Oxygen free radical production in rat liver: dose-related effect of ethanol on reperfusion injury.

Ethanol is known to have a deleterious effect on liver ischemia-reperfusion injury, but recent reports suggest that light ethanol consumption may produce a protective effect in several organs. We aimed to investigate effects of different doses of ethanol on liver oxidative injury. Rats were fed with ethanol-containing diets (24, 30, 36, 40% for groups A, B, C, D, respectively). After four weeks, livers were exposed to ischemia-reperfusion. Chemiluminescence was recorded; total lipids, adenosine triphosphate, malondialdehyde, reduced glutathione and lactic dehydrogenase were assessed. In all groups, ischemia resulted in the disappearance of O2*-, a decrease in glutathione and adenosine triphosphate, and stable malondialdehyde values. During the reperfusion phase, O2*- production, malondialdehyde and lactic dehydrogenase increased, reaching significantly higher values in groups C and D and significantly lower values in group B. The effect of ethanol on ischemia-reperfusion injury seems to be a dose-related response, with an additional toxic effect only at high doses of ethanol.