Arslan Nurullah, Isik Sevim, Uykan Ozge
Department of Genetics and Bioengineering, Fatih University, Istanbul, Turkey.
Acta Bioeng Biomech. 2010;12(4):3-9.
Coronary artery disease is still one of the most important reasons of the death in the world. The endothelium is the membrane of special cells which lines the interior surface of blood vessels forming an interface between circulating blood in the lumen and the rest of the vessel wall. Endothelial cells (ECs) line the entire circulatory system, from the heart to the smallest capillary. ECs dysfunction has been linked with atherosclerosis through their response to fluid forces. ECs change their morphology when exposed to mechanical stresses. The morphological responses include reorientation, elongation, and rearrangement of adhering molecules. Atherosclerotic lesions are formed in specific arterial regions, where low and oscillatory endothelial shear stress (ESS) occur. In this study, the effects of steady and disturbed flow over human umbilical vein endothelial cells (HUVECs) at different flow rates and periods were determined. Steady flow experiments were performed at flow rate of 1000 cm3/min for twenty four hours. Disturbed flow experiments simulating the flow in branching regions of arterial systems were carried out at flow rates of 250 cm3/min for five hours. The results obtained testified to the morphological changes easily observed. The directional alignment of the cells was determined in the steady flow experiments. Under disturbed flow conditions we observed not only the cell movement at the stagnation point but also the polygonal cell shape downstream the flow field.
冠状动脉疾病仍然是全球最重要的死亡原因之一。内皮是由特殊细胞构成的膜，它衬于血管内表面，在管腔内循环血液与血管壁其余部分之间形成一个界面。内皮细胞（ECs）衬于整个循环系统，从心脏到最小的毛细血管。内皮细胞功能障碍通过其对流体作用力的反应与动脉粥样硬化相关联。当暴露于机械应力时，内皮细胞会改变其形态。形态学反应包括黏附分子的重新定向、伸长和重排。动脉粥样硬化病变形成于特定的动脉区域，这些区域存在低且振荡的内皮剪切应力（ESS）。在本研究中，测定了不同流速和时间段下稳定流和紊乱流对人脐静脉内皮细胞（HUVECs）的影响。稳定流实验在流速为1000 cm³/min的条件下进行24小时。模拟动脉系统分支区域血流的紊乱流实验在流速为250 cm³/min的条件下进行5小时。所获得的结果证实了易于观察到的形态学变化。在稳定流实验中测定了细胞的定向排列。在紊乱流条件下，我们不仅观察到了驻点处的细胞移动，还观察到了流场下游的多边形细胞形状。
