Effect of acetaldehyde on ethanol- and aldehyde-metabolising systems of the liver and brain of rats

Lately the mechanism of craving for alcohol has been related to the local level of brain acetaldehyde occurring in ethanol consumption and depending on the activities of the brain and liver ethanol and acetaldehyde-metabolizing systems. In this connection, we studied the effect of chronic acetaldehyde intoxication on the activities of alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), the microsomal ethanol oxidizing system (MEOS) and liver and brain catalase as well as ethanol and acetaldehyde levels in the blood. The results showed that the chronic acetaldehyde intoxication did not alter significantly the activities of liver ADH, MEOS and catalase as well as liver and brain ALDH. In parallel with this, the systemic acetaldehyde administration led to shortened time of ethanol narcosis and activation of catalase in the cerebellum and left hemisphere, which may indicate involvement of this enzyme into metabolic tolerance development.