Maeda M, Akai F, Nishida S, Yanagihara T
Department of Neurology, Mayo Clinic, Rochester, Minnesota.
Acta Neuropathol. 1992;84(1):59-66. doi: 10.1007/BF00427216.
The blood-brain barrier breaks down following cerebral ischemia, but the exact sequence of events for extravasation of serum proteins and their parenchymal distribution remain uncertain. We studied the distribution of serum albumin in the hippocampus of the gerbil brain using light and electron microscopic immunocytochemical techniques. With light microscopy, there was no reaction for albumin for the first 12 h after unilateral common carotid artery occlusion for 10 min and reperfusion. At 12 h, the reaction was weak and limited to the neuropil in the subiculum-CA1 region (between the subiculum and the medial CA1 region). After 24 h, the reaction became intense in the neuropil and neuronal perikarya in the subiculum-CA1 and medial CA1 regions. The electron microscopic immunocytochemical study of the subiculum-CA1 and medial CA1 regions revealed electron-dense immunoprecipitates in the extracellular space and the peripheral part of the apical dendrites as early as 30 min after reperfusion and in the astrocytic cytoplasm after reperfusion for 1 h. However, immunoprecipitates were not found in the neuronal perikarya until after reperfusion for 24 h. The present study demonstrated prompt appearance of albumin in the extracellular space of the brain parenchyma after re-establishment of cerebral circulation and prompt accumulation in the peripheral part of the dendrites with spreading to neuronal perikarya, likely in the process of degeneration and death.
脑缺血后血脑屏障会遭到破坏，但血清蛋白外渗的具体事件序列及其在实质组织中的分布仍不明确。我们运用光镜和电镜免疫细胞化学技术，研究了沙鼠脑海马区血清白蛋白的分布情况。光镜观察显示，单侧颈总动脉闭塞10分钟并再灌注后的最初12小时内，白蛋白无反应。12小时时，反应较弱，仅限于下托 - CA1区（在下托与内侧CA1区之间）的神经纤维网。24小时后，下托 - CA1区和内侧CA1区的神经纤维网和神经元胞体中的反应变得强烈。对下托 - CA1区和内侧CA1区的电镜免疫细胞化学研究表明，再灌注后30分钟，细胞外间隙和顶端树突的周边部分就出现了电子致密免疫沉淀物，再灌注1小时后，星形胶质细胞胞质中也出现了免疫沉淀物。然而，直到再灌注24小时后，神经元胞体中才发现免疫沉淀物。本研究表明，脑循环恢复后，白蛋白迅速出现在脑实质的细胞外间隙，并迅速在树突周边部分积聚，随后扩散到神经元胞体，这可能发生在退变和死亡过程中。
