Abstract:

Objective To study the influence of hydrogen sulfide (H2S) on the  mitochondrial function of pulmonary artery smooth muscle cells of the  rats with high pulm
onary blood flow pulmonary hypertension,and to clarify the function and its mechanism in the occurrence of  high pulmonary blood flow pulmonary hypertension.Methods A total of 27 rats were randomly divided sham operation group,operation group,and operation+sodium hydrosulfide (NaHS) group (n=9).The pulmonary hypertension rat model was built by left lung resection.After fed for 35 d,the mean pulmonary artery pressure (mPAP),ratio of right ventricle / body weight (RV / BW),and ratio of right ventricle /(left ventricle+septum) ［RV /(LV + S)］ of the rats in three groups were measured.The plasma H2S levels and the CSE activities in pulmonary artery tissue of the rats were detected;the activities of total mitochondrial ATP enzyme,superoxide dismutase (SOD),glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels were determined;the ultrastructure of pulmonary artery smooth muscle mitochondria was observed through transmission electron microscope.Results  Compared with sham operation group,the plasma H2S level and the CSE activity in p
ulmonary artery tissue of the rats in operation group  were decreased(P<0.01);the mitochondrial membrane of pulmonary tissue was swelling,and the mitochondrial activity was decreased(P<0.01);the mitochondrial ATP enzyme,SOD and GSH-Px activities were significantly decreased,and the MDA level was significantly increased (P<0.01).Compared with operation group,the H2S level in  plasma and the activity of CSE in pulmonary tissue of the rats in operation + NaHS group were increased(P<0.01);the mitochondrial membrane swelling was reduced,and the vitality was restored;the ATP enzyme,GSH-Px,and SOD level in pulmonary tissue were significantly increased (P<0.01),and the MDA level was significantly reduced(P<0.01).Conclusion H2S can enhance the activities of mitochondrial ATP enzyme,GSH-Px,and SOD,and decrease the mitochondrial lipid peroxidation level,thus it plays a protective effect on  rat pulmonary artery smooth muscle.

Key words: hydrogen sulfide, high pulmonary blood flow, pulmonary hypertension, smooth muscle, mitochondria