Orally, 4 mg/day

The oocytes expressing select Ca channels were cultured for 2 to 4 days and then subjected to electrophysiological measurement. The oocytes were placed in a small chamber perfused with extracellular solution , and Ba2+ currents through expressed channels were measured by the two-microelectrode voltageclamp method. The experimental chamber was 0.5 ml in volume, and it was perfused continuously with the extracellular solution. Typically, oocytes were clamped at a holding potential of 2100, 280, or 260 mV and depolarized to 110 mV for 200 ms every 15 s. Microelectrodes were filled with 3 M KCl, and those showing a resistance of 0.5 to 1.2 VM were used. Benidine was evaluated in concentration range of 0.1 - 100 uM, and demonstrated blocking effect with IC50 of 0.7 uM.