Roles of ROS, calmodulin and CaMKII in mediating the stimulatory effects of PKG on the normalized single-channel open and closed properties of recombinant Kir6.2/SUR2A channels expressed in intact HEK293 cells.

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. Zaprinast (50 µM), or zaprinast plus KT5823 (1 µM), MPG (500 µM), catalase (500 U/ml), SKF-7171 (10 µM), or mAIP (1 µM), was applied by bath perfusion using a pressure-driven 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****, Pt tests).