Epidermal growth factor antagonizes ovarian theca-interstitial cytodifferentiation.

This study was aimed at testing the hypothesis that epidermal growth factor (EGF) can modulate the gonadotropin-dependent differentiation of theca-interstitial cells in vitro. Addition of EGF to chemically defined culture medium severely antagonized the ability of hCG to transform undifferentiated theca-interstitial cells into active androgen-producing cells. The inhibitory action of EGF was dose-dependent, hormone-specific, and independent of granulosa cells. Since ovarian androgens are obligatory precursors to estrogen formation and induce atresia, a repressive action of EGF on theca-interstitial cytodifferentiation has new implications for understanding the way in which follicles develop in the ovary.