Figure 4.
Effect on the inward current of the dihydropyridine compound nifedipine and of a substitution of Ba2 + for Ca2 + . (A) Currents were obtained on the same cell in response to a voltage pulse to +10 mV from a holding potential of –70 mV. The star indicates the current evoked after addition of 1 μM nifedipine in the external solution. (B) Currents were evoked on the same cell in response to a voltage pulse to +10 mV from a holding potential of –70 mV. The star indicates the current evoked after substitution of 6 mM Ba2+ for 6 mM Ca2+ in the external solution.