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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4-5
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pubmed:dateCreated |
1997-9-15
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pubmed:abstractText |
Potentiation of the 5-HT3 receptor-mediated ion current in mouse N1E-115 neuroblastoma cells by 5-hydroxyindole (5-OHi) and three analogues (5-aminoindole, catechol and indole) was examined using whole-cell voltage clamp and single channel patch clamp techniques. The substances tested enhanced the amplitude of the maximum 5-HT-evoked ion current by 12-30%. The rank order (at 1 mM) to potentiate the 5-HT-induced current was: 5-OHi approximately 5-aminoindole approximately catechol > indole. The concentration-effect curve of 5-HT was shifted leftwards by 1 mM 5-OHi, resulting in a two-fold increase of the apparent affinity of 5-HT from 1.4 microM to 0.7 microM, without affecting the Hill coefficient. The time constant of reversal of activation of the 5-HT-induced ion current upon washout of the agonist was delayed by 1 mM 5-OHi from 4.0 sec to 12.8 sec. 5-HT3 receptor-gated single channel events in cell-attached patches in the presence and absence of 1 mM 5-OHi were indistinguishable, apart from a slight increase in the event frequency. The results suggest that 5-OHi and analogues potentiate the 5-HT3 receptor-mediated ion current by delaying agonist dissociation and thereby increase the probability of channel opening. From the increased apparent affinity of 5-HT and the non-surmountability of the potentiating effect, it is concluded that 5-OHi and analogues are allosteric modulators of 5-HT3 receptors.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/5-hydroxyindole,
http://linkedlifedata.com/resource/pubmed/chemical/Catechols,
http://linkedlifedata.com/resource/pubmed/chemical/Indoles,
http://linkedlifedata.com/resource/pubmed/chemical/Ion Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Serotonin,
http://linkedlifedata.com/resource/pubmed/chemical/catechol,
http://linkedlifedata.com/resource/pubmed/chemical/indole
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pubmed:status |
MEDLINE
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pubmed:issn |
0028-3908
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
36
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
649-53
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:9225290-Animals,
pubmed-meshheading:9225290-Brain Neoplasms,
pubmed-meshheading:9225290-Catechols,
pubmed-meshheading:9225290-Indoles,
pubmed-meshheading:9225290-Ion Channels,
pubmed-meshheading:9225290-Membrane Potentials,
pubmed-meshheading:9225290-Mice,
pubmed-meshheading:9225290-Neuroblastoma,
pubmed-meshheading:9225290-Patch-Clamp Techniques,
pubmed-meshheading:9225290-Receptors, Serotonin,
pubmed-meshheading:9225290-Tumor Cells, Cultured
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pubmed:articleTitle |
Allosteric potentiation of the 5-HT3 receptor-mediated ion current in N1E-115 neuroblastoma cells by 5-hydroxyindole and analogues.
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pubmed:affiliation |
Research Institute of Toxicology, Utrecht University, The Netherlands.
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pubmed:publicationType |
Journal Article
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