Impairment of Endothelial Functions by Acute Hyperhomocysteinemia and Reversal by Antioxidant Vitamins

Our data suggest that mild to moderate elevations of plasma homocysteine levels in healthy subjects activate coagulation, modify the adhesive properties of endothelium, and impair the vascular responses to L-arginine. Pretreatment with antioxidant vitamin E and ascorbic acid blocks the effects of hyperhomocysteinemia, suggesting an oxidative mechanism.