Hypoxia and reoxygenation-induced injury of renal epithelial cells: effect of free radical scavengers.

The aim of this study was to characterize injuries of LLC-PK1 and MDCK cells exposed to hypoxia and reoxygenation. Exposure of LLC-PK1 cells to hypoxia reduced the ATP contents and increased the leakage of lactate dehydrogenase (LDH), but MDCK cells had no such injuries. Hypoxia-reoxygenation of LLC-PK1 cells dramatically increased LDH leakage, which was suppressed by free radical scavengers, N,N'-diphenyl-p-phenylenediamine, superoxide dismutase and N,N'-dimethylthiourea. These results suggest that use of LLC-PK1 cells has advantages for the investigation of ischemia-reperfusion injury of the kidney as an in vitro model and that generation of oxygen radicals is involved in the cellular injury induced by hypoxia-reoxygenation.