Figure 5.

Reversibility of 293B block of I_Ks. An SA node cell was repetitively depolarized every 30 s from a holding potential of −50 mV to +50 mV for 4 s. The amplitude of tail current elicited upon return to the holding potential was plotted as a function of time for the entire experiment. 293B at a concentration of 50 μM was added to the bath during the period indicated by the horizontal bar. The inset illustrates examples of the original current traces recorded at the time points indicated on the graph.