Estrogens augment the stimulation of ovarian aromatase activity by follicle-stimulating hormone in cultured rat granulosa cells.

摘要: The effects of estrogens on ovarian aromatase activity were investigated in vitro using granulosa cells from immature hypophysectomized estrogen-primed rats. cultured for 3 days an androgen-free medium the presence follicle-stimulating hormone (FSH), with or without specified estrogen. After washing, reincubated 5 h 10(-7) M androstenedione, and formation was measured. Estrogen production by control diethylstilbestrol-treated negligible, while FSH stimulated activity. Furthermore, concomitant treatment diethylstilbestrol led to dose-dependent increases FSH-induced ED50 value 4 X 10(-9) apparent Vmax 12- 16-fold higher than those induced alone. direct stimulatory effect time-dependent not accounted cell protein. Various native synthetic also augmented induction aromatases (native estrogens: estradiol-17 beta = estrone greater alpha estriol; hexestrol moxestrol ethinyl estradiol much chlorotrianisene mestranol). 9 M, which is within physiological levels follicular beta. Although androgens enhanced aromatases, a progestin (R5020) mineralocorticoid (aldosterone) effect. Thus, directly augment stimulation FSH. Follicular may activate intraovarian autoregulatory positive feedback mechanisms enhance their own production, resulting selective follicle maturation preovulatory estrogen surge.