后适应对树鼩不同脑缺血模型同一“时间窗”海马神经元保护的比较  

Effects of ischemic postconditioning on hippocampal neuroprotection in different cerebral ischemia models at the same "time window" in tree shrews

作　　者：李树清[1] 罗海芸[1] 俞志成[1] 

机构地区：[1]昆明医学院病理生理学教研室,云南昆明650031

出　　处：《中国病理生理杂志》2011年第5期890-894,共5页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.30660056No.30971171);教育部博士点专项科研基金资助项目(No.20050678008)

摘　　要：目的:观察缺血后适应(PC)对血栓性脑缺血(TC)及大脑中动脉闭塞(MCAO)2种脑缺血模型同一"时间窗"的脑保护效果,并探讨其可能机制。方法:建立树鼩TC及MCAO脑缺血模型,于脑缺血后4 h夹闭同侧颈总动脉实施缺血PC。用TTC染色显示皮层梗塞面积,采用电镜及激光多普勒(LD)技术分别观察脑缺血后4h、24 h及72 h海马CA1区神经元超微结构及局部脑血流(rCBF)的变化,比较PC对2种中风模型海马rCBF和神经元超微结构的影响。结果:脑缺血后海马CA1区神经元的超微结构改变以线粒体肿胀、嵴断裂以及内质网扩张为主,MCAO的梗塞面积和细胞损伤程度明显高于TC组,且PC缓减TC组海马线粒体损伤的作用较MCAO的明显。TC和MCAO后海马rCBF明显降低,TC组rCBF的降低以24 h明显(P<0.01),而MCAO组rCBF的降低则以72 h明显(P<0.01)。脑缺血后4 h实施PC可改善TC组海马rCBF(P<0.01)和减轻线粒体损伤,而MCAO组rCBF及神经元形态学改善不明显。结论:脑缺血后4 h实施缺血PC能有效对抗缺血性脑损伤,其脑保护效果与rCBF的增加有关。缺血PC对TC组的脑保护作用较MCAO组明显。AIM： To compare the effects of ischemic postconditioning（PC） on hippocampal neuroprotection between thrombotic cerebral ischemia（TC） and middle cerebral artery occlusion（MCAO） models in tree shrews,and to explore the neural pretection mechanisms of PC at the same ＂time windows＂.METHODS： The TC and MCAO models were established and ischemic PC was operated by cliped ipsilateral carotid artery of the animals 4 h after cerebral ischemia.The cortex infarct size was measured by 2,3,5-triphenyltertrazolium chloride（TTC） staining.The changes of neuronal ultrastructures and the regional cerebral blood flow（rCBF） in hippocampal CA1 area were observed 4 h,24 h and 72 h after cerebral ischemia by the method of electronic microscopy and laser Doppler technique,respectively.RESULTS： The mitochondria swelling,the cristae disorganizing and the expansion of endoplasmic reticulum were observed in hippocampal CA1 area after TC and MCAO.The infarct size and cell damage induced by MCAO were more severe than those induced by TC.The rCBF in hippocampus was significantly decreased after TC and MCAO.rCBF in TC group was markedly decreased at 24 h（P0.01） and rCBF in MCAO group was decreased at 72 h（P0.01） after cerebral ischemia.The improvement of hippocampal rCBF and reduction of mitochondrial damage by PC in TC group were more effective than those in MCAO group.CONCLUSION： Operation of PC at 4 h after cerebral ischemia has neuroprotective effects against cerebral ischemia injury.The protective effects of PC are more effective in TC model than those in MCAO model by improving rCBF in hippocampus.

关 键 词：光化学 脑缺血 后处理 海马 超微结构 局部脑血流 树鼩 

分 类 号：R363[医药卫生—病理学]