| Pressure and flow changes in the pulmonary circulation in exercising sheep: evidence for elevated microvascular pressure. | |
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MedLine Citation:
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PMID: 8466128 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The purpose of this study was to measure hemodynamic and transvascular filtration changes in the lung during strenuous exercise in sheep. The specific goals were (1) to determine the nature of the reduction in pulmonary arterial pressure (Ppa) after its initial peak rise with onset of exercise; (2) to use a pulmonary artery catheter distal wedge technique ("microwedge") to better assess longitudinal changes in resistance in the pulmonary circulation with exercise; and (3) to compare lung lymph flow and protein concentration changes at comparable estimated microvascular pressure (Pmv) (mean Ppa - mean left atrial pressure) (Pla) x 0.4 + mean Pla) during exercise versus passive left atrial hypertension to determine whether exercise causes a higher than expected lymph flow. We found that cardiac output rises quickly and thereafter remains constant with constant-rate exercise, and, thus, the secondary reduction in Ppa was due to vasodilation and/or recruitment. The microwedge pressure rose more than did Pla, suggesting that actual Pmv was probably higher than that estimated. With hypoxia, most of the change in pulmonary vascular resistance was in upstream vessels (arteries and capillaries), as was most of the exercise-induced vasodilation. Lymph flow rose more quickly and was much higher during brief exercise than during left atrial hypertension at a comparable calculated Pmv, and lymph protein content decreased more quickly. The data point to a Pmv with strenuous exercise that is higher than expected. |
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Authors:
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J H Newman; C P Cochran; R J Roselli; R E Parker; L S King |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The American review of respiratory disease Volume: 147 ISSN: 0003-0805 ISO Abbreviation: Am. Rev. Respir. Dis. Publication Date: 1993 Apr |
Date Detail:
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Created Date: 1993-04-30 Completed Date: 1993-04-30 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 0370523 Medline TA: Am Rev Respir Dis Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 921-6 Citation Subset: AIM; IM; S |
Affiliation:
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Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Anoxia / physiopathology Atrial Function Blood Pressure* Cardiac Output Lung Lymph / physiology Microcirculation / physiology Physical Exertion* Pulmonary Artery / physiology Pulmonary Circulation / physiology* Pulmonary Wedge Pressure Sheep Vascular Resistance |
| Grant Support | |
ID/Acronym/Agency:
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HL-07123/HL/NHLBI NIH HHS; HL-19153/HL/NHLBI NIH HHS; HL-45107/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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