title: Creep and stress relaxation of human red cell membrane.
abstract: In contrast to most mechanical properties of the red cell, experimental information on stress relaxation (SR) of the membrane skeleton is scarce. On the other hand, many postulates or assumptions as to the value of the characteristic time of SR [Formula: see text] can be found in the literature. Here, an experiment is presented that allows measurement of [Formula: see text] up to values of about 10 h. The membrane skeleton was deformed passively by changing the spontaneous curvature of the bilayer thus transforming the natively biconcave red cells into echinocytes. This shape and the concomitant deformation of the skeleton were kept up to 4 h by incubation at 37 ℃. During this period, no plastic deformation (creep) was observed. After the incubation, the spontaneous curvature was returned to normal. The resulting shape was smooth showing no remnants of the echinocytic shape. Both observations indicate [Formula: see text] 10 h. This result is in gross disagreement to postulates or assumptions existing in the literature.
authors: Department of Physiology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany. thmfischer@gmail.com.|Laboratory for Red Cell Rheology, Krummer Weg 20, 52134, Herzogenrath, Germany. thmfischer@gmail.com.
authors: Thomas M
authors: TM
authors: Fischer
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology*; D004910:Erythrocyte Membrane / Q000502:physiology*; D006801:Humans; D013314:Stress, Mechanical
keywords: Characteristic time of creep; Characteristic time of stress relaxation; Echinocyte; Membrane skeleton; Plastic behavior