Objective To study changes of DNA damage and oxidative stress in peripheral blood of rats induced by hexavalent chromium exposure through drinking water.
Methods Forty male and forty female SD rats were randomly divided into 4 groups with 10 in each group and 2 in each cage. The rats were exposed to potassium dichromate (K2Cr2O7) through drinking water at doses of 0, 30, 100, and 300 mg/L for 4 weeks, respectively. Water consumption per cage was recorded 3 times a week and the water was replaced by freshly prepared K2Cr2O7 solution. The rats were neutralized after 4 weeks. Body weight and weights of heart, liver, kidney, lung, stomach, and spleen were recorded, and organ coefficients and mean daily water consumption per rat were calculated. The DNA damage of whole blood cells and the contents of 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) in rat plasma samples were measured.
Results The body weight increment in the 300 mg/L female rat group was significantly lower than that of the controls (P<0.05). The mean daily water consumption per rat in the 300 mg/L female rat group and in both the 100mg/L and 300mg/L male rat groups was significantly decreased than that in the control group (P<0.05, P<0.01). Blood DNA damage increased significantly in both the male and female rats administrated with 300 mg/L K2Cr2O7 as compared with the controls (P<0.05). The contents of 8-OHdG in the 100 mg/L and 300 mg/L female rat groups were significantly increased (P<0.05, P<0.01). The contents of MDA in the plasma samples of female rats in all exposed groups and male rats in the 100 mg/L and 300 mg/L groups increased significantly compared with the controls (P<0.05, P<0.01).
Conclusion The increments of blood DNA damage and the contents of 8-OHdG and MDA in rat plasma may due to hexavalent chromium exposure through drinking water.
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