Figure 6.

A, inhibition of run-up current by glibenclamide. The K_ATP conductance was allowed to maximally activate under whole-cell recording conditions (0 mm[ATP]_i). Ordinate is membrane current (I_m) evoked by stepping from –80 to –40 mV (see inset) after run-up and in the presence of 0.3 nm glibenclamide. Inset shows membrane current in response to a 2 s step to –40 mV from V_h–80 mV followed by a 0.1 s step to –120 mV and ramp change in V_m to –40 mV (ramp 80 mV s⁻¹) before stepping back to V_h (protocol repeated every 20 s) at the points recording indicated by the asterisk. B, dose–response curve for the K_ATP current to tolbutamide. The curve was constructed from the mean IC₅₀ and slope values obtained from the individual cells. IC₅₀ and Hill slope values were 34.1 μm and 1.03, respectively. All points are mean ± s.e.m.