Modulation of Progesterone Secretion by Androgens in Porcine Granulosa Cell Cultures

Abstract

The influence of testosterone, androstenedione and dihydrotestosterone (DHT) on the progesterone (P₄) production by cultured porcine granulosa cells was studied in the presence or absence of gonadotropins. Porcine granulosa cells from large follicles (6-12 mm in diameter) were incubated for 2 days with 5% CO₂ in air with testosterone, androstenedione and DHT (10^-12, 10^-10, 10^-8 and 10^-6 M) in the presence or absence of luteinizing hormone (LH, 10 ng/ml) or follicle-stimulating hormone (FSH, 30 ng/ml). P₄ and pregnenolone (P₅) in conditioned culture media were quantified by their specific RIAs. In the absence of gonadotropins, P₄ in media with androgens were not significantly different from controls. In the presence of LH, the addition of testosterone (10^-10, 10^-8 M), androstenedione (10^-8 M) and DHT (10^-8 M) caused a significant 1.3- to 2.3-fold increase in P₄ over that caused by LH alone. In contrast, in the presence of FSH, testosterone (10^-12,10^-10 M), androstenedione (10^-12-10^-6 M) and DHT (10^-6 M) reduced the levels of P₄ by 22% to 41%. The addition of androgens with LH caused a significant increase in P₅, while P₅ decreased in the presence of FSH. P₄/P₅ ratios remained unchanged in the presence of both LH and FSH. These data suggest that the P₄ production by cultured porcine granulosa cells is modulated in a paracrine or an autocrine fashion by androgens in the presence of gonadotropins, and that androgens may exert their actions partly by altering the activity of cholesterol side chain cleavage enzymes.