Effect of ovarian on FSH release and subunit synthesis in rat anterior pituitary cells in culture. |
You Kon Kim, Kyung Hwan Kim |
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Abstract |
OBJECTIVE to determine whether ovarian steroids directly regulate FSH release and B subunit synthesis at the pituitary level METHODS: In vitro study. After applying ovarian steroids in cultured rat anterior pituitary cells, we evaluate the amount of relesed FSH and FSH B subunit using dot-blot hybridization. RESULTS: Estradiol alone or GnRH-induced did not modulate FSH release and B ubunit synthesis. Although progesterone alone did not alter FSH release, GnRH-induced FSH release was significantly augmented by the treatment of progesterone. Progesterone alone stimulated FSH B mRNA level. Significant increase in FSH B mRNA level was also observed by the combined treatment of progesterone and GnRH. The effects of progesterone on GnRH-induced FSH release was significantly reduced by the treatment of progesterone antagonist, RU 486. The treatment with progesterone antagonist, RU 486 also abolished progesterone-induced FSH B subunit mRNA biosynthesis. CONCLUSION: From these results, it is, therefore, concluded that estradiol does not seem to be a major regulator for FSH synthesis but progesterone may exert its action at the pituitary level for the synthesis and release of FSH. |
Key Words:
GnRH, Estrogen, Progesterone, FSH, RU486 |
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