggest that TAT plays an important role in the cytodifferentiation of oviducts in response to estrogen and in the progression of ovarian cancer in chickens.

      PubDate: 2016-06-18T18:51:23Z
       
 
 
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