Linked Life Data

16416444

Source:http://linkedlifedata.com/resource/pubmed/id/16416444

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-1-24
pubmed:abstractText
PET measurements of stimulant-induced dopamine (DA) release are typically performed with antagonist radioligands that bind to both the high- and low-affinity state of the receptor. In contrast, an agonist radioligand binds preferentially to the high-affinity state and is expected to have greater sensitivity to DA, which is the endogenous agonist. [(11)C]MNPA, (R)-2-CH(3)O-N-n-propylnorapomorphine (MNPA), is a D(2) agonist radioligand with subnanomolar affinity to the D(2) receptor. The aim of the present study is to assess and compare the sensitivity of the agonist radioligand [(11)C]MNPA and antagonist radioligand [(11)C]raclopride to synaptic DA levels. Four cynomolgus monkeys were examined with [(11)C]MNPA and [(11)C]raclopride (16 PET measurements with each tracer) at baseline and after pretreatment with various doses of amphetamine. The effect of amphetamine was calculated by the change in binding potential (BP) analyzed with the multilinear reference tissue model (MRTM2). Amphetamine caused a reduction in [(11)C]MNPA BP of 4% at 0.1, 23% at 0.2, 25% at 0.5, and 46% at 1.0 mg/kg. [(11)C]Raclopride BP was reduced to a lesser extent by 2% at 0.1, 16% at 0.2, 15% at 0.5, and 23% at 1.0 mg/kg. The data were used to estimate the in vivo percentage of high-affinity state receptors to be approximately 60%. These results demonstrate that [(11)C]MNPA is more sensitive than [(11)C]raclopride to displacement by endogenous DA, and that it may provide additional information about the functional state of the D(2) receptor in illnesses such as schizophrenia and Parkinson's disease.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0887-4476
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
260-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16416444-Amphetamine, pubmed-meshheading:16416444-Animals, pubmed-meshheading:16416444-Binding, Competitive, pubmed-meshheading:16416444-Brain, pubmed-meshheading:16416444-Brain Chemistry, pubmed-meshheading:16416444-Dopamine Agonists, pubmed-meshheading:16416444-Dopamine Antagonists, pubmed-meshheading:16416444-Dopamine Uptake Inhibitors, pubmed-meshheading:16416444-Dose-Response Relationship, Drug, pubmed-meshheading:16416444-Macaca fascicularis, pubmed-meshheading:16416444-Naproxen, pubmed-meshheading:16416444-Positron-Emission Tomography, pubmed-meshheading:16416444-Protein Binding, pubmed-meshheading:16416444-Raclopride, pubmed-meshheading:16416444-Radiopharmaceuticals, pubmed-meshheading:16416444-Receptors, Dopamine D2, pubmed-meshheading:16416444-Time Factors, pubmed-meshheading:16416444-Tissue Distribution
pubmed:year
2006
pubmed:articleTitle
Effect of amphetamine on dopamine D2 receptor binding in nonhuman primate brain: a comparison of the agonist radioligand [11C]MNPA and antagonist [11C]raclopride.
pubmed:affiliation
Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institutet, Karolinska Hospital, S-17176 Stockholm, Sweden. Nick.Seneca@cns.ki.se
pubmed:publicationType
Journal Article, Comparative Study, Research Support, N.I.H., Intramural