延髓缺血对其微血管密度、神经元及神经胶质细胞的影响

The changes of the microvessel density and effects of neurons and glial cells in medulla after medullary ischemia in rats

目的观察延髓缺血后不同时段微血管、神经元、神经胶质细胞的改变。方法雄性Wistar大鼠共48只,随机分成4组,即实验组(1w组、2w组、3w组)和对照组,每组12只。采用电凝法及丝线结扎法,阻断双侧椎动脉及右侧颈总动脉制作延髓缺血模型。观察延髓缺血后不同时段微血管密度、神经元、神经胶质细胞的改变。采用单宁酸-氯化铁媒染法显示延髓内部微血管;Mivnt图像分析系统定量分析微血管密度(MVD)及微血管面积比(MVA);HE法显示延髓内部神经元、神经胶质细胞。常规石蜡包埋,连续切片(片厚5μm),每只大鼠观察4张切片,每张切片在200倍光镜下选取5个视野,计数神经元或神经胶质细胞细胞核数/总细胞核比值,取其平均值为神经元、神经胶质细胞数。结果延髓缺血后微血管密度、微血管面积比出现先减少再渐增多的变化趋势(P<0.05);呈现神经元减少(P<0.05)、神经胶质细胞数量增多的趋势(P<0.05)。结论脑缺血后,随着观察时间的延长,呈现神经元减少,有的神经元内部结构出现了不可逆转的损伤,同时神经胶质细胞数量增多,随时间延长增多越明显,说明脑缺血后延髓神经元坏死不能再生,而被神经胶质细胞所充填替代。

Objective To observe the changes of the microvasculature,neurons and glial cells in rats medullas in different periods of medullary ischemia.Methods 48 healthy adult male Wistar rats（200～220g） were divided randomly into four groups：experimental group（one week group,two weeks group,three weeks group） and control group,12 rats in each group.The experimental group were ligated the right common carotid artery and blocked the bilateral vertebral by electrocoagulation to make the medullary ischemia model.To observe the changes of the microvascular density,neurons and glial cells in rats medullas in different periods of medullary ischemia.Staining medullary microvascular with tannic acid-ferric chloride method（TA-FE method）.MiVnt image analytical system was used to quantitatively analyze the microvessel density（MVD） and the microvessel area density（MVA） of medulla.HE Staining was used to investigate neurons and glial cells（neuroglia cell） in medullary internal.Of each rat,four slices were observed.Under optical microscope at 200 times,5 visual fields were randomly chosen from each slices to count the number of neurons and glial cells.Results Animal models of different times of the experimental group showed that the microvascular density and microvascular area ratio appeared reducing trends（P0.05）.The number of glial cells showed a continuous increasing trend（P0.05）.Change in the number of neurons appears a decreasing trend（P0.05）.Conclusion The change,neurons first increasing then reducing but glial cells increasing after the medullary ischemia,can be observed definitely in the HE method.At the same time,the irrersible damage to the structure of neurons also can be showed clearly.