Fig. 6. The cell-free, inside-out patch clamp recording configuration was used to assess the effects on K_ATP channel open-state probability (P_o) of the NO donor SNAP (100 µmol l^-1; left), the stable cGMP analog 8-Br-cGMP (200 µmol l^-1) and 8-Br-cGMP in combination with the K_ATP antagonist BDM (60 µmol l^-1; right), all under normoxic conditions. Three min exposure to SNAP at the intracellular face of the membrane significantly increased P_o (N=6). The cGMP analog also raised P_o (N=4), an effect that was substantially eliminated by simultaneous administration of the K_ATP antagonist (N = 4). Values are means ± 1 S.E.M. ^*, significantly different from control (P<0.05).