Differential actions of FSH and androgens on progesterone catabolism by rat granulosa cells.

Rat granulosa cells were preincubated with follicle-stimulating hormone (FSH, 1 micrograms/ml) and/or androgens (testosterone and 5 alpha-dihydrotestosterone, 0.5 microM) and subsequent [4-14C]progesterone metabolism by these cells was studied. Granulosa cells metabolized radiolabeled progesterone to three major products 20 alpha-hydroxy-4-pregnen-3-one, 3 alpha-hydroxy-5 alpha-pregnan-20-one, and 5 alpha-pregnane-3 alpha, 20 alpha-diol. Androgens, but not FSH, decreased overall progesterone utilization. Both FSH and androgens decreased conversion of progesterone to 20 alpha-hydroxy-4-pregnen-3-one. The accumulation of 5 alpha-pregnane-3 alpha, 20 alpha-diol was increased by FSH, decreased by testosterone, and not altered by 5 alpha-dihydrotestosterone. The accumulation of 3 alpha-hydroxy-5 alpha-pregnan-20-one was significantly increased by both FSH and androgens. Present results indicate that FSH as well as androgens modulate progesterone metabolism by rat granulosa cells. FSH appears to increase 5 alpha-reductase activity and/or decrease 20 alpha-hydroxysteroid dehydrogenase activity while androgens decrease only 20 alpha-hydroxysteroid dehydrogenase activity.