L-canavanine selectively augments contraction in aortas from endotoxemic rats

Contractile responses to KCl or phenylephrine were inhibited in endothelium-denuded aorta from endotoxin-treated rats. L-Canavanine, a selective inhibitor of inducible nitric oxide synthase, augmented contractile responses in vessels from endotoxin, but not saline-pretreated animals. In contrast to nitroarginine, L-canavanine did not inhibit endothelium-dependent relaxation induced by acetylcholine. Selective inhibitors of inducible nitric oxide synthase may be useful probes of vascular dysfunction in sepsis.