Ethanol and acetaldehyde metabolism in the pregnant mouse

Liver aldehyde dehydrogenase (ALDH) activity was found to be two-fold greater in pregnant (days 16-20 of gestation) mice than in non-pregnant controls. A subcellular fractionation revealed that the increase in ALDH activity was confined to the cystosolic fraction of the liver. Kinetic characterization of partially purified liver ALDH revealed similar Km values for either acetaldehyde or propionaldehyde in pregnant and non-pregnant animals. The similarity of apparent Km values suggests that the increase in cytosolic ALDH may involve induction of normally present ALDH isozyme, rather than originating from synthesis of a new enzyme. Induction of liver ALDH was found to significantly decrease blood acetaldehyde concentrations in pregnant mice receiving 2.0 or 3.0 g/kg ethanol when compared to the respective control (non-pregnant) animals. However, differences in blood acetaldehyde levels measured in pregnant and control animals were not apparent when blood ethanol concentrations were below 40 mumol/ml.