REGULATION OF PLATELET FUNCTIONS BY P2 RECEPTORS

The main role of blood platelets is to ensure primary hemostasis, which is the maintenance of vessel integrity and cessation of bleeding upon injury. While playing a major part in acute arterial thrombosis, platelets are also involved in inflammation, atherosclerosis, and angiogenesis. ADP and ATP play a crucial role in platelet activation, and their receptors are potential targets for antithrombotic drugs. The ATP-gated cation channel P2X1 and the two G protein–coupled ADP receptors, P2Y1 and P2Y12, selectively contribute to platelet aggregation and formation of a thrombus. Owing to its central role in the growth and stabilization of a thrombus, the P2Y12 receptor is an established target of antithrombotic drugs such as clopidogrel. Studies in P2Y1 and P2X1 knockout mice and selective P2Y1 and P2X1 antagonists have shown that these receptors are also attractive targets for new antithrombotic compounds. The potential role of platelet P2 receptors in the involvement of platelets in inflammatory processes is also discussed.