AN EASY-TO-USE MODEL FOR O-2 SUPPLY TO RED MUSCLE - VALIDITY OF ASSUMPTIONS, SENSITIVITY TO ERRORS IN DATA
AN EASY-TO-USE MODEL FOR O-2 SUPPLY TO RED MUSCLE - VALIDITY OF ASSUMPTIONS, SENSITIVITY TO ERRORS IN DATA
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DOI：
10.1016/s0006-3495(95)80300-0
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发表时间：
1995-04-01
影响因子：
3.4
通讯作者：
GROEBE, K
中科院分区：
文献类型：
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作者：
GROEBE, K
提出了一个简单易用的肌肉供氧毛细管柱体模型，该模型考虑了对实际结果最重要的所有因素：(1)红细胞(RBC)沿毛细血管卸载O-2，(2)血液颗粒性质的影响，(3)红细胞内自由和血红蛋白促进的O-2扩散和反应动力学，(4)肌肉细胞内自由和肌红蛋白促进的O-2扩散，以及(5)分隔红细胞和组织的无载体区域。在第一种方法中，采用了一种高度简化但相当准确的方法来处理毛细血管内及其附近的复杂三维氧气扩散场。作为另一种选择，包括了使用红细胞/毛细血管扩散能力的更现实的描述，模型开发逐步进行，并被设计为便于广大读者理解。尽管考虑了许多特征，但该模型应用起来很简单，即使对于不是建模领域专业的科学家也是如此。由该模型计算的P-O2分布与实验数据和以前的模型结果具有很好的定性一致性。通过对所开发的模型进行适当的扩展，表明对于较大范围的肌肉性能，相当普遍地可以安全地忽略以下并发症。(1)毛细血管附近氧气扩散场的复杂性；(2)毛细管区截面偏离圆形；(3)平行于毛细管方向的氧气扩散；(4)氧气消耗速率与P-O2的依赖关系。最后，进行了敏感性分析，其中研究了输入数据中的误差向结果中的传播。对计算出的灵敏度的解释给出了肌肉氧供应对各种输入参数的具体依赖关系的见解。此外，控制载体促进的氧气向肌肉扩散的基本相互关系变得明显，并进行了讨论。
An easy-to-use capillary cylinder model of O-2 supply to muscle is presented that considers all those factors that are known to be most important for realistic results: (1) red blood cell (RBC) O-2 unloading along the capillary, (2) effects of the particulate nature of blood, (3) free and hemoglobin-facilitated O-2 diffusion and reaction kinetics inside RBCs, (4) free and myoglobin-facilitated O-2 diffusion inside the muscle cell, and (5) carrier-free region separating RBC and tissue. In a first approach, a highly simplified yet reasonably accurate treatment of the complex three-dimensional oxygen diffusion field in and next to capillaries is employed. As an alternative, a more realistic description using RBC/capillary diffusing capacity has been included, Model development proceeds step by step and is designed to be easily comprehensible for a broad readership. In spite of the number of features accounted for, the model is simple to apply, even for scientists not specialized in the field of modeling. P-O2 distributions calculated by the model are in good qualitative agreement with experimental data and with former modelling results, By means of suitable extensions to the model that are also developed it is shown for a wide range of muscle performances that quite generally the following complication may be neglected safely. (1) complexity of O-2 diffusion field near capillaries, (2) deviations of capillary domain cross sections from the circular shape, (3) O-2 diffusion parallel to the capillary direction, and (4) P-O2 dependence of O-2 consumption rate. Finally, a sensitivity analysis is performed in which propagation of errors in the input data into the results is investigated. The interpretation of the calculated sensitivities gives insights in the specific dependencies of muscular O-2 supply on the various input parameters. Moreover, basic interrelations governing carrier-facilitated diffusional O-2 transport to muscle become apparent and are discussed.