Hydrogen Sulfide Ameliorates The Defects In Hippocampal Autophagy In Postoperative Aged Rats

Objective:To observe the effects of anesthesia and surgery on autophagy in hippocampus of aged rats and conclude isoflurane inhalation can damage the hippocampus of rats after laparotomy,Decrease autophagy level,And after through the administration of exogenous H₂S,the effect on impaired autophagy in hippocampus of aged rats after operation,with autophagy as a starting point,to provide new ideas for the prevention and treatment of POCD.Methods:Selecting 75 healthy clean 18-20 month old Sprague Dawley（SD）male rats were randomly divided into 5 groups（15/group）and control group（PBS）,operation group（Surgery+PBS）,low concentration of H₂S group（Surgery+NaHS 30 mol/kg）,high concentration H₂S group（Surgery+Na HS 100 mol/kg）.Before laparotomy,the low dose NaHS treatment and high dose NaHS treatment group and the simple NaHS treatment group,were treated with different concentrations of NaHS by intraperitoneal injection for 14 days.Control group and simple operation group intraperitoneal injection of PBS consecutively for 14days;At 3 days after operation,all the brain tissues of rats were survived,a number of autophagic bodies in CA1 area of hippocampus was observed by transmission electron microscope,Western-Blot method was used to detect the expression of LC3,Beclin1 and P62 in the hippocampal CA1 area of rats.Results:1.The disorder of CA1 in hippocampus of aged rats.1.1 The CA1area of hippocampus in aged rats was observed by transmission electron microscope.The results showed that the number of autophagic bodies and the number of autophagic lysosome in the CA1 area of hippocampus in the rats in the operation group was significantly lower than that in the control group.1.2 The expression of autophagy related protein LC3 in the hippocampal CA1 area of aged rats was decreased three days after laparotomy.1.3 The expression of autophagy related protein Beclin1 in the hippocampal CA1 area of aged rats was decreased three days after laparotomy.1.4 The expression of autophagy related protein CA1 in the hippocampus of P62 rats aged three days after laparotomy.2.H₂S can improve the dysfunction of hippocampus CA1 area in aged rats.2.1NaHS（30,100 mol/kg/d）was pretreated by for the first time on the first day of the laparotomy.The results showed that H₂S could improve the dysfunction of CA1 in the hippocampus of aged rats after operation.2.2NaHS（30,100 mol/kg/d）was pretreated for 14 days before laparotomy,and it was found that H₂S could promote the expression of CA1 in hippocampus of aged rats.2.3 NaHS（30,100 mol/kg/d）was pretreated for 14 days before laparotomy,and H₂S was found to up regulate the expression of CA1 in hippocampus of aged rats.2.4 NaHS（30,100mol/kg/d）was pretreated for 14 days before laparotomy,and H₂S was found to down regulate the expression of CA1 in the hippocampus of aged rats.Conclusion:1.The autophagy in hippocampus of postoperative aged rats is defected.2.H₂S ameliorates the impairement of autophagy in the hippocampus of postoperative aged rats.