Moderate ethanol ingestion, redox status, and cardiovascular system in the rat

Abstract

Moderate intake of alcoholic beverages decreases the incidence of cardiovascular pathologies, but it is in dispute if cardioprotective effects are due to ethanol, to polyphenolic compounds present in beverages or to a combination of both. In humans, effects of high, moderate, and low doses of alcoholic beverages are widely studied, but effects of pure alcohol remain unclear. On the other hand, experiments with laboratory animals are centered on high toxicological doses of ethanol but not on low doses. In the present study, we have aimed to mimic in the rat the pattern of alcohol intake in Mediterranean population. Alcohol ingestion is spread along the day and not always related to solid food consumption. We tried to define the beneficial and harmful effects of pure ethanol ingestion without polyphenol’s influence. Experimental rats were given 1% ethanol in their drinking water for 30 days, resulting in a daily ingestion of 0.27 mL of ethanol/rat/d. Ethanol ingestion did not cause deleterious effects on the general status of the animals, but it decreased cholesterol, triglycerides, and catecholamine stores’ rate of utilization in peripheral sympathetic system. Moreover, ethanol lowered pulmonary arterial pressure and did not alter systemic arterial pressure. In the liver, the reduced glutathione/oxidized glutathione ratio was augmented and lipid peroxide, superoxide dismutase, and glutathione peroxidase activities were decreased. However, catalase activity was unaltered. Liver cytochrome P4502E1 distribution and protein level and activity were unchanged by ethanol ingestion. Data indicate a lack of harmful effects and underscore a set of potentially beneficial effects of this dose of ethanol.