Effect of small doses of 5-hydroxytryptamine (serotonin) on pulmonary circulation in the closed-chest dog

1959 ◽  
Vol 197 (5) ◽  
pp. 963-967 ◽  
Author(s):  
John T. Shepherd ◽  
David E. Donald ◽  
Erland Linder ◽  
H. J. C. Swan
Keyword(s):  
Pulmonary Artery ◽  
Pulmonary Blood Flow ◽  
Pulmonary Veins ◽  
Pulmonary Vessels ◽  
Isolated Perfused Lung ◽  
Small Doses ◽  
Perfused Lung ◽  
Anesthetized Dogs ◽  
Flow Through ◽  
The Difference

5-Hydroxytryptamine (serotonin) was infused into anesthetized dogs at a rate of 20 µg/kg/min. In nine sets of observations on three dogs the increase in the difference of pressure between the pulmonary artery and the left atrium, which averaged 55%, consistently exceeded the increase in pulmonary blood flow, which averaged 16%. 5-HT therefore is a potent constrictor of pulmonary vessels, even in small concentrations. No changes in the pulmonary-artery wedge and pulmonary-vein pressures were detected during the infusions of 5-HT, nor was there any change in the volume of blood between the pulmonary artery and the root of the aorta. With this dose of 5-HT the principal site of the increased resistance to flow through the lungs appeared to be in the precapillary vessels. In the isolated perfused lung, moderate constriction of pulmonary veins also was produced by large doses of 5-HT.

Unequal right and left ventricular ejection with ectopic beats

1962 ◽  
Vol 203 (6) ◽  
pp. 1141-1144 ◽  
Author(s):  
Jay M. Levy ◽  
Emmanuel Mesel ◽  
Abraham M. Rudolph
Keyword(s):  
Pulmonary Artery ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Pulmonary Flow ◽  
Anesthetized Dogs ◽  
Ectopic Beats ◽  
The Difference ◽  
The Right ◽  
Ventricular Depolarization

Simultaneous right and left ventricular stroke volumes were measured with electromagnetic flow probes in open-chest, anesthetized dogs. Atrial ectopic beats with normal ventricular depolarization produced differences between right and left ventricular stroke output, although the right and left ventricular pressures were proportionately reduced to an equal extent. This imbalance in volume ejected was a result of the differences in diastolic level, related to peak systolic pressure, in the aorta compared with pulmonary artery. With ventricular ectopic beats, the stimulated ventricle failed to develop the same percentage of control pressure as did the contralateral ventricle. The difference between aortic and pulmonary flow was thus less marked with right ventricular ectopic beats, and exaggerated with left ventricular ectopic beats.

Adrenomedullin activity in chronically hypoxic rat lungs

1996 ◽  
Vol 271 (2) ◽  
pp. H622-H629 ◽  
Author(s):  
L. Zhao ◽  
L. A. Brown ◽  
A. A. Owji ◽  
D. J. Nunez ◽  
D. M. Smith ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Mrna Levels ◽  
Rat Lung ◽  
Artery Pressure ◽  
Isolated Perfused Lung ◽  
Calcitonin Gene ◽  
Perfused Lung ◽  
Hypotensive Response

Adrenomedullin (AM) is a novel vasodilator with structural similarities to calcitonin gene-related peptide (CGRP). This study investigated AM activity in the rat lung during hypoxia-induced pulmonary hypertension. Both rat AM (0.2-10 nmol) and alpha-CGRP (0.2-2 nmol) produced dose-related reductions in pulmonary artery pressure in the isolated perfused lung ventilated with 2% O2. Pretreatment with alpha-CGRP, which demonstrated tachyphylaxis, or its antagonist, CGRP-(8–37), reduced the hypotensive response to AM, suggesting that part of the response to AM is mediated by CGRP receptors. 125I-labeled AM and 125I-labeled CGRP binding was significantly increased in lung membranes from 7-day hypoxic animals (AM from 1.94 +/- 0.3 to 3.36 +/- 0.4 and CGRP from 0.06 +/- 0.01 to 0.12 +/- 0.02 pmol/mg protein), with no change in dissociation constant. Moreover, the hypotensive response to both peptides was increased in the lungs of 7-day hypoxic rats. There was no significant change in lung immunoreactive AM concentrations (hypoxic 5.04 +/- 0.48 vs. control 6.28 +/- 0.76 pmol/g wet wt of tissue) or steady-state AM mRNA levels in 7-day hypoxic rats. Nonetheless, AM may be useful for the acute pharmacological manipulation of pulmonary artery pressure in hypoxia-induced pulmonary hypertension.

scholarly journals Transbronchial Cryobiopsies in the Evaluation of Lung Allografts: Do the Benefits Outweigh the Risks?

2015 ◽  
Vol 140 (4) ◽  
pp. 303-311 ◽  
Author(s):  
Anja C. Roden ◽  
Ryan M. Kern ◽  
Marie Christine Aubry ◽  
Sarah M. Jenkins ◽  
Eunhee S. Yi ◽  
...  
Keyword(s):  
Mayo Clinic ◽  
Medical Records ◽  
Pulmonary Veins ◽  
Small Airways ◽  
Volume Number ◽  
Pulmonary Vessels ◽  
Specimen Volume ◽  
Significant Difference ◽  
Histopathologic Evaluation ◽  
The Difference

Transbronchial cryobiopsy technique yields larger biopsies with enhanced quality. The benefits and safety of cryobiopsies have not been thoroughly studied in lung allografts.Context.— To compare size, quality, reproducibility of interpretation of rejection and complications of cryobiopsies with those of conventional biopsies from lung allografts.Objective.— All cryobiopsies (March 2014–January 2015) of lung allografts performed at Mayo Clinic, Rochester, and medical records were reviewed. For comparison, conventional biopsies from the same patient or, if unavailable, from a random patient, were selected. Two pathologists blinded to outcome reviewed all biopsies. Specimen volume, number of alveoli, small airways, and pulmonary vessels were counted and statistically compared.Design.— Fifty-four biopsies (27 cryobiopsies) from 18 patients (11 men) were reviewed. A median of 3 (range, 2–5) and 10 (range, 6–12) specimens were obtained with cryobiopsies and conventional biopsies, respectively. Cryobiopsies were larger and contained more alveoli (P < .001, both) and small airways (P = .04). Conventional biopsies showed more fresh alveolar hemorrhage (procedural) and crush artifact/atelectasis (P < .001, both). Cryobiopsies contained more pulmonary veins and venules (P < .001). There was no significant difference between the types of biopsies with respect to the reviewers' agreement on grades of rejection. Complications were more frequent in the cryobiopsy group, though the difference was not statistically significant.Results.— Cryobiopsies of lung allografts are larger and have less artifact. However, complications occur and should be considered. Three cryobiopsy specimens appear sufficient for histopathologic evaluation of lung allografts.Conclusions.—

MECHANISMS OF HEMOCONCENTRATION IN THE DOG DURING ACUTE ENDRIN INSECTICIDE POISONING

1965 ◽  
Vol 43 (5) ◽  
pp. 793-800 ◽  
Author(s):  
Thomas E. Emerson Jr.
Keyword(s):  
Pulmonary Artery ◽  
Venous Return ◽  
Venous Pressure ◽  
Lung Weight ◽  
Vascular Volume ◽  
Isolated Perfused Lung ◽  
Blood Ph ◽  
Early Increase ◽  
Perfused Lung ◽  
Low Levels

Hemoconcentration following intravenous administration of the chlorinated hydrocarbon insecticide endrin was investigated in sham-operated, splenectomized, and abdominal-eviscerated dogs. Isolated perfused lung preparations and those in which total venous return to the heart was monitored were also utilized. By 30 minutes after endrin the hematocrit had increased 14% in sham-operated animals but only 8% in splenectomized and eviscerated dogs. Blood pH fell to low levels in all groups. Pulmonary artery pressure increased in the constant flow perfused lungs after endrin; an early increase preceded a loss of lung weight. Pulmonary vascular resistance and left atrial and pulmonary artery pressures increased after endrin in the venous return studies. Hemoconcentration appears to result in part from addition of cell-rich blood from the spleen, and an increase in mean corpuscular volume secondary to the severe acidemia as observed in several experiments may also be involved. Loss of plasma fluid in the hepatosplanchnic area does not seem to occur, but pulmonary venous pressure was elevated, and loss of vascular volume from the lungs cannot be excluded.

Cardiovascular adjustments in dogs during continuous pressure breathing

1960 ◽  
Vol 15 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Claude Lenfant ◽  
Barbara J. Howell
Keyword(s):  
Cardiac Output ◽  
Pulmonary Artery ◽  
Vena Cava ◽  
Pulmonary Vessels ◽  
Pulmonary Flow ◽  
Airway Pressures ◽  
Anesthetized Dogs ◽  
Pressure Changes ◽  
Flow Resistances

Pressure changes in the pulmonary artery and vein, thoracic vena cava, aorta and intrapleural space as well as the cardiac output were measured in anesthetized dogs subjected to continuous airway pressures varying between -25 to +25 cm H2O. Pulmonary and systemic resistances were calculated. During positive airway pressures the pulmonary artery, vein and vena cava pressures approximately paralleled changes in intrapleural pressures. Cardiac output and aorta pressures decreased; systemic and pulmonary flow resistances markedly increased. During negative airway pressures the pulmonary vessels and vena cava pressures decreased but no longer paralleled the changes in intrapleural pressures. It is assumed that these vessels reached their limit of distensibility. While aortic pressures decreased, cardiac output, systemic and pulmonary resistances remained essentially unchanged. Submitted on January 14, 1960

Pulmonary Embolization in the Dog: Its Effects on Blood Coagulation and on Pulmonary Artery Pressures

1961 ◽  
Vol 06 (01) ◽  
pp. 025-036 ◽  
Author(s):  
James W. Hampton ◽  
William E. Jaques ◽  
Robert M. Bird ◽  
David M. Selby
Keyword(s):  
Pulmonary Hypertension ◽  
Particulate Matter ◽  
Pulmonary Artery ◽  
Amniotic Fluid ◽  
Blood Coagulation ◽  
Glass Beads ◽  
Pulmonary Vessels ◽  
Pulmonary Embolization ◽  
Biological Nature

Summary1. Infusions containing particulate matter, viz. whole amniotic fluid, amniotic fluid sediment, and glass beads, produce in dogs changes in both early and late phases of the clotting reaction. These changes are associated with the development of pulmonary hypertension.2. When dogs were given an active fibrinolysin followed by an infusion of whole amniotic fluid, the alterations in the clotting mechanism were either delayed or did not appear. No pulmonary hypertension developed in these animals.3. We infer that infusions containing particulate matter will produce in dogs both pulmonary hypertension and changes in the clotting mechanism. Although these are independent changes, both are as closely related to the damage to the pulmonary vessels as they are to the biological nature of the infusions.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

Pulmonary diffusion in the dog lung

1962 ◽  
Vol 17 (6) ◽  
pp. 885-892 ◽  
Author(s):  
Albert H. Niden ◽  
Charles Mittman ◽  
Benjamin Burrows
Keyword(s):  
Carbon Monoxide ◽  
Pulmonary Artery ◽  
Experimental Animal ◽  
Venous Blood ◽  
Whole Body ◽  
Mixed Venous Blood ◽  
Pulmonary Diffusion ◽  
Perfused Lung ◽  
Pulmonary Arterial ◽  
Mixed Venous

Methods have been presented for assessing pulmonary diffusion by the “equilibration technique” in the experimental intact dog and perfused lung while controlling ventilation with a whole body respirator. No significant change in diffusion of carbon monoxide was noted between open and closed chest anesthetized animals, with duration of anesthesia in the intact dog, or with duration of perfusion of the isolated dog's lung. There was no demonstrable difference in diffusion when arterialized blood was used as the perfusate in place of mixed venous blood in the lung perfusions suggesting that within the range studied the Po2, Pco2, and pH of pulmonary artery blood does not directly affect the diffusion of carbon monoxide. Retrograde perfusions of dogs' lungs did not significantly alter diffusion, suggesting that pulmonary venous resistance was not significantly lower than pulmonary arterial resistance in the perfused dog lung at the flows and pressures studied. The equilibration technique for measuring pulmonary diffusion and assessing the uniformity of diffusion was well suited to the study of pulmonary diffusing characteristics in the experimental animal. Submitted on January 8, 1962

Control of breathing in anesthetized dogs by a left-heart baroreflex

1986 ◽  
Vol 61 (6) ◽  
pp. 2095-2101 ◽  
Author(s):  
T. C. Lloyd
Keyword(s):  
Pulmonary Veins ◽  
Vagal Afferents ◽  
Low Flow ◽  
Base Line ◽  
Left Heart ◽  
Breathing Frequency ◽  
Autonomic Ganglion ◽  
Anesthetized Dogs ◽  
The Right ◽  
Vagal Cooling

Anesthetized open-chest dogs on cardiopulmonary bypass were used to test the hypothesis that breathing reflexly responds to distension of the left-heart chambers. Bypass perfusion withdrew systemic flow from the right atrium and returned it to the aorta after gas exchange. Ventricles were fibrillated. The left heart was isolated by tying all pulmonary veins, and it was perfused separately at low flow admitted through one pulmonary vein and withdrawn from the ventricle. Left-heart pressure was intermittently raised abruptly from a nominal base line of 0 by partial occlusion of outflow. Pressures from approximately 10 to 50 cmH2O caused proportional increases in breathing frequency and decreases in expiratory and inspiratory times. Changes occurred immediately, reached a plateau within approximately 20 s, and were sustained for periods of observation as long as 3 min. Recovery to base line followed stimulus removal. Vagal cooling to 8 degrees C prevented responses, but autonomic ganglion blockade with hexamethonium had no effect. I conclude that breathing may be stimulated by left-heart distension and that this is mediated by large myelinated vagal afferents.

Basic determinants of epicardial transudation

1997 ◽  
Vol 273 (3) ◽  
pp. H1408-H1414 ◽  
Author(s):  
R. H. Stewart ◽  
D. A. Rohn ◽  
S. J. Allen ◽  
G. A. Laine
Keyword(s):  
Reflection Coefficient ◽  
Coronary Sinus ◽  
Myocardial Edema ◽  
Hydraulic Conductance ◽  
Linear Increase ◽  
Left Ventricular ◽  
Edema Formation ◽  
Anesthetized Dogs ◽  
The Difference ◽  
Osmotic Reflection Coefficient

Myocardial edema formation, which has been shown to compromise cardiac function, and increased epicardial transudation (pericardial effusion) have been shown to occur after elevation of myocardial venous and lymphatic outflow pressures. The purposes of this study were to estimate the hydraulic conductance and osmotic reflection coefficient for the epicardium and to determine the effect of coronary sinus hypertension and cardiac lymphatic obstruction on epicardial fluid flux (JV,e/Ae). A Plexiglas hemispheric capsule was attached to the left ventricular epicardial surface of anesthetized dogs. JV,e/Ae was determined over 30-min periods for three intracapsular pressures (-5, -15, and -25 mmHg) and two intracapsular solutions exerting colloid osmotic pressures of 7.0 and 2.0 mmHg. Hydraulic conductance was estimated to be 3.7 +/- 0.5 microliters.h-1.cm-2.mmHg-1. An osmotic reflection coefficient of 0.9 was calculated from the difference in JV,e/Ae of 16.5 +/- 8.4 microliters.h-1.cm-2 between the two solutions. Graded coronary sinus hypertension induced a linear increase in JV,e/Ae, which was significantly greater in dogs without cardiac lymphatic occlusion than in those with occlusion.

Sign in / Sign up

Export Citation Format

Share Document