The Apoptosis Of Neuron And Its Relation To The Expression Of Caspase-9 MRNA After Focal Cererral Ischemia Reperfusion In Rats

Objective: To study apoptosis and the expression of caspase-9 mRNA of neuronal cells after focal cerebral ischemia/reperfusion in rats. Methods: Nylpon thread was inserted into the middle cerebral artery in rat to produce an animal model of focal cerebral ischemia/reperfUsion (MCAO). Coronal sections of brain were analyzed using toluidine blue ( TB ) staining, transmission electromicroscopy (TEM) and mrthyl green-pyronin ( MGP ) staining methods after reperfusion (2,6,12, 24hours and 2,3,7,14days) of focal cerebral ischemia in rats. The Caspase-9 mRNA was detected in situ hybridization after ischemia reperfusion. Results: (1) According to the TB staining, the MGP staining and the TEM observation, there were characteristic apoptosis in the ischemic penumbra and there were more number of necroti neurons in central area than that in ischemic penumbra.(2) The expression of Caspase-9 mRNA began at 2h after reperfusion, peaked at 24h after reperfusion, and then decreased significantly at 14th day. The time-phase pattern of Caspase-9 mRNA is similar to that of apoptosis. Conclusion: Apoptosis is a pattern of neuronal cell death after MCAO. Caspase-9 mRNA could increase in the apoptosis of neuronal cell death, within a certain extent, the expression ofCaspase-9 mRNA was positively related to the degree of apoptosis. The over expression of caspase-9 could play a role in the induction of apoptosis following cerebral ischemia reperfusion in rat.