The Effect of Selenium on Antioxidant Defense System in the Blood of Rats Chronically Treated with Cadmium

The effect of selenium (Se, 7 μg/kg/day, during 30 days) on the antioxidant defense system (AOS): copper zinc containing superoxide dismutase (CuZn SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities in red blood cells (RBC) and glutathione-S-transferase (GST) activity in the plasma, as well as ascorbic acid (AsA) and vitamin E (Vit E) concentrations in the plasma of rats chronically treated with cadmium (Cd, 15 mg/kg/day, during 30 days) was analyzed. All results of experimental groups were compared with control animals. Cd led to increased the activities of CuZn SOD, CAT and GSH-Px, as well as GST activity and Vit E concentration. Se induced a significant increase in GSH-Px and GST activities, as well as concentrations of AsA and Vit E. In animals exposed both to Cd and Se a significant increase of GSH-Px activity was observed. The accumulation of Cd was significantly increased in the plasma of Cd+Se treated and in RBC of Cd treated animals, while it was markedly lower in RBC of Cd+Se treated rats. The obtained results show, that Cd exhibit toxic effects on the antioxidant defense system in the blood of rats and that Se demonstrates protective role against Cd toxicity.