Distribution of P2Y receptor subtypes on haematopoietic cells

1 RT-PCR-southern hybridization analyses with radiolabelled P2Y receptor cDNAs as probes indicated that the peripheral blood leukocytes and the human umbilical vein endothelial cells express P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptors. 2 Of the haematopoietic cell lines tested, promonocytic U937 cells express P2Y(2) and P2Y(6), but not P2Y(1) or P2Y(4); promyelocytic HL-60 cells express the P2Y(1), P2Y(2) and P2Y(6) receptors but not the P2Y(4) receptor; K562 cells express P2Y(1) but not P2Y(2), P2Y(4) or P2Y(6); and Dami cells express P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptors. 3 Of the peripheral blood leukocytes tested, polymorphonuclear cells express P2Y(4) and P2Y(6) but not P2Y(1) or P2Y(2) receptors; monocytes express P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptors and lymphocytes express P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptors. 4 These results suggest a physiological role for different P2Y receptor subtypes in the extracellular nucleotide-mediated stimulation of monocytes, neutrophils, lymphocytes and endothelial cells.