Valentín A, Cardamone L, Baek S, Humphrey J D
Department of Biomedical Engineering, 337 Zachry Engineering Center, 3120 TAMU, Texas A&M University, College Station, TX 77843-3120, USA.
J R Soc Interface. 2009 Mar 6;6(32):293-306. doi: 10.1098/rsif.2008.0254.
Arteries exhibit a remarkable ability to adapt to sustained alterations in biomechanical loading, probably via mechanisms that are similarly involved in many arterial pathologies and responses to treatment. Of particular note, diverse data suggest that cell and matrix turnover within vasoaltered states enables arteries to adapt to sustained changes in blood flow and pressure. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodelling work together to adapt the geometry, structure, stiffness and function of a representative basilar artery. Towards this end, we employ a continuum theory of constrained mixtures to model evolving changes in the wall, which depend on both wall shear stress-induced changes in vasoactive molecules (which alter smooth muscle proliferation and synthesis of matrix) and intramural stress-induced changes in growth factors (which alter cell and matrix turnover). Simulations show, for example, that such considerations help explain the different rates of experimentally observed adaptations to increased versus decreased flows as well as differences in rates of change in response to increased flows or pressures.
动脉表现出显著的能力来适应生物力学负荷的持续变化，可能是通过与许多动脉病理和治疗反应同样相关的机制。特别值得注意的是，各种数据表明，血管改变状态下的细胞和基质更新使动脉能够适应血流和压力的持续变化。本文的目标是明确展示平滑肌收缩性的改变以及基质生长和重塑如何共同作用，以适应代表性基底动脉的几何形状、结构、刚度和功能。为此，我们采用约束混合物的连续介质理论来模拟血管壁的演变变化，这些变化既取决于壁面剪应力引起的血管活性分子变化（这会改变平滑肌增殖和基质合成），也取决于壁内应力引起的生长因子变化（这会改变细胞和基质更新）。例如，模拟结果表明，这些考虑有助于解释实验观察到的对流量增加与减少的不同适应速率，以及对流量或压力增加的反应变化速率差异。
