THE ACTION OF FOLLICLE STIMULATING HORMONE AND OF HUMAN CHORIONIC GONADOTROPHIN UPON STEROID SYNTHESIS BY RABBIT OVARIAN TISSUES IN VITRO

Abstract

Rabbit ovarian follicles have been incubated with sodium acetate-C14 with and without the presence of gonadotrophin. The major radioactive metabolites found were dehydroepiandrosterone (DHEA), androst-5-ene-3[beta],17[beta]-diol, testosterone, and 17[alpha]-estradiol. Lesser amounts of radioactivity were found in pregnenolone, progesterone, androstenedione, and estrone. The results are interpreted as evidence that 2 metabolic pathways exist in the follicle; the major one giving rise to androgens and estrogens from [DELTA]5-3[beta]-hydroxysteroids while the other pathway involves pregen-olone and progesterone as intermediates. Follicle stimulating hormone (FSH) and human chorionic gonadotrophin (HCG) both increased the incorporation of acetate-C14 into steroids and decreased the specific activity of cholesterol. The site of action of the gonadotrophins in the metabolic sequence is discussed.