STEROIDOGENESIS IN VITRO BY HUMAN OVARIAN FOLLICLES DURING THE PROCESS OF ATRESIA

Abstract

Slices of each of the six antral follicles at different stages of atresia isolated from ovaries of six patients with or without pretreatment with HCG before laparotomy, were incubated with [1-14C] acetate. Incorporation into progestins, androgens and oestrogens was assessed by the reverse dilution technique with recrystallization to constant specific activity. The greatest incorporation into androstenedione without any incorporation into progesterone was commonly observed throughout the morphologically defined three stages of atresia. In the first stage atretic follicles, characterized by coexistence of normally developed thecal cells with degenerating granulosa cells, a minute incorporation into oestradiol was identified. In the second state atretic follicles, showing hyperplasia and hypertrophy of thecal cells without granulosa cells, an increased incorporation into androgens was shown. Treatment with HCG induced similar but much pronounced changes in function and morphology. In the third stage atretic follicles, with subsiding thecal cells, a diminished incorporation into androstenedione was observed with 17-hydroxyprogesterone being the only other steroid formed in this stage. The observed qualitative and quantitative changes of steroidogenesis in vitro may be functional reflections of structural changes during the atretic process.

Polycystic ovarian syndrome: a misnomer for an enigmatic disease

“…Androgens induce a multifollicular pattern, increase the number of atretic follicles, promote luteinization of the theca cells and, eventually, lead to hyperthecosis of the ovary21. However, atretic follicles and hyperplastic thecal cells are also a significant source of androgen overproduction in PCOS22, which suggests the endocrinological and histological features of the syndrome are both causative and reactive.…”

EDITORIAL: Immuno‐Endocrinology of Cyclic Ovarian Function

“…The notion that TNF-a may be implied in follicular atresia has been postulated based on the finding that alteration of steroidogenic pattern of explant rat follicles with elevated progesterone and androgen production in response to LH can be reproduced by TNF_a 19 and these changes are known to be characteristic of follicular atresia. 39,72,73 Since it is generally accepted that premature or untimely action of LH on the growing follicle forces it to undergo atresia.I" it is likely that TNF-a mediates atresia-inducing action of LH, though mediating activity by TNF-a of LH action is not tested. In support of this view, TNF-a is shown to inhibit FSH-induced aromatase activity,2o,21,75 or to attenuate the ability of TGF-[3 to enhance estrogen and progesterone production of granulosa cells.i" suggesting that TNF-a has anti-FSH action in terms of FSHinduced cytodifferentiation of these cells.…”