“Stringing Together” Capillary Exchange

HAPS Educator ◽  
2019 ◽  
Vol 23 (2) ◽  
pp. 464-468
Author(s):  
Alejandro Quinonez ◽  
Krista Rompolski
Keyword(s):  
Capillary Exchange

Die Atemnotsyndrom-Lunge-Sequestrationsorgan für lösliches Fibrin

1985 ◽  
Vol 05 (03) ◽  
pp. 103-107
Author(s):  
U. Bleyl
Keyword(s):  
Soluble Fibrin ◽  
Pulmonary Failure ◽  
Capillary Exchange ◽  
Fibrin Monomers

SummaryMultifactorial permeability disorders of the alveolo-capillary exchange membranes are one of the main pathophysiologic principles of pulmonary failure in the ARDS. Under the conditions of a generalized activation of coagulation these permeability disorders result in a leakage of circulating fibrin monomers and oligomers into the pulmonary interstitia and alveoli, even before the monomers and oligomers may precipitate intravascularly to disseminated microthrombi. Under the patho-physiologic conditions of an ARDS the lungs thus become an organ of excretion for soluble, intravascularly circulating fibrin monomers and oligomers, an organ of sequestration for soluble fibrin.

Effects of flow heterogeneity on the measurement of capillary exchange in the lung

1995 ◽  
Vol 79 (5) ◽  
pp. 1449-1460 ◽  
Author(s):  
S. D. Caruthers ◽  
T. R. Harris ◽  
K. A. Overholser ◽  
N. A. Pou ◽  
R. E. Parker
Keyword(s):  
Effective Diffusivity ◽  
Relative Dispersion ◽  
Flow Heterogeneity ◽  
Homogeneous Flow ◽  
Capillary Recruitment ◽  
Flow Models ◽  
Capillary Exchange ◽  
Variable Recruitment ◽  
Area Product ◽  
Recruitment Model

The effects of flow heterogeneity on the measurement of transcapillary escape of small molecules for perfused in situ sheep lungs were evaluated. Lungs were studied at five flows (1.5–5.0 l/min) ranging from zone 1 to zone 3 conditions. At each flow, multiple indicator-dilution curves were collected using 14C-labeled urea (U) or butanediol (B) as the diffusing tracer, and radiolabeled 15-microns microspheres were injected. The lungs were removed, dried, sectioned, weighed, and counted for microsphere radioactivity. Flow heterogeneity expressed as relative dispersion, decreased with increasing flow, from 0.838 +/- 0.179 (mean +/- SD, n = 8) to 0.447 +/- 0.119 (n = 6). We applied homogeneous flow models of capillary exchange to compute permeability-surface area product (PS) and a related parameter, D1/2S, for diffusing tracers. (D is effective diffusivity of capillary exchange.) PS and D1/2S increased to a maximum with increasing flow, but the ratio of D1/2SU to D1/2SB remained constant. A new model incorporating flow heterogeneity and recruitment (the variable recruitment model) was used. The variable recruitment model described the effects of flow on capillary recruitment, but incorporating heterogeneity into the computation did not alter D1/2S values from those computed assuming homogeneous flow.

A Model of Nitric Oxide Capillary Exchange

2003 ◽  
Vol 10 (6) ◽  
pp. 479-495 ◽  
Author(s):  
NIKOLAOS M. TSOUKIAS ◽  
ALEKSANDER S. POPEL
Keyword(s):  
Nitric Oxide ◽  
Capillary Exchange

A model for capillary exchange

1966 ◽  
Vol 210 (6) ◽  
pp. 1299-1303 ◽  
Author(s):  
JA Johnson ◽  
TA Wilson
Keyword(s):  
Capillary Exchange

Vascular transport capacity of hindlimb muscles of exercise-trained rats

1987 ◽  
Vol 62 (2) ◽  
pp. 438-443 ◽  
Author(s):  
M. H. Laughlin ◽  
J. Ripperger
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Exchange Capacity ◽  
Transport Capacity ◽  
Diffusion Capacity ◽  
Capillary Filtration ◽  
Vascular Transport ◽  
Flow Capacity ◽  
Vascular Flow ◽  
Regional Flow ◽  
Capillary Exchange

The purpose of this study was to determine whether chronic exercise training is associated with increased vascular flow capacity and capillary exchange capacity in skeletal muscles. One group of male Sprague-Dawley rats was cage confined for a period of 13'17 wk (sedentary control, C) and a second was trained for 1 h/day at a speed of 30 m/min up a 5 degrees incline for 13–17 wk (exercise trained, ET). Studies were conducted with maximally dilated (papaverine) isolated hindquarters of 13 C rats and 10 ET rats perfused with Tyrode's solution containing 5% albumin. Vascular flow capacity was estimated by measuring total and regional flows at three to five different perfusion pressures. Capillary exchange capacity was estimated by measuring maximal capillary filtration coefficients and capillary diffusion capacity for 51Cr-ethylenediaminetetraacetic acid (51Cr-EDTA). The efficacy of the training was shown by significant increases in succinate dehydrogenase activities of the vastus intermedius muscle. Total hindquarter flow capacity was 50% higher in the ET rats. Regional flow data indicated that the higher total flow was due to increased muscle flow (85%), with the high-oxidative muscle tissue having the greatest increases (e.g., 200% increase in red gastrocnemius muscle). The maximal capillary diffusion capacity values for the ET rats were 70% greater than control values. However, the capillary filtration capacity values of the C and ET rats were not different. We conclude that the vascular transport capacity of the high-oxidative areas of extensor muscles is increased by endurance training.

beta-Adrenergic dilator effects in consecutive vascular sections of skeletal muscle

1982 ◽  
Vol 243 (5) ◽  
pp. H819-H829
Author(s):  
J. Lundvall ◽  
J. Hillman ◽  
D. Gustafsson
Keyword(s):  
Skeletal Muscle ◽  
Beta Adrenergic ◽  
Resistance Function ◽  
Vasoconstrictor Response ◽  
Resistance Vessels ◽  
Capillary Exchange ◽  
Regional Vascular Resistance ◽  
Hydrodynamic Exchange ◽  
Exchange Function ◽  
Adrenergic Effects

Humoral and neurogenic beta-adrenergic dilatation that influenced the resistance function, the capillary exchange function, and to some extent the capacitance function was demonstrated in the vascular bed of cat skeletal muscle. The beta-adrenergic effects were mainly confined to the microcirculation, causing dilatation of the precapillary sphincters and the resistance vessels of small calibre. The microcirculatory effects were pronounced in response to epinephrine, but blood-borne and nerve-released norepinephrine also evoked marked effects. The beta-adrenergic inhibition of vascular tone in the microcirculation may serve in the intact organism to improve tissue nutrition by facilitating capillary diffusion exchange. It further seems to regulate transcapillary hydrodynamic exchange, partly by controlling the precapillary sphincters and the capillary hydrostatic pressure. The blood-borne catecholamines, especially epinephrine, also markedly affected total regional vascular resistance and thereby blood flow by dilator interaction with the concomitant alpha-adrenergic vasoconstrictor response.

Intertissue diffusion effect for inert fat-soluble gases

1965 ◽  
Vol 20 (4) ◽  
pp. 621-627 ◽  
Author(s):  
William Perl ◽  
Herbert Rackow ◽  
Ernest Salanitre ◽  
Gerald L. Wolf ◽  
Robert M. Epstein
Keyword(s):  
Adipose Tissue ◽  
Gas Exchange ◽  
Human Subjects ◽  
Compartment Model ◽  
Inert Gases ◽  
Gas Uptake ◽  
Model Generalization ◽  
Capillary Exchange ◽  
Uptake Measurement ◽  
Kinetics Of

An approximately constant 5% difference in alveolar concentration of nitrous oxide and cyclopropane exists when these two gases are administered simultaneously to human subjects. This difference in uptake cannot be fully explained within the traditional framework of a perfusion-limited, multi-compartment model of inert gas exchange. It is proposed that this difference reflects direct diffusion from lean to neighboring adipose tissue through distances of the order of 1 mm. The diffusional rate of cyclopropane uptake into adipose tissue is initially large relative to perfusional uptake. The two rates eventually become and remain comparable as both decrease to zero. Implications of these results for deduction of blood flow to body adipose tissue by gas uptake measurement, and for utilization of capillary exchange surface by fat-soluble gases in adipose tissue are discussed. compartment model generalization; gas uptake in body; inert, fat-soluble gas uptake; kinetics of gas exchange in body; body uptake of inert gases; fat-soluble gas uptake; distribution kinetics of gases in body Submitted on February 3, 1964

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