title: Effect of a local anesthetic lidocaine hydrochloride on the bilayer structure of phospholipids.
abstract: The effect of a local anesthetic, lidocaine hydrochloride (LC x HCl), on the bilayer systems of purified egg phosphatidylcholine (EPC), dipalmitoylphosphatidylcholine (DPPC) and dioleoylphosphatidylcholine (DOPC) was studied by means of small-angle X-ray scattering (SAXS), Prodan fluorescence and electrophoretic light scattering. In the liquid crystalline phase of EPC and DOPC bilayers, the contraction of lamellar distance by ca. 0.8-1.0 nm and the decrease of average vesicle size were observed in the presence of LC x HCl. The adsorption of LC x HCl on the vesicle interface brought about the lateral expansion of bilayers and the decrease in the radius of curvature of vesicles. The contraction in the lamellar distance of EPC bilayer caused by high concentration of LC x HCl is attributable to the chain folding in the liquid crystalline state. In the gel phase of DPPC bilayer, the contraction of the lamellar distance in the presence of 0.37 M LC x HCl amounts to 1.6 nm, and the emission maximum of Prodan fluorescence was red-shifted from 440 nm to 518 nm. These phenomena are attributed to the formation of LC x HCl-induced interdigitated gel phase.
authors.affiliation: Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Takeda
authors.forename: You
authors.initials: Y
authors.lastname: Sano
authors.forename: Sosaku
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Hirata
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Matsuki
authors.forename: Shoji
authors.initials: S
authors.lastname: Kaneshina
mesh_terms: D000779:Anesthetics, Local / Q000737:chemistry*; D008012:Lidocaine / Q000737:chemistry*; D008027:Light; D008051:Lipid Bilayers / Q000737:chemistry*; D015394:Molecular Structure; D009997:Osmotic Pressure; D010743:Phospholipids / Q000737:chemistry*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D014961:X-Ray Diffraction
chemical_list: D000779:Anesthetics, Local; D008051:Lipid Bilayers; D010743:Phospholipids; D008012:Lidocaine