红细胞变形的动力学行为

DYNAMIC BEHAVIORS OF EKTACYTOMETRIC DEFORMATION INDEX OF ERYTHROCYTES IN DIFFERENT BUFFERS

用激光衍射仪测量了兔红细胞在PBS和PVP两种介质里的应力松弛过程.结果表明,红细胞在低粘介质(PBS)中的动力学行为和它在高粘介质(PVP)中的动力学响应有显著差异,除了等容变形和非等容变形以外,还有一个从定向到随机取向的变化过程.故在低粘介质中测得的红细胞应力松弛过程中变形指数(DI)随时间(t)的变化是由红细胞变形(DI)d和红细胞取向(DI)or两部分构成的.红细胞变形的特征时间(约10毫秒)比取向过程的特征时间(约50秒)小2～3个量级.这就使得我们有可能从测得的DI—t曲线中把(DI)d和(DI)or区分开来,从而获得关于红细胞动力学特性的更多的信息.这一点,在临床实践是很有意义的.

Using ektacytometric, we obtained relaxation curves of rabbit's erythrocytes suspended in PBS and PVP respectively. Typical results are shown in fig.1. They could be fitted by experience formulas as follows:For PVP: Dl( t) =and for PBS.where (Dl)0 is the initial value of DI, t0, t1 and t2 are characteristic time of non-isochoric deformation, isochoric deformation and orientation of erythrocyte respectively. And α1, α2, β are time constant corresponding to to, (t1-t0) and t1 . Our experimental results show that:1. The deformation characteristic time of erythrocyte is in order of 10-1 sec, while the orientation characteristic time of erythrocyte is in order of 50 sec. The later is about several hundred times of the former. This feature provide a criteria to distinguish the contribution of orientation to measured Dl from that of deformation. Based on this feature a new way to measuring the rheological properties of erythrocyte more reasonably is developed.2. Form the point of view of dynamic behaviors of erythrocyte, the suspending medium with low viscosity (such as PBS) seems to be better than those medium with high viscosity (such as PVP) . The former would be more sensitive than the later.Acknowledgement: This research was supported by the National Science Foundation of China