Progesterone stimulates GnRH gene expression in the hypothalamus of ovariectomized, estrogen treated adult rats.
Gonadotropin-releasing hormone (GnRH) is a major neural signal for hypothalamic control of gonadotropin secretion which in turn influences gonadal steroid synthesis. Progesterone (P) is known to affect release and content of GnRH. The action mechanism of P on GnRH mRNA level remains, however, to be resolved. Here we report that P augments GnRH mRNA level in hypothalamic tissues derived from ovariectomized, estradiol-treated adult rats. The stimulatory action of P was time-dependent and lasted at least for 9 h. When RU486, a P receptor antagonist, was administered 1 hr before P treatment, it clearly blocked the stimulatory action of P on GnRH mRNA level. These results strongly suggest that P regulates GnRH gene expression in the rat hypothalamus, presumably through the P receptor-mediated mechanism.
Department of Molecular Biology and SRC for Cell Differentiation, College of Natural Sciences, Seoul National University, South Korea.
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Cho
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Seong
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Cho
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Kim
D000818:Animals; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D015735:Mifepristone / Q000494:pharmacology; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011980:Receptors, Progesterone / Q000037:antagonists & inhibitors; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D013268:Stimulation, Chemical
D004967:Estrogens; D012333:RNA, Messenger; D011980:Receptors, Progesterone; D015735:Mifepristone; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D015719:Single-Strand Specific DNA and RNA Endonucleases