Effect of ovarian on FSH release and subunit synthesis in rat anterior pituitary cells in culture

Kim, You Kon; Kim, Kyung Hwan

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.