title: Dielectric properties of dipicrylamine-doped erythrocytes, cultured cells and lipid vesicles.
abstract: Horse erythrocytes, murine lymphoblasts (L5178Y) and lipid vesicles that were treated with dipicrylamine (DPA) as a lipophilic ion were studied by dielectric spectroscopy over a frequency range of 10 Hz to 10 MHz. The DPA-treated cells and lipid vesicles showed low-frequency (LF) dielectric dispersion around 1-10 kHz in addition to β-dispersion due to the Maxwell-Wagner effect. The LF dispersion corresponds to that found in previous electrorotation (ROT) studies on DPA-treated cells, being due to the translocation of mobile ions in the plasma membranes. Analysis of the LF dispersion based on the mobile charge model provided the area-specific concentration Nt of DPA ions adsorbed at the membrane interfaces and their translocation rate constant ki between the interfaces. The values of Nt and ki were respectively 13-21 nmol/m(2) and 0.7-1.6×10(4) s(-1) for both horse erythrocytes and L5178Y cells at 10 μM DPA, being consistent with those determined by ROT for human erythrocytes and cultured cells.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan. asami@e.kuicr.kyoto-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Asami
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000502:physiology*; D002478:Cells, Cultured; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects*; D006736:Horses; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects*; D051379:Mice; D008954:Models, Biological; D010851:Picrates / Q000494:pharmacology*; D012399:Rotation; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D010851:Picrates; D053835:Unilamellar Liposomes; C011454:dipicrylamine