Effect of endothelial injury and increased blood pressure on albumin accumulation in the arterial wall: a numerical study.
Effect of endothelial injury and increased blood pressure on albumin accumulation in the arterial wall: a numerical study.
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DOI：
10.1016/s0021-9290(99)00226-2
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发表时间：
2000-06
影响因子：
2.4
通讯作者：
G. Karner;K. Perktold
中科院分区：
文献类型：
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作者：
G. Karner;K. Perktold
本研究探讨血管内皮细胞损伤和血压对白蛋白在动脉壁内积聚的影响。为此，建立了动脉管腔和动脉壁各层的耦合传质过程的数值模型。该模型考虑了直轴对称动脉段的内皮、内膜、内弹力层和中层的输运。在动脉腔充分发育的情况下，假设血液流动是稳定的，根据达西定律计算了壁层的过滤速度。管腔传质采用定常对流-扩散方程描述，多孔内膜和介质中的传质采用体积平均定常对流-扩散-反应方程模拟。管腔、内膜和中膜的转运过程由跨内皮细胞和IEL的流量耦合，用Kedem-Katchalsky方程进行数学描述。输运方程的数值解采用有限元方法。结果表明，健康的血管内皮细胞对血液和动脉壁之间的大分子交换具有很高的抵抗力。损伤的内皮细胞的阻力降低会导致进入壁内的质量流量增加，从而导致壁内浓度更高。对于健康的内皮细胞和受损的内皮细胞，血压对壁浓度水平的影响是不同的。对于健康的内皮，血压升高会导致内膜浓度的降低和中膜浓度的增加，而在内皮受损的情况下，血压的升高会导致内膜和中膜浓度的升高。
The present study investigates the influence of endothelial damage and of blood pressure on albumin accumulation in the arterial wall. For this purpose a numerical model for the coupled mass transport processes in the arterial lumen and in the various layers of the arterial wall is developed. The model considers the transport in the endothelium, intima, internal elastic lamina (IEL) and media of a straight axisymmetric arterial segment. In the arterial lumen fully developed stationary blood flow is assumed, the filtration velocity in the wall layers is calculated applying Darcy's law. The description of the luminal mass transport uses the stationary convection–diffusion equation, the transport in the porous intima and media is modelled applying the volume-averaged stationary convection–diffusion–reaction equation. The transport processes in the lumen, intima and media are coupled by the flux across the endothelium and IEL, which is mathematically described using the Kedem–Katchalsky equations. The numerical solution of the transport equations applies the finite element method. The results demonstrate a high resistance of the healthy endothelium to macromolecule exchange between blood and the artery wall. The reduced resistance of an injured endothelium causes an increased mass flux into the wall which results in higher concentration levels within the wall. The effect of the blood pressure on the wall concentration level is different for a helathy and an injured endothelium. In the case of a healthy endothelium a blood pressure increase causes a decrease of the intimal concentration and an increase of the medial concentration, whereas in the case of an injured endothelium an increased blood pressure results in higher concentration levels within the intima and media.