Preconditioning with Hyperbaric Oxygen Induces Tolerance Against Renal Ischemia-Reperfusion Injury Via Increased Expression of Heme Oxygenase-1

Objective. Renal ischemia/reperfusion (I/R) injury occurs in both native and transplanted kidneys. Hyperbaric oxygen (HBO) has been shown to prevent I/R injury in different tissues. The aim of this study was to evaluate the effect of HBO on renal I/R injury in rats. Materials and methods. Male Sprague-Dawley rats were randomly assigned to three groups. The sham group (n = 8) received right nephrectomy. The I/R (n = 8) and HBO + I/R groups (n = 8) received 45 min left renal ischemia followed by 24 h of reperfusion after right nephrectomy. The HBO D I/R group (n = 8) received 100% oxygen at 2.5 atmosphere absolute (ATA), for 1 h at every 12 h interval for 2 d. Reperfusion was performed 24 h later after the last HBO exposure. Results. In HBO D I/R group, blood urea nitrogen (BUN) and creatinine levels decreased significantly compared with the sham and I/R groups (P < 0.01). Activities of superoxide dismutase (SOD) were increased in renal tissue in the HBO + I/R groups. The content of malondialdehyde (MDA) were decreased in the HBO + I/R groups. Kidney samples from HBO + I/R group rats revealed markedly reduced histological damage under histopathological examination. The animals treated with HBO showed significantly elevated heme oxygenase-1 (HO-1) protein and mRNA levels expression compared with I/R group (P < 0.05). Conclusions. Hyperbaric oxygen preconditioning (HBO-PC) can protect renal I/R injury against oxidative stress, and the up-regulation of HO-1 expression plays an essential role in HBO induced preconditioning effect. (C) 2011 Elsevier Inc. All rights reserved.