Hall C L, Taubman M B, Nemerson Y, Turitto V T
Biomedical Engineering Department, University of Memphis, TN 38152-6582, USA.
J Biomech Eng. 1998 Aug;120(4):484-90. doi: 10.1115/1.2798018.
The purpose of the present investigation was to explore the effects of well-defined flow conditions on the activity of tissue factor (TF) expressed on the surface of cultured rat vascular smooth muscle cells. Cells were cultured to confluence on Permanox brand slides and stimulated to express TF by a 90 min incubation with fresh growth medium containing 10 percent calf serum. The stimulated cells were then placed in a parallel plate flow chamber and perfused with Hank's Balanced Salt Solution containing factor VIIa, factor X (FX), and calcium. The chamber effluent was collected and assayed for factor Xa (FXa) and the steady-state flux of FXa was calculated. The flux values were 68.73, 94.81, 139.75, 138.19, 316.82, and 592.92 fmole/min/cm2 at wall shear rates of 10, 20, 40, 80, 320, and 1280 s-1, respectively. The FXa flux depended on the wall shear rate to a greater degree than predicted by classical mass transport theory. The flux at each shear rate was three to five times less than that calculated according to the Leveque solution. These features of the experimental data imply nonclassical behavior, which may partially result from a direct effect of flow on the cell layer.
本研究的目的是探讨明确的流动条件对培养的大鼠血管平滑肌细胞表面表达的组织因子（TF）活性的影响。将细胞培养至在Permanox品牌载玻片上汇合，并用含有10%小牛血清的新鲜生长培养基孵育90分钟以刺激其表达TF。然后将受刺激的细胞置于平行板流动腔室中，并用含有因子VIIa、因子X（FX）和钙的汉克平衡盐溶液进行灌注。收集腔室流出物并测定因子Xa（FXa），并计算FXa的稳态通量。在壁面剪切速率分别为10、20、40、80、320和1280 s-1时，通量值分别为68.73、94.81、139.75、138.19、316.82和592.92 fmol/min/cm2。FXa通量对壁面剪切速率的依赖程度比经典传质理论预测的更大。每个剪切速率下的通量比根据勒维克解计算的值小三到五倍。实验数据的这些特征意味着非经典行为，这可能部分是由于流动对细胞层的直接影响所致。
