THE COMPARISON OF THE ANTIOXIDANT DEFENSE POTENTIAL OF BRAIN TO LIVEROF RATS AFTER METHANOL INGESTION

The antioxidant enzymatic and nonenzymatic potential in the brain of r ats given methanol orally was investigated for 7 days consecutively an d compared to that one in the liver. Glutathione (GSH) and the activit ies 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 constan t in contrast to high and changeable CAT in the liver. At the beginnin g of intoxication, the activities of Cu; Zn-SOD and CAT in the liver w ere increased; after 5 days they were restored to normal values while Cu, Zn-SOD diminished gradually in the brain. An early change that occ urred 6 h after intoxication was a decrease of ascorbate in the brain and in the liver. The increase in thiobarbituric acid-reactive substan ces (TBA-rs) in the liver was preceded by their increase in the brain. Our findings indicate decreased antioxidative potential both in the b rain and in the liver of rats after methanol ingestion. The regulatory mechanisms of the antioxidant enzymes in the brain of intoxicated rat s differ from those ones in the liver. (C) 1998 Elsevier Science Inc. All rights reserved.