Effect of hydrogen inhalation on lung ischemia-reperfusion injury in mice

Abstract

Objective To investigate the effect of hydrogen inhalation on lung ischemia-reperfusion (I/R) injury in mice.Methods Fifty male C3H/HeN mice,aged 6-8 weeks,weighing 20-25 g,were randomly divided into 5 groups (n =10 each) using a random number table:sham operation group (group SH),I/R group,1％ H2 group,2％ H2 group and 4％ H2 group.Lung I/R was produced by occlusion of the left hilum of lungs for 60 min followed by 240 min reperfusion.1％,2％ and 4％ H2 were inhaled during reperfusion in 1％ H2,2％ H2 and 4％ H2 groups,respectively.At the end of reperfusion,blood samples were obtained for blood gas analysis.PaO2/FiO2 was calculated.The animals were then sacrificed and lungs were immediately removed for determination of the levels of superoxide dismutase (SOD),malonaldehyde (MDA),tumor necrosis factor-α (TNF-α),interleukin-8 (IL-8),Toll-like receptor 4 (TLR4) and myeloperoxidase (MPO) in the lung tissues and for microscopic examination of the pathological changes of lungs which were scored.Results Compared with SH group,PaO2/FiO2 was significantly decreased,the pathological scores,levels of MDA,TNF-α,IL-8,TLR4 and MPO were increased,and SOD activity was decreased in I/R,1％ H2,2％ H2 and 4％ H2 groups.Compared with group I/R,PaO2/FiO2 was significantly increased,the pathological scores and levels of MDA,TNF-α,IL-8,TLR4 and MPO in lung tissues were decreased,and SOD activity was increased in 1％ H2,2％ H2 and 4％ H2 groups.There were no significant differences in the indices mentioned above among 1％ H2,2％ H2 and 4％ H2 groups.Conclusion Hydrogen inhalation can alleviate lung I/R injury in mice,and the mechanism is related to inhibition of lipid peroxidation responses and inflammatory responses. Key words: Hydrogen ; Reperfusion injury ; Lung