Effects of Red Cell Spacing and Red Cell Movement Upon Oxygen Release Under Conditions of Maximally Working Skeletal Muscle

Groebe, Karlfried; Thews, G.

doi:10.1007/978-1-4684-5643-1_22

Cited by 44 publications

(40 citation statements)

References 15 publications

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“…Others 29,30,34,37,44 discussed that even in steady-state modeling there was an influence of RBC spacing in the capillary on the efficiency of O 2 transfer from blood to the tissue when the hematocrit was lower than 20%. This is not directly addressed in the current model, but the reduction in oxygen transfer due to the decreased P O 2 within the plasmatic gaps can be well approximated, as far as delivery to the tissue is concerned, by an appropriate reduction in P S cap .…”

Section: Assessment Of the Model's Featuresmentioning

confidence: 99%

“…Other models based on non-cylindrical geometry have been designed or proposed to reflect the morphological and anatomical structures of the specific tissues. [16][17][18]31,34,61 There have been previous studies on simultaneous or dynamic transport and exchange of O 2 and CO 2 in the microcirculation. Hill et al [39][40][41] and Salathe et al 58 studied the kinetics of O 2 and CO 2 exchange through compartmental modeling by accounting for physical and biochemical processes including the acid-base balance.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

Dash

Bassingthwaighte

2006

Ann Biomed Eng

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A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O 2 ) and carbon dioxide (CO 2 ) in the blood-tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O 2 and CO 2 (Bohr and Haldane effects), and since most CO 2 is transported as (bicarbonate) via the CO 2 hydration (buffering) reaction, the transport and exchange of and H + are also simulated along with that of O 2 and CO 2 . Furthermore, the model accounts for the competitive nonlinear binding of O 2 and CO 2 with the hemoglobin inside the red blood cells (nonlinear O 2 -CO 2 interactions, Bohr and Haldane effects), and myoglobin-facilitated transport of O 2 inside the parenchymal cells. The consumption of O 2 through cytochrome-c oxidase reaction inside the parenchymal cells is based on MichaelisMenten kinetics. The corresponding production of CO 2 is determined by respiratory quotient (RQ), depending on the relative consumption of carbohydrate, protein, and fat. The model gives a physiologically realistic description of O 2 transport and metabolism in the microcirculation of the heart. Furthermore, because model solutions for tracer transients and steady states can be computed highly efficiently, this model may be the preferred vehicle for routine data analysis where repetitive solutions and parameter optimization are required, as is the case in PET imaging for estimating myocardial O 2 consumption.

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Section: Assessment Of the Model's Featuresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

Dash

Bassingthwaighte

2006

Ann Biomed Eng

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“…Many models for oxygen transport from blood into tissue have been investigated [1][2][3][4][5][6][7], but they are mainly concerned with steady state and do not allow for transient solutions. Also, the models are over-simplified and neglect certain critical aspects of the oxygen transport system.…”

Section: Introductionmentioning

confidence: 99%

“…Also, the models are over-simplified and neglect certain critical aspects of the oxygen transport system. The models of Federspiel and Sarelius [3], Federspiel and Popel [4] and of Groebe and Thews [7] take into account that hemoglobin comes in discrete packages in the red cell, a factor which Hellums [8] identified in his 1977 paper as being critical at low hematocrits. However, even these studies like those before them give a first approximation only, since they are concerned with steady state situations.…”

Section: Introductionmentioning

confidence: 99%

A computational model of oxygen transport from red blood cells to mitochondria

Beyer¹,

Bassingthwaighte

Deußen

2002

Computer Methods and Programs in Biomedicine

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A computational model of oxygen transport from red blood cells to mitochondria with subsequent reaction to water is presented. This computational model consists of a five region convectiondiffusion-reaction mathematical model which is solved using a standard numerical time-split method. The unique feature of this mathematical model is the treatment of the red blood cells and the plasma as two separate flows. The numerical method is second order accurate overall. This computational model is useful for analyzing residue data from positron emission tomography or data from multiple indicator dilution curves.

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“…When one carefully looks at the concentration gradients that are calculated with models based on diffusion and net convection, it is obvious that the oxygen concentra tion profile at the plasma-tissue and the plasma-RBC interface is curved, with a higher value at the upstream RBC and a lower value at the downstream RBC (Groebe and Thews, 1989;Groebe, 1990;Hoofd, 1992). These curved profiles originate from the particulate nature of blood and the difference in concentration at the up-and downstream RBC is caused by the oxygen loss of the RBCs.…”

Section: Introductionmentioning

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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Effects of Red Cell Spacing and Red Cell Movement Upon Oxygen Release Under Conditions of Maximally Working Skeletal Muscle

Cited by 44 publications

References 15 publications

Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

A computational model of oxygen transport from red blood cells to mitochondria

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

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