大鼠脑缺血再灌流后神经细胞凋亡与caspase-3和caspase-9基因表达

目的：探讨大鼠局灶性脑缺血再灌流后神经细胞凋亡及其与caspase-3和caspase-9基因表达的关系。方法：应用原位末端标记和原位杂交技术分别观察细胞凋亡与caspase-3mRNA和caspase-9mRNA表达。结果：脑缺血再灌流后,凋亡神经细胞主要分布于缺血半影区,随着时间的延长凋亡细胞数逐渐增加,至24h达高峰。在缺血半影区,再灌流后神经细胞caspase-3mRNA和caspase-9mRNA表达逐渐增强,到24h阳性细胞数目最多,COD值最高,而缺血中心区两基因均弱表达。结论：脑缺血再灌流后神经细胞凋亡是一个动态的渐进过程。caspase-3和caspase-9基因表达在介导细胞凋亡过程中起重要作用。

Neuron apoptosis and gene expression of caspase-3 and caspase-9 after cerebral ischemia reperfusion in rats

Objective : To study the relationship between neuron apoptosis with expression of caspase-3 and caspase-9 genes after reperfusion of focal cerebral ischemia reperfusion in rats. Methods : The apoptosis of neurons were observed with an terminal deoxynucleotidyl tranferase mediated dUTP-flourescein nick end-labeling(TUNEL) assay. The expression of caspase-3 mRNA and caspase-9 mRNA were determined by in situ hybridization. Results : TUNEL-positive cells were mainly located in ischemic penumbra and progressively increased as time went by and peaked at 24 h after reperfusion. In ischemic penumbra, the expression of caspase-3 mRNA and caspase-9 mRNA in neurons increased from reperfusion 2-6 h and peaked at reperfusion 24 h with most positive cells and highest COD. The above 2 genes expressed weakly in the ischemic central area. Conclusion : Apoptosis of neurons is a dynamic process after cerebral ischemia reperfusion. The activation of caspase-3 and caspase-9 genes play a key role in mediating apoptosis of neurons in cerebral ischemia reperfusion.