七氟烷对小鼠海马PSD-95、NMDA受体及突触结构的影响  

EFFECTS OF SEVOFLURANE ON PSD-95,NMDA RECEPTOR AND SYNAPTIC STRUCTURE OF HIPPOCAMPUS OF MICE

作　　者：任中国 占乐云[1] 舒爱华[1] 覃兆军[1] 陈小波[1] Ren Zhongguo;Zhan Leyun;Shu Aihua(Department of Anesthesiology,People's Hospital of Three Gorges University,Yichang 443000,China)

机构地区：[1]三峡大学人民医院麻醉科,湖北省宜昌市443000

出　　处：《中国煤炭工业医学杂志》2020年第6期595-600,共6页Chinese Journal of Coal Industry Medicine

基　　金：湖北省自然科学基金项目(编号:2018CFB440)。

摘　　要：目的探讨七氟烷(SEV)对小鼠海马突触后密度蛋白-95(PSD-95)、N-甲基-D-天冬氨酸受体(NMDA受体)及突触结构的影响机制。方法取7天龄雄性ICR小鼠幼鼠用2.5%的SEV吸入麻醉诱导建立海马功能损害模型,小鼠56天龄时进行Morris水迷宫测试实验和高架十字迷宫实验,采用激光共聚焦扫描显微镜观察小鼠海马突触结构,采用RT-PCR以及Western blot检测麻醉即刻以及麻醉56天小鼠海马PSD-95、NR1、NR2a、NR2b mRNA和蛋白的表达。结果小鼠Morris水迷宫定位航行实验结果显示,小鼠逃避潜伏期随训练天数增加而缩短(P<0.05),第1天,二组小鼠逃避潜伏期比较差异无统计学意义(P>0.05),第2~4天,SEV组小鼠逃避潜伏期显著长于Ctrl组(P<0.05);小鼠Morris水迷宫空间探索实验结果显示,二组小鼠首次到达平台时间比较差异无统计学意义(P>0.05),SEV组小鼠穿越平台次数显著少于Ctrl组(P<0.05),目标象限停留时间显著短于Ctrl组(P<0.05),二组小鼠游泳速度以及游泳轨迹比较差异无统计学意义(P>0.05);高架十字迷宫行为结果显示,SEV组小鼠进入开放臂时间少于Ctrl组(P<0.05),进入闭合臂次数显著多于Ctrl组(P<0.05),二组小鼠进入开放臂次数以及进入闭合臂时间比较差异无统计学意义(P>0.05);显微镜观察结果显示,SEV组突触密度以及树突棘密度显示少于Ctrl组(P<0.05),突触形成明显受到抑制;麻醉处理即刻,SEV组小鼠海马NMDA受体NR2a、NR2bmRNA和蛋白表达显著高于Ctrl组(P<0.05),PSD-95、NR1mRNA和蛋白表达与Ctrl组比较差异无统计学意义(P>0.05),麻醉处理56天,SEV组小鼠海马PSD-95mRNA和蛋白表达显著低于Ctrl组(P<0.05),NMDA受体NR1、NR2a、NR2b mRNA和蛋白表达与Ctrl组比较差异均无统计学意义(P>0.05)。结论 SEV可对小鼠海马功能造成损害,减少突触密度以及树突棘密度,抑制突触形成,机制可能与下调PSD-95表达以及上调NR2a、NR2b表达有关。Objective To investigate the influencing mechanisms of sevoflurane(SEV) on postsynaptic density protein-95(PSD-95),N-methyl-D-aspartate receptor(NMDA receptor) and synaptic structure of hippocampus of mice.Methods Seven-day-old male ICR young mice were induced with 2.5% SEV inhalation anesthesia to establish models of hippocampus functional damage.The mice at 56 days old were subjected to Morris water maze test and elevated plus-maze test,and laser confocal scan microscopy was used to observe the synaptic structure of hippocampus of mice.RT-PCR and Western blot were used to detect the mRNA and protein expressions of PSD-95,NR1,NR2 a and NR2 b in the hippocampus of mice immediately after anesthesia and at 56 d of anesthesia.Results The results of mice Morris water maze positioning navigation experiment showed that the escape latency of mice was decreased with the increase of training days(P<0.05).On the 1 st d,there was no significant difference in the escape latency between the two groups of mice(P>0.05).On the 2 nd d to 4 th d,the escape latency of SEV group was significantly longer than that of Ctrl group(P<0.05).The results of Morris water maze space exploration experiment showed that there was no significant difference in the time of reaching platform at the first time between the two groups of mice(P>0.05),and the frequency of mice across platform in SEV group was significantly less than that in Ctrl group(P<0.05),and thetarget quadrant stay time was significantly shorter than that in Ctrl group(P<0.05),and there were no significant differences in swimming speed and swimming trajectory between the two groups of mice(P>0.05).The elevated plus-maze behavior results showed that the time of entering open arm in SEV group was less than that in Ctrl group(P<0.05),and the frequency of entering closed arm was significantly more than that in Ctrl group(P<0.05).There were no significant differences in the frequency of open arm and the time of entering closed arm between the two groups(P>0.05).The results of microscopy

关 键 词：七氟烷 突触后密度蛋白-95 N-甲基-D-天冬氨酸受体亚单位1 N-甲基-D-天冬氨酸受体亚单位2a N-甲基-D-天冬氨酸受体亚单位2b 突触结构 

分 类 号：R114[医药卫生—卫生毒理学]