Document Detail


Theoretical simulation of oxygen transport to brain by networks of microvessels: effects of oxygen supply and demand on tissue hypoxia.
MedLine Citation:
PMID:  10963629     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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 microm x 150 microm x 160 microm. 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 cm3O2/100 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.
Authors:
T W Secomb; R Hsu; N B Beamer; B M Coull
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Microcirculation (New York, N.Y. : 1994)     Volume:  7     ISSN:  1073-9688     ISO Abbreviation:  Microcirculation     Publication Date:  2000 Aug 
Date Detail:
Created Date:  2000-12-04     Completed Date:  2001-01-11     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  9434935     Medline TA:  Microcirculation     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  237-47     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of Arizona, Tucson 85724-5051, USA. secomb@u.arizona.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Biological Transport
Blood Flow Velocity
Brain / blood supply,  metabolism
Cell Hypoxia / drug effects
Cerebrovascular Circulation / physiology*
Computer Simulation
Corrosion Casting
Hypoxia, Brain / blood
Microcirculation
Microscopy, Electron, Scanning
Models, Biological
Oxygen / blood*,  pharmacology
Oxygen Consumption
Perfusion
Rats
Grant Support
ID/Acronym/Agency:
HL07249/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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