新生鼠缺血缺氧性脑病中神经干细胞的形态学观察

【目的】建立新生鼠缺血缺氧性脑病动物模型，探讨HIE病程中神经干细胞（neural stem cells，NSCs）的形态学改变。【方法】210只新生7d SD乳鼠随机分为正常对照组、单纯缺氧组及缺血缺氧组。每组70只。每组又根据处死时间点随机分成3h，6h，1d，3d，7d，14d，21d等7个小组。每小组10只。缺血缺氧组结扎新生7d SD大鼠左颈总动脉，置于8％氧浓度的低氧环境中2．5h。单纯缺氧组缺氧2．5h。采用HE染色、免疫组织化学染色以及光镜技术分别对3组SD大鼠脑组织中的NSCs形态学进行检测。【结果】缺血缺氧组缺血缺氧后3h出现轻度脑损伤，1d病变最严重．3d、7d胶质细胞增生．14d、21d出现脑萎缩。3组SD鼠在7个时间点脑组织均存在NSCs，且细胞呈单一的圆形，突起不超过1个．阳性NSCs呈明显的区域性分布．神经球集落样存在的NSCs较多，单纯缺氧组在每一时间点NSCs的表达明显高于缺血缺氧组及正常对照组。在6h时间点，处于增殖状态的NSCs增多，尤其是室下区。1d和3d时间点，坏死脑组织中仍可见NSCs及其神经球。3d时间点后病侧脑组织的NSCs逐渐下降。【结论】成功建立了缺血缺氧性脑病动物模型；HIE发病中早期NSCs增殖；NSCs随着病情的演变开始减少；低氧有利于NSCs的增殖；早期采用NSCs干预治疗有希望成为临床治疗HIE的重要途径。

Observation on cell morphology of neural stem cells in hypoxic ischemic encephalopathy

[Objective] To establish the neonatal rat models of hypoxic-ischemic encephalopathy and investigate morphologic features of neural stem cells(NSCs) in episode of hypoxic ischemic encephalopathy (HIE). [Methods] 210 neonatal rats at age 7d were divided randomly into three groups: control group,hypoxic group and hypoxicischemic group,each one had 70 rats. 70 rats of every group divided randomly into seven sub groups, including 3h,6h, 1d,3d,7d,14d and 21d,according to the time to put to death,each one had 10 rats. Left common carotid artery of neonatal rats at age 7d in hypoxic-ischemic group were ligated. Then, The rats of hypoxic and hypoxic-ischemic group were put into a state with 8% oxygen in 2. 5h. NSCs from brain tissues of rats in three groups were determined with HE staining and immunohistochemical method under light microscope. [Results] In hypoxic-ischemic group, light brain injury was presented at 3h point,severe brain injury was presented at 1d point,Glial cells were proliferated at 3d and 7d points,brain atrophy was presented at 14d and 21d points. NSCs were existed in brain tissues of rats in three groups and with single round shape, enation of every NSCs was no more than one. NSCs presented obviously regional distribution, especially neurospheres. At every time point, expression of NSCs in hypoxic-ischemic group was higherthan that in control group and hypoxic group. At 6h point,NSCs in a proliferating state increased,especially in subventricular zone. At 1d and 3d points, NSCs and neuro spheres remained to be seen in necrotic brain tissues. NSCs in brain tissues at diseasing side decreased gradually From 3d to end. [Conclusions] The neonatal rat models of HIE have been success fully established. NSCs exist in episode of HIE proliferated in earier period and decreased with variation of state of an illness. Hypoxia benefited NSCs proliferation. To use NSCs for intervention therapy in earier period may be the prospective way for treating HIE in clinic.