The P2Y receptors belong to the G-protein coupled receptors superfamily.They mediate the actions of the extracellular nucleotides (ATP, ADP, UTP and UDP). Eight functional mammalian P2Y receptors have been described: P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, P2Y12, P2Y13, and the UDP-glucose receptor, now renamed P2Y14.The human P2Y11 receptor is unique among the P2Y receptors since it is dually coupled to phospholipase C and adenylyl cyclase. P2Y11 receptor is highly pressed in spleen and for much lower extent at platelets.nExpression of P2Y11 receptor was also shown in endothelial cells.6 In granulocytes HL-60), P2Y11 receptor is thought to have a role in granulocytic differentiation