Figure 6.

Effects of AA and 4-AP on heterologously expressed cKv4.2. A, The transient current generated in a CHO cell, by depolarizing the membrane to 27 mV from a holding potential of -93 mV, was partially blocked with 20 μm AA. This block was reversed by washing the cell in 1 mg/ml BSA. B, The transient current generated in CHO cells was sensitive to 4-AP, as shown by a partial block with 10 mm 4-AP when the cell was depolarized to a membrane potential of -3 mV from a holding potential of -83 mV. C, The dose-response relationship is plotted as the percentage of the transient current blocked by various concentrations of 4-AP. A curve fit was generated using the Michaelis-Menten equation, which revealed that half the channels were blocked with 11 mm 4-AP (k = 0.71). Numbers in parentheses indicate numbers of cells tested.