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  Subjects -> VETERINARY SCIENCE (Total: 182 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access  
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 7)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 16)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 246)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 5)
Annales UMCS, Medicina Veterinaria     Open Access  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 4)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 1)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access  
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
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: 7)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Rural     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 4)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 3)
Equine Health     Full-text available via subscription  
Equine Veterinary Education     Hybrid Journal   (Followers: 7)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 2)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
ISRN Veterinary Science     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 9)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 22)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 4)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Hybrid Journal   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 8)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Kufa Journal For Veterinary Medical Sciences     Open Access  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 3)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 3)
Medical Mycology Case Reports     Open Access  

        1 2     

Journal Cover Domestic Animal Endocrinology
   [5 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0739-7240
     Published by Elsevier Homepage  [2573 journals]   [SJR: 0.75]   [H-I: 50]
  • Expression of variant transcripts of the KCTD15 gene and their association
           with fatness traits in chickens
    • Abstract: Publication date: Available online 2 October 2014
      Source:Domestic Animal Endocrinology
      Author(s): S.S. Liang , H.J. Ouyang , J. Liu , B. Chen , Q.H. Nie , X.Q. Zhang
      The aim of this study was to characterize the structure, expression and biological functions of potassium channel tetramerisation domain containing 15 (KCTD15) in chickens. We compared the KCTD15 expression level in samples of hypothalamic, adipose, and liver tissue of Xinghua (XH) chickens that were maintained on different dietary status. An association analysis of KCTD15 gene variant transcripts with fatness traits in a F2 resource population of chickens was performed. Three KCTD15 transcripts were identified in which the complete transcript was predominantly expressed in adipose tissue and the hypothalamus. The chicken KCTD15 gene was regulated by both feeding, fasting and by consumption of a high fat diet. The expression level of KCTD15 gene was markedly decreased in hypothalamus and liver of fasted, re-fed chickens (P < 0.05), and significantly down-regulated in adipose tissue by the high fat diet (P < 0.05). Three single nucleotide polymorphisms (SNPs) of the KCTD15 gene were significantly associated with a number of fatness traits in chicken (P < 0.05). These results suggest that KCTD15 have a potential role regulation of obesity and fat metabolism in chickens.

      PubDate: 2014-10-03T14:43:46Z
  • "Relationship between plasma and tissue corticosterone in laying hens
           (Gallus gallus domesticus): implications for stress physiology and animal
    • Abstract: Publication date: Available online 2 October 2014
      Source:Domestic Animal Endocrinology
      Author(s): C.R. Ralph , P.H. Hemsworth , B.J. Leury , A.J. Tilbrook
      This study directly compared the dynamics of change in plasma corticosterone concentration with the dynamics of change in tissue corticosterone concentration in laying hens. In concert we measured the rate of gluconeogenesis, glycogenesis and glycolysis in the liver, kidney, skeletal muscle and heart. We evaluated these changes acutely - over 3 h in response to an ACTH injection - and chronically - over 24 h in response to food and water deprivation. In response to ACTH injection there was a significant (P < 0.05) increase in plasma corticosterone concentration and a parallel significant increase in corticosterone concentration in the skeletal muscle, kidney and heart. However, the change in corticosterone concentration in the liver did not parallel the plasma, at times it was greater than the plasma and there was a second significant increase (P < 0.05) in corticosterone concentration in the liver after 180 min. Under these conditions the rate of gluconeogenesis in the liver decreased and the rate of glycogenesis increased. In contrast, after 12 h and 24 h of food and water deprivation plasma corticosterone concentration was increased and this was paralleled by increased corticosterone concentration in the liver, an increase in the rate of gluconeogenesis and a decrease in the rate of glycogenesis. After ACTH injection glucose concentration in the liver was not significantly depleted but after 12 h or 24 h of food and water deprivation it was significantly depleted (P < 0.05). Plasma corticosterone concentration provided different insight into the effect of the stressor on hen physiology under acute and chronic conditions. Our data suggest that extending our evaluation of stress to the site of corticosterone action, that is, the target tissue, may enhance our ability to evaluate stress and the welfare of laying hens.

      PubDate: 2014-10-03T14:43:46Z
  • Modulation of periovulatory endocrine profiles in beef cows: consequences
           for endometrial glucose transporters and uterine fluid glucose levels
    • Abstract: Publication date: Available online 28 September 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.R. França , F.S. Mesquita , E. Lopes , G. Pugliesi , V. Van Hoeck , M.R. Chiaratti , C.B. Membrive , P. Papa , M. Binelli
      In beef cattle, proestrus estradiol and subsequent progesterone (P4) concentrations can regulate the endometrial characteristics and thereby determine maternal receptivity towards the embryo. However, the underlying mechanisms linking peri-ovulatory endocrine profiles to receptivity, which is crucial to obtain pregnancy, need to be elucidated. We hypothesized that the size of the pre-ovulatory follicle (POF) and subsequent circulating P4 concentrations, during early diestrus, modulate endometrial levels of glucose transporter transcripts and proteins, and subsequently affect the luminal glucose availability in the uterus. Therefore, follicle growth of Nelore cows was manipulated and cows were assigned to two experimental groups: i) LF-LCL group with a large POF and CL and ii) SF-SCL group with a small POF and CL. At day 7 post GnRH-induced ovulation (GnRH treatment = day 0), animals were slaughtered (n = 18 per group) and uterine tissues and washings were collected for characterization of glucose transporters and glucose levels, respectively. The diameter of POF was larger (P < 0.05) in the LF-LCL cows compared to their SF-SCL counterparts (12.8 ± 0.4 vs. 11.1 ± 0.4 mm). Furthermore, CL size (17.49 ± 0.88 vs. 14.48 ± 0.52 mm) and circulating P4 concentrations at day 7 (4.5 ± 1.0 vs. 3.3 ± 1.1 ng/mL, P < 0.05) were significantly higher in the LF-LCL cows compared to the SF-SCL cows. No differences (P > 0.05) were detected in gene expression patterns of SLC2A1, SLC2A3, SLC2A4, SLC2A5, SLC5A1, ATP1A2, ATP1B2 and SLC37A4. However, the protein abundance of endometrial SLC2A1was increased in the LF-LCL group compared to the SF-SCL group (P < 0.05). SLC2A1 and SLC2A4 protein products were mainly identified at the endometrial luminal and glandular epithelium membranes as well as in the endometrial stroma. Glucose concentrations in uterine washings were similar between groups. In conclusion, we provided information on the potential link between endocrine profiles and of glucose transport pathways in the bovine endometrium. More specifically, our data revealed that the size of the POF, and subsequent P4 concentrations, did not functionally affect the main endometrial glucose transporter pathways or uterine fluid glucose concentrations during diestrus.

      PubDate: 2014-10-03T14:43:46Z
  • Obituary
    • Abstract: Publication date: Available online 27 September 2014
      Source:Domestic Animal Endocrinology

      PubDate: 2014-09-28T12:13:46Z
  • Duration of maternal undernutrition differentially alters fetal growth and
           hormone concentrations
    • Abstract: Publication date: Available online 19 September 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.E. Field , R.V. Anthony , T.E. Engle , S.L. Archibeque , D.H. Keisler , H. Han
      To investigate the impact of duration of maternal undernutrition in twin sheep pregnancies, ewes were either fed 100% (C), or 50% of their nutrient requirements from 28 to 78 d gestational age (dGA) and readjusted to 100% beginning at 79 dGA (LC), or continuously restricted from 28 to 135 dGA (LL). Weights of the fetus, empty carcass, brain, and liver were greater in the LC than LL fetuses at 135 dGA (P ≤ 0.05). While umbilical vein (UmV) glucose concentrations did not differ, the UmV:umbilical artery (UmA) glucose gradient was smaller (0.26 ± 0.03 vs 0.38 ± 0.03 and 0.39 ± 0.04 mmol L-1; P ≤ 0.05) in LL than C and LC fetuses, respectively. Umbilical vein concentrations of IGF-1 were less (46.7 ± 5.62 vs 74.3 ± 6.71 ng/ml; P ≤ 0.05) in LL than LC fetuses. Additionally, LL fetuses tended (P ≤ 0.10) to have lower UmA concentrations of insulin (0.24 ± 0.13 vs 0.70 ± 0.15 ng/ml) and IGF-1 (66.6 ± 7.51 vs 91.4 ± 8.97 ng/ml) than LC fetuses. While most of the observed differences occurred between LC and LL pregnancies, LC fetuses tended (P ≤ 0.10) to have greater UmV and UmA pCO2 than C fetuses. Furthermore, the UmV:UmA O2 content gradient tended to be greater (5.02 ± 0.43 vs 3.41 ± 0.47; P ≤ 0.10) in C than LL fetuses. UmA placental lactogen also tended to be greater (46.6 ± 4.40 vs 31.1 ± 4.69 ng/ml; P ≤ 0.10) in LL than C fetuses. These data suggest that in twin pregnancies, maternal undernutrition followed by realimentation induces a different fetal outcome compared with continuous nutrient restriction, and both may differ physiologically from control fed pregnancies.

      PubDate: 2014-09-20T08:59:19Z
  • Creating leptin-like biofunctions by active immunization against cLEPR in
           growing chickens
    • Abstract: Publication date: Available online 16 September 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.M. Lei , S.Q. Wu , X.B. Shao , X.W. Li , Z. Chen , S.J. Ying , Z.D. Shi
      In this study, immunization against chicken leptin receptor (cLEPR) extracellular domain (ECD) was applied to investigate leptin regulation and LEPR biofunction in growing chicken pullets. A recombinant protein (cLEPR ECD) based on the cLEPR cDNA sequence corresponding to the 582nd to 796th amino acid residues of cLEPR mature peptide was prepared and used as antigen. Immunization against cLEPR ECD in growing chickens increased anti-cLEPR ECD antibody titers in blood, enhanced proportions of phosphorylated janus kinase 2 (JAK2), and served as signal transducer and activator of transcription 3 (STAT3) protein in liver tissue. Chicken live weight gain and abdominal fat mass were significantly decreased (p < 0.05), but feed intake was stimulated by cLEPR ECD immunization (p < 0.05). The treatment also up-regulated the gene expression levels of lepR, AMP-activated protein kinase (AMPK), acetyl CoA carboxylase-2 (ACC2), and uncoupling protein 3 (UCP3) in liver, abdominal fat, and breast muscle (p < 0.05) but decreased fasn expression levels (p < 0.01). Apart from that of lepR, the expressions of appetite-regulating genes, such as orexigenic genes, agouti-related peptide (AgRP), and neuropeptide Y (NPY), were up-regulated (p < 0.01), whereas the anorexigenic gene Proopiomelanocortin (POMC) was down-regulated in the hypothalamic tissue of cLEPR-immunized pullets (p < 0.01). Blood concentrations of metabolic molecules, such as glucose, triglycerides, and very-low-density lipoprotein (VLDL), were significantly decreased in cLEPR-immunized pullets, but those of cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) increased. These results demonstrate that antibodies to membrane proximal cLEPR ECD enhance cLEPR signal transduction, which stimulates metabolism and reduces fat deposition in chickens.

      PubDate: 2014-09-20T08:59:19Z
  • Editorial Board
    • Abstract: Publication date: October 2014
      Source:Domestic Animal Endocrinology, Volume 49

      PubDate: 2014-09-06T03:25:23Z
  • Contents
    • Abstract: Publication date: October 2014
      Source:Domestic Animal Endocrinology, Volume 49

      PubDate: 2014-09-06T03:25:23Z
  • Maternal insulin sensitivity in mid pregnancy does not determine birth
           weight after embryo transfer between large and small breed sheep
    • Abstract: Publication date: Available online 28 August 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.H. Oliver , A.L. Jaquiery , P.R. Kenyon , S.J. Pain , C.M. Jenkinson , H.T. Blair , J.G.B. Derraik , F.H. Bloomfield
      Embryo transfer of large sheep breed embryos (Suffolk) into small breed ewes (Cheviot) constrains birth size, but the maternal factors influencing fetal growth restriction are unknown. We hypothesised that reciprocal embryo transfer crosses between breeds of divergent size would affect pregnancy-related development of maternal insulin resistance in mid-gestation, thereby influencing fetal growth. Following superovulation, embryos were surgically collected 6 d post-mating and transferred to recipients on the same day. Between- and within-breed transfers were performed. Between 60 and 70 d of pregnancy overnight-fasted ewes underwent hyperinsulinaemic-euglycaemic clamps for assessment of insulin sensitivity. Maternal insulin sensitivity did not vary with transferred lamb breed. Overall, Cheviot ewes tended to have higher fasting glucose (P = 0.068), fasting insulin (P = 0.052), and steady state glucose (P = 0.065) concentrations than Suffolk ewes at the stage of pregnancy studied. As expected, transferred between-breed Suffolk lambs were born lighter (P = 0.014) and transferred between-breed Cheviot lambs tended to be heavier at birth (P = 0.056) than respective lambs transferred within-breed. Mid-gestation insulin sensitivity does not appear to be a major factor constraining growth of large breed sheep fetus transferred into smaller breed or a factor in releasing constraint in growth of a small breed fetus within a larger breed ewe. However, as embryo size is already different between transferred groups by 19 d, factors other than maternal gestational insulin resistance may determine fetal growth in this embryo transfer paradigm.

      PubDate: 2014-09-02T02:47:35Z
  • Effects of oral butyrate application on insulin signaling in various
           tissues of chickens
    • Abstract: Publication date: Available online 7 August 2014
      Source:Domestic Animal Endocrinology
      Author(s): G. Mátis , A. Kulcsár , V. Turowski , H. Fébel , Zs. Neogrády , K. Huber
      The influence of butyrate on insulin signaling in chickens was studied because butyrate is produced during microbial fermentation in the large intestine of birds and butyrate is widely used as a feed additive in animal production. Ross 308 broiler chickens received a daily intra-ingluvial bolus of sodium butyrate (0.25 g/kg BW) on d 20-24 of life (n = 10). Plasma butyrate concentration increased after receiving oral butyrate treatment (P < 0.001). Oral butyrate application was associated with decreased protein expression of insulin receptor β subunit (IRβ) in liver (P = 0.008) and both abdominal (P = 0.003) and subcutaneous adipose tissue (P < 0.001), but with elevated IRβ expression in muscle (P = 0.045), assessed by Western blotting. The quantity of hepatic phosphatidyl-inositol-3-kinase (PI3K) was reduced in the butyrate-treated group (P = 0.007), further, mammalian target of rapamycin (mTOR) was down-regulated by butyrate in liver (P < 0.001) and subcutaneous adipose tissue (P = 0.038). Oral butyrate application provoked reduced systemic insulin sensitivity in chickens, indicated by elevated fasting blood glucose and subsequently, insulin level. However, responses of insulin signaling cascade to butyrate were tissue-specific suggesting that butyrate could act on glucose shifting among tissues by selectively increasing the glucose uptake of skeletal muscle via IRβ up-regulation.

      PubDate: 2014-08-07T18:33:58Z
  • Pituitary pars intermedia dysfunction does not necessarily impair insulin
           sensitivity in old horses.
    • Abstract: Publication date: Available online 1 August 2014
      Source:Domestic Animal Endocrinology
      Author(s): L.M. Mastro , A.A. Adams , K.L. Urschel
      Equine pituitary pars intermedia dysfunction (PPID) has been associated with reduced insulin sensitivity in comparison to younger adult horses; however, the difference in insulin sensitivity between horses with PPID and aged-matched controls has not been well characterized. The objective of the study was to determine if aged horses with PPID had reduced insulin sensitivity and alterations in the insulin-mediated signaling pathways in the skeletal muscle when compared to healthy aged horses. Isoglycemic hyperinsulinemic clamp procedures were conducted in twelve horses that were classified as either PPID (n=6; age 25.0 ± 2.5 yr; mean ± SD) or non-PPID, aged-matched controls (Control) (n = 6; age: 25.7 ± 2.0 yr). Blood samples were taken prior to and during the clamp procedures to measure plasma glucose, insulin and amino acid concentrations and two muscle biopsies were collected from the gluteus medius muscle, one in the basal state and a second at the end of the clamp procedure (insulin-stimulated state). Plasma insulin concentrations increased ∼9-fold during the clamp compared to basal conditions (P < 0.001) in both groups. During the last 30 min of the clamp, the rate of glucose infusion required to maintain isoglycemia in horses with PPID was similar to that in the Control horses (P = 0.67). The plasma concentrations of most indispensible amino acids were lower in the insulin-stimulated state than the basal state (P < 0.05). PPID status did not have an effect on the activation of factors associated with protein synthesis and breakdown; however, factors associated with protein synthesis had increased phosphorylation in the insulin-stimulated state, compared to basal. The results from this study provide evidence that PPID is not always associated with impairments in insulin sensitivity.

      PubDate: 2014-08-03T17:00:57Z
  • Metabolic determinants of body weight after cats were fed a
           low-carbohydrate high-protein diet or a high-carbohydrate low-protein diet
           ad libitum for 8 wk
    • Abstract: Publication date: Available online 14 June 2014
      Source:Domestic Animal Endocrinology
      Author(s): M. Coradini , J.S. Rand , J.M. Morton , J.M. Rawlings
      Overweight and obese conditions are common in cats and are associated with the development of a number of diseases. Knowledge of metabolic determinants and predictors of weight gain may enable better preventative strategies for obesity in cats. Lean, healthy cats were fed either a low-carbohydrate high-protein diet (n 16) or a high-carbohydrate low-protein (n 16) diet ad libitum for 8 wk. Potential determinants and predictors of final body weight assessed were body fat and lean masses, energy required for maintenance, energy requirements above maintenance for each kilogram of weight gain, insulin sensitivity index, fasting, mean 24-h and peak plasma glucose, insulin, and leptin concentrations, and fasting and mean 24-h serum adiponectin concentrations. In cats that fed the low-carbohydrate high-protein diet, after adjusting for initial body weight, those with higher energy requirements for weight gain and higher fasting glucose concentration had higher final body weights (P ≤ 0.01). Predicted final body weights using initial body weight, fasting glucose, and mean 24-h insulin concentrations (partial R 2 37.3%) were imprecise. An equation using just initial body weight and fasting glucose concentration would be of more practical value, but was marginally less precise. In cats that fed the high-carbohydrate low-protein diet, those with lower fasting leptin concentration initially had higher final body weights (P = 0.01). Predicted final body weights using initial body weight, energy requirements for maintenance, total body fat percentage, and fasting leptin concentration (partial R 2 39.2%) were reasonably precise. Further studies are warranted to confirm these findings and to improve the precision of predicted final body weights.

      PubDate: 2014-07-27T15:30:21Z
  • Characterization of proopiomelanocortin in the snakeskin gourami
           (Trichopodus pectoralis) and its expression in relation to food intake
    • Abstract: Publication date: Available online 30 June 2014
      Source:Domestic Animal Endocrinology
      Author(s): S. Booanuntanasarn , A. Jangprai , G. Yoshizaki
      Proopiomelanocortin (POMC) is the precursor of several hormones involved in physiological systems including feed intake. The snakeskin gourami (Trichopodus pectoralis) POMC complementary DNA (TpPOMC) was cloned and characterized. Phylogenetic analysis showed that TpPOMC was clustered in a major POMC lineage in fish. Analysis of the K a to K s ratios for the entire POMC sequence and for each hormonal segment suggested that different POMC-derived peptide segments were subject to different evolutionary pressures. High expression level of TpPOMC was observed in all brain regions, with the highest levels in the diencephalon and pituitary gland. In situ hybridization also revealed that TpPOMC-expressing cells are distributed in discrete brain regions. The transcription level of TpPOMC was also found at moderate levels in several peripheral tissues, including gills, liver, head kidney, trunk kidney, stomach, intestine, spleen, ovary and testis, and at a low level in muscle. The expression level of TpPOMC was evaluated in each brain region (telencephalon, mesencephalon, metencephalon, and diencephalon together with the pituitary gland) at 1 h before the first and the last meals of the day and compared with expression levels at a time interval between the first and the last meals of the day. Low expression levels of TpPOMC were found at 1 h before the last meal of the day (P < 0.05). These finding suggest that decreased POMC expression level may lead to reduced melanocyte-stimulating hormones, which may in part be responsible for stimulating food intake. The effect of short-term fasting (24 h) on TpPOMC expression level in each brain region was also investigated. In telencephalon and diencephalon together with the pituitary gland, TpPOMC messenger RNA reached a nadir at 12 h of fasting, whereas TpPOMC transcript showed a nadir at 6 h of fasting in metencephalon and mesencephalon. A peak of TpPOMC level was observed at 18 h of fasting in metencephalon and diencephalon together with the pituitary gland. These findings suggest that TpPOMC expression is affected by nutritional status.

      PubDate: 2014-07-27T15:30:21Z
  • Expression of the vascular endothelial growth factor receptor system in
           porcine oviducts after induction of ovulation and superovulation
    • Abstract: Publication date: Available online 1 July 2014
      Source:Domestic Animal Endocrinology
      Author(s): I. Małysz-Cymborska , A. Andronowska
      This study was performed to determine the influence of insemination as well as treatment with hCG (human chorionic gonadotropin) and eCG (equine chorionic gonadotropin) on expression of the VEGF system in porcine oviducts. In the first experiment, ten gilts were assigned to two groups: cyclic (treated with PBS; n=5) and inseminated (n=5). In experiment II, fifteen gilts were assigned into three groups: inseminated (control; n=5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n=5) and superovulated /inseminated (1500 IU eCG, 1000 IU hCG; n=5). Oviducts (isthmus and ampulla) were collected three days after PBS treatment (experiment I) or insemination. Blood samples were collected during slaughter for E2 (oestradiol) and P4 (progesterone) analysis. Levels of mRNA of the VEGF system were analyzed by real-time PCR, protein by Western blot and E2 and P4 using RIA. Insemination by itself decreased VEGF 120 mRNA expression and VEGF-A protein level in the oviductal isthmus (P < 0.05), but did not alter VEGF 164 mRNA. Expression of Flt-1 (c-fms-like tyrosine kinase VEGFR-1) mRNA increased in the isthmus of inseminated relative to cyclic gilts (P < 0.05), whereas KDR (fetal liver kinase-1 VEGFR-2) mRNA levels decreased in both the oviductal isthmus (P < 0.05) and ampulla (P < 0.001). Superovulation decreased VEGF 120 and VEGF 164 mRNA expression in the isthmus, compared with the inseminated group (P < 0.05), and lowered protein levels of VEGF-A in the isthmus of both stimulated groups (P < 0.001). Expression of Flt-1 mRNA was affected by hCG and eCG treatment in both gonadotropin-stimulated groups in the isthmus as well as in the ampulla (P < 0.001) and protein levels in the ampulla of superovulated gilts (P < 0.05). Protein levels of KDR were reduced in the oviductal ampulla of gilts in both the induced ovulation and superovulated groups of (P < 0.05). The concentrations of both E2 and P4 increased significantly in superovulated group of gilts (P < 0.01; P < 0.05 for E2 and P4 respectively). Our study showed that insemination alone as well as ovarian stimulation affected the mRNA and protein profiles of the VEGF system in the porcine oviduct. Disrupted VEGF system expression may be crucial to many events occurring during the periovulatory period and consequently could lead to deprivation of VEGF-dependent factors that are necessary for proper fertilization, gamete transport and embryo development.

      PubDate: 2014-07-27T15:30:21Z
  • Neonatal glucocorticoid overexposure programs pituitary-adrenal function
           in ponies
    • Abstract: Publication date: Available online 3 July 2014
      Source:Domestic Animal Endocrinology
      Author(s): J.K. Jellyman , O.A. Valenzuela , V.L. Allen , A.J. Forhead , N.B. Holdstock , A.L. Fowden
      The present study tested the hypothesis that overexposure to endogenous glucocorticoids in neonatal life alters the reactivity of the hypothalamic-pituitary-adrenal (HPA) axis in ponies at 1 and 2 yr of age. Newborn foals received saline (0.9% NaCl, n = 8, control) or long-acting adrenocorticotropic hormone (ACTH1-24) (Depot Synacthen 0.125 mg intramuscularly twice daily, n = 9) for 5 d after birth to raise cortisol concentrations 5- to 6-fold. At 1 and 2 yr of age, HPA axis function was assessed by bolus administration of short-acting ACTH1-24 (1 μg/kg intravenous) and insulin (0.5 U/kg intravenous) to induce hypoglycemic on separate days. Arterial blood samples were taken at 5 to 30-min intervals before and after drug administration to measure plasma ACTH and/or cortisol concentrations. There were no differences in the basal plasma ACTH or cortisol concentrations or in the cortisol response to exogenous ACTH1-24 with neonatal treatment or age. At 1 and 2 yr of age, the increment in plasma ACTH but not cortisol at 60 min in response to insulin-induced hypoglycemia was greater in ponies treated neonatally with ACTH than saline (P < 0.05). Neonatal cortisol overexposure induced by neonatal ACTH treatment, therefore, alters functioning of the HPA axis in adult ponies.

      PubDate: 2014-07-27T15:30:21Z
  • Temporal dynamic of adrenocortical and gonadal photoresponsiveness in male
           Japanese quail exposed to short days
    • Abstract: Publication date: Available online 5 July 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.F. Dominchin , R.H. Marin , R. Palme , J.M. Busso
      The study evaluated whether different short-term endocrine testicular and adrenocortical responses to short photoperiod exposure can persist over time and particularly when birds exhibit spontaneous cloacal gland recovery. At 11 wk of age, 33 male Japanese quail exposed to long photoperiod were switched to short photoperiod (8L:16D). Another group of males was kept under long photoperiod (n = 11). After 5 wk of short photoperiod exposure, quail were classified as nonresponsive or responsive to short photoperiod, depending on whether the cloacal gland volume was above or below 1,000 mm3 and with or without foam production, respectively. Since 11 wk of age and during a 20-wk period, droppings of all quail were collected to determine corticosterone and androgen metabolites (AM) by enzyme immunoassays. Cloacal gland volume was also determined weekly. Both short photoperiod nonresponsive (SD-NR) and responsive quail showed overall significantly lower (P < 0.01) AM values (518.8 ± 11.9 and 248.6 ± 17.1 ng/g, respectively) than quail (LD) that remained under long photoperiod (814.3 ± 24.1 ng/g). However, nonresponsive quail showed a significantly smaller reduction in their AM levels than their responsive counterparts. During the first 6 wk of short photoperiod exposure, SD-NR quail showed similar corticosterone metabolites values than LD quail. Corticosterone metabolite profiles changed from 7 wk of short photoperiod exposure onward, with photoperiodic differences (P < 0.01) persisting up to the end of study (LD: 228.9 ± 22.4 > SD-NR: 133.1 ± 15.5 > short photoperiod responsive: 61.6 ± 17.9 ng/g, respectively). Testicular and adrenocortical glands showed different degrees of activity associated with cloacal gland photoresponsiveness to short photoperiod manipulation. Our findings suggest long-term effects of short photoperiod, both in the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-adrenocortical axis activity of quail, including males that exhibited spontaneous cloacal gland recovery.

      PubDate: 2014-07-27T15:30:21Z
  • Plasma anti-Mullerian hormone: an endocrine marker for in vitro embryo
           production from Bos taurus and Bos indicus donors
    • Abstract: Publication date: Available online 22 July 2014
      Source:Domestic Animal Endocrinology
      Author(s): B.M. Guerreiro , E.O.S. Batista , L.M. Vieira , M.F. Sá Filho , C.A. Rodrigues , A. Castro Netto , C.R.A. Silveira , B.M. Bayeux , E.A.R. Dias , F.M. Monteiro , M. Accorsi , R.N.V.R. Lopes , P.S. Baruselli
      The aim of this study was to evaluate the association between plasma anti-Mullerian hormone (AMH) concentration and in vitro embryo production (IVP) from Bos taurus (Holstein) and Bos indicus (Nelore) donors. A total of 59 Holstein (15 prepubertal heifers aged 8-10 mo, 15 cyclic heifers aged 12-14 mo, 14 lactating cows and 15 non-lactating cows) and 34 Nelore (12 prepubertal heifers aged 10-11 mo, 10 prepubertal heifers aged 21-23 mo and 12 cyclic heifers aged 24-26 mo) females were enrolled. All females underwent an ovum pick–up (OPU), without previous synchronization of the follicular wave, and IVP procedure. Immediately before the OPU procedure, blood samples were collected for subsequent AMH determination. A positive correlation was observed between the plasma AMH and number of in vitro embryos produced from Holstein (r = 0.36, P < 0.001) and Nelore (r = 0.50, P = 0.003) donors. For additional analyses, donors within each genotype were classified into 1 of 2 AMH categories (low or high) according to the average AMH concentration for each genotype. The results revealed that females classified as having high AMH presented a greater number of visible aspirated follicles (Holstein: 20.9 ± 1.5 vs. 13.6 ± 0.9, P < 0.0001; Nelore: 54.3 ± 6.1 vs. 18.6 ± 2.1, P < 0.0001) and a greater number of recovered cumulus-oocyte complexes (COC; Holstein: 17.3 ± 1.5 vs. 9.0 ± 0.9, P < 0.0001; Nelore: 45.3 ± 6.4 vs. 13.4 ± 1.7, P < 0.0001). However, there was no difference in the blastocyst production rate (Holstein: 20.6 ± 4.0 % vs. 19.8 ± 4.2 %, P = 0.60; Nelore: 33.7 ± 6.5 % vs. 27.4 ± 5.5 %; P = 0.41, high and low AMH, respectively). Moreover, donors classified as having high AMH yielded a greater number of embryos produced per OPU (Holstein: 3.0 ± 0.7, Nelore: 7.0 ± 1.7) compared to those classified as having low AMH (Holstein: 1.2 ± 0.3, P = 0.04; Nelore: 2.2 ± 0.5, P = 0.007). In conclusion, even though the plasma AMH concentration did not alter the ability of the COC to reach the blastocyst stage, the AMH concentration in plasma can be an accurate endocrine marker for the in vitro embryo yield from either Bos taurus (Holstein) or Bos indicus (Nelore) donors. Therefore, AMH is a promising tool to enhance the overall efficiency of OPU-IVP programs in the field as a selective criterion for high embryo producing donors.

      PubDate: 2014-07-27T15:30:21Z
  • The effects of parity, litter size, physiological state and milking
           frequency on the metabolic profile of Lacaune dairy ewes
    • Abstract: Publication date: Available online 23 July 2014
      Source:Domestic Animal Endocrinology
      Author(s): E. González-García , A. Tesniere , S. Camous , F. Bocquier , F. Barillet , P. Hassoun
      Effects of parity (primiparous, PRIM vs. multiparous, MULT) and litter size (singletons, SING vs. twins, TWIN) on metabolic profiles from 1 wk before lambing to the end of lactation were studied in 48 Lacaune dairy ewes reared in confinement during most of the year and grazed on improved pastures at the end of lactation (summer). Another group of 48 ewes was incorporated during the milking period (i.e., from 1 wk after weaning), to measure the effects of milking frequency (one vs. two milkings per day) on intake, milk production and composition, and body energy usage. Thus, in a 2 × 2 × 2 factorial design, ewes (n = 96) were allocated to homogeneous groups according to body weight (BW) and body condition score (BCS) and were monitored from late pregnancy to late lactation as a function of parity (PAR; PRIM, n = 48; MULT, n = 48), litter size (LSi) (SING, n = 40; TWINS, n = 56) and daily milking frequency (FREQ; milked once, ONE; n = 48; or twice, TWO; n = 48). Individual BW, BCS, plasma metabolites and metabolic hormones were measured regularly (i.e., 9 consecutive sampling dates). The BW was higher in MULT but no differences due to LSi or FREQ were detected at the intra-parity group level. The BCS was higher in MULT and in ewes with SING throughout the experiment. The latter was related to the demands for body reserves mobilization, as expressed by higher non-esterified fatty acids (NEFA) and β-hydroxybutyrate (ß-OHB) concentrations in ewes with TWIN from late pregnancy to weaning (35 d postpartum) in both PRIM and MULT ewes. This was consistent with higher insulin in MULT and higher triiodothyronine (T3), leptin and insulin-like growth factor 1 (IGF-1) in ewes with SING during this period. Differences in energy balance due to FREQ were evident after interpretation of plasma NEFA, glucose, insulin and leptin concentration during the milking period. At similar feed intakes, ewes in ONE were in positive balance with regard to TWO. Overall, clear effects of PAR, LSi, physiological states and FREQ on metabolic profiles were found, due to differences in nutrient partitioning when combining these experimental factors. Without considering FREQ, changes in metabolic measures in milking period were marginal compared with the periparturient adjustments performed until weaning to compensate energy deficiencies.

      PubDate: 2014-07-27T15:30:21Z
  • Vascular endothelial growth factor A improves quality of matured porcine
           oocytes and developing parthenotes
    • Abstract: Publication date: October 2014
      Source:Domestic Animal Endocrinology, Volume 49
      Author(s): M. Kere , C. Siriboon , J.W. Liao , N.W. Lo , H.I. Chiang , Y.K. Fan , J.P. Kastelic , J.C. Ju
      Vascular endothelial growth factor is a multipotent angiogenic factor implicated in cell survival and proliferation. The objective was to determine effects of exogenous recombinant human VEGFA (or VEGFA165) in culture media on porcine oocyte maturation and parthenote development. Adding 5 ng/mL VEGFA to the culture medium improved the maturation rate of denuded oocytes (P < 0.05), although 5, 50, or 500 ng/mL did not significantly affect nuclear maturation of oocytes. Parthenotes from oocytes cultured either in in vitro maturation or in vitro culture medium supplemented with 5 or 50 ng/mL VEGFA had an improved blastocyst rate and increased total numbers of cells (P < 0.05). Moreover, those treated with 5 ng/mL of VEGFA had a higher hatched blastocyst rate (average of 121 cells per blastocyst). All VEGFA-treated oocytes had reduced apoptotic indices (P < 0.05), except for those with a higher dose (500 ng/mL) of VEGFA which had more apoptotic cells (P < 0.05). Adding 5 ng/mL VEGFA to oocytes during the last 22 h of in vitro maturation improved (P < 0.05) blastocyst rates and total numbers of cells, with reduced apoptosis indices similar to that of long-term (44 h) culture. Furthermore, Axitinib (VEGFR inhibitor) reversed the effects of VEGFA on parthenote development (P < 0.05). Follicular fluids from medium (2–6 mm) to large (>6 mm) follicles contained 5.3 and 7.0 ng/mL vascular endothelial growth factor protein, respectively, higher (P < 0.05) than concentrations in small (<2 mm) follicles (0.4 ng/mL). Also, VEGFA and its receptor (VEGFR-2) were detected (immunohistochemistry) in growing follicles and developing blastocysts. In addition, VEGFA inhibited caspase-3 activation in matured oocytes (P < 0.05). In conclusion, this is apparently the first report that VEGFA has proliferative and cytoprotective roles in maturing porcine oocytes and parthenotes. Furthermore, an optimal VEGFA concentration promoted porcine oocyte maturation and subsequent development.

      PubDate: 2014-07-27T15:30:21Z
  • Editorial Board
    • Abstract: Publication date: July 2014
      Source:Domestic Animal Endocrinology, Volume 48

      PubDate: 2014-06-07T17:41:12Z
  • Contents
    • Abstract: Publication date: July 2014
      Source:Domestic Animal Endocrinology, Volume 48

      PubDate: 2014-06-07T17:41:12Z
  • Poor maternal nutrition during gestation in sheep reduces circulating
           concentrations of insulin-like growth factor (IGF)-I and IGF binding
           protein (IGFBP)-3 in offspring
    • Abstract: Publication date: Available online 28 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.L. Hoffman , M.A. Rokosa , S.A. Zinn , T.A. Hoagland , K.E. Govoni
      To determine if poor maternal nutrition alters growth, body composition, circulating growth factors and expression of genes involved in the development of muscle and adipose of offspring, 24 Dorset and Shropshire ewes were fed either 100% (control-fed), 60% (restricted-fed), or 126% (over-fed) of NRC requirements. Diets began at day 116 ± 6 of gestation until parturition. At parturition, one lamb from each control-fed (CON), restricted-fed (RES) and over-fed (OVER) ewe was necropsied within 24 h of birth (1 d; n = 3/treatment) or reared on a control diet for 3 mo (CON = 5; RES = 5; OVER = 3/treatment) and then euthanized. Body weights and blood samples were collected from lambs from 1 d to 3 mo. Organ weights, backfat thickness, loin eye area, and tissue samples (quadriceps, adipose, and liver) were collected at 1 d and 3 mo of age. The RES lambs weighed 16% less than CON (P = 0.01) between 1 d and 3 mo of age. In RES, there was a tendency for reduced heart girth at 1 d and 3 mo (P < 0.07) and backfat was reduced 36% at 3 mo (P = 0.03). Heart weight was 30% greater in OVER at 1 d when compared with RES lambs (P = 0.02). Serum IGF-I and IGFBP-3 were reduced in RES and OVER lambs (P < 0.05). Leptin tended to be greater in OVER lambs compared with CON at 1 d and 3 mo (P ≤ 0.08). Triiodothyronine was reduced in RES at 1 d (P = 0.05) and triglycerides tended to be greater in OVER at 3 mo (P = 0.07). In liver, there was a tendency for increased expression of IGF-I in OVER (P = 0.06) and decreased IGFBP-3 in RES (P = 0.09) compared with CON lambs at 1 d. In adipose tissue, adiponectin expression was decreased in RES (P = 0.05) at 3 mo. At 1 d of age, muscle expression of IGF-I tended to increase in RES (P = 0.06). In conclusion, poor maternal nutrition during gestation reduced growth rate in offspring which may be due to reduced circulating IGF-I and IGFBP-3 and decreased expression of IGFBP-3 in the liver.

      PubDate: 2014-06-01T14:47:11Z
  • Hepatic steroid metabolizing enzyme activity during early, mid, and late
           bovine pregnancy
    • Abstract: Publication date: Available online 29 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): C.G. Hart , L.E. Camacho , K.C. Swanson , K.A. Vonnahme , C.O. Lemley
      The objective was to examine hepatic steroid inactivating enzymes throughout gestation and to determine the effect of early to mid-gestation maternal nutrient restriction followed by realimentation on the activity of these enzymes. On day 30 of gestation, cows were assigned to dietary treatments: control (CON; 100% National Research Council; n = 18) and restricted (RES; 60% National Research Council; n = 30). On day 85 cows were slaughtered (CON, n = 6 and RES, n = 6), remained on control (CC; n = 12) and restricted (RR; n = 12), or were realimented to control (RC; n = 11). On day 140 cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remained on control (CCC, n = 6; RCC, n = 5), or were realimented to control (RRC, n = 6). On day 254 all remaining cows were slaughtered. Jugular blood samples were collected prior to slaughter for steroid analysis. At slaughter maternal liver samples were collected for hepatic enzyme activity analysis. Activity of cytochrome P450 3A (CYP3A) decreased (P = 0.05) from mid- to late-gestation. Peroxisome proliferator-activated receptor alpha (PPARα) DNA binding activity was increased (P < 0.01) on day 140 and 254 of gestation versus day 85. Concentrations of estradiol-17β (E2) increased (P < 0.01) as gestation proceeded, while progesterone concentrations (P4) tended to increase (P = 0.06) from mid- to late-gestation. Activity of cytochrome P450 1A (CYP1A) and 2C (CYP2C) were decreased (P < 0.05) in nutrient restricted cows versus control, while concentrations of E2 were increased (P < 0.05) in nutrient restricted cows versus control. A longer period of nutrient realimentation from mid- to late-gestation increased (P < 0.05) aldo-keto reductase 1C (AKR1C) activity and decreased (P < 0.05) P4 concentrations compared to the shorter period of nutrient realimentation. In addition, significant negative correlations were observed for CYP3A activity versus E2 (r2 = -0.30; P < 0.05) and AKR1C activity versus P4 (r2 = -0.29; P < 0.05). The current study implicates hepatic steroid inactivation in the partial modulation of peripheral concentrations of E2 and P4 during gestation.

      PubDate: 2014-06-01T14:47:11Z
  • Pro- and anti-inflammatory mediators change leukotriene (LT)B4 and LTC4
           synthesis and secretion in an inflamed porcine endometrium
    • Abstract: Publication date: Available online 21 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): J. Czarzasta , A. Andronowska , B. Jana
      We studied the effect of lipopolysaccharide (LPS), pro- (tumor necrosis factor-α /TNF-α/, IL-1β) and anti (IL-4, IL-10)-inflammatory cytokines on leukotriene (LT)A4 hydrolase (LTAH) and LTC4 synthase (LTCS) protein expression in, and LTB4 and LTC4 secretion from, an inflamed porcine endometrium. On day 3 of the estrous cycle (day 0 of the study), 50 mL of either saline or Escherichia coli suspension (109 colony-forming units/mL) were injected into each uterine horn of gilts (n = 12 per group). Endometrial explants, obtained eight and sixteen days later, were incubated for 24 h with LPS (10 or 100 ng/mL of medium), TNF-α, IL-1β, IL-4 and IL-10 (each cytokine: 1 or 10 ng/mL of medium). Although acute endometritis developed in all bacteria-inoculated gilts, a severe form of acute endometritis was diagnosed more often on day 8 of the study than on day 16. The amount of the LTAH protein in the inflamed endometrium on day 8 was greater after applying the lower dose of TNF-α (P < 0.001) and both doses of IL-1β (P < 0.001) and IL-4 (1 ng: P < 0.01; 10 ng: P < 0.001) than in the saline-treated uteri. A similar situation was observed in the case of the inflamed tissue on day 16 in response to LPS (100 ng: P < 0.01), TNF-α (10 ng: P < 0.05) and IL-4 (1 ng: P < 0.001). The content of LTCS in the inflamed endometrium on day 8 was reduced by LPS (100 ng: P < 0.05), IL-1β (10 ng: P < 0.05), IL-4 (1 and 10 ng: P < 0.05) and IL-10 (1 ng: P < 0.01), but increased after the application of LPS (100 ng: P < 0.05) as well as TNF-α (P < 0.001), IL-1β and IL-4 (1 ng: P < 0.05; 10 ng: P < 0.001) on day 16. On day 8, endometrial secretion of LTB4 from the saline- and E. coli-injected organs was similar in response to all of the used mediators. On the other hand, the contents of LTB4 in the medium decreased after incubating the inflamed tissues from day 16 with TNF-α (1 ng: P < 0.05; 10 ng: P < 0.01), IL-1β (1 ng: P < 0.01) and IL-10 (10 ng: P < 0.05) as compared to the saline-treated ones. Secretion of LTC4 from the inflamed uteri on day 8 was elevated by the lower doses of TNF-α (P < 0.01) and IL-10 (P < 0.05), while on day 16, such an effect occurred in response to the higher doses of IL-4 (P < 0.01) and IL-10 (P < 0.05). The obtained results show that pro- and anti-inflammatory mediators participate in the synthesis/secretion of LTs from an inflamed porcine endometrium. Our data suggest that inflammatory mediators may indirectly affect the processes regulated by LTs by influencing LT production.

      PubDate: 2014-05-25T09:22:59Z
  • Role of G protein-coupled estrogen receptor -1, matrix metalloproteinases
           2 and 9, and heparin binding epidermal growth factor-like growth factor in
           Estradiol-17β-stimulated bovine satellite cell proliferation
    • Abstract: Publication date: Available online 9 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): E. Kamanga-Sollo , K.J. Thornton , M.E. White , W.R. Dayton
      In feedlot steers, estradiol-17β (E2) and combined E2 and trenbolone acetate (TBA) (a testosterone analog) implants enhance rate and efficiency of muscle growth; and, consequently, these compounds are widely used as growth promoters. Although the positive effects of E2 on rate and efficiency of bovine muscle growth are well established, the mechanisms involved in these effects are not well understood. Combined E2/TBA implants result in significantly increased muscle satellite cell number in feedlot steers. Additionally, E2 treatment stimulates proliferation of cultured bovine satellite cells (BSC). Studies in nonmuscle cells have shown that binding of E2 to G protein-coupled estrogen receptor (GPER)-1 results in activation of matrix metalloproteinases 2 and 9 (MMP2/9) resulting in proteolytic release of heparin binding epidermal growth factor-like growth factor (hbEGF) from the cell surface. Released hbEGF binds to and activates the epidermal growth factor receptor (EGFR) resulting in increased proliferation. In order to assess if GPER-1, MMP2/9 and/or hbEGF are involved in the mechanism of E2-stimulated BSC proliferation, we have examined the effects of G36 (a specific inhibitor of GPER-1), CRM197 (a specific inhibitor of hbEGF), and MMP-2/MMP-9 Inhibitor II (an inhibitor of MMP2/9 activity) on E2-stimulated BSC proliferation. Inhibition of GPER-1, MMP2/9 or hbEGF suppresses E2-stimulated BSC proliferation (P < 0.001) suggesting that all of these are required in order for E2 to stimulate BSC proliferation. These results strongly suggest that E2 may stimulate BSC proliferation by binding to GPER-1 resulting in MMP2/9-catalyzed release of cell membrane-bound hbEGF and subsequent activation of EGFR by binding of released hbEGF.

      PubDate: 2014-05-10T04:28:50Z
  • Effects of sitagliptin on plasma incretin concentrations after glucose
           administration through an esophagostomy tube or feeding in healthy cats
    • Abstract: Publication date: Available online 9 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): N. Nishii , S. Takashima , A. Iguchi , Y. Murahata , A. Matsuu , Y. Hikasa , H. Kitagawa
      We investigated the effect of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, on plasma incretin concentrations after glucose administration through an esophagostomy tube or feeding in healthy cats. Six cats were used for the glucose administration experiment and five cats were used for the feeding experiment. Glucose administration through an esophagostomy tube increased plasma glucagon-like peptide-1 (GLP-1) concentrations by 6-fold, whereas plasma glucose-dependent insulinotropic polypeptide (GIP) concentrations did not change. Feeding increased both plasma GLP-1 concentrations by 1.5-fold and GIP concentrations by 4.6-fold. Sitagliptin was administered through an esophagosomy tube (25 and 50 mg/cat) in the glucose administration experiment and orally (25 mg/cat) in the feeding experiment. Sitagliptin treatment potentiated the GLP-1 response to glucose by 1.5-fold (P < 0.05). In addition, postprandial plasma GLP-1 concentration was higher by 2-fold when sitagliptin was administered (P < 0.05). In contrast, administration of sitagliptin did not affect plasma GIP concentrations after glucose administration or feeding. Sitagliptin enhanced insulin secretion following glucose administration by 1.5-fold (P < 0.05); however, it did not influence the plasma glucose concentration. Furthermore, sitagliptin had no effect on the postprandial plasma glucose and insulin concentrations. In conclusion, this study provides no evidence that sitagliptin is beneficial for management of feline diabetes mellitus.

      PubDate: 2014-05-10T04:28:50Z
  • Is the mouse follicle culture a good model for the goat with respect to
           the development of preantral follicles in vitro'
    • Abstract: Publication date: Available online 9 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): R.M.P. Rocha , A.M.C.V. Alves , L.F. Lima , A.B.G. Duarte , R.N. Chaves , I.R. Brito , E.C. Costa , M.P. Bernuci , A.C.J.S. Rosa-e-Silva , M. Xu , A.P.R. Rodrigues , C.C. Campello , J.R. Figueiredo
      The present study evaluated the efficiency of using two culture media developed for mice and for goats in the in vitro preantral follicle culture of each species. Murine and caprine secondary follicles were cultured in vitro with human recombinant FSH (murine medium) or with bovine recombinant FSH in association with GH (caprine medium). The results showed that murine follicles cultured in caprine medium had lower (P<0.05) rates of follicular survival and growth, whereas for caprine follicles, these variables were not affected by the type of medium used (P>0.05). After in vitro maturation, a higher (P<0.05) number of oocytes that resumed meiosis were observed in the murine medium for both species. In contrast, only in the caprine species estradiol production was significantly superior when the caprine medium was used. Higher progesterone production was observed in the presence of the murine medium only for murine follicles (P<0.05). In conclusion, murine and caprine preantral follicles cultured under the same in vitro culture medium conditions respond differently; caprine oocytes grown in vitro in the presence of the murine medium show the greatest developmental competence among the tested combinations. Therefore, under the present experimental conditions, the mouse follicle culture has proved be a good model for the development of new culture media for caprine preantral follicles.

      PubDate: 2014-05-10T04:28:50Z
  • Sex differences in the expression of estrogen receptor-α within
           noradrenergic neurons in the sheep brainstem
    • Abstract: Publication date: Available online 2 May 2014
      Source:Domestic Animal Endocrinology
      Author(s): J.L. Rose , A.S. Hamlin , C.J. Scott
      In female sheep, high levels of estrogen exert a positive feedback action on GnRH secretion to stimulate a surge in LH secretion. Part of this action appears to be via brainstem noradrenergic neurons. By contrast, estrogen action in male sheep has a negative feedback action to inhibit GnRH and LH secretion. To investigate whether part of this sex difference is due to differences in estrogen action in the brainstem, we tested the hypothesis that the distribution of estrogen receptor-α (ERα) within noradrenergic neurons in the brainstem differs between rams and ewes. To determine the distribution of ERα we employed dual-label fluorescence immunohistochemistry for dopamine β-hydroxylase (DBH), as a marker for noradrenergic/adrenergic cells, and ERα. In the ventrolateral medulla (A1 region), most ERα –immunoreactive (-ir) cells were located in the caudal part of the nucleus. Overall there were more ERα-ir cells in rams than ewes, but the proportion of double labelled cells was did not differ between sexes. Much greater numbers of ERα –ir cells were found in the nucleus of the solitary tract (A2 region), but <10% were double labelled and there were no sex differences. The majority of ERα –labelled cells in this nucleus were located in the more rostral areas. ERα –labelled cells were found in several rostral brainstem regions but none of these were double-labelled and so were not quantified. Since there was no sex difference in the number of ERα –ir cells in the brainstem that were noradrenergic, the sex difference in the action of estrogen on gonadotropin secretion in sheep is unlikely to involve actions on brainstem noradrenergic cells.

      PubDate: 2014-05-04T22:45:49Z
  • Expression of steroidogenic factor 1 in canine cortisol-secreting
           adrenocortical tumors and normal adrenals
    • Abstract: Publication date: Available online 28 April 2014
      Source:Domestic Animal Endocrinology
      Author(s): S. Galac , M.M.J. Kool , M.F. van den Berg , J.A. Mol , H.S. Kooistra
      We report on a screening for the relative mRNA and protein expression of steroidogenic factor 1 (SF-1) in normal canine adrenals (n=10) and cortisol-secreting adrenocortical tumors (11 adenomas and 26 carcinomas). The relative mRNA expression of SF-1 was determined by quantitative RT-PCR analysis and revealed no differences between normal adrenals, adenomas, and carcinomas. Immunohistochemistry demonstrated SF-1 protein expression in a nuclear pattern throughout the normal adrenal cortex and a predominantly nuclear staining pattern in adrenocortical tumors. Of the 15 dogs available for follow up, 7 dogs developed hypercortisolism within 2.5 yr after adrenalectomy, with metastatic disease in 6 dogs and adrenocortical tumor regrowth in 1 dog. The relative SF-1 mRNA expression in dogs with early recurrence was greater (2.46-fold, P = 0.020) than in dogs in remission for at least 2.5 yr after adrenalectomy. In conclusion, we demonstrated the presence of SF-1 expression in normal canine adrenals and adrenocortical tumors. The high SF-1 mRNA expression in carcinomas with early recurrence might indicate its value as a prognostic marker, as well as its potential for therapeutic development.

      PubDate: 2014-04-29T16:36:34Z
  • Initiation of active immunization against testosterone during early
           puberty alters negative feedback regulation of the
           hypothalamic-pituitary-testicular axis in rabbits
    • Abstract: Publication date: Available online 12 April 2014
      Source:Domestic Animal Endocrinology
      Author(s): X.F. Han , W. Cheng , Z.Y. Chen , X.G. Du , X.H. Cao , X.Y. Zeng
      To investigate effects of anti-testosterone immunization, initiated during early puberty, on hypothalamic-pituitary-testicular feedback in rabbits, 16 early pubertal male rabbits were randomly allocated into two groups (n = 8), control or immunized against testosterone-3(O-carboxymethyl)oxime-BSA in Freund’s adjuvant at 4 mo of age (with a booster immunization 4 wk later). Blood samples (for antibody titers and hormone concentrations) were collected at 2- or 4-wk intervals after immunization. Compared to controls, anti-testosterone immunization triggered: a substantial and sustained antibody response (P < 0.01); increases in serum concentrations of LH and testosterone, and testis weight and volume (P < 0.05); hyperplasia of testicular interstitial tissue with clustered and hypertrophic Leydig cells; and greater (P < 0.05) enzyme protein and mRNA expression levels for testicular cholesterol side-chain cleavage cytochrome P-450, 17α-hydroxylase cytochrome P-450 and 3β-dydroxysteroid dehydrogenase. Furthermore, immunoneutralization of testosterone up-regulated mRNA expressions for genes in sex steroid negative feedback loops, including androgen receptor (AR), estrogen receptor alpha (ER-α), kisspeptin encoded gene (kiss-1) and kisspeptin receptor (GPR54) and GnRH in the hypothalamic arcuate nucleus, GnRH receptor and LH-β in pituitary, and AR, inhibin-α and βA subunits in testes (P < 0.05). However, immunization did not affect mRNA expressions for FSH-β, AR and ER-α in pituitary, or ER-α in testes. We concluded that anti-testosterone immunization in male rabbits, initiated during early puberty, increased GnRH mRNA expression and in turn LH synthesis by reducing testicular feedback signaling. Reduction of direct steroidal effects on the testis may also have increased testosterone secretion. Consequently, there was accelerated testicular development during puberty and enhanced testicular function after puberty, which likely conferred prolonged reproductive advantages.

      PubDate: 2014-04-14T17:48:51Z
  • Pivotal Roles for Hormonally Regulated Expression of the HEP21 Gene in the
           Reproductive Tract of Chickens for Oviduct Development and in Ovarian
    • Abstract: Publication date: Available online 5 April 2014
      Source:Domestic Animal Endocrinology
      Author(s): W. Lim , G. Song
      Hen egg protein (HEP21) is a 21 kDa secreted protein and has a single copy of the Ly6/uPAR domain. Although HEP21 is expressed primarily in the chicken oviduct, its biological function(s) in the reproductive system of chickens is not known. Thus, in the present study, we investigated expression patterns of HEP21 with respect to hormonal regulation, oviduct development, changes in expression in laying hens undergoing induced molting, and in the development of ovarian carcinogenesis in laying hens. Results of current study indicated that HEP21 mRNA expression increased (P < 0.001) in the chicken oviduct in response to estrogen. In situ hybridization analyses revealed expression of HEP21 mRNA predominantly in glandular (GE) and luminal epithelia of the magnum of the chicken oviduct in response to estrogen. The expression of HEP21 mRNA decreased (P < 0.001) as the oviduct regressed during induced molting and increased (P < 0.001) with recrudescence of the oviduct following molting. HEP21 mRNA was most abundant in GE of the oviduct during recrudescence, but not during oviduct regression following induced molting. Moreover, we found abundant expression of HEP21 in GE of cancerous ovaries, but not in normal ovaries of hens. Collectively, results of present study suggest that HEP21 is an estrogen-responsive gene in the oviduct of hens that likely regulates development of the chicken oviduct, and egg production and formation. Furthermore, there is increased expression of HEP21 in epithelial-derived ovarian cancer suggesting that HEP21 could be used for diagnosis and monitoring carcinogenesis in laying hens and in women.

      PubDate: 2014-04-10T13:41:05Z
  • A novel monoclonal antibody-based ELISA to determine luteinizing hormone
           in bovine plasma
    • Abstract: Publication date: Available online 5 April 2014
      Source:Domestic Animal Endocrinology
      Author(s): V. Borromeo , A. Berrini , F. De Grandi , F. Cremonesi , N. Fiandanese , P. Pocar , C. Secchi
      The development of a novel ELISA for determining luteinizing hormone (LH) in bovine plasma is described. Anti-bovine LH (bLH) monoclonal antibodies (mAbs) were produced and characterized. One mAb recognizing the bLH β subunit was used for immuno-affinity purification of substantial amounts of biologically active bLH from pituitary glands. The purified bLH in combination with two anti-bLH β subunit mAbs was used to develop a sandwich ELISA, which satisfied all the criteria required to investigate LH secretory patterns in the bovine species. The ELISA standard curve was linear over the range 0.05-2.5 ng/mL, and the assay proved suitable for measuring bLH in plasma without any prior treatment of samples. Cross-reactivity and recovery tests confirmed the specificity of the method. The intra- and inter-assay coefficients of variation ranged between 3.41% and 9.40%, and 9.29% and 15.84%, respectively. The analytical specificity of the method was validated in vivo by provocative tests for LH in heifers, using the LH releasing peptide GnRH. In conclusion, the adoption of mAbs for this ELISA for coating the wells and labeling, combined with the easy one-step production of reference bLH, ensures long-term continuity in large-scale measurements of LH in the bovine species.

      PubDate: 2014-04-10T13:41:05Z
  • Reducing exposure to long days from 75 to 30 days of extra-light treatment
           does not decrease the capacity of male goats to stimulate ovulatory
           activity in seasonally anovulatory females
    • Abstract: Publication date: Available online 20 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): José Luis Ponce , Hillary Velázquez , Gerardo Duarte , Marie Bedos , Horacio Hernández , Matthieu Keller , Philippe Chemineau , José Alberto Delgadillo
      The response of male goats exposed to different durations of long days (LD) during an extra-light treatment in autumn-winter, and their ability to induce ovulations in seasonally anovulatory goats were investigated in two experiments. In Experiment 1, control males were exposed to natural photoperiod (n = 5), whereas four additional groups (n = 5/group) were exposed to 16 h of light per d during 75, 45, 30, or 15 d of LD. In the four groups, photoperiodic treatments ended on January 15th. Plasma concentrations of testosterone were determined in blood samples obtained once a week from October 15th to May 30th. The rise of testosterone levels occurred earlier in males from the 75-LD and 45-LD groups than in those from the 30-LD, 15-LD and control groups (P < 0.05). In addition, the time during which levels of testosterone remained above 5 ng/mL was longer in males from the 75-LD and 45-LD than in those from the 30-LD and 15-LD groups (P < 0.05). In experiment 2, a group of anovulatory goats (n = 13) was isolated from males, while three additional groups were put in contact during 15 d with males previously exposed to 75, 45 or 30 days of LD (n = 25, 27, and 26 females/group, respectively and n = 3 males per group). The proportion of goats that ovulated was higher in the 3 groups in contact with the photo-stimulated males (range: 88-92 %) than in the group isolated from them (0 %; P < 0.05). The proportion of pregnant females did not differ between the three groups of does in contact with photo-stimulated males (range: 78-92%; P > 0.05). We conclude that, in our experimental conditions, a photoperiodic treatment as short as 30 d of LD during autumn-winter, stimulated testosterone secretion of bucks during their period of sexual rest and rendered them able to induce ovulations in seasonal anestrous goats and to obtain pregnancies in these females.

      PubDate: 2014-03-20T18:40:46Z
  • Isolation of endothelial cells and pericytes from swine corpus luteum
    • Abstract: Publication date: Available online 12 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): G. Basini , I. Falasconi , S. Bussolati , S. Grolli , R. Ramoni , F. Grasselli
      From an angiogenesis perspective, the ovary offers a unique opportunity to study the physiological development of blood vessels. The first purpose of this work was to set up a protocol for the isolation of pig corpus luteum endothelial cells, which were characterized by both morphological parameters and the expression of typical molecular markers; we also verified their ability to form capillary-like structures in a three-dimensional matrix, their response to hypoxia and their migration in the presence of Vascular Endothelial Growth Factor (VEGF). The effectiveness of our isolation protocol was confirmed by the characteristic “cobblestone shape” of isolated cells at confluence as well as their expression of all the examined endothelial markers. Our data also showed a significant cell production of VEGF and nitric oxide (NO). Isolated endothelial cells were also responsive to hypoxia by increasing the expression and production of VEGF and decreasing that of NO. In the angiogenesis bioassay, cells displayed the ability of forming capillary-like structures and also exhibited a significant migration in the scratch test. Our data suggest that the isolation of luteal endothelial cells represents a promising tool in experiments designed to clarify the biology of the angiogenic process. Furthermore, we have demonstrated that the isolated population comprises a subset of cells with a multidifferentiative capacity towards the chondrocytic and adipocytic phenotypes. These data suggest the presence of a perivascular or adventitial cell niche in the vascular wall of the corpus luteum populated with cells showing mesenchymal stem cell-like features, as already demonstrated the adipose tissue and endometrium.

      PubDate: 2014-03-16T12:06:12Z
  • Administration of estradiol benzoate prior to insemination could skew
           secondary sex ratio toward males in Holstein dairy cows
    • Abstract: Publication date: Available online 15 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): S.R. Emadi , A. Rezaei , M. Bolourchi , P. Hovareshti , V. Akbarinejad
      The present study was conducted to investigate the effect of estradiol benzoate administration prior to insemination on secondary sex ratio (proportion of male calves at birth) in Holstein dairy cows. Cows (n = 1647) were randomly assigned to two experimental groups by parity over a one-year period. Cows in the control group (n = 827; 232 primiparous and 595 multiparous cows) received two administrations of PGF2α (500 μg) 14 d apart started at 30 to 35 d postpartum. Twelve d after the second PGF2α injection, cows received GnRH (100 μg), followed by administration of PGF2α 7 d later. Cows in the treatment group (n = 820; 238 primiparous and 582 multiparous cows) received the same hormonal administrations as the cows in the control group. Additionally, cows in the treatment group received estradiol benzoate (1 mg) one day after the third PGF2α injection. Estrus detection by visual observation was started one day after the third PGF2α injection and after estradiol administration in the control (for 6 d) and treatment (for 36 h) groups, respectively. Artificial insemination was carried out 12 h after observation of standing estrus. Exposure of cows to heat stress at conception was determined based on temperature-humidity index. Estrus detection rate was lower in primiparous than in multiparous cows (P < 0.05), but conception rate was higher in primiparous versus multiparous cows (P < 0.05). Estradiol administration improved estrus detection rate and fertility (P < 0.05); moreover, it increased secondary sex ratio (adjusted odds ratio: 1.645; P = 0.017). Exposure to heat stress diminished heat detection rate and fertility (P < 0.05), and altered secondary sex ratio toward males (adjusted odds ratio: 2.863; P = 0.012). In conclusion, the present study revealed that estradiol administration before insemination could improve fertility and increase the probability of calves being male in Holstein dairy cows. Moreover, the results showed that cows exposed to heat stress around conception had diminished fertility and increased secondary sex ratio.

      PubDate: 2014-03-16T12:06:12Z
  • Contents
    • Abstract: Publication date: April 2014
      Source:Domestic Animal Endocrinology, Volume 47

      PubDate: 2014-03-10T16:45:32Z
  • Editorial Board
    • Abstract: Publication date: April 2014
      Source:Domestic Animal Endocrinology, Volume 47

      PubDate: 2014-03-10T16:45:32Z
  • Influence of feeding status, time of the day and season on baseline ACTH
           and the response to TRH-stimulation test in healthy horses
    • Abstract: Publication date: Available online 5 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): E. Diez de Castro , I. Lopez , B. Cortes , C. Pineda , B. Garfia , E. Aguilera-Tejero
      Equine pituitary pars intermedia function can be assessed by measurement of baseline and TRH-induced concentrations of ACTH; however, these measurements may be affected by the environment. Therefore, a prospective observational study evaluated the influence of a) feeding, b) time of the day, and c) season on baseline and TRH-induced concentrations of ACTH in healthy horses. Baseline ACTH was measured in 50 horses before and 2 h after feeding. Six research horses were subjected to a crossover study in which 6 TRH tests were performed in 2 different seasons, March-April (MA) and July-September (JS), at 2 different times of the day, 8:00 and 20:00 h, and, under 2 different conditions relative to feeding status, fasted and 2 h after feeding. Differences between fasted and fed horses were found in baseline ACTH, 17.1 ± 1.8 vs. 46.1 ± 7.6 pg/mL (P = 0.003) and TRH-stimulated ACTH: 124.1 ± 21.3 vs. 192.6 ± 33.1 pg/mL (P = 0.029) at 10 min, and 40.1 ± 4.9 vs. 73.2 ± 13.4 pg/mL (P = 0.018) at 30 min post TRH injection. No differences were found between tests performed at different times of the day. Basal ACTH concentrations were greater in JS than in MA, 17.1 ± 1.8 pg/mL vs. 11.9 ± 0.6 pg/mL (P = 0.006). A seasonal influence was also found in stimulated ACTH values, which were much greater in JS 122.7 ±3 6.7 pg/mL vs. 31.2 ± 7.4 pg/mL, at 10 min (P = 0.03) and 39.0 ± 7.2 pg/mL vs. 19.8 ± 3.1 pg/mL, at 30 min (P = 0.03). In addition to season, feeding is a potential confounding factor when measuring baseline or stimulated ACTH in horses. In conclusion, feeding status should be standardized for the diagnosis of equine PPID.

      PubDate: 2014-03-05T18:34:20Z
  • Influence of season and nutritional status on the direct effects of
           leptin, orexin-A and ghrelin on LH and GH secretion in the ovine pituitary
           explant model
    • Abstract: Publication date: Available online 5 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): K. Kirsz , M. Szczesna , K. Dudek , P.M. Bartlewski , D.A. Zieba
      The aim of this study was to examine whether leptin (anorexigenic peptide), orexin-A and ghrelin (orexigenic peptides) could directly (i.e., independently of hypothalamic influences) affect the secretion of luteinizing hormone (LH) and growth hormone (GH) by adenohypophyseal (AP) explants obtained from normally fed or fasted (48 h) ewes during the breeding and non-breeding seasons. In addition, a specific ovine leptin antagonist (SLAN-3) was used to assess the interactions between leptin and ghrelin/orexin-A. Pituitary glands from 16 ovariectomized Polish Longwool ewes that had received estradiol-releasing subcutaneous implants were collected in the breeding (November; n = 8) and non-breeding seasons (May; n = 8). The AP explants were incubated for 240 min in a gas-liquid interface and treated with leptin (50 ng/mL), ghrelin (100 ng/mL), orexin-A (100 ng/mL), and SLAN-3 (500 ng/mL) with orexin-A or ghrelin. Treatments with leptin and SLAN-3 + orexin-A increased (P < 0.05) LH concentrations in the cultures of AP explants from fasted animals in the breeding season. Orexin-A increased (P < 0.05) LH secretion by AP explants from both fasted and fed animals in the breeding season. Ghrelin stimulated (P < 0.05) GH secretion by AP explants collected from fasted animals in non-breeding season and from normally fed ewes in both seasons. Leptin decreased (P < 0.05) GH secretion by AP explants collected from fasted ewes in both seasons and from non-fasted ewes in the breeding season. However, the treatment with SLAN-3 + ghrelin resulted in greater (P < 0.05) GH concentrations compared with leptin treatment of AP explants from fasted ewes in the breeding season and from normally fed ewes in non-breeding season. In summary, leptin, orexin-A and ghrelin exerted direct effects on AP secretory function in an ex situ model, and both the reproductive season and nutritional status of the animals impinged on the direct effects of the peptides on LH and GH release. Specifically, orexin-A was more potent than leptin in directly stimulating LH secretion in cycling ewes, whereas ghrelin and leptin generally had opposing effects on the secretory function of somatotrophs in sheep.

      PubDate: 2014-03-05T18:34:20Z
  • Nursing supports neonatal porcine testicular development
    • Abstract: Publication date: Available online 5 March 2014
      Source:Domestic Animal Endocrinology
      Author(s): K.M. Rahman , J.E. Lovich , C. Lam , M.E. Camp , A.A. Wiley , F.F. Bartol , C.A. Bagnell
      The lactocrine hypothesis suggests a mechanism whereby milk-borne bioactive factors delivered to nursing offspring affect development of neonatal tissues. The objective of this study was to assess whether nursing affects testicular development in neonatal boars as reflected by: (1) Sertoli cell number and proliferation measured by GATA-4 expression and proliferating cell nuclear antigen (PCNA) immunostaining patterns; (2) Leydig cell development and steroidogenic activity as reflected by insulin-like factor 3 (INSL3) and P450 side chain cleavage (scc) enzyme expression; and (3) expression of estrogen receptor-alpha (ESR1), vascular endothelial growth factor (VEGF) A, and relaxin family peptide receptor (RXFP) 1. At birth, boars were randomly assigned (n = 6 - 7/group) to nurse ad libitum or to be pan fed porcine milk replacer for 48 h. Testes were collected from boars at birth, prior to nursing, and from nursed and replacer-fed boars at 50 h on postnatal day (PND) 2. Sertoli cell PCNA labeling index increased (P < 0.01) from birth to PND 2 in nursed, but not in replacer-fed boars. Sertoli cell number and testicular GATA-4 protein levels increased (P < 0.01) from PND 0 to PND 2 only in nursed boars. Neither age nor nursing affected testicular INSL3, P450scc, ESR1, or VEGFA levels. However, testicular RXFP1 levels increased (P < 0.01) with age and were greater in replacer-fed boars on PND 2. Results suggest that nursing supports neonatal porcine testicular development and provide additional evidence for the importance of lactocrine signaling in pigs.

      PubDate: 2014-03-05T18:34:20Z
  • Relationship of follicle size and concentrations of estradiol among cows
           exhibiting or not exhibiting estrus during a fixed-time AI protocol
    • Abstract: Publication date: Available online 15 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): G.A. Perry , O.L. Swanson , E.L. Larimore , B.L. Perry , G.D. Djira , R.A. Cushman
      Cows exhibiting estrus near the time of fixed-time AI had greater pregnancy success than cows showing no estrus. The objective of these studies were to determine the relationship between follicle size and peak estradiol concentration between cows that did or did not exhibit estrus during a fixed-time AI protocol. Ovulation was synchronized in beef cows by applying the CO-Synch protocol [GnRH (100 μg) on d -9, PGF2α (25 mg) on d -2, and a second injection of GnRH 48 h after PGF2α (d 0)] to both suckled (Exp.1) and non-suckled (Exp.2) cows. Follicle size (d 0) and ovulation (d 2) was determined by ultrasonography. Blood samples were collected every 3 or 4 h beginning at time of PGF2α injection (0 h). Estrus was detected by visual observation with the aid of estrus-detection patches, and cows that ovulated were classified as exhibited estrus (n = 46) or did not exhibit estrus (n = 63). In both suckled and non-suckled cows, there was a positive relationship between all cows (P < 0.05) and among those that exhibited estrus (P < 0.05), between follicle size and peak estradiol concentration, but no linear relationship (P > 0.50) between follicle size and peak estradiol concentration was observed among cows not exhibiting estrus. Cows that exhibited estrus had greater (P < 0.01) peak estradiol concentrations than cows that did not exhibit estrus. Suckled cows exhibiting standing estrus had greater (P < 0.001) preovulatory concentrations of estradiol beginning 6 h (replicate 1) or4 h (replicate 2) after the injection of PGF2α on day -2 compared with cows not exhibiting standing estrus. Non-suckled cows exhibiting standing estrus had greater (P < 0.001) preovulatory concentrations of estradiol beginning at the injection of PGF2α on day -2 compared with cows not exhibiting standing estrus. Furthermore, cows that exhibited estrus had an increased (P < 0.01) rate in the rise in concentrations of estradiol following the PGF2α to peak estradiol than cows not exhibiting estrus. In summary, follicle diameter had a positive relationship with peak concentrations of estradiol, but only among cows that exhibited standing estrus, and estradiol increased earlier in cows that exhibited estrus compared to cows that did not.

      PubDate: 2014-02-19T07:21:54Z
  • Myostatin alters glucose transporter-4 (GLUT4) expression in bovine
           skeletal muscles and myoblasts isolated from double muscled (DM) and
           normal muscled (NM) Japanese shorthorn cattle
    • Abstract: Publication date: Available online 10 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): H. Takahashi , K. Sato , T. Yamaguchi , M. Miyake , H. Watanabe , Y. Nagasawa , E. Kitagawa , S. Terada , M. Urakawa , M.T. Rose , C.D. McMahon , K. Watanabe , S. Ohwada , T. Gotoh , H. Aso
      The purpose of this study was to determine whether myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double muscled (DM) and normal muscled (NM) Japanese Shorthorn cattle. Plasma concentrations of glucose were lower in DM cattle than in NM cattle (P < 0.01). The expression of GLUT4 mRNA in the skeletal muscle ex vivo as well as in myoblasts at 72 h after differentiation in vitro was higher in DM cattle than in NM cattle (P < 0.01). In contrast, the NM and DM cattle did not differ with respect to skeletal muscle expression of GLUT1 and myocyte enhancer factor-2c (MEF2c), a transcription factor of GLUT4. In differentiated myoblasts, the expression of GLUT1, GLUT4 and MEF2c mRNAs was greater in DM cattle than in NM cattle (P < 0.01). In the presence and absence of insulin, glucose uptake in myoblasts was increased in DM cattle relative to that of NM cattle (P < 0.01). The addition of myostatin decreased the expression of GLUT4 and MEF2c mRNAs in DM myoblasts (P < 0.05). Results of the present study suggest that myostatin inhibits the expression of GLUT4 mRNA possibly via MEF2c, and that the greater ability of the DM cattle to produce muscle relative to the NM cattle may be due to their greater sensitivity to insulin and greater utilization of glucose.

      PubDate: 2014-02-14T20:33:01Z
  • Two or 24 h of daily contact with sexually active males results in
           different profiles of LH secretion that both lead to ovulation in
           anestrous goats
    • Abstract: Publication date: Available online 14 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): M. Bedos , G. Duarte , J.A. Flores , G. Fitz-Rodríguez , H. Hernández , J. Vielma , I.G. Fernández , P. Chemineau , M. Keller , J.A. Delgadillo
      Two experiments were conducted to a) determine whether sexually active males are able to stimulate the sexual activity of anestrous female goats when duration of contact is reduced to an intermittent contact shorter than 4 daily h and b) to compare the pattern of secretion of LH when anestrous goats are exposed either permanently or intermittently to males. In the first experiment, 4 groups of anovulatory goats were exposed to sexually active males for 24, 4, 2, or 1 h/d during 15 consecutive d, while control females remained isolated. More than 89% of females in the groups exposed to the sexually active bucks ovulated, whereas only 5% did so in the control group (P < 0.001). However, the proportion of females ovulating before day 4 was greater in the 2, 4 or 24-h contact groups than in the control, whereas it did not differ between the control group and the 1-h contact group (P = 0.02, < 0.001, < 0.001 and 0.23, respectively). In a second experiment, 3 groups of anovulatory goats were exposed permanently (24 h/d) or intermittently (2 h/d) to bucks during 5 d or remained isolated. We found that pulsatility of LH increased in the intermittent and permanent contact groups after males were introduced to females (P = 0.05); this pulsatility of LH remained elevated in the permanent-contact group, whereas it decreased in the intermittent-contact group, once the male was removed (P = 0.32 and 0.05, respectively). We conclude that 1 or 2 daily h of contact with sexually active males is sufficient to stimulate ovulatory activity in anovulatory goats; however, ovulation is obtained through a different pattern of secretion of LH.

      PubDate: 2014-02-14T20:33:01Z
  • Gonadectomy-related adrenocortical tumors in ferrets demonstrate increased
           expression of androgen and estrogen synthesizing enzymes together with
           high inhibin expression
    • Abstract: Publication date: Available online 14 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): M.K. de Jong , E.E.M. ten Asbroek , A.J. Sleiderink , A.J. Conley , J.A. Mol , N.J. Schoemaker
      The two objectives of this study were to 1) measure by qPCR the expression of genes involved in steroid and inhibin synthesis in adrenocortical tumors of gonadectomized ferrets and 2) localize by immunohistochemistry several proteins that are key to adrenal steroidogenesis. Relative to the control adrenals, expression of the mRNAs encoding StAR, CYP11A (P = 0.019), CYP21 (P = 0.01) and 3ß-HSD (P = 0.004), all involved in the synthesis of mineralocorticoids and glucocorticoids, was decreased in the adrenocortical tumors. In contrast, expression of cytochrome B5 (CytB5; P = 0.0001) and aromatase (P = 0.003), involved in androgen and estrogen synthesis, and both inhibin α-subunit (P = 0.002) and ßB-subunit (P = 0.001) were upregulated. In tumors immunostaining of CYP21 was low whereas staining of Cyp17 and CytB5, necessary for androgen synthesis, was present. It is concluded that ferret adrenocortical tumors express genes for androgen production. In addition, the expression of aromatase as well as inhibin suggests an even more gonadal differentiation which is reminiscent to the fact that both gonads and adrenals are derived from a common urogenital primordial cell.

      PubDate: 2014-02-14T20:33:01Z
  • Energy and metabolic sensing G protein-coupled receptors during
           lactation-induced changes in energy balance
    • Abstract: Publication date: Available online 7 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): P. Friedrichs , B. Saremi , S. Winand , J. Rehage , S. Dänicke , H. Sauerwein , M. Mielenz
      The free fatty acid receptor (FFA) 1, FFA2, FFA3 and hydroxy-carboxylic acid receptor (HCA)2 are G protein-coupled receptors, acting as energy and metabolic sensors. Herein, we characterized the tissue-specific mRNA abundance of genes encoding for these receptors at different stages of lactation. In addition, potential effects of supplementation with or without conjugated linoleic acids (CLA) were tested. Tissues from pluriparous cows (subcutaneous adipose tissue (SAT) and liver) and from primiparous cows (3 SAT locations, 3 visceral adipose tissues (VAT), liver, mammary gland and skeletal muscle) were used from 2 separate trials. In primiparous cows the mRNA abundance of all receptors (FFA3 was not detectable by the applied protocol in muscle and udder) was lowest in muscle (P < 0.05). With exception of FFA1, gene expression of the investigated receptors was higher in AT than in the non-AT. Expression of FFA1 in liver (P < 0.03), of FFAR2 in SAT (P < 0.01) and HCA2 in SAT (P < 0.01) from pluriparous cows changed during the observation period (days -21 to d 252 relative to parturition). The correlation between mRNA abundance of HCA2 and peroxisome proliferator-activated receptor γ (PPARG) and likewise PPARG2 (P < 0.01) in SAT indicates a link between HCA2 and PPARG. Differences in receptor mRNA abundance between the CLA-fed and the control animals were scarce and limited to HCA2 and FFA1 in 1 and 2 time points, respectively (less hepatic HCA2 mRNA in CLA-fed pluriparous cows, and greater FFA1 mRNA abundance in 2 VAT depots in CLA-treated primiparous cows). In view of the metabolic changes occurring during the different phases of lactation, in particular the altered concentrations of non-esterified fatty acids (NEFA) and β -hydroxybutyrate (BHB) acting as receptor ligands, the longitudinal, tissue-specific characterization provided herein allows for a first insight into the regulation of these receptors at the gene expression level.

      PubDate: 2014-02-10T07:28:27Z
  • Impact of maternal physical activity during gestation on porcine fetal,
           neonatal, and adolescent ovarian development
    • Abstract: Publication date: Available online 7 February 2014
      Source:Domestic Animal Endocrinology
      Author(s): S.L. Kaminski , A.T. Grazul-Bilska , E.K. Harris , E.P. Berg , K.A. Vonnahme
      To determine how exercise from mid to late (days 40 to 104) gestation impacts offspring body, uterine and ovarian weight, and ovarian cell proliferation at three different developmental stages, Yorkshire gilts were either exercised by walking (EX) or not exercised (CON). In parity one ovaries and uteri were collected from the heaviest (H) and lightest (L) neonates, and adolescent (6 mo) offspring. In parity two, mothers were assigned the same treatment groups, and ovaries and uteri were collected from H and L fetuses on day 94 of gestation. Body weight was greater (P < 0.02) for H than L fetuses and neonates but not affected by EX-treatment at any developmental stage. Ovarian weight in L but not H neonates was greater (P < 0.02) in EX than CON. Labeling index (LI; percentage of proliferating cells) was greater (P < 0.01) in cortex than medulla regions of fetal and neonatal ovaries. In fetal ovaries, EX enhanced LI (P < 0.01), and LI was greater (P < 0.01) in H compared to L offspring. In adolescent ovaries, LI was greatest (P < 0.01) in healthy antral and least in atretic antral follicles, and LI was greater (P < 0.01) in granulosa than theca cells of healthy antral follicles. Thus, exercise increased LI in fetal but not neonatal or adolescent ovaries. While maternal exercise during gestation influences fetal and neonatal ovarian development, impacts on fertility remain unknown.

      PubDate: 2014-02-10T07:28:27Z
  • Expression and localization of ghrelin and its functional receptor in
           corpus luteum during different stages of estrous cycle and the modulatory
           role of ghrelin on progesterone production in cultured luteal cells in
    • Abstract: Publication date: Available online 21 January 2014
      Source:Domestic Animal Endocrinology
      Author(s): M. Gupta , S.S. Dangi , V.S. Chouhan , I. Hyder , V. Babitha , V.P. Yadav , F.A. Khan , A. Sonwane , G. Singh , G.K. Das , A. Mitra , S. Bag , M. Sarkar
      Evidence obtained during recent years provided insight into the regulation of corpus luteum (CL) development, function and regression by locally produced ghrelin. The present study was carried out to evaluate expression and localization of ghrelin and its receptor (GHS-R1a) in bubaline CL during different stages of the estrous cycle and to investigate the role of ghrelin on progesterone (P4) production along with mRNA expression of P4 synthesis intermediates. The mRNA and protein expression of ghrelin and GHS-R1a was significantly greater in mid and late luteal phases. Both factors were localized in luteal cells, exclusively in the cytoplasm. Immunoreactivity of ghrelin and GHS-R1a was greater during mid and late luteal phases. Luteal cells were cultured in vitro and treated with ghrelin each at 1, 10 and 100 ng/mL concentrations for 48 h after obtaining 75-80% confluence. At a dose of 1 ng/mL, there was no significant difference in progesterone secretion between control and treatment group. At 10 and 100 ng/mL there was a decrease (P< 0.05) in progesterone concentration, cytochrome P45011A1 (CYP11A1) and 3beta-hydroxysteroid dehydrogenase (3β-HSD) mRNA expression and localization. There was no difference in mRNA expression of steroidogenic acute regulatory protein (StAR) between control and treatment group. In summary, the present study provided evidence that ghrelin and its receptor are expressed in bubaline CL and are localized exclusively in the cell cytoplasm and ghrelin has an inhibitory effect on P4 production in buffalo.

      PubDate: 2014-01-22T07:42:07Z
  • The epidermal growth factor receptor is required for estradiol-stimulated
           bovine satellite cell proliferation
    • Abstract: Publication date: Available online 19 January 2014
      Source:Domestic Animal Endocrinology
      Author(s): B.C. Reiter , E. Kamanga-Sollo , M.S. Pampusch , M.E. White , W.R. Dayton
      The objective of this study was to assess the role of the epidermal growth factor receptor (EGFR) in estradiol-17β (E2)-stimulated proliferation of cultured bovine satellite cells (BSC). Treatment of BSC cultures with AG1478 (a specific inhibitor of EGFR tyrosine kinase activity) suppresses E2-stimulated BSC proliferation ( P < 0.05). Additionally, E2-stimulated proliferation is completely suppressed (P < 0.05) in BSC in which EGFR expression is silenced by treatment with EGFR small interfering RNA (siRNA). These results indicate that EGFR is required in order for E2 to stimulate proliferation in BSC cultures. Both AG1478 treatment and EGFR silencing also suppress LR3-IGF-1- (an IGF1 analogue that binds normally to the IGFR-1 but has little or no affinity for IGF binding proteins) stimulated proliferation in cultured BSC (P < 0.05). Even though EGFR siRNA treatment has no effect on IGFR-1β mRNA expression in cultured BSC, IGFR-1β protein level is substantially reduced in BSC treated with EGFR siRNA. These data suggest that EGFR silencing results in post transcriptional modifications that result in decreased IGFR-1β protein levels. Although it is clear that functional EGFR is necessary for E2 stimulated proliferation of BSC, the role of EGFR is not clear. Transactivation of EGFR may directly stimulate proliferation or EGFR may function to maintain the level of IGFR-1β which is necessary for E2 stimulated proliferation. It also is possible that the role of EGFR in E2-stimulated BSC proliferation may involve both of these mechanisms.

      PubDate: 2014-01-22T07:42:07Z
  • Effect of RU486 and indomethacin on meiotic maturation, formation of
           extracellular matrix and progesterone production by porcine oocyte-cumulus
    • Abstract: Publication date: Available online 21 January 2014
      Source:Domestic Animal Endocrinology
      Author(s): E. Nagyova , S. Scsukova , J. Kalous , A. Mlynarcikova
      This study was designed to determine whether inhibition of either cyclooxygenase-2 (COX-2) by indomethacin or progesterone receptor (PR) by PR antagonist, RU486, affects oocyte maturation, progesterone production and covalent binding between hyaluronan (HA) and heavy chains of inter-alpha trypsin inhibitor (IαI) as well as expression of cumulus expansion-associated proteins (HABP, TNFAIP6, PTX3) in oocyte-cumulus complexes (OCC). The experiments were based on freshly isolated porcine OCC cultures in which the consequences of PR and COX-2 inhibition on the final processes of oocyte maturation were determined. Granulosa cells (GCs) and OCC were cultured in medium supplemented with FSH/LH (both 100 ng/mL) in the presence/absence of RU486 or indomethacin. Western blot analysis, 3H-glucosamine hydrochloride assay, immunofluorescence and radioimmunoassay were performed. Only treatment with RU486 (25 μM) caused a decrease in the number of oocytes reaching germinal vesicle breakdown (GVBD) and metaphase II (M II) stage compared with indomethacin (100 μM) or FSH/LH treatment alone after 44 h. All treated OCC synthesized an almost equal amount of HA. Heavy chains (of IαI)-HA covalent complexes were formed during in vitro FSH/LH-stimulated expansion in RU486- or indomethacin-treated OCC. FSH/LH-induced progesterone production by OCC was increased in the presence of RU486 after 44 h. In contrast, a decrease of FSH/LH-stimulated progesterone production by GCs was detected in the presence of either RU486 or indomethacin after 72 h. We suggest that the PR-dependent pathway may be involved in the regulation of oocyte maturation. Both PR and COX-2 regulate FSH/LH-stimulated progesterone production by OCC and GCs.

      PubDate: 2014-01-22T07:42:07Z
  • Characterization of glucagon-like peptide 2 receptor (GLP2R) gene in
           chickens: functional analysis, tissue distribution, and developmental
           expression profile of GLP2R in embryonic intestine
    • Abstract: Publication date: Available online 18 January 2014
      Source:Domestic Animal Endocrinology
      Author(s): C. Mo , Y. Zhong , Y. Wang , Z. Yan , J. Li
      This study characterized the glucagon-like peptide 2 receptor (GLP2R) gene of chickens because relatively little is known about the underlying mechanism of GLP2 actions in non-mammalian species. Using RT-PCR, we first cloned the chicken GLP2R (cGLP2R) from adult intestine, which was predicted to encode a 529-amino acid receptor precursor. Using a pGL3-CRE luciferase reporter system, we demonstrated that cGLP2R expressed in CHO cells could be potently activated by cGLP2 (EC50, 1.06 nM), but not by its structurally related peptides (EC50, >19 nM), including the newly identified glucagon-like peptide (cGCGL), indicating that cGLP2R is a functional receptor specific to cGLP2. RT-PCR assay revealed that cGLP2R mRNA was widely expressed in adult chicken tissues, including pancreas and various parts of gastrointestinal tract. Using quantitative real-time RT-PCR assays, we further investigated the mRNA expression of cGLP2R and its potential downstream mediators, EGFR ligands (HB-EGF, EREG, and AREG), in the distal duodenum of developing embryos. The mRNA expression levels of GLP2R and EGFR ligands (HB-EGF and AREG) were shown to increase (P, < 0.05 or 0.01) during the late embryonic stages (E16 and E20), implying a potential coordinated action of GLP2 and EGFR ligands on embryonic intestine development. Taken together, our findings not only establish a molecular basis to explore the physiological roles of GLP2 in birds, but also provide comparative insights into the roles of GLP2R and its ligand in vertebrates, such as its roles in embryonic intestine development.

      PubDate: 2014-01-19T04:16:03Z
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