Biodistribution, dosimetry, metabolism and monkey PET studies of [18F]GBR 13119. Imaging the dopamine uptake system in vivo.

The in vivo characteristics of a new radiotracer, [18F]GBR 13119, have been examined. Full body biodistribution in rats has been determined and the expected human dosimetry calculated. Pharmacological specificity of in vivo regional brain distribution in rats was examined. Blockage of specific binding was accomplished by dopamine reuptake inhibitors but no effect was observed for pretreatment with serotonin or norepinephrine reuptake inhibitors. Preliminary examination of rat blood shows the presence of radiolabeled metabolites, which can be rapidly identified using bonded-phase (Sep-Pak) chromatography. Finally, the striatum of living primates has been imaged using PET and i.v. administration of [18F]GBR 13119. These results represent the intermediate steps in the development of [18F]GBR 13119 as a radiotracer for the study of the dopamine uptake system in man.