ACETALDEHYDE METABOLISM - DIFFERENCES BETWEEN UCHA AND UCHB RATS

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 incubat ion with homogenates and subcellular fractions from liver and brain wa s determined. In addition, the effect of disulfiram pretreatment on Ac H metabolism was studied. Male adult rats of both strains were used. A DR was assayed in total homogenates, and in mitochondrial as well as 9 000 g supernatant fractions of liver and brain. AcH was measured by ga s chromatography. In some experiments, rats were pretreated with disul firam (300 mg/kg po) 24 hr before the studies. The result showed no st rain difference in ADR in homogenates or subcellular fractions of live r from untreated rats, but for disulfiram pretreated rats a significan tly lower decrease of ADR in samples from UChB compared to UChA rats w as 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). C oncerning brain homogenates, a higher ADR was observed in homogenates and crude mitochondrial fractions of UChB than of UChA rats. This diff erence was not observed when the incubation was performed without addi ng NAD or in the absence of oxygen. These results provide evidence of strain differences in mitochondrial AcH metabolism, the nature and ori gin of which deserve further study.