DEPENDENCE OF THYMOCYTE APOPTOSIS ON PROTEIN-KINASE-C AND PHOSPHOLIPASE A(2)

The effect of inhibitors and activators of protein kinase C and phospholipase A(2) on radiation-induced apoptosis of rat and mouse thymocytes has been studied. It is shown that the apoptosis is prevented by the protein kinase C inhibitor 1-(5-isoquinolinylsulfonyl)-2-methylpiperasine dihydrochloride and is potentiated by protein kinase C activator phorbol 12-myristate 13-acetate, calcium ionophore A23187 and concanavalin A. The protein kinase C activators initiate apoptosis in mouse but not in rat thymocytes. The inhibitor of phospholipase A(2) prevents apoptosis induced by all the factors. The results obtained indicate that both protein kinase C and phospholipase A(2) are involved in the thymocyte apoptosis.