Linked Life Data

11128040

Source:http://linkedlifedata.com/resource/pubmed/id/11128040

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-12-20
pubmed:abstractText
The effect of an endogenous 5-hydroxytryptamine (5-HT) precursor, 5-hydroxytryptophan (5-HTP), on the luminal outflow of 5-HT was examined using the luminally perfused isolated colon of the guinea pig, a model that would facilitate the pharmacological analysis of luminal 5-HT release from enterochromaffin cells (EC cells). 5-HTP (1-10 microM) concentration-dependently caused an increase of the luminal outflow of 5-HT. Either tetrodotoxin (0.3 microM) or atropine (0.2 microM) did not affect the 5-HTP-evoked increase in luminal 5-HT outflow, while the L-type calcium channel blocker, nicardipine (1 microM) or diltiazem (1 microM) reduced the 5-HTP-evoked 5-HT outflow by 47% and 61%, respectively. SB203186 (1 microM), a 5-HT4-receptor antagonist, enhanced the 5-HTP-evoked 5-HT outflow, while ramosetron (1 microM), a 5-HT3-receptor antagonist reduced the stimulating effect of 5-HTP by 66%. Ketanserin (0.1 microM), a 5-HT2A-receptor antagonist did not modify the stimulatory effect of 5-HTP. It is concluded that in the guinea pig colon, 5-HTP facilitates the luminal 5-HT release from EC cells, with no involvement of neuronal mechanisms and a non-neuronal cholinergic system. Furthermore, non-neuronal 5-HT3 and 5-HT4 receptors appear to contribute to the regulation of the luminal 5-HT release evoked by 5-HTP. This new bioassay of the guinea pig colon allows the pharmacological characterization of uncomplicated luminal 5-HT release from EC cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-5198
pubmed:author
pubmed:issnType
Print
pubmed:volume
84
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
174-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Investigation into the 5-hydroxytryptophan-evoked luminal 5-hydroxytryptamine release from the guinea pig colon.
pubmed:affiliation
Department of Pharmacology, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. s-kojima@dokkyomed.ac.jp
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't