The effect of the selective 5-HT3 receptor agonist on ferret gut motility

Abstract The effect of the selective 5-hydroxytryptamine (5-HT) 3 receptor agonist YM-31636 (2-(1 H -imidazol-4-ylmethyl)-8 H -indeno[1,2- d ]thiazole monofumarate) on gut motility of fed ferrets was investigated. YM-31636 (0.1 mg/kg p.o.) induced a giant migrating contraction (GMC)-like, high-amplitude, ungrouped colonic contraction although it did not change the basal colonic motility pattern. This GMC-like contraction was always accompanied by defecation. Both GMC-like contraction and defecation were inhibited with the selective 5-HT 3 receptor antagonist ramosetron. YM-31636 affected gastric, duodenal and ileal motility pattern only slightly. These results suggest that 5-HT 3 receptor agonists such as YM-31636 are useful in treating constipation since they facilitate GMC-like contractions and defecation without undesired changes in gut motility pattern.