Origin, distribution, and blood flow of bronchial circulation in anesthetized sheep

1982 ◽  
Vol 53 (1) ◽  
pp. 272-279 ◽  
Author(s):  
M. G. Magno ◽  
A. P. Fishman
Keyword(s):  
Blood Flow ◽  
Artery Blood Flow ◽  
Bronchial Circulation ◽  
India Ink ◽  
Apical Lobe ◽  
Aortic Blood Pressure ◽  
The Right ◽  
Artery Flow ◽  
Systemic Arteries

This anatomical-physiological study was undertaken to determine the suitability of the sheep for studies of the bronchial circulation. We designated the terminal portion of the bronchoesophageal artery, which runs to the trachea at the carina, as the “carinal” artery. Postmortem injections of india ink (9 sheep) and Batson's solution (4 sheep) into the carinal artery showed that the carinal artery supplied the bronchi of all lobes except the right apical lobe; the mass of the lung containing bronchi perfused represented 88 +/- 1% of total lung mass. Communications were also found between branches of the carinal artery and branches of the systemic arteries supplying the visceral pleura. In three of six sheep, the carinal artery wedge pressure measured in vivo indicated that patent collaterals were present, but that their incidence is variable. In additional postmortem casts of the aorta made in four sheep after ligation of the carinal artery, the bronchial microcirculation was not entered by the perfusing medium. These data indicate that the collaterals do not contribute significantly to bronchial blood flow and that the carinal artery is the major source of bronchial blood flow in the sheep. In 19 sheep, carinal artery flow, measured electromagnetically, was 0.46 +2- 0.09 ml . min-1 . kg body wt-1. Bronchial blood flow normalized for the weight of the lobes in which bronchi perfused by the carinal artery were located was 3.97 +/- 0.48 ml . min-1 . 100 g lung-1 (n = 11); carinal artery blood flow was 0.39 +/- 0.03% of cardiac output (n = 5). During the 90 min of observation, at normal aortic blood pressure (103 +/- 3.4 Torr), carinal artery blood flow was stable. In conclusion, determination of carinal artery blood flow affords a reliable approach to the bronchial circulation in the sheep.

scholarly journals Dynamic anatomical study of cardiac shunting in crocodiles using high-resolution angioscopy

1996 ◽  
Vol 199 (2) ◽  
pp. 359-365 ◽  
Author(s):  
M Axelsson ◽  
C E Franklin ◽  
C O Löfman ◽  
S Nilsson ◽  
G C Grigg
Keyword(s):  
High Resolution ◽  
Connective Tissue ◽  
Right Ventricle ◽  
Anatomical Study ◽  
Systemic Circulation ◽  
Outflow Tract ◽  
Aortic Valves ◽  
Aortic Blood Pressure ◽  
The Right

Prolonged submergence imposes special demands on the cardiovascular system. Unlike the situation in diving birds and mammals, crocodilians have the ability to shunt blood away from the lungs, despite having an anatomically divided ventricle. This remarkable cardiovascular flexibility is due in part to three anatomical peculiarities: (1) an 'extra' aorta (the left aorta) that leaves the right ventricle and allows the blood from the right ventricle to take an alternative route into the systemic circulation instead of going to the lungs; (2) the foramen of Panizza, an aperture that connects the right and left aortas at their base immediately outside the ventricle; and (3) a set of connective tissue outpushings in the pulmonary outflow tract in the right ventricle. Using high-resolution angioscopy, we have studied these structures in the beating crocodile heart and correlated their movements with in vivo pressure and flow recordings. The connective tissue outpushings in the pulmonary outflow tract represent an active mechanism used to restrict blood flow into the lungs, thus creating one of the conditions required for a right-to-left shunt. We observed that the foramen of Panizza was obstructed by the medial cusp of the right aortic valve during most of systole, effectively differentiating the left and right aortic blood pressure. During diastole, however, the foramen remained open, allowing pressure equilibration between the two aortas. Contrary to current theories, we found that the left aortic valves were unable to cover the foramen of Panizza during any part of the cardiac cycle, supporting the reversed foramen flow hypothesis. This would ensure a supply of blood to the coronary and cephalic circulation during a complete shut-down of the left side of the heart, such as might occur during prolonged submergence.

scholarly journals Measuring peripheral resistance and conduit arterial structure in humans using Doppler ultrasound

2005 ◽  
Vol 98 (6) ◽  
pp. 2311-2315 ◽  
Author(s):  
Louise H. Naylor ◽  
Cara J. Weisbrod ◽  
Gerry O'Driscoll ◽  
Daniel J. Green
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Peripheral Resistance ◽  
Artery Blood Flow ◽  
Brachial Artery Diameter ◽  
Resistance Vessel ◽  
Conduit Artery ◽  
Significant Difference ◽  
Vessel Structure

The purpose of this study was to establish valid indexes of conduit and resistance vessel structure in humans by using edge detection and wall tracking of high-resolution B-mode arterial ultrasound images, combined with synchronized Doppler waveform envelope analysis, to calculate conduit artery blood flow and diameter continuously across the cardiac cycle. Nine subjects aged 36.7 (9.2) yr underwent, on separate days, assessment of brachial artery blood flow and diameter response to 5-, 10-, and 15-min periods of forearm ischemia in the presence and absence of combined sublingual glyceryl trinitrate (GTN) administration. Two further sessions examined responses to ischemic exercise, one in combination with GTN. The peak brachial artery diameter was observed in response to the combination of ischemic exercise and GTN; a significant difference existed between resting brachial artery diameter and peak brachial artery diameter, indicating that resting diameter may be a poor measure of conduit vessel structure in vivo. Peak brachial artery flow was also observed in response to a combination of forearm ischemia exercise and GTN administration, the response being greater than that induced by periods of ischemia, GTN, or ischemic exercise alone. These data indicate that noninvasive indexes of conduit and resistance vessel structure can be simultaneously determined in vivo in response to a single, brief, stimulus and that caution should be applied in using resting arterial diameter as a surrogate measure of conduit artery structure in vivo.

scholarly journals 1050: Cross-modality, in-vivo validation of 4D-Flow MRI evaluation of uterine artery blood flow in human pregnancy

2019 ◽  
Vol 220 (1) ◽  
pp. S673-S674
Author(s):  
Nadav Schwartz ◽  
Eileen Hwuang ◽  
Ana Rodriguez-Soto ◽  
Felix Wehrli ◽  
Marta Vidorreta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Uterine Artery ◽  
Artery Blood Flow ◽  
4D Flow Mri ◽  
4D Flow ◽  
Human Pregnancy ◽  
Flow Mri ◽  
Mri Evaluation ◽  
In Vivo Validation

Renal 131I-hippurate clearance overestimates true renal blood flow in the instrumented conscious dog

1996 ◽  
Vol 271 (2) ◽  
pp. F269-F274 ◽  
Author(s):  
C. A. Visscher ◽  
D. De Zeeuw ◽  
G. Navis ◽  
A. K. Van Zanten ◽  
P. E. De Jong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Artery Blood Flow ◽  
Venous Outflow ◽  
Flow Probe ◽  
The Difference ◽  
Probe Calibration ◽  
Clearance Technique ◽  
Venous Plasma

We evaluated renal 131I-hippurate clearance (ERPFhip) as a measure of renal blood flow (RBF) in chronically instrumented conscious dogs. When adjusted for renal hippurate extraction (Ehip, 0.77 +/- 0.01) and hematocrit (Hct, 39.7 +/- 1%), calculated RBFhip (656 +/- 37 ml/min) markedly exceeded renal blood flow measured with renal artery blood flow probes (RBFprobe, 433 +/- 27 ml/min). The discrepancy could not be explained by flow probe calibration, because in vivo comparison of flow probe values with renal venous outflow showed only a slight underestimation of renal blood flow (slope 0.93, 95% confidence interval 0.89-0.97). Redistribution of hippurate from erythrocytes into renal venous plasma during or shortly after blood sampling led to an underestimation of Ehip by 4 +/- 1% and thus could only explain a small part of the difference. Extrarenal hippurate clearance was excluded, because the amount of 131I-hippurate cleared from plasma equaled that appearing in the urine (303 +/- 17 and 307 +/- 17 ml/min). Applying these corrections, we found that RBFhip still exceeded RBFprobe by 37 +/- 3%. These data indicate that renal blood flow measured by the hippurate clearance technique markedly overestimates true renal blood flow. Because other errors were excluded, a combination of sampling of nonrenal blood and intrarenal hippurate extraction from erythrocytes might play a role.

C5a-induced myocardial ischemia: role for CD18-dependent PMN localization and PMN-platelet interactions

1993 ◽  
Vol 265 (5) ◽  
pp. H1750-H1761 ◽  
Author(s):  
M. P. Fletcher ◽  
G. L. Stahl ◽  
J. C. Longhurst
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Myocardial Ischemia ◽  
Myocardial Segment ◽  
Artery Blood Flow ◽  
Arterial Blood ◽  
Pmn Functions ◽  
Dependent Mechanism

Intracoronary C5a in swine decreases coronary blood flow and regional myocardial segment shortening, responses mediated by thromboxane (Tx) A2-induced coronary vasoconstriction and intramyocardial trapping of granulocytes (PMNs). We sought to determine the origin of TxA2 and to investigate the role of CD18-dependent PMN function by utilizing an anti-CD18 monoclonal antibody, IB4. Isolated C5a-stimulated PMNs or platelets did not produce TxB2. However, together, C5a-stimulated PMNs and platelets produced TxB2. IB4 bound porcine PMN surface CD18 and blocked C5a-induced PMN functions. In vivo, IB4 loading (2 mg/kg) transiently decreased arterial blood pressure and circulating platelet counts in six of nine animals (390 +/- 31 vs. 176 +/- 41 X 10(6)/ml, control vs. IB4; P < 0.002) and significantly ameliorated C5a-induced decreases in coronary venous PMN count (-4.1 +/- 0.6 vs. -1.4 +/- 0.8 X 10(6) cells/ml), coronary artery blood flow (-10 +/- 1 vs. -4 +/- 1 ml/min), and segment shortening (-15 +/- 2 vs. -8 +/- 2%, C5a vs. C5a + IB4). We conclude that 1) production of TxB2 in response to C5a is mediated by a PMN-platelet interaction, 2) IB4 functionally blocks CD18 on porcine PMNs, and 3) C5a-induced myocardial PMN extraction is mediated, in part, by a CD18-dependent mechanism. These results suggest that PMN-platelet interactions and CD18-dependent PMN extraction are important in C5a-induced myocardial ischemia.

Inhibiting NOS blocks microvascular recruitment and blunts muscle glucose uptake in response to insulin

2003 ◽  
Vol 285 (1) ◽  
pp. E123-E129 ◽  
Author(s):  
M. A. Vincent ◽  
E. J. Barrett ◽  
J. R. Lindner ◽  
M. G. Clark ◽  
S. Rattigan
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Glucose Uptake ◽  
Glucose Disposal ◽  
Total Blood ◽  
Artery Flow ◽  
Microvascular Recruitment ◽  
Total Blood Flow

We examined the effects of inhibiting nitric oxide synthase with Nω-nitro-l-arginine-methyl ester (l-NAME) on total hindlimb blood flow, muscle microvascular recruitment, and hindlimb glucose uptake during euglycemic hyperinsulinemia in vivo in the rat. We used two independent methods to measure microvascular perfusion. In one group of animals, microvascular recruitment was measured using the metabolism of exogenously infused 1-methylxanthine (1-MX), and in a second group contrast-enhanced ultrasound (CEU) was used. Limb glucose uptake was measured by arterial-venous concentration differences after 2 h of insulin infusion. Saline alone did not alter femoral artery flow, glucose uptake, or 1-MX metabolism. Insulin (10 mU·min-1·kg-1) significantly increased hindlimb total blood flow (0.69 ± 0.02 to 1.22 ± 0.11 ml/min, P < 0.05), glucose uptake (0.27 ± 0.05 to 0.95 ± 0.08 μmol/min, P < 0.05), 1-MX uptake (5.0 ± 0.5 to 8.5 ± 1.0 nmol/min, P < 0.05), and skeletal muscle microvascular volume measured by CEU (10.0 ± 1.6 to 15.0 ± 1.2 video intensity units, P < 0.05). Addition of l-NAME to insulin completely blocked the effect of insulin on both total limb flow and microvascular recruitment (measured using either 1-MX or CEU) and blunted glucose uptake by 40% ( P < 0.05). We conclude that insulin specifically recruits flow to the microvasculture in skeletal muscle via a nitric oxide-dependent pathway and that this may be important to insulin's overall action to regulate glucose disposal.

Abstract 16949: Failing Fontan: Genesis of a Subpulmonary Neo-ventricle From Engineered Heart Tissue

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Daniel Biermann ◽  
Alexandra Eder ◽  
Hatim Seoudy ◽  
Florian Arndt ◽  
Tillmann Schuler ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Connexin 43 ◽  
Wistar Rats ◽  
Vena Cava ◽  
Heart Tissue ◽  
Long Term Outcome ◽  
Engineered Heart Tissue ◽  
The Right

Introduction: Fontan palliation is the treatment of choice for patients with morphological or functional univentricular hearts. The unphysiologic and non-pulsatile pulmonary blood flow results in multiorgan complications and a poor long-term outcome. We evaluated graft survival and histomorphology of a pulsatile Fontan conduit generated from Engineered Heart Tissue (EHT) after implantation in a rat model. Hypothesis: We hypothesized that EHT matures and remains contractile in the setting of venous (Fontan-like) preload. Methods: EHT was generated from ventricular cardiomyocytes of neonatal Wistar rats, fibrinogen, thrombin and DMEM. After culture for 14 days constructs were implanted around the right superior vena cava of Wistar rats (n=12, 300-350 g). Immunosupression was achieved by daily subcutaneous injection of Cyclosporin A (25 mg/kg BW) and Methylprednisolone (2 mg/kg BW). MRI (Bruker) was used to assess condensation of EHTs in vivo. Animals were euthanized after 7, 14, 28 and 56 days postoperatively for histomorphological analysis. Transmission electron microscopy was used to evaluate sarcomeric integrity of cardiomyocytes within the construct. Results: In culture, EHTs started beating around day 8 and remained contractile in vivo throughout the experiment (d7=3/3, d14=2/3, d28=3/3, d56=2/3). All animals survived circumferential implantation of EHTs around the right SVC via a right thoracotomy. MRI (d14, n=3) revealed no constriction or stenosis of the SVC by the constructs. Hematoxylin and Eosin staining showed densely packed bundles of cardiomyocytes within the EHT conduit and intense vascularisation. Immunolabeling of actinin and connexin 43 indicated adequate maturation of cardiomyocytes after grafting around the right SVC in rats. Conclusions: EHTs placed around the superior caval vein of Wistar rats survive and contract for a considerable time after implantation. Histomorphology revealed a matured phenotype of grafted cardiomyocytes and an adequate vascularisation. The functional benefit of a contractile neo-ventricle to propel pulmonary blood flow in Fontan patients remains to be evaluated.

scholarly journals Novel Polydimethylsiloxane (PDMS) Pulsatile Vascular Tissue Phantoms for the In-Vitro Investigation of Light Tissue Interaction in Photoplethysmography

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4246
Author(s):  
Michelle Nomoni ◽  
James M. May ◽  
Panayiotis A. Kyriacou
Keyword(s):  
Blood Flow ◽  
Vascular Tissue ◽  
Dip Coating ◽  
Tissue Properties ◽  
India Ink ◽  
Tissue Phantoms ◽  
In Vitro Investigation ◽  
Set Up

Currently there exists little knowledge or work in phantoms for the in-vitro evaluation of photoplethysmography (PPG), and its’ relationship with vascular mechanics. Such phantoms are needed to provide robust, basic scientific knowledge, which will underpin the current efforts in developing new PPG technologies for measuring or estimating blood pressure, blood flow and arterial stiffness, to name but a few. This work describes the design, fabrication and evaluation of finger tissue-simulating pulsatile phantoms with integrated custom vessels. A novel technique has been developed to produce custom polydimethylsiloxane (PDMS) vessels by a continuous dip-coating process. This process can accommodate the production of different sized vessel diameters (1400–2500 µm) and wall thicknesses (56–80 µm). These vessels were embedded into a mould with a solution of PDMS and India ink surrounding them. A pulsatile pump experimental rig was set up to test the phantoms, where flow rate (1–12 L·min−1), heart rate (40–120 bpm), and total resistance (0–100% resistance clamps) could be controlled on demand. The resulting flow profiles approximates human blood flow, and the detected contact PPG signal (red and infrared) from the phantom closely resembles the morphology of in-vivo PPG waveforms with signal-to-noise ratios of 38.16 and 40.59 dB, for the red and infrared wavelengths, respectively. The progress made by this phantom development will help in obtaining new knowledge in the behaviour of PPG’s under differing flow conditions, optical tissue properties and differing vessel stiffness.

Vascular recruitment in skeletal muscle during exercise and hyperinsulinemia assessed by contrast ultrasound

2002 ◽  
Vol 282 (3) ◽  
pp. E714-E720 ◽  
Author(s):  
Dana Dawson ◽  
Michelle A. Vincent ◽  
Eugene J. Barrett ◽  
Sanjiv Kaul ◽  
Andrew Clark ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Femoral Artery ◽  
Artery Blood Flow ◽  
Contrast Enhanced Ultrasound ◽  
Contrast Enhanced ◽  
Adductor Muscles ◽  
Femoral Artery Blood Flow ◽  
Contrast Ultrasound

The purpose of this study was to noninvasively quantify the effects of insulin on capillary blood volume (capBV) and RBC velocity ( V RBC) in skeletal muscle in vivo with the use of contrast-enhanced ultrasound. We performed contrast ultrasound of the rat hindlimb adductor muscles at baseline and after 2-h infusions of either insulin (3 or 40 mU · kg−1 · min−1) or saline. Saline-treated animals were also studied during contractile exercise. V RBC and capBV were calculated from the relation between pulsing interval and video intensity. Femoral artery blood flow, measured by a flow probe, increased with both contractile exercise and insulin. Contractile exercise increased capBV more than twofold and V RBC fivefold. Insulin also increased capBV more than twofold in a dose-dependent fashion but did not significantly alter V RBC. Saline infusion did not significantly alter capBV, V RBC, or femoral artery blood flow. We conclude that physiological changes in skeletal muscle capillary perfusion can be assessed in vivo with the use of contrast-enhanced ultrasound. Exercise increases both V RBC and capBV, whereas hyperinsulinemia selectively increases only capBV, which may enhance skeletal muscle glucose uptake.

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