[Membrane permeability to aminazine and nonachlazine]

Model phospholipid vesicles (liposomes) and the fluorescent probe p-terphenyl were used to study membrane permeability by phenothiazine anesthetics. The anesthetics quenched the fluorescence of the probe bound to the membrane. The extent of the quenching depended on the quenching ability to penetrate the lipid bilayer. Aminazin was able to penetrate the lipid bilayer, while nonachlazin was not. This may be accounted for by the presence of two nitrogen atoms capable of binding to H+ in the nonachlazin molecule in contrast to one nitrogen atom in the aminazin molecule.