Protective effects of hydrogen-rich saline against renal ischemia-reperfusion injury by increased expression of heme oxygenase-1 in aged rats

Objective: Oxygen free radicals (ROS) are considered to be one of the important factors involved in the pathophysiology of aged renal ischemia-reperfusion (I/R) injury. Hydrogen gas has been reported to alleviate I/R injury by scavenging free radicals. The aim of this study was to evaluate the effect of hydrogen-rich saline (HRS) on renal I/R injury in aged rats. Materials and methods: A rat model of renal I/R injury was induced by 45-min occlusion of the bilateral renal pedicles and 24-h reperfusion. Physiological saline or HRS (8 ml/kg) was administered intraperitoneally 5 min before reperfusion. Parameters indicating renal function (blood urea nitrogen (BUN) and serum creatinine (SCr)) and those indicating oxidative stress (tissue levels of malondialdehyde (MDA) and 8-hydroxy- deoxyguanosine (8-OHdG), tissue activities of superoxide dismutase (SOD), and tissue expression of heme oxygenase-1 (HO-1)) were measured. Results: After I/R injury, BUN, SCr, tissue levels of MDA and 8-OHdG, and gene expression of HO-1 were all significantly increased while tissue activities of SOD were significantly decreased. HRS reversed these changes, with the exception of HO-1 expression, which was increased further, and improved renal morphology. Conclusions: HRS improves the renal response to I/R in aged rats, possibly by reducing oxidative stress and upregulating HO-1 gene expression.