title: Glutathione peroxidase activity in bovine serum and erythrocytes in relation to selenium concentrations of blood, serum and liver.
abstract: The concentration of selenium (Se) in liver, serum and whole blood, and the activity of glutathione peroxidase (GSH-px) in serum and erythrocytes were monitored for seven months after the administration of Se to Se-deficient calves. There was a rapid increase in Se concentration in liver and serum, followed by an exponential decline with half-lives of 22.1 +/- 0.2 days and 28.3 +/- 2.0 days respectively. Whole blood Se concentration also increased rapidly but declined more slowly than liver or serum Se concentraations. The rise in Se concentration and GSH-px activity in erythrocytes was delayed and both levels remained elevated several months after liver and serum Se concentrations had become marginal or deficient. GSH-px activity in serum increased more rapidly after dosing and declined more rapidly than GSH-px activity in erythrocytes. The results suggest that liver and serum Se concentration and serum GSH-px activity respond to changes in dietary Se intake more rapidly than either whole blood Se or erythrocyte GSH-px activity. Two-monthly administrations of Se, at the current recommended therapeutic dose (0.1 mg Se/kg as sodium selenate) appears to be necessary to maintain adequate Se levels in calves on Se-deficient pasture.
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood / Q000378:metabolism*; D002418:Cattle Diseases / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology*; D005979:Glutathione Peroxidase / Q000097:blood*; D008099:Liver / Q000378:metabolism*; D010544:Peroxidases / Q000097:blood*; D012643:Selenium / Q000097:blood / Q000172:deficiency / Q000378:metabolism*
chemical_list: D010544:Peroxidases; D005979:Glutathione Peroxidase; D012643:Selenium