Decrease by psychotropic drugs and local anaesthetics of membrane fluidity measured by fluorescence anisotropy in Escherichia coli.

The effects of psychotropic drugs and local anaesthetics on the fluidity of Escherichia coli cell membranes were examined. Chlorpromazine was shown to increase 1,6-diphenyl-1,3,5-hexatriene fluorescence anisotropy, indicating that it decreased the membrane fluidity. This increase was significant at a temperature of more than 24 degrees C. Dibucaine, lignocaine, imipramine, tetracaine and procaine also increased the fluorescence anisotropy.