EN
The experiment was performed on Sprague-Dawley male rats weighing 203, 103 and 53 g, and female 99 g. Animals were fed for 2 weeks a diet containing 0,1 and 2,0 ppm of Se (Na₂ SeO₃ added). It was observed that the daily Se intake per kg of BW is lowered with an increase in animals body weight. Se-supplementation caused a significant increase of Se content in plasma and red blood cells. The highest concentration of Se in plasma and in RBC was found in females. GSH-Px activity was higher in RBC of all male rats receiving a Se-supplemented diet, but not in females. In plasma these differences between Se-adequate and supplemented rats were significant in youngest male rats and in females. These results suggest that age and sex of rats affect the concentration of Se and GSH-Px activity in plasma and RBC of rats.