Effects of exogenous H2O2 on the normalized single-channel open and closed properties of Kir6.2/SUR2A channels in intact HEK293 cells in the absence and presence of CaMKII inhibition.

Single-channel recordings of Kir6.2/SUR2A channels in cell-attached patches obtained from transfected HEK293 cells were performed at −60 mV in symmetrical 140-mM K+ solutions. H2O2 (1 mM) or H2O2 (1 mM) plus the myristoylated inhibitory peptide for CaMKII mAIP (1 µM) was applied by bath perfusion using a pressure-driven perfusion system. The single-channel properties were obtained as described in Methods. All values were normalized to the corresponding controls obtained in individual patches prior to index drug application (control taken as 1), averaged and are presented as mean ± SEM. Significance levels are:*, P**, P****, Pt tests).