Document Detail

Little carbon dioxide diffusional shunting in coronary circulation.
MedLine Citation:
PMID:  3115119     Owner:  NLM     Status:  MEDLINE    
The magnitude of CO2 countercurrent diffusional trapping (net diffusion from coronary venous to coronary arterial vessels) in the myocardium was determined. The left main coronary artery was pump perfused with a modified Gregg cannula in open-chest, heart-blocked, anesthetized dogs. Coronary venous PCO2, pH, and PO2 were simultaneously measured with a rapidly responding continuous electrode-cuvette system. Coronary venous CO2 concentration was calculated from the electrode outputs and a corresponding hemoglobin determination. After a step change in coronary flow, the amount of CO2 washed out or retained by the perfused myocardium was determined from the resulting coronary venous CO2 concentration changes. Analysis of the data with a compartmental mass balance model indicated that CO2 washouts and retentions were best fit with a model in which 80% of the myocardial CO2 resides in the interstitial and intracellular compartments and the remaining 20% in vascular compartments. The maximal diffusional trapping compatible with the data resulted in a modest end-capillary-to-end-venous CO2 concentration ratio of 1.02 to 1.04 at resting coronary flows. It is concluded that diffusional trapping of myocardial CO2 was below the detection limits of the experiment and that at normal coronary blood flow rates there is little CO2 diffusional trapping.
S A Katz; E O Feigl
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  253     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1987 Sep 
Date Detail:
Created Date:  1987-10-22     Completed Date:  1987-10-22     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H614-25     Citation Subset:  IM    
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MeSH Terms
Carbon Dioxide / metabolism*
Coronary Circulation*
Coronary Vessels / physiology*
Hydrogen-Ion Concentration
Models, Theoretical
Myocardium / metabolism
Oxygen / metabolism
Regional Blood Flow
Time Factors
Grant Support
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

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

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