大鼠局灶性脑缺血后神经营养因子表达的自然变化

目的 观察大鼠局灶性脑缺血后大鼠神经行为、梗死体积、组织形态及缺血半暗带神经生长因子(NGF)、脑源性神经营养因子(BDNF)的表达水平变化。方法 将健康雄性SD大鼠24只随机分为2组,Ⅰ组(假手术组); Ⅱ组(脑缺血组)。用线栓法建立动物模型,不给予再灌注,各组在术后48h断头取脑,处死前行神经功能评分,用氯化三苯基四氮唑(TTC)染色计算脑梗死体积,用HE染色观察组织学形态,用免疫组织化学染色观察NGF、BDNF的表达水平。结果 Ⅰ组在神经功能评分、梗死体积、组织形态及大脑皮层相应部位NGF、BDNF阳性细胞数均正常。与Ⅰ组比较,Ⅱ组的神经功能评分和梗死体积均严重受损; 光镜下Ⅱ组缺血性病理改变较重,与Ⅰ组比较,Ⅱ组缺血半暗带NGF、BDNF阳性神经元数增加(P<0.05)。结论 脑缺血本身可上调缺血半暗带NGF、BDNF的表达水平。

Expression of neurotropic factors after focal cerebral ischemia injury in rats.

ObjectiveTo observe the expression of neurotropic factors on a rat model of focal middle cerebral artery occlusion(MCAO).Methods Twenty-four male Sprague-Dawley rats were randomly divided into two groups, groupⅠ(Sham operated rats)and groupⅡ(MCAO ischemia). The neuroethology assessment was evaluated at 48h before the rats were executed and given reperfusion. The volume of cerebral infarction and the pathologic changes were observed by TTC staining and HE staining. The expression of NGF and BDNF was tested by immunohistochemistry.Results Under optical microscope, group Ⅱhad more degree of cerebral ischemic injury in pathomorphology. The numbers of NGF and BDNF immunopositive neurons in ischemic penumbra of groupⅡ were higher than those in cerebral cortex of groupⅠ(P <0.05).Conclusions Brain ischemia injury can increase the expression NGF and BDNF in the brain ischemic penumbra, bur its mechanism is not clear.