Effect of Dietary Selenium on Glutathione Peroxidase in the Chick

Abstract
Tissues of chicks fed a diet deficient in selenium demonstrated decreased glutathione (GSH) peroxidase activity. GSH peroxidase activity was doserelated to the level of selenium; the specific activity increased as a logarithmic function of the dietary selenium level. Essentially, there was no difference between the activity of GSH peroxidase in various tissue soluble fractions from chicks fed equal gram-atoms of selenium as sodium selenite and as selenomethionine. Regression analysis of pooled data for GSH peroxidase and GSH reductase activities in tissues of chicks fed 0.1 ppm selenium indicated a linear relationship between the two enzymes. These data support the hypothesis that GSH peroxidase and GSH reductase are metabolically related. GSH reductase activity was not related to dietary selenium levels. The implications of this study are that GSH peroxidase is dependent upon selenium for activity and that it also is a part of a detoxification system for peroxides.