Abstract
Echinocytosis in RBC's from A & N were quantitated by l)photo-microscopy; 2)frequency histograms of the 6 stages of disc-sphere transformation, scored from 0-5; and 3)morphologic index (MI), the mean score for 200 cells. One hr. after adding Ca ionophore A23187 to cells in isotonic media with 100 μM free Ca and 90 mM Kex, the MI was 1.7 ± 0.5 (S.D., 5 donors) for N and 4.2 ± 0.2(6) for A (P<0.0005). Under equivalent conditions, net 45Ca uptake, cell deformabi1ity as measured by the Ektocytometer, and ATP decline were comparable for A & N. In contrast to Ca, the potencies of 2 echinocytogenic drugs(phloridzin & dinitrophenol) were similar for A & N. While Ca causes a progressive shape change with heterogeneous cell populations, the 2 drugs caused an immediate and stable E with homogeneous cell populations. E caused by the 2 drugs and by Ca were all reversible by the cupping agent, chlorpromazine. Preservation of ATP by 0.5 mM vanadate showed low ATP was not required for Ca-induced E. Vanadate also abolished the inhibition of Ca-induced E in cells from N. In cells treated with Ca and A23187, Mg suppressed E without vanadate, but had no effect with vanadate. These observations are consistent with a model of Ca-induced E whereby Ca-activated phospholipase(s) is counterbalanced by a Mg and vanadate-sensitive repair process, with more active repair in red cells of N as compared with A. The results define a new difference between red cells from A & N, and suggest that cells from N are a useful variant for understanding the mechanism of Ca-induced E. (Supported in part by AHA/Upstate New York Chapter).
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Bifano, E., Becker, S. & Freedman, J. 884 CALCIUM-INDUCED ECHINOCYTOSIS(E)IN HUMAN RED BLOOD CELLS FROM NEONATES(N) AND ADULTS(A). Pediatr Res 19, 258 (1985). https://doi.org/10.1203/00006450-198504000-00914
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DOI: https://doi.org/10.1203/00006450-198504000-00914