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T Itoh, S Chien and S Usami
Department of Physiology and Cellular Biophysics, College of Physicians and
Surgeons, Columbia University, New York, NY.
Although the rheologic behavior of sickle erythrocytes (SS cells) is highly
dependent on oxygen tension (pO2) and temperature, very little data exist
regarding the effects of deoxygenation and reoxygenation on the rheology of
"individual" SS cells at body temperature. We have devised and assessed a
new experiment system, in which micropipette aspiration can be performed on
individual cells in a constant- temperature chamber that has ports for
changing media with different pO2 (effected in 30 to 120 seconds) and
sensing probes for monitoring pO2 and temperature. This system enabled us
to simultaneously alter and monitor pO2 at 37 +/- 0.5 degrees C, and to
monitor and study a single cell under microscopic observation. The static
rigidity (E) and dynamic rigidity (eta) of individual SS cells were
determined by repeated aspirations of the same cell under various pO2. With
stepwise reductions in pO2, E and eta showed no significant changes before
sickling, but once sickled, their values markedly increased by 10(2)- to
10(3)-fold concomitantly with morphologic alteration of the cell. Thus, the
deformability of a single SS cell behaves in an "all or none" manner at a
critical pO2, and earlier studies on the effect of deoxygenation on the
rheology of SS cell suspensions probably reflect the overall behavior of SS
cells with widely distributed critical pO2.
This article has been cited by other articles:
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| Copyright © 1992 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
