Chapman G, Cokelet G
Department of Biophysics, University of Rochester, New York 14642, USA.
Biorheology. 1996 Mar-Apr;33(2):119-38. doi: 10.1016/0006-355X(96)00011-X.
Using a large scale model and the concept of dimensional similarity, we have developed a dimensionless correlation which permits the estimation of the drag force of blood flow in an in vivo vessel on a leukocyte adherent to the vessel wall. This relationship is [formula: see text] where Re is a Reynolds number, Cd is a drag coefficient, and d/D is the leukocyte-to-vessel diameter ratio. This function increases rapidly with increasing d/D when d/D is greater than 0.5. A relationship between the drag force on the leukocyte, Ff, and the commonly used wall shear stress in the absence of the adherent cell, tau w, has also been developed, and is given by [formula: see text] This study shows that the discrepancy between the in vivo and in vitro critical wall stresses (above which leukocytes do not adhere to endothelial cell layers) is not due to misrepresentation of the corresponding drag forces on the leukocytes. The discrepancy must be due to real differences in the flow and/or cellular conditions between the in vivo and in vitro experiments.
利用一个大规模模型和尺寸相似性的概念，我们开发了一个无量纲关联式，该关联式允许估算体内血管中血流对附着于血管壁的白细胞的阻力。这种关系为[公式：见正文]，其中Re是雷诺数，Cd是阻力系数，d/D是白细胞与血管直径之比。当d/D大于0.5时，该函数随d/D的增加而迅速增加。还建立了白细胞上的阻力Ff与无附着细胞时常用的壁面剪应力τw之间的关系，其表达式为[公式：见正文]。本研究表明，体内和体外临界壁面应力（高于此应力白细胞不粘附于内皮细胞层）之间的差异并非由于对白细胞上相应阻力的错误表述。这种差异必定是由于体内和体外实验中血流和/或细胞条件的实际差异所致。
