The role of human red blood cell membrane skeletal proteins in repetitive membrane strain and rupture.

The influence of the membrane skeleton on cell membrane deformability, elasticity, and rupture after repetitive cycles of membrane strain, release and rupture was investigated. Human red blood cells were electrofused to doublets, which showed the post-fusion oscillation-movement. Geometrical developments of heat-treated cells were measured and compared to control cells. Alterations of cluster length and fusion zone diameter during repetitive colloidosmotic swelling period grow with heat treatment, and the number of precedent swell phases has minor influence on these values. Irrespective of the treatment, the geometrical doublet configuration at which a membrane rupture is initiated has an almost constant roundness index of 0.89. Increasing heat treatment temperature was shown to affect both deformability and elasticity of the membrane, such that doublets start each swell phase of the oscillation cycle from decreased roundness values. Evidence is given that there is a difference in the mechanical properties between the membrane at the fusion zone and the membrane of native red blood cells.