LHRH stimulates plasminogen activator and inhibits steroid production by granulosa cells of adult rat Graafian follicles.

We studied the effects of LHRH and its analogs on plasminogen activator production and progesterone and estradiol secretion by granulosa cells isolated from adult rat Graafian follicles. LHRH and its agonist ([des- -Gly10,D-Trp6,Pro9-NHEt]LHRH) stimulated small but significant increases in plasminogen activator production. This stimulatory action of LHRH was blocked by the addition of the specific antagonist ([D- pGlu1,D-Phe2,D-Trp3,6]LHRH). In contrast, LHRH treatment had no significant effect on basal steroid production by granulosa cells of Graafian follicles cultured for 2-6 days. However, LHRH decreased the FSH-stimulated steroidogenesis. This inhibitory effect of LHRH on steroidogenesis was abolished by concomitant addition of the LHRH antagonist. The results show that LHRH has a stimulatory effect on plasminogen activator production and a suppressive action on steroidogenesis in granulosa cells isolated from Graafian follicles of adult rats.