七氟醚对老年大鼠术后认知功能及海马miR-132表达的影响

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(1 424±198)、(1 052±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.

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

Objective To investigate the effects of sevoflurane on postoperative cognitive function and hippocampus miR132 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 02.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 h,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 d 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 hippocampus 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.