Echinocyte-stomatocyte transformation and shape control of human red blood cells: morphological aspects

Red cell morphology was studied after the induction of echinocytic transformation by metabolic depletion, Ca2+ loading, and salicylate and stomatocytic transformation with chlorpromazine. The results indicate that the red cell has an energy-dependent shape control mechanism that allows it to counteract shape-changing stimuli such as metabolic depletion. Albumin was found to induce stomatocytic transformation, whereas gamma-globulins induced echinocytic transformation. Loading of the red cell with calcium resulted in polymorphous membrane damages such as submembranous, "blister-like" lesions, and membrane disintegration; the red cell age had no influence on this process. Conversely, the stomatocyte-echinocyte transformation induced by chlorpromazine and salicylate was shifted towards echinocytes in density-separated old red cells. Sphero-stomatocytes were capable of echinocytic transformation with spicule formation within the red cell vacuoles, whereas sphero-echinocytes were unable to undergo stomatocytic transformation without hemolysis. These observations may help to unravel the complexity of echinocyte-stomatocyte transformation of red blood cells.