Fig. 2. Effects of different local anesthetics on membrane tension and the endocytosis rate. (a) Chemical structure of met-chlorpromazine, a membrane-impermeable local anesthetic, which intercalates mainly into the lipid in the exterior half of the bilayer and expands that layer relative to the cytoplasmic half, and chlorpromazine, its membrane-permeable analog, which expands the cytoplasmic half. (b) Tether force (left panel) and endocytosis rate, measured using fluorescence (right panel), in the presence of 30 µM chlorpromazine or met-chlorpromazine. (c) Tether force (left panel) and endocytosis rate (right panel) in the presence of 30 µM lidocaine or membrane-impermeable analog bromo-lidocaine. CPZ, chlorpromazine; M-CPZ, met-chlorpromazine.
