Antineoplastic Agents ; therapeutic use ; Clinical Trials as Topic ; Humans

Objective To evaluate the role of mitochondria-mediated apoptosis in hippocampal neurons in sevoflurane anesthesia-induced cognitive dysfunction in aged rats.Methods Sixty healthy male Sprague-Dawley rats,aged 20 months,weighing 550-600 g,were randomly divided into 2 groups (n =30 each) using a random number table:control group (group C) and sevoflurane anesthesia group (group S).Animals inhaled pure oxygen and 3 ％ sevoflurane for 4 h in C and S groups,respectively.Ten rats were chosen at 1 and 6 days after anesthesia and hippocampal tissues were obtained for detection of cell apoptosis and mitochondrial membrane potential (MMP) (using flow cytometry) and expression of cytochrome c (Cyt c) in cytoplasm and activated caspase-3 in hippocampal neurons (by Western blot).The apoptotic rate was calculated.Results Compared with group C,the escape latency was significantly prolonged,the frequency of crossing the original platform,the percentage of time of staying at the original platform quadrant and MMP were decreased,the apoptotic rate was increased,and the expression of activated caspase-3 and Cyt c in cytoplasm was up-regulated in.group S.Conclusion The mechanism by which sevoflurane anesthesia induces cognitive dysfunction is related to the activation of mitochondria-mediated apoptosis in hippocampal neurons of aged rats.

Objective To evaluate the effect of preconditioning with nimodipine on postoperative cognitive dys function of aged rats.Methods Ninety healthy male Sprague-Dawley rats,aged 18 months,weighing 400-500 g,were randomly divided into 3 groups (n =30 each) using a random number table:nimodipine control group (group N),surgery group (group S),and nimodipine + surgery group (N+ S group).In N and N + S groups,nimodipine 1 mg/kg was intraperitoneally injected,while the equal volume of normal saline was given instead in S group.30 min later,group N inhaled pure oxygen for 2 h,and S and N + S groups inhaled 1.8 ％ isoflourane for 2 h when splenectomy was performed.Morris water maze test was performed on 1 day before operation and 1st,3rd and 7th days after operation.After the end of Morris water maze test at 1 day before operation and 1st and 7th days after operation,10 rats were sacrificed and brains were removed and hippocampi were isolated for determination of apoptosis in hippocampal neurons,intracellular [Ca2+] i in cytoplasm,and hippocampal Bcl-2 and Bax mRNA expression and for examination of ultrastructure of hippocampal neurons.Results Compared with the value before administration,the escape latency was significantly prolonged,the frequency of crossing the original platform was decreased,apoptotic rate and [Ca2+]i were increased,Bcl-2 mRNA expression was down-regulated,and Bax mRNA expression and Bax/Bcl-2 mRNA ratio were up-regulated at each time point after operation in S and N + S groups,and no significant changes were found in the parameters mentioned above in N group.Compared with group S,the escape latency was significantly shortened,the frequency of crossing the original platform was inecreased,apoptotic rate and [Ca2+]i were decreased,Bcl-2 mRNA expression was up-regulated,and Bax mRNA expression was down-regulated at each time point after operation in group N + S.Pathological changes were found in S and N + S groups and the damage was severer in S group than in N + S group.Conclusion Nimodepine preconditioning can prevent postoperative cognitive dysfunction of aged rats,and inhibition of calcium overloadinduced apoptosis in hippocampal neurons may be involved in the mechanism.