Figure 3.

Inhibition of K_v1.4 potassium channel by 1a and 2a. A. Representative K⁺ channel current traces from three experiments showing inhibition of K_v1.4 potassium channel by N-3-phenylpropyl derivatives of N-alkylamines. HEK-293 cells were transfected with both the sigma-1 receptor and K_v1.4 potassium channel. K⁺ channels were activated by 400 ms pulses to +20 mV from a resting potential of −80 mV. B. Concentration response curves of butylamine, heptylamine and their N-3-phenylpropyl derivatives. The leftward shift of the response curve for the N-3-phenylpropyl derivatives corresponds with the relative increase in affinity at the sigma-1 receptor.