Distribution of oxygen tension on the surface of arterioles, capillaries and venules of brain cortex and in tissue in normoxia: an experimental study on rats

Vovenko, E. P.

doi:10.1007/s004240050825

Cited by 196 publications

(241 citation statements)

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“…Measurements made by Vovenko 20 were used as a reference state in the model, and as such the model predictions are very similar to the data: the model predicted PO 2 values of (70.5, 49.6, 23 The predictions of CBF under both control and vasodilated (SNP) conditions were a good fit to the data ( Figures 3A-B), so would be unlikely to cause significant errors in predictions of PO 2 .…”

Section: Baseline Oxygen Partial Pressurementioning

confidence: 70%

“…3 20 and a steady-state *Krogh cylinder-type model (see Supplementary Methods for more detail and derivation). Then, we calculated adjusted predictions of tissue PO 2 , p % O2;t t ð Þ, to represent the experimental observations, and it is these predictions that are used in the fitting and shown in the figures.…”

Section: Adjusting Tissue Oxygen Partial Pressure Predictionsmentioning

confidence: 99%

“…This makes it possible for PO 2 in the venous compartment to increase without forcing nonphysiologic high values for average tissue PO 2 . 14,19,20 In addition, a new technique developed in this model makes it possible to simulate the dynamics of PO 2 at tissue locations with a wide range of baseline values, rather than being restricted to predicting the average behavior of the tissue. Finally, the model predictions were subjected to an independent validation, since the predictions were consistent with experimental data (vascular PO 2 measurements) not used in the optimization process.…”

Section: Recruitment Of Upstream Oxygenmentioning

confidence: 99%

See 2 more Smart Citations

Extra Permeability is Required to Model Dynamic Oxygen Measurements: Evidence for Functional Recruitment?

Barrett

Suresh

2013

J Cereb Blood Flow Metab

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Neural activation triggers a rapid, focal increase in blood flow and thus oxygen delivery. Local oxygen consumption also increases, although not to the same extent as oxygen delivery. This 'uncoupling' enables a number of widely-used functional neuroimaging techniques; however, the physiologic mechanisms that govern oxygen transport under these conditions remain unclear. Here, we explore this dynamic process using a new mathematical model. Motivated by experimental observations and previous modeling, we hypothesized that functional recruitment of capillaries has an important role during neural activation. Using conventional mechanisms alone, the model predictions were inconsistent with in vivo measurements of oxygen partial pressure. However, dynamically increasing net capillary permeability, a simple description of functional recruitment, led to predictions consistent with the data. Increasing permeability in all vessel types had the same effect, but two alternative mechanisms were unable to produce predictions consistent with the data. These results are further evidence that conventional models of oxygen transport are not sufficient to predict dynamic experimental data. The data and modeling suggest that it is necessary to include a mechanism that dynamically increases net vascular permeability. While the model cannot distinguish between the different possibilities, we speculate that functional recruitment could have this effect in vivo.

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Section: Baseline Oxygen Partial Pressurementioning

confidence: 70%

Section: Adjusting Tissue Oxygen Partial Pressure Predictionsmentioning

confidence: 99%