cells express L-type VDCC. (a) Representative microphotographs of monolayer cell cultures of permanently transfected CHOC cells (left) and wild-type CHO cells (right). . (b) Representative current traces evoked by depolarizing voltage steps of 40 ms duration from −60 to from a holding potential of −80 mV in a CHOC cell (left) and a wild-type CHO cell (right). The external solution contained 5 mM CaCl2. This protocol evoked voltage-dependent calcium current in the permanently transfected cell, while no current was present in CHO cell of the wild-type. (c) Characterization of the Ca current in CHOC cell. The current was increased by more than 50% when the external solution was changed from 5 mM CaCl2 to 5 mM BaCl2, and it was reversibly blocked by nimodipine. Current traces evoked by 50 ms depolarizing steps from −80 mV (holding potential) to in the three conditions are shown on the left. The graph on the right shows the time course of the experiment.
