The interaction of urethane, an intravenous general anaesthetic, with phosphatidylcholine membranes

The interaction of urethane (C2H5OCONH2), a neutral, intravenous general anaesthetic, with model membranes of egg-yolk phosphatidylcholine has been examined by 2H-NMR spectroscopy of deuterium-labelled lipids and anaesthetic as well as by 31P-NMR spectroscopy. Urethane interacts at the membrane/water interface to increase the interlipid separation in the bilayer. The presence of cholesterol does not significantly alter this behaviour. However, cholesterol does act to displace urethane from a second weakly bound membrane site which is in fast exchange with urethane free in bulk aqueous solution.