THE PRODUCTION OF NITRIC-OXIDE IN ENDOTHELIAL-CELLS BY AMPHIPHILES

Lysophosphatidylcholine, an endogenous detergent is an endothelium-dep endent smooth muscle relaxant, which acts through the release of nitri c oxide. It is known to activate a number of membrane-bound enzymes. B ecause of the relationship between detergent action, relaxation of end othelium-intact rabbit aortic strips and the release of nitric oxide, we considered the possibility that other amphiphiles also produce nitr ic oxide from endothelial cells. We therefore investigated the effect of digitonin on relaxation of precontracted rabbit aortic strips and t he release of nitric oxide from freshly harvested bovine endothelial c ells as determined by chemiluminescence. We found that both digitonin and LPC release nitric oxide and that this process is inhibited by the NO synthase inhibitor N omega-Nitro-L-Arginine Methyl Ester (L-NNAME) .