Direct in vivo effects of nitric oxide on the coronary circulation

Jeffrey W. Chambers, Gregory S. Voss, Jason R. Snider, Susan M. Meyer, Julie L. Cartland, Robert F. Wilson

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

To determine the direct in vivo effects of nitric oxide (NO) on the coronary circulation, we infused NO-saturated saline (1.0 ± 0.1 mmol/l) into the coronary arteries of anesthetized dogs and measured changes in coronary blood flow velocity (CBFV) with a Doppler catheter, changes in coronary artery size with quantitative angiography, and transmural myocardial perfusion with radioactive microspheres. Boluses of NO (1-8 μmol) caused a stepwise increase in CBFV (3.1 ± 0.3 × basal CBFV at 8 μmol) similar to that caused by adenosine (2.6 ± 0.3 × basal CBFV, maximal dose). Continuous subselective infusions (0.1, 1.0, and 4.0 μmol/min) caused dose-dependent increases in CBFV (2.2 ± 0.3 × basal CBFV at 4.0 μmol/min) and in epicardial artery diameter (+15 ± 6% diam). Left main infusions (8 μmol/min) caused a stepwise increase in CBFV and in the endocardial-to-epicardial flow ratio without affecting systemic hemodynamics. Brief infusion of NO (2 min) did not significantly reduce acetylcholine-mediated endothelial NO release. Therefore, despite rapid metabolism, direct intraarterial infusion of NO can be given at a rate sufficient to overwhelm metabolic elimination, providing direct evidence that NO is a potent in vivo coronary vasodilator. Moreover, the enhanced subendocardial vasodilator response to direct NO infusion suggests increased regional sensitivity to NO.

Original languageEnglish (US)
Pages (from-to)H1584-H1593
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume271
Issue number4
DOIs
StatePublished - Oct 1996

Keywords

  • Artery size
  • Coronary blood flow velocity
  • Endothelium-mediated vasodilation
  • Transmural myocardial perfusion

Fingerprint Dive into the research topics of 'Direct in vivo effects of nitric oxide on the coronary circulation'. Together they form a unique fingerprint.

Cite this