MEMBRANE OSCILLATIONS AND ION-TRANSPORT

Oscillations observed at such membranes in the absence of any channel like substances as liquid membranes, lipid-doped Millipore filters, artificial bilayer lipid membranes (BLM), etc. are reviewed with the intention of extracting the fundamental information significant for the understanding of oscillations at biomembranes in living organisms. Since the ion transfer at the aqueous/membrane interface and the interfacial adsorption are deeply concerned with the oscillations (especially those at liquid membranes), an outline is given on the voltammetry for the ion transfer at an interface of two immiscible electrolyte solutions, (VITES), which is very powerful in the elucidation of the ion transfer processes and the adsorption phenomena. The ion transfer through a liquid membrane or a BLM is also discussed based on the results obtained by the VITIES. The usefulness of the VITIES and the voltammetric concept in the elucidation of mechanisms of oscillations is demonstrated taking, for an example, the analysis of novel oscillations of membrane potential and membrane current found recently by the authors with liquid membranes under applied currents or potentials. One of the novel oscillations which was observed with the transfer of Na+ showed characteristics similar to those of the oscillation at a biomembrane with ''sodium channel''.