Figure 6. The whole-cell outward K+current in a canine tracheal smooth muscle cell dialyzed with 1.8 mM CaCl2and 2.5 mM EGTA before (A) and after (B) exposure to 40 nM charybdotoxin. The The whole-cell outward K (+) currents were generated by depolarizing pulses to -40, -20, 0, +20, +40, and +60 mV from a holding potential of -70 mV. (C) Relative peak current-voltage relations obtained before and after exposure to 40 nM charybdotoxin. Symbols represent the mean +/− SD (n = 4).