Abstract

In order to explore the influence of acetaldehyde (AcH) metabolism on the voluntary ethanol intake of genetically low (UChA) and high (UChB) ethanol consumer rats, the AcH disappearance rate (ADR) after incubation with homogenates and subcellular fractions from liver and brain was determined. In addition, the effect of disulfiram pretreatment on AcH metabolism was studied. Male adult rats of both strains were used. ADR was assayed in total homogenates, and in mitochondrial as well as 9000 g supernatant fractions of liver and brain. AcH was measured by gas chromatography. In some experiments, rats were pretreated with disulfiram (300 mg/kg po) 24 hr before the studies. The result showed no strain difference in ADR in homogenates or subcellular fractions of liver from untreated rats, but for disulfiram pretreated rats a significantly lower decrease of ADR in samples from UChB compared to UChA rats was observed. This result is consistent with a lower peak AcH level in UChB compared to UChA rats after a load of ethanol (60 mmole/kg ip). Concerning brain homogenates, a higher ADR was observed in homogenates and crude mitochondrial fractions of UChB than of UChA rats. This difference was not observed when the incubation was performed without adding NAD or in the absence of oxygen. These results provide evidence of strain differences in mitochondrial AcH metabolism, the nature and origin of which deserve further study.