七氟醚对老年大鼠术后认知功能及海马miR-132表达的影响

Effects of sevoflurane on postoperative cognitive function and hippocampus miR-132 in aged rats

目的探讨七氟醚对老年大鼠认知功能及海马miR-132表达的影响。方法雄性SD大鼠60只，18-20月龄，行水迷宫训练5d后，按随机数字表法分为对照组（C组）和七氟醚组（S组），每组30只。S组2％七氟醚，C组纯氧处理后6h、1d、3d、7d进行水迷宫实验，记录逃避潜伏期和游泳总距离。各时点水迷宫实验结束后处死大鼠取海马组织，采用实时定量聚合酶链反应检测海马组织内miR-132的表达。结果与C组比较，S组麻醉后6h、1d、3d、7d水迷宫测试的逃避潜伏期及游泳总距离明显延长，海马miR-132表达（0．41±0．03、0．43±0．04、0．51±0．03、0．62±0．05）明显降低（P〈0．05）。S组内，与麻醉后6h比较，麻醉后1d及以后时间点水迷宫测试的逃避潜伏期[（69±10）、（61±11）、（43±9）s]明显缩短（P〈0．05）；麻醉后3、7d水迷宫测试的游泳总距离[（1424±198）、（1052±134）cm]明显缩短（P〈0．05），海马miR-132的表达明显增加（P〈0．05）。S组内，麻醉后7d与麻醉后各时间点比较，水迷宫测试的逃避潜伏期及游泳总距离明显缩短（P〈0．05），海马miR-132的表达明显增加（P〈0．05）。结论七氟醚可导致老龄大鼠术后认知功能障碍，其机制可能与其抑制海马组织内miR-132表达有关。

Objective To investigate the effects of sevoflurane on postoperative cognitive function and hippocampus miR- 132 expression in aged rats. Methods Sixty 18-20 months aged male SD rats,after 5 d＇ training of Morris water maze, were randomly divided into 2 groups （n=30）,normal control group （group C） and sevoflurane group （group S）. In group S, rats were under 2 % sevoflurane anesthesia for 6 h, once a day for 7 d, while group C was kept in the same anesthesia box for 6 h breathing 1 L/min O2. Morris water maze tests were performed on postanesthesia 6 h, 1, 3 d and 7 d. The escape latency and swimming distance were recorded. After water maze test of each test time point,rats were sacrificed and hippocampus were harvested. Changes of miR-132 expression were analyzed by quantitative real-time polymerase chain reaction （qRT-PCR）. Results Compared with group C,the escape latency was prolonged, swimming distance of the water maze test was extended, and the expression of hippocampus miR-132 were decreased on postanesthesia 6 b, 1 d, 3 d, 7 d （0.41±0.03, 0.43±0.04, 0.51±0.03, 0.62±0.05） in group S （P〈0.05）. In group S, compared to postanesthesia 6 h, the escape latency of the water maze test was shortened on postanesthesia 1 （t and after days[（69±10）, （61 ± 11）, （43±9） s]（P〈0.05）. The swimming distance of the water maze test[（ 1 424± 198 ）, （1 052± 134 ） cm] was shortened and the expression of hippoeampus miR-132 was increased on postanesthesia 3, 7 d （P〈0.05）. Compared with each time point after anesthesia, the escape latency and swimming distance of the water maze test were extended （P〈0.05）, and miR-132 expression of hippocampus was increased on postanesthesia 7 d in S group. Conclusions Sevoflurane impair cognitive function in aged rats,the mechanism may relate with the decrease expression of miR-132 in hippocampus.