Effect of aggregation and shear rate on the dispersion of red blood cells flowing in venules

Jeffrey J. Bishop, Aleksander S. Popel, Marcos Intaglietta, Paul C. Johnson

Research output: Contribution to journalArticlepeer-review

Abstract

Previous in vitro studies of blood flow in small glass tubes have shown that red blood cells exhibit significant erratic deviations in the radial position in the laminar flow regime. The purpose of the present study was to assess the magnitude of this variability and that of velocity in vivo and the effect of red blood cell aggregation and shear rate upon them. With the use of a gated image intensifier and fluorescently labeled red blood cells in tracer quantities, we obtained multiple measurements of red blood cell radial and longitudinal positions at time intervals as short as 5 ms within single venous microvessels (diameter range 45-75 μm) of the rat spinotrapezius muscle. For nonaggregating red blood cells in the velocity range of 0.3-14 mm/s, the mean coefficient of variation of velocity was 16.9 ± 10.5% and the SD of the radial position was 1.98 ± 0.98 μm. Both quantities were inversely related to shear rate, and the former was significantly lowered on induction of red blood cell aggregation by the addition of Dextran 500 to the blood. The shear-induced random movements observed in this study may increase the radial transport of particles and solutes within the bloodstream by orders of magnitude.

Original languageEnglish (US)
Pages (from-to)H1985-H1996
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume283
Issue number5 52-5
DOIs
StatePublished - Nov 1 2002

Keywords

  • Dispersion coefficient
  • In vivo fluorescence microscopy
  • Red blood cell aggregation
  • Shear-induced particle diffusion
  • Solute transport

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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