DETERMINATION OF BRAIN INTERSTITIAL CONCENTRATIONS BY MICRODIALYSIS
DETERMINATION OF BRAIN INTERSTITIAL CONCENTRATIONS BY MICRODIALYSIS
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DOI：
10.1111/j.1471-4159.1989.tb07252.x
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发表时间：
1989-06-01
影响因子：
4.7
通讯作者：
OTTOSEN, NS
中科院分区：
文献类型：
--
作者：
BENVENISTE, H;HANSEN, AJ;OTTOSEN, NS
微透析法是一种广泛应用于脑间质溶质研究的技术。这种方法是基于通过在大脑中的透析膜上扩散来收集物质。流出浓度反映了感兴趣物质的间隙浓度，但这两个实体之间的关系目前尚不清楚。到目前为止，大多数评估都是完全基于生理盐水的校准。这一过程具有误导性，因为生理盐水中的分子扩散到探针中的容易程度与组织中的不同。在这里，我们描述了基于复杂介质中的扩散方程的组织中进入透析器的质量传输的数学分析。主要的发现是，给定物质的扩散特性必须包含在公式中。其中包括曲折系数.lambda。和细胞外体积分数(α)。我们通过在定义明确的复杂介质(红细胞悬浮液)和大脑中进行的研究证实了这一点。我们的结论是，传统的计算程序导致间隙浓度太低，是λ2/α的系数。对于给定的化合物。
Microdialysis is an extensively used technique for the study of solutes in brain interstitial space. The method is based on collection of substances by diffusion across a dialysis membrane positioned in the brain. The outflow concentration reflects the interstitial concentration of the substance of interest, but the relationship between these two entities is at present unclear. So far, most evaluation have been based solely on calibrations in saline. This procedure is misleading, because the ease by which molecules in saline diffuse into the probe is different from that of tissue. We describe here a mathematical analysis of mass transport into the dialysis probe in tissue based on diffusion equations in complex media. The main finding is that diffusion characteristics of a given substance have to be included in the formula. These include the tortuosity factor .lambda. and the extracellular volume fraction (.alpha.). We have substantiated this by studies in a well-defined complex medium (red blood cell suspensions) as well as in brain. We conclude that the traditional calculation procedure results in interstitial concentrations that are too low by a factor of .lambda.2/.alpha. for a given compound.