Noradrenaline stimulates 5-hydroxytryptamine release from mouse ileal tissues via alpha(2)-adrenoceptors

Eur J Pharmacol. 2001 Dec 7;432(2-3):149-52. doi: 10.1016/s0014-2999(01)01474-1.

Abstract

The effect of noradrenaline on 5-hydroxytryptamine (5-HT) release from isolated mouse ileal tissues was investigated. Noradrenaline, but not isoprenaline, at 1 microM stimulated 5-HT release, an effect which was inhibited by yohimbine, an alpha(2)-adrenoceptor antagonist, but not by bunazosin, an alpha(1)-adrenoceptor antagonist. alpha(2)-Adrenoceptor agonists, UK 14,304 (5-bromo-6-(2-imidazolin-2-yl-amino)-quinoxaline) and clonidine at a higher concentration (10 microM) also stimulated 5-HT release, while alpha(1)-adrenoceptor agonists, methoxamine and phenylephrine, had no effect. The effect of noradrenaline was completely abolished in ileal tissues isolated from mouse treated with pertussis toxin (100 microg/kg, i.v.) for 2 days. These results suggest that noradrenaline causes 5-HT release from enterochromaffin cells in mouse ileal tissues via alpha(2)-adrenoceptor subtypes coupled to a pertussis toxin-sensitive G protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-2 Receptor Agonists
  • Adrenergic alpha-2 Receptor Antagonists
  • Adrenergic alpha-Agonists / pharmacology
  • Adrenergic alpha-Antagonists / pharmacology
  • Animals
  • Brimonidine Tartrate
  • Clonidine / pharmacology
  • Ileum / drug effects*
  • Ileum / metabolism
  • In Vitro Techniques
  • Male
  • Methoxamine / pharmacology
  • Mice
  • Mice, Inbred ICR
  • Norepinephrine / pharmacology*
  • Pertussis Toxin
  • Phenylephrine / pharmacology
  • Quinazolines / pharmacology
  • Quinoxalines / pharmacology
  • Receptors, Adrenergic, alpha-2 / physiology*
  • Serotonin / metabolism*
  • Virulence Factors, Bordetella / pharmacology
  • Yohimbine / pharmacology

Substances

  • Adrenergic alpha-2 Receptor Agonists
  • Adrenergic alpha-2 Receptor Antagonists
  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Quinazolines
  • Quinoxalines
  • Receptors, Adrenergic, alpha-2
  • Virulence Factors, Bordetella
  • Phenylephrine
  • Yohimbine
  • Serotonin
  • Brimonidine Tartrate
  • bunazosin
  • Pertussis Toxin
  • Methoxamine
  • Clonidine
  • Norepinephrine