Time-dependent diffusion of water in a biological model system

Latour, L. L., Svoboda, K., Mitra, P. P., Sotak, C. H. (February 1994) Time-dependent diffusion of water in a biological model system. Proc Natl Acad Sci U S A, 91 (4). pp. 1229-33. ISSN 0027-8424

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Abstract

Packed erythrocytes are ideally suited as a model system for the study of water diffusion in biological tissue, because cell size, membrane permeability, and extracellular volume fraction can be varied independently. We used a pulsed-field-gradient spin echo NMR technique to measure the time-dependent diffusion coefficient D(t) in packed erythrocytes. The long-time diffusion constant, D(eff), depends sensitively on the extracellular volume fraction. This may explain the drop in D(eff) during the early stages of brain ischemia, where just minutes after an ischemic insult the extra-cellular volume in the affected region of the brain is significantly reduced. Using an effective medium formula, we estimate the erythrocyte membrane permeability, in good agreement with measurements on isolated cells. From the short-time behavior of D(t), we determine the surface-to-volume ratio of the cells, approximately (0.72 micron)-1.

Item Type: Paper
Additional Information:
Uncontrolled Keywords: Animals Biological Transport Brain Ischemia Cattle Cell Membrane Permeability Cell Size Diffusion Erythrocyte Membranemetabolism Humans Magnetic Resonance Spectroscopy methods Models Biological Models Theoretical Surface Properties Time Factors Water metabolism
Subjects: physics > biophysics
bioinformatics > computational biology
physics > fluid dynamics
physics > biophysics > membrane dynamics
organs, tissues, organelles, cell types and functions > tissues types and functions > transport > membrane transport
physics > biophysics > pore dynamics
CSHL Authors:
Communities: CSHL labs > Mitra lab
Depositing User: CSHL Librarian
Date: 15 February 1994
Date Deposited: 04 Apr 2012 19:55
Last Modified: 09 Nov 2017 19:40
PMCID: PMC43130
Related URLs:
URI: https://repository.cshl.edu/id/eprint/25846

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