Intralobular distribution of class I alcohol dehydrogenase and aldehyde dehydrogenase 2 activities in the hamster liver.

The hepatic lobular localization of class I alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) 2 activities was examined histochemically using livers of hamsters with high ethanol preferences. The activity of class I ADH detected by the nitro blue tetrazolium method using 5 mM ethanol as a substrate was extremely high and was almost homogeneously distributed throughout the lobule. The ALDH 2 activity (substrate, 8 microM acetaldehyde) was localized to the centrilobular zone, whereas low Km ALDH (ALDH 1 + ALDH 2) activity (substrate, 50 microM acetaldehyde) showed a gradient distribution in the lobule with high centrilobular to moderate periportal activity, suggesting that the ALDH 1 activity was distributed throughout the lobule.