Human Placental Aldehyde Dehydrogenase

Publisher Website
Google Scholar
Abstract
Freshly obtained human term placentae were subjected to subcellular fractionation to study the localization of NAD-dependent aldehyde dehydrogenases. Optimal conditions for the cross-contamination-free subcellular fractionation were standardized as judged by the presence or the absence of appropriate marker enzymes. Two distinct isozymes, aldehyde dehydrogenase I and II, were detected in placental extracts after isoelectric focusing on polyacrylamide gels. Based on a placental wet wt, about 80% of the total aldehyde dehydrogenase activity was found in the cytosolic and about 10% in the mitochondrial fraction. The soluble fraction (cytosol) contained predominantly aldehyde dehydrogenase II which has a relatively high Km (9 mmol/l) for acetaldehyde and is strongly inhibited by disulfiram. The results indicate that cytosol is the main site for acetaldehyde oxidation, but the enzyme activity is too low to prevent the placental passage of normal concentrations of blood acetaldehyde (< 1 .mu.mol/l) produced by maternal ethanol metabolism. [Impaired acetaldehyde metabolism leading to an increased blood acetaldehyde level after alcohol consumption may be responsible for the pathogenesis of alcoholism as well as fetal alcohol syndrome.].

This publication has 2 references indexed in Scilit: