Comparison of iodine-123 labelled 2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane and 2 beta-carbomethoxy-3 beta-(4-iodophenyl)-N-(3-fluoropropyl)nortropane for imaging of the dopamine transporter in the living human brain.
Several cocaine congeners are of potential for imaging the dopamine transporter (DAT). Previous studies have shown that iodine-123 labelled 2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane ([123I] beta-CIT) is a promising radiotracer for imaging the serotonin (5-HT) and dopamine (DA) transporters in the living human brain with single-photon emission tomography (SPET). [123I] beta-CIT was found to be not very practical for 1-day DAT imaging protocols since peak DAT uptake occurs later than 8 h. Here we report a pilot comparison of [123I] beta-CIT and 2 beta-carbomethoxy-3 beta-(4-iodophenyl)-N-(3-fluoropropyl)nortropane ([123I] beta-CIT-FP), using SPET imaging in four healthy male subjects. Peak uptake of [123I] beta-CIT-FP into the basal ganglia occurred earlier (3-4 h after injection of tracer) than that of [123I] beta-CIT (> 8 h). However, the specific DAT binding of [123I] beta-CIT-FP in the basal ganglia was somewhat less (0.813 +/- 0.047) than that of [123I] beta-CIT (0.922 +/- 0.004). Imaging quality is excellent with both tracers and they are potentially of value for brain imaging in various neuropsychiatric disorders.
Kuikka
J T
JT
Department of Clinical Physiology, Kuopio University Hospital, Finland.
Bergström
K A
KA
Ahonen
A
A
Hiltunen
J
J
Haukka
J
J
Länsimies
E
E
Wang
S
S
Neumeyer
J L
JL
D001921:Brain / Q000000981:diagnostic imaging*; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000032:analysis*; D003042:Cocaine / Q000031:analogs & derivatives*; D004298:Dopamine / Q000032:analysis*; D050483:Dopamine Plasma Membrane Transport Proteins; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D010865:Pilot Projects; D011877:Radionuclide Imaging; D013997:Time Factors; D014018:Tissue Distribution; D014326:Tropanes
D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine; D004298:Dopamine