Figure 4.

Diltiazem abolishes VDCC currents in 10 mM [Ba²⁺]_o ± 100 μM [Ca²⁺]_o. VDCC currents elicited by depolarizing voltage steps to +10 mV from a holding potential of −80 mV in bath solutions containing 10 mM [Ba²⁺]_o (A) or 10 mM [Ba²⁺]_o plus 100 μM [Ca²⁺]_o (B). Traces in red represent currents obtained in cells prior to the addition of diltiazem. Traces in blue represent current traces obtained in cells following washout of 100 μM diltiazem. (C) Concentration-inhibition curves of diltiazem on VDCC currents obtained in extracellular solution containing 10 mM [Ba²⁺]_o ± 100 μM [Ca²⁺]_o.