Quantification of [(123)I]PE2I binding to dopamine transporters with SPET.
The iodinated cocaine derivative [(123)I]PE2I is a new selective ligand for in vivo studies of the dopamine transporter (DAT) with single-photon emission tomography (SPET). The aim of the present study was to describe a method for accurate quantification of binding data following a bolus injection of [(123)I]PE2I. Six healthy subjects (age 51+/-24 years) underwent xenon-133 SPET for quantification of regional CBF and [(123)I]PE2I SPET for quantification of DAT binding. rCBFs were within normal limits in all subjects. Fitting data to a two-tissue compartment model resulted in striatal K(1) values of 0.39+/-0.08 ml ml(-1) min(-1), equal to a first-pass extraction fraction of 0.72+/-0.13. Distribution volumes (DVs) were calculated using compartment analysis, area under the curve analysis and Logan analysis. Logan analysis is preferred since stable DV values were already obtained 120 min after [(123)I]PE2I injection. Mean striatal DV was 37.9+/-9.6 ml ml(-1) and mean occipital cortex DV was 5.5+/-0.7 ml ml(-1). In the absence of local pathology in a reference tissue, Logan analysis without blood sampling is an attractive method for accurate quantification of striatal [(123)I]PE2I binding. The distribution volume ratio (DVR) (6.6+/-1.4) was in good agreement with the DVR calculated with blood (6.7+/-1.4).
Pinborg
Lars H
LH
Neurobiology Research Unit, University Hospital Rigshospitalet, N9201, 9 Blegdamsvej, 2100 Copenhagen, Denmark. pinborg@pet.rh.dk
Videbaek
Charlotte
C
Svarer
Claus
C
Yndgaard
Stig
S
Paulson
Olaf B
OB
Knudsen
Gitte M
GM
D019540:Area Under Curve; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism*; D002560:Cerebrovascular Circulation; D003342:Corpus Striatum / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D006801:Humans; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D008954:Models, Biological; D008956:Models, Chemical; D009419:Nerve Tissue Proteins; D009662:Nortropanes / Q000493:pharmacokinetics*; D019047:Phantoms, Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon; D014980:Xenon Radioisotopes / Q000493:pharmacokinetics
D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; C113010:N-(3-iodoprop-2-enyl)-2-beta-carbomethoxy-3-(4-methylphenyl)nortropane; D009419:Nerve Tissue Proteins; D009662:Nortropanes; D019275:Radiopharmaceuticals; C493214:SLC6A3 protein, human; D014980:Xenon Radioisotopes