DISTRIBUTION OF P2Y RECEPTOR SUBTYPES ON HEMATOPOIETIC-CELLS

1 RT-PCR-southern hybridization analyses with radiolabelled P2Y recept or 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, p romonocytic U937 cells express P2Y(2) and P2Y(6), but not P2Y(1) or P2 Y(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 n ot P2Y(2), P2Y(4) or P2Y(6); and Dami cells express P2Y(1), P2Y(2), P2 Y(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) re ceptors. 4 These results suggest a physiological role for different P2 Y receptor subtypes in the extracellular nucleotide-mediated stimulati on of monocytes, neutrophils, lymphocytes and endothelial cells.