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April 1, 1971Journal of Clinical InvestigationOpen Access

Practolol reversed coronary responses to norepinephrine and nerve stimulation from dilatation to constriction, indicating their vasodilator action is indirect via myocardial beta receptors, whereas isoproterenol has both direct and indirect vasodilator effects.

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Why the study?

What are the direct and indirect effects of adrenergic stimuli on coronary vessels in an intact beating dog heart model?

Population

Dogs (intact beating heart model, left circumflex coronary artery perfused with arterial blood)

Comparison

Adrenergic stimuli with and without practolol… vs Responses before practolol administration

Design

Preclinical

Authors

DMDonald R. McRavenAMAllyn L. MarkFAFrançois M. Abboud

Discussion

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Overview

Animal findings on indirect beta-mediated coronary effects warrant cautious interpretation; leaves open human translation and clinical relevance.

Structured PICO

What are the direct and indirect effects of adrenergic stimuli on coronary vessels in an intact beating dog heart model?

P
Population
Dogs (intact beating heart model, left circumflex coronary artery perfused with arterial blood)
I
Intervention
Adrenergic stimuli (intracoronary isoproterenol, norepinephrine, and electrical stimulation of left cardiac sympathetic nerves) with and without practolol, propranolol, and phentolamine
C
Comparator
Responses before practolol administration
O
Outcome
Coronary perfusion pressure (vasodilatation/constriction)surrogate

The study demonstrates that coronary vasodilation from norepinephrine and sympathetic nerve stimulation is primarily indirect via myocardial beta receptors, while direct effects are minimal and alpha-receptor mediated.

Cite This Study

McRaven et al. (1971) studied this question.

synapsesocial.com/papers/6a1e9a50edce398519af1274https://doi.org/10.1172/jci106548
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Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

  1. 1Differences in Direct Effects of Adrenergic Stimuli on Coronary, Cutaneous, and Muscular Vessels1972 · 102 citations
  2. 2Opposed responses of large and small coronary arteries to propranolol during exercise in dogs1991 · 28 citations
  3. 3Regulation of large coronary arteries by beta-adrenergic mechanisms in the conscious dog.1982 · 77 citations
  4. 4Coronary Vasodilatation and Adrenergic Receptors in the Dog Heart and Coronary1975 · 19 citations
  5. 5The effects of pronethalol and propranolol on the coronary circulation of the dog1969 · 13 citations