Figure 1. Activation of muscarinic receptors induced extracellular Ca²⁺ entry through possible pathways.

(A) Representative of the time course of CCh-stimulated murine duodenal mucosal I_sc after extracellular Ca²⁺ was omitted from the serosal side or the mucosal side of the duodenal tissues. (B) The summary data of CCh-stimulated duodenal I_sc peak after Ca²⁺ omission from the mucosal side, the serosal side or both sides of duodenal tissues. (C–E) Effects of AMG-517 (AMG, 100 M) (C), RN-1734 (RN, 3 M) (D) and KBR-7943(KBR, 3 M) (E) on CCh-induced duodenal I_sc peak after serosal addition. Results are presented as mean SE (n = 6–9 in each series). NS, no significant differences, ^****P < 0.0001 vs. control by Student’s t-test.