Effect of atrial, natriuretic peptide on steroidogenesis and on DNA polymerase alpha activity in cultured rat ovarian granulosa cells

摘要

To examine the effects of ANP on steroidogenesis and on DNA polymerase a activity in the ovary, granulosa cells from PMSG-treated immature rats were cultured in the absence or presence of 100 ng/ml ovine LH with various doses of ANP (10, 100, and 1,000 ng/ml) for 24 or 48 h. At the end of the incubation period, the incubation media were collected and progesterone and GAMP levels were measured. Increasing concentrations of ANP alone did not significantly affect the production of progesterone and accumulation of cAMP. However, LH-induced enhancement of progesterone and cAMP was significantly decreased with increasing concentrations of ANP in culture medium after 24 and 48 h (P<0.01 and 0.01, respectively, ANOVA). ANP also inhibited LH-stimulated DNA polymerase a activity in granulosa cells cultured for 48 h in a dose-dependent manner (P<0.05, ANOVA), whereas it did not affect the polymerase activity in the basal state. On the other hand, ANP did not significantly affect the production of estradiol-17 beta in the basal and LH-stimulated states. The results suggest that ANP inhibits the effect of LH on ovarian function, and that ANP is involved in events related to the development of ovarian follicles.