Abstract
To determine species differences in the hepatic lobular distribution of low Km aldehyde dehydrogenase (ALDH, ALDH 1+ALDH 2) activity (substrate, 50 μM acetaldehyde), the activity in Wistar rats and Hartley guinea pigs was examined histochemically by the nitroblue tetrazolium method. In the rat liver, low Km ALDH activity was observed throughout the lobules, with enhanced centrilobular staining. Interestingly, the guinea pig liver exhibited a U-shaped lobular distribution, with even localization in both the centrilobular and periportal zones, but with little activity in the midlobular region. These findings indicate that the distribution pattern of low Km ALDH activity in the hepatic lobule of guinea pigs differs strikingly from that of rats, hamsters and mice. This study shows that rodents, which are widely utilized as experimental animals, differ as much in the hepatic lobular distribution of low Km ALDH activity as in that of ADH activity, indicating that the species most suitable to the purpose of ethanol studies should be selected according to the profiles of the liver ADH and low Km ALDH activities.
