R5020 enhances PGE2 stimulated steroidogenesis in cultured rat granulosa cells

Abstract

Progesterone biosynthesis and metabolization to 20alpha-hydroxyprogesterone was stimulated in granulosa cells cultured in the presence of 20 ng/ml of follicle stimulating hormone (FSH) or increasing concentrations of PGE2 (10(-9)-10(-7) M). Concurrent treatment with the synthetic progestin R5020 (10(-6) M) enhanced the FSH or PGE2 stimulated progesterone and 20alpha-hydroxyprogesterone accumulation in culture media, as well as DELTA5-3beta-hydroxysteroid dehydrogenase activity in granulosa cell homogenates. These findings may represent another example of an autocrine control mechanism in which the steroidogenic product of the granulosa cell exerts an ultra-short loop regulation of its own production.