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.