Studies on the Relationship Between Flow Resistance, Capillary Filtration Coefficient and Regional Blood Volume in the Intestine of the Cat

1963 ◽  
Vol 57 (3) ◽  
pp. 270-283 ◽  
Author(s):  
By Björn Folkow ◽  
Ove Lundgren ◽  
Ingemar Wallentin
Keyword(s):  
Blood Volume ◽  
Flow Resistance ◽  
Filtration Coefficient ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient ◽  
Regional Blood Volume ◽  
The Relationship

Effect of ANP on circulating blood volume

1989 ◽  
Vol 257 (1) ◽  
pp. R127-R131 ◽  
Author(s):  
E. Sugimoto ◽  
K. Shigemi ◽  
T. Okuno ◽  
T. Yawata ◽  
T. Morimoto
Keyword(s):  
Blood Volume ◽  
Venous Pressure ◽  
Filtration Coefficient ◽  
Whole Body ◽  
Control Group ◽  
Peak Reduction ◽  
Circulating Blood Volume ◽  
Capillary Filtration ◽  
Control Value ◽  
Capillary Filtration Coefficient

The effects of rat atrial natriuretic peptide (rANP) on blood volume (BV) were determined by the continuous measurement of BV, mean arterial pressure (MAP), and central venous pressure (CVP). Immediately after a single-bolus injection of rANP-(1-28), 1 nmol/100 g body wt, in conscious rats, BV began to decrease. Peak reduction of -0.22 +/- 0.03 ml/100 g body wt was reached 14.5 min after the injection. Thereafter, BV levels returned gradually to -0.08 +/- 0.03 ml/100 g body wt compared with the control value. In volume expansion experiment, the nephrectomized, anesthetized rats were divided into two groups: the control group, with only a saline infusion, and the ANP group, with an infusion of saline with rANP (1 nmol/100 g body wt). In the ANP group, increases in BV were not as great, and recovery was threefold faster than that of the control group. In the ANP group, the recovery time of BV to the starting control levels was 8.5 min, and the time constant of recovery was 3.6 +/- 0.3 min-1. The control group times were 25 min and 11.5 +/- 0.8 min-1, respectively. The effective vascular compliances were approximately 2.8 ml.mmHg-1.kg body wt-1 in both groups, and the capillary filtration coefficient was 0.47 ml.mmHg-1.min-1.kg body wt-1 in the ANP group and 0.33 ml.mmHg-1.min-1.kg body wt-1 in the control group. Thus the whole body capillary filtration coefficient was 1.5-fold higher in the ANP group than in the control group. This suggests that ANP may increase the permeability of capillaries.

The peculiarities of pulmonary macro- and microhemodynamics changes after treatment with agonists and blockers of cholinoceptors

2021 ◽  
Vol 20 (4) ◽  
pp. 35-44
Author(s):  
Vadim I. Evlakhov ◽  
Ilya Z. Poyassov ◽  
Tatiana P. Berezina
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Vascular Resistance ◽  
Pulmonary Artery Pressure ◽  
Vascular Resistance ◽  
Venous Return ◽  
Filtration Coefficient ◽  
Artery Pressure ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient ◽  
Pulmonary Microcirculation

Background. The pulmonary arterial and venous vessels are innervated by parasympathetic cholinergic nerves. However, the studies, performed on the isolated rings of pulmonary vessels, can not give answer to the question about the role of cholinergic mechanisms in the changes of pulmonary circulation in full measure. Aim. The comparative analysis of the changes of the pulmonary macro- and microhemodynamics after acetylcholine, atropine, pentamine and nitroglycerine treatment. Materials and methods. The study was carried out on the anesthetized rabbits in the condition of intact circulation with the measurement of the pulmonary artery pressure and flow, venae cavae flows, cardiac output, and also on isolated perfused lungs in situ with stabilized pulmonary flow with measurement of the perfused pulmonary artery pressure, capillary hydrostatic pressure, capillary filtration coefficient and calculation of the pulmonary vascular resistance, pre- and postcapillary resistances. Results. In the conditions of intact circulation after acetylcholine, pentamine and nitroglycerine treatment the pulmonary artery pressure and flow decreased, the pulmonary vascular resistance did not change as a result of decreasing of pulmonary artery flow and left atrial pressure due to diminution of venous return and venae cavaе flows. On perfused isolated lungs acetylcholine caused the increasing of pulmonary artery pressure, capillary hydrostatic pressure, pulmonary vascular resistance, pre- and postcapillary resistance and capillary filtration coefficient. After M-blocker atropine treatment the indicated above parameters of pulmonary microcirculation increased, on the contrary, after N-blocker pentamine treatment they decreased. Nitroglycerine infusion caused less decreasing of the parameters of pulmonary microcirculation in comparison with effects of pentamine, but capillary filtration coefficient decreased to a greater extent. These data indicate that nitroglycerine decreases endothelial permeability of pulmonary microvessels. Conclusion. After activation or blockade of cholinergic mechanisms in the condition of intact circulation the calculated parameter of pulmonary vascular resistance is depended from the ratio of the pulmonary artery pressure and flow and left atrial pressure, which are determined by the venous return. The different character of the changes of pulmonary microcirculatory parameters after M-blocker atropine and N-blocker pentamine treatment is evidence of reciprocal relations of M- and N-cholinoceptors in the nervous regulation of the pulmonary microcirculatory bed.

Fetal whole-body interstitial compliance, vascular compliance, and capillary filtration coefficient

1984 ◽  
Vol 247 (5) ◽  
pp. R800-R805 ◽  
Author(s):  
R. A. Brace ◽  
P. S. Gold
Keyword(s):  
Venous Pressure ◽  
Isotonic Saline ◽  
Optimization Techniques ◽  
Filtration Coefficient ◽  
Whole Body ◽  
Fetal Sheep ◽  
Mean Values ◽  
Capillary Filtration ◽  
Vascular Compliance ◽  
Capillary Filtration Coefficient

Fluid movements across the capillary wall were studied in chronically catheterized, near-term fetal sheep. We hemorrhaged 15 fetuses and infused isotonic saline in seven fetuses. The average experimental changes in arterial pressure, venous pressure, and blood volume were then analyzed by using mathematical modeling and parameter optimization techniques to estimate mean values for the average whole-body interstitial and vascular compliances of the fetus and for the average whole-body fetal capillary filtration coefficient. After fetal hemorrhage, interstitial compliance averaged 45 ml X mmHg-1 X kg-1 of fetal weight and vascular compliance averaged 3.0 ml X mmHg-1 X kg-1, whereas the capillary filtration coefficient averaged 0.4 ml X min-1 X mmHg-1 X kg-1. For intravenous saline infusions, interstitial compliance averaged 45 ml X mmHg-1 X kg-1, and vascular compliance averaged 3.5 ml X mmHg-1 X kg-1, whereas the capillary filtration coefficient averaged 0.8 ml X min-1 X mmHg-1 X kg-1. These data suggest that the fetus has a high whole-body interstitial compliance and a high capillary filtration coefficient compared with the adult. In addition, it appears that the fetus has the ability to decrease its vascular compliance and capillary surface area after a fetal hemorrhage.

Capillary filtration coefficient, vascular resistance, and compliance in isolated mouse lungs

1999 ◽  
Vol 87 (4) ◽  
pp. 1421-1427 ◽  
Author(s):  
James C. Parker ◽  
Mark N. Gillespie ◽  
Aubrey E. Taylor ◽  
Sherri L. Martin
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Vascular Function ◽  
Vascular Occlusion ◽  
Filtration Coefficient ◽  
Longitudinal Distribution ◽  
Mouse Lung ◽  
Control Group ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient

Although many recently produced transgenic mice possess gene alterations affecting pulmonary vascular function, there are few baseline measurements of vascular resistance and permeability. Therefore, we excised the lungs of C57/BL6 mice and perfused them with 5% bovine serum albumin in RPMI-1640 culture medium at a nominal flow of 0.5 ml/min and ventilated them with 20% O2-5% CO2-75% N2. The capillary filtration coefficient, a sensitive measurement of hydraulic conductivity, was unchanged over 2 h (0.33 ± 0.03 ml ⋅ min−1 ⋅ cmH2O−1 ⋅ 100 g−1) in a control group ventilated with low peak inflation pressures (PIP) but increased 4.3-fold after high PIP injury. Baseline pulmonary vascular resistance was 6.1 ± 0.4 cmH2O ⋅ ml−1 ⋅ min ⋅ 100 g−1 and was distributed 34% in large arteries, 18% in small arteries, 14% in small veins, and 34% in large veins on the basis of vascular occlusion pressures. Baseline vascular compliance was 5.4 ± 0.3 ml ⋅ cmH2O−1 ⋅ 100 g−1 and decreased significantly with increased vascular pressures. Baseline pulmonary vascular resistance was inversely related to both perfusate flow and microvascular pressure and increased to 202% of baseline after infusion of 10−4 M phenylephrine due to constriction of large arterial and venous segments. Thus isolated mouse lung vascular permeability, vascular resistance, and the longitudinal distribution of vascular resistance are similar to those in other species and respond in a predictable manner to microvascular injury and a vasoconstrictor agent.

Hemoglobin potentiates oxidant injury in isolated rat lungs

1991 ◽  
Vol 260 (6) ◽  
pp. H1980-H1984 ◽  
Author(s):  
A. F. Seibert ◽  
A. E. Taylor ◽  
J. B. Bass ◽  
J. Haynes
Keyword(s):  
Lung Injury ◽  
Thiobarbituric Acid ◽  
Filtration Coefficient ◽  
Oxidant Injury ◽  
Free Iron ◽  
Capillary Filtration ◽  
Rat Lungs ◽  
Capillary Filtration Coefficient ◽  
Isolated Rat

Isolated perfused rat lungs were subjected to oxidant injury induced by tert-butyl hydroperoxide (t-buOOH), which caused a significant increase in capillary permeability as assessed by the change in the capillary filtration coefficient. t-buOOH caused an increase in the change in the capillary filtration coefficient (delta Kfc) of 0.27 +/- 0.05 ml.min.cmH2O-1.100 g lung tissue-1 (mean +/- SE) that was accompanied by an increase in thiobarbituric acid reactive products of lipid peroxidation in the lung perfusate. The addition of hemoglobin to the perfusate potentiated t-buOOH-induced lung injury as evidenced by a significantly greater (P = 0.007) delta Kfc of 0.43 +/- 0.05. t-buOOH also caused hemoglobin to release large quantities of free iron in vitro. The potentiation of t-buOOH-induced lung injury by hemoglobin was prevented by apotransferrin as evidenced by a significant reduction (P = 0.001) in delta Kfc to 0.13 +/- 0.02. No statistically significant (P greater than 0.05) changes in segmental resistances or pulmonary vascular pressures occurred in any of the lungs injured with t-buOOH when compared with time controls. These results demonstrate that t-buOOH causes an oxidant injury in isolated rat lungs that can be potentiated by free iron released from hemoglobin.

Capillary Filtration Coefficient in Upper and Lower Limbs of Healthy Volunteers

1995 ◽  
Vol 88 (s32) ◽  
pp. 20P-21P
Author(s):  
IR Mahy ◽  
AC Shore ◽  
IB Gartside ◽  
J Gamble ◽  
JE Tooke
Keyword(s):  
Healthy Volunteers ◽  
Filtration Coefficient ◽  
Lower Limbs ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient

scholarly journals Comparative Study of Capillary Filtration Coefficient (Kfc) Determination by a Manual and Automatic Perfusion System. Step by Step Technique Review

2019 ◽  
pp. 901-908
Author(s):  
C.C. Bravo-Reyna ◽  
G. Torres-Villalobos ◽  
N. Aguilar-Blas ◽  
J. Frías-Guillén ◽  
J.R. Guerra-Mora
Keyword(s):  
Arterial Pressure ◽  
Pulmonary Arterial Pressure ◽  
Ischemia Reperfusion ◽  
Venous Pressure ◽  
Filtration Coefficient ◽  
Perfusion System ◽  
Gold Standard Method ◽  
Capillary Filtration ◽  
Capillary Filtration Coefficient ◽  
Pulmonary Arterial

The purpose of calculating the capillary filtration coefficient is to experimentally evaluate edema formation in models of pulmonary ischemia-reperfusion injury. For many years, the obtaining of this coefficient implies a series of manual maneuvers during ex-vivo reperfusion of pulmonary arterial pressure, venous pressure and weight, as well as the calculation of the Kfc formula. Through automation, the calculation of capillary filtration coefficient could be easier and more efficient. To describe an automatic method designed in our laboratory to calculating the capillary filtration coefficient and compare with traditional determination of capillary filtration coefficient as gold standard method. An automatic three valve perfusion system was constructed, commanded by a mastery module connected to a graphical user interface. To test its accuracy, cardiopulmonary blocks of Wistar rats were harvested and distributed in manual (n=8) and automated (n=8) capillary filtration coefficient determination groups. Physiological parameters as pulmonary arterial pressure, pulmonary venous pressure, weight and capillary filtration coefficient were obtained. Results: Capillary filtration coefficient, pulmonary arterial pressure, venous arterial pressure shown no statistical significance difference between the groups. The automated perfusion system for obtaining Kfc was standardized and validated, giving reliable results without biases and making the process more efficient in terms of time and personal staff.

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