Sakamoto S, Yokoyama M, Fukuzaki H
Jpn Circ J. 1986 May;50(5):416-25. doi: 10.1253/jcj.50.416.
In order to evaluate the role of adrenergic receptor-mediated vasomotions of large epicardial coronary arteries in changing coronary blood flow (CBF), the effects of intracoronary norepinephrine (NE), 1.0 microgram/min, were examined in dogs with coronary stenosis which preserved stenosis vasomobility. In untreated dogs, NE caused no significant changes in CBF and stenosis resistance (SR). In dogs treated with propranolol, NE decreased CBF by 65 +/- 7.0% (mean +/- SE) and produced 12-fold intensification of SR followed by LV dP/dt reduction. Similar detrimental responses to NE were observed in dogs treated with atenolol. In dogs treated with phentolamine, NE increased CBF by 33 +/- 5.6% and decreased SR by 65 +/- 7.1%. When NE was administrated directly distal to the stenosis to exclude responses of the stenosed coronary segment, NE failed to affect CBF and SR. These results indicated that alpha receptor stimulation intensified stenosis severity, profoundly decreased CBF and evoked myocardial ischemia, whereas beta stimulation dilated coronary stenosis and increased CBF. The net effects of NE were due to balanced alpha and beta stimulation. Thus, disproportionate activation of alpha and beta (probably beta 1) adrenergic receptors in large coronary arteries with pliable stenosis could modulate their tone and plays an important role in the regulation of CBF.
为了评估肾上腺素能受体介导的大的心外膜冠状动脉血管运动在改变冠状动脉血流量（CBF）中的作用，在保留狭窄血管运动性的冠状动脉狭窄犬中，检测了每分钟1.0微克冠状动脉内去甲肾上腺素（NE）的作用。在未治疗的犬中，NE对CBF和狭窄阻力（SR）无显著影响。在普萘洛尔治疗的犬中，NE使CBF降低65±7.0%（平均值±标准误），并使SR增强12倍，随后左室dp/dt降低。在阿替洛尔治疗的犬中观察到对NE的类似有害反应。在酚妥拉明治疗的犬中，NE使CBF增加33±5.6%，并使SR降低65±7.1%。当在狭窄远端直接给予NE以排除狭窄冠状动脉段的反应时，NE未能影响CBF和SR。这些结果表明，α受体刺激加剧狭窄程度，显著降低CBF并诱发心肌缺血，而β受体刺激则扩张冠状动脉狭窄并增加CBF。NE的净效应归因于α和β刺激的平衡。因此，在具有柔韧性狭窄的大冠状动脉中，α和β（可能是β1）肾上腺素能受体的不均衡激活可调节其张力，并在CBF调节中起重要作用。
