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Inhibitory Regulation of Inhibin Gene Expression by Thyroid Hormone during Ovarian Development in Immature Rats

https://doi.org/10.1006/bbrc.1997.7919Get rights and content

Abstract

To explore the role of the thyroid gland in ovarian development during the initiation process of puberty, we examined the effects of hypothyroidism on the secretion of ovarian hormones during equine chorionic gonadotropin (eCG)-induced follicle development in immature female rats. Immature rats at 22 days of age were thyroidectomized (Tx) to cause hypothyroidism and then given a single s.c. injection of 5 IU eCG at 26 days of age to induce normal first ovulation. The blood samples were collected at 0, 24, and 48 h after eCG treatment to measure inhibin and estradiol by radioimmunoassay. Serum inhibin and estradiol levels in eCG-primed Tx animals were significantly higher at 24 and 48 h after eCG treatment than those in controls (eCG treated non-Tx rats). The number of healthy follicles larger than 400 μm in diameter and ovarian weight were significantly increased in Tx rats at 48 h after eCG treatment, compared to those in controls. The number of oocytes which are ovulated by an injection of human chorionic gonadotropin (10 IU) was significantly increased on the day after eCG treatment, compared to that of eCG treated non-Tx rats. The increments in both hormones levels, the number of large antral follicles, and ovarian weight in eCG-primed Tx animals were suppressed up to control levels with daily administrations of 5.0 μg thyroxine (T4) for 6 days during 22 to 27 days of age. The expression of mRNAs for inhibin α and βAsubunits increased in eCG-primed Tx rats at 48 hr after eCG treatment, and the increase in inhibin mRNAs was suppressed by T4treatment up to control levels. These results clearly demonstrate that thyroid hormone takes part in an inhibitory regulation of ovarian hormonal secretion and folliculogenesis in eCG-primed immature female rats.

References (37)

  • N.G. Wakim et al.

    Am. J. Obstet. Gynecol.

    (1987)
  • P. Chomczynski et al.

    Anal. Biochem.

    (1987)
  • M. DeVisscher et al.

    The Thyroid Gland

    (1980)
  • C. Longcope
  • J.F. Bruni et al.

    Endocrinol.

    (1975)
  • P.R. Krohn

    J. Endocrinol.

    (1951)
  • T. Maruo et al.

    Endocrinol.

    (1987)
  • E. Ortega et al.

    Life Sci.

    (1989)
  • T. Maruo et al.

    Acta Endocrinol.

    (1992)
  • A.N. Wakin et al.

    Fertil. Steril.

    (1993)
  • J.A.M. Mattheij et al.

    J. Endocrinol.

    (1995)
  • P.S. Cooke et al.

    Endocrinol.

    (1991)
  • P.S. Cooke et al.

    Endocrinol.

    (1991)
  • L.A. Van Haaster et al.

    Endocrinol.

    (1992)
  • E.A. Janini et al.

    Endocrine Rev.

    (1995)
  • L.H. Van Haaster et al.

    Endocrinol.

    (1993)
  • T.K. Woodruff et al.

    Mol. Endocrinol.

    (1987)
  • F.H. De Jong

    Physiol. Rev.

    (1988)
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      In this comparative review, we provide further evidence for direct crosstalk between the androgen and TH axes throughout male reproductive development, weakening the proposal that the female reproductive axis solely mediates TH effects. TH regulation has been implicated in the reproductive development of many different vertebrate species (rainbow trout, Oncorhynchus mykiss (Holloway et al., 1999); zebrafish, Danio rerio (Filby et al., 2007); African clawed frog, Xenopus laevis (Goleman et al., 2002); Western clawed frog, Silurana tropicalis (Duarte-Guterman et al., 2010; Duarte-Guterman and Trudeau, 2011; Langlois et al., 2010a, 2011); Bocage’s Wall Lizard, Podarcis bocagei (Bicho et al., 2013); Indian garden lizard, Calotes versicolor (Haldarmisra and Thapliyal, 1981); American tree sparrows, Spizella arborea (Reinert and Wilson, 1996); Indian finch, Lal munia, Estrilda amandava (Thapliyal and Pandha, 1967); red munia, E. amandava (Saxena et al., 2011); sheep, Ovis aries (Karch et al., 1995); rat, Rattus norvegicus (Tamura et al., 1998)). This cross regulation has been studied extensively on the physiological level, with many studies examining the role of the TH axis in testes function and development (X. laevis (Goleman et al., 2002); Hokkaido salamander, Hynobius retardatus (Kanki and Wakahara, 1999); P. bocagei (Bicho et al., 2013); C. versicolor (Haldarmisra and Thapliyal, 1981); Lonchura punctulata (Gupta and Thapliyal, 1984), E. amandava (Saxena et al., 2011; Thapliyal and Pandha, 1967); Chicken, Gallus gallus (Akhlaghi and Zamiri, 2007); O. aries (Parkinson et al., 1995); R. norvegicus (Anbalagan et al., 2010; Cristovao et al., 2002; Holsberger and Cooke, 2005; Jannini et al., 1995; Lagu et al., 2005; Marchlewska et al., 2011; Wagner et al., 2008, 2009; Wajner et al., 2009); Homo sapiens (Maran, 2003)).

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    DeVisscher, M.

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