TY - JOUR
T1 - Role of β2 adrenergic receptors in human atherosclerotic coronary arteries
AU - Barbato, Emanuele
AU - Piscione, Federico
AU - Bartunek, Jozef
AU - Galasso, Gennaro
AU - Cirillo, Plinio
AU - De Luca, Giuseppe
AU - Iaccarino, Guido
AU - De Bruyne, Bernard
AU - Chiariello, Massimo
AU - Wijns, William
PY - 2005/1/25
Y1 - 2005/1/25
N2 - Background - Adrenergic regulation of coronary vasomotion is balanced between α1-adrenergic-mediated (α1-AR) constriction and β2-adrenergic-mediated (β2-AR) relaxation. This study aimed at assessing the role of β2-ARs in normal, mildly atherosclerotic, and stenotic human coronary arteries. Methods and Results - During intracoronary (IC) infusion of increasing doses of the β2-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 NG-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, P2-adrenergic vasodilatation is impaired, and this might contribute to alter the vasomotor balance, further precipitating myocardial ischemia during sympathetic activation.
AB - Background - Adrenergic regulation of coronary vasomotion is balanced between α1-adrenergic-mediated (α1-AR) constriction and β2-adrenergic-mediated (β2-AR) relaxation. This study aimed at assessing the role of β2-ARs in normal, mildly atherosclerotic, and stenotic human coronary arteries. Methods and Results - During intracoronary (IC) infusion of increasing doses of the β2-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 NG-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, P2-adrenergic vasodilatation is impaired, and this might contribute to alter the vasomotor balance, further precipitating myocardial ischemia during sympathetic activation.
KW - Acetylcholine
KW - Atherosclerosis
KW - Endothelium
KW - Receptors, adrenergic, alpha
KW - Receptors, adrenergic, beta
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U2 - 10.1161/01.CIR.0000153270.25541.72
DO - 10.1161/01.CIR.0000153270.25541.72
M3 - Article
C2 - 15642763
AN - SCOPUS:19944431741
VL - 111
SP - 288
EP - 294
JO - Circulation
JF - Circulation
SN - 0009-7322
IS - 3
ER -