Wall shear stress as measured in vivo: consequences for the design of the arterial system.
Wall shear stress as measured in vivo: consequences for the design of the arterial system.
复制标题
体内测量的壁剪应力：动脉系统设计的后果。
DOI：
10.1007/s11517-008-0330-2
复制
发表时间：
2008-05
影响因子：
3.2
通讯作者：
Hoeks, Arnold P. G.
中科院分区：
文献类型：
--
作者：
Reneman, Robert S.;Hoeks, Arnold P. G.
关键词：
基于理论，壁切应力（WSS），内皮功能和基因表达的重要决定因素，已被假定为恒定的沿着动脉树和跨物种的特定动脉相同。然而，WSS的体内测量结果表明，这些假设是远远不能成立的。在这项调查中，我们将讨论在体内动脉系统的WSS的评估，并提出在大动脉和小动脉中获得的结果。体内WSS可以从壁剪切速率估计，如从非侵入性记录的速度曲线，以及大动脉中的全血粘度和小动脉中的血浆粘度，避免理论假设。在大动脉中，可以通过专门设计的超声系统记录速度分布，在小动脉中，可以通过使用荧光流速示踪剂的光学技术记录速度分布。结果表明，在人类中，颈动脉中的平均WSS（1.1 - 1.3 Pa）显著高于肱动脉（0.4 - 0.5 Pa）和股动脉（0.3 - 0.5 Pa）。此外，在动物中，平均WSS沿动脉树显著沿着变化。在各种研究中，小动脉中的平均WSS在约1.0和5.0 Pa之间变化，并且取决于这些血管中的测量部位。跨物种，特定动脉中的平均WSS随体重线性降低，例如，在肾下主动脉中，从小鼠的8.8 Pa到人类的0.5 Pa。观察到平均WSS是远离恒定的沿着动脉树意味着默里的立方定律的流量直径的关系不能适用于整个动脉系统。因为血流速度沿动脉树也不是沿着恒定的，平方定律也不成立。幂律中的指数可能沿动脉系统沿着变化，可能从心脏附近的大动脉中的2变化到小动脉中的3。体内研究结果还表明，在体外研究中，不能采用平均剪切应力值来研究对不同血管区域或不同种属相同动脉内皮细胞的影响。细胞必须在它们在真实的生活中暴露的剪切应力条件下进行研究。
Based upon theory, wall shear stress (WSS), an important determinant of endothelial function and gene expression, has been assumed to be constant along the arterial tree and the same in a particular artery across species. In vivo measurements of WSS, however, have shown that these assumptions are far from valid. In this survey we will discuss the assessment of WSS in the arterial system in vivo and present the results obtained in large arteries and arterioles. In vivo WSS can be estimated from wall shear rate, as derived from non-invasively recorded velocity profiles, and whole blood viscosity in large arteries and plasma viscosity in arterioles, avoiding theoretical assumptions. In large arteries velocity profiles can be recorded by means of a specially designed ultrasound system and in arterioles via optical techniques using fluorescent flow velocity tracers. It is shown that in humans mean WSS is substantially higher in the carotid artery (1.1–1.3 Pa) than in the brachial (0.4–0.5 Pa) and femoral (0.3–0.5 Pa) arteries. Also in animals mean WSS varies substantially along the arterial tree. Mean WSS in arterioles varies between about 1.0 and 5.0 Pa in the various studies and is dependent on the site of measurement in these vessels. Across species mean WSS in a particular artery decreases linearly with body mass, e.g., in the infra-renal aorta from 8.8 Pa in mice to 0.5 Pa in humans. The observation that mean WSS is far from constant along the arterial tree implies that Murray’s cube law on flow-diameter relations cannot be applied to the whole arterial system. Because blood flow velocity is not constant along the arterial tree either, a square law also does not hold. The exponent in the power law likely varies along the arterial system, probably from 2 in large arteries near the heart to 3 in arterioles. The in vivo findings also imply that in in vitro studies no average shear stress value can be taken to study effects on endothelial cells derived from different vascular areas or from the same artery in different species. The cells have to be studied under the shear stress conditions they are exposed to in real life.
登录
查看更多内容
影响因子：
--
作者：
ARTS, T;KRUGER, RTI;RENEMAN, RS
通讯作者：
RENEMAN, RS
影响因子：
5.5
作者：
Bakker, ENTP;Versluis, JP;VanBavel, E
通讯作者：
VanBavel, E
影响因子：
2.9
作者：
BRANDS, PJ;HOEKS, APG;RENEMAN, RS
通讯作者：
RENEMAN, RS
影响因子：
1.7
作者：
Busse, R;Fleming, I
通讯作者：
Fleming, I
影响因子：
56.9
作者：
LABARBERA, M
通讯作者：
LABARBERA, M