Phospholipid hydroperoxide glutathione peroxidase in the normal human kidney: a possible role in protecting cell membranes.

Reactive oxygen species have been implicated in the pathogenesis of tissue injury. It is generally accepted that selenium-glutathione peroxidases form an integrated system defending the living organism against oxidative damage. Phospholipid hydroperoxide glutathione peroxidase (PHGPX) is thought to play a prominent role in preventing lipid peroxidation. Indeed, the function of PHGPX is to reduce the lipophilic substrates in membranes. In the present study, we evaluated the expression of PHGPX in normal human kidney by immunohistochemistry. The enzyme in glomeruli is mainly expressed in podocytes and parietal epithelial cells. In addition, PHGPX antigen was detected in tubule epithelial cells. Therefore, these results suggest that renal epithelial cells possess an important antioxidizing activity related to the presence of PHGPX.