Adrenergic Receptor Activity in the Coronary Arteries of the Unanesthetized Dog
Adrenergic Receptor Activity in the Coronary Arteries of the Unanesthetized Dog
复制标题
未麻醉狗冠状动脉中的肾上腺素受体活性
作者：
B. Pitt;Eric C. Elliot;D. E. Gregg
未麻醉犬冠状动脉中α-（血管收缩剂）和β-（血管舒张剂）受体的活性不依赖于心肌中的肾上腺素能受体。在β受体阻断的动物中，静脉和冠状动脉内注射肾上腺素和去甲肾上腺素后，α-肾上腺素受体的活性表现为冠状动脉血管收缩，阻断α-肾上腺素受体可消除冠状动脉血管收缩。静脉注射苯肾上腺素和冠状动脉内注射去甲肾上腺素后，在β受体阻断前也可观察到冠状动脉收缩。在静脉注射或冠状动脉内注射儿茶酚胺后，在心肌或全身血流动力学发生任何变化之前，β-肾上腺素能受体的活性在最初的血管舒张中被证实。β-肾上腺素能受体阻断可以消除这种舒张。这种独立的肾上腺素能受体活性在控制冠状动脉循环中的作用仍有待确定。
Both α- (vasoconstrictor) and β- (vasodilator) receptor activity was demonstrated in the coronary arteries of the unanesthetized dog independent of adrenergic receptors in the myocardium. In the β-receptor blocked animal, α-adrenergic receptor activity was demonstrated after intravenous and intracoronary injections of epinephrine and norepinephrine by the occurrence of coronary vasoconstriction which could be eliminated by blocking α-adrenergic receptors as well. Coronary vasoconstriction was also seen prior to β-receptor blockade after intravenous phenylephrine and, on occasion, after intracoronary injections of norepinephrine. β-adrenergic receptor activity was demonstrated in several instances after intravenous or intracoronary injections of catecholamines by an initial vasodilatation which could be eliminated by β-adrenergic receptor blockade and which occurred before there was any change in myocardial or systemic hemodynamics. The role of this independent adrenergic receptor activity in the control of the coronary circulation remains to be determined.