Age-related changes in deformability of human erythrocytes
SP Sutera, RA Gardner, CW Boylan, GL Carroll, KC Chang, JS Marvel, C Kilo, B Gonen and JR Williamson
The present study was designed to further the characterization of age-
related changes in the deformability of human erythrocytes. The top
(approximately young) and bottom (approximately old) 10% fractions of
density-separated red cells from ten normal donors were subjected to graded
levels of shear stress in a rheoscope. Measurements were made of
steady-state elongation (cells tank treading in a state of dynamic
equilibrium) and the time course of shape recovery following abrupt
cessation of shear. In parallel with the rheologic experiments, several
physical and chemical properties were assayed to determine correlates of
mechanical properties. These included mean cell volume, mean corpuscular
hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane
proteins, and membrane phospholipid and protein concentration. The
microrheologic observations revealed that only about 90% of the old cells
retained their capacity to tank tread. However, the tank-treading cells
elongated less than their younger counterparts at corresponding levels of
shear stress, thus demonstrating a reduced level of deformability. Further
analysis of the data indicates that increases in membrane viscosity and
elastic modulus along with a significant loss in excess surface area
contribute to the limitation of the ability of the older cells to change
shape.
Volume 65,
Issue 2,
pp. 275-282,
02/01/1985
Copyright © 1985 by The American Society of Hematology
