Effect of Ethanol on Mouse Liver Monoamine Oxidase

The effects of ethanol and acetaldehyde on monoamine oxidase activity in mouse liver mitochondrial fraction were studied. In vivo, a single dose of ethanol increased the hepatic monoamine oxidase activity compared to control group, and chronic ethanol consumption also increased the enzyme activity using tyramine, benzylamine or serotonin as substrate. Acetaldehyde, the metabolite of ethanol, significantly increased monoamine oxidase activity more than ethanol did. In contrast to the in vivo results, it was found that the monoamine oxidase activity was inhibited in vitro by ethanol or acetaldehyde in the dose-dependent manner.