Acceleration of ethanol and acetaldehyde oxidation by D-glycerate in rats

The aim of the present study was to investigate whether d-glycerate (glycerate) could accelerate ethanol and acetaldehyde (AcH) oxidation in vivo in rats by circumventing the rate-limiting step, that is, the reoxidation of the reduced form of nicotinamide adenine dinucleotide. Male rats belonging to the ANA (Alko, nonalcohol) and AA (Alko, alcohol) rat lines were challenged with 1.2 g ethanol per kilogram with or without glycerate administration (0.1-1.0 g/kg). Blood ethanol, blood AcH, and liver free glycerol concentrations were determined during ethanol intoxication. Glycerate treatment, regardless of the dose, accelerated ethanol elimination by approximately 25% (P < .001) in the ANA animals. Glycerate also accelerated the AcH oxidation, but perhaps not as much as the ethanol oxidation, as indicated by a trend toward elevated AcH levels. In the experiments with the AA rats, glycerate treatment elevated hepatic free glycerol levels by about 50% (P < .05) during alcohol intoxication. The acceleration of ethanol and AcH oxidation in conjunction with elevated glycerol levels by the treatment with glycerate supports the hypothesis that the aldehyde dehydrogenase-mediated AcH oxidation can be coupled with the reduction of glycerate to d-glyceraldehyde catalyzed by the same enzyme. Such a coupling should increase the availability of the oxidized form of nicotinamide adenine dinucleotide and thus accelerate both ethanol and AcH oxidation. Further studies are needed to investigate how the AcH could be even more efficiently oxidized to reduce the harmful effects of ethanol-derived AcH.