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Determination of Brain Interstitial Concentrations by Microdialysis

Benveniste, Helene; Hansen, Anker Jon and Ottosen, Niels Saabye LU (1989) In Journal of Neurochemistry 52(6). p.1741-1750
Abstract
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 evaluations 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... (More)
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 evaluations 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 (λ) and the extracellular volume fraction (α). We have substantiated this by studies in a welldefined 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 λ2/α for a given compound. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Interstitial space size, Tortuosity factor, Diffusion characteristics, Mass transport, Complex media, Diffusion equations, Brain interstitial space, Microdialysis
in
Journal of Neurochemistry
volume
52
issue
6
pages
1741 - 1750
publisher
Wiley-Blackwell
external identifiers
  • Scopus:0024390845
ISSN
1471-4159
DOI
10.1111/j.1471-4159.1989.tb07252.x
language
English
LU publication?
yes
id
5f3f4b72-4b5a-46d4-8737-89b0c045e0aa (old id 1370120)
date added to LUP
2010-08-25 14:28:14
date last changed
2016-12-04 04:48:18
@misc{5f3f4b72-4b5a-46d4-8737-89b0c045e0aa,
  abstract     = {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 evaluations 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 (λ) and the extracellular volume fraction (α). We have substantiated this by studies in a welldefined 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 λ2/α for a given compound.},
  author       = {Benveniste, Helene and Hansen, Anker Jon and Ottosen, Niels Saabye},
  issn         = {1471-4159},
  keyword      = {Interstitial space size,Tortuosity factor,Diffusion characteristics,Mass transport,Complex media,Diffusion equations,Brain interstitial space,Microdialysis},
  language     = {eng},
  number       = {6},
  pages        = {1741--1750},
  publisher    = {ARRAY(0xb8507f0)},
  series       = {Journal of Neurochemistry},
  title        = {Determination of Brain Interstitial Concentrations by Microdialysis},
  url          = {http://dx.doi.org/10.1111/j.1471-4159.1989.tb07252.x},
  volume       = {52},
  year         = {1989},
}