Selenium-induced activation of brain Na(+)-K(+)-ATPase in rats.

The influence of selenium supplementation on the activity of Na(+)-K(+)-ATPase and on the degree of free radical generation was studied in brain tissue of rats. Selenium was administered for 5 months in drinking water, and was measured in plasma by the fluorometric method at the end of the experimental period. Animals were sacrificed and brain tissue homogenates were used for enzyme assay and for assessment of lipid peroxide formation. Brain tissue from rats who received selenium showed significantly increased Na(+)-K(+)- ATPase activity but also significantly decreased lipid peroxide farmation. Since this enzyme is known to be inhibited by oxygen free radicals, selenium supplementation appears to exert a beneficial effect on the Na(+)-K(+)-ATPase activity by preventing free radical-induced damage.