瑞芬太尼预处理对短暂脑缺血后大鼠学习记忆能力的影响

目的观察瑞芬太尼预处理对短暂脑缺血后大鼠学习与记忆能力的影响,并进一步探讨其作用机制。方法♂SD大鼠40只,随机分为假手术(Sham)组、模型(Model)组、瑞芬太尼预处理低剂量(RPC1)、中剂量(RPC2)和高剂量(RPC3)组,每组8只。采用两侧颈总动脉夹闭8min加放血性低血压(30～35mmHg)模型,实现大鼠短暂性全脑缺血,瑞芬太尼预处理分别以0.2、0.6和2μg·kg-1.min-1速率尾静脉泵注5min,停止5min,重复进行3次。再灌注3d后利用Morris水迷宫测量术后大鼠空间学习与记忆的能力,用免疫组织化学法测定大鼠海马CA1区胆碱乙酰转移酶(cho-line acetyltransferase,ChAT)的表达。结果瑞芬太尼中、高剂量组和假手术组大鼠的潜伏期明显短于模型组(P<0.05),在记忆保留实验,瑞芬太尼中、高剂量组和假手术组大鼠的靶象限时间百分比明显高于模型组(P<0.05),而海马CA1区ChAT的表达中剂量、高剂量组也明显高于模型组(P<0.05)。结论瑞芬太尼预处理对短暂脑缺血后大鼠学习与记忆能力有明显改善作用,其作用机制可能与ChAT表达上调有关。

Effects of remifentanil preconditioning on learning and memory in rats with transient cerebral ischemia

Aim To investigate the effects of remifentanil preconditioning on learning and memory in rats after transient cerebral ischemia and evaluate its mechanism. Methods Forty male SD rats were randomly divided into 3 groups:sham group,model group,remifentanil preconditioning(RPC)group with the dose of 0.2 μg·kg-1·min-1 (RPC1 subgroup),0.6 μg·kg-1·min-1 (RPC2 subgroup) or 2.0 μg·kg-1·min-1 (RPC3 subgroup) respectively. Remifentanil was pumped via tail vein for 3 episodes of 5 min at 5 min interval. After 30 min of preconditioning,the 2VO+H ischemia model was finished. All rats were tested with Morris water maze from the third day of reperfusion,then the brains were removed for determination of the expression of ChAT by immunohistochemistry in hippocampus. Results Compared with model group,the latency period in mid dosage group,high dosage group and sham group was significantly reduced (P<0.05) since the third day,while number of times straddling the origin platform and time percentage of straddling the origin platform quadrant and expression of ChAT in mid dosage group,high dosage group and sham group were significantly increased (P<0.05). Conclusion Mid dosage and high dosage remifentanil preconditioning may improve learning and memory via upregulating the expression of ChAT.