Kashiki M, Yokoyama M, Fukuzaki H
First Department of Medicine, Kobe University School of Medicine, Japan.
Jpn Heart J. 1989 Nov;30(6):853-61. doi: 10.1536/ihj.30.853.
The coronary hemodynamic effects of propranolol (0.1 mg/kg, i.v.) were examined in anesthetized dogs with flow-limiting dynamic and fixed coronary stenosis of the left circumflex coronary artery. During fixed coronary stenosis created by external application of an occluder device, propranolol significantly decreased coronary blood flow (CBF) by 6.8 +/- 2.7% (mean +/- SEM, p less than 0.05) and increased mean distal coronary pressure (DCP) by 7 +/- 2.1 mmHg (p less than 0.05). This resulted in a decrease in stenosis resistance (SR) by 26 +/- 3.1% (p less than 0.01) due to oxygen demand reduction. By contrast, during dynamic coronary stenosis produced by an intraluminal microballoon occluder, propranolol decreased CBF by 68 +/- 3.4% (p less than 0.01) and mean DCP by 36 +/- 4.2 mmHg (p less than 0.01), resulting in an increase in SR by 694 +/- 109% (p less than 0.01). This increase in SR was attenuated by pretreatment with an alpha-adrenergic receptor antagonist phentolamine (0.5 mg/kg, i.v.), or by holding heart rate constant at the pretreatment level. These results suggest that propranolol ameliorated the severity of stenosis during fixed coronary stenosis and exacerbated the severity during dynamic coronary stenosis. This increase in SR appears to be related to vasoconstriction of the large stenosed coronary artery, mediated both by alpha-adrenergic receptors in the coronary artery and by myocardial oxygen demand reduction.
在麻醉犬身上，研究了普萘洛尔（0.1毫克/千克，静脉注射）对左旋冠状动脉存在血流限制性动态和固定性狭窄时的冠状动脉血流动力学影响。在通过外部应用封堵装置造成固定性冠状动脉狭窄期间，普萘洛尔使冠状动脉血流量（CBF）显著降低6.8±2.7%（平均值±标准误，p<0.05），并使冠状动脉远端平均压（DCP）升高7±2.1毫米汞柱（p<0.05）。由于氧需求降低，这导致狭窄阻力（SR）降低26±3.1%（p<0.01）。相比之下，在通过腔内微球囊封堵器造成动态冠状动脉狭窄期间，普萘洛尔使CBF降低68±3.4%（p<0.01），使平均DCP降低36±4.2毫米汞柱（p<0.01），导致SR升高694±109%（p<0.01）。预先用α-肾上腺素能受体拮抗剂酚妥拉明（0.5毫克/千克，静脉注射）预处理，或使心率保持在预处理水平不变，可减弱SR的这种升高。这些结果表明，普萘洛尔在固定性冠状动脉狭窄期间减轻了狭窄严重程度，而在动态冠状动脉狭窄期间加重了狭窄严重程度。SR的这种升高似乎与严重狭窄的冠状动脉的血管收缩有关，这是由冠状动脉中的α-肾上腺素能受体和心肌氧需求降低介导的。
