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Inhibitory role of the coronary arterial endothelium to alpha-adrenergic stimulation in experimental heart failure.

Publication ,  Journal Article
Main, JS; Forster, C; Armstrong, PW
Published in: Circ Res
April 1991

The role of the endothelium in regulating coronary alpha-adrenergic tone was evaluated in isolated coronary arterial rings from dogs with and without pacing-induced congestive heart failure (CHF). The maximal contractile response to methoxamine was attenuated approximately 43% (p less than 0.05) in both intact and denuded CHF rings compared with control. Conversely, norepinephrine-induced contractions were diminished 58% in intact CHF vessels and 39% in denuded CHF vessels (p less than 0.05). Denudation did not alter responses to methoxamine but significantly (p less than 0.05) augmented the tension generated by norepinephrine in both control (1.7-fold) and CHF (2.4-fold) arteries. In both intact control and CHF coronary arteries, norepinephrine elicited rapid, transient relaxations that preceded slow, sustained contractions; the initial relaxation phase was endothelium dependent, because denudation eliminated the response. Relaxations to the selective alpha 2-adrenoceptor agonist BHT 920 were also dependent on the presence of an endothelium. At peak CHF, endothelium-dependent relaxations to norepinephrine and BHT 920 were enhanced, whereas relaxations to nitroglycerin and acetylcholine were unaltered. The data suggest that alpha-adrenergic tone in canine coronary arteries is diminished by pacing-induced CHF because of a decrease in alpha 1-adrenoceptor-mediated constriction and an enhanced capacity of the endothelium to antagonize the direct vascular smooth muscle response of norepinephrine through endothelium-dependent, alpha 2-adrenoceptor-mediated relaxations.

Duke Scholars

Published In

Circ Res

DOI

ISSN

0009-7330

Publication Date

April 1991

Volume

68

Issue

4

Start / End Page

940 / 946

Location

United States

Related Subject Headings

  • Receptors, Adrenergic, alpha
  • Potassium Chloride
  • Norepinephrine
  • Muscle, Smooth, Vascular
  • Muscle Relaxation
  • Methoxamine
  • Male
  • In Vitro Techniques
  • Homeostasis
  • Heart Failure
 

Citation

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Main, J. S., Forster, C., & Armstrong, P. W. (1991). Inhibitory role of the coronary arterial endothelium to alpha-adrenergic stimulation in experimental heart failure. Circ Res, 68(4), 940–946. https://doi.org/10.1161/01.res.68.4.940
Main, J. S., C. Forster, and P. W. Armstrong. “Inhibitory role of the coronary arterial endothelium to alpha-adrenergic stimulation in experimental heart failure.Circ Res 68, no. 4 (April 1991): 940–46. https://doi.org/10.1161/01.res.68.4.940.
Main, J. S., et al. “Inhibitory role of the coronary arterial endothelium to alpha-adrenergic stimulation in experimental heart failure.Circ Res, vol. 68, no. 4, Apr. 1991, pp. 940–46. Pubmed, doi:10.1161/01.res.68.4.940.

Published In

Circ Res

DOI

ISSN

0009-7330

Publication Date

April 1991

Volume

68

Issue

4

Start / End Page

940 / 946

Location

United States

Related Subject Headings

  • Receptors, Adrenergic, alpha
  • Potassium Chloride
  • Norepinephrine
  • Muscle, Smooth, Vascular
  • Muscle Relaxation
  • Methoxamine
  • Male
  • In Vitro Techniques
  • Homeostasis
  • Heart Failure