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

Figure 6 Effects of CCK-8S, nifedipine and devazepide on I_Ca-L in PCSMCs. A: Current traces of I_Ca-L were recorded from -40 mV to +30 mV during 400 ms depolarization; B: CCK-8S enhanced I_Ca-L in a concentration-dependent manner (EC₅₀ = 3.2 × 10^-8 mol/L); CCK-8S (10^-7 mol/L) increased I_Ca-L depolarized from -40 mV to +10 mV (from 60 ± 8 pA to 84 ± 11 pA; n = 8); C: CCK-8S-intensified I_Ca-L was markedly suppressed by devazepide (10^-7 mol/L), nifedipine (10^-5 mol/L), TG and BA (10^-5 mol/L); D: Current-voltage curves of whole-cell patch clamp under each condition. Compared with control, CCK-8S (10^-7 mol/L) significantly enhanced I_Ca-L, whereas devazepide, nifedipine, TG and BA inhibited I_Ca-L. ^aP < 0.05 vs control group (CaPSS).