Dietary vitamin B6 supplementation prevents ethanol-induced hypertension in rats

Background and Aims: All known pathways of ethanol metabolism result in the production of acetaldehyde, a highly reactive compound. Acetaldehyde has b een shown to deplete vitamin B6 in chronic alcoholics. It also binds with s ulfhydryl groups of membrane proteins, altering membrane Ca2+ channels and increasing vascular cytosolic free calcium, peripheral vascular resistance and blood pressure. The aldehyde-binding thiol compound, N-acetyl cysteine, attenuates elevated blood pressure and associated adverse changes in ethan ol-induced hypertensive rats. Vitamin B6 supplementation increases the leve l of endogenous cysteine. Aim of this work was thus to investigate whether a dietary supplementation of vitamin B6 can prevent ethanol-induced hyperte nsion and associated changes in Wistar-Kyoto (WKY) rats. Methods and Results: Starting at 7 weeks of age, WKY rats were divided into three groups of six animals each. The control group received a normal vita min B6 diet (regular chow) and normal drinking water, the ethanol group, th e same diet pills 1% ethanol in the drinking water, and the ethanol + vitam in B6 group a high vitamin B6 diet (20 times normal diet) and 1% ethanol in the drinking water. After 14 weeks, systolic blood pressure, platelet [Ca2 +](i) and kidney and aortic aldehyde conjugate levels were significantly hi gher in the ethanol group. These rats also showed smooth muscle cell hyperp lasia in the small arteries and arterioles of the kidneys. Dietary vitamin B6 supplementation prevented these changes. Conclusions: Dietary vitamin B6 supplementation prevented ethanol-induced h ypertension and associated changes in WKY rats by normalizing tissue aldehy de conjugate levels. (C) 1999, Medikal Press.