慢性脑缺血大鼠模型中海马神经元凋亡与缺血时间的相关性  

Correlation Study between the Time of Chronic Cerebral Ischemia and Hippocampal Neuron Apoptosis in Rats

作　　者：杨振军[1] 史昌乾 薛景凤[1] 

机构地区：[1]承德医学院解剖教研室,河北承德067000 [2]武警辽宁总队大连医院院长办公室,辽宁大连116013

出　　处：《中国医科大学学报》2015年第1期55-59,共5页Journal of China Medical University

基　　金：河北省科技厅计划支持项目(13277772D)

摘　　要：目的探讨慢性脑缺血加速大鼠海马神经元凋亡的作用,初步阐明其机制。方法健康成年雄性SD大鼠90只,随机分为假手术组(n=30)和实验组(n=60),分别于术后第7、14和21天处死取材,每个时间点随机选取假手术组大鼠10只、实验组大鼠20只。实验组大鼠采用结扎双侧颈总动脉的方法,建立慢性脑缺血模型;假手术组颈部正中切口,分离双侧颈总动脉,不做结扎。硫堇染色观察大鼠海马神经元的形态变化;SP免疫组织化学法观察海马神经元Bax和Bcl-2蛋白表达的动态变化;单宁酸-氯化铁媒染法观察大鼠海马微血管构筑的动态变化。采用Mi Vnt图像分析系统对大鼠海马神经元Bax和Bcl-2蛋白表达、海马微血管密度(MVD)、微血管面积(MVA)进行定量分析。结果实验组大鼠海马神经元Bcl-2蛋白的表达率与假手术组相比明显降低(P<0.05);且随缺血时间的延长,Bcl-2蛋白的表达率逐渐下调,21 d实验组明显低于与7 d实验组(P<0.05)。实验组大鼠海马神经元Bax蛋白的表达率与假手术组相比明显升高(P<0.05);且随缺血时间的延长,Bax蛋白的表达率逐渐上调,21 d实验组明显高于7 d和14 d实验组(P<0.05)。实验组各时间点大鼠海马的MVA和MVD均较假手术组明显下降(P<0.05);随着造模时间的延长,MVA和MVD逐渐下降,14 d和21 d实验组的MVA和MVD明显低于7 d实验组(均P<0.05),且21 d实验组的MVD明显低于14 d实验组(P<0.05)。结论慢性脑缺血可致海马MVA、MVD及Bcl-2蛋白的表达进行性下降,Bax蛋白的表达进行性增高,进而导致学习和记忆功能障碍逐渐加重,这可能是血管性痴呆的原因之一。Objective To investigate the effects ofthe chronic cerebral ischemia on the rats＇ hippocampal neurons , and to explore its mechanism. Methods A total of 90 healthy, adult male SD rats were applied in this study and randomly divided into sham operation group （n =30） and experi- menial group （n =60）. The rats in both groups were respectively sacrificed 7-day, 14-day and 21 -day after operation, with each time point of 10 from sham operation group and 20 from experimental group. The chronic cerebral ischemia rats model were established by permanently ligating the common carotid arteries on both sides of rats, as experimental group. Sham operation group were established by incise cervical median, only separat- ed common carotid arteries on both sides, not ligated. Thionine staining was used to observe the morphological changes of hippocampus neurons. Im- munohistoehemistry staining was used to observe dynamic changes of expression of Bcl-2 and Bax in hippocampns neurons, and MiVnt image analyt- ical system to quantitatively analyze the results. TA-FE method was used to detect the dynamic changes of hippocampal mierovaseualr architecture. MiVnt image analytical system to quantitatively analyze the microvessel density （MVD） and mieorvessel area density （MVA） of horizontal part of hippoeampus. Results Compared with sham operation group at the same time point, the Bel-2 expression in hippocampus neurons of experimental group were significantly lower （ P 〈 0.05 ）, and with time extension, the Bcl-2 expression gradually decreased. The Bcl-2 expression in 21-day exper- imental group were significantly lower than 7-day experimental group （P 〈 0.05 ）. Compared with sham operation group at the same time point, the Bax expression in hippocampus neurons of experimental group were significantly higher （P 〈 0.05 ） , and with time extension, the Bax expression gradually increased. The Bax expression in 21-day experimental group were significantly higher than 7-day and 14-day experimental group �

关 键 词：慢性脑缺血 海马 Bcl-2 BAX 微血管构筑 

分 类 号：R74[医药卫生—神经病学与精神病学]