NSU-MD Faculty Articles

Consistent parallel relationships among myocardial oxygen consumption, coronary blood flow, and pericardial infusate adenosine concentration with various interventions and beta-blockade in the dog.

Publication Title

Circulation research

Publisher

Lippincott Williams & Wilkins

ISSN

0009-7330

Publication Date

7-1-1983

Keywords

Adenosine, Adrenergic beta-Antagonists, Animals, Calcium Chloride, Coronary Circulation, Dogs, Extracellular Space, Female, Male, Myocardium, Oxygen Consumption, Pericardial Effusion, Propranolol

Abstract

Coronary blood flow responds uniquely to changes in myocardial demand, regardless of the stimulus. If adenosine mediates this response, interstitial fluid adenosine concentration should also change in parallel with myocardial oxygen consumption and coronary blood flow during alterations of cardiac work. We tested this hypothesis by measuring coronary blood flow, myocardial oxygen consumption, and the concentration of adenosine in pericardial infusates, an index of interstitial fluid adenosine concentration, during six experimental conditions and control states in anesthetized, open-chest dogs. Significant alterations of myocardial oxygen consumption and coronary blood flow during aortic constriction, vagal stimulation, atrial pacing, or intravenous infusion of calcium chloride, norepinephrine, or isoproterenol were accompanied by significant alterations in pericardial infusate adenosine concentration. Significant linear relationships were determined among myocardial oxygen consumption, coronary blood flow, and pericardial infusate adenosine concentration for each of the experimental stimuli and their paired control values. There were no significant differences among the six different conditions for any of these relationships. In addition, these relationships were not altered by beta-blockade in five dogs subjected to aortic constriction and calcium infusion. Although beta-blockade may alter the effects of a stimulus, myocardial oxygen consumption, coronary blood flow, and adenosine all are affected proportionately. The results suggest that adenosine production responds to alterations of myocardial oxygen consumption independently of the stimulus which produces the change in oxygen demand, and the resultant change in interstitial fluid adenosine concentration may initiate the change in coronary blood flow to maintain the balance between oxygen supply and demand.

DOI

10.1161/01.RES.53.1.33

Volume

53

Issue

1

First Page

33

Last Page

41

Disciplines

Medicine and Health Sciences

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