In the present study, the changes in the production of the superoxide radicals, hydrogen peroxides and lipid peroxides and the activities of superoxide dismutase (EC 1. 15. 1. 1, SOD) and catalase (EC 1. 11. 1. 6) in the rats´ brains that were treated with diethyldithiocarbamate (DDC), 1,000mg/kg body weight were observed.
The results were summarized as follows:
1. At lhr after the administration of DDC, the homogenates of rats´ brains showed a considerably lower activity of Cu,Zn-SOD when compared with those of the control rats (p<0.01). Activity of Cu,Zn-SOD in the brains increased sequentially after the administration of DDC and were similar to the control rats at 7hr and 15hr.
2. Activity of Mn-SOD in the brains of rats treated with DDC were lower at 1hr,"and the activity increased sequentially. Eventually at 15hr after the administration of DDC, the activity of Mn-SOD become significantly higher than those in the control group (p<0.05).
3. At 1hr after the administration of DDC, the rats´ brains showed a considerably higher activity of catalase than those in the control group (p<0.05), and the activity increased sequentially. Therefore at 15hr after treatment with DDC, the activity of catalase increased approximately 6 times its control value.
4. In the brains of rats treated with DDC, the production of superoxide radicals appeared to be very high in comparison with those in the control groups (p<0.01). But the sequential changes in its production were negligible.
5. Most of homogenates prepared from the brains of rats treated with DDC showed the hydrogen peroxide production similar to those in the control group.
6. At 1hr after the administration of DDC, the production of lipid peroxides was .considerably higher than those in the control group (p<0.01). Lipid peroxides production in the brains decreased sequentially at lhr, 3hr, 7hr and 15hr after the administration of DDC´ (p<0.01). But, the brains of most rats treated with DDC showed higher production of lipid peroxides than the controls.: From the above results, it seems likely that the administration of DDC, and copper and metalloen-
zyme irreversible inhibitor, resulted inthe development of the oxygen toxicity in rats´"brains through
oxygen radicals production. Accordingly, the SOD and catalase in the brain could protect the brain effectively from the oxygen toxicity and the lipid peroxidation following the oxygen radical production.
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