Stimulation of phospholipid synthesis by luteinizing hormone in isolated rat granulosa cells

This report describes the effect of LH on phospholipid metabolism in rat granulosa cells isolated from mature Graafian follicles. As indicated by the incorporation of radioactive phosphate, LH specifically stimulated the labeling of phosphatidic acid (PA) and phosphatidylinositol (PI). This effect was observed after 2 min and was more pronounced with further incubation with LH. Increases in PI labeling were correlated with increases in LH-induced progesterone accumulation. LH also increased the tissue concentrations of PI. Addition of exogenous PA or PI, but not other phospholipids, increased progesterone accumulation by granulosa cells. These results indicate that LH has selective effects on phospholipid metabolism in rat granulosa cells which may play a role in ovarian steroidogenesis.