Purinergic receptor distribution in endothelial cells in blood vessels: a basis for selection of coronary artery grafts

Expression levels of the purinergic P2X receptor subunits (P2X 1 to P2X 7) and P2Y 2 were examined in the endothelial cell layer of internal mammary artery (Ann. Thorac. Surg. 54 (1992) 652), radial artery (Ann. Thorac. Surg. 16 (1973) 111) and saphenous vein (Ann. Thorac. Surg. 20 (1975) 628) samples obtained at surgery for coronary artery bypass grafts using immunohistochemistry and confocal microscopy. Similar levels of P2X 1, P2X 2, P2X 3, P2X 7 and P2Y 2 were found in the endothelial cells in all vessels examined while the levels of P2X 5 and P2X 6 were uniformly lower. A clear difference was measured in P2X 4 expression between arteries and veins. Both radial and internal mammary arteries exhibited very low levels of P2X 4 whereas the level in the saphenous vein was 14.6 fold higher ( P