A Comparative Study of Widely Used Anesthetics on Lipid Membrane Fluidity

In this study, the effects of anesthetic drugs propofol and sevoflurane on lipid membrane fluidity are compared with that of isoflurane. To get a basic picture, the simplest lipid membrane of DPPC was chosen. Lipid membranes were labeled with dipyrene-PC fluorescent probe, whose excimer/monomer (E/M) fluorescence peak ratio showed an immediate increase after adding the drugs, indicating a sharp increase of membrane fluidity. We studied clinical concentrations of 10 µM propofol, 0.5 mM sevoflurane and 1 mM isoflurane. The fluidity increases at these concentrations on DPPC lipid bilayer are comparable, and all drugs are quite effective to loosen up the highly ordered lipid domains of saturated lipids.