Membrane-buffer partition coefficients of a local anesthetic tetracaine monitored by an anesthetic sensor; effects of temperature and pH.
Binding of a local anesthetic tetracaine (TC) to dimyristoylphosphatidylcholine (DMPC) bilayer membrane was studied by the potentiomerty with an ion-selective electrode sensitive to TC cation. DMPC membrane-buffer partition coefficient (K(app)) was determined in mole fraction unit as a function of pH for the lamellar gel (at 12 degrees C), ripple gel (at 20 degrees C), and liquid crystal (at 30 degrees C) phases. The partition coefficients of charged (K+) and uncharged TC (K0) into the DMPC membranes were estimated from the pH-dependence of K(app). The three states of DMPC membranes were more receptive to the uncharged TC than the charged species.
Satake
H
H
Center for Cooperative Research, The University of Tokushima, Minamijosanjima, Japan.
Kageyama
T
T
Matsuki
H
H
Kaneshina
S
S
D000465:Algorithms; D000779:Anesthetics, Local / Q000737:chemistry*; D002021:Buffers; D004134:Dimyristoylphosphatidylcholine; D006863:Hydrogen-Ion Concentration; D011199:Potentiometry; D013696:Temperature; D013748:Tetracaine / Q000737:chemistry*
D000779:Anesthetics, Local; D002021:Buffers; D013748:Tetracaine; D004134:Dimyristoylphosphatidylcholine