Aldehyde dehydrogenase (E.C. 1.2.1.3) in chronic alcoholic liver diseases

Acetaldehyde dehydrogenase (ALDH) activity in liver biopsy specimens was considerably reduced in alcoholic cirrhosis (n = 5), elevated in alcoholic fatty liver (n = 11)--probably due to enzyme induction--only slightly elevated in alcoholic hepatitis (n = 6), but unaffected in non-alcoholic liver diseases (n = 23) in comparison with specimens obtained from patients with minimal liver lesions. We will argue as a working hypothesis that alcoholics with induced ALDH activity will mainly develop fatty liver, whereas reduced hepatic ALDH appears to be a reason for elevated acetaldehyde levels followed by additional liver injury and progression at least for alcoholic cirrhosis.