Cu, Zn-Superoxide dismutase 1 (SOD1), catalase (CAT), and glutathione peroxidase (GPx) activity in the hippocampi of control, DMS-, Cd-, Cd-DMS-treated rats. * Indicates a significant difference between the control and Cd groups (P <0.05); # indicates a significant difference between the Cd and Cd/DMS groups (P <0.05; n = 7 per group). Antioxidant enzyme activities are significantly lower in the Cd group and the administration of DMS to Cd-exposed rats ameliorates the reduction of enzyme activities. The effect on GPx activity is greater than that on SOD1 or CAT activities. The data represent means ± standard error of the mean (SEM).