title: Microelectrode-based dielectric spectroscopy of glucose effect on erythrocytes.
abstract: The dielectric response of biconcave erythrocytes exposed to D-glucose and L-glucose has been investigated using a double array of planar interdigitated microelectrodes on a glass microchip. Erythrocytes are analyzed under physiological conditions suspended in hypo-osmolar balanced solutions containing different glucose concentrations (0-20 mM). The glucose effect on the cellular dielectric properties is evaluated by analyzing the spectra using two different approaches, the equivalent circuit model and a modified model for ellipsoidal particles. The results show that at elevated glucose concentration (15 mM) the membrane capacitance increases by 36%, whereas the cytosol conductivity slightly decreases with a variation of about 15%. On the contrary, no variation has been registered with L-glucose, a biologically inactive enantiomer of D-glucose. The paper discusses the possible mechanism controlling the membrane dielectric response. As the external D-glucose increases, the number of activated glucose transporter in the erythrocyte membrane raises and the transition from sugar-free state to sugar-bounded state induces a change in the dipole moments and in the membrane capacitance.
authors.affiliation: Microsystems Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland. ludovica.colella@epfl.ch
authors.forename: L
authors.initials: L
authors.lastname: Colella
authors.forename: C
authors.initials: C
authors.lastname: Beyer
authors.forename: J
authors.initials: J
authors.lastname: Fröhlich
authors.forename: M
authors.initials: M
authors.lastname: Talary
authors.forename: P
authors.initials: P
authors.lastname: Renaud
mesh_terms: D003600:Cytosol / Q000187:drug effects; D058266:Dielectric Spectroscopy / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D025802:Electric Capacitance; D004553:Electric Conductivity; D004910:Erythrocyte Membrane / Q000187:drug effects*; D004912:Erythrocytes / Q000187:drug effects* / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D008839:Microelectrodes; D009004:Monosaccharide Transport Proteins / Q000032:analysis
chemical_list: D009004:Monosaccharide Transport Proteins; D005947:Glucose