大鼠持续性脑缺血后小胶质细胞变化及其与神经元凋亡的关系

The relationship between the change of microglia and neuron apoptosis in adult rats following permanent middle cerebral artery occlusion

目的 研究成年大鼠持续性局灶脑缺血后小胶质细胞的变化及其与缺血后凋亡的关系。方法 采用单侧大脑中动脉近端电凝术建立成年大鼠持续性局灶脑缺血模型。在手术后 3 h、6h、1 2 h、2 4 h、4 8h、72 h和 1 2 0 h取材 ,分别用 Isolectin B4凝集素标记小胶质细胞和原位末端 TUNEL法标记凋亡细胞。结果 缺血后凝集素阳性小胶质细胞和 TUNEL阳性小胶质细胞都分布在梗死灶周边区。缺血 1 2 h在梗死灶的边缘密集分布凝集素标记阳性细胞 ,2 4～ 72 h凝集素阳性小胶质细胞数量增加 ( P<0 .0 5) ,1 2 0 h阳性细胞数量减少 ( P<0 .0 1 )。脑缺血 4 8h、72 h、1 2 0 h在梗死灶边缘区域分布 TUNEL阳性凋亡细胞 ,TUNEL阳性细胞以神经细胞为主。结论 持续性局灶脑缺血后活化小胶质细胞主要分布在梗死灶周边区 ,可能对缺血后神经元凋亡产生作用。

Objective To investigate the relationship between the change of microglia and neuron apoptosis in adult rats following permanent middle cerebral artery occlusion(MCA). Methods The rats models of focal cerebral ischemia were established by permanent middle cerebral artery occlusion and brain tissue were collected at different times. The microglia was demonstrated by histochemical staining with isolectin B4. In situ end labeling TUNEL methods were used to study cell apoptosis in brain. Results The apoptosis and the change of microglia were mainly located at the border zone of infarct.The accumulation of the isolectin positive microglia began at 12h,peaked at 2d, decreased at 5d. The TUNEL positive apoptotic cells were present from 48h to 5d.Conclusions The developing infarction is accompanied by accumulation of actived microglia. The change of microglia may play an important role in the neuron apoptosis after focal cerebral ischemia.