Dancu Michael B, Tarbell John M
Biomolecular Transport Dynamics Laboratory, Department of Bioengineering, The Pennsylvania State University, University Park, PA 16802, USA.
J Biomech Eng. 2006 Jun;128(3):329-34. doi: 10.1115/1.1824120.
Hemodynamics plays an important role in cardiovascular physiology and pathology. Pulsatile flow (Q), pressure (P), and diameter (D) waveforms exert wall shear stress (WSS), normal stress, and circumferential strain (CS) on blood vessels. Most in vitro studies to date have focused on either WSS or CS but not their interaction. Recently, we have shown that concomitant WSS and CS affect EC biochemical response modulated by the temporal phase angle between WSS and CS (stress phase angle, SPA). Large negative SPA has been shown to occur in regions of the circulation where atherosclerosis and intimal hyperplasia are prevalent. Here, we report that nitric oxide (NO) biochemical secretion was significantly decreased in response to a large negative SPA of -180 deg with respect to an SPA of 0 degrees in bovine aortic endothelial cells (BAEC) at 5 h. A new hemodynamic simulator for the study of the physiologic SPA was used to provide the hemodynamic conditions of pro-atherogenic (SPA = -180 deg) and normopathic (SPA = 0 deg) states. The role of complex hemodynamics in vascular remodeling, homeostasis, and pathogenesis can be advanced by further assessment of the hypothesis that a large negative SPA is pro-atherogenic.
血流动力学在心血管生理学和病理学中起着重要作用。脉动流（Q）、压力（P）和直径（D）波形对血管施加壁面剪应力（WSS）、法向应力和周向应变（CS）。迄今为止，大多数体外研究都集中在WSS或CS上，而不是它们之间的相互作用。最近，我们已经表明，伴随的WSS和CS会影响由WSS和CS之间的时间相位角（应力相位角，SPA）调节的内皮细胞生化反应。已证明在动脉粥样硬化和内膜增生普遍存在的循环区域会出现大的负SPA。在此，我们报告，在5小时时，相对于0度的SPA，牛主动脉内皮细胞（BAEC）中，响应于-180度的大负SPA，一氧化氮（NO）生化分泌显著减少。一种用于研究生理SPA的新型血流动力学模拟器被用于提供促动脉粥样硬化（SPA = -180度）和正常状态（SPA = 0度）的血流动力学条件。通过进一步评估大负SPA具有促动脉粥样硬化作用这一假设，可以推进复杂血流动力学在血管重塑、内环境稳定和发病机制中的作用。
