Ohtsuka S, Kakihana M, Sugishita Y, Ito I
Jpn Heart J. 1987 May;28(3):403-12. doi: 10.1536/ihj.28.403.
In order to investigate the effect of a rise in aortic pressure on coronary flow reserve and also on the difference of its effect according to the methods used to raise aortic pressure, this experiment was performed. Using 7 anesthetized dogs with heart rate held constant by a pacemaker, both the resting and the peak reactive hyperemic left circumflex coronary flow were measured following raising of the aortic pressure by either descending thoracic aorta constriction or methoxamine injection. The resting and peak reactive hyperemic coronary flows both increased linearly following the rise in aortic pressure. The magnitude of the resting flow increment and the resting coronary vascular resistance following raising aortic pressure did not differ significantly between the two different methods. However, the magnitude of the peak hyperemic flow increment and the peak hyperemic coronary vascular resistance following raising aortic pressure were significantly smaller with methoxamine injection than with aortic constriction. These data indicate that coronary flow reserve increases proportionally with a rise in aortic pressure. However, the magnitude of the increment of coronary flow reserve is smaller following an alpha-adrenoceptor-mediated rise in aortic pressure, because the maximal coronary vasodilation was reduced by alpha-stimulated coronary vasoconstriction.
为了研究主动脉压力升高对冠状动脉血流储备的影响，以及根据升高主动脉压力的方法不同其影响的差异，进行了本实验。使用7只通过起搏器使心率保持恒定的麻醉犬，在通过降胸主动脉缩窄或注射甲氧明升高主动脉压力后，测量静息和峰值反应性充血状态下的左旋冠状动脉血流。随着主动脉压力升高，静息和峰值反应性充血冠状动脉血流均呈线性增加。两种不同方法升高主动脉压力后，静息血流增量的幅度和静息冠状动脉血管阻力无显著差异。然而，注射甲氧明后，升高主动脉压力后的峰值充血血流增量幅度和峰值充血冠状动脉血管阻力显著小于主动脉缩窄。这些数据表明，冠状动脉血流储备随主动脉压力升高而成比例增加。然而，α-肾上腺素能受体介导的主动脉压力升高后，冠状动脉血流储备的增量幅度较小，因为α刺激的冠状动脉血管收缩降低了最大冠状动脉血管舒张。
