Effect of lanthanum on red blood cell deformability.
Prior reports describing the effects of lanthanum (La(3+)) on red blood cells (RBC) have focused on the effects of this lanthanide on cell fusion or on membrane characteristics (e.g., ion movement across membrane, membrane protein aggregation); the present study explores its rheological and biophysical effects. Normal human RBC were exposed to La(3+) levels up to 200 microM then tested for: (1) cellular deformability using a laser-based ektacytometer and an optical-based rheoscope; (2) membrane viscoelastic behavior via micropipettes; (3) surface charge via micro electrophoresis. La(3+) concentrations of 12.5 to 200 microM caused dose-dependent decreases of deformability that were greatest at low stresses: these rheological changes were completely reversible upon removing La(3+) from the media either by washing with La(3+)-free buffer or by suspending La(3+)-exposed cells in La(3+)-free media (i.e., viscous dextran solution). Both membrane shear elastic modulus and membrane surface viscosity were increased by 25-30% at 100 or 200 microM. As expected, La(3+) decreased RBC electrophoretic mobility (EPM), with EPM inversely but not linearly associated with deformability; changes of EPM were also completely reversible. These results thus indicate novel aspects of RBC cellular and membrane rheological behavior yet raise questions regarding specific mechanisms responsible for La(3+)-induced alterations.
Alexy
Tamas
T
Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Nemeth
Norbert
N
Wenby
Rosalinda B
RB
Bauersachs
Rupert M
RM
Baskurt
Oguz K
OK
Meiselman
Herbert J
HJ
D001809:Blood Viscosity / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004548:Elasticity; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D004907:Erythrocyte Deformability / Q000187:drug effects*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology; D018056:Hemorheology / Q000187:drug effects; D006801:Humans; D007811:Lanthanum / Q000494:pharmacology*
D007811:Lanthanum