Mesenteric afferent sensitivity to cholecystokinin and 5-hydroxytryptamine

Dtsch Tierarztl Wochenschr. 1998 Dec;105(12):466-8.


The present electrophysiological investigation examines the effect of CCK and 5-hydroxytryptamine on gastrointestinal afferent fibre discharge. 5-HT markedly stimulated mesenteric afferents. The response was transient (< 10s) and mediated by 5-HT3 receptors as demonstrated by the action of 2-methyl-5-HT and antagonism by granisetron. CCK was also a potent stimulus to mesenteric afferents causing a long-lasting (> 30s) increase in excitability. The response to CCK was mediated via the CCKA receptor as shown by the antagonistic action of devazepide. At doses of granisetron and devazepide which completely block the response to exogenous 5-HT and CCK, the afferent fibres still responded to both mechanical and chemical stimulation of the mucosa. Thus products of enteroendocrine cells can have profound effects on mucosal afferent sensitivity but do not play an obligatory role in afferent signal transduction.

MeSH terms

  • Animals
  • Digestive System / innervation*
  • Electrophysiology / methods
  • Enteric Nervous System / drug effects
  • Enteric Nervous System / physiology*
  • Evoked Potentials / drug effects
  • Granisetron / pharmacology
  • Jejunum / innervation*
  • Nerve Fibers / drug effects
  • Nerve Fibers / physiology
  • Rats
  • Serotonin / pharmacology*
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology
  • Sincalide / pharmacology*
  • Visceral Afferents / drug effects
  • Visceral Afferents / physiology*


  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • Serotonin
  • Sincalide
  • Granisetron