Difference in effects of classic and phospholipid hydroperoxide glutathione peroxidases on liver lipid peroxide level in selenium-deficient rats.

When weanling male rats of the Wistar strain were fed a selenium-deficient diet, the activity of classic glutathione peroxidase (GPx) in liver cytosol decreased rapidly. In contrast, the activity of phospholipid hydroperoxide GPx (PHGPx) in the cytosol decreased only slowly. Despite the marked decrease in classic GPx activity, the lipid peroxide level in the liver did not change until 6 weeks after the start of the feeding, whereas the level was significantly increased by 9 weeks, by which 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.