EFFECTS OF OZONE OXIDATIVE POSTCONDITIONING ON RENAL TUBULAR EPITHELIAL CELLS AGAINST ISCHEMIA/REPERFUSION INJURY IN RATS.

Ischemia/reperfusion injury is seen in renal surgery or transplantation. It is a major cause of acute renal failure. Since ozone oxidative preconditioning attenuates renal ischemia/reperfusion injury, morphology of tubular epithelial cells was investigated in order to prove that ozone oxidative postconditioning reduces renal ischemia/reperfusion injury. Twenty adult Wistar rats were divided into four groups: control, ischemia/reperfusion damaged (60 min of ischemia, with 10 days of reperfusion), and two groups of rats submitted to ischemia and postconditioned during reperfusion: one group with ozone (0.5 mg/kg body weight) and another one with oxygen (13 mg/kg body weight). Kidneys were fixed in buffered formalin, paraffin-embedded and stained with HE and PAS. Five variables were analyzed in renal proximal tubules in 10 fields per section, by means of a mathematical model designed for this study. Groups were compared taking into account the percentage of damaged proximal tubules per field for each variable by applying the statistical program Graph Pad Prism version 5.00 for Windows. Normal structure was observed in control group. Loss of brush border, discontinuity and denudation of tubular basement membrane, presence of peritubular inflammatory cells and cell necrosis was noticed in ischemia/reperfusion damaged group. Remarkable conservation of proximal tubules was observed in ozone-postconditioned. By contrast, in oxygen-postconditioned group, tubular morphology was similar to ischemia/reperfusion damaged group.