MEMBRANE MODEL OF ENDOTHELIAL-CELLS AND LEUKOCYTES - A PROPOSAL FOR THE ORIGIN OF A CORTICAL STRESS

Previous models of the erythrocyte membrane have been based on the ass umption that the resting curvature of the membrane is either flat or h as a small curvature relative to the overall cell dimension. In contra st, several recent experimental observations, both in leukocytes and i n endothelial cells, suggest that local regions of the membrane may ha ve high membrane curvature in the resting state. The resting curvature may be of the or-der of plasmalemmal vesicles in endothelial cells or surface membrane folds on leukocytes. A tension is required to unfold the membrane with strain energy which depends largely on mean curvatu re. It is proposed that the tendency of endothelial or leukocyte membr anes to wrinkle in the unstressed state may provide a restoring force, i.e. a cortical tension.