LACK OF EFFECT OF VITAMIN-E ADMINISTRATION ON BASAL NITRIC-OXIDE FUNCTION IN MALE SMOKERS AND NONSMOKERS

1. The antioxidant properties of vitamin E (alpha-tocopherol) have been proposed to account for a possible protective effect in coronary artery disease, Coronary risk factors are associated with depressed endothelium-derived nitric oxide responses, and some evidence suggests increased quenching of the vasodilator effect of nitric oxide by oxygen free radicals, This study examined the possibility that vitamin E supplementation would improve basal function of the nitric oxide dilator system in long-term smokers and non-smokers. 2. Nine healthy male life-long non-smoking subjects and eight smokers (36+/-6 cigarettes per day, >7 years) were given 1000 i,u, of vitamin E per day for a 4-week period, while five additional non-smokers received placebo, Forearm blood flow responses to intra-arterial infusion of noradrenaline (60, 120 and 240 rho mol/min) and the competitive inhibitor of nitric oxide synthesis, N-G-monomethyl-L-arginine (1, 2 and 4 mu mol/min) were measured before and after therapy, 3, No changes were evident in the constrictor responses to noradrenaline or N-G-monomethyl-L-arginine in any group, These results indicate that vitamin E supplementation does not influence basal activity of the nitric oxide-dilator system irt vivo.