The rate of oxygen uptake by human red blood cells.
The rate of oxygen uptake by human red blood cells.
复制标题
人体红细胞吸收氧气的速率。
DOI：
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发表时间：
1979
影响因子：
4.8
通讯作者：
J. Olson
中科院分区：
文献类型：
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作者：
J. Coin;J. Olson
采用双波长停止流动技术测量完整和重组的人红细胞的摄氧量。人体红细胞的吸氧速率大约是与游离血红蛋白相对应的氧结合速率的40倍（在0.125 mM O2, 25℃时，t 1/2等于80 ms）。通过红细胞细胞质的氧运输是这一差异的部分原因，并预测摄取的一半时间约为15毫秒，这仍然比实验观察到的时间小5倍。进一步限制吸收似乎是由于存在未搅拌的溶剂层邻近红细胞表面。混合后，这些层很快形成，并由于细胞的吸收而耗尽氧气。这要求大部分氧分子必须扩散相当大的距离，1.0到5.0微米，才能穿透红细胞。建立了一个数学模型，以考虑在厚度随时间增加的未搅拌溶剂层中的扩散。该方案既可以定量地解释表观吸收速率对O2浓度的依赖性，也可以定量地解释观察到的时间过程的形状。此外，为O2反应建立的扩散参数也可用于定量描述在二亚硫酸钠存在下细胞对CO和异氰酸乙酯的吸收速率和时间过程，以及细胞对O2的释放速率和时间过程。最后，用于描述停止流动结果的参数也可用于定量模拟从以前的红细胞薄膜研究中获得的氧气摄取时间过程(Sinha, a.k.（1969）博士论文，加州大学旧金山分校；Thews， G. (1959) Arch。对杂志。犯罪。（Pflufgers） 268, 308-317)。
Oxygen uptake into intact and reconstituted human red blood cells was measured using dual wavelength, stopped flow techniques. The rate of oxygen uptake by human erythrocytes is roughly 40 times slower (t 1/2 congruent to 80 ms at 0.125 mM O2, 25 degrees C) than the corresponding rate of oxygen combination with free hemoglobin. Oxygen transport through the red cell cytoplasm accounts for part of this difference and predicts a half-time of uptake of about 15 ms, which is still 5 times smaller than that observed experimentally. Further limitation of uptake appears to be due to the presence of unstirred layers of solvent adjacent to the red cell surface. Very rapidly after mixing, these layers form and become depleted of O2 due to uptake by the cells. This requires that the bulk of the oxygen molecules must diffuse over rather large distances, 1.0 to 5.0 micrometer, before they can penetrate the erythrocytes. A mathematical model was developed to take into account diffusion through an unstirred solvent layer which increases in thickness with time. This scheme can account quantitatively both for the dependence of the apparent rate of uptake on O2 concentration and for the shape of the observed time courses. In addition, the diffusion parameters which were developed for the O2 reaction can also be used to describe quantitatively the rates and time courses of CO and ethyl isocyanide uptake and the rates and time courses of O2 release from cells in the presence of sodium dithionite. Finally, the parameters used to describe the stopped flow results can also be used to simulate quantitatively O2 uptake time courses obtained from previous studies with thin films of red cells (Sinha, A. K. (1969) Ph.D. dissertation, University of California, San Francisco; Thews, G. (1959) Arch. Gesamte Physiol. Mens. Tiere (Pflufgers) 268, 308-317).