Theoretical simulation of oxygen transport to brain by networks of microvessels: Effects of oxygen supply and demand on tissue hypoxia

T. W. Secomb, R. Hsu, N. B. Beamer, B. M. Coull

Research output: Contribution to journalArticle

66 Scopus citations

Abstract

Objective: Simulations of oxygen delivery by a three-dimensional network of microvessels in rat cerebral cortex were used to examine how the distribution of partial pressure of oxygen (Po2) in tissue depends on blood flow and oxygen consumption rates. Methods: Network geometry was deduced from previously published scanning electron micrographs of corrosion casts. A nonlinear least-squares method, using images obtained at three different angles, was used to estimate vessel locations. The network consisted of 50 segments in a region 140 μm × 150 μm × 160 μm. A Green's function method was used to predict the Po2 distribution. Effects of varying perfusion and consumption were examined, relative to a control state with consumption 10 cm3 O2/100 g per min and perfusion 160 cm3/100 g per min. Results: In the control state, minimum tissue Po2 was 7 mm Hg. A Krogh-type model with the same density of vessels, but with uniform spacing, predicted a minimum tissue Po2 of 23 mm Hg. For perfusion below 60% of control, tissue hypoxia (Po2 <1 mm Hg) was predicted. When perfusion was reduced by 75%, the resulting hypoxia could be eliminated by a 31% reduction in oxygen consumption rate. Conclusions: The simulations suggest that tissue hypoxia resulting from a severe decrease in brain perfusion, as can occur in stroke, may be avoided by a moderate decrease in oxygen consumption rate. Microcirculation (2000) 7, 237-247.

Original languageEnglish (US)
Pages (from-to)237-247
Number of pages11
JournalMicrocirculation
Volume7
Issue number4
StatePublished - Dec 1 2000

Keywords

  • Capillary network
  • Oxygen consumption
  • Oxygen supply
  • Stroke
  • Theoretical model
  • Tissue hypoxia

ASJC Scopus subject areas

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

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