A simple model for prediction of oxygen transport rates by flowing blood in large capillaries

Nair, P. K.; Huang, Nancy Shu-Hui; Hellums, J. D.; Olson, John S.

doi:10.1016/0026-2862(90)90070-8

Cited by 44 publications

(48 citation statements)

References 12 publications

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“…For R = L and a 40% hematocrit this results in a capillary radius of 2.44 ¿¿m, which is a typical value for rat heart capillaries. The diffusion coefficient of oxygen in plasma is about 2* 10~9 m^s "1 (Groebe, 1990;Nair et aL, 1990). Based on a average RBC velocity of 1 mm-sH (Rakusan and Blahitka, 1974), Hoofd et a l (1990) calculated a value for a F /f which leads to v/D = (aFli)l(7rR2) = 0.565 (/¿m)"1 for " resting" rat heart muscle (i.e., nonexercising rat).…”

Section: Resultsmentioning

confidence: 99%

Reconsidering the Effect of Local Plasma Convection in a Classical Model of Oxygen Transport in Capillaries

Bos

Hoofd

Oostendorp

1996

Microvascular Research

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Please be advised that this information was generated on 2018-05-09 and may be subject to change. m f c r o v a s c u l a r r e s e a r c h 51, 39-50 (1996) In 1970, Aroesty and Gross investigated the influence of local plasma convection in between two successive red blood cells (RBC) in a capillary on the local oxygen transfer into tissue by combining convectional and diffusional oxygen transport, They concluded that the effect of local plasma convection on oxygen transport in the capillaries was insignificant. Here it is shown that this result was due to their choice of flat oxygen concentration profiles as boundary conditions. In fact, the plasma motion can be of importance when more realistic oxygen concentrations are used as boundary conditions. The fluxes of oxygen through the capillary wall could be up to 50% larger as compared to those of Aroesty and Gross, especially for low hematocrit values and for maximally working muscle. Since the boundary concentrations in the model of the current paper are fixed, chosen not to be influenced by the transport processes, calculations will not show to what extent motion really enhances the oxygen transport, and should be considered as rough indications of the effect of plasma motion. The results in this investigation indicate that in capillaries motion has to be taken into account under conditions of low hematocrit or high RBC velocity.

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Section: Resultsmentioning

confidence: 99%

Reconsidering the Effect of Local Plasma Convection in a Classical Model of Oxygen Transport in Capillaries

Bos

Hoofd

Oostendorp

1996

Microvascular Research

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“…The optimum parameters for oxygen transport by Hb in human red blood cells appear to be a P 50 = 30-50 lM (20-40 mm Hg) at 37°C and association (k¢ O2 ) and dissociation (k O2 ) rate constants ‡ 1 lM (22,35,63,76,93,104,150). The mechanisms that govern O 2 binding have been established in detail and used to design recombinant Hb molecules with P 50 values that range from £ 0.2 to ‡ 200 lM, using both allosteric and active site mutations (14,35,83).…”

Section: Controlling O 2 Affinity and Nodmentioning

confidence: 98%

Development of Recombinant Hemoglobin-Based Oxygen Carriers

Varnado

Mollan

Birukou

et al. 2013

Antioxidants & Redox Signaling

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102

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Significance: The worldwide blood shortage has generated a significant demand for alternatives to whole blood and packed red blood cells for use in transfusion therapy. One such alternative involves the use of acellular recombinant hemoglobin (Hb) as an oxygen carrier. Recent Advances: Large amounts of recombinant human Hb can be expressed and purified from transgenic Escherichia coli. The physiological suitability of this material can be enhanced using protein-engineering strategies to address specific efficacy and toxicity issues. Mutagenesis of Hb can (i) adjust dioxygen affinity over a 100-fold range, (ii) reduce nitric oxide (NO) scavenging over 30-fold without compromising dioxygen binding, (iii) slow the rate of autooxidation, (iv) slow the rate of hemin loss, (v) impede subunit dissociation, and (vi) diminish irreversible subunit denaturation. Recombinant Hb production is potentially unlimited and readily subjected to current good manufacturing practices, but may be restricted by cost. Acellular Hb-based O 2 carriers have superior shelf-life compared to red blood cells, are universally compatible, and provide an alternative for patients for whom no other alternative blood products are available or acceptable. Critical Issues: Remaining objectives include increasing Hb stability, mitigating iron-catalyzed and iron-centered oxidative reactivity, lowering the rate of hemin loss, and lowering the costs of expression and purification. Although many mutations and chemical modifications have been proposed to address these issues, the precise ensemble of mutations has not yet been identified. Future Directions: Future studies are aimed at selecting various combinations of mutations that can reduce NO scavenging, autooxidation, oxidative degradation, and denaturation without compromising O 2 delivery, and then investigating their suitability and safety in vivo. Antioxid. Redox Signal. 18, 2314-2328.

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“…Source code for mitochondria from [21]. [26] rsif.royalsocietypublishing.org J. R. Soc. Interface 14: 20160992…”

Section: Assessment Of Microvascular Oxygen Exchange Capabilitymentioning

confidence: 99%

Image-based modelling of skeletal muscle oxygenation

Zeller‐Plumhoff

Roose

Clough

et al. 2017

J. R. Soc. Interface.

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The supply of oxygen in sufficient quantity is vital for the correct functioning of all organs in the human body, in particular for skeletal muscle during exercise. Disease is often associated with both an inhibition of the microvascular supply capability and is thought to relate to changes in the structure of blood vessel networks. Different methods exist to investigate the influence of the microvascular structure on tissue oxygenation, varying over a range of application areas, i.e. biological in vivo and in vitro experiments, imaging and mathematical modelling. Ideally, all of these methods should be combined within the same framework in order to fully understand the processes involved. This review discusses the mathematical models of skeletal muscle oxygenation currently available that are based upon images taken of the muscle microvasculature in vivo and ex vivo. Imaging systems suitable for capturing the blood vessel networks are discussed and respective contrasting methods presented. The review further informs the association between anatomical characteristics in health and disease. With this review we give the reader a tool to understand and establish the workflow of developing an image-based model of skeletal muscle oxygenation. Finally, we give an outlook for improvements needed for measurements and imaging techniques to adequately investigate the microvascular capability for oxygen exchange.

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A simple model for prediction of oxygen transport rates by flowing blood in large capillaries

Cited by 44 publications

References 12 publications

Reconsidering the Effect of Local Plasma Convection in a Classical Model of Oxygen Transport in Capillaries

Reconsidering the Effect of Local Plasma Convection in a Classical Model of Oxygen Transport in Capillaries

Development of Recombinant Hemoglobin-Based Oxygen Carriers

Image-based modelling of skeletal muscle oxygenation

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