大鼠弥漫性脑损伤后脑组织α-syn的表达

Expression of α-synuclein in brain tissue of rats with diffuse brain injury

目的观察α-突触核蛋白(α-synuclein,α-syn)在大鼠弥漫性脑损伤(diffuse brain injury,DBI)后脑组织中的表达规律。方法采用Marmarou方法制作大鼠DBI模型,将72只SD大鼠随机分为10个DBI组、1个对照组和1个假手术组。用免疫组化技术及图像分析方法观察大鼠DBI后0.5、1、3、6、12、24、48、72、96、168 h和对照组、假手术组脑组织内α-syn表达规律,所得数据经SPSS统计软件分析处理。结果 DBI大鼠大脑皮质、海马、脑干内α-syn阳性细胞个数及平均光密度变化形成先升后降再升的曲线。大脑皮质α-syn阳性细胞个数和平均光密度在损伤后1h少量增加,3 h明显增多,6 h达到高峰。而后逐渐减少,大脑皮质α-syn第2次表达高峰在损伤后96 h出现。海马、脑干部位α-syn阳性细胞个数及平均光密度第1次表达高峰出现于损伤后6 h,第2次表达高峰约在损伤后72 h出现。结论采用免疫组化方法检测脑组织内α-syn可作为DBI诊断的参考指标,同时对推断弥漫性脑损伤时间也有一定的价值。

Objective To observe the expression of α-synuclein in brain tissue of rats with diffuse brain injury（DBI）.Methods The model of rat with diffuse brain injury was established based on Marmarou＇s method.Seventy-two SD rats were randomly divided into 10 groups with diffuse brain injury at 0.5 h,1 h,3 h,6 h,12 h,24 h,48 h,72 h,96 h,168 h after brain injury respectively,1 sham-operated group and 1 control group.Expression of α-synuclein in brain tissue of rats was detected by immunohistochemical staining in combination with imaging analysis.The data were analyzed by using SPSS software.Results The number of cells with positive staining and the concentration of α-synuclein in brain cortex,hippocampus,brainstem in rat with diffuse brain injury increased firstly and followed by a decrease and then a second increase.The expression of α-synuclein in brain cortex increased gradually in 1 h and dramatically after 3 h and then reached the first maximal level at 6 h after brain injury,and the second peak level of α-synuclein expression appeared at 96 h after brain injury.The expression of α-synuclein in hippocampus and brainstem reached the first maximal level at 6 h after brain injury and the second peak level of α-synuclein expression appeared at 72 h after brain injury.Conclusion The immunohistochemical detection of α-synuclein expression in brain tissue may be used as a method for diagnosis of diffuse brain injury and the change of α-synuclein expression may be helpful for dating of diffuse brain injury.