engleski

Effect of selenium pre-treatment on cadmium content and enzymatic antioxidants in tissues of suckling rat

Neonates are a group of special concern regarding higher absorption and retention of cadmium (Cd) compared to adults. Selenium (Se) prevents the toxicity of Cd through still undefined mechanisms. Cadmium has indirect role in free radical generation. Studies have shown that free radical scavengers and antioxidants are useful in protecting against Cd toxicity. This protective effect has not yet been studied in the early postnatal period. The effect of Cd on the activity of two antioxidant enzymes, glutathione peroxidase (GSH-Px) and superoxid dismutase (SOD), was studied in the liver, kidney and brain of suckling Wistar rats. Also, the influence of Se on Cd body burden of sucklings was evaluated. Rats were orally exposed to CdCl2xH2O and/or Na2SeO3 in equimolar amounts from day 6 to day 14 after birth. After 4 days of pre-treatment with Se, rats were concurrently treated for 5 days with Cd and Se (8 μ mol/kg/day, each). Cadmium exposure had no effect on both SOD and GSH-Px activities in kidney and brain whereas in liver activities were increased. Selenium exposure increased both enzyme activities in all organs (except SOD in liver). Concurrent administration of Se and Cd elevated both enzyme activities in kidney and brain compared to Cd and control group up to the levels found in Se treated animals. The same treatment showed opposite action on tissue Cd content: Se significantly lowered Cd burden in the order liver > kidney > brain. It can be concluded that selenium had positive effect on reduction of Cd body burden as well as on enzyme activities in kidney and brain.

cadmium; glutathione peroxidase; rats; selenium; superoxid dismutase; tissue concentration

nije evidentirano