Effects of 5‘-Phosphate Derivatives of 2-Hexynyl Adenosine and 2-Phenylethynyl Adenosine on Responses of Human Platelets Mediated by P2Y Receptors

Newly synthesized mono-, di-, and triphosphate of 2-alkynyl adenosines showed very different behavior in human platelet P2Y receptor models, according to the different alkynyl chains. In fact, 2-hexynyladenosine di- (<BO>5</BO>) and triphosphate (<BO>7</BO>) induced platelet shape change and aggregation and inhibited PGE<INF>1</INF>-induced increase in platelet cyclic AMP. On the contrary, the corresponding 2-phenylethynyladenosine di- (<BO>6</BO>) and triphosphate (<BO>8</BO>) did not induce platelet shape change or aggregation, but inhibited platelet aggregation induced by ADP.