Comparative Effect of Selenate and Selenite on Serum Selenium Concentration and Glutathione Peroxidase Activity in Selenium-Depleted Rats

The biological effect of selenate and selenite was compared in selenium-depleted rats by using both serum selenium concentration and glutathione peroxidase activity as an indicator of body selenium status. A single oral dose of selenium (125 micrograms/kg body weight) as sodium selenate or sodium selenite increased serum selenium concentration and glutathione peroxidase activity significantly (p less than 0.001). The effect of selenate and selenite on serum selenium and glutathione peroxidase activity was similar. Serum selenium concentration correlated positively with serum glutathione peroxidase activity both before (r = 0.815; p less than 0.001) and after (r = 0.800; p less than 0.001) treatment. These results indicate that the biological availability of selenate and selenite is similar.