Interaction of local anesthetics with bilayer phospholipid membranes

Local anesthetics--cocaine, lidocaine, novocaine were tested for conductivity of bilayer lipid membranes containing anion-selective channels formed by polyene antibiotic amphotericin B. It has been shown that 5 X 10(-4) M cocaine doubles the membrane conductance. The line of efficiency of the tested anesthetics is: cocaine greater than lidocaine greater than novocaine. Possible molecular mechanism of the discovered effect is discussed.