Figure 3.

Sodium azide activates single potassium channels. (a) Cell attached recording from a single CRI-G1 cell, at 10 mV applied to the recording pipette. Continuous recording over a 20 min period showed that in the absence of any drugs there was no significant change in channel activity with time. Note that under these recording conditions channel openings are denoted as downward deflections (inward currents). In this and subsequent single channel recordings the symbol c refers to the closed state of the channel. (b) cell-attached recording of a CRI-G1 cell at 10 mV applied potential. Addition of sodium azide (3 mM) for the time indicated resulted in a rapid increase in channel activity, an action that was readily reversed by addition of tolbutamide (100 μM). (c) Graph of channel activity (Nf.Po) expressed as a function of time obtained from the cell-attached patches in a (▵) and b (•).