Role of β 2 Adrenergic Receptors in Human Atherosclerotic Coronary Arteries
- 25 January 2005
- journal article
- research article
- Published by Ovid Technologies (Wolters Kluwer Health) in Circulation
- Vol. 111 (3), 288-294
- https://doi.org/10.1161/01.cir.0000153270.25541.72
Abstract
Background— Adrenergic regulation of coronary vasomotion is balanced between α 1 -adrenergic–mediated (α 1 -AR) constriction and β 2 -adrenergic–mediated (β 2 -AR) relaxation. This study aimed at assessing the role of β 2 -ARs in normal, mildly atherosclerotic, and stenotic human coronary arteries. Methods and Results— During intracoronary (IC) infusion of increasing doses of the β 2 -AR agonist salbutamol (0.15, 0.3, and 0.6 μg/min) and the endothelial vasodilator acetylcholine (1, 3, and 10 μg/min), we measured (1) changes in lumen diameter (LD) by quantitative coronary angiography in 34 normal, 55 mildly atherosclerotic, and 42 stenotic coronary artery segments and (2) changes in average peak velocity (APV) and coronary blood flow (CBF) with the use of Doppler flow wire in 11 normal, 10 mildly atherosclerotic, and 11 stenotic coronary arteries. In 6 of 11 stenotic coronary arteries, the protocol was repeated after an IC bolus (12 μg/kg) of the α-adrenergic blocker phentolamine. In 6 of 11 normal coronary arteries, the protocol was repeated after an IC infusion (60 μmol/min) of N G -monomethyl- l -arginine (L-NMMA), a nitric oxide inhibitor. Neither salbutamol IC infusion nor acetylcholine significantly changed heart rate or blood pressure, whereas L-NMMA slightly increased blood pressure. In normal coronary arteries, salbutamol increased LD (LD max %: 11±2, P P P P P P P P P P P P P P P P =NS) and CBF (CBF max %: −10±13, P =NS). In stenotic coronary arteries, acetylcholine significantly reduced LD (LD max %: −15±3, P P P Conclusions— In severely atherosclerotic coronary arteries, β 2 -adrenergic vasodilatation is impaired, and this might contribute to alter the vasomotor balance, further precipitating myocardial ischemia during sympathetic activation.Keywords
This publication has 13 references indexed in Scilit:
- Validation of coronary flow reserve measurements by thermodilution in clinical practiceEuropean Heart Journal, 2004
- Effects of intravenous dobutamineon coronary vasomotion in humansJournal of the American College of Cardiology, 2003
- Norepinephrine Elicits β 2 -Receptor–Mediated Dilation of Isolated Human Coronary ArteriolesCirculation, 2002
- β-Adrenoceptor Subtypes in Human Coronary ArteryJournal of Cardiovascular Pharmacology, 1995
- Unsuspected coronary artery disease revealed by administration of nebulised salbutamol.Heart, 1994
- Endothelium-mediated coronary blood flow modulation in humans. Effects of age, atherosclerosis, hypercholesterolemia, and hypertension.JCI Insight, 1993
- The Effect of Atherosclerosis on the Vasomotor Response of Coronary Arteries to Mental StressNew England Journal of Medicine, 1991
- Responses of the rabbit epicardial coronary artery to acetylcholine and adrenoceptor agonistsCardiovascular Research, 1991
- Regional coronary vasoconstriction after combined beta-adrenergic and calcium channel blockade in patients with coronary artery diseaseJournal of the American College of Cardiology, 1985
- Attenuation of coronary vascular resistance by selective alpha1,-adrenergic blockade in patients with coronary artery diseaseJournal of the American College of Cardiology, 1985