Itoh T, Chien S, Usami S
Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY.
Blood. 1995 Apr 15;85(8):2245-53.
To assess the role of intracellular hemoglobin concentration in the deformability of sickle (HbSS) cells after deoxygenation, rheologic coefficients (static rigidity E and dynamic rigidity eta) of density-fractionated individual sickle erythrocytes (SS cells) were determined as a function of oxygen tension (pO2) using the micropipette technique in a newly developed experimental chamber. With stepwise deoxygenation, E and eta values showed no significant increase before morphologic sickling but rose sharply after sickling. In denser cells, continued deoxygenation led to steep rises of E and eta toward infinity, as the cell behaved as a solid. The pO2 levels at which rheologic and morphologic changes occurred for individual SS cells during deoxygenation varied directly with the cell density. The extent of recovery in E and eta during reoxygenation varied inversely with the cell density. These results provide direct evidence that the intracellular sickle hemoglobin (HbS) concentration of SS cells plays an important role in their rheologic heterogeneity in deoxygenation and reoxygenation. The elevations of eta during pO2 alteration were greater than those of E, especially for the denser cells, suggesting the importance of the elevated dynamic rigidity in initiating microcirculatory disturbances in sickle cell disease.
为评估细胞内血红蛋白浓度在脱氧后镰状细胞（HbSS）变形性中的作用，使用微量移液器技术在新开发的实验室内，测定了密度分级的单个镰状红细胞（SS细胞）的流变学系数（静态刚性E和动态刚性η）随氧张力（pO2）的变化情况。随着逐步脱氧，在形态学上出现镰变之前，E和η值无显著增加，但在镰变后急剧上升。在密度较大的细胞中，持续脱氧导致E和η急剧上升直至无穷大，因为细胞表现得像固体一样。在脱氧过程中，单个SS细胞发生流变学和形态学变化时的pO2水平与细胞密度直接相关。复氧过程中E和η的恢复程度与细胞密度呈反比。这些结果提供了直接证据，表明SS细胞内镰状血红蛋白（HbS）浓度在其脱氧和复氧过程中的流变学异质性中起重要作用。在pO2改变过程中，η的升高大于E，尤其是对于密度较大的细胞，这表明动态刚性升高在引发镰状细胞病微循环障碍中的重要性。
