Nitroarginine inhibits endothelium-derived relaxation.

Effects of NG-nitro-L-arginine (NO2Arg), a guanidinonitro arginine derivative, on acetylcholine-induced relaxation of rabbit thoracic aorta ring preparation were studied. Relaxation by acetylcholine was inhibited by NO2Arg dose-dependently and the maximum relaxation with 10(2) microM NO2Arg was reduced to 10.1 +/- 4.3% (n = 5). L-arginine (10(2) microM) did not affect the acetylcholine-induced relaxation. Relaxation by glyceryltrinitrate or papaverine was not affected by NO2Arg. These results indicate that NO2Arg is a novel inhibitor of endothelium-derived relaxation.