七氟醚预处理对PTSD大鼠行为学及海马Akt-mTOR信号通路的影响

Effects of sevoflurane pretreatment on behavior and Akt-mTOR signal path in rats with PTSDSUN Qian,

目的探讨七氟醚预处理对创伤后应激障碍(PTSD)大鼠行为学及海马Akt-mTOR信号通路的影响。方法将雄性SD大鼠108只,随机分为:正常对照组(C组,n=10),侧脑室置管组(T组,n=10),PTSD模型组(P组,n=22),七氟醚组(S组,n=22),胰岛素生长因子-1组(I组,n=22)和胰岛素生长因子-1联合七氟醚组(IS组,n=22)。采用单一连续应激(SPS)方案建立PTSD大鼠模型。T组侧脑室注射生理盐水5μl;P组侧脑室注射生理盐水5μl后,SPS造模;S组侧脑室注射生理盐水5μl后,吸入七氟醚2h,然后SPS造模;I组侧脑室注射胰岛素生长因子-15μl(0.4μg/μl)后,SPS造模;IS组侧脑室注射胰岛素生长因子-15μl(0.4μg/μl)后,吸入2%七氟醚2h,然后SPS造模。在造模成功后30min、1、2和4h,每组取4只大鼠处死提取海马组织,WesternBlot检测海马Akt、p-Akt、mTOR、p-mTOR表达量;造模后第7天,每组6只,分别行旷场实验和木僵率测试。结果与C组和T组比较,P组、S组、I组和IS组中央格停留时间明显缩短、直立次数明显减少、木僵率、造模后1hp-Akt/Akt和p-mTOR/mTOR表达量明显升高(P<0.05)。与P组和I组比较,S组和IS组中央格停留时间明显延长、直立次数明显增加、木僵率明显降低(P<0.05)。与P组比较,S组造模后1hp-Akt/Akt和p-mTOR/mTOR表达量明显降低(P<0.05);而I组和IS组p-Akt/Akt和p-mTOR/mTOR表达量明显升高(P<0.05)。与I组比较,IS组木僵率、造模后1hS组、IS组p-Akt/Akt和p-mTOR/mTOR表达量明显降低(P<0.05)。与造模后30min比较,造模后1hP组的p-Akt/Akt和p-mTOR/mTOR表达量明显升高(P<0.05)。结论七氟醚可以改善PTSD模型大鼠术后7d的焦虑水平和木僵行为,其效应可能与其抑制PTSD大鼠海马Akt和mTOR的磷酸化有关。

Objective To investigate behavior changes and potential molecule mechanism in posttraumatic stress disorder（PTSD） rats pretreated by sevoflurane. Methods One hundred and eight Male Sprague-Dawley rats were divided randomly into six groups： normal control group（group C,n= 10） ,Cerebroventricular tube group （ group T, n = 10）, PTSD model group （ group P, n = 22）, sevoflurane group（group S,n=22）, insulin-like growth factors-1 group（group I,n=22）, insulin-like growth factors-1 connects sevoflurane group（group IS,n= 22）. We established PTSD rats model by single prolonged stress. In group T, 5 μl saline was given through the cerebroventricular tube; in group P, PTSD model was established by SPS after 5 bd saline was given through the cerebroventricular tube; In group S, after given 5 μl saline by the eerebroventrieular tube, PTSD model by SPS was established after 2% sevoflurane inhalation for 2 h; in I group, PTSD model was established by SPS after 5 μ1（0.4 μg/μl） insulin-like growth factors-1 was given through the cerebroventricular tube; in group IS, after given 5 μl（0.4 μg/μl） insulin-like growth factors-1 by the cerebroventricular tube, PTSD model by SPS was established aher 2%sevo{lurane inhalation was given for 2 h. Four rats in each group were randomly killed in 30 min, 1,2,4 h after PTSD model was establisded and their hippocampal tissues were taken for western blot for testing the expression levelsof Akt, p-Akt, mTOR and p-mTOR. On the 7th day after PTSD model was established, each group （n = 6） received open-field test and freezing behavior test. Results As compared with group C and group T, group P, group S, group I and group IS shoued significant decrease of the detention time in central grille and erect quantity, but showed significant increase of the freezing rate and the expression of p-Akt/Akt and p-mTOR/mTOR at 1 h after PTSD rots model was estabnbbished（P〈0. 05）. As compared with group P and group I, group S and group IS shoued significant increase of the detention time in central grille and erect quantity, but showed significant decrease of the freezing rate（P〈 0.05）. As compared of with group P, group S shoued significant decrease of the freezing rate and the expression of p-Akt/Akt and p-mTOR/mTOR at 1 h after PTSD rots model was estabnbbished（P〈 0. 05） but group I and group IS shoued significant increase of the expression of p-Akt/Akt and p-mTOR/mTOR（P〈0.05）. As compared with group I, the freezing rate of group IS and the expression of p-Akt/Akt and p-mTOR/mTOR at 1 h after PTSD rots model was estabnbbished of group S and group IS all showed significant decrease（P〈0.05）. As compared with 30 min after PTSD rots model was estabnbbished, the expression of p-Akt and p-mTOR at 1 h of group P showed significant increase（P〈0. 05）. Conclusion Sevoflurane can improve anxiety and freezing behavior at the 7th day after PTSD rats model was established and the mechanism of which may associate with p-Akt and p-mTOR expression level in hippocampus of the PTSD rats.