The comparison of the antioxidant defense potential of brain to liver of rats after methanol ingestion.

The antioxidant enzymatic and nonenzymatic potential in the brain of rats given methanol orally was investigated for 7 days consecutively and compared to that one in the liver. Glutathione (GSH) and the activities of superoxide dismutase (Cu, Zn-SOD), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSG-R) were reduced in the brain after the first 24 h, whereas in the liver these parameters were diminished after 6 h. The brain catalase (CAT) activity was very low and constant in contrast to high and changeable CAT in the liver. At the beginning of intoxication, the activities of Cu, Zn-SOD and CAT in the liver were increased; after 5 days they were restored to normal values while Cu, Zn-SOD diminished gradually in the brain. An early change that occurred 6 h after intoxication was a decrease of ascorbate in the brain and in the liver. The increase in thiobarbituric acid-reactive substances (TBA-rs) in the liver was preceded by their increase in the brain. Our findings indicate decreased antioxidative potential both in the brain and in the liver of rats after methanol ingestion. The regulatory mechanisms of the antioxidant enzymes in the brain of intoxicated rats differ from those ones in the liver.