Evidence for Inhibitory Effects of Flupirtine, a Centrally Acting Analgesic, on Delayed Rectifier K+ Currents in Motor Neuron-Like Cells
Figure 6
Stimulatory effect of Flu on M-type K+ current () in NSC-34 cells. In these experiments, cells were bathed in Ca2+-free Tyrode’s solution and the pipette was filled with a K+-containing solution. (A) Current traces obtained in the absence (a) and presence of 1 and 3 M Flu. The inset indicates the voltage protocol used. (B) Summary of the data showing effects of Flu and linopirdine on measured at −50 mV (left) and −20 mV (right) in NSC-34 cells (mean ± SEM; –13 for each point). Flu: flupirtine; Lino: linopirdine. *Significantly different from controls. **Significantly different from Flu (3 M) alone group. (C) Voltage dependence of activation in the absence (■) and presence (□) of 3 M Flu (mean ± SEM; –10 for each point). The smooth dashed lines represent the best fits to the Boltzmann equation described in Section 2. Notably, addition of Flu can shift the activation curve of to the hyperpolarizing voltage with no change in the gating charge of this current.
