Jones C J, Lever M J, Parker K H, Ogasawara Y, Hiramatsu O, Tsujioka K, Takenaka T, Caro C G, Kajiya F
Physiological Flow Studies Group, Centre for Biological and Medical Systems, Imperial College of Science, Technology and Medicine, London, United Kingdom.
Cardiovasc Res. 1994 Nov;28(11):1686-93. doi: 10.1093/cvr/28.11.1686.
The aim was to study the effects of altered heart rate and vasoactive drugs on the blood velocity patterns in the region of an arterial bifurcation.
Blood velocity profiles were measured in an exposed iliofemoral bifurcation of paced dogs using a pulsed Doppler ultrasound velocimeter with high temporal and spatial resolution.
Decrease of the heart rate from 120 beats.min-1 (2 Hz) to 60 beats.min-1 (1 Hz) increased the peak forward velocity (30%), the peak reverse velocity (20%), and the duration of reverse flow (25%). Each drug caused qualitatively similar changes in velocity patterns at both heart rates. The systemic administration of angiotensin II reduced peak forward velocity (-26% at 2 Hz and -33% at 1 Hz) and forward flow duration (-15% at 1 Hz), the peak reverse velocity (-30% at 1 Hz), and reverse flow duration (-20% at 2 Hz and -28% at 1 Hz). Glyceryl trinitrate also reduced the peak forward velocity (-19% at both 2 and 1 Hz) but prolonged forward flow duration (28% at 2 Hz and 17% at 1 Hz) and that of reverse flow (45% at 2 Hz and 24% at 1 Hz), and also decreased the degree of oscillation (-16% at 2 Hz). Barnidipine hydrochloride (a calcium channel antagonist) also increased the duration of forward flow (48% at 1 Hz) and of reverse flow (31% at 2 Hz) but reduced the peak reverse velocity (-29% at 1 Hz) and flow oscillation (-22% at 2 Hz and 20% at 1 Hz).
These dramatic changes in the pattern of blood flow, including alterations in the amplitudes and durations of the different phases of the flow cycle, are expected to have important consequences on the shear dependent responses of endothelial cells in the region of the bifurcation.
研究心率改变及血管活性药物对动脉分叉区域血流速度模式的影响。
使用具有高时间和空间分辨率的脉冲多普勒超声测速仪，在起搏犬暴露的髂股动脉分叉处测量血流速度剖面。
心率从120次/分钟（2赫兹）降至60次/分钟（1赫兹），使正向峰值速度增加（30%）、反向峰值速度增加（20%）、反向血流持续时间增加（25%）。两种心率下，每种药物均引起速度模式的定性相似变化。静脉注射血管紧张素II可降低正向峰值速度（2赫兹时为-26%，1赫兹时为-33%）和正向血流持续时间（1赫兹时为-15%）、反向峰值速度（1赫兹时为-30%）以及反向血流持续时间（2赫兹时为-20%，1赫兹时为-28%）。硝酸甘油也降低正向峰值速度（2赫兹和1赫兹时均为-19%），但延长正向血流持续时间（2赫兹时为28%，1赫兹时为17%）和反向血流持续时间（2赫兹时为45%，1赫兹时为24%），并降低振荡程度（2赫兹时为-16%）。盐酸巴尼地平（一种钙通道拮抗剂）也增加正向血流持续时间（1赫兹时为48%）和反向血流持续时间（2赫兹时为31%），但降低反向峰值速度（1赫兹时为-29%）和血流振荡（2赫兹时为-22%，1赫兹时为20%）。
血流模式的这些显著变化，包括血流周期不同阶段的幅度和持续时间改变，预计会对分叉区域内皮细胞的剪切依赖性反应产生重要影响。
