Steroid and adenosine 3',5'-monophosphate formation in granulosa and thecal cells from human preovulatory follicles in response to human chorionic gonadotropin.

Abstract

Granulosa and thecal cells from the preovulatory follicles of 14 women were mechanically isolated and separately incubated for short term periods (0.5-4 h) in the presence and absence of hCG. After incubation, tissue cAMP levels and medium progesterone content of (P), androstenedione (A), and 17 beta-estradiol (E2) were determined. All follicles appeared healthy and mature, as judged by their number of granulosa cells, histological examination of the oocytes, athe steroid levels in antral fluid, as well as the appearance of the oocyte-cumulus complexes. Under basal conditions, both granulosa and thecal cells had the capacity to synthesize all of the steroids measured. The predominant steroid formed by the granulosa cells was P, while the thecal cells formed A as the major steroid. Both cell types produced considerable amounts of E2. The addition of hCG in various concentrations gave rise to concentration-dependent increase in cAMP formation in both cell types. Furthermore, hCG caused a statistically significant increase in the formation of P and A by the thecal cells, while steroid formation by the granulosa cells was not significantly altered. With higher concentrations of hCG, however, there was a tendency toward a stimulation of P synthesis in the granulosa cells from most of the follicles tested. It is concluded that in preovulatory follicles of human origin, follicular steroidogenesis is not rigidly compartmentalized between the two cell types. Furthermore, both granulosa and thecal cells are sensitive to stimulation with hCG in this type of follicle.