Kim W S, Tarbell J M
Department of Chemical Engineering, Pennsylvania State University, University Park 16802.
J Biomech Eng. 1994 May;116(2):156-63. doi: 10.1115/1.2895714.
To determine the macromolecular transport properties of the tunica media of an artery wall deformed inhomogeneously by the transmural pressure, we combine a simple mechano-hydraulic model based on a two parameter strain-dependent permeability function, which was developed by Klanchar and Tarbell (1987), with a fiber matrix theory. The combined theory allows us to calculate the spatial distributions of porosity, solute partition, fiber radius and macromolecular solute concentration in the media and their dependence on the transmural pressure. The predictions from the combined theory are in good agreement with experimental measurements of sucrose space, albumin space and albumin concentration profiles in the media of rabbit aortas at transmural pressures of 70 and 180 mmHg. The predictions indicate that albumin transport through the aortic media is dominated by convection rather than diffusion. It is further demonstrated that the transport properties of unstressed planar tissue samples, which are often used in in vitro experiments, may be quite different from those of intact vessels in their natural cylindrical configuration because of variation in tissue deformation.
为了确定因跨壁压力而发生非均匀变形的动脉壁中膜的大分子传输特性，我们将基于由克兰查尔和塔尔贝尔（1987年）提出的双参数应变相关渗透率函数的简单机械液压模型与纤维基质理论相结合。该联合理论使我们能够计算中膜中孔隙率、溶质分配、纤维半径和大分子溶质浓度的空间分布及其对跨壁压力的依赖性。联合理论的预测结果与兔主动脉中膜在70和180 mmHg跨壁压力下蔗糖空间、白蛋白空间和白蛋白浓度分布的实验测量结果高度吻合。预测结果表明，白蛋白通过主动脉中膜的传输以对流为主而非扩散。进一步证明，由于组织变形的差异，体外实验中常用的无应力平面组织样本的传输特性可能与天然圆柱形完整血管的传输特性有很大不同。
