Free radical formation in livers of rats treated acutely and chronically with alcohol.

The spin trapping method was used to assess formation of free radical intermediates in vivo before and after acute alcohol administration to rats. Ascorbyl radicals and spin adducts of dietary alcohol or endogenous compounds, such as lipids, were detected with higher frequency in bile from alcohol-fed rats than in corresponding samples from rats fed control diets. When alcohol was given acutely to these animals, the 1-hydroxyethyl radical metabolite of ethanol was also formed at higher rates in livers of rats that had been fed ethanol chronically. Furthermore, formation of lipid radicals was enhanced after acute alcohol administration. These data support the hypothesis that chronic alcohol administration causes development of oxidative conditions in the liver, which subsequently lead to formation of differing types of radicals. Liver microsomes from alcohol-fed rats also metabolized ethanol to the 1-hydroxyethyl radical at higher rates than controls.