Low ethanol intake prevents salt-induced hypertension in WKY rats

Abstract

Low alcohol intake in humans lowers the risk of coronary heart disease and may lower blood pressure. In hypertension, insulin resistance with altered glucose metabolism leads to increased formation of aldehydes. We have shown that chronic low alcohol intake decreased systolic blood pressure (SBP) and tissue aldehyde conjugates in spontaneously hypertensive rats and demonstrated a strong link between elevated tissue aldehyde conjugates and hypertension in salt-induced hypertensive Wistar-Kyoto (WKY) rats. This study investigated the antihypertensive effect of chronic low alcohol consumption in high salt-treated WKY rats and its effect on tissue aldehyde conjugates, platelet cytosolic free calcium ([Ca2+]i, and renal vascular changes. Animals, aged 7 weeks, were divided into three groups of six animals each. The control group was given normal salt diet (0.7% NaCl) and regular drinking water; the high salt group was given a high salt diet (8% NaCl) and regular drinking water; the high salt + ethanol group was given a high salt diet and 0.25% ethanol in drinking water. After 10 weeks, SBP, platelet [Ca2+]i, and tissue aldehyde conjugates were significantly higher in rats in the high salt group as compared with controls. Animals on high salt diets also showed smooth muscle cell hyperplasia in the small arteries and arterioles of the kidney. Ethanol supplementation prevented the increase in SBP and platelet [Ca2+]i and aldehyde conjugates in liver and aorta. Kidney aldehyde conjugates and renal vascular changes were attenuated. These results suggest that chronic low ethanol intake prevents salt-induced hypertension and attenuates renal vascular changes in WKY rats by preventing an increase in tissue aldehyde conjugates and cytosolic [Ca2+]i.