亚低温对大鼠全脑缺血再灌注后海马CA1区星形胶质细胞胶质纤维酸性蛋白表达及超微结构改变的影响  

Effects of mild hypothermia on the expression of glial fibrillary acidic protein and ultrastructural changes in astrocytes in the hippocampal CA1 subfield following global cerebral ischemia and reperfusion

作　　者：韩立秀[1] 王兰琴[2] 董瑞国[3] 

机构地区：[1]山东枣庄市立医院感染科,枣庄277100 [2]徐州医学院附属第二医院神经内科 [3]徐州医学院附属第一医院神经内科

出　　处：《中华物理医学与康复杂志》2010年第11期826-830,共5页Chinese Journal of Physical Medicine and Rehabilitation

摘　　要：目的 研究大鼠全脑缺血再灌注后不同时间点海马CA1区星形胶质细胞胶质纤维酸性蛋白（GFAP）表达,观察超微结构变化,了解亚低温对其保护作用及影响.方法 制作大鼠全脑缺血模型,将96只大鼠分为常温组、亚低温组和假手术组,每组32只.根据缺血时间不同,每组再分为缺血6h、12h、24h、4d 4个亚组,每个亚组8只.苏木精-伊红（HE）染色观察海马CA1区细胞形态学改变,免疫组织化学方法检测胶质纤维酸性蛋白（GFAP）表达,原位氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL检测）及免疫组化双标染色观察海马CA1区星形胶质细胞的死亡方式,投射电镜观察星形胶质细胞超微结构改变,综合以上结果了解亚低温干预的效果.结果 大鼠全脑缺血再灌注后,GFAP表达随时间增加逐渐增强,亚低温组较常温组GFAP表达明显减少,4d时间点电镜下可见海马CA1区部分星形胶质细胞以胀亡形式死亡.结论 亚低温能明显减少GFAP的表达,对神经元有保护作用,全脑缺血再灌注后星形胶质细胞存在胀亡的死亡方式.Objective To observe the expression of glial fibrillary acidic protein （ GFAP）, and the pathological and ultrastructnral changes of astrocytes in the CA1 subfield of the hippocampus following global cerebral ischemia and reperfusion, and to explore the neuroprotective mechanism of mild hypothermia. Methods Global cerebral ischemia was established in rats by a modified version of Pulsinelli＇s method. Ninety-six rats were divided into three groups including a sham-operated group, a normothermic ischemic reperfusion （IR） group and a hypothermic ischemic reperfusion （HIR） group. Each group had four subgroups which were sacrificed for 6, 12 or 24 hours, or 4 days after reperfusion （for each subgroup n = 8 ）. Hematoxylin-eosin （HE） staining was used to observe morphological changes in neurons in the CA1 subfield of the hippocampus. TUNEL methods were used to detect apoptosis among those neurons. Immunohistochemical staining was used to detect the expression of GFAP in the CA1 subfield and the mechanism of astrocyte pathology. GFAP TUNEL double-labeled immunohistochemistry was used with both the shamoperated and experimental groups. Electron microscopy was also used to evaluate morphological changes in astrocytes 24 hours and 4 days after ischemia and reperfusion. Results Compared with the sham-operated group, expression of GFAP immunoreactive positive cells increased gradually in the CA1 subfield of the IR group rats. Compared with the IR group, expression of GFAP immunoreactive positive cells was significantly lower in the HIR group at all time points. Microscopic observation at the 4th day showed that some astrocytes in the CA1 subfield had died through oncosis. Conclusions Mild hypothermia can significantly decrease the expression of GFAP immunoreactive positive cells and the number of apoptotic neurons in the CA1 subfield of the hippocampus, minimize cell oedema and provide protection for neurons. Oncosis kills astrocytes following global cerebral ischemia and reperfusion.

关 键 词：全脑缺血再灌注 亚低温 星形胶质细胞 胶质纤维酸性蛋白 胀亡 

分 类 号：R285.5[医药卫生—中药学]