FORCE RELAXATION AND PERMANENT DEFORMATION OF ERYTHROCYTE-MEMBRANE
FORCE RELAXATION AND PERMANENT DEFORMATION OF ERYTHROCYTE-MEMBRANE
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DOI：
10.1016/s0006-3495(83)84372-0
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发表时间：
1983-01-01
影响因子：
3.4
通讯作者：
HOCHMUTH, RM
中科院分区：
文献类型：
--
作者：
MARKLE, DR;EVANS, EA;HOCHMUTH, RM
用两种方法研究了红细胞膜的力松弛和永久变形过程：微管吸入部分松弛细胞和在两个微管之间延伸整个细胞。在这两个实验中，在表面拉伸比为3：1时，当拉伸时间小于几分钟时，残余膜变形的程度可以忽略不计。保持较长时间的拉伸会导致显著的力松弛和永久变形。永久变形的大小与总的伸展时间和外力的大小成正比。在此基础上，提出了一种表面变形的非线性本构关系，即将超弹性膜组件串联耦合到线性粘性过程中。与粘弹性固体的快速伸展或屈服以上的材料塑性流动中发生的作为热量的粘性耗散相比，这种粘性过程代表了通过结构膜组件的松弛而永久的分子重组所产生的耗散。来自这些实验的数据确定力松弛的特征时间常数，即表面粘度的比率。到弹性剪切模数，MU。因为细胞悬浮液中的白蛋白浓度强烈地介导力松弛的速率，所以。在以克为单位的白蛋白浓度为0.0%、0.01%、0.1%和1%时，分别测量10.1min、40.0min、62.8min和120.7分钟。表面粘度E是根据T的乘积计算的。和.MU..对于白蛋白浓度为0.0%、0.01%、0.1和1%的白蛋白，以克为单位。分别等于3.6Dyn S/cm、14.8dyn S/cm、25.6 dyn S/cm和51.9dyn S/cm。
Force relaxation and permanent deformation processes in erythrocyte membrane were investigated with 2 techniques: miropipette aspiration of a portion of a flaccid cell and extension of a whole cell between 2 micropipettes. In both experiments, at surface extension ratios < 3:1, the extent of residual membrane deformation is negligible when the time of extension is less than several minutes. Extensions maintained longer result in significant force relaxation and permanent deformation. The magnitude of the permanent deformation is proportional to the total time period of extension and the level of the applied force. Based on these observations, a nonlinear constitutive relation for surface deformation is postulated that serially couples a hyperelastic membrane component to a linear viscous process. In contrast with the viscous dissipation of energy as heat that occurs in rapid extension of a viscoelastic solid, or in plastic flow of a material above yield, the viscous process in this case represents dissipation produced by permanent molecular reorganization through relaxation of structural membrane components. Data from these experiments determine a characteristic time constant for force relaxation, .tau., which is the ratio of a surface viscosity, .eta. to the elastic shear modulus, .mu.. Because the concentration of albumin in the cell suspension strongly mediates the rate of force relaxation, values for .tau. of 10.1, 40.0, 62.8, and 120.7 min are measured at albumin concentrations of 0.0, 0.01, 0.1, and 1% by wt in grams, respectively. The surface viscosity, .eta., is calculated from the product of .tau. and .mu.. For albumin concentrations of 0.0, 0.01, 0.1, and 1% by wt in grams, .eta. is equal to 3.6, 14.8, 25.6 and 51.9 dyn s/cm, respectively.