Sutera S P, Gardner R A, Boylan C W, Carroll G L, Chang K C, Marvel J S, Kilo C, Gonen B, Williamson J R
Blood. 1985 Feb;65(2):275-82.
The present study was designed to further the characterization of age-related changes in the deformability of human erythrocytes. The top (approximately young) and bottom (approximately old) 10% fractions of density-separated red cells from ten normal donors were subjected to graded levels of shear stress in a rheoscope. Measurements were made of steady-state elongation (cells tank treading in a state of dynamic equilibrium) and the time course of shape recovery following abrupt cessation of shear. In parallel with the rheologic experiments, several physical and chemical properties were assayed to determine correlates of mechanical properties. These included mean cell volume, mean corpuscular hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane proteins, and membrane phospholipid and protein concentration. The microrheologic observations revealed that only about 90% of the old cells retained their capacity to tank tread. However, the tank-treading cells elongated less than their younger counterparts at corresponding levels of shear stress, thus demonstrating a reduced level of deformability. Further analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.
本研究旨在进一步表征人类红细胞变形能力的年龄相关变化。从十名正常供体的密度分离红细胞中，取顶部（约年轻）和底部（约年老）10%的部分，在流变仪中施加不同程度的剪切应力。测量了稳态伸长（细胞在动态平衡状态下的罐状行进）以及剪切突然停止后形状恢复的时间过程。与流变学实验并行，测定了几种物理和化学性质，以确定力学性质的相关因素。这些因素包括平均细胞体积、平均红细胞血红蛋白浓度、A1型血红蛋白、膜蛋白糖基化以及膜磷脂和蛋白质浓度。微观流变学观察表明，只有约90%的老年细胞保留了罐状行进的能力。然而，在相应的剪切应力水平下，进行罐状行进的老年细胞伸长程度小于年轻细胞，从而表明其变形能力降低。对数据的进一步分析表明，膜粘度和弹性模量的增加以及过量表面积的显著损失，导致老年细胞改变形状的能力受到限制。
