Figure 7.

Agonist-independent activation of I_K^+Ach by 100 μM of GTP[γS] in inside-out patches excised from WT, α_i2-null, and α_i3-null cells. Shown are typical current traces recorded before (basal) and after addition of GTP[γS] to the bath solution. Activation of I_K^+ATP was blocked by addition of Mg-ATP (200 μM) to the bath solution. Quantitative estimates of channel activity expressed as NP_o are shown in the bottom panel. Bars are the mean ± SE (n = 5–6) before (basal) and after addition of GTP[γS].