Subchronic exposure to arsenic trioxide-induced oxidative DNA damage in kidney tissue of mice

To evaluate the oxidative DNA damage in kidney tissue of mice exposed to arsenic trioxide (As) subchronically, expression of 8-hydroxy-2-deoxyguanosine (8-OHdG) and pathologic changes were observed. Forty mice were randomly divided into 4 groups of 10 each (5 mice of each sex). Group 1 received drinking water alone (control). Groups 2, 3 and 4 received 1, 2 and 4 mg/L arsenic trioxide, respectively. Arsenic trioxide was given through drinking water for 60 days. The expression of 8-OHdG in the kidney tissue of mice was analyzed observed in these 4 groups. The groups treated with As showed pathologic changes in the kidney tissue and significant increase in the level of 8-OHdG expression (P<0.01). Moreover, the dose-dependent increase between As exposure and renal damages were observed. Especially, its immunoactivity was strong in the proximal convoluted tubule and Bowman's capsule. These results suggest that chronic exposure to As induces damages to kidney tissue, and especially the epithelial cells of proximal convoluted tubule and the podocytes of the Bowman's capsule may be more sensitive to As-induced nephrotoxicity.