Fig. 5. Effects of KATP channel blockers or a channel opener on pituitary adenylate cyclase-activating peptide (PACAP)-mediated inhibition of pacemaker potentials recorded in cultured interstitial cells of Cajal (ICC) from mouse colon. (A) Glibenclamide (an ATP-sensitive K+ channel blocker; 10 µM) blocked PACAP-induced membrane hyperpolarization and reduced the frequency of pacemaker potentials. (B) Pinacidil (100 nM) reduced the frequency of pacemaker potentials and induced hyperpolarization of the cell membrane in colonic ICC. Glibenclamide (10 µM) blocked the pinacidil-induced action. Vertical solid lines show the amplitude of the pacemaker potentials and horizontal solid lines show the duration of recording (s) of pacemaker potentials. (C) and (D) summarize the effects of PACAP on pacemaker potentials in colonic ICC with KATP channel blockers. Bars represent the means±SE. *Asterisks indicate a statistically significantly difference from controls (p<0.05). Con, control.
