for Journals by Title or ISSN
for Articles by Keywords

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2        [Sort by number of followers]   [Restore default list]

  Subjects -> VETERINARY SCIENCE (Total: 216 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 2)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 3)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 9)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 16)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 6)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 12)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 32)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 189)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 3)
Animal Nutrition     Open Access   (Followers: 17)
Animal Reproduction     Open Access   (Followers: 3)
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 10)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 5)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 9)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
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: 3)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 5)
Australian Veterinary Journal     Hybrid Journal   (Followers: 23)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 8)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access   (Followers: 2)
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 2)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 14)
Brazilian Journal of Veterinary Medicine     Open Access  
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Open Access   (Followers: 1)
Buletin Veteriner Udayana     Open Access   (Followers: 3)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 2)
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: 12)
Case Reports in Veterinary Medicine     Open Access   (Followers: 7)
Ciência Animal Brasileira     Open Access   (Followers: 1)
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access   (Followers: 3)
Companion Animal     Full-text available via subscription   (Followers: 10)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 7)
Equine Health     Full-text available via subscription   (Followers: 4)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 17)
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: 3)
GISAP : Biology, Veterinary Medicine and Agricultural Sciences     Open Access  
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 9)
ILAR Journal     Hybrid Journal   (Followers: 2)
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: 5)
Indonesia Medicus Veterinus     Open Access   (Followers: 1)
Intas Polivet     Full-text available via subscription   (Followers: 3)
International Journal of Tropical Veterinary and Biomedical Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Irish Veterinary Journal     Open Access   (Followers: 7)
Japanese Journal of Veterinary Research     Open Access   (Followers: 1)
Journal of Veterinary Science & Technology     Open Access   (Followers: 9)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 6)
Journal of Advanced Veterinary Research     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 6)
Journal of Animal Science and Technology     Open Access   (Followers: 2)
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 8)
Journal of Buffalo Science     Hybrid Journal   (Followers: 2)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 14)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 6)
Journal of Feline Medicine and Surgery Open Reports     Open Access   (Followers: 2)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 5)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 17)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 44)
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: 5)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 10)
Journal of Veterinary Dentistry     Full-text available via subscription   (Followers: 1)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 9)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 19)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 28)
Journal of Veterinary Medical Education     Partially Free   (Followers: 13)
Journal of Veterinary Medicine     Open Access   (Followers: 12)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 9)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 8)
Journal of Veterinary Research     Open Access   (Followers: 3)
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 5)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 7)
Jurnal Agripet     Open Access   (Followers: 1)
Jurnal Ilmu dan Kesehatan Hewan (Veterinary Science and Medicine Journal)     Open Access   (Followers: 1)
Jurnal Medika Veterinaria     Open Access  
Jurnal Sain Veteriner     Open Access  
Jurnal Veteriner     Open Access   (Followers: 1)
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: 2)
Medical Mycology     Open Access   (Followers: 4)
Medical Mycology Case Reports     Open Access  
Medicina Veterinária (UFRPE)     Open Access   (Followers: 1)
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 16)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 4)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 2)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 7)
Open Access Animal Physiology     Open Access   (Followers: 5)
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: 12)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 12)
Research Journal of Veterinary Sciences     Open Access   (Followers: 10)
Revista Acadêmica : Ciência Animal     Open Access  
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access   (Followers: 1)
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Reprodução Animal     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
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 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   (Followers: 1)
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  
Science and Animal Health     Open Access  
Scientific Journal of Animal Science     Open Access   (Followers: 6)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 3)
South African Journal of Wildlife Research     Open Access   (Followers: 2)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 2)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 3)
The Professional Animal Scientist     Hybrid Journal  
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: 4)
Trends in Parasitology     Full-text available via subscription   (Followers: 11)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinaria     Open Access   (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: 13)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 12)
Veterinary and Comparative Orthopaedics and Traumatology (VCOT)     Hybrid Journal   (Followers: 6)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 10)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 14)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 9)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 8)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 24)
Veterinary Dermatology     Hybrid Journal   (Followers: 9)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 12)
Veterinary Journal     Hybrid Journal   (Followers: 19)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 4)
Veterinary Medicine and Science     Open Access   (Followers: 2)
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)

        1 2        [Sort by number of followers]   [Restore default list]

Journal Cover Domestic Animal Endocrinology
  [SJR: 0.751]   [H-I: 59]   [7 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0739-7240
   Published by Elsevier Homepage  [3177 journals]
  • Expression of membrane progestin receptors (mPRs) in the bovine corpus
           luteum during the estrous cycle and first trimester of pregnancy
    • Abstract: Publication date: April 2018
      Source:Domestic Animal Endocrinology, Volume 63
      Author(s): Magdalena K. Kowalik, Robert Rekawiecki, Jan Kotwica
      Progesterone (P4) affects luteal cell function through nuclear P4 receptors and via nongenomic mechanisms, presumably involving membrane P4 receptors. There are 2 types of these receptors: progesterone receptor membrane component (PGRMC) and membrane progestin receptor (mPR), including mPR alpha (mPRα), beta (mPRβ), and gamma (mPRγ), which belong to the progestin and adipoQ receptor family (PAQR 7, 8, and 5, respectively). The aim of this study was to evaluate mRNA expression, protein expression, and localization of mPRα, mPRβ, and mPRγ in the bovine corpus luteum (CL) on days 2–5, 6–10, 11–16, and 17–20 of the estrous cycle as well as on weeks 3–5, 6–8, and 9–12 of pregnancy (n = 5/each period). The highest mPRα mRNA expression was found on days 11–16 (P < 0.05) and 17–20 (P < 0.001) of the estrous cycle compared with other stages of the estrous cycle and pregnancy. The mPRβ mRNA level was highest (P < 0.01) on days 11–20 of the estrous cycle and in all stages of pregnancy. mPRγ mRNA expression was highest (P < 0.001) on days 17–20 of the estrous cycle and also during weeks 9–12 of pregnancy compared with the other stages of the estrous cycle and pregnancy. Only the mPRα protein was changed during the estrous cycle; there were no significant differences in protein expression of mPRβ and mPRγ during the estrous cycle and pregnancy. Immunostaining for the mPRα, mPRβ, and mPRγ proteins was detectable in the CL sections at all stages of the estrous cycle and pregnancy. Strong positive staining was observed in small luteal cells; this reaction was less evident in large luteal cells. All proteins were also localized in endothelial cells of blood vessels. The obtained data indicate variable expression of mPRα, mPRβ, and mPRγ in bovine CL during the estrous cycle and first trimester of pregnancy and suggest that P4 may be involved in the regulation of CL function via these membrane receptors during both the estrous cycle and pregnancy.

      PubDate: 2018-02-26T02:52:12Z
  • Hair cortisol and progesterone detection in dairy cattle: interrelation
           with physiological status and milk production
    • Abstract: Publication date: Available online 19 February 2018
      Source:Domestic Animal Endocrinology
      Author(s): O. Tallo-Parra, A. Carbajal, L. Monclús, X. Manteca, M. Lopez-Bejar
      Hair cortisol concentrations (HCC) and hair progesterone concentrations (HPC) allow monitoring long-term retrospective steroid levels. However, there are still gaps in the knowledge of the mechanisms of steroids deposition in hair and its potential application in dairy cattle research. This study aimed to evaluate the potential uses of hair steroid determinations by studying the interrelations between HCC, HPC, physiological data from cows and their milk production and quality. Cortisol and progesterone concentrations were analysed in hair from 101 milking Holstein-Friesian cows in a commercial farm. Physiological data were obtained from the 60 d previous to hair collection. Moreover, productive data from the month when hair was collected and the previous one were also obtained as well as at 124 d after hair sampling. Significant but weak correlations were found between HCC and HPC (r = 0.25, P < 0.0001) and between HPC and age (r = 0.06, P = 0.0133). High HCC were associated to low milk yields from the two previous months to hair sampling (P = 0.0396) and during the whole lactation (P < 0.0001). High HCC were also related to high somatic cell count (P = 0.0241). No effect of HCC on fat or protein content was detected. No significant correlations were detected between hair steroid concentrations and pregnancy status, days of gestation, parturition category (primiparous vs. multiparous), number of lactations or days in milk. The relationship between physiological variables and HCC or HPC could depend on the duration of the time period over which hair accumulated hormones. Steroid concentrations in hair present high variability between individuals but are a potential tool for dairy cattle welfare and production research by providing a useful and practical tool for long-term steroid monitoring.

      PubDate: 2018-02-26T02:52:12Z
  • Orexin A but not orexin B regulates lipid metabolism and leptin secretion
           in isolated porcine adipocytes
    • Abstract: Publication date: Available online 4 January 2018
      Source:Domestic Animal Endocrinology
      Author(s): E. Pruszynska-Oszmalek, P.A. Kolodziejski, P. Kaczmarek, M. Sassek, D. Szczepankiewicz, R. Mikula, K.W. Nowak
      It is well known that orexins are involved in the metabolism and endocrine function of rodent adipocytes, but there are no data on other animal species, including pigs. Therefore, in this study, we tested the hypothesis that OxA and OxB modulate the metabolism and endocrine functions of isolated porcine adipocytes and adipose tissue explants. Moreover, we characterized the possible mechanism of OxA action in porcine adipocytes. According to the results, both orexin receptor 1 and orexin receptor 2 were expressed in the porcine adipose tissue. We found that OxA suppressed the release of glycerol from porcine adipocytes both in the absence (basal lipolysis; P<0.05) and in the presence (stimulated lipolysis; P<0.05) of isoproterenol. OxA increased basal and insulin-stimulated glucose uptake (P<0.05), as well as it enhanced the rate of glucose incorporation into lipids with insulin (stimulated lipogenesis; P<0.01) or without insulin (basal; P<0.05). We have also shown that OxA stimulated the mRNA expression of glucose transporter 4 (GLUT4) (P<0.05) and its translocation into the plasma membrane (P<0.01). Moreover, OxA upregulated the mRNA expression of leptin in isolated porcine adipocytes (P<0.05) and increased the secretion of leptin (P<0.05). We have also demonstrated one of the possible mechanisms of OxA action in adipocytes. In the presence of ERK1/2 inhibitor, the effect of OxA was not detectable in porcine adipocytes, which indicates that this peptide increased cell viability via ERK1/2 pathway (P<0.05). However, OxB did not show any effect on the metabolism and endocrine functions of porcine adipocytes. In summary, we have shown for the first time that OxA has a significant impact on the intensity of lipolysis, glucose uptake, lipogenesis, as well as on the expression and secretion of leptin. Therefore, we conclude that OxA but not OxB regulates lipid metabolism in porcine adipose tissue and that this regulation is partly mediated via ERK1/2 pathway. The action of orexins should be further explored in order to better understand their role in the regulation of adiposity in pigs.

      PubDate: 2018-01-05T10:50:27Z
  • Transcriptome profiling of bovine ovarian theca cells treated with
           fibroblast growth factor 9
    • Abstract: Publication date: Available online 4 January 2018
      Source:Domestic Animal Endocrinology
      Author(s): Luís F. Schütz, Robert E. Hurst, Nicole B. Schreiber, Leon J. Spicer
      We reported previously that fibroblast growth factor 9 (FGF9) acts as an anti-differentiation factor, stimulating proliferation of granulosa (GC) and theca (TC) cells while suppressing hormone-induced steroidogenesis of these cells. How FGF9 acts to simultaneously suppress steroidogenesis and stimulate proliferation remains to be fully elucidated. Thus, this study was undertaken to clarify the effects of FGF9 on the TC transcriptome. Ovaries were obtained from beef heifers at a local abattoir, TC were isolated from large antral follicles, and cultured with or without 30 ng/mL of FGF9 for 24 h in the presence of LH and IGF-1. Following treatment, total RNA was extracted from TC and processed for microarray using Affymetrix GeneChip Bovine Genome Arrays (n = 4/group). Transcriptome analysis comparing FGF9-treated TC with control TC using 1.3-fold cut-off and a P < 0.05 significance level identified 355 differentially expressed transcripts, with 164 elements up-regulated and 191 elements down-regulated by FGF9. The Ingenuity Pathway Analysis (IPA) was utilized to investigate how FGF9 treatment affects molecular pathways, biological functions, and the connection between molecules in bovine TC. The IPA software identified 346 pathways in response to FGF9 in TC involved in several biological functions, and unveiled interesting relationships among genes related to cell proliferation (e.g., CCND1, FZD5 and MYB), antioxidation/cytoprotection (e.g., HMOX1 and NQO1) and steroidogenesis (e.g., CYP11A1 and STAR). Overall, genes, pathways, and networks identified in this study painted a picture of how FGF9 may regulate folliculogenesis, providing novel candidate genes for further investigation of FGF9 functions in ovarian follicular development.

      PubDate: 2018-01-05T10:50:27Z
  • Effect of fish oil on agonist-induced receptor internalization of the
           prostaglandin F2α receptor and cell signaling in bovine luteal cells in
    • Abstract: Publication date: Available online 12 December 2017
      Source:Domestic Animal Endocrinology
      Author(s): M.R. Plewes, P.D. Burns
      Many receptors span the plasma membrane allowing for signal transduction, converting extracellular signals into intracellular signals. Following ligand-induced activation, membrane-bound receptors are taken into endocytic vesicles, where they are targeted for degradation or recycled back to the plasma membrane. The objectives of the current study were to determine the influence of fish oil on (1) prostaglandin (PG) F2α–induced receptor internalization and trafficking of the PGF2α (FP) receptor, (2) cytoskeletal structural integrity, and (3) PGF2α-induced mitogen-activated protein kinase (MAPK) signaling in bovine luteal cells. Bovine ovaries were obtained from a local abattoir and corpora lutea (CL; n = 4–6) were digested using collagenase. For all experiments, cells were incubated in either BSA or fish oil-supplemented media for 72 h to allow incorporation of omega-3 fatty acids into biological membranes. Confocal microscopy was used to determine the influence of fish oil on PGF2α–induced receptor internalization and trafficking of the FP receptor and cytoskeletal structural integrity. Additionally, western blotting was used to determine the effects of fish oil on PGF2α-induced MAPK signaling in bovine luteal cells. Results from the present study demonstrate that fish oil disrupts the colocalization of Gαq with both caveolae microdomains and FP receptor as well as PGF2α -induced MAPK signaling. This disruption of the FP receptor with the G-protein alpha subunit may be one mechanism by which a MAPK signaling is diminished following the addition of PGF2α. Furthermore, fish oil disrupts FP receptor internalization and endosomal protein trafficking without detectable changes in the cytoskeleton.

      PubDate: 2017-12-12T14:08:02Z
  • The oral glucose test predicts laminitis risk in ponies fed a diet high in
           nonstructural carbohydrates
    • Abstract: Publication date: April 2018
      Source:Domestic Animal Endocrinology, Volume 63
      Author(s): A.D. Meier, M.A. de Laat, D.B. Reiche, C.C. Pollitt, D.M. Walsh, J.M. McGree, M.N. Sillence
      The aim of this study was to investigate the relationship between laminitis development in ponies and insulin/glucose concentrations in response to the oral glucose test (OGT) and a dietary challenge high in nonstructural carbohydrates (NSCs). After undergoing an OGT (1 g dextrose/kg BW in feed), 37 ponies with 2-h serum insulin concentrations ranging from 22 to 1,133 μIU/mL were subjected to a diet challenge period (DCP), consuming 12 g NSC/kg BW/d for up to 18 d. Insulin and glucose responses were measured on day 2 of the DCP. Clinical laminitis was diagnosed by blinded experts and confirmed radiographically. Basal ACTH levels and clinical signs were assessed to investigate concurrent putative pituitary pars intermedia dysfunction (PPID). The diet induced Obel grade 1 or 2 laminitis in 14 ponies (38%). The ponies that developed laminitis had higher maximum concentrations of blood glucose (P = 0.04) and serum insulin (P = 0.02) in response to the diet. The geometric mean (95% CI) blood glucose concentration for laminitis cases was 14.9 (12.9–17.2) mM, compared to 10.7 (9.2–12.5) mM for ponies who did not develop laminitis. Similarly, the geometric mean (95% CI) for serum insulin was 396 (301–520) μIU/mL for laminitis cases, compared to 216 (148–316) μIU/mL for ponies who did not develop laminitis. Laminitis incidence was likewise associated with insulin concentrations measured during the OGT. Laminitis occurred at frequencies of 0% (0/7) if postdextrose insulin (μIU/mL) was <50; 35% (8/23) if insulin was 50 to 195; and 86% (6/7) if insulin was >195 μIU/mL. Basal ACTH concentrations were above seasonally accepted reference ranges in 16/37 ponies, and 8 of these animals (50%) developed laminitis. This included all 5 ponies in the study that had clinical signs of PPID (100%). In contrast, hyperinsulinemia and laminitis occurred in only 3/11 ponies (27%) with elevated ACTH concentrations and no clinical signs of PPID (P = 0.009). Thus, laminitis occurrence was associated with higher glucose and insulin responses to both the OGT and challenge diet, and the frequency of laminitis can be predicted based on insulin and glucose hyperresponsiveness to these oral carbohydrate challenges.

      PubDate: 2017-11-25T03:56:04Z
  • Steroidogenic Factor-1 Inverse Agonists as a Treatment Option for Canine
           Hypercortisolism: In Vitro Study
    • Abstract: Publication date: Available online 21 November 2017
      Source:Domestic Animal Endocrinology
      Author(s): K. Sanders, J.A. Mol, A. Slob, H.S. Kooistra, S. Galac
      Hypercortisolism is one of the most commonly diagnosed endocrinopathies in dogs, and new targeted medical treatment options are desirable. Steroidogenic factor-1 (SF-1), an orphan nuclear hormone receptor, is a key regulator of adrenal steroidogenesis, development and growth. In pituitary-dependent hypercortisolism, high plasma ACTH concentrations increase the transcriptional activity of SF-1. In adrenal-dependent hypercortisolism, SF-1 expression is significantly greater in dogs with recurrence after adrenalectomy than in those without recurrence. Inhibition of SF-1 could therefore be an interesting treatment option in canine spontaneous hypercortisolism. We determined the effects of three SF-1 inverse agonists, compounds IsoQ A, #31 and #32, on cortisol production, on the mRNA expression of steroidogenic enzymes and steroidogenic factors, and on cell viability, in primary adrenocortical cell cultures of eight normal adrenal glands and of three cortisol-secreting adrenocortical tumors. To mimic pituitary-dependent hypercortisolism, the normal adrenocortical cell cultures were stimulated with ACTH. The results show that only compound #31 inhibited cortisol production and SF-1 target gene expression in non-ACTH-stimulated and ACTH-stimulated normal adrenocortical cells, but did not affect cell viability. In the adrenocortical tumor cell cultures, the effects of #31 on cortisol production and target gene expression were variable, possibly caused by a difference in the SF-1 mRNA expressions of the primary tumors. In conclusion, inhibition of SF-1 activity shows much promise as a future treatment for canine hypercortisolism.

      PubDate: 2017-11-25T03:56:04Z
  • Concentrations of a PGF2α metabolite during pregnancy on the days that
           luteolysis occurs in nonbred heifers
    • Abstract: Publication date: Available online 3 November 2017
      Source:Domestic Animal Endocrinology
      Author(s): F.L.V. Pinaffi, E.R. Araujo, O.J. Ginther
      Concentrations of a metabolite of PGF2α (PGFM) were compared between nonbred (n = 6) and pregnant (n = 8) heifers on days 16, 17, and 18 postovulation. On each day, an 8-h session of hourly blood sampling was done. Averaged over the 8-h sessions, mean concentration of PGFM was less (P < 0.0009) in the pregnant group (45.2 ± 3.2 pg/mL) than that in the nonbred group (65.6 ± 7.9 pg/mL), but the minimal concentration per session was not significantly different between groups. Pulses of PGFM (coefficient of variance identified) were similar in frequency between groups but were less (P < 0.03) prominent at the peak in the pregnant group (60.0 ± 5.3 pg/mL) than that in the nonbred group (92.8 ± 10.7 pg/mL). These results indicated similarity between groups in frequency and initial development of a PGFM pulse but without later development and a reduction in prominence in the pregnant group. The progesterone response to a PGFM pulse of similar prominence was made before the beginning of luteolysis in individuals in the nonbred group and during the hourly sessions on days 16 to 18 in the pregnant group. Progesterone concentration in the nonbred group decreased (P < 0.05) during 2 h before the PGFM peak (8.8 ± 1.6 to 5.6 ± 1.0 ng/mL) and rebounded (P < 0.05) completely during the 2 h after the peak (5.6 ± 1.0 to 9.6 ± 2.2 ng/mL). A transient progesterone decrease during a similar PGFM pulse and similar initial progesterone concentration did not occur in the pregnant group. Results supported the hypotheses that (1) pregnant heifers have identifiable but less prominent PGFM pulses during the days that luteolysis occurs in nonbred heifers and (2) the CL locally resists the luteolytic effect of PGF2α in pregnant heifers before the days of onset of luteolysis in nonbred heifers.

      PubDate: 2017-11-08T01:43:12Z
  • Role of luteal biosynthesis of prostaglandin F2α on function and
           structure of the corpus luteum during luteolysis in heifers
    • Abstract: Publication date: Available online 1 November 2017
      Source:Domestic Animal Endocrinology
      Author(s): F.L.V. Pinaffi, E.R. Araujo, O.J. Ginther
      The role of endogenous prostaglandin F2α (PGF) in the induction of luteolysis by exogenous PGF was studied by simultaneous inhibition of endogenous PGF with flunixin meglumine (FM). Groups were controls (n = 8), PGF treated (n = 8), and FM+PGF treated (n = 9). Treatments were given 10 days postovulation at hours 0, 8, and 16. The protocol was based on (1) the assumption that luteolytic characteristics of exogenous PGF would be altered if the synthesis of endogenous PGF is simultaneously inhibited and (2) reports that luteolysis involves a direct effect of uterine PGF on large luteal cells followed by an effect of the large cells on the small cells. At hour 48, progesterone concentration was greater in the controls (7.6 ± 0.8 ng/mL) than in the FM+PGF group (3.0 ± 0.5 ng/mL) and lower in the PGF group (0.7 ± 0.3 ng/mL) than in the FM+PGF group (interaction, P < 0.0001). The effects of each of the three groups on percentage change in CL volume were similar to the effects on progesterone. At hour 48, percentage of CL tissue with color-Doppler signals of blood flow was similar between the controls (56.2 ± 3.8%) and FM+PGF group (50.0 ± 6.4%) and lowest in the PGF group (15.6 ± 7.2%) (interaction, P < 0.0001). A resurgence in progesterone concentration began at hours 24 or 48 in 6 of 9 heifers in the FM+PGF group compared to 0 of 8 heifers in each of the other groups (P < 0.007). The progesterone resurgence in the FM+PGF group was associated with the maintenance of percentage of CL tissue with blood-flow signals. The experimental hypothesis that an inhibitor of endogenous PGF reduces the luteolytic response to exogenous PGF was supported.

      PubDate: 2017-11-08T01:43:12Z
  • Effect of dietary carbohydrates and time of year on adrenocorticotropic
           hormone (ACTH) and cortisol concentrations in adult and aged horses
    • Abstract: Publication date: Available online 1 November 2017
      Source:Domestic Animal Endocrinology
      Author(s): S.I. Jacob, R.J. Geor, P.S.D. Weber, P.A. Harris, M.E. McCue
      Diagnosis of equine pituitary pars intermedia dysfunction (PPID) remains a challenge as multiple factors (stress, exercise, time of year) influence adrenocorticotropic hormone (ACTH) and cortisol concentrations. To assess endocrine status in a study designed to evaluate the effects of age and diet on glucose and insulin dynamics, we performed thyrotropin releasing hormone (TRH) stimulation tests and overnight dexamethasone suppression tests in March, May, August, and October on sixteen healthy Thoroughbred and Standardbred mares and geldings. Horses were grouped by age: adult (mean ± SD; 8.8 ± 2.9 yr; n = 8) and aged (20.6 ± 2.1 yr; n = 8). None of the horses showed clinical signs (hypertrichosis, regional adiposity, skeletal muscle atrophy, lethargy) of pituitary pars intermedia dysfunction. Horses were randomly assigned to groups of four, blocked for age, and fed grass hay plus four isocaloric concentrate diets (control, starch-rich, fiber-rich, sugar-rich) using a balanced Latin square design. Data were analyzed using a multivariable linear mixed regression model. Baseline ACTH was significantly higher in aged horses (mean ± SEM; 60.0 ± 10.7 pg/mL) adapted to the starch-rich diet compared to adult horses (15.7 ± 12.0 pg/mL) on the same diet (P = 0.017). After controlling for age and diet, baseline ACTH concentrations were significantly increased in October (57.7 ± 7.1 pg/mL) compared to March (13.2 ± 7.1 pg/mL; P < 0.001), May (12.4 ± 7.1 pg/mL; P < 0.001) and August (24.2 ± 7.1 pg/mL; P < 0.001) while post-TRH ACTH was higher in August (376.6 ± 57.6 pg/mL) and October (370.9 ± 57.5 pg/mL) compared to March (101.9 ± 57.3 pg/mL; P < 0.001) and May (74.5 ± 57.1 pg/mL; P < 0.001). Aged horses had significantly higher post-dexamethasone cortisol on the starch-rich diet (0.6 ± 0.1μg/dL) compared to the sugar-rich diet (0.2 ± 0.1 μg/dL; P = 0.021). Post-dexamethasone cortisol was significantly higher in October (0.6 ± 0.1 μg/dL) compared to March (0.3 ± 0.1 μg/dL; P = 0.005), May (0.2 ± 0.1 μg/dL; P < 0.001) and August (0.3 ± 0.1 μg/dL; P = 0.004). Breed did not influence ACTH or cortisol measurements. In conclusion, in addition to age and time of year, diet is a potential confounder as animals on a starch-rich diet may be incorrectly diagnosed with pituitary pars intermedia dysfunction.

      PubDate: 2017-11-08T01:43:12Z
  • Evaluation of oral sugar test response for detection of equine metabolic
           syndrome in obese Crioulo horses
    • Abstract: Publication date: Available online 31 October 2017
      Source:Domestic Animal Endocrinology
      Author(s): C. Cantarelli, S.L. Dau, S. Stefanello, M.S. Azevedo, G.R. De Bastiani, H.E. Palma, K.E. Brass, F.D. De La Côrte
      Due to the high prevalence of obesity in Crioulo horses, information allowing early diagnosis of equine metabolic syndrome (EMS) and prevention of the associated laminitis is of great value. The aim of this study was to evaluate the occurrence of EMS and the response to an oral sugar test (OST) in obese Crioulo horses. Twenty-two Crioulo horses were allocated into three groups according to their body condition score (BCS out of 9) and presence or absence of laminitis as follows: CON (6/22), BCS < 7; OB (8/22), BCS ≥ 7; and LAM (8/22), BCS ≥ 7 with clinical and/or radiographic signs of laminitis. A complete clinical history was obtained, followed by a physical examination, morphometric measurements, radiographic evaluation of front feet and ultrasonography measurements of subcutaneous body fat. For the OST, animals were fasted overnight and blood samples were collected for glucose and insulin concentration before and after sugar administration. Morphometric and metabolic differences (P < 0.05) were observed between CON animals and obese ones, with horses from the LAM group presenting the highest morphometric measurements and insulin plasma concentrations. A delayed peak glucose response for OST was observed in the majority of obese animals, indicating that sampling between 60 and 90 min after sugar administration without glycemic curve follow-up, as previously used for hyperinsulinism detection, can be inadequate. The observed delay in the return to glucose baseline levels, combined with high insulin levels, supports the diagnosis of insulin dysregulation. These results indicate that there are clear obesity-related differences in the glucose and insulin responses of Crioulo horses to an oral sugar test.

      PubDate: 2017-10-31T23:58:12Z
  • In the ovine pituitary, CXCR4 is localized in gonadotropes and
           somatotropes and increases with elevated serum progesterone
    • Abstract: Publication date: Available online 28 October 2017
      Source:Domestic Animal Endocrinology
      Author(s): N.S. Sanchez, K.E. Quinn, A.K. Ashley, R.L. Ashley
      The pituitary is the central endocrine regulator of reproduction and in addition to various hormones regulating its actions, other molecules, such as chemokines, influence pituitary physiology as well. Despite reports over two decades ago that chemokines regulate the pituitary, much of the basic biology discerning chemokine action in the pituitary is unclear. A small number of chemokines and their receptors have been localized to the pituitary, yet chemokine ligand 12 (CXCL12) and its receptor, CXCR4 have received the most attention as both are increased in human pituitary adenomas. This chemokine duo was also reported in normal human and rat pituitary; suggestive of a functional role and that this chemokine axis might function in pituitaries from other mammalian species. To date, reports of CXCL12 and CXCR4 in pituitary from livestock are lacking and research on pituitary during pregnancy in any mammalian species is limited. Moreover, progesterone regulates CXCR4 expression in a tissue dependent manner, but whether differing concentrations of progesterone reaching the pituitary modulate CXCL12 or CXCR4 is not known. To address these gaps, our first objective was to determine if CXCL12 and CXCR4 expression and protein abundance differ in sheep pituitary during early gestation (days 20, 25, and 30 of gestation) compared to non-pregnant ewes. The second objective was to determine if CXCL12 or CXCR4 production was altered in the ovine pituitary when circulating progesterone concentrations are elevated. Expression of CXCL12 mRNA decreased on day 20 of gestation compared to non-pregnant ewes; CXCL12 protein was similar across all days tested. In non-pregnant and pregnant ewes, CXCR4 was localized to somatotropes and gonadotropes on all days tested. Abundance of CXCR4 increased in pituitary tissue from pregnant ewes with elevated circulating progesterone compared to pregnant ewes with normal circulating progesterone concentrations (control). The current study details CXCL12 and CXCR4 in normal ovine pituitary and reveals gonadotropes and somatotropes may be regulated by CXCL12/CXCR4, underscoring this signaling axis as a potential new class of modulator in endocrine functions.

      PubDate: 2017-10-31T23:58:12Z
  • The effect of diet, adiposity and weight loss on the secretion of incretin
           hormones in cats
    • Abstract: Publication date: Available online 20 October 2017
      Source:Domestic Animal Endocrinology
      Author(s): K.E. McCool, A.J. Rudinsky, V.J. Parker, C.O. Herbert, C. Gilor
      Degree of adiposity and dietary macronutrient composition affect incretin hormone secretion in humans and mice, but little is known about their effect in cats. In this study, seven overweight cats were fed a maintenance diet (MD) for at least 2 wk followed by a reduced calorie diet (RCD), which was lower in fat and higher in carbohydrates and fiber. Cats were fed ad-libitum initially and then food was restricted to achieve 1-2% loss of body weight weekly (11 wk). When lean, cats were fed MD for 2 wk. A standardized meal test (SMT) using a third diet was performed after at least 7 d on each diet, before and after weight loss (four SMT’s total). Glucose, insulin, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) concentrations were measured immediately before and over 6 h after feeding the SMT. Area under the curve (AUC) was compared for GLP-1, GIP, and insulin concentrations using two-way ANOVA. Leaner cats had increased GIPAUC compared to obese cats (P = 0.025). There was a trend towards increased GIPAUC on RCD compared to the MD (P = 0.085). There was a moderate negative correlation between body fat percentage and GLP-1AUC (r = −0.45;. P = 0.05). There was no effect of diet on GLP-1AUC. In conclusion, degree of adiposity and dietary macronutrient content could be important in determining GIP responses not only acutely but also on a long-term basis. Further investigation of GIP responses in cats should take both diet and degree of adiposity into account.

      PubDate: 2017-10-24T21:03:21Z
  • Pro-opiomelanocortin processing and prohormone convertase 1 level in dogs
           with pituitary corticotroph tumours
    • Abstract: Publication date: Available online 13 October 2017
      Source:Domestic Animal Endocrinology
      Author(s): G. Benchekroun, P. de Fornel-Thibaud, D. Rosenberg
      Preliminary data suggest that PC1/3 protein expression and POMC processing are altered in large corticotroph tumours. The aim of this study was to characterize the levels of ACTH precursors and PC1/3 protein in small and large corticotroph tumours of dogs with Cushing’s disease. Pituitary tumours of dogs with Cushing’s disease were collected post-mortem 30 min to 12h after natural death or euthanasia, and classified as small or large. POMC, pro-ACTH and PC1/3 were detected by Western Blotting. Five small and 6 large corticotroph tumours were collected. POMC and pro-ACTH signals were visualised in 5/6 large tumours and in 4/5 small tumours. The strongest signal intensity was observed in 2 large tumours. The PC1/3 signal was weak to undetectable in 6/6 large tumours but strong in 5/5 small tumours. These results suggest differences in PC1/3 protein levels and patterns of POMC processing between large and small corticotroph tumours. If confirmed in larger groups of tumours, further studies will be required to characterise the mechanism involved in these differences.

      PubDate: 2017-10-13T19:24:35Z
  • Orexin system in swine ovarian follicle
    • Abstract: Publication date: Available online 22 September 2017
      Source:Domestic Animal Endocrinology
      Author(s): R. Ciccimarra, S. Bussolati, F. Grasselli, S. Grolli, L. Ragionieri, F. Ravanetti, M. Botti, F. Gazza, A. Cacchioli, R. Di Lecce, A.M. Cantoni, G. Basini
      Successful reproduction is strictly linked to metabolic cues. The orexins are a family of hypothalamic neurohormones, well known for their key role in the control of food intake and the involvement in several aspects of the reproductive process. The biological actions of both orexins are carried out through binding to the related Orexin 1 (OX1R) and Orexin 2 (OX2R) G-protein coupled receptors. The purpose of this study was to investigate the presence of orexin system components in the porcine ovaries, in order to contribute to expand the knowledge about their pleiotropic role. Firstly, we investigated the localization of orexin A (OXA) and its receptors by immunochemistry in different ovarian districts. Thereafter, we evaluated the expression of the prepro-orexin gene and OXA effects on granulosa cell functions. Immunohistochemical study revealed the presence of orexinergic system components in porcine ovarian follicles. Moreover, our data show the expression of prepro-orexin mRNA in swine ovarian follicles > 5 mm. In addition, OXA influences proliferation (P < 0.05), steroidogenic activity (P < 0.05) and redox status of granulosa cells (P < 0.05). Therefore, we hypothesize that OXA could exert a local physiological role in swine ovarian follicles even if further studies are required in order to deeply define the function of this pleiotropic system.

      PubDate: 2017-09-26T15:15:10Z
  • Pharmacodynamics and pharmacokinetics of insulin aspart assessed by use of
           the isoglycemic clamp method in healthy cats
    • Abstract: Publication date: Available online 21 September 2017
      Source:Domestic Animal Endocrinology
      Author(s): H.N. Pipe-Martin, J.M. Fletcher, C. Gilor, M.A. Mitchell
      The objective of this study was to determine the pharmacodynamics (PD) and pharmacokinetics (PK) of insulin aspart in healthy cats following intramuscular (IM) and subcutaneous (SC) injection. Eight healthy, purpose-bred cats were used in a randomized, crossover study design. Each cat had two isoglycemic clamps performed, one after receiving 0.25 IU/kg of insulin aspart by IM injection and one after receiving the same dose by SC injection. The two isoglycemic clamps were performed on different days, at least 48 h apart. The blood glucose, plasma endogenous insulin, and plasma insulin aspart concentrations were measured and the glucose infusion rate (GIR) was recorded during the clamp. The GIR over time was used to create a time-action curve for each clamp which was used to describe the PD of insulin aspart. Data that are normally distributed are reported as mean ± SD, while data that are not normally distributed are reported as median (25 - 75 percentile). When compared to the PD data that have been reported for regular insulin in healthy cats, insulin aspart had a more rapid onset (IM: 10 min [10 - 21.25 min], SC: 12.5 min [10 - 18.75 min]) and shorter duration of action (IM: 182.5 ± 34.33 min, SC: 159.38 ± 41.87 min). The onset of action (P = 0.795), time to peak action (P = 0.499), duration of action (P = 0.301), and total metabolic effect (P = 0.603) did not differ with route of administration; however, SC administration did result in a higher maximum plasma insulin aspart concentration (IM: 1265.17 pmol/L [999.69 – 1433.89 pmol/L], SC: 3278.19 pmol/L [2485.29 – 4132.01 pmol/L], P = 0.000) and larger area under the insulin aspart versus time curve (IM: 82662 ± 30565 pmol/L, SC: 135060 ± 39026 pmol/L, P = 0.010). Insulin aspart has a rapid onset of action and short duration of effect in healthy cats when administered by IM and SC injection. Although it cannot be assumed that the PD and PK of insulin aspart will be the same in cats with diabetic ketoacidosis (DKA), our data supports further investigation into the use of SC insulin aspart as an alternative to regular insulin for the treatment of DKA in cats.

      PubDate: 2017-09-26T15:15:10Z
  • Species-specific control of HGF expression and production in adipocytes in
           a differentiation-dependent manner
    • Abstract: Publication date: Available online 15 September 2017
      Source:Domestic Animal Endocrinology
      Author(s): Daisuke Yamaji, Mohamed M. Soliman, Akihiro Kamikawa, Tomoki Ito, Mohamed M. Ahmed, Yuko Okamatsu-Ogura, Masayuki Saito, Kazuhiro Kimura
      Hepatocyte growth factor (HGF) is a mesenchymal cell-derived factor that regulates cell growth, cell motility, and morphogenesis. Since there are conflicting reports on HGF-producing cells, we herein examined HGF activity in conditioned medium (CM) of bovine and mouse preadipocytes before and after adipogenic differentiation. CM of bovine adipocytes and mouse preadipocytes induced the morphogenesis of mammary epithelial cells that was inhibited by an NK4 HGF antagonist, whereas CM of bovine preadipocytes and mouse adipocytes did not. HGF mRNA expression was increased by a treatment with dexamethasone and isobutylmethylxanthine in bovine as well as human cells, while it was decreased in rodent cells. It was unfortunate that HGF gene promoter activity failed to reflect HGF mRNA expression in these cells. After actinomycin D treatment, expression of HGF mRNA remained stable in pre- and differentiated bovine adipocytes and mouse preadipocytes, while rapidly decreased in mouse differentiated adipocytes. These results indicate that expression and production of HGF are regulated in a species-specific adipogenic differentiation-dependent manner, and suggest the decrease in HGF mRNA in mouse differentiated adipocytes is, at least in part, mediated by differentiation-dependent loss of its stability.

      PubDate: 2017-09-19T12:14:07Z
  • Equine chorionic gonadotropin (eCG) administration after insemination
           affects luteal function and pregnancy establishment in postpartum
           anestrous beef cows
    • Abstract: Publication date: Available online 31 August 2017
      Source:Domestic Animal Endocrinology
      Author(s): R. Núñez-Olivera, T. de Castro, G.A. Bó, J. Piaggio, A. Menchaca
      Two experiments were conducted with the aim of determining the effect of equine chorionic gonadotropin (eCG) administration on day 14 after insemination on ovarian response and pregnancy establishment in postpartum anestrous beef cows. In both experiments, cows were subjected to a progesterone- and estradiol-based treatment for fixed-time artificial insemination (FTAI), and were randomly allocated into four groups to receive or not receive eCG (400 IU) at the time of device removal and/or at 14 d after FTAI. In Experiment 1, from day 14 to 22, daily ultrasonographic determinations were performed to monitor ovarian dynamics, and blood was collected to determine hormone concentrations in 60 cows. In Experiment 2, confirmation of pregnancy was performed at 30 and 60 d after FTAI in 1,060 anestrous cows assigned to the same experimental design. Cows that received eCG on day 14 after FTAI showed increases in corpus luteum area (P < 0.01), follicle diameter (P < 0.05), serum progesterone concentrations (P < 0.01), and estradiol-17β concentrations (P < 0.01), compared with cows that did not receive eCG on day 14. Pregnancy rate on day 30 was greater in those cows that received both eCG treatments (i.e. at device removal and 14 d after insemination) than in those that did not receive eCG treatment (P < 0.05). In conclusion, eCG administered on day 14 after FTAI increases serum progesterone concentrations during the critical period of pregnancy in anestrous cows, and this second eCG treatment seems to have a positive effect on achieving pregnancy.

      PubDate: 2017-09-01T07:53:12Z
  • Human interleukin-6 stimulates bovine satellite cell proliferation through
           a STAT3-dependent mechanism
    • Abstract: Publication date: Available online 31 August 2017
      Source:Domestic Animal Endocrinology
      Author(s): A.M. Brandt, J.M. Kania, B.M. Reinholt, S.E. Johnson
      Bovine satellite cell (bSC) myogenesis and skeletal muscle hypertrophy occur through the orchestrated actions of multiple autocrine and paracrine growth factors. Intimate to the bSC niche is interleukin 6 (IL6), a dual-purpose cytokine with pro-inflammatory and mitogenic properties. The objective of the experiment was to examine the effects of IL6 on proliferation and differentiation of bSC in vitro. Treatment of primary bSC cultures with recombinant bovine IL6 (bIL6) failed to alter myogenesis owing to the absence intracellular signal transduction. The cytokine was able to stimulate phosphorylation of STAT3Y705 in Madin-Darby Bovine Kidney (MDBK) epithelial cells thus, demonstrating bioactivity. Media supplemented with recombinant human IL6 (hIL6) caused phosphorylation of STAT3Y705 in bSC and increased (P < 0.05) proliferation. Inclusion of a STAT3 inhibitor in the media blunted phosphorylation of the STAT3Y705 and suppressed (P < 0.05) hIL6-mediated bSC proliferation. Morphological and biochemical measures of bSC differentiation remained unchanged (P > 0.05) following treatment for 48 hr with hIL6. These results support a role for hIL6 as a bSC mitogen in vitro. The inability of bIL6 to initiate an intracellular signal in bSC requires further investigation.

      PubDate: 2017-09-01T07:53:12Z
  • Corpora lutea in superovulated ewes fed different planes of nutrition
    • Abstract: Publication date: Available online 12 August 2017
      Source:Domestic Animal Endocrinology
      Author(s): A. Kraisoon, D.A. Redmer, C.S. Bass, C. Navanukraw, S.T. Dorsam, V. Valkov, A. Reyaz, A.T. Grazul-Bilska
      The corpus luteum (CL) is an ovarian structure which is critical for the maintenance of reproductive cyclicity and pregnancy support. Diet and/or diet components may affect some luteal functions. FSH is widely used to induce multiple follicle development and superovulation. We hypothesized that FSH would affect luteal function in ewes fed different nutritional planes. Therefore, the aim of this study was to determine if FSH-treatment affects 1) ovulation rate; 2) CL weight; 3) cell proliferation; 4) vascularity; 5) expression of endothelial nitric oxide (eNOS) and soluble guanylyl cyclase (sGC) proteins; and 6) luteal and serum progesterone (P4) concentration in control (C), overfed (O) and underfed (U) ewes at the early- and mid-luteal phases. In addition, data generated from this study were compared to data obtained from non-superovulated sheep and described by Bass et al. [1]. Ewes were categorized by weight, and randomly assigned into nutrition groups: C (2.14 Mcal/kg; n=11), O (2xC; n=12), and U (0.6xC; n=11). Nutritional treatment was initiated 60 d prior to d 0 of the estrous cycle. Ewes were injected with FSH on d 13-15 of the first estrous cycle, and blood samples and ovaries were collected at early- and mid-luteal phases of the second estrous cycle. The number of CL/ewe was determined, and CL were dissected and weighed. CL were fixed for evaluation of expression of Ki67 (a proliferating cell marker), CD31 (an endothelial cell marker), and eNOS and sGC proteins using immunohistochemistry and image analysis. From d 0 until tissue collection, C maintained, O gained and U lost BW. The CL number was greater (P < 0.03) in C and O than U. Weights of CL, cell proliferation, vascularity, and eNOS but not sGC expression were greater (P < 0.001), and serum, but not luteal tissue, P4 concentrations tended to be greater (P = 0.09) at the early- than mid-luteal phase. Comparisons of CL measurements demonstrated greater (P < 0.01) cell proliferation and serum P4 concentration, but less vascularity at the early and mid-luteal phases, and less CL weight at the mid-luteal phase in superovulated than non-superovulated ewes; however, concentration of P4 in luteal tissues was similar in both groups. Thus, in superovulated ewes, luteal cell proliferation and vascularity, expression of eNOS, and serum P4 concentration depends on the stage of luteal development, but not diet. Comparison to control ewes demonstrated several differences and some similarities in luteal functions after FSH-induced superovulation.

      PubDate: 2017-08-22T06:17:52Z
  • Role of FKBP51 in the modulation of the expression of the corticosteroid
           receptors in bovine thymus following glucocorticoid administration
    • Abstract: Publication date: Available online 8 August 2017
      Source:Domestic Animal Endocrinology
      Author(s): L. Starvaggi Cucuzza, B. Biolatti, F.E. Scaglione, F.T. Cannizzo
      The aim of this work was to study the transcriptional effects of glucocorticoids on corticosteroid hormone receptors, prereceptors (11β-hydroxysteroid dehydrogenase 1 and 2, 11β-HSD1 and 2) and chaperones molecules regulating intracellular trafficking of the receptors (FKBP51 and FKBP52) in thymus of veal calves. Moreover, the expression of FKBP51 and FKBP52 gene were investigated in beef cattle thymus. In the cervical thymus of veal calves dexamethasone administration in combination with estradiol decreased FKBP51 expression (P < 0.01). The same treatment increased mineralocorticoid receptor (MR) (P < 0.01) and 11β-HSD1 expression (P < 0.05) compared to control group in the cervical thymus of veal calves. The thoracic thymus of veal calves treated with dexamethasone and estradiol showed a decreasing of FKBP51 (P < 0.05), FKBP52 (P < 0.05), glucocorticoid receptor (P < 0.05) and MR expression (P < 0.05) compared to control group in the thoracic thymus of veal calves. The gene expression of FKBP51 decreased both in cervical (P < 0.01) and thoracic thymus (P < 0.01) of beef cattle treated with dexamethasone and estradiol. Additionally, also prednisolone administration reduced FKBP51 expression in the cervical thymus (P < 0.01) and in the thoracic thymus of beef cattle (P < 0.01). The gene expression of FKBP52 increased only in the cervical thymus following dexamethasone administration (P < 0.01). The decrease of FKBP51 gene expression in thymus could be a possible biomarker of illicit dexamethasone administration in bovine husbandry. Moreover, so far an effective biomarker of prednisolone administration is not identified. In this context, the decrease of FKBP51 gene expression in thymus of beef cattle following prednisolone administration could play an important role in the indirect identification of animals illegally treated with prednisolone.

      PubDate: 2017-08-11T10:46:16Z
  • Early prenatal androgen exposure reduces testes size and sperm
           concentration in sheep without altering neuroendocrine differentiation and
           masculine sexual behavior
    • Abstract: Publication date: Available online 29 July 2017
      Source:Domestic Animal Endocrinology
      Author(s): C.M. Scully, C.T. Estill, R. Amodei, A. McKune, K.P. Gribbin, M. Meaker, F. Stormshak, C.E. Roselli
      Prenatal androgens are largely responsible for growth and differentiation of the genital tract and testis and for organization of the control mechanisms regulating male reproductive physiology and behavior. The aim of the present study was to evaluate the impact of inappropriate exposure to excess testosterone (T) during the first trimester of fetal development on the reproductive function, sexual behavior and fertility potential of rams. We found that biweekly maternal T propionate (100 mg) treatment administered from day 30 to day 58 of gestation significantly decreased (P < 0.05) postpubertal scrotal circumference and sperm concentration. Prenatal T exposure did not alter ejaculate volume, sperm motility and morphology or testis morphology. There was, however, a trend for more T-exposed rams than controls to be classified as unsatisfactory potential breeders during breeding soundness exams. Postnatal serum T concentrations were not affected by prenatal T exposure, nor was the expression of key testicular genes essential for spermatogenesis and steroidogenesis. Basal serum LH did not differ between treatment groups, nor did pituitary responsiveness to GnRH. T-exposed rams, like control males, exhibited vigorous libido and were sexually attracted to estrous females. In summary, these results suggest that exposure to exogenous T during the first trimester of gestation can negatively impact spermatogenesis and compromise the reproductive fitness of rams.

      PubDate: 2017-08-01T07:14:05Z
  • Ghrelin plasma concentration does not covary with energy demand in adult
           laying hens
    • Abstract: Publication date: Available online 29 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): A. Höhne, L. Schrader, S. Weigend, S. Petow
      The peptide hormone ghrelin is suggested to be involved in food intake regulation in young growing chicken. Whether ghrelin is involved in the regulation of energetic balance associated with laying performance in adult laying hens was studied by use of 4 chicken lines that differ in laying performance and phylogeny (4 lines; 16 hens per line). As housing conditions are also known to affect energy demand, half of the hens per line were housed in single cages and the other half of hens were maintained in a floor housing system. Plasma samples were collected at 17 to 19, 33 to 35, 49 to 51 and 72 wk of age and analyzed with a chicken ghrelin ELISA Kit. From caged hens, individual food consumption and laying performance additionally was recorded. Due to its function in growth and its relationship with Ghrelin, also GH plasma concentrations were analyzed. Ghrelin concentrations did not differ between the four lines at any of the test periods (all P > 0.05). Ghrelin was negatively related to food consumption only in the growing period of the high performing lines (both P < 0.0001). During this phase, floor-housed hens showed greater ghrelin concentrations compared to caged hens (P < 0.0001). Our results suggest that in adult layers ghrelin is not involved in regulating energy intake related to laying performance but rather seems to be related to body growth and housing condition before start of lay, the latter possibly due to differences in hens’ behavioral activity.

      PubDate: 2017-07-04T21:30:03Z
  • An exploratory study of competition scores and salivary cortisol
           concentrations in Warmblood horses
    • Abstract: Publication date: Available online 28 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): R. Munk, R.B. Jensen, R. Palme, L. Munksgaard, J.W. Christensen
      The main objective of this explorative study was to describe the relationship between competition scores and salivary cortisol concentrations in young horses during dressage and showjumping competitions. The study also investigated whether the diurnal rhythm of salivary cortisol concentrations was affected by competition over consecutive days compared to the home environment. Saliva samples were collected from 126 dressage horses and showjumpers in their home environment and at three different events. The relationship between scores given by judges at the competition and cortisol concentrations at the event was assessed. The results demonstrated that competition scores correlated positively to baseline cortisol concentrations at one out of three events (r = 0.53, P < 0.001). Salivary cortisol concentrations followed a diurnal rhythm with the highest concentrations measured in the morning and the lowest in the evening, both at home and in the competition environment (P < 0.05). Salivary cortisol concentrations were greater during the competitions than at home (P < 0.05) except at one event where showjumpers did not increase between home and competition. Dressage horses had the highest baseline cortisol concentrations at competition, and exercise caused cortisol concentrations to increase in both showjumpers and dressage horses (P < 0.001). In conclusion, the diurnal rhythm in salivary cortisol concentrations was maintained in the novel environment. Dressage horses demonstrated greater baseline cortisol concentrations at competition than showjumpers, suggesting that they may perceive the novel environment as more stressful. Furthermore, there was no consistent relationship between baseline salivary cortisol concentrations and competition scores across events.

      PubDate: 2017-07-04T21:30:03Z
  • Ovarian steroids, oxytocin and tumor necrosis factor modulate equine
           oviduct function
    • Abstract: Publication date: Available online 24 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): P. Pinto-Bravo, A. Galvão, M.R. Rebordão, A. Amaral, D. Ramilo, E. Silva, A. Szóstek-Mioduchowska, G. Alexandre-Pires, R. Roberto da Costa, D.J. Skarzynski, G. Ferreira-Dias
      The oviduct plays important roles in the early reproductive process. The aim of this study was to evaluate gene transcription and protein expression of progesterone receptor (PGR), estrogen receptors 1 (ESR1) and 2 (ESR2); oxytocin receptor (OXTR); prostaglandin F2α synthase (AKR1C3) and prostaglandin E2 synthase (PTGES) in mare oviduct in different estrous cycle stages. Estradiol (E2), progesterone (P4), oxytocin (OXT) and Tumor Necrosis Factor α (TNF) effect on in vitro PGE2 and PGF2α secretion by equine oviduct explants or by oviduct epithelial cells (OEC) were also assessed. During the breeding season, oviduct tissue was obtained post-mortem from cyclic mares. Protein of ESR1, ESR2, PGR, AKR1C3 and PTGES was present in oviduct epithelial cells (OEC), while OXTR was shown in oviduct stroma. In follicular phase, protein expression of ESR1, ESR2, PGR and OXTR increased in oviduct explants (P < 0.05), while no estrous cycle effect was noted for AKR1C3 or PTGES. In follicular phase, mRNA transcription was up-regulated for Pgr but down-regulated for Oxtr, Ptges and Akr1c3 (P < 0.05). Nevertheless, Esr1 and Esr2 mRNA levels did not change with the estrous cycle. In the ampulla, Esr1, Esr2, and Oxtr mRNA transcription increased, but not for Pgr or Ptges. In contrast, Akr1c3 mRNA level was up-regulated in the infundibulum (P < 0.05). In follicular phase, E2, P4 and OXT down-regulated PGE2 production by OEC (P < 0.05), but no difference was observed in mid-luteal phase. Explants production of PGE2 rose when treated with OXT in follicular phase; with TNF or OXT in early luteal phase; or with TNF, OXT or P4 in mid-luteal phase. PGF2α production by OEC was down-regulated by all treatments in follicular phase, but up-regulated in mid-luteal phase (P < 0.05). Oviduct explants PGF2α production was stimulated by TNF or OXT in all estrous cycle phases. In conclusion, this work has shown that ESR1, ESR2, OXTR, PTGES and AKRLC3 gene transcription and/or translation is estrous cycle dependent and varies with oviduct portion (infundibulum vs ampulla) and cell type. Ovarian steroid hormones, OXT and TNF stimulation of PGF2α and/or PGE2 production is also estrous cycle dependent and varies in the different portions of mare oviduct. Differential transcription level and protein localization in various portions of the oviduct throughout the estrous cycle, as well as PG production, suggest coordinated physiologic actions and mechanisms of steroid hormones, OXT and TNF in the equine oviduct.

      PubDate: 2017-07-04T21:30:03Z
  • Puberty Arises with Testicular Alterations and Defective AMH Expression in
           Rams Prenatally Exposed to Testosterone
    • Abstract: Publication date: Available online 23 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): S.E. Recabarren, M. Recabarren, D. Sandoval, A. Carrasco, V. Padmanabhan, R. Rey, H.G. Richter, C.C. Perez-Marin, T. Sir-Petermann, P.P. Rojas-Garcia
      The male gonadal tissue can be a sensitive target to the reprogramming effects of testosterone (T) during prenatal development. We have demonstrated that male lambs born to dams receiving T during pregnancy – a model system to the polycystic ovary syndrome (PCOS)- show a decreased number of germ cells early in life, and when adult, a reduced amount of sperm and ejaculate volume. These findings are key to put attention to the male offspring of women bearing PCOS, as they are exposed to increased levels of androgen during pregnancy which can reprogram their reproductive outcome. A possible origin of these defects can be a disruption in the expression of the Antimüllerian hormone (AMH), due to its critical role in gonadal function at many postnatal stages, hence, prior to puberty. Therefore, we addressed the impact of prenatal T excess on the expression of AMH and factors related to its expression like AP2, SOX9, FSHR and AR in the testicular tissue through realtime PCR during the peripubertal age. We also analyzed the testicular morphology and quantified the number of Sertoli cells and germ cells in order to evaluate any further defect in the testicle. Experiments were performed in rams at 24 wk of age, hence, prior puberty. The experimental animals (T-males) consisted of rams born to mothers receiving 30 mg testosterone twice a week from day 30 to 90 of pregnancy and then increased to 40 mg until day 120 of pregnancy. The control males (C-males) were born to mothers receiving the vehicle of the hormone. We found a significant increase in the expression of the mRNA of AMH and SOX9, but not of the AP2, FHSR nor AR, in the T-males. Moreover, T-males showed a dramatic decrease in the number of germ cells, together with a decrease in the weight of their testicles. The findings of the present study show that prior to puberty, T-males are manifesting clear signs of disruption in the gonadal functions probably due to an alteration in the expression pattern of the AMH gene. The precise way by which T reprograms the expression of AMH gene remains to be established.

      PubDate: 2017-06-23T19:54:19Z
  • Effects of short-term fasting on the Akt-mediated pathway involved in
           protein metabolism in chicken skeletal muscle
    • Abstract: Publication date: Available online 22 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): T. Saneyasu, N. Tsuchii, Y. Nakano, A. Kitashiro, T. Tsuchihashi, H. Shindo, K. Honda, H. Kamisoyama
      In the present study, we show that short-term (4 h) fasting significantly decreased the levels of protein synthesis-related factors such as the plasma insulin concentration, skeletal muscle pAkt and pS6 levels in 2-week-old chickens (P < 0.05). An intravenous injection of insulin significantly elevated the contents of pAkt and p-S6 in the skeletal muscle (P < 0.05). These findings suggest that the decreasing the plasma insulin causes the downregulation of the Akt/S6 pathway in chicken skeletal muscle under short-term fasting conditions. However, protein synthesis was not significantly affected by short-term fasting. In addition , no significant change was observed in the levels of proteolysis-related factors such as plasma Nτ-methylhistidine, phosphorylated forkhead box class O (pFOXO-1), and muscle ring finger-1 during 4-h fasting, indicating that short term fasting does not induce skeletal muscle proteolysis in chickens. Interestingly, atrogin-1 expression significantly increased after 2-h fasting (P < 0.05), and insulin injection significantly reversed the fasting-induced atrogin-1 expression in chicken skeletal muscle (P < 0.05). Collectively, these findings suggest that short-term fasting downregulates the insulin-stimulated Akt/S6 pathway but does not significantly affect protein synthesis and proteolysis in chicken skeletal muscle, and that atrogin-1 expression is upregulated in a FOXO-1-independent manners.

      PubDate: 2017-06-23T19:54:19Z
  • Comparison of surrogate indices for insulin sensitivity with parameters of
           the intravenous glucose tolerance test in early lactation dairy cattle
    • Abstract: Publication date: Available online 15 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): V. Alves-Nores, C. Castillo, J. Hernandez, A. Abuelo
      The aim of this study was to investigate the correlation between different surrogate indices and parameters of the intravenous glucose tolerance test (IVGTT) in dairy cows at the start of their lactation. Ten dairy cows underwent IVGTT on days 3 to 7 after calving. Areas under the curve during the 90 min following infusion, peak and nadir concentrations, elimination rates, and times to reach half-maximal and basal concentrations for glucose, insulin, nonesterified fatty acids, and β-hydroxybutyrate were calculated. Surrogate indices were computed using the average of the IVGTT basal samples, and their correlation with the IVGTT parameters studied through the Spearman’s rank test. No statistically significant or strong correlation coefficients (P > 0.05; r < 0.50) were observed between the insulin sensitivity measures derived from the IVGTT and any of the surrogate indices. Therefore, these results support that the assessment of insulin sensitivity in early lactation cattle cannot rely on the calculation of surrogate indices in just a blood sample, and the more laborious tests (i.e., hyperinsulinemic euglycemic clamp test or IVGTT) should be employed to predict the sensitivity of the peripheral tissues to insulin accurately.

      PubDate: 2017-06-18T18:46:54Z
  • Growth hormone (GH)-specific induction of the nuclear localization of
           porcine growth hormone receptor (pGHR) in the porcine hepatocytes
    • Abstract: Publication date: Available online 8 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): H.N. Lan, P. Hong, R.N. Li, A.S. Shan, X. Zheng
      The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR’s nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR’s nuclear localization were analysed and demonstrated that pGHR’s nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR’s nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, while further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal.

      PubDate: 2017-06-08T16:53:00Z
  • Adipose triglyceride lipase protein abundance and translocation to the
           lipid droplet increase during leptin induced lipolysis in bovine
    • Abstract: Publication date: Available online 8 June 2017
      Source:Domestic Animal Endocrinology
      Author(s): D.A. Koltes, M.E. Spurlock, D.M. Spurlock
      Proper regulation of lipid metabolism is critical for preventing the development of metabolic diseases. It is clear that leptin plays a critical role in the regulation of energy homeostasis by regulating energy intake. However, leptin can also regulate energy homeostasis by inducing lipolysis in adipocytes, but it’s unclear how the major lipases are involved in leptin-stimulated lipolysis. Therefore, the objectives of this study were to determine if 1) leptin acts directly to induce lipolysis in bovine adipocytes 2) the potential lipases involved in leptin induced lipolysis in bovine adipocytes and 3) increases translocation of adipose triglyceride lipase (ATGL) and hormone sensitive lipase (HSL) during leptin-stimulated lipolysis in bovine stromal vascular cell derived adipocytes. As hypothesized, leptin induced a lipolytic response (P = 0.02) in isolated adipocytes which was accompanied by an increase in phosphorylation of signal transducer and activator of transcription (STAT)3 (P = 0.03), a well-documented secondary messenger of leptin, and ATGL protein abundance (P < 0.01). Protein abundance of STAT3, perilipin, HSL and phosphorylation of HSL by PKA and AMPK were not altered during leptin-stimulated lipolysis (P > 0.05). Immunostaining techniques were imployed to determine the location of HSL and ATGL. Both lipases translocated to the lipid droplet after 2 h of exposure to isoproterenol (P < 0.02). However, only ATGL was translocated to the lipid droplet during leptin-stimulated lipolysis (P = 0.04), indicating ATGL may be the active lipase in leptin-stimulated lipolysis. In summary, leptin stimulates lipolysis in bovine adipocytes. The lack of phosphorylated HSL and translocation of HSL to the lipid droplet during leptin-stimulated lipolysis suggest minimal activity by PKA. Interestingly, leptin-stimulated lipolysis is accompanied by an increase in ATGL protein abundance and translocation to the lipid droplet, indicating its involvement in leptin-stimulated lipolysis either due to an increase in protein abundance or through a novel lipolytic cascade.

      PubDate: 2017-06-08T16:53:00Z
  • Insulin signaling in various equine tissues under basal conditions and
           acute stimulation by intravenously-injected insulin
    • Abstract: Publication date: Available online 12 May 2017
      Source:Domestic Animal Endocrinology
      Author(s): T. Warnken, R. Brehm, K. Feige, K. Huber
      The aim of the study was to analyze key proteins of the equine insulin signaling cascade and their extent of phosphorylation in biopsies from muscle tissue (MT), liver tissue (LT), and nuchal (NUAT), subcutaneous (SCAT) and retroperitoneal adipose tissues (RPAT). This was investigated under unstimulated (B1) and intravenously insulin stimulated (B2) conditions, which were achieved by injection of insulin (0.1 IU/kg bodyweight (BW)) and glucose (150 mg/kg BW). Twelve warmblood horses aged 15 ± 6.8 years (yr), weighing 559 ± 79 kg and with a mean body condition score of 4.7 ± 1.5 were included in the study. Key proteins of the insulin signaling cascade were semi-quantitatively determined using western blotting. Furthermore, modulation of the cascade was assessed. The basal expression of the proteins was only slightly influenced during the experimental period. Insulin induced a high extent of phosphorylation of insulin receptor (InsR) in LT (P < 0.01) but not in MT. Protein kinase B (PKB) and mechanistic target of rapamycin (mTOR) expressed a higher extent of phosphorylation in all tissues in B2 biopsies. Adenosine monophosphate protein kinase (AMPK), as a component related to insulin signaling, expressed enhanced phosphorylation in MT (P < 0.05) and adipose tissues (NUAT P < 0.05; SCAT P < 0.01; RPAT P < 0.05), but not in LT at B2. Tissue-specific variations in the acute response of insulin signaling to intravenously injected insulin were observed. In conclusion, insulin sensitivity in healthy horses is based on a complex concerted action of different tissues by their variations in the molecular response to insulin.

      PubDate: 2017-05-15T10:58:07Z
  • Effects of non-glycosylated and glycosylated prolactin on basal and
           gonadotropin-stimulated steroidogenesis in chicken ovarian follicles
    • Abstract: Publication date: Available online 10 May 2017
      Source:Domestic Animal Endocrinology
      Author(s): S.Q. Hu, D. Zadworny
      In galliformes, the circulating isoform of prolactin (PRL) significantly changes during different reproductive states. However, the role of the major isoform (glycosylated PRL, G-PRL) in ovarian steroidogenesis is unknown. The present study aimed to compare the effects of non-glycosylated (NG-) and G-PRL on basal and gonadotropin-stimulated estradiol (E2) and progesterone (P4) production in granulosa cells or follicular walls of chicken different size class follicles. In the initial experiment, granulosa cells of preovulatory F3-F1 and prehierarchical 6-8 mm follicles were incubated for 24 with different concentrations of NG- or G-PRL (0,1 ,10 ,100 or 1000 ng/mL). In the subsequent experiments, these categorized granulosa cells and follicular walls of prehierarchical 4-6, 2-4 and < 2 mm follicles were incubated for 24 h in the absence and presence of 10 ng/mL FSH or LH, or in combination with different concentrations of NG- or G-PRL (10, 100 or 1000 ng/mL). We observed that lower levels of NG-PRL induced (P < 0.05) E2 and P4 secretion in granulosa cells of either preovulatory or prehierarchical follicles but at higher levels this effect was reduced. In contrast, G-PRL promoted (P < 0.05) basal E2 and P4 secretion in preovulatory granulosa cells but was inhibitory (P < 0.05) in prehierarchical granulosa cells. Results obtained by real-time qPCR demonstrated that these effects were mediated through modulation the expression of StAR, CYP11A1, CYP19A1 and 3β-HSD. Furthermore, G-PRL was less potent than NG-PRL in inhibiting FSH- or LH-stimulated E2 and P4 production in granulosa cells of preovulatory follicles, whereas NG-PRL enhanced (P < 0.05) but G-PRL reduced (P < 0.05) FSH-induced P4 production in those of prehierarchical follicles. In follicular walls from each group of prehierarchical 4-6, 2-4 and < 2 mm follicles, NG- and G-PRL had both stimulatory and inhibitory influences on the actions of FSH on E2 and P4 secretion, but both suppressed (P < 0.05) LH-induced E2 and P4 secretion except for the synergistic effects of LH and G-PRL on P4 secretion by follicular walls of the 4-6 mm follicles. Taken together, these results suggest that both NG- and G-PRL are biologically active in regulating basal and gonadotropin-stimulated E2 and P4 production in chicken ovarian follicles. However, their effects are different depending on the concentration, the type of gonadotropin (FSH or LH) and the stage of follicle development.

      PubDate: 2017-05-15T10:58:07Z
  • Glucocorticoid receptor number and affinity differ between peripheral
           blood mononuclear cells and granulocytes in domestic pigs
    • Abstract: Publication date: Available online 8 May 2017
      Source:Domestic Animal Endocrinology
      Author(s): L.C. Engert, U. Weiler, V. Stefanski, S.S. Schmucker
      The aim of the present study was to characterize the number and affinity of glucocorticoid receptors (GR) in peripheral blood mononuclear cells (PBMC) and granulocytes of domestic pigs because glucocorticoid signaling is considered important for animal health and welfare. To investigate GR binding characteristics in intact porcine immune cells, blood samples of six castrated male pigs were collected via indwelling vein catheters. Porcine PBMC and granulocytes were isolated using two-layer density gradients, followed by radioligand binding assays to determine the number of GR sites per cell and the dissociation constant Kd as a measure for GR binding affinity. The present study revealed a greater number of GR sites per cell (P = 0.039) in PBMC (mean ± SEM: 1953 ± 207 sites/cell) compared to granulocytes (1561 ± 159 sites/cell) in domestic pigs. Furthermore, porcine PBMC had a higher GR binding affinity than porcine granulocytes (P = 0.003) as the dissociation constant Kd of PBMC (1.8 ± 0.2 nM) was lower than that of granulocytes (3.5 ± 0.4 nM). Our results point to differences in underlying mechanisms of glucocorticoid signaling in different porcine leukocyte populations.

      PubDate: 2017-05-10T09:31:19Z
  • Effect of growth hormone on steroid concentrations and mRNA expression of
           their receptor, and selected egg-specific protein genes in the chicken
           oviduct during pause in laying induced by fasting
    • Abstract: Publication date: Available online 8 May 2017
      Source:Domestic Animal Endocrinology
      Author(s): J.K. Socha, A. Sechman, M. Mika, A. Hrabia
      This study was undertaken to examine the effect of growth hormone (GH) treatment during pause in laying on (1) the concentration of steroids in blood plasma and oviduct tissues, (2) the expression of mRNA of steroid receptors, and (3) the mRNA expression of selected egg-specific proteins in the chicken oviduct. A pause in egg laying was induced by food deprivation for 5 d, followed by feeding every other day, and then feeding daily from day 10 onwards. Birds were divided into three groups: control (n = 18) fed ad libitum, subjected to pause in laying (n = 18), and subjected to pause in laying and injected every day with 200 μg/kg BW of chicken GH (chGH; n = 18). The oviduct was isolated from hens of each group on days 6 (when the oviduct was regressed), 13 (during oviduct recrudescence), and 17 or 20 (rejuvenated oviduct) of the experiment. Fasting caused a decrease in plasma concentrations of progesterone (P4), testosterone, and estradiol on day 6 and a reduction in tissue concentrations of these steroids on days 6 and 13. Fasting also caused an increased relative expression of estrogen receptor α and β (ERα, ERβ) and progesterone receptor (PR) in the magnum and shell gland on day 6, increased ERα and PR in the magnum on days 13 and 17 or 20, and increased androgen receptor (AR) mRNA in the magnum on days 6 and 13 and in the shell gland on day 13. A fasting-induced elevation in ovocalyxin-36 mRNA expression on day 6 and a decrease in avidin mRNA on days 6 and 13 and in ovocleidin-116 on day 13 were also observed (P < 0.05 to P < 0.001). Administration of chGH abolished the fasting-induced decrease in concentration of steroids in plasma and tissues. Furthermore, chGH enhanced the effect of fasting on mRNA expression of PR, ERα, and avidin in the magnum on day 6, and ERα in the shell gland on day 13. The gene expression of ovalbumin on days 6 and 13, ovocalyxin-36 and ovocleidin-116 on day 6 was decreased in chGH-treated chickens. In contrast, the expression of ovalbumin on day 17 or 20 was increased (P < 0.05 to P < 0.001). The results obtained indicate that, by alterations in the concentration of steroid hormones and their receptor expression in the chicken oviduct, GH determines the rate of regression and rejuvenation of this organ during molting. Moreover, changes in the expression of selected egg proteins indicate that GH might be the regulator of the secretory activity of the hen oviduct.

      PubDate: 2017-05-10T09:31:19Z
  • Intergenerational Impact of Maternal Overnutrition and Obesity Throughout
           Pregnancy in Sheep on Metabolic Syndrome in Grandsons and Granddaughters
    • Abstract: Publication date: Available online 22 April 2017
      Source:Domestic Animal Endocrinology
      Author(s): C.L. Pankey, M.W. Walton, J.F. Odhiambo, A.M. Smith, A.B. Ghnenis, P.W. Nathanielsz, S.P. Ford
      We previously reported that maternal overnutrition and obesity (MO) throughout pregnancy and lactation in sheep (MOF0) decreases term fetal pancreatic β-cell numbers and increases perirenal adiposity producing hyperphagia, increased adiposity and insulin resistance in adult female offspring (MOF1) fed ad libitum. Pregnant female MOF1 exhibited increased blood glucose from mid to late gestation vs. control F1 (CTRF1) though both groups ate only to NRC recommendations. MOF1 ewes delivered female offspring (F2) who like their MOF1 mothers exhibited increased abdominal adiposity and absent neonatal leptin surge. In the current work we determined if adult MOF2 exhibited metabolic syndrome components when fed ad libitum. After weaning, MOF2 males (n=5), MOF2 females (n=6), CTRF2 males (n=5), and CTRF2 females (n=6) were fed to NRC requirements until 19 mo followed by 12-wk ad libitum feeding. Body weight and % fat increased (P < 0.01) in all F2 during this feeding trial. MOF2 males were heavier (P < 0.01) than CTRF2 males and females, and MOF2 females throughout the trial. By week 8, baseline blood glucose concentrations increased (P < 0.001) in MOF2 females, but not other groups, remaining elevated throughout the trial. Baseline insulin was similar through week 6, increasing (P < 0.05) at week 8 in MOF2 females only. MOF2 female insulin returned to CTRF2 female levels during weeks 10 and 12. The progressive increase of plasma glucose on week 8 in association with increased insulin in MOF2 females but not other groups demonstrated a diet-induced increase (P < 0.001) in MOF2 female insulin resistance. The subsequent decline in insulin during weeks 10 and 12 despite elevated glucose in MOF2 females is consistent with a decrease in glucose-stimulated pancreatic β-cell function. These data indicate that ad libitum feeding exceeds the pancreatic secretory response predisposing MOF2 females to hyperglycemia. Further, there was a sex difference where MOF2 males increased body mass and MOF2 females displayed insulin/glucose dysregulation.

      PubDate: 2017-04-28T06:24:43Z
  • A sandwich ELISA for porcine alpha-1acid glycoprotein (pAGP, ORM-1) and
           further demonstration of its use to evaluate growth potential in newborn
    • 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
    • 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
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
Home (Search)
Subjects A-Z
Publishers A-Z
Your IP address:
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-