The P2Y receptors belong to the G-protein coupled receptors superfamily. P2Y receptors mediate the actions of the extracellular nucleotides (ATP, ADP, UTP and UDP) and regulate several physiologic responses, among them, cardiac function, platelet aggregation and SMC proliferation.nThe mammalian P2Y family currently includes eight functional receptors; P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and the UDP-glucose receptor, now renamed P2Y14.nP2Y1 receptor is abundantly expressed in a number of tissues. In platelets, P2Y1 receptor is co-expressed with P2Y12 receptor, responsible for the initial shape change, aggregation, and rise in intracellular Ca2+ upon activation in response to ADP