Estradiol-17beta biosynthesis in cultured granulosa cells from hypophysectomized immature rats; stimulation by follicle-stimulating hormone.

Granulosa cells isolated from the ovaries of hypophysectomized immature rats synthesize and secrete estradiol-17beta and estrone when grown for 2 days in monolayer culture in a synthetic medium containing testosterone (0.5 muM) and a highly purified follicle-stimulating hormone (FSH) preparation (0.25 mug/ml). Secretion is negligible in the absence of either testosterone or FSH, and a highly purified luteinizing hormone (LH) preparation (0.25 mug/ml) was without significant stimulatory effect. It is concluded that FSH regulates estrogen biosynthesis in granulosa cells of hypophysectomized rats by a specific stimulation of the aromatizing enzyme system.