Mechanisms mediating CCK-8S-induced contraction of proximal colon in guinea pigs

Figure 3 Effects of CCK-8S on AP of PCSMCs. A-C and E: CCK-8S (10^-7 mol/L) suppressed the amplitude of AP to 38.6% ± 3.2% (n = 15, P < 0.01); A, B, D and F: CCK-8S (10^-7 mol/L) decreased fast repolarization times (T₉₀) by 36.9% ± 8.7% (n = 15, P < 0.01); A and E: Nifedipine (10^-5 mol/L) blocked the effects of CCK-8S on the amplitude of AP but failed to have any effect on T₉₀; B and F: Iberiotoxin (10^-6 mol/L) blocked the effects of CCK-8S on T₉₀ but failed to have any effect on the amplitude of AP; E and F: Pretreating SMCs with devazepide (10^-7 mol/L) blocked the CCK-8S-evoked effect on AP amplitude and T₉₀, whereas CI 988 had no such effect. ^aP < 0.01 vs control group (CaPSS); ^bP < 0.01 vs CCK-8S group; ^cP > 0.05 vs control group.