title: Influence of anaesthetics on the movement of the mobile charges in the algal cell membrane of Valonia utricularis.
abstract: Voltage relaxation studies in the presence of anaesthetics were performed on cells of the giant marine alga Valonia utricularis using intracellular microelectrodes. From the decay of the initial membrane voltage which can be described by two relaxation processes the conclusion can be drawn that protein-linked, mobile charges are present which are probably involved in turgor-pressure-dependent potassium transport (Büchner, K.-H., Rosenheck, K. and Zimmermann, U. (1985) J. Membrane Biol. 88, 131-137). The anaesthetics halothane and chloroform were found to affect reversibly, procaine and tetracaine irreversibly the translocation rate k of the mobile charges at concentrations which were equal to (for halothane and chloroform) or significantly below (for procaine and tetracaine) clinical and nerve blocking levels. The concentration of the mobile charges Nt as well as the specific membrane resistance Rm and the specific membrane capacitance Cm remained unchanged in these concentration ranges. The data suggest a specific interaction of anaesthetics with specialized target sites of a transport protein to which the mobile charges are coupled.
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D002725:Chloroform / Q000494:pharmacology; D004563:Electrochemistry; D004594:Electrophysiology; D056890:Eukaryota / Q000502:physiology*; D006221:Halothane / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D011343:Procaine / Q000494:pharmacology; D013748:Tetracaine / Q000494:pharmacology
chemical_list: D000777:Anesthetics; D013748:Tetracaine; D011343:Procaine; D002725:Chloroform; D011188:Potassium; D006221:Halothane