Comparative effects of androgens and catecholestrogens on progesterone production by porcine granulosa cells

Abstract

The objective of the present studies was to evaluate and compare the effects of 5α-dihydrotestosterone (DHT) to those of 2-hydroxyestradiol (2-OH-E 2) and 2-methoxyestradiol (2-MeO-E 2) on progesterone production in cultured porcine granulosa cells. Granulosa cells were exposed to various treatments of DHT, 2-OH-E 2 and 2-MeO-E 2 in the absence or presence of follicle stimulating hormone (FSH) for 4 days and concentrations of progesterone hi medium and cell numbers were determined. In the absence of FSH, maximally effective concentrations of DHT (1 μg/ml) and 2-OH-E 2 (4 μg/ml) stimulated progesterone production (ng/10 5 cells/48 h) to 2.2 ± 0.2- and 10.8 ± 2.2-fold of controls ( n = 4 experiments), respectively. In the presence of 200 ng/ml FSH, progesterone production stimulated by 1 μg/ml DHT and 4 μg/ml 2-OH-E 2 was 5.4 ± 1.1- and 15.5 ± 6.0-fold of controls ( n = 4 experiments), respectively. Thus, FSH appeared to enhance the response of both DHT and 2-OH-E 2. The dose-response of DHT was biphasic in the presence and absence of FSH, such that progesterone production in the presence of 8 μg/ml DHT was similar to basal progesterone production. Concurrent treatment with saturating concentrations of 2-OH-E 2 and DHT resulted in fully additive increases in progesterone production. Testosterone mimicked the effect of DHT. In comparison, concurrent treatment of saturating concentrations of 2-MeO-E 2 and DHT or 2-MeO-E 2 and 2-OH-E 2 resulted in progesterone production that was only partially additive. Progesterone production stimulated by DHT alone and 2-OH-E 2 alone was significantly reduced (50% inhibition) with addition of the antiandrogen hydroxyflutamide. Estradiolstimulated progesterone production was unaffected by hydroxyflutamide. Since the maximal effectiveness of 2-OH-E 2 to stimulate progesterone production was 3–5 times greater than that of DHT and the effects of 2-OH-E 2 and DHT (or testosterone) were fully additive, we conclude that the mechanisms of action of androgens and 2-OH-E 2 within porcine granulosa cells are different. In addition, our studies suggest that hydroxyflutamide may exhibit discrete antiandrogenic and anticatecholestrogenic activity.