Document Detail

Blunted hypoxic pulmonary vasoconstriction by increased lung vascular pressures.
MedLine Citation:
PMID:  1126894     Owner:  NLM     Status:  MEDLINE    
We tested the hypothesis that increased pressures within the lung vessels would inhibit hypoxic pulmonary vasoconstriction at all levels of alveolar CO2 tension. Selective hypoxia of the left lower lobe of the lung in open chested dogs caused the electromagnetically measured blood flow to the lobe to decrease 51 plus or minus 4 (SE) percent and its vascular resistance to increase 132 plus or minus 13 percent. Pressure and blood flow in the main pulmonary artery and left atrial pressure did not change during the hypoxic response. Stepwise increments in left artrial and pulmonary arterial pressures induced either by inflating a left atrial balloon or infusing dextran, progressively diminished the vasoconstrictive response to hypoxia. The response was usually abolished when left atrial pressure reached 25 mmHg. For all vascular pressures, hypoxic vasoconstriction was blunted by hypocapnic alkalosis but not enhanced by hypercapnia. We conclude that the redistribution of blood flow away from an hypoxic lobe of the lung to lobes with high Po2 was greatly attenuated by increasing pressures within lung vessels or by inducing respiratory alkalosis.
J L Benumof; E A Wahrenbrock
Related Documents :
2366754 - The metabolic effect of carbon monoxide on the heart.
10589024 - Quantitative electron microscopic study of the hypoxic fetal sheep heart.
24775384 - Association between adiposity and blood pressure levels between the ages of 6 and 16 ye...
10477504 - Effects of an antihypertensive medication on functional capacity under simulated flight...
2440284 - Anaphylactoid reactions and histamine release do not occur after application of the opi...
10464004 - 24-hour ambulatory blood pressure monitoring: a comparison between transdermal glyceryl...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology     Volume:  38     ISSN:  0021-8987     ISO Abbreviation:  J Appl Physiol     Publication Date:  1975 May 
Date Detail:
Created Date:  1975-08-07     Completed Date:  1975-08-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0376576     Medline TA:  J Appl Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  846-50     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Alkalosis, Respiratory / physiopathology
Atrial Function
Blood Pressure*
Blood Volume
Dextrans / pharmacology
Hypercapnia / physiopathology
Pulmonary Artery / physiology
Pulmonary Circulation*
Regional Blood Flow
Vascular Resistance*
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Altered control of skin blood flow at high skin and core temperatures.
Next Document:  Measurement of pleural effusion by electrical impedance.