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  Subjects -> VETERINARY SCIENCE (Total: 213 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 11)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
African Journal of Wildlife Research     Full-text available via subscription  
Alexandria Journal of Veterinary Sciences     Open Access   (Followers: 1)
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 11)
American Journal of Primatology     Hybrid Journal   (Followers: 7)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 24)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 4)
Animal Behaviour     Hybrid Journal   (Followers: 131)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 5)
Animal Nutrition     Open Access   (Followers: 7)
Animal Reproduction     Open Access  
Animal Reproduction Science     Hybrid Journal   (Followers: 6)
Animals     Open Access   (Followers: 6)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access  
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: 2)
Australian Veterinary Journal     Hybrid Journal   (Followers: 15)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 5)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 3)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 1)
Bangladesh Veterinarian     Open Access   (Followers: 1)
BMC Veterinary Research     Open Access   (Followers: 10)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 6)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 5)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 2)
Equine Health     Full-text available via subscription   (Followers: 1)
Equine Veterinary Education     Hybrid Journal   (Followers: 8)
Equine Veterinary Journal     Hybrid Journal   (Followers: 12)
Ethiopian Veterinary Journal     Open Access   (Followers: 4)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 2)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
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)
Indonesia Medicus Veterinus     Open Access  
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 5)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 7)
InVet     Open Access  
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 5)
İstanbul Üniversitesi Veteriner Fakültesi Dergisi     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 6)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 11)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 2)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 6)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 10)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 4)
Journal of Experimental and Applied Animal Sciences     Open Access  
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 11)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 29)
Journal of the Selva Andina Research Society     Open Access  
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 9)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 16)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 18)
Journal of Veterinary Medical Education     Partially Free   (Followers: 14)

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Journal Cover Domestic Animal Endocrinology
  [SJR: 0.882]   [H-I: 53]   [2 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0739-7240
   Published by Elsevier Homepage  [2801 journals]
  • Expression analysis of bone morphogenetic protein 4 between fat and lean
           birds in adipose tissue and serum
    • Abstract: Publication date: Available online 30 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): B.H. Cheng, L. Leng, M.Q. Wu, Q. Zhang, X.Y. Zhang, S.S. Xu, Z.P. Cao, Y.M. Li, P. Luan, H. Li
      The objectives of the current study were to characterize the tissue expression of chicken (Gallus gallus) bone morphogenetic protein 4 (BMP4) and compare differences in its expression in abdominal fat tissue and serum between fat and lean birds, and to determine a potential relationship between the expression of BMP4 and abdominal fat tissue growth and development. The results showed that chicken BMP4 mRNA and protein were expressed in various tissues, and the expression level of BMP4 transcript and protein was relatively higher in adipose tissues. In addition, the mRNA and protein expression levels of BMP4 in abdominal fat tissue of fat males were lower than that of lean males at 1, 2, 5 and 7 wk of age (P < 0.05). Furthermore, the serum BMP4 content of fat males was lower than that of lean males at 7 wk of age (P < 0.05). Bone morphogenetic protein 4 mRNA expression levels were significantly higher in preadipocytes than in mature adipocytes (P < 0.05), and the expression level decreased during differentiation in vitro (P < 0.05). These results suggested that chicken BMP4 might affect abdominal fat deposition through differences in its expression level. The results of this study will provide basic molecular information for studying the role of BMP4 in the regulation of adipogenesis in avian species.

      PubDate: 2016-02-01T12:11:52Z
  • Effects of steroid treatment on growth, nutrient partitioning, and
           expression of genes related to growth and nutrient metabolism in adult
           triploid rainbow trout (Oncorhynchus mykiss)
    • Abstract: Publication date: Available online 25 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): B.M. Cleveland, G.M. Weber
      The contribution of sex steroids to nutrient partitioning and energy balance during gonad development was studied in rainbow trout. Specifically, 19-mo old triploid (3N) female rainbow trout were fed treatment diets supplemented with estradiol-17β (E2), testosterone (T), or dihydrotestosterone (DHT) at 30 mg steroid/kg diet for a 1-mo period. Growth performance, nutrient partitioning, and expression of genes central to growth and nutrient metabolism were compared to 3N and age-matched diploid (2N) female fish consuming a control diet not supplemented with steroids. Only 2N fish exhibited active gonad development, with gonad weights (GSI) increasing from 3.7% to 5.5% of body weight throughout the study while GSI in 3N fish remained at 0.03%. Triploid fish consuming DHT exhibited faster specific growth rates than 3N controls (P < 0.05). Consumption of E2 in 3N fish reduced fillet growth and caused lower fillet yield compared to all other treatment groups (P < 0.05). In contrast, viscera fat gain was not affected by steroid consumption (P > 0.05). Gene transcripts associated with physiological pathways were identified in maturing 2N and E2-treated 3N fish that differed in abundance from 3N control fish (P < 0.05). In liver these mechanisms included the growth hormone/insulin-like growth factor (IGF) axis (igf1, igf2), IGF binding proteins (igfbp1b1, igfbp2b1, igfbp5b1, igfbp6b1), and genes associated with lipid binding and transport (fabp3, fabp4, lpl, cd36), fatty acid oxidation (cpt1a), and the pparg transcription factor. In muscle these mechanisms included reductions in myogenic gene expression (fst, myog) and the proteolysis-related gene, ctsl, suggesting an E2-induced reduction in the capacity for muscle growth. These findings suggest that increased E2 signaling in the sexually maturing female rainbow trout alters physiological pathways in liver, particularly those related to IGF signaling and lipid metabolism, to partition nutrients away from muscle growth towards support of maturation-related processes. In contrast, the mobilization of viscera lipid stores appear to be mediated less by E2 and more by energy demands associated with gonad development. These findings improve understanding of how steroids regulate nutrient metabolism to meet the high energy demands associated with gonad development during sexual maturation.

      PubDate: 2016-01-28T12:02:36Z
  • Leptin concentrations in finishing beef steers and heifers and their
           association with dry matter intake, average daily gain, feed efficiency,
           and body composition
    • Abstract: Publication date: Available online 6 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): A.P. Foote, R.G. Tait, D.H. Keisler, K.E. Hales, H.C. Freetly
      The objective of this experiment was to determine the association of circulating plasma leptin concentrations with production and body composition measures of finishing beef steers and heifers and to determine if multiple sampling time points improve the associations of plasma leptin concentrations with production and body composition traits. Individual DMI and ADG were determined for 84 d using steers and heifers (n = 127 steers and n = 109 heifers). Blood was collected on day 0, day 42, and day 83 for determination of plasma leptin concentrations. Leptin concentrations was greater in heifers than steers on day 0 (P < 0.001 for sex by day interaction) and leptin concentrations increased in both sexes but was not different from each other on day 83. Leptin concentrations at all three time points and the mean were shown to be positively associated with DMI (P ≤ 0.006) while the mean leptin concentration explaining 8.3 % of the variance of DMI. Concentrations of leptin at day 42, day 83, and the mean of all three time points were positively associated with ADG (P ≤ 0.011). Mean leptin concentration was negatively associated with G:F and positively associated with residual feed intake (RFI), indicating that more efficient cattle had lower leptin concentrations. However, leptin concentrations explained very little of the variation in RFI (≤ 3.2 % of the variance). Leptin concentrations were positively associated with body fat measured by ultrasonography at the 12th-rib and over the rump (P < 0.001), with the mean leptin concentration explaining 21.9 % and 12.7 % of the variance in 12th rib and rump fat thickness, respectively. The same trend was observed with carcass composition where leptin concentrations were positively associated with 12th rib fat thickness, USDA calculated yield grade (YG), and marbling score (P ≤ 0.006) and mean leptin concentration explained 16.8, 18.2, and 4.6 % of the variance for 12th rib fat thickness, YG, and marbling score, respectively. Given these and previous results, it appears that leptin physiology could be a candidate for mechanisms that contribute to feed intake and feed efficiency variation in beef cattle.

      PubDate: 2016-01-09T09:23:37Z
  • Ovarian follicle development in vitro and oocyte competence: advances and
           challenges for farm animals
    • Abstract: Publication date: Available online 7 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): J.R.V. Silva, R. van den Hurk, J.R. Figueiredo
      During the last two decades, research on in vitro preantral follicle growth and oocyte maturation has delivered fascinating advances concerning the knowledge of processes regulating follicle growth and the developmental competence of oocytes. These advances include: (1) information about the role of several hormones and growth factors on in vitro activation of primordial follicles; (2) increased understanding of the intracellular pathway involved in the initiation of primordial follicle growth, (3) the growth of primary and secondary follicles up to antral stages, and (4) production of embryos from oocytes from in vitro grown preantral follicles. This review paper describes these advances, especially in regard farm animals, and discusses the reasons that limit embryo production from oocytes derived from preantral follicles cultured in vitro.

      PubDate: 2016-01-09T09:23:37Z
  • Plasma concentrations of acyl-ghrelin are associated with average daily
           gain and feeding behavior in grow-finish pigs1
    • Abstract: Publication date: Available online 4 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): C.A. Lents, T.M. Brown-Brandl, G.A. Rohrer, W.T. Oliver, B.A. Freking
      The objectives of this study were to determine the effect of sex, sire line, and litter size on concentrations of acyl-ghrelin and total ghrelin in plasma of grow-finish pigs, and to understand the relationship of plasma concentrations of ghrelin with feeding behavior, average daily gain (ADG), and back fat (BF) in grow-finish swine. Yorkshire-Landrace crossbred dams were inseminated with semen from Yorkshire, Landrace, or Duroc sires. Within 24 h of birth, pigs were cross-fostered into litter sizes of normal (N; > 12 pigs/litter) or small (S; ≤ 9 pigs/litter). At 8 wk of age, pigs (n = 240) were blocked by sire breed, sex, and litter size and assigned to pens (n = 6) containing commercial feeders modified with a system to monitor feeding behavior. Total time eating, number of daily meals, and duration of meals were recorded for each individual pig. Body weight (BW) was recorded every 4 wk. Back fat and loin eye area (LEA) were recorded at the conclusion of the 12-wk feeding study. A blood sample was collected at week 7 of the study to quantify concentrations of acyl- and total ghrelin in plasma. Pigs from S litters weighed more (P < 0.05) and tended (P = 0.07) to be fatter than pigs from N litters. Postnatal litter size did not affect ADG, feeding behavior, or concentrations of ghrelin in plasma during the grow-finish phase. Barrows spent more time eating (P < 0.001) than gilts but the number of meals and concentrations of ghrelin did not differ with sex of the pig. Pigs from Duroc and Yorkshire sires had lesser (P < 0.0001) concentrations of acyl-ghrelin than pigs from Landrace sires, but plasma concentrations of total ghrelin were not affected by sire breed. Concentrations of acyl-ghrelin were positively correlated with the number of meals and negatively correlated with meal length and ADG (P < 0.05). A larger number of short-duration meals may indicate that pigs with greater concentrations of acyl-ghrelin consumed less total feed, which likely explains why they were leaner and grew more slowly. Acyl-ghrelin is involved in regulating feeding behavior in pigs, and measuring acyl-ghrelin is important when trying to understand the role of this hormone in swine physiology.

      PubDate: 2016-01-05T08:15:32Z
  • Concentrations of progesterone, a metabolite of PGF2α, prolactin, and
           LH during development of idiopathic persistent corpus luteum in mares
    • Abstract: Publication date: Available online 28 December 2015
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, J.M. Baldrighi, T. Castro, C.A. Wolf, V.G. Santos
      In experiment 1, daily blood samples were available from Days 0 to 20 (Day 0 = ovulation) in mares with an interovulatory interval (IOI, n=5) and in mares that developed idiopathic persistent corpus luteum (PCL, n=5). The PCL was confirmed by maintenance of progesterone (P4) concentration until end of the experiment (Day 20). Significant interactions of group and day revealed the novel findings that LH was lower (P < 0.05) in the PCL group than in the IOI group on Days 0 to 4, and prolactin was lower (P < 0.05) on Days 1, 4, 6, and 7. In experiment 2, treatment with a GnRH antagonist (n=6) significantly reduced LH on Days 1 to 6 compared to the controls (n=6) but did not support the hypothesis that low LH during the postovulatory period increases the frequency of PCL. In experiment 3, P4, PGFM (a PGF2α metabolite), and prolactin concentrations on Days 12 to 20 from 2 reported experiments were combined to increase the number of mares with an IOI (n=11) or a PCL (n=11). An abrupt and complete decrease in P4 (luteolysis) began on Day 13 in the IOI group compared to a gradual and partial P4 decline after Day 12 in the PCL group. Concentrations of PGFM and prolactin were lower (P < 0.05) in the PCL group than in the IOI group on the day at the end of the most pronounced decrease in P4. The PCL mares were subgrouped into those with an abrupt but incomplete P4 decrease (partial luteolysis; n=5) at the expected time and those without partial luteolysis (n=6). There were no significant differences between the 2 subgroups in concentrations of PGFM and prolactin, but on a tentative basis (P < 0.10) concentration of PGFM seemed more focused on the day of the most pronounced decrease in P4 in the subgroup with partial luteolysis. Results for PCL compared to IOI indicated: (1) postovulatory LH and prolactin were lower, (2) treatment to reduce postovulatory LH did not increase the incidence, and (3) both PGFM and prolactin were lower on the day of the most pronounced decrease in P4.

      PubDate: 2016-01-01T04:42:24Z
  • Aquaporin 3 is regulated by estrogen in the chicken oviduct and it is
           involved in progression of epithelial cell-derived ovarian carcinomas
    • Abstract: Publication date: Available online 23 December 2015
      Source:Domestic Animal Endocrinology
      Author(s): C. Yang, W. Lim, H. Bae, G. Song
      Aquaporins (AQPs) are membrane proteins that passively deliver water across the plasma membrane to play an important role in maintaining cell shape. Members of the AQP family are distributed in the majority of tissues in the human body and perform a variety of functions based on the water homeostasis suitable for each organ. However, there is little known about expression and regulation of AQP family members in chickens. Therefore, we determined the expression of AQPs in various tissues of chickens. Among 13 isotypes, AQP3 was highly expressed in the chicken oviduct. Expression of AQP3 mRNA increased in the magnum (P < 0.001) and isthmus (P < 0.001) of chick oviducts treated with diethylstilbestrol (DES). Consistent with these results the localization of AQP3 was detected in the glandular (GE) and luminal (LE) epithelia of the magnum and isthmus of oviducts of DES-treated chicks. In addition, the pattern of expression of AQP3 changed in an estrogen-dependent manner during the molting period. During the regenerative period of the oviduct after molting, expression of AQP3 mRNA increased coordinately with increaseing concentrations of estradiol (P < 0.001), whereas expression of AQP3 mRNA decreased as concentrations of estradiol in plasma decreased in response to induced molting (P < 0.001). Also, expression of the AQP3 increased (P<0.001) in cancerous ovaries of laying hens. In conclusion, AQP3 does not simply function to transport water into and out of cells, but also appears to be closely involved in development of the chicken oviduct which is regulated by estrogens. Furthermore, our results suggest AQP3 as a new diagnostic for early detection and treatment of epithelial cell-derived ovarian carcinomas.

      PubDate: 2015-12-24T02:57:40Z
  • Expression and immunolocalization of membrane progesterone receptors in
           the bovine oviduct
    • Abstract: Publication date: Available online 17 December 2015
      Source:Domestic Animal Endocrinology
      Author(s): M.K. Kowalik, M. Martyniak, R. Rekawiecki, J. Kotwica
      The oviduct plays a crucial role in the transport and maturation of gametes and ensures suitable conditions for fertility and early embryo development. One regulator of oviduct function is progesterone (P4), which affects the cell by interacting with nuclear progesterone receptors (PGR) as well as through non-genomic mechanisms, presumably involving membrane progesterone receptors. The aim of this study was to evaluate expression of mRNAs and proteins for progesterone receptor membrane component (PGRMC) 1 and 2 and membrane progestin receptors (mPR) α, β and γ and to use immunohistochemistry to demonstrate their cell-specific localization in the bovine oviduct. Oviducts ipsilateral and contralateral to the CL or to the dominant follicle were collected from cows on days 6-12 (mid-luteal stage) and 18-20 (follicular stage) of the estrous cycle and divided into three parts (infundibulum, ampulla and isthmus). There were no differences (P>0.05) in the PGRMC1, PGRMC2, mPRα, β and γ mRNA expression between ipsi- and contralateral oviducts. However, the same parts of the oviduct collected during the different stages of the estrous cycle showed higher (P<0.05) mRNA levels of PGRMC1, PGRMC2 and mPRα on days 18-20 than on days 6-12 of the estrous cycle. mPRα and mPRβ mRNA levels were higher (P<0.05) in the infundibulum than in the isthmus, while PGRMC1 expression was higher (P<0.05) in the infundibulum than in ampulla. Immunohistochemistry was used to detect PGRMC1, PGRMC2, PRα, β and γ proteins in all parts of both oviducts from days 6-12 and 18-20 of the estrous cycle. There were no differences in the staining intensity and cellular localization of the studied proteins between the ipsi- and contralateral oviducts and between the studied stages of the estrous cycle. A strong positive reaction was observed in luminal cells, but this reaction was less evident in myocytes and stromal cells. All proteins were also localized to the endothelial cells of blood vessels. These results suggest that membrane P4 receptors, may be involved in the regulation of oviduct motility, secretory function and blood flow in this organ.

      PubDate: 2015-12-20T02:50:22Z
  • Endogenous and exogenous factors influencing the concentrations of
           adiponectin in body fluids and tissues in the bovine
    • Abstract: Publication date: Available online 13 December 2015
      Source:Domestic Animal Endocrinology
      Author(s): Helga Sauerwein, Susanne Häußler
      Adiponectin, one of the messenger molecules secreted from adipose tissue that are collectively termed adipokines, has been demonstrated to play a central role in lipid and glucose metabolism in humans and laboratory rodents; it improves insulin sensitivity and exerts anti-diabetic and anti-inflammatory actions. Adiponectin is synthesized as a 28 kDa monomer but is not secreted as such; instead it is glycosylated and undergoes multimerization to form different molecular weight (MW) multimers prior to secretion. Adiponectin is one of the most abundant adipokines (μg/mL range) in the circulation. The concentrations are negatively correlated with adipose depot size, in particular with visceral fat mass in humans. Adiponectin exerts its effects by activating a range of different signaling molecules via binding to two transmembrane receptors, AdipoR1 and AdipoR2. The AdipoR1 is expressed primarily in the skeletal muscle, whereas AdipoR2 is predominantly expressed in the liver. Many of the functions of adiponectin are relevant to growth, lactation and health and are thus of interest in both beef and dairy production systems. Studies on the role of the adiponectin protein in cattle have been impeded by the lack of reliable assays for bovine adiponectin. While there are species specific bovine adiponectin assays commercially available, they suffer from a lack of scientific peer-review of validity. Quantitative data about the adiponectin protein in cattle available in the literature emerged only during the last three years and were largely based on Western blotting using either antibodies against human adiponectin or partial peptides from the bovine sequence. Using native bovine high MW adiponectin purified from serum, we were able to generate a polyclonal antiserum that can be used for Western Blot but also in an ELISA system which was recently validated. The objective of this review is to provide an overview of the literature about the adiponectin protein in cattle addressing the following aspects: (a) the course of the adiponectin serum concentrations during development in both sexes, during inflammation, nutritional energy deficit and energy surplus, and lactation-induced changes including the response to supplementation with conjugated linoleic acids and with niacin, (b) the concentrations of adiponectin in subcutaneous versus visceral fat depots of dairy cows, (c) the protein expression of adiponectin in tissues other than adipose and (d) the concentrations in different body fluids including milk.

      PubDate: 2015-12-16T02:41:26Z
  • Editorial Board
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54

      PubDate: 2015-12-12T02:30:57Z
  • Table of Contents
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54

      PubDate: 2015-12-12T02:30:57Z
  • Changes in brain ribonuclease (BRB) messenger RNA in granulosa cells (GCs)
           of dominant vs subordinate ovarian follicles of cattle and the regulation
           of BRB gene expression in bovine GCs
    • Abstract: Publication date: Available online 31 October 2015
      Source:Domestic Animal Endocrinology
      Author(s): J.L. Dentis, N.B. Schreiber, J.N. Gilliam, L.F. Schutz, L.J. Spicer
      Brain ribonuclease (BRB) is a member of the ribonuclease A superfamily that is constitutively expressed in a range of tissues and is the functional homolog of human ribonuclease 1. This study was designed to characterize BRB gene expression in granulosa cells (GCs) during development of bovine dominant ovarian follicles and to determine the hormonal regulation of BRB in GCs. Estrous cycles of Holstein cows (n = 18) were synchronized, and cows were ovariectomized on either day 3 to 4 or day 5 to 6 after ovulation during dominant follicle growth and selection. Ovaries were collected, follicular fluid (FFL) was aspirated, and GCs were collected for RNA isolation and quantitative polymerase chain reaction. Follicles were categorized as small (1–5 mm; pooled per ovary), medium (5–8 mm; individually collected), or large (8.1–17 mm; individually collected) based on surface diameter. Estradiol (E2) and progesterone (P4) levels were measured by radioimmunoassay (RIA) in FFL. Abundance of BRB messenger RNA (mRNA) in GCs was 8.6- to 11.8-fold greater (P < 0.05) in small (n = 31), medium (n = 66), and large (n = 33) subordinate E2-inactive (FFL E2 < P4) follicles than in large (n = 16) dominant E2-active (FFL E2 > P4) follicles. In the largest 4 follicles, GCs BRB mRNA abundance was negatively correlated (P < 0.01) with FFL E2 (r = −0.65) and E2:P4 ratio (r = −0.46). In experiment 2, GCs from large (8–22 mm diameter) and small (1–5 mm diameter) follicles were treated with insulin-like growth factor 1 (IGF1; 0 or 30 ng/mL) and/or tumor necrosis factor alpha (0 or 30 ng/mL); IGF1 increased (P < 0.05) BRB mRNA abundance, and tumor necrosis factor alpha decreased (P < 0.001) the IGF1-induced BRB mRNA abundance in large-follicle GCs. In experiment 3 to 6, E2, FSH, fibroblast growth factor 9, cortisol, wingless 3A, or sonic hedgehog did not affect (P > 0.10) abundance of BRB mRNA in GCs; thyroxine and LH increased (P < 0.05), whereas prostaglandin E2 (PGE2) decreased (P < 0.05) BRB mRNA abundance in small-follicle GCs. Treatment of small-follicle GCs with recombinant human RNase1 increased (P < 0.05) GCs numbers and E2 production. In conclusion, BRB is a hormonally and developmentally regulated gene in bovine GCs and may regulate E2 production during follicular growth in cattle.

      PubDate: 2015-12-04T02:12:55Z
  • Follicle-stimulating hormone–induced rescue of cumulus cell
           apoptosis and enhanced development ability of buffalo oocytes
    • Abstract: Publication date: Available online 31 October 2015
      Source:Domestic Animal Endocrinology
      Author(s): A. Jain, T. Jain, P. Kumar, M. Kumar, S. De, M. Gohain, R. Kumar, T.K. Datta
      The effect of follicle-stimulating hormone (FSH) on apoptotic status of cumulus cells, expression of proapoptotic and antiapoptotic genes, and development rate of in vitro fertilization–produced buffalo embryos were investigated. FSH supplementation in in vitro maturation–medium resulted in a dose-dependent reduction in the expression of proapoptotic genes namely, BCL2-associated X protein (BAX), cytochrome c, and caspase-3 and increase in the expression of antiapoptotic genes such as B-cell lymphoma 2 (BCL2) and X-linked inhibitor of apoptosis protein (XIAP) in cumulus cells of mature oocyte. Cumulus expansion, oocyte maturation, cleavage, and blastocyst development rates were significantly higher (P < 0.05) in 5 and 10-μg/mL FSH-supplemented groups as compared with control. Significant increase in the expression of FSH receptor messenger RNA was also found with 5 and 10-μg/mL FSH (P < 0.05). TUNEL assay confirmed that the population of apoptotic cumulus cells of matured oocytes was reduced in the FSH-treated groups as compared with control (P < 0.05). In conclusion, our data suggest that FSH may attenuate apoptosis in cumulus cells via mitochondria-dependent apoptotic pathway by increasing XIAP expression, resulting in a more favorable ratio of BCL2/BAX expression and decreasing the cytochrome c and caspase-3 expression, eventually contributing to developmental competence of oocytes. The information generated will help in improving the in vitro embryo production program in buffalo.

      PubDate: 2015-12-04T02:12:55Z
  • Prolonged hyperinsulinemia affects metabolic signal transduction markers
           in a tissue specific manner
    • Abstract: Publication date: Available online 19 November 2015
      Source:Domestic Animal Endocrinology
      Author(s): A. Campolo, M.A. de Laat, L. Keith, K.J. Gruntmeir, V.A. Lacombe
      Insulin dysregulation is common in horses although the mechanisms of metabolic dysfunction are poorly understood. We hypothesized that insulin signaling in striated (cardiac and skeletal) muscle and lamellae may be mediated through different receptors as a result of receptor content, and that transcriptional regulation of downstream signal transduction and glucose transport may also differ between tissues sites during hyperinsulinemia. Archived samples from horses treated with a prolonged insulin infusion or a balanced electrolyte solution were used. All treated horses developed marked hyperinsulinemia and clinical laminitis. Protein expression was compared across tissues for the insulin receptor and insulin-like growth factor 1 receptor (IGF-1R) by immunoblotting. Gene expression of metabolic insulin-signaling markers (insulin receptor substrate 1, Akt2, and glycogen synthase kinase 3 beta [GSK-3β]) and glucose transport (basal glucose transporter 1 and insulin-sensitive glucose transporter 4) was evaluated using real-time reverse transcription polymerase chain reaction. Lamellar tissue contained significantly more IGF-1R protein than skeletal muscle, indicating the potential significance of IGF-1R signaling for this tissue. Gene expression of the selected markers of insulin signaling and glucose transport in skeletal muscle and lamellar tissues was unaffected by prolonged hyperinsulinemia. In contrast, the significant upregulation of Akt2, GSK-3β, GLUT1, and GLUT4 gene expression in cardiac tissue suggested that the prolonged hyperinsulinemia induced an increase in insulin sensitivity and a transcriptional activation of glucose transport. Responses to insulin are tissue-specific, and extrapolation of data across tissue sites is inappropriate.

      PubDate: 2015-12-04T02:12:55Z
  • Dietary melatonin alters uterine artery hemodynamics in pregnant Holstein
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 55
      Author(s): K.E. Brockus, C.G. Hart, C.L. Gilfeather, B.O. Fleming, C.O. Lemley
      The objective was to examine uterine artery hemodynamics and maternal serum profiles in pregnant heifers supplemented with dietary melatonin (MEL) or no supplementation (CON). In addition, melatonin receptor–mediated responses in steroid metabolism were examined using a bovine endometrial epithelial culture system. Twenty singleton pregnant Holstein heifers were supplemented with 20 mg of melatonin (n = 10) or no melatonin supplementation (control; n = 10) from days 190 to 262 of gestation. Maternal measurements were recorded on days 180 (baseline), 210, 240, and 262 of gestation. Total uterine blood flow was increased by 25% in the MEL-treated heifers compared with the CON. Concentrations of progesterone were decreased in MEL vs CON heifers. Total serum antioxidant capacity was increased by 43% in MEL-treated heifers when compared with CON. Activity of cytochrome P450 1A, 2C, and superoxide dismutase was increased in bovine endometrial epithelial cells treated with melatonin, whereas the melatonin receptor antagonist, luzindole, negated the increase in cytochrome P450 2C activity. Moreover, estradiol or progesterone treatment altered bovine uterine melatonin receptor expression, which could potentiate the melatonin-mediated responses during late gestation. The observed increase in total uterine blood flow during melatonin supplementation could be related to its antioxidant properties. Compromised pregnancies are typically accompanied by increased oxidative stress; therefore, melatonin could serve as a therapeutic supplementation strategy. This could lead to further fetal programming implications in conjunction with offspring growth and development postnatally.

      PubDate: 2015-12-04T02:12:55Z
  • Myostatin inhibits porcine intramuscular preadipocyte differentiation
           in vitro
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 55
      Author(s): W.X. Sun, M.V. Dodson, Z.H. Jiang, S.G. Yu, W.W. Chu, J. Chen
      This study assessed the effect of myostatin on adipogenesis by porcine intramuscular preadipocytes. Intramuscular preadipocytes were isolated from the longissimus dorsi muscle of newborn pigs. Myostatin inhibited intramuscular preadipocyte differentiation in a dose-dependent manner. Myostatin treatment during preadipocyte differentiation significantly (P < 0.05) inhibited the expression of the adipogenic marker genes CCAAT/enhancer-binding protein β, CCAAT/enhancer-binding protein α, peroxisome proliferator-activated receptor γ, sterol regulatory element–binding protein-1c, fatty acid–binding protein, and adiponectin. Myostatin also significantly (P < 0.05) reduced the release of glycerol and decreased both adipose triglyceride lipase and hormone-sensitive lipase expression in intramuscular adipocytes. Our study suggests that myostatin acts as an extrinsic regulatory factor in regulating intramuscular adipogenesis.

      PubDate: 2015-12-04T02:12:55Z
  • The Hypothalamo-pituitary adrenal (HPA) axis in sheep is attenuated during
           lactation in response to psychosocial and predator stress
    • Abstract: Publication date: Available online 23 November 2015
      Source:Domestic Animal Endocrinology
      Author(s): C.R. Ralph, A.J. Tilbrook
      Activation of the hypothalamo-pituitary adrenal (HPA) axis by psychosocial stress is attenuated during lactation. We tested the hypothesis that lactating ewes will have attenuated HPA axis responses to isolation and restraint but will have greater responses to predator stress in the form of barking dogs. We imposed two 4 h stressors: psychosocial stress (isolation and restraint of ewes) and predator stress (barking dogs). Blood was collected i.v. every 10 min from non-lactating ewes (n = 6), lactating ewes with lambs present but not able to be suckled (n = 6) and lactating ewes with lambs present and able to be suckled (n = 6). Plasma cortisol and oxytocin were measured. For non-lactating ewes cortisol increased (P < 0.01) in response to both stressors and these increases were greater (P < 0.01) than in the lactating animals. For lactating ewes with lambs present but unable to be suckled cortisol increased (P < 0.05) in response to both stressors with a greater response to barking dogs (P < 0.05). For lactating ewes with lambs present and able to be suckled, cortisol increased (P < 0.01) in response to barking dogs only. Plasma oxytocin was greater (P < 0.01) in lactating ewes than in non-lactating ewes and did not change in response to the stressors. In conclusion, lactating ewes are likely to have a greater HPA axis response to a stressor that may be perceived to threaten the welfare of themselves and/or their offspring. The role of oxytocin in attenuation of the HPA axis to stress in sheep is unclear from the current research and requires further investigation.

      PubDate: 2015-12-04T02:12:55Z
  • Systemic effect of FSH and intraovarian effect of the corpus luteum on
           complete regression versus recovery of regressing wave-2 follicles in
    • Abstract: Publication date: Available online 26 November 2015
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, M.A.R. Siddiqui, J.M. Baldrighi, C.A. Wolf
      Each subordinate of the second follicular wave (wave 2) was monitored, and the outcome was classified as fully regressed (decreased in diameter to 2 mm) or recovered (decreased initially and then increased to become a growing follicle of the subsequent wave 1). The changing diameter of each follicle after emergence at 2 mm and plasma concentration of FSH were determined every 12 h from the day of ovulation (Day 0) to 4 d after the subsequent ovulation in heifers with 2 follicular waves per interovulatory interval (n = 10). The number and percentage of wave-2 subordinates that initially regressed and then recovered (7.2 ± 1.0 follicles; 33.2 ± 5.1%) were less (P < 0.0008) than the number and percentage that completely regressed (15.0 ± 1.7; 66.8 ± 5.1%). Follicles that later recovered initially reached maximal diameter on a later day (P < 0.0001) after emergence at 2 mm (4.3 ± 0.2 d) and at a larger (P < 0.0001) diameter (5.8 ± 0.2 mm ) than for follicles that completely regressed (3.2 ± 0.1 d; 4.7 ± 0.1 mm). The FSH surge that stimulated wave 2 began earlier and was more sustained in a subgroup with a high percentage of recovered follicles (61%) than in a subgroup with a low percentage (24%). Recovery began on Day –1.0 ± 0.1 when the follicles had regressed to 3.7 ± 0.1 mm. Diameter of subordinate follicles on Day –6 or before the expected days of luteolysis was greater (P < 0.05) when in the CL ovary than when in the nonCL ovary. During expected luteolysis, more follicles (P < 0.008) per ovary continued to regress when ipsilateral to the CL (9.2 ± 1.1 follicles) than when contralateral (5.8 ± 1.1), and more follicles (P < 0.02) recovered from regression when contralateral to the CL (5.0 ± 0.8) than when ipsilateral (2.2 ± 0.6). The hypothesis that the CL has a local effect on the development, regression, and recovery of the subordinate follicles of wave 2 was supported.

      PubDate: 2015-12-04T02:12:55Z
  • Stimulation of regressing subordinate follicles of wave 2 with a
           gonadotropin product in heifers
    • Abstract: Publication date: Available online 30 November 2015
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, M.A.R. Siddiqui, J.M. Baldrighi, M.M. Hoffman
      The recovery of regressing wave-2 subordinate follicles was studied by treating heifers with a gonadotropin product that had about 84% and 16% of FSH and LH activity, respectively. A treated group (n = 8) received a single dose of 50 mg (2.5 mL) of the gonadotropin product, and a control group (n = 8) received 2.5 mL of saline vehicle. The group assignment of heifers was not known to the ultrasonographer who tracked the follicles and measured follicle diameters. Follicle measurements began on the day of expected follicle deviation in wave 2 (largest follicle closest to 8.5 mm) and treatment (hour 0) was given on Day 13.4 ± 0.2 (Day 0 = ovulation) when the dominant follicles of waves 1 and 2 were 14.1 ± 0.3 mm and 10.7 ± 0.1 mm, respectively. Subordinate follicles of wave 2 that had regressed to a 3-mm category (3.0 to 3.9 mm) or 4-mm category by hour 0 decreased in diameter for at least 48 h before hour 0, whereas follicles that were in the 5-mm or 6-mm categories at hour 0 did not change significantly in diameter during the previous 48 h. About 55% of the follicles that had regressed to the 3-mm and 4-mm categories at hour 0 and 78% of the follicles in the 5-mm and 6-mm categories increased in diameter after gonadotropin treatment, whereas follicles in the control group continued to decrease (regress) in diameter. The follicles for each of the four diameter categories were greater (P < 0.05) in diameter 9 h after treatment in the treated group than in the control group. The dominant follicle of wave 1 and the largest subordinate follicle of wave 2 in the treated group also increased in diameter so that diameter was greater (P < 0.05) than in the controls at hour 9. The results demonstrated that subordinate follicles of wave 2 that had decreased in diameter (regressed) for at least 48 h retained the capability to recover as indicated by a diameter increase when exposed to a gonadotropin product.

      PubDate: 2015-12-04T02:12:55Z
  • Interleukin 6 increases the in vitro expression of key proteins
           associated with steroidogenesis in the bovine adrenal zona fasciculata
    • Abstract: Publication date: Available online 26 October 2015
      Source:Domestic Animal Endocrinology
      Author(s): S. McIlmoil, J. Strickland, A.M. Judd
      In this study, the in vitro effects of interleukin 6 (IL-6) on the messenger RNAs (mRNAs) and proteins for key steroidogenic factors in the bovine adrenal zona fasciculate (ZF) were determined. Bovine adrenal glands were obtained from an abattoir, and the ZF was isolated. Strips of ZF were then exposed to different concentration of murine IL-6 and/or adrenocorticotropic hormone (ACTH) for various intervals, the protein and mRNA extracted, and the mRNA and protein expression determined by RT-PCR and Western blots. Exposure (1 h) to IL-6 increased in a concentration-dependent manner (10-pg IL-6/mL, P < 0.05 vs control; 100-pg IL-6/mL, P < 0.01 vs control) the relative expression of the mRNAs and proteins for steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), 3β hydroxysteroid dehydrogenase type 2 (3β HSD), 17α-hydroxylase/17,20-lyase/17,20-desmolase (P450 17OH), steroid 21-hydroxylase (P450 21OH), steroid 11-β-hydroxylase type 1 (P450 11βOH), and steroidogenic factor 1 (SF-1), a nuclear factor that increases StAR and steroidogenic enzymes (SEs) expression. Similarly, IL-6 (10 ng/mL) increased the relative expression of proteins and mRNAs for StAR, P450scc, 3β HSD, P450 17OH, P450 21 OH, P450 11βOH, and SF-1 in a time-dependent manner (30 min, P < 0.05 vs control; 60, 120, and 240 min, P < 0.01 vs control). In contrast, IL-6 decreased in a concentration-dependent (P < 0.01 vs control for 1, 10, and 100-ng/mL IL-6) and time-dependent (P < 0.05 vs control for 30, 60,120, and 240 min of 10-ng/mL IL-6) manner the relative expression of the mRNA and protein for adrenal hypoplasia congenita-like protein (DAX-1), a nuclear factor that decreases expression of StAR and SEs. Incubation (1 h) of ZF with 100-nM ACTH increased (P < 0.05 vs control) the relative expression of StAR, P450scc, 3β HSD, P450 17OH, P450 21OH, P450 11βOH, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. Murine IL-6 (10 pg/mL) augmented (P < 0.05 vs ACTH) both the stimulatory and inhibitory effects of ACTH. Bovine IL-6 (100 pg/mL, 1-h incubation) also increased (P < 0.01 vs control) the relative expression of the proteins for StAR, P450scc, and SF-1 and decreased (P < 0.01 vs control) the relative expression of DAX-1. In summary, IL-6 increased ZF expression of StAR and 5 SEs, which may be mediated in part by decreasing DAX-1 expression and increasing SF-1 expression.

      PubDate: 2015-12-04T02:12:55Z
  • Defective secretion of PGF2α during development of idiopathic
           persistent corpus luteum in mares
    • Abstract: Publication date: Available online 28 October 2015
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, T. Castro, J.M. Baldrighi, C.A. Wolf, V.G. Santos
      Five mares that developed idiopathic persistent corpus luteum (PCL) were compared with 5 mares with apparently normal interovulatory intervals (IOIs). Progesterone (P4) and a metabolite of PGF2α (PGFM) were assayed daily beginning on the day of ovulation (Day 0). Transition between the end of an initial progressive P4 increase and the beginning of a gradual decrease in P4 occurred on mean Day 6. The gradual decrease in P4 between Days 6 and 12 was less (approached significance, P < 0.06) in the PCL group than in the IOI group. The P4 concentration on Day 12 (before luteolysis in IOI group) was greater (P < 0.05) in the PCL group than in the IOI group. In a post hoc comparison, an interaction (P < 0.04) of group by day for Days 4 to 7 indicated that the end of the progressive increase in P4 was temporally associated with a transient increase in concentration of PGFM in IOI mares but not in PCL mares. Complete luteolysis (P4 < 1 ng/mL) occurred in the IOI mares on Days 13 to 15. Partial luteolysis (mean P4 decrease, 62%) occurred in 3 of the 5 PCL mares. Normalization to the day at the end of the most pronounced P4 decrease in the IOI mares and in the 3 PCL mares with partial luteolysis resulted in a day-by-group interaction (P < 0.05) for PGFM concentration. The interaction was partly from lower PGFM concentration on the day at the end of the pronounced P4 decrease in the 3 PCL mares than in the IOI mares. The peak of a transient PGFM increase and the day at the end of the most pronounced decrease in P4 were synchronized in each IOI mare but not in any of the 3 PCL mares. In the other 2 PCL mares, partial luteolysis did not occur, and a transient increase in PGFM was not apparent. Results tentatively indicated that the relationship between P4 and PGFM may be altered as early as Day 6 in PCL mares and supported the hypothesis that PGF2α secretion is defective in mares with idiopathic PCL.

      PubDate: 2015-12-04T02:12:55Z
  • Tamoxifen impairs prepubertal mammary development and alters expression of
           estrogen receptor α (ESR1) and progesterone receptors (PGR)
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): H.L.M. Tucker, C.L.M. Parsons, S. Ellis, M.L. Rhoads, R.M. Akers
      Research has shown that prepubertal heifers experience allometric mammary growth that is influenced by the ovaries. Our purpose was to determine the role of estrogen in prepubertal mammary gland development. Sixteen Holstein calves were randomly assigned to 1 of 2 treatment groups: tamoxifen-injected (TAM) or control (CON). Calves were administered the antiestrogen tamoxifen (0.3 mg kg1 d1) or placebo from 28 to 120 d of age. At 120 d, calves were euthanized and udders removed. Weight and DNA content of trimmed parenchymal tissue were halved (P ≤ 0.0001) in TAM compared with CON calves. Parenchymal samples from 3 zones of the left rear mammary gland (lower, middle, and outer regions) were processed for immunohistochemical staining for estrogen receptor α (ESR1) and progesterone receptor (PGR), Ki67-positive cells, and 5-bromo-2'-deoxyuridine label retaining cells (LRCs). Overall, neither the percentage nor location within the epithelial tissue layer of either ESR1- or PGR-positive cells was impacted by TAM treatment. However, image analysis indicated a 6.2-fold lower (P = 0.0001) level of ESR1 protein expression in TAM calves. Similarly, messenger RNA expression of ESR1 was also reduced (P = 0.0001) in TAM heifers. In contrast, expression of PGR protein was greater by 43% (P = 0.03) in TAM calves, but messenger RNA expression did not differ between treatments. Overall, TAM calves had a higher (P ≤ 0.03) percentage and density (cells per tissue area) of Ki67-positive cells. Irrespective of treatment, there were also more Ki67-labeled cells in the outer zones of the mammary gland (P ≤ 0.001). We were able to effectively use multispectral imaging to identify positive cells and quantify the expression of ESR1 and PGR protein. We also identified and counted the proportion of label retaining cells (LCR) (putative epithelial stem cells). We noted an overall 2.9-fold greater number of LRCs in TAM heifers and more LRCs in the outer sampling zones. This suggests that a cohort of LCR cells in TAM remained inactivated in comparison with CON heifers, which exhibited markedly increased growth of the mammary parenchymal tissue over the treatment period. These results suggest that the impacts of ovariectomy are partially explained by loss of ESR1 expression and/or estrogen receptor signaling in the prepubertal bovine mammary gland. The significance of mammary expression of PGR in control of prepubertal bovine mammary development remains unresolved.

      PubDate: 2015-12-04T02:12:55Z
  • Circulating concentrations of glucagon-like peptide 1, glucose-dependent
           insulinotropic peptide, peptide YY, and insulin in client-owned lean,
           overweight, and diabetic cats
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): C.J. McMillan, R.C. Zapata, P.K. Chelikani, E.C.R. Snead, K. Cosford
      Our objectives were to measure plasma concentrations of glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) in client-owned newly diagnosed diabetic cats and nondiabetic lean or overweight cats and to determine whether circulating concentrations of these hormones differed between study groups and if they increased postprandially as seen in other species. A total of 31 cats were recruited and placed into 1 of 3 study groups: lean (body condition score 4–5 on a scale of 1–9; n = 10), overweight (body condition score 6–8; n = 11), or diabetic (n = 10). Diabetics were newly diagnosed and had not had prior insulin therapy. Preprandial (fasting) and postprandial (60 min after meal) plasma hormone and glucose concentrations were measured at baseline and 2 and 4 wk. All cats were exclusively fed a commercially available high-protein and low-carbohydrate diet commonly prescribed to feline diabetic patients for 2 wk before the 2-wk assessment and continued through the 4-wk assessment. Results showed that plasma concentrations of GLP-1, GIP, PYY, and insulin increased in general after a meal in all study groups. Plasma PYY concentrations did not differ (P > 0.10) between study groups. Diabetics had greater plasma concentrations of GLP-1 and GIP compared with the other study groups at baseline (P < 0.05), and greater preprandial and postprandial GLP-1 concentrations than lean cats at 2 and 4 wk (P < 0.05). Preprandial plasma GIP concentrations were greater in diabetics than obese and lean (P < 0.05) cats at week 4. Postprandial plasma GIP concentrations in diabetics were greater than lean (P < 0.05) at week 2 and obese and lean cats (P < 0.05) at week 4. Together, our findings suggest that diabetic status is an important determinant of circulating concentrations of GLP-1 and GIP, but not PYY, in cats. The role of GLP-1, GIP, and PYY in the pathophysiology of feline obesity and diabetes remains to be determined.

      PubDate: 2015-12-04T02:12:55Z
  • MicroRNA-10b suppresses goat granulosa cell proliferation by targeting
           brain-derived neurotropic factor
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): J.Y. Peng, X.P. An, F. Fang, K.X. Gao, H.Y. Xin, P. Han, L.J. Bao, H.D. Ma, B.Y. Cao
      Brain-derived neurotropic factor (BDNF) and its high-affinity receptor, tyrosine kinase receptor B, have been assumed to be involved in female reproduction and have recently shown to play an essential role in follicle activation and oocyte maturation. In this study, we analyzed the expression of miR-10b and BDNF in the ovary and discovered that the expression of miR-10b was higher in monotocous goat ovaries than in polytocous goat ovaries, whereas the expression pattern of BDNF in ovary was opposite. Moreover, human chorionic gonadotropin induced rapid and transient expression of BDNF messenger RNA and protein. In contrast, human chorionic gonadotropin upregulated miR-10b expression in a time-dependent manner. The BDNF gene was identified as a direct target of miR-10b using a dual-luciferase reporter assay. Transfection of granulosa cells with miR-10b decreased BDNF messenger RNA and protein levels. MiR-10b overexpression inhibited cell proliferation, whereas BDNF promoted cell proliferation. However, a combined treatment with miR-10b and BDNF promoted cell proliferation, indicating that the reintroduction of BDNF reversed the suppressive effect of miR-10b. These results demonstrate that miR-10b downregulates BDNF expression in granulosa cells by directly targeting the 3′ untranslated regions and plays an important role in inhibiting granulosa cell proliferation by targeting BDNF.

      PubDate: 2015-12-04T02:12:55Z
  • Protein and mRNA expression of interleukin 1 system members in bovine
           ovarian follicles and effects of interleukin -1β on primordial
           follicle activation and survival in vitro
    • Abstract: Publication date: Available online 5 October 2015
      Source:Domestic Animal Endocrinology
      Author(s): J.R.S. Passos, J.J.N. Costa, E.V. da Cunha, A.W.B. Silva, R.P. Ribeiro, G.B. de Souza, P.A.A. Barroso, A.M.P. Dau, M.V.A. Saraiva, P.B.D. Gonçalves, R. van den Hurk, J.R.V. Silva
      This study aimed to investigate the expression of interleukin 1 system members (proteins and mRNA of ligands and receptors) and its distribution in ovarian follicles of cyclic cows, as well as to evaluate the effects of interleukin-1β (IL-1β) on the survival and activation of primordial follicles in vitro. The ovaries were processed for localization of interleukin 1 system in preantral and antral follicles by immunohistochemical, real time PCR and western blot analysis. For in-vitro studies, ovarian fragments were cultured in α-MEM+ supplemented with IL-1β (0, 1, 10, 50 or 100 ng/mL), and after 6 days the cultured tissues were processed for histological analysis. Immunohistochemical results showed that the interleukin 1 system proteins IL-1β, IL-1RA, IL-1RI and IL-1RII were detected in the cytoplasm of oocytes and granulosa cells from all follicular categories, and theca cells of antral follicles. Variable levels of mRNA for the interleukin 1 system members were observed at different stages of development. After 6 days of culture, the presence of IL-1β (10 or 50 ng/mL) was effective in maintaining the percentage of normal follicles and in promoting primordial follicle activation. In conclusion, interleukin 1 system members are differentially expressed in ovarian follicles according to their stage of development. Moreover, IL-1β promotes the development of primordial follicles. These results indicate an important role of the interleukin 1 system in the regulation of bovine folliculogenesis.

      PubDate: 2015-10-07T14:01:23Z
  • Studies on lysophosphatidic acid action during in vitro
           preimplantation embryo development
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): D. Boruszewska, E. Sinderewicz, I. Kowalczyk-Zieba, K. Grycmacher, I. Woclawek-Potocka
      Assisted reproductive technologies, including in vitro embryo production (IVP), have been successfully used in animal reproduction to optimize breeding strategies for improved production and health in animal husbandry. Despite the progress in IVP techniques over the years, further improvements in in vitro embryo culture systems are required for the enhancement of oocyte and embryo developmental competence. One of the most important issues associated with IVP procedures is the optimization of the in vitro culture of oocytes and embryos. Studies in different species of animals and in humans have identified important roles for receptor-mediated lysophosphatidic acid (LPA) signaling in multiple aspects of human and animal reproductive tract function. The data on LPA signaling in the ovary and uterus suggest that LPA can directly contribute to embryo–maternal interactions via its influence on early embryo development beginning from the influence of the ovarian environment on the oocyte to the influence of the uterine environment on the preimplantation embryo. This review discusses the current status of LPA as a potential supplement in oocyte maturation, fertilization, and embryo culture media and current views on the potential involvement of the LPA signaling pathway in early embryo development.

      PubDate: 2015-09-25T13:43:18Z
  • Editorial Board
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53

      PubDate: 2015-09-25T13:43:18Z
  • Contents
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53

      PubDate: 2015-09-25T13:43:18Z
  • Ovarian stimulation with human chorionic gonadotropin and equine chorionic
           gonadotropin affects prostacyclin and its receptor expression in the
           porcine oviduct
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): I. Małysz-Cymborska, A. Andronowska
      Prostaglandins are well-known mediators of crucial events in the female reproductive tract, eg, early embryo development and implantation. Prostacyclin (PGI2) is the most synthesized prostaglandin in the human oviduct during the postovulatory period, indicating its important role in supporting and regulating the oviductal environment. The present study was undertaken to determine the influence of insemination and ovarian stimulation with human chorionic gonadotropin (hCG)/equine chorionic gonadotropin (eCG) on PGI2 synthesis in the porcine oviduct on day 3 post coitus. Mature gilts (n = 25) were assigned into 2 experiments. In experiment I, gilts were divided into cyclic (control; n = 5) and inseminated (control; n = 5) groups. In experiment II, there were 3 groups of animals: inseminated (n = 5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n = 5), and superovulated/inseminated (1,500 IU eCG, 1,000 IU hCG; n = 5) gilts. Parts of oviducts (isthmus and ampulla) were collected 3 days after phosphate-buffered saline treatment (cyclic gilts of experiment I) or insemination (all other groups). Expression of messenger RNA for PGI2 synthase (PGIS) and its receptor (IP) was measured by real-time reverse transcription polymerase chain reaction (real-time RT PCR) and protein levels using Western blots. Concentrations of the PGI2 metabolite 6-keto PGF1α were evaluated by enzyme immunoassay and localization of PGIS and IP in the oviductal tissues using immunohistochemical staining. Insemination by itself increased PGIS protein levels in the oviductal isthmus (P < 0.05) and IP protein expression in the ampulla (P < 0.05). The concentration of 6-keto PGF1α increased significantly in the oviductal ampulla after insemination (P < 0.05). Induction of ovulation decreased IP protein levels in the oviductal ampulla (P < 0.05), whereas superovulation reduced IP levels in both parts of the oviduct (P < 0.01). Synthesis of 6-keto PGF1α was reduced by induction of ovulation and by superovulation in the oviductal ampulla (P < 0.05). Immunohistochemical staining confirmed the presence of PGIS in the muscular layer of the isthmus and both mucosa and muscular layers of the ampulla. IP-positive cells were observed in both mucosal and muscular layers of the isthmus and ampulla. This study showed for the first time that PGI2 synthesis and IP expression are insemination dependent. Moreover, ovarian stimulation with hCG/eCG decreases IP expression and 6-keto PGF1α concentrations in porcine oviducts. Therefore, disturbances in PGI2/IP expression and synthesis may lead to disruption of the oviductal environment and, in turn, perturbed development of embryos and their transport to the uterus.

      PubDate: 2015-09-25T13:43:18Z
  • Differential metabolic and endocrine adaptations in llamas, sheep, and
           goats fed high- and low-protein grass-based diets
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): A. Kiani, L. Alstrup, M.O. Nielsen
      This study aimed to elucidate whether distinct endocrine and metabolic adaptations provide llamas superior ability to adapt to low protein content grass-based diets as compared with the true ruminants. Eighteen adult, nonpregnant females (6 llamas, 6 goats, and 6 sheep) were fed either green grass hay with (HP) or grass seed straw (LP) in a cross-over design experiment over 2 periods of 21 d. Blood samples were taken on day 21 in each period at −30, 60, 150, and 240 min after feeding the morning meal and analyzed for plasma contents of glucose, triglyceride, nonesterified fatty acids, β-hydroxy butyrate (BOHB), urea, creatinine, insulin, and leptin. Results showed that llamas vs sheep and goats had higher plasma concentrations of glucose (7.1 vs 3.5 and 3.6 ± 0.18 mmol/L), creatinine (209 vs 110 and 103 ± 10 μmol/L), and urea (6.7 vs 5.6 and 4.9 ± 0.5 mmol/L) but lower leptin (0.33 vs 1.49 and 1.05 ± 0.1 ng/mL) and BOHB (0.05 vs 0.26 and 0.12 ± 0.02 mmol/L), respectively. BOHB in llamas was extremely low for a ruminating animal. Llamas showed that hyperglycemia coexisted with hyperinsulinemia (in general on the HP diet; postprandially on the LP diet). Llamas were clearly hypercreatinemic compared with the true ruminants, which became further exacerbated on the LP diet, where they also sustained plasma urea at markedly higher concentrations. However, llamas had markedly lower leptin concentrations than the true ruminants. In conclusion, llamas appear to have an intrinsic insulin resistant phenotype. Augmentation of creatinine and sustenance of elevated plasma urea concentrations in llamas when fed the LP diet must reflect distinct metabolic adaptations of intermediary protein and/or nitrogen metabolism, not observed in the true ruminants. These features can contribute to explain lower metabolic rates in llamas compared with the true ruminants, which must improve the chances of survival on low protein content diets.

      PubDate: 2015-09-25T13:43:18Z
  • Photoperiod affects the cerebrospinal fluid proteome: a comparison
           between short day– and long day–treated ewes
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): A.-P. Teixeira-Gomes, G. Harichaux, D. Gennetay, J. Skipor, J.-C. Thiery, V. Labas, L. Dufourny
      Photoperiod is the main physical synchronizer of seasonal functions and a key factor in the modulation of molecule access to cerebrospinal fluid (CSF) in animals. Previous work has shown that photoperiod affects the transfer rate of steroids and protein hormones from blood to CSF and modulates choroid plexus tight junction protein content. We hypothesized that the CSF proteome would also be modified by photoperiod. We tested this hypothesis by comparing CSF obtained from the third ventricle of mature, ovariectomized, estradiol-replaced ewes exposed to long day length (LD) or short day length (SD). Variations in CSF protein expression between SD- or LD-treated ewes were studied in pools of CSF collected for 48 h. Proteins were precipitated, concentrated, and included in a polyacrylamide gel without protein fractionation. After in-gel tryptic digestion of total protein samples, we analyzed the resulting peptides by nanoliquid chromatography coupled with high-resolution tandem mass spectrometry (GeLC-MS/MS). Quantitative analysis was performed using 2 methods based on spectral counting and extracted ion chromatograms. Among 103 identified proteins, 41 were differentially expressed between LD and SD ewes (with P < 0.05 and at least a 1.5-fold difference). Of the 41 differentially expressed proteins, 22 were identified by both methods and 19 using extracted ion chromatograms only. Eighteen proteins were more abundant in LD ewes and 23 were more abundant in SD ewes. These proteins are involved in numerous functions including hormone transport, immune system activity, metabolism, and angiogenesis. To confirm proteomic results, 2 proteins, pigment epithelium-derived factor (PEDF) and gelsolin, for each individual sample of CSF collected under SD or LD were analyzed with Western blots. These results suggest an important photoperiod-dependent change in CSF proteome composition. Nevertheless, additional studies are required to assess the role of each protein in seasonal functions.

      PubDate: 2015-09-25T13:43:18Z
  • Plasma anti-Müllerian hormone as a predictive endocrine marker to
           select Bos taurus (Holstein) and Bos indicus (Nelore) calves for
           in vitro embryo production
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): E.O.S. Batista, B.M. Guerreiro, B.G. Freitas, J.C.B. Silva, L.M. Vieira, R.M. Ferreira, R.G. Rezende, A.C. Basso, R.N.V.R. Lopes, F.P. Rennó, A.H. Souza, P.S. Baruselli
      This study evaluated the association between plasma anti-Müllerian hormone (AMH) concentrations and in vitro embryo production in Bos indicus (Nelore; experiment 1) and Bos taurus (Holstein; experiment 2) calves superstimulated or not with 140 mg of porcine follicle-stimulating hormone (pFSH; 4 decreasing doses twice daily). Oocytes were recovered from calves aged 2 to 4 mo after receiving gonadotropin stimulation (Nelore, n = 15; Holstein, n = 12) or not (Nelore, n = 15; Holstein, n = 12). Cycling heifers formed a positive control group (n = 15 for Nelore [aged 18–24 mo], n = 10 for Holstein [aged 14–16 mo]). All the calves underwent laparoscopic ovum pickup, and cycling heifers underwent a regular transvaginal ultrasound-guided ovum pickup for oocyte recovery. Immediately before oocyte retrieval, blood samples were taken for subsequent AMH determination (ng/mL). Regardless of the genetic group, calves that received pFSH (3.6 ± 1.1 in Nelore and 4.6 ± 1.2 in Holstein) or did not receive pFSH (3.2 ± 1.0 in Nelore and 2.5 ± 0.8 in Holstein) had greater plasma AMH concentrations (P = 0.01 in Nelore and P = 0.003 in Holstein) than cycling heifers (1.1 ± 0.2 in Nelore and 0.6 ± 0.07 in Holstein). AMH concentrations in calves with or without pFSH were similar in both genetic groups (3.6 ± 1.1 vs 3.2 ± 1.0 in Nelore; 4.6 ± 1.2 vs 2.5 ± 0.8 in Holstein). In calves, positive correlations were observed between plasma AMH concentrations and the numbers of follicles >2 mm (r = 0.86, P < 0.0001 in Nelore; r = 0.78, P < 0.0001 in Holstein), cumulus-oocyte complexes (COCs) retrieved (r = 0.91, P < 0.0001 in Nelore; r = 0.82, P < 0.0001 in Holstein), COCs cultured (r = 0.71, P < 0.0001 in Nelore; r = 0.79, P < 0.0001 in Holstein), and blastocysts produced (r = 0.62, P = 0.0003 in Nelore; r = 0.58, P = 0.009 in Holstein), and these results were independent of pFSH treatment. In conclusion, calves had greater plasma AMH concentrations than cycling heifers. In addition, treatment with pFSH did not influence AMH concentrations in calves, regardless of the genetic group. More importantly, plasma AMH concentrations were positively correlated with the antral follicle population and the number of COCs retrieved, COCs cultured, and blastocysts produced in B indicus and B taurus calves. Therefore, AMH is a promising tool for selecting oocyte donor calves to maximize results during in vitro embryo production.

      PubDate: 2015-09-25T13:43:18Z
  • Potential role for GnRH in the synchronization of follicular emergence
           before the superovulatory Day 0 protocol
    • Abstract: Publication date: January 2016
      Source:Domestic Animal Endocrinology, Volume 54
      Author(s): M.F.A. Balaro, J.F. Fonseca, T.G.B. Barbosa, J.M.G. Souza-Fabjan, L.M. Figueira, T.A. Teixeira, L.R. Carvalheira, F.Z. Brandão
      The ability of gonadotropin-releasing hormone (GnRH) to synchronize ovulation and new follicular wave emergence before a “superovulatory Day 0” protocol was assessed in Santa Inês ewes. For estrus synchronization, a 60-mg medroxyprogesterone acetate sponge was inserted for 6 d. One day before sponge removal, 37.5-μg d-cloprostenol and 300 IU equine chorionic gonadotropin were injected intramuscularly (i.m.). After sponge removal, ewes were assigned to the following 3 groups: (1) GC—1 mL saline at 12 h (n = 10); (2) G24h—0.025-mg lecirelin (GnRH agonist) i.m. at 24 h (n = 10); or (3) G36h—0.025-mg lecirelin i.m. at 36 h (n = 9). Ovarian ultrasonography was conducted to assess follicular dynamics. Blood was collected to determine plasma concentrations of progesterone and estradiol. Females from G36h and GC had a greater (P < 0.05) estrous response than those from the G24h group (78.0 and 90.0 vs 0.0%, respectively). Ewes from G24h and G36h had earlier (P < 0.05) ovulation (48.0 ± 10.2 and 56.7 ± 5.7 h) compared with those from Gc (64.1 ± 9.7 h). The mean number of ovulations per ewe was greater (P < 0.05) in Gc (1.9 ± 0.6) and G36h (2.0 ± 1.0) than G24h (1.2 ± 0.4). Plasma concentrations of progesterone and estradiol differed over time. Follicular growth during the postovulatory day was affected (P < 0.05) by day of the estrus cycle as well as by the interaction (P < 0.05) of treatment and day of the estrus cycle. There was a larger (P < 0.05) population of medium follicles during the first 24 h after the ovulation in G24h compared with Gc, and there was an absence of large follicles in G36h between 36 and 72 h after ovulation. In conclusion, the use of GnRH agonist at 36 h more efficiently synchronized ovulation and promoted the absence of dominant follicles during early diestrus and may be used at the start of superovulatory treatment at 80 h in Santa Inês ewes.

      PubDate: 2015-09-25T13:43:18Z
  • Salsolinol: a potential modulator of the activity of the
           hypothalamic–pituitary–adrenal axis in nursing and postweaning
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): M. Hasiec, A.P. Herman, T. Misztal
      The most well-known physiological action of salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline) is the stimulation of prolactin secretion, especially during lactation. In addition, our recent work demonstrated that salsolinol inhibits the stress-induced activity of the hypothalamic–pituitary–adrenal (HPA) axis in lactating sheep. Here, we investigated whether salsolinol regulates the basal activity of the HPA axis in lactating sheep and whether its inhibitory action on the stress-induced activity of the HPA axis is present during the postweaning period. The first experiment was performed during the fifth week of lactation, in which unstressed sheep received an intracerebroventricular infusion of an antagonistic analogue of salsolinol, 1-MeDIQ (1-methyl-3,4-dihydroisoquinoline). Simultaneously, the infundibular nucleus and/or median eminence was perfused using the push–pull method. Sheep that received 1-MeDIQ infusion showed significantly higher concentration of plasma ACTH during the second, third, and fourth hour (P < 0.001, P < 0.01, and P < 0.001, respectively) and cortisol during the third and fourth hour (P < 0.001 and P < 0.01, respectively) than did sheep that received control infusion. There was no significant difference in the mean perfusate corticotropin-releasing hormone concentration between the 1-MeDIQ and control treatments. In the second experiment, sheep received an intracerebroventricular infusion of salsolinol during the ninth week of lactation and 48 h after lamb weaning. A comparison between the control groups in the first and second experiments revealed that sheep after weaning (ninth week of lactation) had significantly higher mean ACTH (P < 0.001) and cortisol (P < 0.001) concentrations during the first 2 h of the experiment than the nursing females (fifth week of lactation) had. Salsolinol significantly reduced the increased concentrations of ACTH and cortisol (P < 0.01) in sheep after lamb weaning. However, there was no difference in the expression of proopiomelanocortin messenger RNA within the anterior pituitary between the control and salsolinol-treated groups. In conclusion, salsolinol regulates the basal activity of the HPA axis in lactating sheep. In addition, the HPA axis of postweaning females is more sensitive to stressors associated with the experimental procedures, and salsolinol attenuates ACTH and cortisol release in this phenomenon.

      PubDate: 2015-09-25T13:43:18Z
  • Relative prolactin-to-progesterone concentrations around farrowing
           influence colostrum yield in primiparous sows
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): F. Loisel, C. Farmer, H. van Hees, H. Quesnel
      In swine, colostrum production is induced by the drop of progesterone (P4) concentrations which leads to the prepartum peak of prolactin (PRL). PRL regulates mammary cell turnover and stimulates lacteal nutrient synthesis. P4 inhibits PRL secretion and downregulates the PRL receptor in the mammary gland. The aim of the present study was to determine if the relative prepartum concentrations of P4 and PRL (PRL/P4 ratio) influence sow colostrum production. The performance of 29 Landrace × Large White primiparous sows was analyzed. Colostrum yield was estimated during 24 h starting at the onset of parturition (T0) using litter weight gains. Colostrum was collected at T0 and 24 h later (T24). Repeated jugular blood samples were collected during the peripartum period, that is, from −72 to +24 h related to farrowing and were assayed for P4 and PRL. Sows were retrospectively categorized in 2 groups according to their PRL/P4 ratio 24 h before farrowing being either <2 (low PRL/P4, n = 16) or >3 (high PRL/P4, n = 13). During the peripartum period, the circulating concentrations of P4 were lower (P < 0.05) and those of PRL tended to be greater (P < 0.10) in high PRL/P4 compared with low PRL/P4 sows. Colostrum yield was greater in high PRL/P4 compared with low PRL/P4 sows (4.11 vs 3.48 kg [root mean square error = 0.69], P < 0.05). Colostrum composition (dry matter, energy, protein, lipid, and lactose contents) and IgG and IgA concentrations did not differ between the 2 groups of sows (P > 0.10). The Na/K ratio in colostrum 24 h after the onset of farrowing was lower in high PRL/P4 compared with low PRL/P4 sows (P < 0.05). Piglet mortality between birth and T24 averaged 10.0% in low PRL/P4 litters and 7.0% in high PRL/P4 litters (P = 0.29). In conclusion, a greater PRL/P4 ratio 24 h prepartum, characterized by lower P4 concentrations and a trend for greater PRL concentrations peripartum, led to increased colostrum yield in primiparous sows.

      PubDate: 2015-09-25T13:43:18Z
  • Role of the serotonergic axis in the reproductive failure associated with
           aging broiler breeder roosters
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): N. Avital-Cohen, R. Heiblum, A. Rosenstrauch, Y. Chaiseha, N. Mobarkey, M. Gumułka, I. Rozenboim
      Reproductive failure associated with aging is a well-known phenomenon. However, the mechanism by which this failure occurs in broiler breeder roosters is still unclear. A previous study conducted in our laboratory, comparing young and aging broiler breeder roosters, demonstrated an elevation in hypothalamic vasoactive intestinal peptide (VIP) and pituitary prolactin (PRL) gene expression accompanied by a deterioration of gonadal axis function. This resulted in a decrease in semen-quality variables as roosters aged. The objective of this study was to examine the involvement of the serotonergic axis in the age-associated reproductive failure in broiler breeder roosters. Cobb roosters aged 64 wk were divided into 3 groups (n = 20 each): parachlorophenylalanine (PCPA) administration, active immunization against chicken VIP, and controls. At 69 wk of age, each group was divided into 2 equal subgroups: 1 received ovine PRL and the other served as controls. Weekly semen volume, concentration and motility, and plasma testosterone, estradiol, and PRL concentrations were examined. At the end of the experiment, roosters were euthanized, testes were weighed, and hypothalamus and pituitary were removed to assay the expression of genes encoding hypothalamic GnRH-I, pituitary FSH, pituitary LH, hypothalamic VIP, and pituitary PRL. Both PCPA administration and active immunization against chicken VIP significantly increased testis weight, semen volume, sperm concentration, ejaculation grade, plasma testosterone level, and GnRH-I, FSH and LH gene expression compared with controls (P ≤ 0.05). In addition, a decrease in plasma estradiol and PRL concentrations and VIP and PRL gene expression was observed in PCPA- and VIP-immunized birds compared with controls (P ≤ 0.05). Administration of PRL in all groups decreased gonadal axis function and semen-quality variables (P ≤ 0.05). Collectively, these results suggest that the increasing expression levels of the serotonergic axis in aging broiler breeder roosters inhibit proper gonadal function and reproductive performance. This article establishes for the first time the inhibitory role of serotonin on reproduction in aging roosters.

      PubDate: 2015-09-25T13:43:18Z
  • ACTH administration during formation of preovulatory follicles impairs
           steroidogenesis and angiogenesis in association with ovulation failure in
           lactating cows
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): D. Biran, R. Braw-Tal, M. Gendelman, Y. Lavon, Z. Roth
      Ovulation failure, follicular persistence, and formation of follicular cysts are known to impair dairy cow fertility. Although the underlying mechanism is not entirely clear, stress-induced alteration in adrenal hormone secretion can cause these ovarian pathologies. Six synchronized lactating cows were scanned daily by ultrasound, and plasma samples were taken throughout the estrous cycle. Treatment cows (n = 3) were administered with ACTH analog every 12 h from day 15 to day 21 of the cycle to induce formation of follicular cysts. Ovaries were collected at the slaughterhouse on day 23 of the cycle before appearance of follicular pathologies. Control cows (n = 3) were administered placebo, resynchronized, and administered PGF2α on day 6 of the new cycle to induce development of a preovulatory follicle. Follicular fluid was aspirated from the preovulatory follicles of each group to determine their steroid milieu. Slices were taken from the follicular wall for total messenger (m) RNA isolation and semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Administration of ACTH increased (P < 0.02) plasma cortisol concentration and reduced (P < 0.01) milk production. Androstenedione and estradiol concentrations in the follicular fluids were lower (P < 0.05) in ACTH-treated follicles than those in controls. The mRNA expression of luteinizing hormone receptor, 3β-hydroxysteroid dehydrogenase, cytochrome P450 aromatase (P450arom ), and cytochrome P450 17α-hydroxylase (P450c17 ) were lower (P < 0.02) in the ACTH-treated vs control cows. On the other hand, the expression of steroidogenic acute regulatory protein and cytochrome P450 side-chain cleavage did not differ between groups. In addition, mRNA expression of vascular endothelial growth factor (VEGF) 120 and VEGF 164 was higher (P < 0.01) in control than in ACTH-treated follicles, but that for angiopoietin-1 and 2 did not differ between groups. Findings indicated that ACTH administration throughout preovulatory follicle development alters follicular steroidogenesis in association with impaired angiogenesis. Such alterations might explain, in part, the mechanism underlying ovulation failure and the formation of persistent or cystic follicles under stress.

      PubDate: 2015-09-25T13:43:18Z
  • Placental development during early pregnancy in sheep: estrogen and
           progesterone receptor messenger RNA expression in pregnancies derived from
           in vivo–produced and in vitro–produced embryos
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): L.P. Reynolds, J.S. Haring, M.L. Johnson, R.L. Ashley, D.A. Redmer, P.P. Borowicz, A.T. Grazul-Bilska
      Sex steroids are important regulators of angiogenesis and growth in reproductive tissues, including the placenta. In experiment (exp.) 1, to examine the expression of a suite of sex steroid receptors throughout early pregnancy, maternal (caruncular [CAR]) and fetal (fetal membranes [FM]) placental tissues were collected on days 14 to 30 after mating and on day 10 after estrus (nonpregnant controls). In exp. 2, to examine the hypothesis that assisted reproductive technology would affect the expression of the same suite of sex steroid receptors, pregnancies were achieved through natural mating (NAT) or transfer of embryos from natural mating (NAT-ET), in vitro fertilization (IVF), or in vitro activation (IVA), and CAR and FM were collected on day 22. In exp. 1, for CAR messenger RNA (mRNA) expression of estrogen receptors (ESR) 1 and 2, nuclear (n) progesterone receptors (PGR) and membrane (m) PGRα, β, and γ were affected (P < 0.02) by pregnancy stage, as were ESR1, nPGR, and mPGRα, β, and γ for FM (P < 0.03). In exp. 2, for CAR, mRNA expression of ESR1 and nPGR was decreased (P < 0.001) in NAT-ET, IVF, and IVA groups compared with NAT. For FM, mRNA expression of ESR1 tended to be greater (P = 0.10) in the IVA group compared with NAT and NAT-ET, and GPER1 was greater (P < 0.05) in NAT-ET and IVF compared with NAT. These data establish the normal pattern of sex steroid receptor mRNA expression in maternal and fetal placenta during early pregnancy in sheep, and in addition, suggest that altered expression of placental sex steroid receptors may be an early event leading to poor placental vascularization and growth after assisted reproductive technology.

      PubDate: 2015-09-25T13:43:18Z
  • Relationship of adiponectin and its multimers to metabolic indices in cats
           during weight change
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): A.L. Witzel, C.A. Kirk, S.A. Kania, J.W. Bartges, R.C. Boston, T. Moyers, H. Byrd, S. Lauten
      Adiponectin is an important anti-inflammatory hormone secreted from adipose tissue. The high-molecular-weight form of adiponectin (HMW) closely correlates with insulin sensitivity in human beings. This study uses a novel method of size-exclusion gel chromatography combined with enzyme-linked immunosorbent assay to measure HMW feline adiponectin and determine its relationship to leptin, cholesterol, and insulin sensitivity as cats gain and lose weight. In addition, total adiponectin and its messenger RNA expression in subcutaneous adipose tissue were measured. No correlations were found between total serum adiponectin and subcutaneous adipose messenger RNA expression, fat mass, or measures of insulin sensitivity. This study demonstrates that cats have high percentages of HMW adiponectin. Although weak correlations between HMW adiponectin and fat mass were detected, additional cats are needed to determine if the correlations are significant.

      PubDate: 2015-09-25T13:43:18Z
  • Twenty-four-hour profiles of metabolic and stress hormones in sheep
           selected for a calm or nervous temperament
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): S.E. Rietema, M.A. Blackberry, S.K. Maloney, G.B. Martin, P.A.R. Hawken, D. Blache
      Even in the absence of stressors, temperament is associated with changes in the concentration of stress-responsive hormones and, possibly because of such changes, temperament can affect metabolism. We tested whether, in sheep bred for temperament for 14 generations, “nervous” females have greater concentrations of stress-responsive hormones in the absence of stressors than “calm” females, and whether these differences are associated with changes in the concentrations of metabolic hormones. In resting “calm” (n = 8) and “nervous” (n = 8) sheep, concentrations of cortisol, prolactin, leptin, and insulin were measured in blood plasma sampled via jugular catheter every 20 min for 24 h. The animals were individually penned, habituated to their housing and human handling over 7 wk, and fed before sampling began. Diurnal variation was evident for all hormones, but a 24-h cortisol pattern was detected in only 7 individuals. There was no effect of temperament on any aspect of concentrations of cortisol or prolactin, but “calm” animals had greater concentrations of insulin in the early afternoon than “nervous” animals (14.5 ± 1.1 vs 10.0 ± 1.6 μU/mL; P = 0.038), and a similar tendency was seen for leptin (P = 0.092). We conclude that selection for temperament affects the concentration of metabolic hormones in the absence of stressors, but this effect is independent of stress-responsive hormones.

      PubDate: 2015-09-25T13:43:18Z
  • Characterization of the hydroxycarboxylic acid receptor 2 in cats
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): E.C. Graff, O.C. Norris, M. Sandey, R.J. Kemppainen, R.L. Judd
      The hydroxycarboxylic acid receptor 2 (HCA2) belongs to a family of nutrient-sensing receptors that bind β-hydroxybutyrate, an alternative fuel source produced during a negative energy balance. The HCA2 receptor has not been identified or characterized in cats. Therefore, the following were the objectives of this study: (1) identify the feline HCA2 receptor protein sequence and compare against known human and rodent sequences, (2) determine tissue distribution and relative expression in lean, healthy cats, and (3) demonstrate in vitro functionality in feline adipose tissue. Tissues (n = 6) and primary adipocytes (n = 4) were collected from lean, healthy, female cats. The published genomic sequence for cats was used to design primers for polymerase chain reaction isolation of HCA2. Relative tissue distribution was evaluated using reverse transcriptase-polymerase chain reaction with RNA isolated from 9 different tissues (spleen, pancreas, lymph node, jejunum, kidney, liver, heart, and subcutaneous and abdominal adipose tissue). Receptor function was evaluated in primary feline adipocyte culture, and changes were compared with basal lipolysis. The in silico predicted feline HCA2 protein sequence exhibited 83.1% and 86.5% amino acid similarity to human and mouse sequences, respectively. The feline HCA2 receptor is predominantly expressed in adipose tissue and spleen. Exposure of feline adipocytes to niacin, a pharmacologic ligand of HCA2, inhibited lipolysis to a similar degree as insulin, a potent lipolytic inhibitor. In conclusion, the feline HCA2 receptor is similar to human and murine receptors in sequence, distribution, and functionality. By gaining a better understanding of the HCA2 receptor in cats, we will be able to better manage feline patients.

      PubDate: 2015-09-25T13:43:18Z
  • Experimental hyperlipidemia induces insulin resistance in sheep
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): H. Akbari, B. Dalir-Naghadeh, S. Asri-Rezaei, M. Hadian, R.C. Boston
      This study aimed to evaluate the effects of intravenous infusion of a soybean-based lipid emulsion on some blood energy–related metabolites and insulin sensitivity indexes in sheep. Four clinically healthy ewes were assigned into a 2-treatment, 2-period cross-over design. Either normal saline (NS) or lipid emulsion (LE) was intravenously introduced at a rate of 0.025 mL·kg−1 min−1 for 6 h. The concentrations of blood nonesterified fatty acid (NEFA), beta-hydroxybutyrate, triglyceride, cholesterol, urea, creatinine, cortisol, glucose, and insulin were measured at different time points. After 6 h, intravenous glucose tolerance test was performed. Lipid infusion elicited an increase (P < 0.05) in the NEFA, beta-hydroxybutyrate, and triglyceride concentrations compared with the baseline value and NS infusion. Infusion of NS did not influence blood glucose concentration; however, LE infusion increased plasma glucose concentration (P < 0.05). At time point 12 h, serum insulin concentrations were increased (P < 0.05) in NS treatment; however, such an increase was not observed in the LE treatment. Insulin sensitivity index for the LE infusion was lower (P < 0.05) than that for the NS treatment. The glucose effectiveness was not (P > 0.05) different among treatments. In the LE treatment, acute-phase insulin responses increased (P < 0.05) and disposition index decreased (P < 0.001) compared with NS treatment. The results showed that experimentally induced NEFA in blood could cause insulin resistance in sheep. The current model could be used to evaluate the pathogenesis of conditions associated with increased lipid mobilization and insulin resistance.

      PubDate: 2015-09-25T13:43:18Z
  • Duration of fasting but not diurnal variation affects the response to
           glucagon in healthy cats
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): C. Gilor, R. Glock, S. Gilor
      The role of glucagon disturbances in diabetes is increasingly recognized. Glucagon stimulation tests (GSTs) have been described in cats previously, but information is lacking on the response of cats to glucagon under specific conditions. The aim of this study was to assess a novel protocol for GST using human-recombinant glucagon and the effect of diurnal variation and duration of fasting using this protocol in healthy cats. All intravenous doses resulted in occasional vomiting and nausea, and eventually, a 20-μg/kg intramuscular dose was chosen. Five healthy cats were then used in a repeated-measures study. Cats were free-fed regularly at 7:30 AM and 5:30 PM for 30 min. In each cat, GST was performed at 7 PM after a 25-h fast (PM25), at 9 AM after a 25-h fast (AM25), and at 9 AM after a 15-h fast (AM15). Glucose and insulin concentrations were measured at −15, 0, 15, 25, 35, 45, and 60 min after stimulation. Baseline and peak concentrations were compared using the Friedman test. Baseline glucose and insulin did not differ significantly between treatment groups. Peak glucose concentrations occurred at 15 min and were significantly higher (P = 0.0085) at AM15 (mean ± standard deviation = 185.2 ± 43.0 mg/dL) vs AM25 (144.4 ± 10.5 mg/dL) and PM25 (128.0 ± 18.4 mg/dL). Similarly, peak insulin concentrations occurred at 15 min and were significantly higher (P = 0.04) at AM15 (1,911 ± 1,153 pg/mL) vs AM25 (739 ± 52 pg/mL) or PM25 (549 ± 366 pg/mL). In conclusion, prolonged fasting significantly blunted the glycemic response to glucagon compared with shorter fasting, but diurnal variation had no significant effect on glucose or insulin responses.

      PubDate: 2015-09-25T13:43:18Z
  • Interleukin-6 inhibits adrenal androgen release from bovine adrenal zona
           reticularis cells by inhibiting the expression of steroidogenic proteins
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): S. McIlmoil, G.B. Call, M. Barney, J. Strickland, A.M. Judd
      Interleukin-6 (IL-6) is secreted by adrenocortical cells and modifies cortisol secretion. In this study, the effects of IL-6 on adrenal androgen release were investigated. The zona reticularis (ZR) was generally isolated from bovine adrenal glands by dissection. In select experiments, the intact adrenal cortex (ie, all 3 adrenocortical zones) was dissected from the adrenal glands. For androgen release experiments, ZR and intact adrenocortical cubes were dispersed into isolated cells, the cells cultured and exposed to IL-6 and/or adrenocorticotropic hormone (ACTH), and androgen release determined by radioimmunoassay. Basal and ACTH-stimulated androgen release from the ZR was inhibited by IL-6 in a concentration-dependent (10–1000 pg/mL) and time-dependent (4–24 h) manner (P < 0.01 by 1-way analysis of variance and the Bonferroni test). In contrast, IL-6 increased basal and ACTH-stimulated androgen release from mixed adrenocortical cells (P < 0.01). The mechanism of IL-6 inhibition of androgen release was investigated by exposing ZR strips to IL-6 and measuring the expression of the messenger RNA (mRNA) and protein of steroidogenic factors. Basal and ACTH-stimulated expression of the mRNA and protein for steroidogenic acute regulatory protein, cholesterol side chain cleavage enzyme, 3-β-hydroxysteroid dehydrogenase type 2, steroid 17-α-hydroxylase/17,20 lyase/17,20 desmolase, and the nuclear factor steroidogenic factor 1 (SF-1), that stimulates steroidogenesis, were decreased by IL-6 (P < 0.01). In contrast IL-6 increased the mRNA and protein for dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1), a nuclear factor that inhibits steroidogenesis (P < 0.01). In summary, IL-6 decreased androgen release and the expression of steroidogenic factors in the ZR, and this decrease may be mediated in part through increasing DAX-1 and decreasing SF-1.

      PubDate: 2015-09-25T13:43:18Z
  • Effects of insulin treatment on the response to oleate and octanoate of
           food intake and fatty acid–sensing systems in rainbow trout
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): M. Librán-Pérez, C. Velasco, C. Otero-Rodiño, M.A. López-Patiño, J.M. Míguez, J.L. Soengas
      We hypothesized that food intake and the response of fatty acid (FA)-sensing systems in hypothalamus, liver, and Brockmann bodies of rainbow trout to raised levels of oleate (OL) or octanoate (OCT) is modified by insulin treatment. To assess this hypothesis, 15 fish per group received intraperitoneally 10-mL/kg injection of saline solution alone (control), or containing insulin (2-mg bovine insulin/kg body mass), OL (300 μg/kg), OCT (300 μg/kg), insulin + OL, or insulin + OCT to be sampled 6 h later to assess parameters related to FA sensing. Our results suggest that the modulatory role of insulin on the responses of hypothalamic FA-sensing systems to changes in circulating levels of OL or OCT was of minor importance in contrast to the mammalian model. However, this is in contrast with the effects observed in another experiment assessing changes in food intake after similar treatments because insulin treatment enhanced the anorectic effects of FA alone, and the effect was especially relevant (P < 0.001) for OCT, in contrast with the mammalian model where this FA is not inducing an anorectic response. In liver and Brockmann bodies, insulin treatment enhanced the responses to OL or OCT treatment in parameters related to FA sensing. Therefore, we provide for the first time in fish, and in a non-mammalian vertebrate, evidence for the modulation of FA-sensing systems by insulin.

      PubDate: 2015-09-25T13:43:18Z
  • Ovarian and hormonal responses to single or continuous peripheral
           administration of senktide, a neurokinin 3 receptor agonist, during the
           follicular phase in goats
    • Abstract: Publication date: October 2015
      Source:Domestic Animal Endocrinology, Volume 53
      Author(s): N. Endo, L.P. Rahayu, Y. Ito, T. Tanaka
      The present study aimed to investigate the effects of single or continuous administration of a neurokinin 3 receptor agonist, senktide, on hormonal and follicular dynamics in follicular phase goats. Goats were injected with PGF2α in the luteal phase and treated with an intravaginal progesterone device for 10 d. At 12 h after the cessation of progesterone treatment, the goats received a single intravenous injection of senktide (200 nmol, n = 4) or vehicle (n = 4), or continuous intravenous infusion of senktide (20 nmol/min, n = 6) or vehicle (n = 6) for 6 h. Blood sampling and ovarian ultrasonography were performed during the experiment. A single injection of senktide did not influence the number of luteinizing hormone (LH) pulses and mean LH concentration. On the other hand, continuous injection of senktide caused a sustained increase in LH secretion, and mean LH concentration in samples collected at 10-min intervals for 6 h after the start of infusion was higher than that of vehicle-treated goats (2.8 ± 1.3 vs 1.0 ± 0.6 ng/mL, P < 0.01). In 4 of 6 goats, LH concentrations reached their peaks during the 6-h senktide infusion, and ovulation was observed at 48 h after the start of infusion without estrous behavior. The remaining 2 senktide-treated goats and all vehicle-treated goats showed estrus and ovulated at 72 or 96 h after treatment. These results suggest that continuous infusion of senktide in follicular phase goats can cause a sustained increase in LH and advance the time of ovulation.

      PubDate: 2015-09-25T13:43:18Z
  • Regulation and localization of vascular endothelial growth factor within
    • Abstract: Publication date: Available online 25 September 2015
      Source:Domestic Animal Endocrinology
      Author(s): M.K. VanKlompenberg, R. Manjarín, C.E. Donovan, J.F. Trott, R.C. Hovey
      The vascular network within the developing mammary gland (MG) grows in concert with the epithelium to prepare for lactation, although the mechanisms coordinating this vascular development are unresolved. Vascular endothelial growth factor A (VEGF-A) mediates angiogenesis and vascular permeability in the MG during pregnancy and lactation, where its expression is upregulated by prolactin. Given our previous finding that late-gestational hyperprolactinemia induced by domperidone (DOM) increased subsequent milk yield from gilts, we sought to establish changes in vascular development during late gestation and lactation in the mammary glands of these pigs as well as determine whether DOM altered MG angiogenesis and the factors regulating it. Gilts received either no treatment (n=6) or DOM (n=6) during late gestation, then had their MG biopsied from late gestation through lactation to assess microvessel density, VEGF-A distribution and mRNA expression, and aquaporin (AQP) gene expression. Microvessel density in the MG was unchanged during gestation then increased between days 2 and 21 of lactation (P < 0.05). The local expression of mRNA for VEGF-A 120 , VEGF-A 147 , VEGF-A 164 , VEGF-A 164 b, VEGF-A 188 , VEGF receptors-1 and -2, and AQP1 and AQP3 all generally increased during the transition from gestation to lactation (P < 0.05). Immunostaining localized VEGF-A to the apical cytoplasm of secretory epithelial cells, consistent with a far greater concentration of VEGF-A in colostrum/milk versus plasma (P < 0.0001). There was no effect of DOM on any of the variables analyzed. In summary, we find that vascular development in the MG increases during lactation in first-parity gilts and that VEGF-A is a part of the mammary secretome. Although late gestational hyperprolactinemia increases milk yield, there was no evidence it altered vascular development.

      PubDate: 2015-09-25T13:43:18Z
  • Intrafollicular expression and potential regulatory role of cocaine- and
           amphetamine-regulated transcript (CART) in the ovine ovary
    • Abstract: Publication date: Available online 16 September 2015
      Source:Domestic Animal Endocrinology
      Author(s): Y. Huang, X.L. Yao, J.Z. Meng, Y. Liu, X.L. Jiang, J.W. Chen, P.F. Li, Y.S. Ren, W.Z. Liu, J.B. Yao, J.K. Folger, G.W. Smith, L.H. Lv
      Follicular growth is regulated by a complex interaction of pituitary gonadotropins with local regulatory molecules. Previous studies demonstrated an important role for cocaine-and amphetamine-regulated transcript (CART) in regulation of granulosa cell estradiol production associated with dominant follicle selection in cattle. However, intra-ovarian expression and actions of CART in other species, including sheep, are not known. The objective of described studies was to investigate expression of CART in sheep follicles and determine effects of CART on indices of ovine granulosa cell function linked to follicular development. Results demonstrated expression of CART mRNA and prominent intra-ovarian localization of CART peptide in granulosa cells of sheep follicles. Granulosa cell CART mRNA was lower, but follicular fluid estradiol concentrations were higher in large (> 5 mm) follicles versus smaller 3-5 mm follicles harvested from sheep ovaries of abattoir origin. CART treatment inhibited FSH-induced estradiol production by cultured ovine granulosal cells and also blocked the FSH-induced increase in granulosa cell numbers. Results demonstrate expression of CART in sheep follicular tissues and suggest potential biological actions of CART which are inhibitory to ovine follicular growth and development.

      PubDate: 2015-09-25T13:43:18Z
  • Insulin: pancreatic secretion and adipocyte regulation
    • Abstract: Publication date: Available online 18 July 2015
      Source:Domestic Animal Endocrinology
      Author(s): L.H. Baumgard, G.J. Hausman, M.V. Sanz Fernandez
      Insulin is the primary acute anabolic coordinator of nutrient partitioning. Hyperglycemia is the main stimulant of insulin secretion, but other nutrients such as specific amino acids, fatty acids, and ketoacids can potentiate pancreatic insulin release. Incretins are intestinal hormones with insulinotropic activity and are secreted in response to food ingestion, thus integrating diet chemical composition with the regulation of insulin release. In addition, prolactin is required for proper islet development, and it stimulates β-cell proliferation. Counterintuitively, bacterial components appear to signal insulin secretion. In vivo lipopolysaccharide infusion acutely increases circulating insulin, which is paradoxical as endotoxemia is a potent catabolic condition. Insulin is a potent anabolic orchestrator of nutrient partitioning, and this is particularly true in adipocytes. Insulin dictates lipid accretion in a dose-dependent manner during preadipocyte development in adipose tissue–derived stromal vascular cell culture. However, in vivo studies focused on insulin's role in regulating adipose tissue metabolism from growing, and market weight pigs are sometimes inconsistent, and this variability appears to be animal, age and depot dependent. Additionally, porcine adipose tissue synthesizes and secretes a number of adipokines (leptin, adiponectin, and so forth) that directly or indirectly influence insulin action. Therefore, because insulin has an enormous impact on agriculturally important phenotypes, it is critical to have a better understanding of how insulin homeostasis is governed.

      PubDate: 2015-09-25T13:43:18Z
  • Pharmacologic analyses of 4 chicken melanocortin-4 receptor mutations
    • Abstract: Publication date: Available online 2 July 2015
      Source:Domestic Animal Endocrinology
      Author(s): Z.-Q. Wang, J.-S. Huang, J.-H. Zhou, S. Lin, X.-F. Jiang, Y.-X. Tao
      The melanocortin-4 receptor (MC4R) is a critical regulator of mammalian food intake and energy expenditure, with receptor activation resulting in decreased food intake and increased energy expenditure. Recently, studies on role of MC4R in regulation of food intake have been extended to other species, such as chicken. Functional study of mutant MC4Rs is important in proving the causal link between MC4R mutation and production traits. Herein, we cloned chicken MC4R (cMC4R) complementary DNA and generated 4 mutant cMC4Rs (Q18H, G21R, S76L, and L299P) by site-directed mutagenesis and measured their expression by flow cytometry. Pharmacologic characteristics were analyzed with binding and signaling assays using 3 agonists. We showed that G21 R had decreased cell surface and total expression (P < 0.05), whereas the other 3 mutants had similar total and cell surface expression levels as wild-type cMC4R. The 4 mutants had either decreased (Q18H, G21R, S76L; P < 0.05) or no (L299P) binding to radiolabeled [Nle4, D-Phe7]-α-melanocyte-stimulating hormone (MSH). In signaling assays, Q18H was constitutively active. Q18H, G21R, and S76L had decreased responses to α-MSH stimulation (P < 0.05). L299P had decreased basal and ligand-stimulated signaling (P < 0.01). Nle4, D-Phe7-MSH was the most potent agonist for cMC4R and therefore would be better suited for further in vivo studies. We conclude that the cloned cMC4R was a functional receptor and provided detailed functional data for these mutations, contributing to a better understanding of cMC4R variants associated with production traits.

      PubDate: 2015-09-25T13:43:18Z
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