大鼠弥漫性轴索损伤后脑干内α7烟碱型乙酰胆碱受体的表达变化

Effect of diffuse axonal injury on expression of α7 nicotinic acetylcholine receptor in the rat brain stem tissues

目的探讨弥漫性轴索损伤(DAI)后大鼠脑干内的烟碱型乙酰胆碱受体α7亚型(α7nAChR)的动态变化。方法 50只SD大鼠按随机数字表随机分为正常组、假损伤组、DAI7d组、DAI30d组和DAI90d组,每组10只。正常组立刻处死,假损伤组麻醉且固定于头夹后处死,DAI7d组、DAI30d组与DAI90d组分别于致伤后7、30与90d后处死。取脑干进行免疫组化染色,检测α7nAChR的表达情况,使用IPP软件对α7nAChR进行定量评估。结果正常组、假损伤组与DAI7d组之间α7nAChR的表达无显著性差异。DAI30d组与正常组、假损伤组、DAI7d组相比,α7nAChR表达水平明显降低(P<0.05);而DAI90d组α7nAChR表达水平又明显低于DAI30d组(P<0.05)。结论 DAI可引起大鼠脑干组织中α7nAChR表达的减少。

Objective To investigate the dynamic changes in the expression of or7 nicotinic acetylcholine receptor （α7 nAChR） in the rat brain stem after diffuse axonal injury （DAI）. Methods Fifty SD rats were randomly divided into three groups, i.e. normal group （n= 10）, sham-injury group （n=10） and DAI group （n=30）. The thirty rats in DAI group were then re-divided into three subgroups, i.e. DAI groups 1 （n=10）, 2 （n=10） and 3 （n=10）, in which the rats were sacrificed 7, 30 and 90 days after DAI respectively. The rats were sacrificed in sham-injury group immediately after they were only subjected to anesthesia and fixation of their head to the head frame. DAI model was made in DAI group. The immunohistochemical technique and the IPP software were used to assess the expression of α7 nAChR in the brain stem tissues of all the rats. Results The levels of α7 nAChR expression in the brain stem tissues was significantly higher in the normal group, sham-injury group and DAI group 1 than that in DAI group 2 （P〈0.05）, which was significantly higher than that in DAI group 3 （P〈0.05）. Conclusion The decrease in the expression of α7 nAChR in rat brain stem tissues may produced by DAI.