Activity and electrophoretic profiles of brain aldehyde dehydrogenases in mice genetically selected for their ethanol preference.

The activities and electrophoretic profiles of NAD+-aldehyde dehydrogenases (EC 1.2.1.3, ALDHs) in the different brain regions from the mice of inbred C57BL/6J strain (alcohol preferring) and DBA/2 strain (alcohol avoiding) were studied. Kinetic studies on ALDH of the different brain regions revealed the existence of at least two ALDHs in both strains. The ALDH activity in the cerebellum, which was measured spectrophotometrically with 0.1 and 5 mM acetaldehyde as the substrates, was the highest of the three regions and it was about 2-fold higher than that in the cortex in both strains. The ALDH activities of mice of DBA/2 strain were higher than those of mice of C57BL/6J strain in all the regions. Only in the cortex the F1 hybrids (intermediate alcohol preferring) between C57BL/6J and DBA/2 strains had intermediate ALDH activity between their parental strains. Electrophoretic analysis of cortex ALDH revealed that strain differences were observed in the isozyme pattern between pH 7.2 and 7.8 with either acetaldehyde or propionaldehyde as substrate. These findings suggest that the ALDH activity in the cerebral cortex could be related to alcohol preference.