Dual Gas Treatment With Hydrogen and Carbon Monoxide Attenuates Oxidative Stress and Protects From Renal Ischemia-Reperfusion Injury.

BACKGROUND

Hydrogen (H) and carbon monoxide (CO) gas are both reported to reduce reactive oxygen species and alleviate tissue ischemia-reperfusion (I-R) injury. The present study was conducted to evaluate the effects of a mixture of H gas and CO gas (dual gas) in comparison with hydrogen gas (H: 2%) alone on I-R renal injury (composition of dual gas; N: 77.8%; O: 20.9%; H: 1.30%; CO: 250 parts per million).

METHODS

Adult male Sprague-Dawley rats (body weight 250-280 g) were divided into 5 groups: (1) sham operation control, (2) dual gas inhalation (dual treatment) without I-R treatment, (3) I-R renal injury, (4) H gas alone inhalation (H treatment) with I-R renal injury, and (5) dual treatment with I-R renal injury. I-R renal injury was induced by clamping the left renal artery and vein for 45 minutes followed by reperfusion, and then contralateral nephrectomy was performed 2 weeks later. Renal function was markedly decreased at 24 hours after reperfusion, and thereafter the effects of dual gas were assessed by histologic examination and determination of the superoxide radical, together with functional and molecular analyses.

RESULTS

Pathologic examination of the kidney of I-R rats revealed severe renal damage. Importantly, cytoprotective effects of the dual treatment in comparison with H treatment and I-R renal injury were observed in terms of superoxide radical scavenging activity and histochemical features. Rats given dual treatment and I-R renal injury showed significant decreases in blood urea nitrogen. Increased expression of several inflammatory cytokines (tumor necrosis factor-α, interleukin-6, intracellular adhesion molecule-1, nuclear factor-κB, hypoxia inducible factor-1α, and heme oxygenase-1) was attenuated by the dual treatment.

CONCLUSIONS

Dual gas inhalation decreases oxidative stress and markedly improves I-R-induced renal injury.