Liver cytosolic aldehyde dehydrogenase (ALDH1) polymorphism and its inheritance in Wistar rats

Rats are very important experimental animal to study alcohol related problems. Liver aldehyde dehydrogenases (ALDHs) which metabolize aldehydes are reported to have several isozymes which are distributed in mitochondrial, microsomal and cytosolic fractions. However, there is discrepancy on reports concerning properties of cytosolic ALDH from normal liver. We report here the liver cytosolic ALDH (ALDH1) polymorphism and its inheritance in Wistar rats. Isoelectrophoretic focusing technique reveals the three ALDH1 phenotypes (termed AA, AC and CC) which are inherited in accordance with Mendelian fashion, indicating the existence of two alleles, ALDH1A and ALDH1C. In the range of pI 5.3 to 5.8, the AA phenotype possesses a major anodic band with pI 5.3 and CC phenotype also has a cathodic pI 5.8 band. In contrast, AC phenotype exhibits five bands with pIs of 5.3, 5.4, 5.5, 5.7 and 5.8. Intensity of these bands gradually diminishes from the main band with pI 5.5 to the both opposite ends. These findings suggest that AC phenotype as well as AA and CC types has a structure of tetramer which consist of the combination of subunit of the A and C gene products.