PERMSELECTIVITY OF MYOCARDIAL CAPILLARIES (EFFECTS OF ELECTROKINETICS)

一个理想化的连续模型的电动运输是 分析溶质和势垒电荷对 微血管通透性 糖萼纤维基质 经毛细血管交换屏障的内皮间裂是 用代表内皮细胞表面的平行板建模 和一个由相同圆柱体组成的桥接规则阵列， 糖萼纤维 为了计算内部的静电势 约束纤维矩阵，线性Poisson-Boltzmann方程为 求解单个有界柱和有界柱的规则阵列 使用几种分析方法（分离变量法、绿色法 函数和线性叠加以及单位单元近似）， 数值方法（边界元法的直接公式化， 边界配点法）。 势单调衰减， 离表面的距离在4到5德拜之间消失 长度 对于糖萼中血浆超滤液的典型值， 填充的内皮间裂，即德拜长度为8 A，板 分离120 A，柱半径6 A，表面电位60 mV，孔隙率值小于97%时电位保持非零。 因此，在这个理想化模型的整个受限基质区域中， 有增强的阴离子和减弱的阳离子对流输送 与中性分子相比。 这种影响对于 双层延伸到双层区域的较大分子 靠近电位值最大的柱或板。 这一结果与已发表的实验观察结果一致， 带电分子的运输。

An idealized continuum model of electrokinetic transport is developed to analyze the contributions of solute and barrier charge to microvascular permeability. The glycocalyx fiber-matrix-filled interendothelial cleft of the transcapillary exchange barrier is modelled with parallel plates representing endothelial cell surfaces and a bridging regular array of identical cylinders representing glycocalyx fibers. To calculate the electrostatic potential within the confined fiber-matrix, the linear Poisson-Boltzmann equation is solved for a single bounded post and a regular array of bounded posts using several analytical methods (separation of variables, Green's functions and linear superposition and unit cell approximations) and numerical methods (direct formulation of a boundary element method and boundary collocation method). The potential decays monotonically with distance from the surfaces vanishing between four and five Debye lengths. For values typical of plasma ultrafiltrate in a glycocalyx filled interendothelial cleft, namely a Debye length of 8 A , plate separation of 120 A, post radius of 6 A and surface potential of 60 mV, the potential remains nonzero for porosity values less than 97%. Thus, throughout the confined matrix region of this idealized model, there is enhanced anionic and diminished cationic convective transport compared to neutral molecules. The effect is more pronounced for larger molecules whose double layers extend into double layer regions close to the post or plates where the potential magnitude is greatest. This result agrees with published experimental observations of transport of charged molecules.