Hydrogen Sulfide Antagonizes Oxidative Stress,Apoptosis,and Neurogenesis Impairment In Hippocampus Of Postoperative Aged Rats

[Background and Objective]Surgical stress can affect the physiological function of the body,which can increase the level of oxidative stress and apoptosis and reduce the ability of neurogenesis in hippocampus.Hydrogen sulfide（H₂S）has neuroprotective effects in central nervous system.Therefore,this study was designed to investigate the effects of hydrogen sulfide on oxidative stress,apoptosis,and neurogenesis in the hippocampus of postoperative aged rats.[Methods]Sprague-Dawley（SD）rats were anesthetized with isoflurane and then the rats were administrated to laparotomy.After laparotomy,enzyme linked immunosorbent assay（ELISA）were used to detected the content of malondialdehyde（MDA）,4-hydroxynonenal（4-HNE）,and L-glutathione（GSH）in hippocampus,nitrotetrazolium blue chloride（NBT）was used to detect the content of superoxide dismutase（SOD）in hippocampus,tunel staining was used to detect the apoptosis of hippocampal cells,western blot analysis was used to detect the expressions of Bcl-2,Bax,Cleaved caspase-3 and Synapsin-1 in hippocampus,immunohistochemistry（IHC）was used to check out the expression of MCM2,DCX,and Synapsin-1 in hippocampus,and immunofluorescence（IF）was used to detect the number of NeuN⁺/BrdU⁺positive cells and GFAP⁺/BrdU⁺positive cells in hippocampus.[Results]1.H₂S inhibited oxidative stress in the hippocampus of postoperative aged rats.（1）NaHS（100μmol/kg,i.p.for 14 d）significantly reduced the content of MDA and 4-HNE,increased the level of GSH,and raised the activity of SOD in the hippocamus of postoperative aged rats.These results indicated that H₂S antagonize hippocampal oxidative stress in the postoperative aged rats.2.H₂S inhibited the apoptosis of hippocampus in postoperative aged rats.（1）NaHS（100μmol/kg,i.p.for 14 d）significantly reduced the number of the tunel positive cells in hippocampus.（2）NaHS（100μmol/kg,i.p.for 14 d）increased the expression of Bcl-2 protein and reduced the expression of Bax and Cleaved caspase-3 protein.These results suggested that H₂S antagonize the apoptosis of hippocampus in postoperative aged rats.3.H₂S improved the ability of neurogenesis in postoperative aged rats.NaHS（100μmol/kg,i.p.for 14 d）raised the expression of MCM2 and DCX,increased the proportion of NeuN⁺/BrdU⁺positive cells in the DG area,and raised the expression of Synapsin-1 in the hippocampus of postoperative aged rats,which indicated that H₂S ameliorate the neurogenesis in the hippocampus of postoperative aged rats.[Conclusion]Hydrogen sulfide can inhibit oxidative stress and apoptosis as well as can improve the neurogenesis in postoperative aged rats.