[I-123]FP-CIT binding in rat brain after acute and sub-chronic administration of dopaminergic medication

The recently developed radioligand [I-123]FP-CIT is suitable for clinical s ingle-photon emission tomography (SPET) imaging of the dopamine (DA) transp orter in vivo. To date it has remained unclear whether dopaminergic medicat ion influences the striatal [I-123]FP-CIT binding. The purpose of this stud y was to investigate the influence of this medication on [I-123]FP-CIT bind ing in the brain. We used an animal model in which we administered dopamino mimetics, antipsychotics and an antidepressant. In vivo [I-123]FP-CIT bindi ng to the DA and serotonin transporters was evaluated after subchronic and acute administration of the drugs. The administered medication induced smal l changes in striatal [I-123]FP-CIT binding which were not statistically si gnificant. As expected, the DA reuptake blocker GBR 12,909 induced a signif icant decrease in [I-123]FP-CIT binding. [I-123]FP-CIT binding in the serot onin-rich hypothalamus was decreased only after acute administration of flu voxamine, The results of this study suggest that dopaminergic medication wi ll not affect the results of DA transporter SPET imaging with [I-123]FP-CIT .