The kinetics of O2 release by human red blood cells in the presence of external sodium dithionite.
The kinetics of O2 release by human red blood cells in the presence of external sodium dithionite.
复制标题
DOI：
10.1016/s0021-9258(18)90790-8
复制
发表时间：
1984-10
期刊：
影响因子：
--
通讯作者：
K. Vandegriff;J. Olson
中科院分区：
文献类型：
--
作者：
K. Vandegriff;J. Olson
用停流快速混合技术检测了人红细胞在外加二亚硫酸钠存在下的氧释放。使用先前开发的用于描述摄氧量的三维圆盘模型(Vanderriff，K.D.和Olson，J.S.(1984)BiPhys)对所得到的时间进程进行定量分析。J.45,825-835)。该方案考虑了氧气通过外部未搅拌的溶剂层的扩散，以及细胞内的氧气扩散和与血红蛋白的化学反应。将这个模型应用到脱氧时间过程中需要考虑三个额外的因素：自由氧与外部亚硫酸钠的反应，协同氧与细胞内血红蛋白的结合，以及碱性玻尔效应。由此产生的理论处理既准确地描述了观察到的脱氧率与连二亚硫酸盐浓度和pH的关系，也准确地描述了相应的时间进程的确切形状。不需要膜对氧扩散的阻力来模拟先前提出的观测数据(Lawson，W.H.，Jr.，Holland，R.A.B.和Forster，R.E.(1965))。J.Appl.物理。20,912-918)。最终的三维模型是通用的，并首次允许分析氧气摄取和释放动力学(Vandes riff，K.D.和Olson，J.S.(1984)J.Biol)。化学。259、12619-12627)。
Oxygen release by human erythrocytes in the presence of external sodium dithionite was examined by stopped-flow, rapid mixing techniques. The resultant time courses were analyzed quantitatively using a three-dimensional disc model which had been developed previously to describe oxygen uptake (Vandegriff, K. D., and Olson, J. S. (1984) Biophys. J. 45, 825-835). This scheme takes into account diffusion of oxygen through external unstirred solvent layers and intracellular oxygen diffusion and chemical reaction with hemoglobin. Application of this model to deoxygenation time courses required three additional considerations: the reaction of free oxygen with external sodium dithionite, cooperative oxygen binding to intracellular hemoglobin, and the alkaline Bohr effect. The resultant theoretical treatment described accurately both the observed dependence of the deoxygenation rate on dithionite concentration and pH and the exact shapes of the corresponding time courses. Membrane resistance to oxygen diffusion was not required to simulate the observed data as had been suggested previously (Lawson, W. H., Jr., Holland, R. A. B., and Forster, R. E. (1965). J. Appl. Physiol. 20, 912-918). The final, three-dimensional model is general and allows, for the first time, analysis of both oxygen uptake and release kinetics (Vandegriff, K. D., and Olson, J. S. (1984) J. Biol. Chem. 259, 12619-12627).