Abstract

Background. Short time pretreatment with oxygen is reported to be protective against subsequent ischemia-reperfusion (IR) injury of heart and spinal cord in some animal models. The purpose of this study was to investigate the effects of pre-exposure to hyperoxic environment on rat renal IR injury for the first time. Materials and methods. The effects of 1 h/d pretreatment with oxygen (>= 95) for 5 days on a right nephrectomized rat model of renal IR injury was investigated by comparing creatinine clearance, fractional excretion of sodium, plasma creatinine, blood urea nitrogen, and histological injury scores among three groups: IR (40 min ischemia-24 h reperfusion), sham (no IR), and hyperoxia (5 days intermittent pretreatment with oxygen + IR). Results. Intermittent pretreatment with oxygen resulted in significant improvement of creatine clearance and fractional excretion of sodium (P <= 0.05). Plasma creatinine above 175 mu mol/L or blood urea nitrogen beyond 26 mmol/L was significantly less frequent in hyperoxia than IR group (P < 0.05). Jablonski histological injury score was also significantly lower in hyperoxia compared to IR group (P < 0.05) and hyperoxic preconditioning significantly reduced the frequency of massive proximal tubular necrosis (12.5 versus 75, P < 0.05). Conclusions. The present findings demonstrate that intermittent pre-exposure to hyperoxic environment can reduce subsequent renal IR injury. (c) 2008 Elsevier Inc. All rights reserved.