5-Methoxytryptamine and 2-methyl-5-hydroxytryptamine-induced desensitization as a discriminative tool for the 5-HT3 and putative 5-HT4 receptors in guinea pig ileum

@article{Craig20045MethoxytryptamineA2,
  title={5-Methoxytryptamine and 2-methyl-5-hydroxytryptamine-induced desensitization as a discriminative tool for the 5-HT3 and putative 5-HT4 receptors in guinea pig ileum},
  author={Douglas A Craig and R. M. Eglen and L. K. M. Walsh and L. A. Perkins and Roger Lewis Whiting and David E. Clarke},
  journal={Naunyn-Schmiedeberg's Archives of Pharmacology},
  year={2004},
  volume={342},
  pages={9-16}
}
  • D. Craig, R. Eglen, D. Clarke
  • Published 1 July 1990
  • Biology, Chemistry
  • Naunyn-Schmiedeberg's Archives of Pharmacology
SummaryAgonist-induced desensitization has been utilized to discriminate and independently “isolate” the neuronal excitatory receptors to 5-hydroxytryptamine (5-HT) in the guinea pig ileum (5-HT3 and putative 5-HT4 receptors). Electrically stimulated longitudinal muscle myenteric plexus preparations, and non-stimulated segments of whole ileum were used. Exposure to 5-methoxytryptamine (10 μmol/l) inhibited completely responses to 5-HT at the putative 5-HT4 receptor without affecting 5-HT3… 
fnvolves Several 5-HydroxytryptarnincRecept6r Subtypes
TLDR
5-HT-induced jejunal secretion involves more than one 5-HT receptor subtype, with both neural and non-neural mechanisms contributing to the response.
SDZ 205-557, a selective, surmountable antagonist for 5-HT4 receptors in the isolated guinea pig ileum
TLDR
It is concluded that SDZ 205-557 is a potent, selective and surmountable antagonist at 5- HT4 receptors in the isolated guinea pig ileum, and is a more practical tool for the characterization of 5-HT4 receptors than ICS 205-930.
Changes in sensitivity of 5-HT receptor mediated functional responses in the rat oesophagus, fundus and jejunum following chronic infusion with 5-hydroxytryptamine
TLDR
It is shown in a preliminary characterisation that in rat jejunum, 5-HT produces a biphasic concentration-effect curve which is mediated by a putative 5-ht7/5-HT3 receptor-mediated responses in rat oesophagus, fundus andJejunum respectively when measured in vitro.
Effects of 5-HT4 receptor stimulation on basal and electrically evoked release of acetylcholine from guinea-pig myenteric plexus
TLDR
5-methoxytryptamine may both inhibit (via 5-HT1 receptors) and facilitate (via5-HT4 receptors) the evoked release of acetylcholine from guinea-pig myenteric neurones and the facilitatory action is unmasked when the 5- HT1 receptor is blocked by methiothepine.
5-Hydroxytryptamine (5-HT) Cellular Sequestration during Chronic Exposure Delays 5-HT3 Receptor Resensitization due to Its Subsequent Release*
TLDR
The findings suggest the existence of a novel mechanism of down-regulation where the chronic release of sequestered 5-HT prolongs receptor desensitization in the guinea pig ileum.
5-Hydroxytryptamine4 receptors mediate relaxation of the rat oesophageal tunica muscularis mucosae
TLDR
Concentration-effect curves to 5-HT were not affected by tetrodotoxin or indomethacin, sugesting that 5- HT-induced relaxation of the tunica muscularis mucosae was mediated via a postjunctional receptor, independent of endogenous prostanoids.
Cisapride and a structural analogue, R 76186, are 5-hydroxytryptamine4 (5-HT4) receptor agonists on the guinea-pig colon ascendens
TLDR
Both cisapride and R 76186 mediate their contractile effects in the guinea-pig colon ascendens through agonism at the 5-HT4 receptor, though cisap Ride also uses a non-5-HT mechanism.
Comparison of 5-HT4 receptors in guinea-pig colon and rat oesophagus: effects of novel agonists and antagonists
Abstract5-HT4 receptors in isolated distal colon myenteric plexus of guinea-pig, mediating contraction of longitudinal smooth muscle, have been further characterized by selective agonists and
Investigation of the 5-hydroxytryptamine receptor mediating the “transient” short-circuit current response in guinea-pig ileal mucosa
TLDR
The data show that neuronal and non-neuronal 5-HT receptors are involved in the regulation of secretion in ileal mucosa, and propose the presence of a neuronal 5- HT4 receptor located upstream of the well characterized neuronal 3-methyl-5-hydroxytryptamine receptors to be responsible for the high potency5-HT response.
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