The effect of hydrogen inhalation on shock and resuscitation induced-acute lung injury in rats

Objective To observe the effect of 2% hydrogen on acute lung injury induced by hemorrhagic shock and resuscitation in rats.Methods Twenty-four adult male Sprague-Dawley rats were equally randomized into three groups:sham operation group(group S),shock group(group C) and hydrogen group(group H).Rats in the group C and group H were subjected to 60min of ischemia and 120min of reperfusion to establish pressure-controlled hemorrhagic shock and resuscitation model.The rats in the group S just received intubation and vascular catheter,The rats in the group C received the mixture of 50% nitrogen-50% oxygen throughout the experiment.The rats in the group H inhaled the mixture of 2% hydrogen-48% nitrogen-50% oxygen 10min before reperfusion.The MAP was monitored at six time points:before exsanguinations(T0),15min after exsanguinations(T1),60min after shock(T2),15min after resuscitation(T3),and 60min(T4)and 120min(T5) after reperfusion.Arterial blood samples were collected for blood gas analysis at T0,T2and T5. Blood and lung tissues were collected at the end of experiment.The plasma levels of pro-inflammatory cytokines(IL-6and TNF-α)were determined.Lung tissues were assayed for wet/dry weight ratio(W/D), nuclear transcription factor(NF-κB) p65 expression, and histological changes. Results Compared with T0,PaO2and PaCO2at T2in groups C and H,PaO2at T5in group C, PaCO2at T5in group H were decreased significantly(P0.05).Compared with group S,PaO2and PaCO2at T2in groups C and H,PaO2in group C and PaCO2in group H at T5were decreased significantly(P0.05).Compared with group C,PaO2at T5in group H were increased significantly(P 0.05),there were less infiltration of inflammatory cells,alveolar wall congestion and edema and consolidation of lung tissue.Compared with group C,TNF-αand IL-6,W/D ratio,injury and NF-kBp65 scores were decreased significantly(P0.05).Conclusion 2%hydrogen inhalation can alleviate acutelung injury in rats with hemorrhagic shock and resuscitation.