Dependence of thymocyte apoptosis on protein kinase C and phospholipase A2

Abstract
The effect of inhibitors and activators of protein kinase C and phospholipase A2 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 A2 prevents apoptosis induced by all the factors. The results obtained indicate that both protein kinase C and phospholipase A2 are involved in the thymocyte apoptosis.