Effect of cell shape on extravascular hemolysis.

Although it has been inferred that alteration of erythrocyte shape causes cell clearance. no direct measure of the effect of varying shape on clearance has been made. In this study, the protein oxidant, diamide, was employed to fix rat erythrocytes in altered shapes produced by the addition of different amphipaths or by changes in membrane structure. Clearance of cells in vivo as measured by 51Cr uptake in the spleen and liver correlated with the extent of shape alteration, either crenation or cupping. Whereas only 5%-i 0% of discoid cells were cleared by the spleen after 1 hr. there was 50%-80% clearance of severe echinocytes (crenated cells) and severe stomatocytes (cupped cells) primarily by the liver. This was not an effect of the crenating or cupping agents. since they were washed away prior to injection. and treatment of cells with the agents alone did not cause clearance. Further. if cells were