LIPID-PEROXIDATION AND ANTIOXIDANT DEFENSE ENZYMES IN VARIOUS REGIONSOF ADULT-RAT BRAIN AFTER COEXPOSURE TO CADMIUM AND ETHANOL

Effect of cadmium (1 mg/kg body weight) and ethanol (2 g/kg body weigh t) exposure, alone as well as in combination, on essential trace metal homeostasis, lipid peroxidation and antioxidant defense enzymes in va rious regions of the adult rat brain was investigated. It was observed that cadmium when administered alongwith ethanol accumulated signific antly in corpus striatum (3.5 fold) and cerebral cortex (3.0 fold) com pared to the cadmium treated group. The ethanol induced accumulation o f cadmium led to significant depletion in the levels of essential trac e metals like zinc and copper in these regions of the brain. Further, cadmium or ethanol alone did not show any significant effect on lipid peroxidation and antioxidant defense enzymes in any of the regions of the adult brain but when given in combination, caused a significant in crease in lipid peroxidation and markedly decreased the activities of antioxidant defense enzymes like glutathione peroxidase, superoxide di smutase and catalase particularly in corpus striatum and cerebral cort ex. Structural alterations produced by increased lipid peroxidation af ter cadmium and ethanol co-exposure may have profound effect on the ac tivities of membrane bound enzymes and hence may lead to functional im pairment. The results of the present study imply that ethanol renders the adult brain more susceptible to the neurotoxic effects of cadmium. Corpus striatum and cerebral cortex are more vulnerable to the toxic effects of cadmium under the influence of ethanol than other regions o f the brain.