Vesicle production of heated and stressed erythrocytes

Human erythrocytes develop vesicles by budding when heated to temperatures close to the thermal transition for spectrin. Regularly spaced strings of vesicles also develop if cells heated to 51--54 degrees C are pulled into unstable shapes by flow of liquid between cover slips. These strings of vesicles develop when cells which had attached to the glass are restrained in the flow by a long membrane-bound tether which maintains a connection with the attachment site on the glass. Breakup into regularly spaced vesicles suggests the breakup of a liquid-like cylinder by growth of Rayleigh instabilities. The ratio of length:diameter of the fragments of cylinder on which each disturbance grew ranged from 2.2 to 5.4 to 1 with a peak of 3.2, as measured from scanning electron micrographs. The upper limit of the range is slightly less than the ratio for the disturbance most likely to grow if surface tension and viscosity alone controlled the vesicle formation. Similar vesicle formation when the form-maintaining structures were weakened has been reported in other systems.