The role of 5-hydroxytryptamine3 and 5-hydroxytryptamine4 receptors in the regulation of gut motility in the ferret.

The role of 5-hydroxytryptamine (5-HT)3 and 5-HT4 receptors in the regulation of gut motility in the ferret was investigated. The selective 5-HT3 receptor antagonist ramosetron (1 - 10 microg/kg s.c.) prolonged the interval of gastric antral migrating motor complex, but had only slight effect on small intestinal and colonic motility in unfed animals. The selective 5-HT4 receptor antagonist SB 204070 did not affect motility throughout gut in unfed animals. Neither ramosetron nor SB 204070 affected the motility throughout gut in fed animals. In conclusion, neither 5-HT3 nor 5-HT4 receptors tonically regulate ferret gut motility except that 5-HT3 receptors have a key role in the occurrence of migrating motor complex specifically in the stomach. The role of 5-HT3 and 5-HT4 receptor system in the regulation of gut motility in ferrets is similar to that in other mammalian species studied, including humans. This similarity suggests that the ferret is a suitable model animal to study gut motor functions in humans.