Effects of graded exercise on bronchial blood flow and airway dimensions in sheep

2007 ◽  
Vol 20 (2) ◽  
pp. 178-189 ◽  
Author(s):  
R. Bishop ◽  
D. McLeod ◽  
S. McIlveen ◽  
R. Blake ◽  
R. Gunther ◽  
...  
Keyword(s):  
Blood Flow ◽  
Graded Exercise ◽  
Airway Dimensions

Costal vs. crural diaphragmatic blood flow during submaximal and near-maximal exercise in ponies

1988 ◽  
Vol 65 (4) ◽  
pp. 1514-1519 ◽  
Author(s):  
M. Manohar
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Left Atrium ◽  
Maximal Exercise ◽  
Muscle Blood Flow ◽  
Intercostal Muscle ◽  
Quiet Breathing ◽  
Blood Flows ◽  
Graded Exercise ◽  
Crural Diaphragm

The present study was carried out 1) to compare blood flow in the costal and crural regions of the equine diaphragm during quiet breathing at rest and during graded exercise and 2) to determine the fraction of cardiac output needed to perfuse the diaphragm during near-maximal exercise. By the use of radionuclide-labeled 15-micron-diam microspheres injected into the left atrium, diaphragmatic and intercostal muscle blood flow was studied in 10 healthy ponies at rest and during three levels of exercise (moderate: 12 mph, heavy: 15 mph, and near-maximal: 19-20 mph) performed on a treadmill. At rest, in eucapnic ponies, costal (13 +/- 3 ml.min-1.100 g-1) and crural (13 +/- 2 ml.min-1.100 g-1) phrenic blood flows were similar, but the costal diaphragm received a much larger percentage of cardiac output (0.51 +/- 0.12% vs. 0.15 +/- 0.03% for crural diaphragm). Intercostal muscle perfusion at rest was significantly less than in either phrenic region. Graded exercise resulted in significant progressive increments in perfusion to these tissues. Although during exercise, crural diaphragmatic blood flow was not different from intercostal muscle blood flow, these values remained significantly less (P less than 0.01) than in the costal diaphragm. At moderate, heavy, and near-maximal exercise, costal diaphragmatic blood flow (123 +/- 12, 190 +/- 12, and 245 +/- 18 ml.min-1.100 g-1) was 143%, 162%, and 162%, respectively, of that for the crural diaphragm (86 +/- 10, 117 +/- 8, and 151 +/- 14 ml.min-1.100 g-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of the Circulation During Exercise

1956 ◽  
Vol 184 (3) ◽  
pp. 613-623 ◽  
Author(s):  
A. C. Barger ◽  
V. Richards ◽  
J. Metcalfe ◽  
B. Günther
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Oxygen Consumption ◽  
Steady State ◽  
Rest Period ◽  
Moderate Exercise ◽  
Work Intensity ◽  
Short Bout ◽  
Graded Exercise ◽  
Oxygen Difference

Oxygen consumption and cardiac output (direct Fick) have been measured in normal dogs at rest and during graded exercise on the treadmill up to a work intensity of 5 mph and 10°. Systemic and pulmonary artery pressures have also been recorded. The changes in cardiac output produced ‘at rest’ by excitement were frequently as large as those induced by moderate exercise. A short bout of exercise followed by a rest period was far more efficacious in producing lower and more uniform results during rest and subsequent exercise than a prolonged rest period alone. Under such conditions the ‘steady state’ was reached in 3 minutes or less of exercise. The linear relation between oxygen consumption and cardiac output during exercise in the dog is similar to that observed in man, and in the horse. The possible significance of this similarity is discussed and it is suggested that the data are consistent with the hypothesis that the increase in blood flow during exercise is largely the increase in muscle flow with a constant arteriovenous oxygen difference of approximately 14 vol. %.

scholarly journals The effect of sitting and graded exercise on the distribution of pulmonary blood flow.

Thorax ◽  
1969 ◽  
Vol 24 (4) ◽  
pp. 506-506
Author(s):  
B Bake ◽  
J Bjure ◽  
J Widimsky
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Graded Exercise

John Ludbrook APPS Symposium Coronary-Bronchial Blood Flow And Airway Dimensions In Exercise-Induced Syndromes

2001 ◽  
Vol 28 (5-6) ◽  
pp. 472-478 ◽  
Author(s):  
Sw White ◽  
Kf Pitsillides ◽  
Gh Parsons ◽  
Sg Hayes ◽  
Ra Gunther ◽  
...  
Keyword(s):  
Blood Flow ◽  
Exercise Induced ◽  
Airway Dimensions

scholarly journals Similarity of Blood Flow in the Normal and the Sympathectomized Dog Hind Limb during Graded Exercise

1970 ◽  
Vol 26 (2) ◽  
pp. 185-199 ◽  
Author(s):  
DAVID E. DONALD ◽  
DEREK J. ROWLANDS ◽  
DAVID A. FERGUSON
Keyword(s):  
Blood Flow ◽  
Hind Limb ◽  
Graded Exercise

Blood flow velocity in the common carotid artery in humans during graded exercise on a treadmill

1995 ◽  
Vol 70 (3) ◽  
pp. 234-239 ◽  
Author(s):  
Zheng-Lin Jiang ◽  
Hisao Yamaguchi ◽  
Akira Takahashi ◽  
Shingo Tanabe ◽  
Noboru Utsuyama ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Artery ◽  
Flow Velocity ◽  
Common Carotid Artery ◽  
Blood Flow Velocity ◽  
Graded Exercise ◽  
The Common

Plasma lactate concentration and muscle blood flow during dynamic exercise with negative-pressure breathing

2000 ◽  
Vol 89 (6) ◽  
pp. 2196-2205 ◽  
Author(s):  
Y. Kamijo ◽  
Y. Takeno ◽  
A. Sakai ◽  
M. Inaki ◽  
T. Okumoto ◽  
...  
Keyword(s):  
Blood Flow ◽  
Negative Pressure ◽  
Muscle Blood Flow ◽  
Lactate Concentration ◽  
Dynamic Exercise ◽  
Plasma Lactate ◽  
Vascular Conductance ◽  
Graded Exercise ◽  
Plasma Lactate Concentration ◽  
Negative Pressure Breathing

This study assessed the hypothesis that increasing cardiac filling pressure (CFP) would enhance contracting muscle blood flow (MBF) by stretching cardiopulmonary baroreceptors and attenuate the increase in plasma lactate concentration ([Lac−]p) during dynamic exercise. Continuous negative-pressure breathing (CNPB) (−15 cmH2O) was used to increase the CFP by accelerating the venous return to the heart. In the first series of experiments, 10 men performed a graded exercise seated on a cycle ergometer with (N1) and without CNPB (C1). The increase in [Lac−]p for N1 was attenuated at 60%, 90%, and 100% of maximal exercise intensity compared with that in C1 ( P < 0.001). Also, the increases in mean arterial pressure (MAP) and plasma catecholamine concentrations were attenuated in N1 compared with those in C1 throughout the graded exercise ( P < 0.05). However, heart rate and pulse pressure were not significantly influenced by CNPB. Second, we studied the impact of CNPB on forearm MBF during a rhythmic handgrip exercise in 5 of the 10 subjects. Forearm MBF was measured immediately after cessation of the exercise by venous occlusion plethysmography at rest, 30%, 50%, and 70% of maximal work load (WLmax) with (N2) and without CNPB (C2). Forearm MBF and vascular conductance for both trials increased with the increase in intensity, but forearm skin blood flow measured by laser-Doppler flowmetry remained unchanged. MBF and vascular conductance in N2, however, increased more than in C2 at every intensity ( P < 0.01) except for MBF at 70% WLmax, whereas the increase in MAP for N2 was attenuated compared with that in C2 ( P < 0.05). Thus augmented active muscle vasodilation occurred in N2 with a lower increase in MAP compared with that in C2. These findings suggest that the stretch of intrathoracic baroreceptors, such as cardiopulmonary mechanoreceptors, by CNPB increased MBF by suppressing sympathetic nerve activity. The attenuation of the increase in [Lac−]p might be caused, at least partially, by the increased MBF.

John Ludbrook APPS Symposium Coronary-Bronchial Blood Flow And Airway Dimensions In Exercise-Induced Syndromes

2001 ◽  
Vol 28 (5-6) ◽  
pp. 472-478
Author(s):  
Sw White ◽  
Kf Pitsillides ◽  
Gh Parsons ◽  
Sg Hayes ◽  
Ra Gunther ◽  
...  
Keyword(s):  
Blood Flow ◽  
Exercise Induced ◽  
Airway Dimensions

Blood flow to respiratory, cardiac, and limb muscles in dogs during graded exercise

1976 ◽  
Vol 231 (5) ◽  
pp. 1515-1519 ◽  
Author(s):  
DE Fixler ◽  
JM Atkins ◽  
JH Mitchell ◽  
LD Horwitz
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Gastrocnemius Muscle ◽  
Submaximal Exercise ◽  
Moderate Exercise ◽  
Radioactive Microspheres ◽  
Graded Exercise ◽  
Limb Muscles ◽  
The Brain ◽  
Distribution Of Cardiac Output

The distribution of cardiac output was analyzed in six dogs, with the animals at rest and running on a level treadmill for 3 min at 3-4 mph (mild exercise) and 3 min at 6-8 mph (moderate exercise). Organ flows were measured using 25-mug-diam radioactive microspheres. Cardiac output averaged 2.5, 4.6, and 5.7 liters/min, for rest, mild exercise, and moderate exercise, respectively. The greatest change was in diaphragmatic flow which increased by 275% with mild exercise and 500% with moderate exercise. Flow to intercostal muscles increased by 160 and 186%, to the exercising gastrocnemius muscle by 153 and 224%, and to cardiac muscle by 57 and 109% during mild and moderate exercise, respectively. Renal and cerebral flows did not change significantly. Significant decreases in flow occurred in the small and large intestines during moderate exercise. It is concluded that the increase in cardiac output during submaximal exercise was redistributed in a manner which limited flow to the brain, intestines, and kidneys and increased flow flow to the diaphragm, heart, and limb muscles.

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