MICROVASCULAR DISTRIBUTION OF CORONARY VASCULAR-RESISTANCE IN BEATING LEFT-VENTRICLE
MICROVASCULAR DISTRIBUTION OF CORONARY VASCULAR-RESISTANCE IN BEATING LEFT-VENTRICLE
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DOI：
10.1152/ajpheart.1986.251.4.h779
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发表时间：
1986-10-01
影响因子：
--
通讯作者：
MARCUS, ML
中科院分区：
文献类型：
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作者：
CHILIAN, WM;EASTHAM, CL;MARCUS, ML
为了确定阻力在冠状动脉血管系统中的分布，在血管紧张素完整和罂粟碱产生的冠状动脉扩张期间获得微血管压力和直径的测量值。我们研究了麻醉开胸猫，并使用与心动周期同步的喷射通气来消除麻醉诱导的心脏运动。用于测量微血管压力的系统通过微血管的频闪照明和计算机控制的机电显微操作器来补偿心脏运动，所述机电显微操作器与热同步移动微量移液管。用servonull技术测量压力，并通过视频系统测量直径。根据从主动脉到特定类别（尺寸）的冠状动脉微血管的压力梯度估计阻力。在对照条件下，冠状动脉血管张力完整，心肌灌注为139 . ±. 9 ml. min-1. 100 g-1，并增加至139 . ±.罂粟碱组52例（P < 0.05）。在控制条件下（平均动脉压70-80 mmHg），总冠状动脉阻力的25%接近200 μ m直径的小动脉和20%由直径在100和200 μ m之间的小动脉产生; 20-从主动脉到200-μ m小动脉的压力梯度为30- 35-mmHg，从主动脉到100-μ m小动脉的压力梯度为30- 35-mmHg。目前的结果还表明，在对照条件下，总冠状动脉阻力的55%在100 μ m小动脉的远端。用罂粟碱进行的冠状血管舒张（用主动脉勒除器将平均动脉压维持在70-75 mmHg）产生阻力的重新分布;在200 μ m小动脉的近端仅为总阻力的10%，并且从主动脉到这些血管的压力梯度仅为5-10 mmHg。因此，在血管紧张素完整的这些实验条件下，相当大部分（45%）的冠状动脉阻力残留在相对大（> 100 μ m）的冠状动脉中，并且阻力和微血管压力的分布可以随着冠状动脉血管舒张而改变。
To determine the distribution of resistance in the coronary vasculature, measurements of microvasculature pressure and diameter were obtained with vasomotor tone intact and during coronary dilation produced by papaverine. We studied anesthtetized, open-chest cats and used jet ventilation synchronized to the cardiac cycle to eliminate respiratory-induced cardiac motion. The system for measuring microvascular pressure compensated for cardiac motion with stroboscopic illumination of the microvessels and a computer-controlled electromechanical micromanipulator that moved a micropipette in synchrony with the heat. Pressures were measured with the servonull technique and diameters were measured via a video system. Resistance was estimated from the pressure gradient from the aorta to a particular class (size) of coronary microvessel. During control conditions, with coronary vasomotor tone intact, myocardial perfusion was 139 .+-. 9 ml .cntdot. min-1 .cntdot. 100 g-1 and was increased to 139 .+-. 52 during papaverine infusion (P < 0.05). During control conditions (mean arterial pressure 70-80 mmHg), .apprx. 25% of total coronary resistance was proximal to 200-.mu.m-diameter arterioles and .apprx. 20% was produced by arterioles between 100 and 200 .mu.m diameter; there was .apprx. 20-mmHg pressure gradient from the aorta to 200-.mu.m arterioles and 30- to 35-mmHg gradient from the aorta to 100-.mu.m arterioles. Present results also indicate that 55% of total coronary resistance is distal to the 100-.mu.m arterioles under control conditions. Coronary vasodilation with papaverine (mean arterial pressure maintained at 70-75 mmHg with an aortic snare) produced a redistribution of resistance; only 10% of total resistance as proximal to the 200-.mu.m arterioles, and the pressure gradient from the aorta to these vessels was only 5-10 mmHg. Thus, under these experimental conditions with vasomotor tone intact, a substantial portion (45%) of coronary resistance residues in relatively large (> 100-.mu.m) coronary arterioles, and the distribution of resistance and microvascular pressure can be shifted with coronary vasodilation.