Distribution kinetics of 18F-DOPA in weaver mutant mice.

Distribution kinetics of 18F-fluoro-dihydroxy phenylalanine (18F-DOPA) were studied with high-resolution micro-positron emission tomography (microPET) imaging and conventional methods in control wild-type mice, heterozygous weaver mutant mice, and homozygous weaver mutant mice. 18F-DOPA uptake was significantly increased in the CNS within 60 min in all the genotypes examined. Homozygous weaver mutant mice exhibited significantly reduced 18F-DOPA uptake in the region of interest (striatum) as compared to heterozygous weaver mutant mice and control wild-type mice. 18F-DOPA was de-localized in the kidneys of homozygous weaver mutant mice. The radioactivity was localized primarily in the liver and kidneys within 2 h and in the urinary bladder within 4 h. After 8 h, it could be detected neither by conventional nor by microPET imaging. Distribution kinetics of 18F-DOPA with microPET imaging correlated and confirmed the conventional observations. These data are interpreted to suggest that microPET imaging may provide an efficient, noninvasive, cost-effective procedure to study distribution kinetics of PET radiopharmaceuticals in rare genetically altered animals. Furthermore, this unique and noninvasive approach may expedite quality control and drug development for human applications.