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.