The Effect of Lidocaine·HCL on the Physical Properties of Liposomes of Total Lipid and Phospholipids Extracted From Neuronal Membranes

Abstract

Fluorescent probe techniques were used to evaluate effect of lidocaine·HCl on physical properties (asymmetric lateral and rotational mobilities, membrane thickness) of liposomes of total lipid(SPMVTL) and phospholipids(SPMVPL) extracted from synaptosomal plasma membrane vesicles(SPMV). An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane(Py-3-Py), 1,6-diphenyl-1,3,5-hexatriene(DPH) by trinitrophenyl groups. Membrane thickness was measured by using energy transfer between the surface fluorescent probe 1-anilinonaphthalene-8-sulfonic acid(ANS) and hydrophobic fluorescent probe Py-3-Py. Lidocaine·HCl increased bulk lateral and rotational mobilities, and had a greater fluidizing effect on the inner than outer monolayer of liposome. Thickness of SPMVTL, SPMVPL lipid bilayer have been decreased by lidocaine·HCl, which means that membranes have been expanded. The sensitivities to increasing effect of lateral and rotational mobilities of liposomal lipid bilayer by local anesthetic differed depending on the native and model membranes in the descending order of SPMV, SPMVPL and SPMVTL. These effects are not only due to the influence of local anesthetic on lipids, but they are magnified by the interaction between lipids, proteins and water.