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Gastrointestinal Motility Monitor (GIMM)
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Gastrointestinal Motility Monitor (GIMM)

Published on: December 1, 2010

Chronotropic action of 5-hydroxytryptamine (5-HT) on colonic migrating motor complexes (CMMCs) in the isolated mouse

R Fida1, R A Bywater, D J Lyster

  • 1Department of Physiology, Monash University, Clayton, Australia. rose.fida@vcp.monash.edu.au

Journal of the Autonomic Nervous System
|April 1, 2000
PubMed

Insights

Serotonin (5-HT) increases the frequency of colonic motor complexes in mice. Specific receptor antagonists suggest 5-HT influences CMMC frequency, potentially via endogenous release.

Area of Science:

  • Gastroenterology
  • Neuropharmacology
  • Physiology

Background:

  • Colonic migrating motor complexes (CMMCs) are crucial for gut motility.
  • The role of serotonin (5-hydroxytryptamine, 5-HT) in regulating CMMCs is not fully understood.
  • Pie-bald lethal mouse models offer a unique system to study gastrointestinal function.

Purpose of the Study:

  • To investigate the effects of 5-hydroxytryptamine (5-HT) and its related drugs on colonic migrating motor complexes (CMMCs).
  • To determine the specific serotonin receptor subtypes involved in modulating CMMC frequency and characteristics.
  • To explore the potential involvement of endogenous 5-HT in regulating CMMC activity.

Main Methods:

  • Isolated colons from pie-bald lethal mouse heterozygotes were used.
  • The effects of various concentrations of 5-HT, 5-HT receptor agonists (5-HT2, 5-HT3, 5-HT4), and antagonists (5-HT1, 5-HT2, 5-HT3, 5-HT4) on CMMCs were assessed.
  • Changes in CMMC frequency, amplitude, and duration were measured.

Main Results:

  • 5-HT significantly increased CMMC frequency in a dose-dependent manner, without affecting amplitude or duration.
  • Specific agonists demonstrated differential effects: 5-HT2 and 5-HT3 agonists increased frequency, while the 5-HT4 agonist did not.
  • The 5-HT3 antagonist, ondansetron, increased the interval between CMMCs, while other antagonists had no significant effect alone.
  • Combined administration of 5-HT3 and 5-HT2 antagonists abolished CMMCs and diminished 5-HT's effects.

Conclusions:

  • The frequency of CMMCs in this preparation appears to be regulated by 5-hydroxytryptamine (5-HT).
  • Serotonin 5-HT3 receptors play a significant role in modulating CMMC frequency.
  • Evidence suggests that endogenously released 5-HT may influence the frequency of CMMCs.

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