ANALYSIS OF SOLUTE AND WATER TRANSPORT IN THE KIDNEY

肾脏中溶质和水转运的分析

• 批准号: 3230153
• 负责人: JOHN L STEPHENSON
• 金额: $ 22.02万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-01-01 至 1988-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3230153
• 关键词: biological fluid transport; biological models; body fluid osmolarity; diuretics; electrolyte balance; excretion; hydrostatic pressure; ion transport; kidney circulation; mathematical model; membrane permeability; model design /development; nonblood rheology; radiotracer; renal medulla; renal tubular transport; renal tubule; scintillation cameras; sodium chloride; solute; urea; water flow

The specific aims of this project are: (1) To determine the relation of medullary concentration gradients and the osmolality of final urine in the mammalian kidney to tubular and vascular permeabilities, flows and architecture. (2) To develop a mathematical model of electrolyte transport in the whole kidney, which includes electrolytes (Na, K, Cl, HC03, H2P04, H), glucose, urea, protein oncotic forces, hydrostatic pressure, and electrical potential. (3) To identify unidirectional membrane permeabilities and regional blood flows from temporal and spatial patterns of radionuclide excretion as determined from CAT scans. The general methodology developed for the solution of non-electrolyte models of the whole kidney will be used to sovle the extended models. Namely, an initial estimate is made of the "global" variables of concentrations, hydrostatic pressure, and electrical potential in the cortical and medullary interstitium. The equations describing flow, concentration, pressure, electric potential, and transmureal fluxes of solutes and water along the tubules and capillaries are then solved, and conservation of mass and electric charge is tested. The estimates of the global variables are then iteratively improved by appropriate mathematical and computational methods until conservation is satisfied to some selected tolerance. This global solution strategy opens the network of interacting feedback loops in whole organ function and allows us to follow any selected variable as a function of any selected model parameter or boundary condition. The long term objective of the research is to develop models that relate normal and pathological renal function to underlying microscopic transport processes in the membranes and cells of the renal tubules and their associated vasculature. More specifically the project focuses on factors affecting the concentration and dilution of urine and sodium excretion in intact and isolated perfused (rat) kidney with the objective of understanding the control of body fluid osmolality and the regulation of extracellular fluid volume. It is relevant to every disease with a disturbance of either.

本课题的具体目标是：（1）确定 髓质浓度梯度和最终尿液的渗透压 哺乳动物肾脏对肾小管和血管的渗透性、流量和 架构 (2)建立电解质迁移的数学模型 在整个肾脏中，其包括电解质（Na，K，Cl，HCO3，H2PO4， H）、葡萄糖、尿素、蛋白质结合力、静水压力，以及 电势 (3)识别单向膜 渗透性和区域血液流动的时间和空间模式 放射性核素的排泄，如从CAT扫描确定的。 非电解质溶液的一般方法 扩展模型采用全肾模型。 也就是说，对“全局”变量进行初步估计， 浓度，静水压力和电势， 皮质和髓质的神经节。 描述流动的方程， 浓度、压力、电势和透膜通量 然后溶解沿着小管和毛细血管的溶质和水，并且 检验了质量和电荷守恒。 的估计 然后通过适当的数学方法迭代地改进全局变量 和计算方法，直到守恒满足一些选定的 宽容 这一全球解决方案战略打开了互动网络， 整个器官功能的反馈回路，使我们能够跟踪任何选择的 作为任何选定模型参数或边界的函数的变量 条件 这项研究的长期目标是建立与以下方面有关的模型： 正常和病理性肾功能与基础显微镜下转运 肾小管的膜和细胞中的突起及其 相关的脉管系统。 更具体地说，该项目侧重于 影响尿的浓度和稀释以及钠排泄， 完整和离体灌注（大鼠）肾脏，目的是 了解体液渗透压的控制和 细胞外液量 它与每一种疾病有关， 的干扰。