The Relation Between Capillary Transit Times and Hemoglobin Saturation Heterogeneity. Part 2: Capillary Networks
Affiliation
Univ Arizona, Dept PhysiolIssue Date
2018-09-21Keywords
blood flowcapillary transit time heterogeneity
computational modeling
hematocrit
hemoglobin saturation
microcirculation
oxygen transport
red blood cells
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FRONTIERS MEDIA SACitation
Lücker A, Secomb TW, Barrett MJP, Weber B and Jenny P (2018) The Relation Between Capillary Transit Times and Hemoglobin Saturation Heterogeneity. Part 2: Capillary Networks. Front. Physiol. 9:1296. doi: 10.3389/fphys.2018.01296Journal
FRONTIERS IN PHYSIOLOGYRights
© 2018 Lücker, Secomb, Barrett, Weber and Jenny. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Brain metabolism is highly dependent on continuous oxygen supply. Cortical microvascular networks exhibit heterogeneous blood flow, leading to non-uniform tissue oxygenation and capillary hemoglobin saturation. We recently proposed capillary outflow saturation heterogeneity (COSH) to represent effects of heterogeneity on oxygen supply to tissue regions most vulnerable to hypoxia, and showed that diffusive oxygen exchange among red blood cells within capillaries and among capillaries (diffusive interaction) significantly reduces COSH in simplified geometrical configurations. Here, numerical simulations of oxygen transport in capillary network geometries derived from mouse somatosensory cortex are presented. Diffusive interaction was found to reduce COSH by 41 to 62% compared to simulations where diffusive interaction was excluded. Hemoglobin saturation drop across the microvascular network is strongly correlated with red blood cell transit time, but the coefficient of variation of saturation drop is approximately one third lower. Unexpectedly, the radius of the tissue cylinder supplied by a capillary correlates weakly with the anatomical tissue cylinder radius, but strongly with hemoglobin saturation. Thus, diffusive interaction contributes greatly to the microcirculation's ability to achieve tissue oxygenation, despite heterogeneous capillary transit time and hematocrit distribution. These findings provide insight into the effects of cerebral small vessel disease on tissue oxygenation and brain function.Note
Open access journal.ISSN
1664-042XVersion
Final published versionSponsors
Swiss National Science Foundation [140660]; U.S. National Institutes of Health [HL133362]Additional Links
https://www.frontiersin.org/articles/10.3389/fphys.2018.01296/fullae974a485f413a2113503eed53cd6c53
10.3389/fphys.2018.01296
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Except where otherwise noted, this item's license is described as © 2018 Lücker, Secomb, Barrett, Weber and Jenny. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).