Total sulfhydryl groups (TSH), reduced glutathione (GSH), glutathione reductase (GR), and glutathione- S -transferase (GST) 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 = 5 per group). GR activity, TSH levels, and GSH levels are significantly increased after exposure to Cd, while GST activity is significantly increased. The administration of DMS to Cd-exposed rats ameliorates or reverses the changes of enzyme activities or levels. The data represent means ± standard error of the mean (SEM).