Changes in shape and osmotic resistance of human erythrocytes resulted from changes in the lysolecithin content of the membranes.

Abstract

Incubation of human erythrocytes in lysolecithin-containing medium, prepared by an addition of purified lysolecithin to blood plasma or to phosphate-buffered saline, induced the increases in lysolecithin content of the erythrocyte membranes as well as morphological changes of the cells from normal biconcave disc to crenated or spherical forms. The erythrocytes with slight excess of lysolecithin incorporated, which take shapes of crenated disc or crenated sphere, rather have increased osmotic resistance, whereas those with much more lysolecithin, taking almost spherical form, show reduced osmotic resistance. After washing these erythrocytes with heated normal plasma to remove excess lysolecithin from the membrane, the increased osmotic resistance observed in the former erythrocyte preparation was restored to the normal level, whereas the decreased resistance in the latter cell preparation was never reversed, in spite of the restoration to the normal morphological shape.