C57black/6小鼠全脑缺血模型脑内Bax和Bcl-2的表达

本研究采用C57black/6小鼠制备全脑缺血模型,观察脑缺血后多个脑区Bax和Bcl-2基因的表达。双侧颈总动脉夹闭(bilateral common carotid artery occlusion,BCCAO)15min,造成全脑缺血,24h后取脑组织进行Bax和Bcl-2免疫组织化学染色。结果显示:Bax阳性细胞广泛分布在大脑皮层、丘脑和杏仁核,阳性产物主要位于胞质内。除丘脑外,其他各部位Bax阳性神经元的密度缺血组均显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。Bcl-2阳性细胞在大脑皮层和丘脑均有表达,缺血组大脑皮层内Bcl-2阳性神经元的密度显著高于假手术组(P<0.05);缺血组各区域细胞染色灰度值均显著低于假手术组(P<0.01)。以上结果表明双侧颈总动脉夹闭法致C57black/6小鼠全脑缺血模型可致多脑区Bax和Bcl-2的广泛表达,提示Bax和Bcl-2可能介导了缺血所致的神经元损伤。

THE EXPRESSION OF BAX AND BCL-2 IN C57BLACK/6 MICE BRAIN AFTER GLOBAL CEREBRAL ISCHEMIA

The global cerebral ischemia model of C57black/6 mice was used to investigate the!expressions of Bax and Bcl-2 in brain. C57black/6 mice were subjected to 15 minutes occlusion of bilateral common carotid artery. Bax and Bcl-2 immunohistochemical staining of brain tissue was performed 24 hours after ischemia. The results showed that Bax-positive neurons were distributed in cerebral cortex, thalamus and amygdaloid nucleus and the cytoplasm was stained. The density of Bax-positive neurons in the ischemia group was obviously higher than in the sham-surgery group (P<0.05) for all observed areas except thalamus. And the gray values of Bax-positive neurons were more lower in the ischemia group for all areas than in the sham-surgery group(P<0.01) . Bcl-2-positive neurons were distributed in cerebral cortex and thalamus areas. The density of Bcl-2-positive neurons in the ischemia group was significant higher than in the sham-surgery group (P<0.05) for cerebral cortex, while the gray values of Bcl-2-positive neurons were more lower in the ischemia group (P<0.01) for both areas than in the sham-surgery group. These results suggest that C57black/6 mice model of global ischemia can induce extensive expression of Bax and Bcl-2 in brain. Bcl-2 and Bax might mediate the neuronal death after the global ischemia.