Amphiphile induced echinocyte-spheroechinocyte transformation of red blood cell shape


A possible physical explanation of the echinocyte-spheroechinocyte red blood cell (RBC) shape transformation induced by the intercalation of amphiphilic molecules into the outer layer of the RBC plasma membrane bilayer is given. The stable RBC shape is determined by the minimization of the membrane elastic energy, consisting of the bilayer bending energy, the bilayer relative stretching energy and the skeleton shear elastic energy. It is shown that for a given relative cell volume the calculated number of echinocyte spicula increases while their size decreases as the number of the intercalated amphiphilic molecules in the outer layer of the cell membrane bilayer is increased, which is in agreement with experimental observations. Further, it is shown that the equilibrium difference between the outer and the inner membrane leaflet areas of the stable RBC shapes increases if the amount of the intercalated amphiphiles is increased, thereby verifying theoretically the original bilayer couple hypothesis of Sheetz and Singer (1974) and Evans (1974).

This is a preview of subscription content, access via your institution.

Author information



Additional information

Received: 22 August 1997 / Revised version: 25 November 1997 / Accepted: 11 February 1998

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Iglič, A., Kralj-Iglič, V. & Hägerstrand, H. Amphiphile induced echinocyte-spheroechinocyte transformation of red blood cell shape. Eur Biophys J 27, 335–339 (1998).

Download citation

  • Key words Red blood cell
  • Spheroechinocyte
  • Membrane skeleton
  • Cell shape
  • Elastic energy