Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs

Johnathan Tune, Keith Neu Richmond, Mark W. Gorman, Eric O. Feigl

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

Background - Inhibition of nitric oxide (NO) synthesis results in very little change in coronary blood flow, but this is thought to be because cardiac adenosine concentration increases to compensate for the loss of NO vasodilation. Accordingly, in the present study, adenosine measurements were made before and during NO synthesis inhibition during exercise. Methods and Results- Experiments were performed in chronically instrumented dogs at rest and during graded treadmill exercise before and during inhibition of NO synthesis with N(ω)-nitro-L-arginine (L-NNA, 35 mg/kg IV). Before inhibition of NO synthesis, myocardial oxygen consumption increased ≃3.7-fold, and coronary blood flow increased ≃3.2-fold from rest to the highest level of exercise, and this was not changed by NO synthesis inhibition. Coronary venous oxygen tension was modestly reduced by L-NNA at all levels of myocardial oxygen consumption. However, the slope of the relationship between myocardial-oxygen consumption and coronary venous oxygen tension was not altered by L-NNA. Inhibition of NO synthesis did not increase coronary venous plasma or estimated interstitial adenosine concentration. During exercise, estimated interstitial adenosine remained well below the threshold concentration necessary for coronary vasodilation before or after L-NNA. Conclusions - NO causes a modest coronary vasodilation at rest and during exercise but does not act as a local metabolic vasodilator. Adenosine does not mediate a compensatory local metabolic coronary vasodilation when NO synthesis is inhibited.

Original languageEnglish (US)
Pages (from-to)2942-2948
Number of pages7
JournalCirculation
Volume101
Issue number25
StatePublished - Jun 27 2000
Externally publishedYes

Fingerprint

Adenosine
Nitric Oxide
Dogs
Vasodilation
Oxygen Consumption
Oxygen
Vasodilator Agents
Arginine

Keywords

  • Adenosine
  • Coronary disease
  • Exercise
  • Nitric oxide

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

Tune, J., Richmond, K. N., Gorman, M. W., & Feigl, E. O. (2000). Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs. Circulation, 101(25), 2942-2948.

Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs. / Tune, Johnathan; Richmond, Keith Neu; Gorman, Mark W.; Feigl, Eric O.

In: Circulation, Vol. 101, No. 25, 27.06.2000, p. 2942-2948.

Research output: Contribution to journalArticle

Tune, J, Richmond, KN, Gorman, MW & Feigl, EO 2000, 'Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs', Circulation, vol. 101, no. 25, pp. 2942-2948.
Tune J, Richmond KN, Gorman MW, Feigl EO. Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs. Circulation. 2000 Jun 27;101(25):2942-2948.
Tune, Johnathan ; Richmond, Keith Neu ; Gorman, Mark W. ; Feigl, Eric O. / Role of nitric oxide and adenosine in control of coronary blood flow in exercising dogs. In: Circulation. 2000 ; Vol. 101, No. 25. pp. 2942-2948.
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