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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1997-6-16
pubmed:abstractText
Effects of (R)-N-(quinuclidin-3-yl)-2-(1-methyl-1 H-indol-3-yl)-2-oxo-acetamide (RS-056812-198) on 5-HT3 receptors have been investigated in whole-cell voltage-clamped N1E-115 mouse neuroblastoma cells and on 5-HT3 receptors composed of either long (5-HT3R-Al) or short (5-HT3R-AS) subunits expressed in Xenopus laevis oocytes. In N1E-115 cells RS-056812-198 evokes small transient inward currents, which are completely and reversibly inhibited by the selective 5-HT3 receptor antagonist MDL 72222 and cross-desensitizes with the 5-hydroxytryptamine (5-HT)-evoked current. The concentration-effect curve of RS-056812-198 yields an EC50 of 18 nM and a maximum amplitude of 15% of the maximum 5-HT-evoked current. In contrast to its effects on N1E-115 cells, RS-056812-198 does not evoke an ion current on cloned 5-HT3 receptors expressed in Xenopus oocytes, but acts as an antagonist. For 5-HT3R-A1 receptors, the IC50 of RS-056812-198 is 0.4 nM. The results show that (I) RS-056812-198 is a high-affinity partial agonist on 5-HT3 receptors in N1E-115 cells, thus providing a valuable tool to study agonist-receptor interaction in more detail: (2) 5-HT3 receptors on N1E-115 cells differ from the homo-oligomeric 5-HT3 receptors expressed in Xenopus oocytes. Whether the difference is caused by differences in protein processing in the two preparations or by expression of additional, yet unidentified subunits in N1E-115 cells and consequent formation of hetero-oligomeric 5-HT3 receptors remains to be determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
322
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
229-33
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
RS-056812-198: partial agonist on native and antagonist on cloned 5-HT3 receptors.
pubmed:affiliation
Research Institute of Toxicology, Utrecht University, Netherlands. h.vanhooft@ritox.dgk.ruu.nl
pubmed:publicationType
Journal Article