Androgens augment vasoactive intestinal peptide- and growth hormone-releasing hormone-stimulated progestin production by rat granulosa cells

Vasoactive intestinal peptide (VIP) has been shown to stimulate steroid production by cultured rat granulosa cells independently of FSH. In the present study, we have examined the modulatory effects of various steroids on this response. Rat granulosa cells cultured for 2 days with only VIP showed small but significant increases in progesterone and 20 alpha-dihydroprogesterone (20 alpha-OH-P) production. Concomitant treatment with either a synthetic estrogen (diethylstilbestrol), a synthetic progestin (R5020), or cortisol did not augment VIP-stimulated progesterone production; however, the latter two steroids slightly, but significantly, augmented VIP-stimulated 20 alpha-OH-P production. In contrast, concomitant treatment with a synthetic androgen (R1881) dramatically augmented both VIP-stimulated progesterone and 20 alpha-OH-P production. These effects were dose dependent for both VIP and R1881 and could be blocked by the androgen antagonist cyproterone acetate. Time course studies revealed that progester...