Steroid Hormone Formation in Human Ovarian Follicles in Vitro

Abstract

Ovarian follicles of 5-15 mm in diameter were isolated from 45 ovaries of 34 patients in the follicular and luteal phases of the cycle. Three experiments were done. In the first, follicles were minced and incubated in Krebs-Ringer bicarbonate buffer containing 1-2 .mu.Ci of 4-14C-testosterone in the presence or absence of 100 IU human chorionic gonadotropin (hCG). In the second, minced follicles were incubated with 100 .mu.Ci of sodium acetate 1-14C-under identical conditions. In the third, 10 follicles from a single patient in the late proliferative stage of endometrial dating were cut in halves and incubated with 100 .mu.Ci of 1-14C-acetate under identical conditions. The minced follicle preparation was capable of aromatizing 4-14C-testosterone into radioactive estrone and estradiol in significant amounts. Incorporation of radioactive acetate into pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone, estradiol and estrone was assessed by reversed dilution analysis with recrystallization to constant specific activity. The major radioactive products formed were androstenedione and 17-hydroxyprogesterone in the latter 2 experiments. Dehydroepiandrosterone was 1 of the major steroids in the 2nd experiment. The minor products were testosterone, progesterone and pregnenolone. Smaller but definite incorporations of radioactive acetate into estradiol and estrone occurred in the 2nd experiment. On histological examination, the follicles were characterized by atretic changes. This distribution pattern of radioactive acetate among the steroids probably represents the steroidogenic profile of unstimulated or atretic follicles.