Cargando…
Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients
The permeability coefficients of dog red cell membrane to tritiated water and to a series of[(14)C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell col...
Autores principales: | , , |
---|---|
Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1974
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226182/ https://www.ncbi.nlm.nih.gov/pubmed/4443795 |
_version_ | 1782149797448253440 |
---|---|
author | Redwood, W. R. Rall, E. Perl, W. |
author_facet | Redwood, W. R. Rall, E. Perl, W. |
author_sort | Redwood, W. R. |
collection | PubMed |
description | The permeability coefficients of dog red cell membrane to tritiated water and to a series of[(14)C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell column was pulsed at one end with radiolabeled solute and diffusion was allowed to proceed for several hours. The distribution of radioactivity along the red cell column was measured by sequential slicing and counting, and the diffusion coefficient was determined by a simple plotting technique, assuming a one-dimensional diffusional model. In order to derive the red cell membrane permeability coefficient from the bulk diffusion coefficient, the red cells were assumed to be packed in a regular manner approximating closely spaced parallelopipeds. The local steady-state diffusional flux was idealized as a one-dimensional intracellular pathway in parallel with a one-dimensional extracellular pathway with solute exchange occurring within the series pathway and between the pathways. The diffusion coefficients in the intracellular and extracellular pathways were estimated from bulk diffusion measurements through concentrated hemoglobin solutions and plasma, respectively; while the volume of the extracellular pathway was determined using radiolabeled sucrose. The membrane permeability coefficients were in satisfactory agreement with the data of Sha'afi, R. I., C. M. Gary-Bobo, and A. K. Solomon (1971. J. Gen. Physiol. 58:238) obtained by a rapid-reaction technique. The method is simple and particularly well suited for rapidly permeating solutes. |
format | Text |
id | pubmed-2226182 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1974 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-22261822008-04-23 Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients Redwood, W. R. Rall, E. Perl, W. J Gen Physiol Article The permeability coefficients of dog red cell membrane to tritiated water and to a series of[(14)C]amides have been deduced from bulk diffusion measurements through a "tissue" composed of packed red cells. Red cells were packed by centrifugation inside polyethylene tubing. The red cell column was pulsed at one end with radiolabeled solute and diffusion was allowed to proceed for several hours. The distribution of radioactivity along the red cell column was measured by sequential slicing and counting, and the diffusion coefficient was determined by a simple plotting technique, assuming a one-dimensional diffusional model. In order to derive the red cell membrane permeability coefficient from the bulk diffusion coefficient, the red cells were assumed to be packed in a regular manner approximating closely spaced parallelopipeds. The local steady-state diffusional flux was idealized as a one-dimensional intracellular pathway in parallel with a one-dimensional extracellular pathway with solute exchange occurring within the series pathway and between the pathways. The diffusion coefficients in the intracellular and extracellular pathways were estimated from bulk diffusion measurements through concentrated hemoglobin solutions and plasma, respectively; while the volume of the extracellular pathway was determined using radiolabeled sucrose. The membrane permeability coefficients were in satisfactory agreement with the data of Sha'afi, R. I., C. M. Gary-Bobo, and A. K. Solomon (1971. J. Gen. Physiol. 58:238) obtained by a rapid-reaction technique. The method is simple and particularly well suited for rapidly permeating solutes. The Rockefeller University Press 1974-12-01 /pmc/articles/PMC2226182/ /pubmed/4443795 Text en Copyright © 1974 by The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Redwood, W. R. Rall, E. Perl, W. Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title | Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title_full | Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title_fullStr | Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title_full_unstemmed | Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title_short | Red Cell Membrane Permeability Deduced from Bulk Diffusion Coefficients |
title_sort | red cell membrane permeability deduced from bulk diffusion coefficients |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2226182/ https://www.ncbi.nlm.nih.gov/pubmed/4443795 |
work_keys_str_mv | AT redwoodwr redcellmembranepermeabilitydeducedfrombulkdiffusioncoefficients AT ralle redcellmembranepermeabilitydeducedfrombulkdiffusioncoefficients AT perlw redcellmembranepermeabilitydeducedfrombulkdiffusioncoefficients |