Effects of tertiary amine local anaesthetics on the phase behaviour of the dipalmitoylphosphatidylcholine model membrane. Electron spin resonance tetrametylpiperidinyloxyl partition study.

Using the electron spin resonance technique of the spin probe (TEMPO) is shown that local anaesthetics lidocaine, tetracaine, dibucaine, heptacaine and carbizocaine decrease the gel--liquid crystal phase transition temperature and increase the width of the phase transition of the dipalmitoylphosphatidylcholine (DPPC) model membrane. These effects roughly correlate with the efficiencies of the anesthetics to block action potential propagation in the nerves.