Structural differences in the ability of lysophospholipids to inhibit endothelium-dependent hyperpolarization by...

The effects of different lysophospholipids on endothelium-dependent hyperpolarization by acetylcholine were examined in rat mesenteric arteries. Lysophosphatidylcholine with 14 or longer carbon acyl chain significantly inhibited the hyperpolarization, while that with 12 or lesser carbon acyl chain was without effect. Lysophosphatidylcholine with unsaturated acyl chain also showed a potent inhibition. Lysophosphatidylinositol and lyso-platelet activating factor, but not phosphatidylcholine, lysophosphatidic acid, lysophosphatidylethanolamine or lysophosphatidylserine, suppressed the hyperpolarization. These results suggest that the length of the carbon acyl chain and the size of the polar head group may be crucial for the effects of lysophospholipids on endothelium-dependent hyperpolarization. Accumulation of these lysophospholipids may play an important role in endothelial dysfunction associated with atherosclerosis.