Impact of hydrogen sulfide on oxidative damage in lung of rats after ischemia-reperfusion

Objective To explore the impact of hydrogen sulfide(H2S) on oxidative damage in lung of rats after ischemia-reperfusion.Methods We used sodium hydrosulfide(NaHS) as the donor of H2S.Fifty SD rats were randomly divided into sham group(n=10),lung ischemia-reperfusion group(IR group,n=10) and IR+NaHS group,and the IR+NaHS group was divided into IR+NaHS 10μmol·kg-1 group(n=10),IR+NaHS 20 μmol·kg-1 group(n=10),IR+NaHS 30μmol·kg-1 group(n=10).Five days before the experiment,rats of IR+NaHS(10μmol·kg-1,20μmol·kg-1and 30μmol·kg-1) groups were pretreated(intraperitoneal injection) with different dose of NaHS according to the weight,and administration again 15 min before the experiment;sham group and IR group were pretreated(intraperitoneal injection) with normal saline(1ml·kg-1).An rat lung I/R model was built in vivo.At the end of the experiment,all rats were put to death after blood was collected from left atrium.We examined indices of lung injury:lung histological change,ratio of lung wet weight to dry weight (W/D),malondialdehyde(MDA) and myeloperoxidase(MPO) content,activities of superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in lung tissues.Results The W/D ratio of lung tissue,contents of MDA and MPO in lung tissue in the IR group and IR+NaHS groups were significantly higher than those in the sham group (P0.05 or P0.01),while the indices above in IR+NaHS groups were significantly lower than those in the IR group(P0.05);The activities of SOD and GSH-Px in lung tissue in the IR group and IR+NaHS groups were significantly lower than those in the sham group (P0.05 or P0.01),while the indices above in IR+NaHS groups were significantly higher than those in the IR group(P0.05 or P0.01).All the indices abovementioned had no statistical significance in three dose of IR+NaHS groups.The lung histological change also showed that pre-administration of NaHS could relieve lung ischemia-reperfusion injury.Conclusions These findings suggest that H2S has a certain ability of anti-oxidative damage in lung of rats after ischemia-reperfusion.Its mechanism involves oxyradical elimination and increase the endogenous antioxidant enzyme activity.