Affiliations: Department of Medical Physics, Beijing Medical University, Beijing 100083, China | Department of Mechanics and Engineering Science, Peking University, Beijing 100871, China | The 3rd Hospital Affiliated to Beijing Medical University, Beijing 100083, China | The Experiment Center, Beijing Medical University, Beijing 100083, China
Note: [] Correspondence should be addressed to: Prof. Zong‐yao Wen, Department of Medical Physics, Beijing Medical University, Beijing 100083, China. E‐mail: rheol@mail.bjmu.edu.cn.
Abstract: With a new ektacytometry, we studied the relation between the microstructure of red blood cell (RBC) membrane and the rheological properties of RBCs in a shear flow field of low viscosity. The main contributions of this paper are as follows: 1. The hemorheological meanings of the orientation index (DI)_{\rm or} and the small deformation index (DI)_{\rm d} were explored. (DI)_{\rm or} is an overall rheological index depending on the deformability and morphology of RBCs. The better the physiological shape of RBCs is maintained, the greater the (DI)_{\rm or} is. (DI)_{\rm d} can be used to describe the lipid fluidity of RBC membrane. Such an explanation for the meaning of (DI)_{\rm d} has been forcefully supported by our experiments using electron spin resonance (ESR) and fluorescence polarization. 2. The influence of wheat germ agglutinin (WGA) of different concentrations on the lipid fluidity of membrane is different from that of concanavalin A (ConA). The lipid fluidity of membrane changes with WGA concentration treating RBCs and there is a maximum value for the membrane fluidity at a specific concentration of WGA. However, the deformability of membrane described by the integrate deformation index (IDI) monotonically decreased with the increase in WGA concentration treating RBCs. 3. It is concluded that the increase in the lipid fluidity of red cell membrane is not necessarily associated with the improvement of RBC deformability.
Keywords: New ektacytometry, lipid fluidity, deformability, red blood cell, membrane, hemorheology
