Effects of exogenous hydrogen sulfide on nitric oxide and nitric oxide synthase during lung ischemia-reperfusion in a rat model of lung transplantation / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effects of exogenous hydrogen sulfide (H2S) on nitric oxide (NO) and nitric oxide synthase (NOS) during lung ischemia-reperfusion in a rat model of lung transplantation.Methods Forty pathogen-free male Sprague-Dawley rats,weighing 250-350 g,aged 2-3 months,were used as donor and recipient rats in this study.The animals were randomly divided into 4 groups (n =10 each)sham operation group (group S); lung transplantation group (group L); lung transplantation + H2S synthesis-CSE inhibitor D,L-propargylgylcine (PPG) group (group PPG); lung transplantation + exogenous H2S donor NaHS group (group NaHS).The donor lungs were removed from live donor rats and placed in low potassium dextran solution at 4 ℃.Orthotopic left lung transplantation was performed using modified three-cuff technique and the time for cold ischemia was 50-70 min.In PPG and NaHS groups,PPG 37.5 mg/kg and NaHS 14 μmol/kg were injected intraperitoneally at 5 min before opening of the hilum of the transplanted lung.The implanted donor lungs were ventilated and reperfused.The donor lungs were removed after being implanted,ventilated and reperfused for 2 h for microscopic examination and for determination of wet to dry lung weight (W/D) ratio and the levels of malondialdehyde (MDA),myeloperoxidase (MPO),inducible NOS (iNOS),endothelial NOS (eNOS),and NO.Results Compared with group S,W/D ratio and the levels of MDA,iNOS,NO and MPO were significantly increased,and the content of eNOS was decreased in group L,and no significant change was found in the parameters mentioned above in group NaHS.Compared with group L,W/D ratio and the levels of MDA,iNOS,NO and MPO were significantly increased,and the content of eNOS was decreased in group PPG,and W/D ratio and the levels of MDA,iNOS,NO and MPO were decreased,and the content of eNOS was increased in group NaHS.The pathological changes of lungs were significantly attenuated in group NaHS as compared with group L.Conclusion Exogenous H2S can attenuate the lung ischemia-reperfusion injury in a rat model of lung transplantation,and decreased iNOS activity and increased eNOS activity are involved in the mechanism.