Modelling carotid artery adaptations to dynamic alterations in pressure and flow over the cardiac cycle
Modelling carotid artery adaptations to dynamic alterations in pressure and flow over the cardiac cycle
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DOI：
10.1093/imammb/dqq001
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发表时间：
2010-12-01
影响因子：
1.1
通讯作者：
Humphrey, J. D.
中科院分区：
文献类型：
--
作者：
Cardamone, L.;Valentin, A.;Humphrey, J. D.
受脉动压力和血流对动脉适应性的重要影响的近期临床和实验室研究结果的激励，我们采用并扩展了已建立的生长（质量变化）和重塑（结构变化）的约束混合框架，以包括这种动态影响。新的描述细胞和组织的行为（本构关系）的假设和完善基于新的实验数据，从横动脉弓带带模型在小鼠，增加脉冲压力和流量在一个颈动脉。特别是，研究表明，有必要完善平滑肌产生的主动应力的本构关系，包括应力和应力率介导的细胞和基质周转控制，并考虑循环应力介导的弹性纤维完整性损失和胶原硬度降低，以便捕获报道的进化，超过8周，管腔半径，壁厚，高血压小鼠颈动脉的轴向力和体内轴向拉伸。因此，我们认为弹性动脉适应的复杂方面可以通过约束混合模型来预测，其中个体成分以个体速率和个体程度产生或去除，这取决于应力和应力速率从正常值的变化。
Motivated by recent clinical and laboratory findings of important effects of pulsatile pressure and flow on arterial adaptations, we employ and extend an established constrained mixture framework of growth (change in mass) and remodelling (change in structure) to include such dynamical effects. New descriptors of cell and tissue behavior (constitutive relations) are postulated and refined based on new experimental data from a transverse aortic arch banding model in the mouse that increases pulsatile pressure and flow in one carotid artery. In particular, it is shown that there was a need to refine constitutive relations for the active stress generated by smooth muscle, to include both stress- and stress rate-mediated control of the turnover of cells and matrix and to account for a cyclic stress-mediated loss of elastic fibre integrity and decrease in collagen stiffness in order to capture the reported evolution, over 8 weeks, of luminal radius, wall thickness, axial force and in vivo axial stretch of the hypertensive mouse carotid artery. We submit, therefore, that complex aspects of adaptation by elastic arteries can be predicted by constrained mixture models wherein individual constituents are produced or removed at individual rates and to individual extents depending on changes in both stress and stress rate from normal values.