Kugiyama K, Ohgushi M, Motoyama T, Sugiyama S, Soejima H, Matsumura T, Yoshimura M, Ogawa H, Yasue H
Division of Cardiology, Kumamoto University School of Medicine, Kumamoto City, Japan.
J Cardiovasc Pharmacol. 1999 Mar;33(3):414-9. doi: 10.1097/00005344-199903000-00011.
This study examined the direct response of smooth muscle of coronary spasm sites to alpha1-adrenergic stimulation in patients with coronary spastic angina. Phenylephrine (1 microM in the coronary circulation, for 5 min), a stimulator of alpha1-adrenoreceptors, was directly infused into coronary arteries with spasm in 10 patients with coronary spastic angina and into normal coronary arteries in 10 control patients. The luminal diameter of epicardial coronary arteries was determined by computer-assisted quantitative angiography. The constrictor response to intracoronary injection of acetylcholine (ACh; 50 microg) was greater in spastic arteries than in control arteries (decrease from baseline, 48+/-2% vs. 12+/-2%, respectively; p<0.001). ACh (50 or 100 microg) induced coronary spasm associated with myocardial ischemia in all of patients with coronary spastic angina but not in any control patients. On the other hand, phenylephrine infusion did not induce coronary spasm in any of patients with coronary spastic angina or in control subjects. The constrictor response to phenylephrine infusion was comparable between spasm and control coronary arteries (decrease from baseline, 11+/-2% vs. 9+/-2%, respectively; p = NS). The results indicate that smooth muscle of spastic coronary arteries does not exhibit enhancement of constrictor response to direct stimulation of alpha1-adrenoreceptor on coronary smooth muscle. There may be receptor-specific enhancement of constrictor response to agonists in smooth muscle of spastic coronary arteries in patients with coronary spastic angina.
本研究检测了冠状动脉痉挛部位平滑肌对α1-肾上腺素能刺激的直接反应，研究对象为冠状动脉痉挛性心绞痛患者。将α1-肾上腺素能受体激动剂去氧肾上腺素（冠状动脉循环中浓度为1微摩尔，持续5分钟）直接注入10例冠状动脉痉挛性心绞痛患者的痉挛冠状动脉以及10例对照患者的正常冠状动脉。采用计算机辅助定量血管造影术测定心外膜冠状动脉的管腔直径。冠状动脉内注射乙酰胆碱（ACh；50微克）后，痉挛动脉的收缩反应大于对照动脉（相对于基线的下降幅度分别为48±2%和12±2%；p<0.001）。ACh（50或100微克）在所有冠状动脉痉挛性心绞痛患者中均诱发了与心肌缺血相关的冠状动脉痉挛，但在任何对照患者中均未诱发。另一方面，去氧肾上腺素输注在任何冠状动脉痉挛性心绞痛患者或对照受试者中均未诱发冠状动脉痉挛。痉挛冠状动脉和对照冠状动脉对去氧肾上腺素输注的收缩反应相当（相对于基线的下降幅度分别为11±2%和9±2%；p=无显著性差异）。结果表明，痉挛冠状动脉的平滑肌对冠状动脉平滑肌α1-肾上腺素能受体的直接刺激未表现出收缩反应增强。冠状动脉痉挛性心绞痛患者痉挛冠状动脉平滑肌对激动剂的收缩反应可能存在受体特异性增强。
