跨血管壁的水的定常运动及其对大分子传质的影响

STEADY STATE MOVEMENT OF WATER THROUGHARTERIAL WALL AND ITS EFFECT ONTRANSPORT OF MACROMOLECULES

本文对Tzeghai关于水,溶质和大分子跨血管壁的渗透模型进行了改进。主要的改进是:(1)既考虑内皮细胞间隙流动也考虑小的亲水孔的过滤。(2)将血管分为内膜和介质两层,而不是完全均匀的薄板。(3)考虑动脉壁的非各向同性对流和扩散效应。 基于这一模型得到的主要结果是紧接内皮下面存在一个射流相互作用区。在这个区域,沿垂直于管壁方向,压力和浓度并非线性下降,而是先上升,直到内膜某处达到最大值,然后才下降,特别是对于1.333×10~5Pa或更高的跨壁压力差,浓度最大值在内膜—介质交界附近,这正是动脉硬化斑块常发生的位置。

<ABSTRACT> In this paper the model by Tzeghai for vascular permeability to water, solules and macromolecules is improved. The main improvements include: l. both the flow in the intercellular clefts and the filtration through sma- ll hydrophilic pores are taken into consideration; 2. the arterial wall is divided into two layers (intima and media ) , instead of being taken as an uniform slab ; 3. the anisotropic convection and diffusion in the underl- ying tissue are considered. Our improved model shows that there exists a subendothelial interac- tion layer between the jets. As a result. the pressure of water and the con- centration of macromolecules in this layer do not decrease linearly. Inst- ead, the pressure and concentration increase first until the maximum is reached somewhere in the intima, and then they decrease monotonously. Especially when the transmural pressure is 1 .3 ×104Pa or above, the maxi- mum value of concentration is reached near the inferface of intima--media, the location where a therosclerosis usually occurs.