摘要
目的探讨大鼠脑损伤后胰岛素样生长因子-1(IGF-1)和Bcl-2的表达规律,为脑损伤的法医学研究提供理论依据。方法参照Feeney法建立大鼠脑挫伤模型,通过组织学[苏木素-伊红(HE)染色]和免疫组织化学、蛋白印迹法对正常及伤后不同时间(6,12,24,36,48和72h)大鼠脑组织内IGF-1,Bcl-2蛋白的表达进行检测。结果正常大鼠脑组织内有低水平的IGF-1和Bcl-2表达,损伤后IGF-1表达即呈持续升高趋势,IGF-1免疫阳性细胞以神经元和胶质细胞为主。Bcl-2在伤后的表达呈现双峰现象,即伤后Bcl-2表达即开始升高,于伤后24h时达到峰值,此后开始下降,48h时又开始升高,72h时又达高峰,并较前一峰高,Bcl-2免疫阳性细胞也以神经元和胶质细胞为主。各实验组与对照组比较差异有统计学意义(P<0.05)。结论脑损伤后IGF-1和Bcl-2基因表达开始升高,呈时间依赖性,可以作为法医学损伤时间推断的生物学指标,并可协同发挥神经元保护作用。
Objective To investigate the expression of insulin-like growth factor-1 （IGF-1）and Bcl-2 in brain tissue after experimental cerebral contusion in rats. Methods An experimental rat model of severe cerebral contusion was used and the expressions of IGF-land Bcl-2 proteins at different post cerebral contusion intervals were studied with immunohistochemistry and Western-blot assay. Results Weak expression of IGF-1 and Bcl-2 can be detected in the brain tissue of rats in normal control groups. The level of IGF-1 began to elevate gradually after injury and reached a peak at 72 h post-injury（results of wsstern-blot）, the IGF-1 positive cells were mainly neurons and gliocytes （results of immunohistochemistry）. Bcl-2 was expressed at early phase after injury, and two expressing peaks were found at 24 h and 72 h post-injury（results of Western-blot）, and the Bcl-2 positive cells were mainly neurons and gliocytes（results of immunohistochemistry）, too. The expression patterns of IGF-1 and Bcl-2 in the experimental group were significantly different from that in normal control group （P^0.05）. Conclu- sion The results suggested that injury can stimulate the IGF-1 and Bcl-2 gene expression in neurons. IGF-1 and Bcl-2 may be the important factors influencing the pathological processes and apoptosis after cerebral contusion.
基金
山西省科技厅科技攻关项目(2007031089-1)
