苯丙胺对小鼠额叶皮质真核翻译延伸因子2的影响

Effect of amphetamine on eukaryotic translation elongation factor 2 in the frontal cortex of mice

目的观察苯丙胺干预后小鼠额叶皮质内真核翻译延伸因子2（eEF2）的表达情况。方法雄性C57BL／6小鼠按随机数字表法分为正常对照组（10只）、生理盐水组（10只）及苯丙胺组（40只），苯丙胺组又分为1、7、14和28d4个亚组，每个亚组10只。苯丙胺组腹腔注射苯丙胺（0．9％生理盐水配置，4℃避光保存12mg／（kg·d），1次／d；生理盐水组注射等量生理盐水；正常对照组不予任何处理。利用空场计算机在线检测系统对各组小鼠进行自主行为活动测试。免疫组化染色及Western blotting检测各组小鼠额叶皮质内eEF2的表达情况。结果（1）苯丙胺7、14、28d组小鼠的运动总路程、平均速度、最大运动速度、快速运动时间／总时间较正常对照组和生理盐水组明显增加，差异有统计学意义（P〈0．05）。（2）免疫组化染色结果显示，与正常对照组和生理盐水组相比，苯丙胺组小鼠eEF2免疫阳性产物灰度值明显降低，差异有统计学意义（P〈0．05）；其中苯丙胺14d亚组、28d亚组较苯丙胺1d亚组、7d亚组免疫阳性产物灰度值进一步降低，差异有统计学意义（P〈0．05）。（3）Western blotting结果显示，苯丙胺组小鼠额叶皮质eEF2蛋白表达量较其他2组明显增强，差异有统计学意义（P〈0．05）；且随时间延长，苯丙胺组小鼠eEF2蛋白表达量进一步增加。结论苯丙胺可引起小鼠额叶皮质eEF2表达显著升高。

Objective To explore the effect of amphetamine on eukaryotic translation elongation factor 2 （eEF2） in the frontal cortex of mice. Methods Male C57BL/6 mice were randomly divided into normal control group （n=10）, saline group （n=10） and amphetamine treatment group （n=40）; the amphetamine treatment group was divided into 1, 7, 14 and 28 d subgroups （n=l 0）. Mice in the amphetamine treatment group were treated with amphetamine 2 mg/（kg, d） via intraperitoneal injection; those in the saline group received a same dose of saline, while those in the normal control group received no treatment. Autonomous behavior activities were tested during establishing amphetamine models. Immunohistochemistry and Western blotting were used to identify the eEF2 expressions. Results Behaviour test showed that total moving distance, average speed, maximum speed, moving fast time/total time in the 7, 14 and 28 d amphetamine treatment subgroups were significantly increased as compared with those in the normal control group and saline group （P〈0.05）. Immumohistoehemical staining indicated that the grey values of eEF2-positive inummoreactive products in the amphetamine treatment group were significantly lower than those in the normal control group and saline group （P〈0.05）; those of eEF2-positive inummoreactive products in 14 and 28 d amphetamine treatment subgroups were significantly lower than those in I and 7 d amphetamine treatment subgroups （P〈0.05）. Western blotting showed that eEF2 protein expression in the frontal cortex was significantly elevated in the amphetamine treatment group as compared with that in the other two groups （P〈0.05）; the eEF2 expression in the amphetamine treatment group increased with time prolonging within 28 days after establishment of models. Conclusion Amphetamine can induce increased eEF2 expression in the frontal cortex of mice.