Linked Life Data

8405087

Source:http://linkedlifedata.com/resource/pubmed/id/8405087

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-10-26
pubmed:abstractText
The monoamine releasing activity of d-fenfluramine was investigated with an in vitro model consisting of synaptosomes preloaded with the 3H-neurotransmitter and extensively washed in a superfusion apparatus before a 3-min exposure to d-fenfluramine. With this model, the drug-induced release is real and is not confused by inhibition of reuptake by the drug. d-Fenfluramine (0.5 microM) induced only [3H]5-hydroxytryptamine ([3H]5-HT) release from hippocampal synaptosomes whereas 10 microM also induced some overflow from hippocampal synaptosomes preloaded with [3H]noradrenaline or from striatal synaptosomes preloaded with [3H]dopamine, although the overflow was much lower than from 5-HTergic synaptosomes. We then focused on the [3H]5-HT release induced by 0.5 microM d-fenfluramine, which was previously shown to be Ca2+ dependent. The same finding was confirmed in the present study with other experimental protocols, indicating the requirement for extracellular Ca2+ ions. By measuring [3H]5-HT uptake into rat hippocampal synaptosomes we confirmed that Ca(2+)-ions are not required for the function of the 5-HT uptake carrier or for its interaction with d-fenfluramine. d-Fenfluramine-induced [3H]5-HT release was not altered by 1 microM nitrendipine (blocking the L-type Ca2+ channels) but was slightly decreased (20%) by 0.5 microM omega-conotoxin (blocking the N-type Ca2+ channels). It was also inhibited by 0.5 microM clonidine, interacting with alpha 2-adrenergic heteroreceptors, and by 10 nM tetanus toxin, known to affect the exocytosis of different neurotransmitters including 5-HT. These compounds had very similar effects on the Ca(2+)-dependent, exocytotic release of [3H]5-HT induced by depolarization, i.e. by 15 mM K+.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
238
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9-17
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Evidence of an exocytotic-like release of [3H]5-hydroxytryptamine induced by d-fenfluramine in rat hippocampal synaptosomes.
pubmed:affiliation
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't