RELATION BETWEEN ERYTHROCYTE DEFORMABILITY, CELL SHAPE, AND MEMBRANE SURFACE TENSION

Erythrocytes which have been transformed into spheres by the action of surface-active substances, such as bile or free fatty acids, are more rigid than normal red cells, as is shown by viscosity measurements and microscopic observation. The rheological differences between biconcave and sphered red cells are considered to depend upon the degree of membrane stretching, which is maximal in the normal red cell and lowered in the sphered erythrocyte. Because the stretching of the cell membrane is probably caused by a surface tension between plasma and cell surface, red-cell deformability depends, among other things, upon the composition of the plasma. © 1969 Springer-Verlag.