TRANSIENT INCREASE IN DEFORMABILITY OF STRESSED RED-BLOOD-CELLS AND ROLE OF PLASMA-PROTEINS

In the context of possible fatigue and eventual destruction of red blood cells (RBCs) in the circulation, changes in deformability (filterability) were studied in RBCs which had just undergone deformation. Fresh human RBCs suspended in media of varying protein concentrations were stressed by causing them to pass through a 5-mu-m Nuclepore filter. Resultant changes in their deformability were assessed from their mean pore passage time in a subsequent filter passage. Contrary to the expectation, that deformability would be reduced, shortened passage times were observed for those stressed RBCs. The changes were, however, transient and, like the initial passage times, were an increasing function of the protein concentration in the suspending fluid. These results appeared to be consistently explicable by assuming release due to stresses and readsorption in time for plasma protein molecules normally adsorbed on cell surfaces. An analysis, furthermore, yielded acceptable estimates for magnitude of the cell-plasma protein interaction, number of protein molecules normally adsorbed on a cell, and also cell membrane viscosity and its apparent change due to the protein adsorption.