Linked Life Data

3512770

Source:http://linkedlifedata.com/resource/pubmed/id/3512770

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-4-2
pubmed:abstractText
Isolated rat neurointermediate lobes were incubated in vitro. The release of 3,4-dihydroxyphenylethylamine (dopamine, DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and methoxyphenylethanol (MOPET) was determined by HPLC with electrochemical detection. Under resting conditions, the outflow of metabolites was 35-50 times that of DA. HVA accounted for 50%, DOPAC for 45%, and MOPET for 5% of the metabolites. Although an equivalent of 40-50% of the tissue DA content was released per hour as metabolites, the tissue DA content was not reduced after 110 min of incubation. The spontaneous outflow of DA and its metabolites was not affected by the DA uptake inhibitor GBR 12921 (100 nM). Pargyline (10 microM) caused a time-dependent decrease of all metabolites (up to 90%). In the presence of GBR 12921 and pargyline, the spontaneous outflow of DA increased sevenfold. Removal of the intermediate lobe caused a 78% reduction in tissue DA content and a corresponding reduction of the outflow of metabolites. Electrical stimulation of the pituitary stalk (0.2 ms, 10 V, 15 Hz, three times for 1 min at intervals of 1 min) induced an increase in outflow of DA and all metabolites. DA accounted for 15%, HVA for 41%, DOPAC for 32%, and MOPET for 12% of the evoked release. The electrically evoked release of DA increased fourfold in the presence of GBR 12921 or pargyline and the effects of both drugs were additive. The evoked release of metabolites was not significantly affected by GBR 12921 but completely abolished by pargyline. In conclusion, oxidative deamination and O-methylation are important pathways for the catabolism of DA in the neurointermediate lobe.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-3042
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
745-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Release of endogenous 3,4-dihydroxyphenylethylamine and its metabolites from the isolated neurointermediate lobe of the rat pituitary gland. Effects of electrical stimulation and of inhibition of monoamine oxidase and reuptake.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't