Varadharajan M, Jayaraman G
Biomechanics Division, Indian Institute of Technology, New Delhi.
IMA J Math Appl Med Biol. 1994;11(3):193-205. doi: 10.1093/imammb/11.3.193.
A theoretical approach to study the uptake of sodium ions across the gastrointestinal mucosa and the concentrations at which they are taken up into the underlying blood capillaries has been attempted. A two-phase model of the mucosa is considered, consisting of an extracellular phase and a cellular phase. The model takes into account two important modes of transport: diffusion under concentration gradient and potential gradient (electrodiffusion) and active transport which is ATPase enzyme mediated. Appropriate partial differential equations for the two mechanisms of transport are derived and are solved by iterative methods. An approximate distance from the lumen where the capillaries lie is somewhere between 10 and 15% of the total wall length. The mean concentration of sodium ions made available for absorption at the capillaries is studied with time. A functional form for the variation of potential with respect to distance is proposed, and by comparing model solutions with experimental data it is calculated explicitly.
已尝试采用一种理论方法来研究钠离子跨胃肠黏膜的摄取以及它们被摄取到下层毛细血管中的浓度。考虑了黏膜的两相模型，该模型由细胞外相和细胞相组成。该模型考虑了两种重要的运输方式：在浓度梯度和电位梯度下的扩散（电扩散）以及由ATP酶介导的主动运输。推导了两种运输机制的适当偏微分方程，并通过迭代方法求解。毛细血管所在位置距管腔的近似距离约为总壁长的10%至15%。研究了随时间变化的可用于在毛细血管处吸收的钠离子平均浓度。提出了电位随距离变化的函数形式，并通过将模型解与实验数据进行比较来明确计算。
