Figure 8. Effect of 5-HT₄ receptor or GLP-2 receptor antagonist on acetate-induced HCO₃⁻ secretion.

GR113808 (1 mg kg⁻¹) was injected i.v. at t = 0 min, whereas GLP-2(3–33) was injected i.v. (3 nmol kg⁻¹, i.v.) at t = 10 min, followed by luminal acetate (0.1 mm) perfusion. GR113808 (A) or GLP-2(3–33) (B) had little effect on acetate-induced HCO₃⁻ secretion. Pre-treatment of both antagonists reduced acetate-induced HCO₃⁻ secretion (C). Each data point represents the mean ± SEM (n = 4–6 rats). *P < 0.05 vs. pH 7.0 Krebs group. ^†P < 0.05 vs. Acetate group.