Key Laboratory for Biomechanics and Mechanobiology of the Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, People's Republic of China.
J R Soc Interface. 2012 Oct 7;9(75):2468-78. doi: 10.1098/rsif.2012.0224. Epub 2012 May 16.
To test the hypothesis that disturbed flow can impede the transport of nitric oxide (NO) in the artery and hence induce atherogenesis, we used a lumen-wall model of an idealized arterial stenosis with NO produced at the blood vessel-wall interface to study the transport of NO in the stenosis. Blood flows in the lumen and through the arterial wall were simulated by Navier-Stokes equations and Darcy's Law, respectively. Meanwhile, the transport of NO in the lumen and the transport of NO within the arterial wall were modelled by advection-diffusion reaction equations. Coupling of fluid dynamics at the endothelium was achieved by the Kedem-Katchalsky equations. The results showed that both the hydraulic conductivity of the endothelium and the non-Newtonian viscous behaviour of blood had little effect on the distribution of NO. However, the blood flow rate, stenosis severity, red blood cells (RBCs), RBC-free layer and NO production rate at the blood vessel-wall interface could significantly affect the transport of NO. The theoretical study revealed that the transport of NO was significantly hindered in the disturbed flow region distal to the stenosis. The reduced NO concentration in the disturbed flow region might play an important role in the localized genesis and development of atherosclerosis.
为了验证这样一个假设，即紊乱的流动会阻碍动脉中一氧化氮（NO）的输送，从而导致动脉粥样硬化的形成，我们使用了一个理想化的动脉狭窄管腔-壁模型，在该模型中，NO 是在血管壁界面处产生的，以研究 NO 在狭窄处的输送情况。管腔中的血液流动和穿过动脉壁的血流分别通过纳维-斯托克斯方程和达西定律进行模拟。同时，NO 在管腔中的输送和 NO 在动脉壁内的输送通过对流-扩散反应方程进行建模。通过 Kedem-Katchalsky 方程实现了内皮处流体动力学的耦合。结果表明，内皮的水力传导率和血液的非牛顿粘性行为对 NO 的分布几乎没有影响。然而，血流速度、狭窄严重程度、红细胞（RBC）、无 RBC 层和血管壁界面处的 NO 产生速率会显著影响 NO 的输送。理论研究表明，NO 的输送在狭窄下游的紊乱流区受到显著阻碍。紊乱流区中 NO 浓度的降低可能在动脉粥样硬化的局部发生和发展中发挥重要作用。
