L‐Arginine inhibits xanthine oxidase‐dependent endothelial dysfunction in hypercholesterolemia

Abstract
Xanthine oxidase (XO)‐derived superoxide contributes to endothelial dysfunction in humans and animal models of hypercholesterolemia (HC). SinceL‐arginine supplementation prevents defects in NO signaling, we tested the hypothesis thatL‐arginine blunts the inhibitory effect of XO on vascular function. Acetylcholine‐mediated relaxation was significantly impaired in ring segments of HC rabbits, a response that was associated with an increase in plasma XO activity.L‐Arginine treatment of HC rabbits reduced plasma XO and improved endothelial function.L‐Arginine also modestly prolonged the lag time for oxidation in isolated lipoprotein samples. These results reveal that the principal action ofL‐arginine is to protect against the XO‐dependent inactivation of NO in arteries of HC rabbits.

This publication has 31 references indexed in Scilit: