【摘要】 目的:应用磁共振波谱(MRS)观察大鼠大脑中动脉缺血(MCAO)再灌流后海马迟发性神经元死亡和伴随的反应性星形胶质细胞增生,为评价血管性认知功能损害提供无创性观察指标。方法:W istar大鼠16只MCAO 1 h后再灌流及假手术对照组10只,6周后分别进行MRS和病理学对比观察,根据海马的形态、细胞密度变化及免疫组化结果分析磁共振波谱中N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)、肌酸和磷酸肌酸(Cr+PCr)、肌醇(m I)的对应性改变。结果:MCAO再灌流组大鼠缺血同侧海马的NAA、Cr及NAA/Cr的比值显著低于对侧和对照组,平均为2.05±0.33、2.42±0.41和0.86±0.10(对侧3.45±0.58、3.10±0.93、1.18±0.32,对照组3.42±0.43、3.57±0.47、0.98±0.14),m I和m I/Cr在缺血同侧海马(1.47、1.30)明显高于对照组(0.15、0.15)。结论:通过磁共振波谱的NAA和m I可以同时显示MCAO再灌流后海马的迟发性神经元死亡及伴随的反应性星形胶质细胞增生。但神经元的丢失程度与NAA存在不完全对应性,这种变化可能与反应性星形胶质细胞增生密切相关。更多还原

【Abstract】 AIM: By Applying magnetic resonance spectroscopy(MRS) to distinguish delayed neuronal death and reactive glial proliferation in ipsilateral hippocampus of MCAO reperfusion rats.METHODS: Sixteen adult Wistar rats with MCA occlusion for 1 h then perfusion through remove the embolus were used in the experiment.10 pseudooperaton rats were served as control.MRS and pathologic examination were performed six weeks after operation.The hippocampus modality,cell density and immunohistochemical results with N-acetylaspartate,creatine and myo-inositol changes were compared.RESULTS: The values of NAA,Cr and NAA/Cr ratio of ipsilateral hippocampus lesion in MCAO reperfusion rats(2.05±0.33,2.42±0.41 and 0.86±0.10) were decreased distinctly than those in opposite side(3.45±0.58,3.10±0.93,1.18±0.32) and control group(3.42±0.43,3.57±0.47,0.98±0.14).MI value and mI/Cr ratio in ischemic hippocampus(1.47,1.30) were visible increased than those in control group(0.15,0.15).CONCLUSIONS: MRS is a perfect technique for observing the cellular metabolic changes in CA1 region.Decrease in NAA resulted from neuron delayed injury and increase in mI resulted from reactive astrocytes proliferation can be matched respectively.However,the decrease in NAA is not perfectly corresponded to the degree of neuron lost.This change has closed correlation with reactive astrocytes proliferation.更多还原