Linked Life Data

19573609

Source:http://linkedlifedata.com/resource/pubmed/id/19573609

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-8-24
pubmed:abstractText
[11C]MePPEP is a high affinity, CB1 receptor-selective, inverse agonist that has been studied in rodents and monkeys. We examined the ability of [11C]MePPEP to quantify CB1 receptors in human brain as distribution volume calculated with the "gold standard" method of compartmental modeling and compared results with the simple measure of brain uptake. A total of 17 healthy subjects participated in 26 positron emission tomography (PET) scans, with 8 having two PET scans to assess retest variability. After injection of [11C]MePPEP, brain uptake of radioactivity was high (e.g., 3.6 SUV in putamen at approximately 60 min) and washed out very slowly. A two-tissue compartment model yielded values of distribution volume (which is proportional to receptor density) that were both well identified (SE 5%) and stable between 60 and 210 min. The simple measure of brain uptake (average concentration of radioactivity between 40 and 80 min) had good retest variability ( approximately 8%) and moderate intersubject variability (16%, coefficient of variation). In contrast, distribution volume had two-fold greater retest variability ( approximately 15%) and, thus, less precision. In addition, distribution volume had three-fold greater intersubject variability ( approximately 52%). The decreased precision of distribution volume compared to brain uptake was likely due to the slow washout of radioactivity from brain and to noise in measurements of the low concentrations of [11C]MePPEP in plasma. These results suggest that brain uptake can be used for within subject studies (e.g., to measure receptor occupancy by medications) but that distribution volume remains the gold standard for accurate measurements between groups.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1095-9572
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
362-70
pubmed:dateRevised
2010-12-3
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Quantitation of cannabinoid CB1 receptors in healthy human brain using positron emission tomography and an inverse agonist radioligand.
pubmed:affiliation
Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural