Leukocytes rolling and recruitment by endothelial cells: Hemorheological experiments and numerical simulations
Leukocytes rolling and recruitment by endothelial cells: Hemorheological experiments and numerical simulations
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DOI：
10.1016/j.jbiomech.2007.05.031
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发表时间：
2007-01-01
影响因子：
2.4
通讯作者：
Saldanha, C.
中科院分区：
文献类型：
--
作者：
Artoli, A. M.;Sequeira, A.;Saldanha, C.
白细胞从血流中的募集及其随后粘附到内皮壁是炎症期间免疫应答系统的重要阶段。分子介质促进白细胞停滞的精确动力学机制仍然未知。在这项研究中，结合实验结果和计算机模拟研究局部流体力学的个人和集体行为的白细胞集群。用活体显微镜观察了Wistar大鼠提睾肌毛细血管后微静脉中白细胞与内皮细胞的相互作用。从这些实验中的血液流变学和血液动力学测量参数中使用的时间依赖性的三维计算机模拟，使用介观格子Boltzmann流动求解器的剪切稀化流体。计算并讨论了具有剪切变稀粘度的广义牛顿流体中白细胞团的动力学行为。在本文中，我们提出了定量的白细胞表面和血管壁附着点附近的速度和剪切应力的分布。我们已经观察到一个区域的最大剪切应力和两个区域的最小剪切应力的表面上的白细胞靠近内皮壁。我们证实了募集的白细胞簇的集体流体动力学行为建立了额外白细胞募集的强烈动机。有人发现，这里使用的格子玻尔兹曼求解器是完全自适应的测量的实验参数。本研究提示，白细胞滚动对内皮细胞壁切应力增加的影响可能支持炎症过程中更多信号介质的激活。(c)2007爱思唯尔有限公司保留所有权利。
The recruitment of leukocytes from the blood stream and their subsequent adhesion to endothelial walls are essential stages to the immune response system during inflammation. The precise dynamic mechanisms by which molecular mediators facilitate leukocyte arrests are still unknown. In this study combined experimental results and computer simulations are used to investigate localized hydrodynamics of individual and collective behavior of clusters of leukocytes. Leukocyte-endothelial cell interactions in post-capillary venules of Wistar rats cremaster muscle were monitored by intravital microscopy. From these experiments the hemorheologic and hemodynamical measured parameters were used in time dependent three-dimensional computer simulations, using a mesoscopic lattice Boltzmann flow solver for shear thinning fluids. The dynamics of leukocyte clusters under generalized Newtonian blood flow with shear thinning viscosity was computed and discussed. In this paper we present quantified distributions of velocity and shear stress on the surface of leukocytes and near vessel wall attachment points. We have observed one region of maximum shear stress and two regions of minimum shear stress on the surface of leukocytes close to the endothelial wall. We verified that the collective hydrodynamic behavior of the cluster of recruited leukocytes establishes a strong motive for additional leukocyte recruitment. It was found that the lattice Boltzmann solver used here is fully adaptive to the measured experimental parameters. This study suggests that the influence of the leukocytes rolling on the increase of the endothelial wall shear stress may support the activation of more signalling mediators during inflammation. (c) 2007 Elsevier Ltd. All rights reserved.