[The action of aminobenzoic acid derivatives on the ion currents in myelinated nerves. 1. Dose-response relationship].

Effects of Aminobenzoic Acid Derivatives on the Ionic Currents in Myelinated Nerve/1st Communication: Dose-response curves Derivatives of aminobenzoic acid were modified and their blocking potencies on the ionic currents of single potential clamped myelinated nerve fibres were tested by means of dose-response curves. Starting from metacaine (ethyl m-aminobenzoate), derivatives of different basicity were produced by N-dimethylization, N-quarternization and by preparing a corresponding aliphatic amine. The corresponding free acids and the structural isomers of metacaine were tested as well. The physico-chemical properties of the derivatives were characterized by their pKa-values and their octanol/water partition coefficients. Our findings suggest that the site of action of the aminobenzoic acids tested is located at the inside of the nerve membrane. Moreover, no indications of binding to a receptor in a pharmacological sense were found.