Effect of the local anesthetic heptacaine hydrochloride on the structured water in model phosphatidylcholine membrane: 2D-NMR and 31P-NMR study.
Interaction of the local anesthetic 1[2-(2-heptyloxyphenyl-carbamoyloxy)-ethyl] piperidinium chloride (heptacaine hydrochloride) with a model membrane formed by phosphatidylcholine was studied using 2D-NMR spectra of heavy water and 31P-NMR proton-decoupled and undecoupled spectra of the lipid phosphate group. Heptacaine hydrochloride was found to increase the number of water molecules oriented over the polar region of the membrane, to increase the order parameter of the lipid phosphate group, as well as that of oriented water, and to increase the volume of unoriented water trapped between the bilayers. Heptacaine hydrochloride also affects the temperature dependence of quadrupolar splitting of oriented heavy water deuterons. Heptacaine hydrochloride is suggested to expand the membrane laterally and to charge the membrane surface electrostatically.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003903:Deuterium; D009682:Magnetic Resonance Spectroscopy; D010713:Phosphatidylcholines; D010759:Phosphorus Isotopes; D010880:Piperidines; D013696:Temperature; D014867:Water
D010713:Phosphatidylcholines; D010759:Phosphorus Isotopes; D010880:Piperidines; D014867:Water; C013549:heptacaine; D003903:Deuterium