大鼠脑挫伤后脑组织β-APP表达与损伤时间的关系

目的观察大鼠实验性脑挫伤后不同时间内脑组织β淀粉样前体蛋白（β-APP）表达的变化,探讨β-APP与脑损伤经过时间的关系。方法参照Feeney’s法建立大鼠脑挫伤模型,在伤后1h,4h,12h,48h,72h,7d,14d,运用免疫组化SABC法和Westernblot法检测β-APP的表达,以非损伤组做对照。结果β-APP出现于损伤后1h,4h开始增加至12h达到高峰,随后阳性反应细胞逐渐减少,7d后仍有少量表达但仍高于对照组,14d后表达基本恢复至接近对照组水平,各实验组与对照组比较有统计学意义（P〈0.05）。结论β-APP在脑挫伤后随时间的变化,其表达呈现先逐渐增加后又减少的一定规律性变化。

An immunohistochemical study on the time-dependent expression of β-APP in cerebral contusion in rats

Objective To investigate dynamic expression of 13-APP at different posttraumatic intervals in the experimental cerebral contusion in rats. Methods The murine model of cerebral contusion was made according to Feeney's method and samples were taken at lh, 4h, 12h, 48h, 72h, 7d and 14d after injury.13-APPwas detected by immunohistochemical SABC procedure and Western blotting. The uninjured rats were used as control. Results Immunoreactivity of β-APP could be detected at 1 h, increased at 4h and peaked at 12h after injury. β-APP-positive cells decreased in number with the prolongation of posttraumatic interval. 13-APP-positive cells were still detectable at 7d post-injury, which was more than those in control in number and resumed to the level of control at 14 d. Conclusion β- APP is time-dependently expressed in a pattern of up-regulation at early phase followed by down-regulation after injury in brain contusion.