Effects of selenite and selenomethionine on glutathione peroxidase in the rat.

The activity of glutathione (GSH) peroxidase (EC 1.11.1.9) decreased in tissues of rats fed a diet deficient in selenium. A single dose of 300 mug selenium by stomach tube increased GSH peroxidase activity within 48 hours. The effects of selenite and selenomethionine on GSH peroxidase activity were roughly similar. This study provides evidence that selenium from both selenite and selenomethionine is readily available for synthesis of the selenoenzyme GSH peroxidase in rat tissues.