Fig. 2. Time course of the effect of 2,4-dinitrophenol (DNP) on the KATPchannel. The time-dependent effect of DNP on KATPchannel activity was monitored in a cell-attached patch as described in figure 1. The times shown in the brackets denote the period at which channel activity was recorded. The sample recording was obtained from one patch exposed to 150 μm DNP and monitored over the time period depicted.