Carlson Brian E, Anderson Joseph C, Raymond Gary M, Dash Ranjan K, Bassingthwaighte James B
Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA.
Adv Exp Med Biol. 2008;614:353-60. doi: 10.1007/978-0-387-74911-2_39.
The binding and buffering of O2 and CO2 in the blood influence their exchange in lung and tissues and their transport through the circulation. To investigate the binding and buffering effects, a model of blood-tissue gas exchange is used. The model accounts for hemoglobin saturation, the simultaneous binding of O2, CO2, H+, 2,3-DPG to hemoglobin, and temperature effects. Invertible Hill-type saturation equations facilitate rapid calculation of respiratory gas redistribution among the plasma, red blood cell and tissue that occur along the concentration gradients in the lung and in the capillary-tissue exchange regions. These equations are well-suited to analysis of transients in tissue metabolism and partial pressures of inhaled gas. The modeling illustrates that because red blood cell velocities in the flowing blood are higher than plasma velocities after a transient there can be prolonged differences between RBC and plasma oxygen partial pressures. The blood-tissue gas exchange model has been incorporated into a higher level model of the circulatory system plus pulmonary mechanics and gas exchange using the RBC and plasma equations to account for pH and CO2 buffering in the blood.
血液中氧气和二氧化碳的结合与缓冲作用会影响它们在肺和组织中的交换以及在循环系统中的运输。为了研究结合与缓冲效应，采用了一种血液-组织气体交换模型。该模型考虑了血红蛋白饱和度、氧气、二氧化碳、氢离子、2,3-二磷酸甘油酸与血红蛋白的同时结合以及温度效应。可逆的希尔型饱和度方程有助于快速计算沿着肺和毛细血管-组织交换区域的浓度梯度在血浆、红细胞和组织之间发生的呼吸气体再分布。这些方程非常适合分析组织代谢瞬变和吸入气体的分压。建模表明，由于瞬变后流动血液中红细胞的速度高于血浆速度，红细胞和血浆氧分压之间可能会存在长期差异。血液-组织气体交换模型已被纳入一个更高层次的循环系统模型，该模型结合了肺力学和气体交换，使用红细胞和血浆方程来解释血液中的pH值和二氧化碳缓冲作用。
