Lo W D, Wolny A C, Timan C, Shin D, Hinkle G H
Department of Pediatrics, Ohio State University, Columbus.
J Neurol Sci. 1993 Sep;118(2):188-93. doi: 10.1016/0022-510x(93)90109-c.
The diffusion properties of the brain cortical extracellular space have never been examined in models of inflammation, even though inflammation can cause increased blood-brain barrier permeability. Uptake of intravascular 125I-labelled albumin and the diffusion of the tetramethylammonium ion within the brain extracellular space was measured in an experimental brain abscess to determine the effect of acute inflammation upon blood-brain barrier permeability and diffusion properties of the cortical extracellular space. The blood-brain transfer constant for albumin was increased in the abscess region, indicating that an increase in blood-brain barrier permeability occurred in animals inoculated with a weakly pathogenic strain of Staphylococcus aureus. The volume fraction of the extracellular space, as measured by the diffusion of tetramethylammonium ion, ranged from 0.19 to 0.23 in bacteria inoculated subjects and from 0.21 to 0.22 in controls. The tortuosity of the extracellular space ranged from 1.40 to 1.42 in bacteria inoculated subjects and was 1.39 in controls. These results showed that the volume fraction and tortuosity of the cortical extracellular space were not affected by inflammation even though vascular permeability was increased. This result was supported by the finding that brain water content, measured in the same animals, was increased to a non-significant extent in the bacteria inoculated subjects. These findings lead to the conclusion that acute inflammation induced by a weak pathogen can cause increased blood-brain barrier permeability without a significant change in the diffusion properties of the brain cortical space.
尽管炎症可导致血脑屏障通透性增加，但在炎症模型中从未对大脑皮质细胞外间隙的扩散特性进行过研究。在实验性脑脓肿中测量血管内125I标记白蛋白的摄取以及四甲基铵离子在脑细胞外间隙中的扩散，以确定急性炎症对血脑屏障通透性和皮质细胞外间隙扩散特性的影响。脓肿区域白蛋白的血脑转运常数增加，表明接种弱致病性金黄色葡萄球菌菌株的动物血脑屏障通透性增加。通过四甲基铵离子扩散测量的细胞外间隙体积分数，在接种细菌的受试者中为0.19至0.23，在对照组中为0.21至0.22。接种细菌的受试者细胞外间隙的曲折度为1.40至1.42，对照组为1.39。这些结果表明，即使血管通透性增加，皮质细胞外间隙的体积分数和曲折度也不受炎症影响。在同一动物中测量的脑含水量在接种细菌的受试者中增加到不显著的程度，这一发现支持了这一结果。这些发现得出结论，弱病原体引起的急性炎症可导致血脑屏障通透性增加，而大脑皮质空间的扩散特性无显著变化。
