The P2Y1 receptor is an ADP receptor antagonized by ATP and expressed in platelets and megakaryoblastic cells

The human P2Y1 purinoceptor has been expressed in Jurkat cells and the effects of HPLC purified nucleotides on calcium movements were measured. The most potent agonist was 2-methylthio-ADP followed by ADP. ATP, Sp-ATPalphaS and beta,gamma-methylene-ATP were competitive antagonists. Suramin and PPADS inhibited the effects of ADP. This pharmacological profile is the same as that of the so-called P2T purinoceptor responsible for platelet aggregation, which has not yet been identified. Using PCR we found the P2Y1 receptor to be present in blood platelets and megakaryoblastic cell lines. These data suggest that the P2Y1 receptor may be the elusive P2T receptor.