c-fos和神经营养因子在大鼠脑缺血再灌流时的神经元表达特点

为了观察脑缺血再灌流时 c-fos和神经营养因子在神经元表达的时空特点 ,探讨其在缺血性神经元损伤中的作用 ,本研究用阻塞 SD大鼠大脑中动脉 2 h、再灌流 0 .5～ 48h制成局灶性脑缺血模型 ,用免疫组化方法观察了 c-fos和神经营养因子转化生长因子、神经生长因子和胶质源性神经营养因子在神经元的表达特点。结果表明 ,c-fos和转化生长因子分布相似 ,正常组无 c-fos和转化生长因子阳性神经元 ;缺血再灌流 0 .5～ 48h阳性的神经元主要位于非大脑中动脉供血区 ,缺血区皮质、纹状体和视前区神经元为阴性。而实验各组对照侧皮质神经元中等阳性。神经生长因子、胶质源性神经营养因子在缺血脑组织的分布相似。正常组、假性手术组 ,皮质、嗅结节、丘脑和下丘脑等区的神经元神经生长因子、胶质源性神经营养因子免疫反应为弱阳性乃至强阳性 ;再灌流 0 .5 h,缺血区皮质弱阳性 ,缺血周边区中等阳性 ;再灌流 3～ 48h,神经生长因子、胶质源性神经营养因子强阳性的神经元主要位于非大脑中动脉供血区和缺血周边区。此外 ,对照侧皮质大量的神经元呈强阳性。结论 ,上述资料提示即早基因 c-fos和神经营养因子具有促进神经元存活的作用

THE EXPRESSIVE CHARACTERISTICS OF NEURON OF IMMEDIATELY EARLY GENE c-fos AND NEUROTROPHIC FACTORS TGF-

To study the temporal and spatial pattern of distribution of immediate early gene c-fos and neurotrophic factors TGF-β 1, NGF, GDNF in rat following ischemia-reperfusion. The focal cerebral ischemia was established by occluding middle cerebral artery (MCA)for 2 hours and reperfusing 0.5～48 hours. The immunohistochemical method was used to study c-fos, TGF-β 1, NGF and GDNF expression in neurons. The expressive pattern of c-fos and TGF-β 1 was similar. At 0.5～48 hours of reperfusion, the strongly positive neurons were primarily located in areas not supplied by MCA, neurons in ischemic cortex, striatum, and preoptic area were c-fos and TGF-β 1 negative. In contrast, the neurons of contralateral cortex were stained moderately positive. The expressive pattern of NGF and GDNF was similar. In normal group and sham operated group, the neurons of the cortex, olfactory tubercle, thalamus and hypothalamus et al. expressed NGF and GDNF and were stained from weakly to strongly positive. At 0.5 hour of reperfusion, neurons in ischemic cortex were stained weakly positive, while neurons in peri-ischemic regions showed moderately immunoreaction positive. During 3～48 h, the strongly positive neurons were chiefly located in areas not supplied by MCA and peri-ischemic regions. Furthermore, most of neurons in contralateral cortex were strongly immunoreaction positive. Conclusion, These data suggested that c-fos and neurotrophic factors play a significant role in protecting neurons against ischemic injury. (Figures 1～8 on plate 15)