Decreased antioxidant defense mechanisms in rat liver after methanol intoxication

The primary metabolic fate of methanol is oxidation to formaldehyde and then to formate by enzymes of the liver. Cytochrome P-450 and a role for the hydroxyl radical have been implicated in this process. The aim of the paper was to study the liver antioxidant defense system in methanol intoxication, in doses of 1.5, 3.0 and 6.0 g/kg b.w., after methanol administration to rats. In liver homogenates, the activities of Cu,Zn-superoxide dismutase and catalase were significantly increased after 6 h following methanol ingestion in doses of 3.0 and 6.0 g/kg b.w. and persisted up to 2-5 days, accompanied by significant decrease of glutathione reductase and glutathione peroxidase activities. The content of GSH was significantly decreased during 6 hours to 5 days. The liver ascorbate level was significantly diminished, too, while MDA levels were considerably increased after 1.5, 3.0 and 6.0 g/kg b.w. methanol intoxication. Changes due to methanol ingestion may indicate impaired antioxidant defense mechanisms in the liver tissue.