INCREASED PLASMA ATRIAL-NATRIURETIC-PEPTIDE AFTER INGESTION OF LOW-DOSES OF ETHANOL IN HUMANS

Previous studies have demonstrated that, in human, acute consumption o f high doses of ethanol, administered in a large quantity of fluid, wi th or without volume-loading, induced either a decrease or an increase In the plasma content of atrial natriuretic peptide (ANP)-a substance that has a hypotensive effect. The objective of the present study was to examine the effect of low doses of ethanol (0, 0.25, and 0.50 g of ethanol/kg of body weight) administered to six normotensive individua ls, in a small volume of fluid without prior volume-loading. Before an d at various intervals after administration of the placebo or ethanol drinks, heart rate and brood pressure were measured and blood samples were taken for estimation of the plasma ANP, arginine vasopressin, and cortisol contents. Results indicated small changes in blood pressure and heart rate after ingestion of either the placebo or ethanol drinks . On the other hand, a significant increase in the plasma ANP content was observed at 15 min after ingestion of both the 0.25 and 0.50 g of ethanol/kg of body weight doses, but not after the placebo drink. Plas ma ANP levels were still elevated at 45 min postethanol intake, but ha d returned to basal levels at 120 min after the ethanol drink. Interes tingly, it was noticed that the higher dose of ethanol (0.50 g) did no t induce a higher plasma ANP concentration than the lower dose (0.25 g ) of ethanol; however, the plasma ANP content remained elevated for a longer period. Furthermore, the increase in plasma ANP content was not due to ethanol or stress-induced increases in the plasma arginine vas opressin and cortisol contents, because the plasma concentration of th ese hormones remained either at basal or below basal levels for the du ration of the experiment. In conclusion, ingestion of low amounts of e thanol equivalent to 1 or 2 standard drinks induced an increase in pla sma ANP content.