Figure 8.

Factors that changed the amplitude of transient outward currents elicited on repolarization in the presence of 500 μM internal Put. (A) Currents recorded by depolarizing the membrane from a holding potential of −120 mV to 0 mV for various durations (from 100 to 500 ms by 100-ms increment), and then repolarizing it to −50 mV. The inward capacitive currents and the transient increase in the outward currents (arrows) observed on the step to −50 mV are superimposed. The inward current at the holding potential (−120 mV) does not appear in the trace. (B) Currents recorded as those in A with a holding potential of −80 mV. Currents in A and B were obtained from the same cell. (C) Currents recorded as in B using the pipette solution containing neither Mg²⁺ nor Put. No transient increase is observed in the outward currents on repolarization to −50 mV.