Role of protein kinase C in luteinizing hormone-releasing hormone (LHRH)-stimulated progesterone production in rat granulosa cells

Abstract

Treatment of rat granulosa cells with LHRH or the phorbol ester TPA stimulated progesterone (P) production during a 5-h incubation. The concomitant presence of a potent inhibitor of protein kinase C attenuated the LHRH effect by ca. 60% and completely blocked the stimulatory effect of TPA. Addition of TPA (10 −9, 10 −8 or 10 −7M) or dioctanylglycerol (100 μg/ml) increased P production; these stimulatory effects were not potentiated by the concomitant presence of a calcium ionophore (A23187, 10 −7 or 10 −6M). These data support the hypothesis that protein kinase C activation have a role in the steroidogenic action of LHRH in the ovary.