Effects of lysophosphatidylcholine and palmitylcarnitine--lipid metabolites produced in ischemia--on porcine coronary and rabbit femoral arteries.

In organ bath experiments, amphiphilic lipids lysophosphatidylcholine (LPC) and palmitylcarnitine (PLC) produced a small increase in tension of nonprecontracted strips of porcine coronary artery with a subsequent decrease to initial level after high concentrations of the agents, both in intact and endothelium-denuded preparations. Both amphiphiles produced dose-dependent but incomplete relaxation of intact coronary strips precontracted with high potassium. The effect of PLC was more pronounced. LPC, 3.10(-6) mol.l-1, did not influence Ca++-dose-response relationships, while PLC in concentration of 10(-5) mol.l-1 abolished the decline in the second Ca++-dose-response curve. Neither PLC nor LPC in concentrations of 3.10(-6) mol.l-1 influenced endothelium-dependent relaxation produced by bradykinin precontracted with high potassium porcine coronary artery. Both amphiphiles did not change tension of nonprecontracted and precontracted with phenylephrine, 10(-6) mol.l-1, rabbit femoral artery ring segments or Ca++-dose-response relationships with and without endothelium.