Liver superoxide dismutases and catalase during ethanol inhalation and withdrawal

Manganese superoxide dismutase (Mn-SOD) studied during ethanol vapor inhalation shows no changes during the inhalation period (4 days) and a transient increase 12 hours after ethanol withdrawal. A significant decrease in cytosolic Cu-Zn-SOD is found at the end of the inhalation period and was sustained during 48 hours following ethanol withdrawal. It is suggested that this decrease in Cu-Zn-SOD activity might be related to an inactivation of the enzyme linked to the increase in hydroxyl radical production related to ethanol metabolism. Cytosolic catalase is reduced at the end of the ethanol inhalation period. This decrease could be related to an enhanced superoxide radical concentration linked to the reduced Cu-Zn-SOD activity.