Endogenous hydrogen sulfide regulates oxidant/antioxidant balance in rat with chronic obstructive pulmonary disease

AIM:To investigate the role of hydrogen sulfide(H2S) in the protection against oxidative stress in rats with chronic obstructive pulmonary disease(COPD).METHODS: The rat model of COPD was established by cigarette smoking(CS) combined with lipopolysaccharide(LPS) instillation.Thirty-two healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group,CS+LPS group,CS+LPS+NaHS(H2S donor) group and CS+LPS+PPG(DL-propargylglycine,an inhibitor of cystathionine-γ-lyase) group.After 30 days,the lung functions of the rats were measured,the histological changes of lungs were observed under light microscope and the pathological scores were calculated.The H2S level in plasma and the protein expression of cystathionine-γ-lyase(CSE) in the lung tissues were measured.The content of malondialdehyde(MDA),the activity of superoxide dismutase(SOD) and catalase(CAT) were detected to reflect oxidative stress.RESULTS: Compared with control group,the peak expiratory flow(PEF) decreased by 24% and intra-pressure(IP) increased by 66% in CS+LPS group.The pathological scores of the lung tissues also increased.Compared with CS+LPS group,no change in the lung function was observed after given NaHS or PPG,but the pathological scores decreased in CS+ LPS+ NaHS group.Compared with control group,the content of H2S in plasma was increased by 26% on day 16.Compared with CS+LPS group,the content of H2S in plasma of CS+LPS+PPG group was decreased by 22% after 30 days.Compared with control group,the protein expression of CSE increased,and no statistical difference among CS+LPS group,CS+ LPS+ NaHS group and CS+LPS+PPG group was observed.Compared with control group, MDA content in the lung tissues was increased by 24% in CS+LPS group,the activity of SOD was increased by 47% and the activity of CAT was increased by 52%.Compared with CS+LPS group,the MDA content in CS+LPS+NaHS group was decreased by 21%,and no statistical difference in the activity of SOD and CAT was observed.The activity of SOD decreased by 33% after given PPG.CONCLUSION: H2S plays a role as anti-oxidant in the rats with COPD.The CSE/ H2S pathway may be involved in the development of COPD.