Effect of luteinizing hormone-releasing hormone on rat adrenocortical cells

The effects of luteinizing hormone-releasing hormone (LH-RH) on the function of rat adrenal cortex were investigated by using dispersed zona glomerulosa (capsular) and zona fasciculata-reticularis (inner) cells. LH-RH increased basal (but not adrenocorticotropic hormone (ACTH)-stimulated) corticosterone secretion of inner cells, without affecting either aldosterone or corticosterone production by capsular cells. LH-RH markedly raised basal (but not ACTH-enhanced) cyclic-AMP release by inner cells. The corticosterone secretagogue action of LH-RH was abolished by the protein kinase A inhibitor H-89. The conclusion is drawn that LH-RH specifically stimulates adrenal glucocorticoid secretion in rats through the activation of the adenylate cyclase signaling pathway.