FIGURE 9.

luminal CCh induced Ca²⁺-dependent duodenal I _sc through serosal Ca²⁺ entry. (A) Summary data of vehicle (H₂O) or CCh (100 μM) -stimulated I _sc peak after mucosal application (n = 6). (B) Comparison between CCh-evoked I _sc peak after mucosal and serosal application. (C,D) luminal CCh-induced duodenal I _sc after atropine (10 μM, n = 6) added to the mucosal side. Ctrl represents the control without atropine treatment. (E,F) luminal CCh-evoked I _sc after extracellular Ca²⁺ omitted from the serosal or mucosal side (n = 6). Ctrl represents as the control in which normal extracellular Ca²⁺ was on both sides. (G) luminal CCh-evoked duodenal I _sc after mucosal addition of Nifedipine (Nif, 10 μM, n = 6). Ctrl represents the control without Nif treatment. Results are presented as mean ± SE. *p < 0.05, **p < 0.01, ***p < 0.001 vs. corresponding control by Student’s unpaired, two-tailed t-test.