The influence of neuronal 5-hydroxytryptamine receptor antagonists on non-cholinergic ganglionic transmission in the guinea-pig enteric excitatory reflex

M. Tonini, T. Coccini, L. Onori, S. M. Candura, C. A. Rizzi, L. Manzo

Research output: Contribution to journalArticlepeer-review

Abstract

A partitioned bath made it possible to separate the site of recording of the ascending excitatory reflex of the ileal circular muscle (oral compartment) from the site of reflex induction (caudal compartment), evoked by inflating an intraluminal balloon. In the caudal compartment, blockade of cholinergic ganglionic transmission by hexamethonium (100 μM) and hyoscine (0.3 μM) caused an approximately 65% reduction in the amplitude of reflex contractions, suggesting that the remaining response was mediated by non-cholinergic transmission near the distension site. This non-cholinergic component of ganglionic transmission was insensitive to the action of methiothepin (1 μM), ondansetron (1 μM), tropisetron (1.5 μM), DAU 6285 (1 μM) and renzapride (1 μM), agents that antagonize the action of 5-hydroxytryptamine (5-HT) at neural 5-HT1-like, 5-HT3, 5-HT4 and putative 5-HT(1P) receptors. These findings suggest that the neural pathways subserving non-cholinergic ganglionic transmission in the ascending excitatory reflex in the guinea-pig ileum do not involve 5-HT as neurotransmitter.

Original languageEnglish
Pages (from-to)5-7
Number of pages3
JournalBritish Journal of Pharmacology
Volume107
Issue number1
Publication statusPublished - 1992

Keywords

  • 5-HT receptor antagonists
  • 5-Hydroxytryptamine (5-HT)
  • Ascending excitatory reflex
  • Isolated small intestine
  • Non-cholinergic ganglionic transmission

ASJC Scopus subject areas

  • Pharmacology

Fingerprint Dive into the research topics of 'The influence of neuronal 5-hydroxytryptamine receptor antagonists on non-cholinergic ganglionic transmission in the guinea-pig enteric excitatory reflex'. Together they form a unique fingerprint.

Cite this