Diurnal rhythm of ethanol metabolism in the rat.

Male Sprague-Dawley rats injected with 2.0 g/kg of ethanol and analyzed 1 h later at 8 specific times of the day showed diurnal rhythms for alcohol concentrations in the blood, urine, brain and liver tissues. The circadian fluctuation noted for the concentrations of blood and tissue ethanol might indicate a diurnal variation in the enzymatic metabolism of ethanol.