The dynamics of the stress stage of osmotic haemolysis.

A simple physical model for the dynamics of the stress stage of osmotic haemolysis is presented. An 'elastic restitutive coefficient' for the red cell membrane is defined to relate the increase of internal pressure to the volume change during the stress stage, and it is estimated on the basis of the work of Evans et al. (1976, 1977). It is shown that the time elapsed between complete swelling and the start of haemoglobin leakage can be a substantial part of the total haemolysis time, in accordance with experimental results reported in the literature.