大鼠脑缺血时凋亡相关基因bc1-2和bax的分布特点

The Distribution of genes related to apoptosis bcl-2 and bax in cerebral ischemia in rats

目的 研究大鼠脑缺血时 bcl- 2和 bax在神经元凋亡中的作用。方法 阻塞大脑中动脉 2 h再灌流0 .5～ 48h制成脑缺血模型 ,免疫组化法观察 bcl- 2和 bax的分布。结果 正常组、皮质神经元的胞膜和突起 bcl- 2阳性 ,纤维束处强阳性。 0 .5～ 3h,bcl- 2强表达于缺血区皮质和纹状体的纤维 ,呈丝网状 ;6～ 12 h,丝网状的阳性纤维呈树枝状 ;2 4～ 48h,纹状体丝网状纤维和皮质树枝状的突起尤为突出。正常组 ,bax强表达于一些核团如视交叉上核、背内侧核等 ;0 .5～ 3h,缺血中心区皮质和纹状体 bax阴性 ,周边区有少量中等阳性的细胞 ;2 4～ 48h,缺血区皮质、尾壳核有少量散在的中等阳性神经元。结论 bcl- 2和 bax分别强表达于缺血区和缺血周边区的神经元 ,在神经元的存活或死亡中起作用。

Objective To study the involvement of Bcl 2 and Bax in neuronal Apoptosis in rat following ischemia reperfusion. Methods The cerebral ischemia was established by occluding middle cerebral artery (MCA) for 2 hours and reperfusing 0.5 48hours. The distribution of bcl 2 and bax were analyzed by immunohistochemical method. Results Immunoreactivity of bcl 2 was detected in neuronal membranes and processes in normal hemisphere, especially in fiber bundles. At 0.5 3hours, bcl 2 strongly expressed in slender fibers of ischemic cortex and striatum; At 6 12hours, the slender fibers became stout; At 24 48hours, the slender fibers of striatum and dendritic process of ischemic cortex were in particularly conspicuous. In normal cerebral hemisphere, Bax strongly expressed in some nucleus, for example, supraoptic hypothalamic nucleus and mediodorsal thalamic nucleus. At 0.5 3hours, the bax immunostaining was not detected in the ischemic center of cortex and striatum, the bax moderately immunostaining was detected in peri ischemic region. At 24 48hours, a few of scattered neurons appeared moderately positive in ischemic cortex and striatum. Conclusions bcl 2 and bax strongly expressed in the ischemic and peri ischemic areas, respectively. They would play a role in neuronal survival or death in ischemia.