Role of P2Y1 purinoceptor in ADP-induced platelet activation.

ADP acts as an agonist of platelet aggregation via specific receptors which are still to be characterised. Amplification by PCR of a human platelet cDNA library confirmed the presence of mRNA of the P2Y1 receptor in platelets. In order to determine if these P2Y1 receptors were involved in ADP-induced platelet activation, we determined the effects of A3P5PS, an antagonist of the P2Y1 receptor, on the binding of [33P]2-MeS-ADP, a potent analogue of ADP.

Characterization of P2x1 purinoreceptors on rat platelets: effect of clopidogrel.

This study aimed to determine the binding characteristics of [3H]alpha,beta-Me-ATP, a specific ligand of the P2x1 receptors to rat platelets, and to investigate the effect of clopidogrel, a thienopyridine compound which has been found to selectively inhibit ADP-induced platelet aggregation and adenylyl cyclase ex vivo. Binding of [3H]alpha,beta-Me-ATP to rat platelets was time-dependent and saturable. Scatchard analysis of the saturation binding data indicated that [3H]alpha,beta-Me-ATP bound to one population of specific binding sites with high affinity (KD = 23.