Decreasing Effect of Lidocaine·HCl on the Thickness of the Neuronal and Model Membrane.
This study examined the mechanism of action of a local anesthetic, lidocaine·HCl. Energy transfer between the surface fluorescent probe, 1-anilinonaphthalene-8-sulfonic acid, and the hydrophobic fluorescent probe, 1,3-di(1-pyrenyl) propane, was used to determine the effect of lidocaine·HCl on the thickness (D) of the synaptosomal plasma membrane vesicles (SPMV) isolated from the bovine cerebral cortex, and liposomes of the total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. The thickness (D) of the intact SPMV, SPMVTL and SPMVPL were 1.044±0.008, 0.914±0.005 and 0.890±0.003 (arbitrary units, n=5) at 37℃ (pH 7.4), respectively. Lidocaine·HCl decreased the thickness of the neuronal and model membrane lipid bilayers in a dose-dependent manner with a significant decrease in the thickness, even at 0.1 mM. The decreasing effect of lidocaine·HCl on the membrane thickness might be responsible for some, but not all of its anesthetic action.
Department of Dental Pharmacology and Biophysics, School of Dentistry and Research Institute for Oral Biotechnology, Yangsan Campus of Pusan National University, Yangsan 626-870, Korea.
Sung-Min
SM
Park
Jong-Sun
JS
Park
Jae-Han
JH
Kim
Jin-Hyun
JH
Baek
Tae-Gyun
TG
Yoon
Do-Keun
DK
Lee
Won-Hyang
WH
Ryu
In-Kyo
IK
Chung
Uy Dong
UD
Sohn
Hye-Ock
HO
Jang
Il
I
Yun
Fluorescence quenching technique; Lidocaine·HCl; Membrane thickness; Model membranes; Neuronal membranes