Profiles of Circulating Steroid Hormones, Gonadotropins, Immunoreactive Inhibin and Prolactin During Pregnancy in Goats and Immunolocalization of Inhibin Subunits, Steroidogenic Enzymes and Prolactin in the Corpus Luteum and Placenta

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Author(s)

    • Watanabe Gen WATANABE Gen
    • Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology
    • LI Jun Y.
    • Animal Resource Science Center, Graduated School of Agriculture and Life Science, University of Tokyo
    • MANABE Noboru
    • Animal Resource Science Center, Graduated School of Agriculture and Life Science, University of Tokyo
    • TAYA Kazuyoshi
    • Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology

Abstract

The current study was performed to follow up the circulating hormonal changes and to correlate the findings with the physiological activity of the corpus luteum (CL) and placenta during pregnancy in goats. Blood samples were collected weekly from five goats during pregnancy for measuring steroid and protein hormones. A gradual increase was observed in immunoreactive (ir-) inhibin, with maximal levels at the 17th week. The plasma concentrations of estradiol and prolactin (PRL) showed nearly similar patterns during pregnancy, where they declined to basal levels during the first 4 weeks post-breeding and then increased significantly, with the maximal concentration during late pregnancy. The plasma FSH and LH concentrations were maintained at basal levels throughout the gestation period. The plasma progesterone concentration abruptly increased in the first week post-breeding and remained at high values throughout the pregnancy period. Immunohistochemical localization of inhibin alpha, beta<sub>A</sub>, beta<sub>B</sub> and steroidogenic enzymes cytochrome P450 aromatase, 3alpha-hydroxysteroid dehydrogenase (3betaHSD), cytochrome 17alpha-hydroxylase P450 and cholesterol side-chain cleavage cytochrome P450 in the cyclic and pregnant goat CL revealed positive immunoreactivity without affinity differences between the luteal and pregnancy stages. The placental syncytiotrophoblasts also showed positive staining, except for inhibin beta<sub>A</sub> and 3betaHSD. The giant binucleate cells of the placenta showed positive immunoreactions to PRL. These results suggest that the high concentrations of ir-inhibin, estradiol and PRL during late pregnancy are of placental origin and that the placenta may have a vital role in the maintenance of pregnancy, regulation of mammary growth and preparation for kidding and lactation in goats.<br>

Journal

  • Journal of Reproduction and Development

    Journal of Reproduction and Development 56(2), 243-250, 2010-04-01

    THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT

References:  57

Cited by:  2

Codes

  • NII Article ID (NAID)
    10026324516
  • NII NACSIS-CAT ID (NCID)
    AA10936678
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    09168818
  • NDL Article ID
    10656536
  • NDL Source Classification
    ZR22(科学技術--農林水産--畜産)
  • NDL Call No.
    Z54-H305
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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