DIFFERENCE IN EFFECTS OF CLASSIC AND PHOSPHOLIPID HYDROPEROXIDE GLUTATHIONE PEROXIDASES ON LIVER LIPID PEROXIDE LEVEL IN SELENIUM-DEFICIENTRATS

When weanling male rats of the Wistar strain were fed a selenium-defic ient diet, the activity of classic glutathione peroxidase (GPx) in liv er cytosol decreased rapidly. In contrast, the activity of phospholipi d hydroperoxide GPx (PHGPx) in the cytosol decreased only slowly. Desp ite the marked decrease in classic GPx activity, the lipid peroxide le vel in the liver did not change until 6 weeks after the start of the f eeding, whereas the level was significantly increased by 9 weeks, by w hich time PHGPx activity and its protein level had markedly diminished . These data indicate that PHGPx is much more crucial than classic GPx in preventing the elevation of liver lipid peroxide level in selenium -deficient rats.