用复合液滴模型研究稳定剪切流动下黏附于血管表面白细胞的变形  

Study on the Deformation of Leukocyte Adhered to Vascular Surface Under Steady Shear Flow By Using a Compound Drop Model

作　　者：刘肖珩[1] Xiong Wang 尹红梅[3] 

机构地区：[1]四川大学华西医学中心生物医学工程研究室,成都610041 [2]LEMTA-UMR-CNRS7563,Vandoeuvreles Nancy,France [3]四川大学华西药学院,成都610041

出　　处：《北京生物医学工程》2003年第4期274-277,共4页Beijing Biomedical Engineering

基　　金：中国国家自然科学基金 ( 10 10 2 0 12 );FrenchMinistryofResearchGrantPost DocNo2 71资助课题

摘　　要：变形作用是黏附于血管表面的白细胞响应外界流体作用的重要特征 ,然而 ,尚不清楚白细胞的细胞核是否伴随细胞而发生变形。我们用复合液滴模拟黏附于血管表面的白细胞 ,根据二维计算流体动力学方法研究稳定剪切流动下白细胞及其细胞核发生变形的生物力学机制。结果表明 :(1 )外界流场雷诺数是引起细胞变形的重要原因。随着雷诺数的增大 ,细胞变形也增大 ;(2 )细胞核随细胞的变形而发生了变形 ,但细胞的变形指数总是大于其细胞核 ,表明细胞核更能耐受剪切流动 ;(3)当雷诺数增大到一定值时 ,细胞和细胞核都不能进一步变形 ,变形指数达到峰值 ;(4 )压力分布曲线表明 ,在细胞的下游形成一个高压区 ,提供促使细胞受力达到平衡的升力 ,从而阻止了细胞的进一步变形。因此 ,具有高粘性的细胞核在细胞的变形过程中发挥特殊作用。It is well known that the deformation is a key feature of a leukocyte adhered to vascular surface in response to external mechanical forces exerted by a flow. However, it remains to be elucidated that if the nucleus deforms at the same times when the leukocyte deforms. In this study, we propose a compound drop model to simulate a leukocyte with a nucleus adhered to the surface of blood vessel. A two dimensional method to compute fluid dynamics (CFD) is conducted to investigate the bio mechanical deformation of the leukocyte and it′s nucleus under steady shear flow. Our results show that: (1) The Reynold′s number of external shear flow plays a crucial role in leukocyte deformation.The greater the Reynold′s number is, the greater is the cell deformation. (2) The nucleus deforms at the same time with the leukocyte, and the deformation index of the leukocyte is greater than that of the nucleus. The leukocyte is easier to deform while the nucleus is more capable of resisting external shear flow.(3)The leukocyte and the nucleus can′t deform without any limit with the increase of Reynold′s number, and the deformation index has a limitofmaximum.(4) Pressure distribution curve confirms that there exists a region downstream of the cell, which produces high pressure, provides a positive lift force on the cell and retards continuous deformation.Therefore, the nucleus with high viscosity plays a particular role in the process of leukocyte deformation.

关 键 词：变形作用 血管表面 白细胞 复合液滴模型 外界流体 流体动力学 生物力学 

分 类 号：R318.01[医药卫生—生物医学工程]