Alpha-adrenoceptor blockade prevents exercise-induced vasoconstriction of stenotic coronary arteries

作     者：Julius, BK Vassalli, G Mandinov, L Hess, OM 

作者机构：Inselspital Bern Swiss Heart Ctr CH-3010 Bern Switzerland Univ Zurich Hosp Dept Internal Med Zurich Switzerland 

出 版 物：《JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY》 (美国心脏病学会志)

年 卷 期：1999年第33卷第6期

页      面：1499-1505页

核心收录：

学科分类：1002[医学-临床医学] 100201[医学-内科学(含：心血管病、血液病、呼吸系病、消化系病、内分泌与代谢病、肾病、风湿病、传染病)] 10[医学] 

主　　题：肾上腺素能α拮抗剂/投药和剂量 肾上腺素能α拮抗剂/副作用 肾上腺素能β受体拮抗剂/投药和剂量 肾上腺素能β受体拮抗剂/副作用 阿替洛尔/投药和剂量 阿替洛尔/副作用 冠状血管造影术/药物作用 冠状动脉循环/药物作用 冠状动脉循环/生理学 冠心病/药物疗法 冠心病/病理生理学 运动试验/药物作用 血流动力学/药物作用 美托洛尔/投药和剂量 美托洛尔/副作用 硝酸甘油/投药和剂量 硝酸甘油/副作用 酚妥拉明/投药和剂量 酚妥拉明/副作用 术前用药法 血管收缩/药物作用 血管收缩/生理学 血管舒张药/投药和剂量 血管舒张药/副作用 成年人 老年人 女(雌)性 人类 男(雄)性 中年人 

摘      要：OBJECTIVES The study aimed to evaluate the role of alpha-adrenergic mechanisms during dynamic exercise in both normal and stenotic coronary arteries. BACKGROUND Paradoxical vasoconstriction of stenotic coronary arteries has been reported during dynamic exercise and may be due to several factors such as alpha-adrenergic drive, a decreased release of nitric oxide, platelet aggregation with release of serotonin, or a passive collapse of the vessel wall. METHODS Twenty-six patients were studied at rest, during two levels of supine bicycle exercise and after 1.6 mg sublingual nitroglycerin The alpha-blocker phentolamine was given to 16 patients before exercise, five of whom had also taken a beta-adrenergic-blocker the same morning. Ten patients served as controls. The cross-sectional areas of a normal and a stenotic coronary vessel were determined by biplane quantitative coronary arteriography. RESULTS In the normal vessel segments, coronary cross-sectional area did not change after phentolamine injection, but increased in all patient groups similarly during exercise. Although coronary vasoconstriction existed in stenotic vessel segments in control patients, phentolamine-treated patients showed exercise-induced vasodilation without difference in Twenty-six patients were patients with and without chronic beta-blockade. CONCLUSIONS Exercise-induced vasoconstriction of stenotic coronary arteries is prevented by intracoronary administration of phentolamine There was no difference in coronary vasomotion between patients receiving phentolamine alone;md patients receiving phentolamine in addition to a beta-blocker. This finding suggests that exercise-induced vasoconstriction is mediated not only by endothelial dysfunction but also by alpha-adrenergic mechanisms. (C) 1999 by the American College of Cardiology.