PHOSPHOLIPASE A(2) - ITS ROLE IN ADP-INDUCED AND THROMBIN-INDUCED PLATELET ACTIVATION MECHANISMS

ADP and thrombin are two of the most important agonists of platelet ag gregation - a cellular response that is critical for maintaining norma l hemostasis. However, aberrant platelet aggregation induced by these agonists plays a central role in the pathogenesis of cardiovascular an d cerebrovascular diseases. Agonist-induced primary or secondary activ ation of phospholipases leads to generation of the second messengers t hat participate in biochemical reactions essential to a number of plat elet responses elicited by ADP and thrombin. Phospholipase A(2) (PLA(2 )) has been linked to cardiovascular diseases. However, the mechanism( s) of activation of PLA(2) in platelets stimulated by ADP and thrombin has remained less well defined and much less appreciated. The purpose of this review is to examine and compare the molecular mechanisms of activation of PLA(2) in platelets stimulated by ADP and thrombin. (C) 1998 Elsevier Science Ltd. All rights reserved.