Effects of norepinephrine on the mechanical properties of the human radial artery in vitro
Effects of norepinephrine on the mechanical properties of the human radial artery in vitro
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DOI：
10.1016/s0002-8703(98)70009-2
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发表时间：
1998-10-01
影响因子：
4.8
通讯作者：
Safar, ME
中科院分区：
文献类型：
--
作者：
Girerd, X;Chamiot-Clerc, P;Safar, ME
背景在冠状动脉缺血性疾病患者中，人桡动脉被提议作为冠状动脉移植物的替代物。因为这个肌肉动脉是已知的容易痉挛，其机械性能的变化，响应于儿茶酚胺是重要的调查。方法我们描述了一种新的回声跟踪技术的高分辨率，允许调查，在体外，动脉圆柱形段的直径和壁厚。此外，还使用经典的组织浴实验来研究动脉环的血管反应性。结果组织浴法测得去甲肾上腺素对桡动脉的量效曲线，其EC_（50）值为1.48 ± 1.09 × 10 ~（-6）mol/L，最大张力为10 ~（-5）mol/L。用加压节段获得的结果给出了类似的结果，EC 50值为8.1 +/- 2.3 × 10（-7）mol/L，在10（-5）mol/L去甲肾上腺素下直径变化最大。在10（-5）mol/L去甲肾上腺素的作用下，桡动脉收缩达22%，显著影响无应力直径。顺应性并没有表现出任何显着的变化，在整个跨壁压范围，而扩张性显着增加，弹性模量显着decreased.Conclusion研究表明，人肌桡动脉的电容特性与去甲肾上腺素保持不仅通过降低壁材料的刚度，但也通过减少无应力直径。因此，诱导平滑肌松弛的药物可能有助于预防冠状动脉移植术后桡动脉痉挛。
Background The human redial artery has been proposed as on alternative to coronary grafts in subjects with coronary ischemic disease. Because this muscular artery is known to be prone to spasm, changes in its mechanical properties in response to catecholamines are important to investigate.Methods We describe a new echo-tracking technique of high resolution that allows investigation, in vitro, of the diameter and the wall thickness of arterial cylindrical segments. In addition, a classic tissue bath experiment is used to study the vasoreactivity of arterial rings. Mechanical properties of the radial artery are determined over a 0 to 200 mm Hg range of transmural pressure in the presence and absence of norepinephrine in the perfusion medium.Results With tissue bath experiments, the norepinephrine dose-response curve was characterized by on EC50 value of 1.48 +/- 1.09 10(-6) mol/L and a maximal developed tension at 10(-5) mol/L. The results obtained with pressurized segments gave similar results with an EC50 value of 8.1 +/- 2.3 10(-7) mol/L and a maximal change in diameter at 10(-5) mol/L norepinephrine. Under the influence of 10(-5) mol/L norepinephrine, the radial artery constriction reached 22%, significantly affecting the unstressed diameter. Compliance did not show any significant change in the overall transmural pressure range, whereas distensibility significantly increased and elastic modulus significantly decreased.Conclusion The study shows that the capacitive properties of the human muscular radial artery are maintained with norepinephrine not only through decreased stiffness of wall material but also through reduced unstressed diameter. Thus drugs inducing smooth muscle relaxation may be helpful in preventing radial artery spasm after coronary grafts.