Prior reports describing the effects of lanthanum (La3+) 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 La3+ levels up to 200 μM 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 μM caused dose-dependent decreases of deformability that were greatest at low stresses: these rheological changes were completely reversible upon removing La3+ from the media either by washing with La3+-free buffer or by suspending La 3+-exposed cells in La3+-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 μM. As expected, La3+ 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 La3+-induced alterations.
|Original language||English (US)|
|Number of pages||13|
|State||Published - 2007|
- Red blood cell