Department of Thoracic and Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu 610041, China.
Comput Math Methods Med. 2012;2012:135256. doi: 10.1155/2012/135256. Epub 2012 Mar 7.
Previous research has observed concentration polarization in LDL and HDL in the arterial system. However, there is no report that links this concentration polarization to the development of vascular atherosclerosis (AS). Therefore, the purpose of this study is to establish the relationship between concentration difference of LDL and HDL and shear stress using a carotid bifurcation vascular model. PTFE was employed to create the carotid bifurcation model. Endothelial cells were coated on the inner wall of the graft. In a recirculation system, HDL and LDL concentration were measured under two different ICA flow velocities at 5 different locations within our model. We report the following: (1) LDL and HDL concentration difference was observed in both high flow and low flow environments; (2) the degree of LDL and HDL concentration polarization varied depending of high flow and low flow environment; (3) absolute values of concentration difference between LDL and HDL at the inner wall surface decreased with the increase in shear stress when shear stress was more than 1.5 Pa. This variation trend would be more pronounced if shear stress were less than 0.5 Pa. Our study suggests that under the action of shear stress, concentration differences of LDL or HDL create a disturbance in the balance of atherogenic factors and anti-As factors, resulting in the occurrence of AS.
先前的研究已经观察到在动脉系统中 LDL 和 HDL 的浓度极化现象。然而，目前还没有报道将这种浓度极化与血管粥样硬化（AS）的发展联系起来。因此，本研究旨在建立使用颈动脉分叉血管模型的 LDL 和 HDL 浓度差异与剪切力之间的关系。使用 PTFE 制作颈动脉分叉模型。将内皮细胞涂覆在移植物的内壁上。在再循环系统中，在我们的模型内的 5 个不同位置，在两种不同的 ICA 流速下测量 HDL 和 LDL 的浓度。我们报告如下：（1）在高流量和低流量环境中均观察到 LDL 和 HDL 的浓度差异；（2）LDL 和 HDL 浓度极化的程度取决于高流量和低流量环境；（3）当剪切力大于 1.5Pa 时，LDL 和 HDL 在壁面处的浓度差绝对值随剪切力的增加而减小。如果剪切力小于 0.5Pa，则这种变化趋势会更加明显。我们的研究表明，在剪切力的作用下，LDL 或 HDL 的浓度差异会破坏致动脉粥样硬化因素和抗 AS 因素之间的平衡，从而导致 AS 的发生。
