The effects of ethanol upon hydric balance and arterial pressure in rats: folic acid as a possible hypotensor.
Chronic alcohol intake is related to hypertension. There are, however, few studies concerning the effect of ethanol upon hydric balance in relation to arterial pressure. Folic acid intake has beneficial effects upon the cardiovascular system decreasing hyperhomocysteinemia, however, more studies imply that it is related with other mechanisms. Therefore, we have studied the effects of chronic alcohol intake (30% v/v) upon hydric-saline balance and hypertension and have found that dietary supplementation with folic acid (8 mg/kg) improves the above parameters. Our study used four experimental groups of rats: control, alcohol, alcohol with folic acid and control with folic acid. In all cases we measured the clearance of Na(+), K(+) and aldosterone; osmolarity in urine, liquid and solid ingestion; homocysteine levels in serum; cardiac frequency and arterial blood pressure. The alcohol intake increases serum aldosterone and homocysteine, which is reflected in an increase in arterial blood pressure. In addition, we have found that alcohol intake reduces both liquid and solid ingestion (causing a malnourishment status), the clearance of creatinine, aldosterone, Na(+) and K(+), and the ratio ClNa(+)/ClCr; it also increases urine osmolarity. Folic acid supplementation increases the clearance of Na(+) and the ratio ClNa(+)/ClCr. Folic acid intake improves the hypertension provoked by alcohol by increasing the aldosterone clearance, drastically reducing the serum levels of this hormone and thus its hypertensor effect.