Expression Of Brain-derived Neurotrophic Factor After Focal Cerebral Ischemia In Rats

Objectiv:To set up the animal model of the focal cerebral ischemia by occluding middle cerebral artery, and to investigate the expression of brain-derived neurotrophic factor (BDNF) in cortex and hippocampus after focal cerebral ischemia induced by middle cerebral artery occlusion(MCAO).Methods:The SD rats were randomly divided into sham group,ischemia 6h group,ischemia 12h group,ischemia 24h group and ischemia 48h group, every group consisted of six rats. The model of focal cerebral ischemia was set up by blocking the middle cerebral artery(MCA)with filament in rats. The expression of BDNF positive neurons at different time points was observed with the method of immunohistochemistry, RT-PCR and western blot .Results:Comparing with the sham group , there is no significant differences of the expression of BDNF positive neurons in the 6h,12h model groups , while increased remarkably after 24 and 48h modelgroups(P<0.05,P<0.01). Compared 61k 12h model groups with the 241k 48h model groups, the expression of BDNF in the late group increased significantly(P<0.05).Conclusions:The expression of BDNF increased in neurons after focal cerebral ischemia. BDNF may, at least in part, participate in the repairment of injured neurons after focal cerebral ischemia.