摘要目的 观察血管分叉顶点处的血流切应力(WSS)对内皮细胞的影响.方法 利用改进的灌流及T型流动腔装置,通过调节蠕动泵的转速和流量调节阀来控制冲击力大小,建立模拟血管分叉顶点处血流作用下的内皮细胞培养系统.对体外培养的内皮细胞加载流速为250 ml/min[相当于雷诺数(Re)=125]至500 ml/min(Re=250)的稳定剪应力冲击流,观察不同作用时间(3、6、12 h)内皮细胞层的形态学特征.结果 加载250 ml/min的流速下,作用3、6、12 h后冲击点及其周围的细胞仍维持着多边形.而加载流速500 ml/min,12h后,可见高WSS和高切应力梯度(WSSG)区的细胞密度下降且形态被拉长,排列与冲击流方向平行一致,部分细胞向下游迁徙;且内皮细胞形态学变化不受细胞增殖抑制剂影响,表明细胞从驻点向下游迁徙是流体作用的结果.结论 改进的细胞流体力学实验装置能模拟体内血流冲击环境,具有冲击力调控方便和安全可靠的优点,能作为研究血管分叉处(颅内动脉瘤好发部位)血流环境下内皮细胞功能及其调控机制的较理想的体外细胞培养模型.

abstractsObjective To research the response of endothelial cells to the fluid shear stress at the apex of an arterial bifurcation.Methods Using improved perfusion and T-shaped flow chamber,We controlled the force of the impact adjusted by the speed of peristaltic pump and flow control valve to establish a system for the culture of vascular endothelial cells,which may imitate the apex of an Arterial Bifurcation in vitro.The flow rates of either 250 ml/min [corresponding to a Reynolds number (Re) =125 based on inlet diameter] or 500 ml/min (Re =250) were used.Impact time was set up to 3 h,6 h,and 12 h.Inverted phase contrast microscope was used to observe the characteristics of the endothelial cell layer under the fluid shear stress.Results The cells surrounding the stagnation point still maintained polygonal under the flow rates of 250 ml/min and after 3,6,12 h.Cells exposed to fluid shear stress (WSS) and shear stress gradient (WSSG) area were elongated,aligned parallel to flow,and at lower density under the flow rates of 500 ml/min and after 12 h.The behavior was not blocked by cell proliferation inhibitor mitomycin C (MMC),indicating that cells migrated downstream from the stagnation point in response to impinging flow.Conclusion The T-shaped chamber can be used to imitate the environment of blood flow at the apex of an arterial bifurcation in vitro,and the device is also convenient and practical,which will be an ideal cell culture chamber to research the function of vascular endothelial cells under the fluid shear stress.