Differential response of cellular antioxidant mechanism of liver and kidney to arsenic exposure and its relation to dietary protein deficiency

The effect on antioxidant defense system of liver and kidney of sub-acute i .p. exposure to sodium arsenite (3.33 mg/kg b.w. per day for 14 days was st udied in male Wistar rats fed on an adequate (18%) or a low (6%) protein di et. Following arsenic treatment, liver showed significantly enhanced concen tration of glutathione and increased activities of glutathione reductase an d glutathione-S-transferase on either of the dietary protein levels. Liver glutathione peroxidase and glucose-6-phosphate dehydrogenase activities inc reased significantly on an adequate protein diet while glutathione peroxida se activity decreased significantly on a low-protein diet. Lipid peroxidati on and superoxide dismutase activity of liver remained unaltered on either of the dietary protein levels. On the other hand, kidney of arsenic-treated rats receiving either of the dietary protein levels showed significantly i ncreased lipid peroxidation and decreased superoxide dismutase and catalase activities. Kidney glutathione content and glutathione reductase activity remained unaltered while glutathione peroxidase activity increased and glut athione-S-transferase activity decreased significantly on a low-protein die t following exposure to arsenic. On an adequate protein diet glucose-6-phos phate dehydrogenase activity in kidney, however, became significantly eleva ted following arsenic treatment. In Wistar rats, after 14 days of treatment with 3.33 mg As/kg b.w. i.p. the kidney seemed to be more sensitive to ars enic, and liver appears to be protected more by some of the antioxidant com ponents, such as, glutathione, glutathione-S-transferase and glucose-6-phos phate dehydrogenase. It appears that low-protein diet influences the respon se of some of the cellular protective components against arsenic insult but does not lead to unique findings. (C) 2000 Elsevier Science B.V. All right s reserved.