Intra-arterial vitamin C prevents endothelial dysfunction caused by ischemia-reperfusion.

Abstract Objective Ischemia-reperfusion (IR) injury causes tissue injury and endothelial dysfunction. There is evidence that oxidative stress plays an important role. Methods We tested if IR-induced endothelial dysfunction could be prevented by administration of the antioxidant vitamin C. Twenty-six healthy male subjects and eight male patients with peripheral arterial disease (PAD) were enrolled in this randomised placebo-controlled study. Forearm blood flow (FBF) measurements in response to the vasodilators acetylcholine (ACh; endothelium-dependent agonist) or nitroglycerin (NTG; endothelium-independent) were performed before and after forearm ischemia for 20 min. FBF responses were reassessed during reperfusion with intra-arterial co-administration of 24 mg/min vitamin C or placebo. In six volunteers responses to the NO-synthase inhibitor N -monomethyl- l -arginine ( l -NMMA) were also assessed before and after ischemia with and without vitamin C. Results ACh-induced vasodilation was blunted in subjects receiving placebo after reperfusion ( p p l -NMMA responses seen during reperfusion could be completly reversed by vitamin C. Conclusions Our data indicate that IR-induced vascular injury can be prevented by administration of antioxidants.