带糖萼层的大分子跨动脉壁传质模型研究

目的 通过研究复杂血管内的糖萼层、高血压等因素对大分子跨血管壁传输的影响,为进一步认识动脉粥样硬化的成因提供了理论依据。方法 考虑动脉壁的生理结构：内皮、内膜、内膜弹性层、中膜和糖萼层,建立了动脉壁中大分子跨壁传质的5层多孔介质模型。假设动脉为一段轴对称长直圆管,血浆为牛顿流体,用解析法得到稳态流动下的动脉壁内血浆渗流速度和大分子浓度分布。结果 糖萼层的厚度对血浆渗流速度的影响几乎可以忽略。糖萼层的厚度越大,对大分子传质的阻碍作用越明显。糖萼层的存在降低了高血压对大分子传质的影响。结论 糖萼层对大分子跨壁传质有很大的阻碍作用,即使在高血压情况下,内膜层大分子浓度的增幅也非常小。因此,糖萼层的存在能有效降低因高血压引起的大分子跨血管过度传输。

Effect of the endothelial glycocalyx layer on macromolecular transport in the arterial wall

Objective This paper investigates the effects of the endothelial glycocalyx layer （EGL） and hypertension on macromolecular transport in the arterial walls to provide a theoretical method to understand the occurence of atherosclerosis.Methods We estabilish a five-layer porous media model to simulate macromolecular transport.The artery is assumed to be an axisymmetric circular tube and plasma is Newtonian fluid.Theoretical analysis is used to obtain filtration velocity and macromolecular concentration under steadystate flow condition.Results The effect of EGL＇ s thickness on filtration velocity can be neglected.With the increase of EGL＇ s thickness,the resistance of macromolecular transport becomes more obvious.The existence of EGL decreases the effect of the hypertension on macromolecular transport.Conclusions EGL offers rather high resistance to macromolecular permeation.Even under hypertension condition,the increase of macromolecular concentration within the intima is not obvious.In the presence of EGL,the excessive macromolecule penetration into the arterial walls caused by hypertension can be prevented effectively.