Membrane deformability and the capacity for shape change in the erythrocyte
JA Chasis and SL Schrier
Department of Medicine, University of California, San Francisco 94143-
0128.
Erythrocytes must have the capacity to undergo marked membrane deformation
and shape changes in order to circulate through capillaries and respond to
a range of shear stresses. To study the interrelationships between membrane
deformability and the capacity for shape transformation, we created rigid
membranes using several agents and then examined the ability of these
erythrocytes with rigid membranes to undergo amphipath-induced shape
change. We have previously shown that wheat germ agglutinin (WGA) and a
monoclonal antibody to glycophorin A (R-10) cause membrane rigidity as
measured by ektacytometry. Experiments were therefore designed to produced
comparably rigid membranes using WGA, R-10, and diamide, and then to test
the ability of lysophosphatidylcholine to produce echinocytes, and
primaquine to produce stomatocytes. We found that diamide treatment
substantially blocked both types of shape change. In contrast, R-10 binding
did not impair either primaquine- or lysophosphatidylcholine- induce shape
change. Further, WGA blocked echinocyte transformation, as previously
reported, but not stomatocytosis. Using reduced and unreduced gel
electrophoresis and Triton extraction, we compared the biochemical changes
associated with WGA-, diamide-, and R-10-induced rigidity, and found them
to be different. We conclude that not all rigid cells are incapable of
shape change, and therefore that decreased membrane deformability is not
predictive of impaired capacity for shape change.
Volume 74,
Issue 7,
pp. 2562-2568,
11/15/1989
Copyright © 1989 by The American Society of Hematology
