Lysophosphatidylcholine in oxidized low-density lipoprotein increases endothelial susceptibility to polymorphonuclear leukocyte-induced endothelial dysfunction in porcine coronary arteries. Role of protein kinase C.

Abstract

We have shown that transferred lysophosphatidylcholine (lysoPC) from oxidized low-density lipoprotein (Ox-LDL) to endothelial surface membrane activates protein kinase C (PKC) in endothelial cells, suggesting that Ox-LDL could alter endothelial functions through PKC activation. The purposes of the present study were to examine whether the endothelial susceptibility to polymorphonuclear leukocytes (PMNs) may be altered in Ox-LDL-treated coronary arteries, which have properties closely resembling those observed in atherosclerotic arteries, and to determine the mechanism(s) by which Ox-LDL may affect the endothelial susceptibility to PMNs. Isolated porcine coronary arteries were cannulated and perfused with oxygenated culture medium with or without LDLs or lipids at a constant flow (37 degrees C, pH 7.4). The treatment of porcine coronary arteries with Ox-LDL increased endothelial adhesiveness to PMNs and augmented PMN-induced impairment of endothelium-dependent arterial relaxation (EDR). Furthermore, Ox-LDL...