Hypoxic pulmonary vasoconstriction is enhanced by inhibition of the synthesis of an endothelium derived relaxing factor

Inhibition of the synthesis of endothelium derived relaxing factor by N G-monomethyl-L-arginine, a competitive inhibitor of the synthesis of nitric oxide from L-arginine, enhances hypoxic pulmonary vasoconstriction in pulmonary artery rings and isolated, Krebs albumin perfused rat lungs. L-arginine rapidly reduces hypoxic vasoconstriction, particularly in lungs treated with N G-monomethyl-L-arginine. Following administration of N G-monomethyl-L-arginine, bradykinin-induced vasodilation is inhibited (p