Xie S L, Reed R K, Bowen B D, Bert J L
Department of Chemical Engineering, University of British Columbia, Vancouver, Canada.
Microvasc Res. 1995 Mar;49(2):141-62. doi: 10.1006/mvre.1995.1012.
A compartmental model consisting of the circulation, a general interstitium, and the lymphatics, is formulated to describe the transport and distribution of fluid and plasma proteins (albumin) in the human microvascular exchange system. Transcapillary mass exchange is assumed to occur via a coupled Starling mechanism. Unknown or poorly quantified model parameters are estimated by statistical fitting of simulation predictions to five different sets of experimental data. The data consist of steady-state and transient plasma and interstitial volumes and colloid osmotic pressures measured under laboratory or clinical conditions for normal humans and for patients with nephrotic syndrome or mild heart disease. In all cases, it is assumed that the system response to perturbations imposed either artificially or through illness is due to changes in the Starling driving forces. The three best-fit parameters were found to be normal capillary hydrostatic pressure, Pc,o = 11.0 mm Hg; albumin reflection coefficient, sigma = 0.99; and lymph flow sensitivity, LS = 43.1 ml/mm Hg.hr. Three other parameters, which were unknown but related to the estimated parameters through steady-state mass balance equations, were determined to be fluid filtration coefficient, KF = 121.1 ml/mm Hg.hr; albumin permeability-surface area product, PS = 73.0 ml/hr; and normal lymph flow, JL,o = 75.7 ml/hr. The fully described model was validated by comparisons between (1) simulation predictions and data used in parameter estimation, (2) estimated transport parameters and available literature values, and (3) model predictions and an additional set of experimental data.
构建了一个由循环系统、一般间质和淋巴管组成的房室模型，以描述人体微血管交换系统中液体和血浆蛋白（白蛋白）的运输和分布。假设跨毛细血管的物质交换通过耦合的斯塔林机制发生。通过将模拟预测与五组不同的实验数据进行统计拟合，估计未知或量化不足的模型参数。这些数据包括在实验室或临床条件下，针对正常人和患有肾病综合征或轻度心脏病的患者测量的稳态和瞬态血浆及间质体积以及胶体渗透压。在所有情况下，都假设系统对人为施加或因疾病引起的扰动的反应是由于斯塔林驱动力的变化。发现三个最佳拟合参数分别为正常毛细血管静水压，Pc,o = 11.0 mmHg；白蛋白反射系数，sigma = 0.99；以及淋巴流敏感性，LS = 43.1 ml/mmHg·hr。另外三个参数，虽然未知，但通过稳态质量平衡方程与估计参数相关，确定为滤过系数，KF = 121.1 ml/mmHg·hr；白蛋白通透面积乘积，PS = 73.0 ml/hr；以及正常淋巴流，JL,o = 75.7 ml/hr。通过以下比较对完全描述的模型进行了验证：(1) 模拟预测与参数估计中使用的数据；(2) 估计的运输参数与现有文献值；以及(3) 模型预测与另一组实验数据。
