Effect of amphetamine on extrastriatal D2 dopamine receptor binding in the primate brain: a PET study.
[(11)C]raclopride binding to D2 dopamine receptors in the striatum is sensitive to drug-induced changes of endogenous dopamine concentration. We recently developed the new radioligand [(11)C]FLB 457, which is suitable for positron emission tomography (PET) studies of extrastriatal D2 dopamine receptors. The purpose of this PET study was to examine the effect of amphetamine on [(11)C]FLB 457 binding in extrastriatal regions. Each of three cynomolgus monkeys was examined at baseline conditions, 15 min and 3 h after I.V. injection of amphetamine (2 mg/kg). The effect of amphetamine was calculated from the ratio of specific [(11)C]FLB 457 binding to the binding in the cerebellum, a region which was used as reference for free and nonspecific binding in the brain. The changes of the ratio in the striatum, the thalamus, and the neocortex were between -1.2% and -15.5% at 15 min and -2.1% and -16.3% at 3 h, respectively, after amphetamine administration. The reductions of the binding ratios in the extrastriatal regions are similar to those reported for [(11)C]raclopride binding in the striatum. These data in a limited series of monkeys suggest that [(11)C]FLB 457 binding to D2 dopamine receptors in extrastriatal regions is sensitive to changes in the concentration of endogenous dopamine.
Chou
Y H
YH
Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, Stockholm, Sweden. yuanhc@psyk.ks.se
Halldin
C
C
Farde
L
L
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology*; D008252:Macaca fascicularis; D019579:Neocortex / Q000187:drug effects / Q000378:metabolism*; D011759:Pyrrolidines / Q000378:metabolism*; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism*; D012457:Salicylamides / Q000378:metabolism*; D013788:Thalamus / Q000187:drug effects / Q000378:metabolism*; D014055:Tomography, Emission-Computed
D015259:Dopamine Agents; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D012457:Salicylamides; C065065:FLB 457; D000661:Amphetamine; D004298:Dopamine