Linked Life Data

9833628

Source:http://linkedlifedata.com/resource/pubmed/id/9833628

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1999-2-26
pubmed:abstractText
The effects of apomorphine on the striatal L-[11C]DOPA influx rate was examined in anaesthetized Rhesus monkeys using positron emission tomography (PET). In comparison with baseline conditions, the addition of a continuous infusion of apomorphine produced decreases in the striatal L-[11C]DOPA influx rate in all the monkeys examined. The effect of apomorphine infusion also showed a dose-dependent trend. In individual monkeys, the magnitude of the effect showed a baseline dopaminergic tone-dependency; that is, the effect of apomorphine was most pronounced in monkeys with high baseline influx rates, and in monkeys with lower baseline values apomorphine induced a weaker effect. Studies of radiolabeled tracer and radiolabeled metabolites formed in plasma confirmed that apomorphine infusion did not induce any change in the peripheral elimination or metabolite formation of L-[11C]DOPA. The decreased striatal L-[11C]DOPA influx rate induced by apomorphine was interpreted as an agonist effect on dopamine autoreceptors regulating the dopamine synthesis rate. The observation of a baseline dopaminergic tone-dependent effect is in agreement with earlier results showing this influence on the striatal influx rate as measured with the tracer L-[11C]DOPA. A priori, it can be established that L-[11C]DOPA and PET provide a method not only to study the structural integrity of the presynaptic dopaminergic system but also to study the homeostasis-regulating mechanisms of this neurotransmitter system in vivo. The ability to measure condition-dependent effects in individuals should be of great importance in determining specific pathophysiological mechanisms underlying degenerative and functional disorders affecting the dopaminergic system.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0028-3908
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
989-95
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effect of apomorphine infusion on dopamine synthesis rate relates to dopaminergic tone.
pubmed:affiliation
Uppsala University PET Centre, University Hospital, Uppsala University, Sweden.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't