Document Detail

Pressure-flow-volume relationships in pulmonary circulation of normal highlanders.
MedLine Citation:
PMID:  985384     Owner:  NLM     Status:  MEDLINE    
Pulmonary vascular pressures and blood flow were measured with and without unilateral pulmonary arterial occlusion (UPAO) at rest and during exercise in 10 normal highlanders at La Paz, Bolivia (altitude, 3,750 m). In 6 other highlanders at rest and during exercise, pulmonary pressures, flow, and blood volume were measured during air breathing (PIO2 congruent to 100 Torr) and 29-30% oxygen (PIO2 congruent to 150 Torr). During air breathing, pulmonary vascular resistance was elevated at rest and did not change with exercise. Pulmonary arterial pressure rose less at rest with UPAO than during exercise without UPAO, and pulmonary vascular resistance was less in the former. Raising PaO2 to normal sea-level values had no effects on the pulmonary circulation at rest but prevented to a large extent the rise in pulmonary arterial pressure during exercise. Hence pulmonary vascular resistance during exercise was lower with oxygen than without. Thus, hypoxic vasoconstriction contributed to the pulmonary hypertension during exercise in normal highlanders. Circumstantial evidence suggests that this is related to the profound mixed venous hypoxemia caused by exercise in a hypoxic environment.
A Lockhart; M Zelter; J Mensch-Dechene; G Antezana; M Paz-Zamora; E Vargas; J Coudert
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of applied physiology     Volume:  41     ISSN:  0021-8987     ISO Abbreviation:  J Appl Physiol     Publication Date:  1976 Oct 
Date Detail:
Created Date:  1976-12-23     Completed Date:  1976-12-23     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0376576     Medline TA:  J Appl Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  449-56     Citation Subset:  IM; S    
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MeSH Terms
Blood Pressure
Cardiac Output
Oxygen / blood
Physical Exertion*
Pulmonary Circulation*
Regional Blood Flow
Vascular Resistance
Reg. No./Substance:

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