New rapid analysis method demonstrates differences in 6-[18F] fluoro-L-dopa plasma input curves with and without carbidopa and in hemi-MPTP lesioned monkeys.
Kinetic modeling of the PET tracer 6-[18F]fluoro-L-dopa ([18F]Dopa), used to measure presynaptic dopamine function, requires the accurate determination of the plasma input curve. We have developed a new method that uses alumina extraction preceded by cation and anion exchange resins to determine the parent compound, [18F]Dopa and its critical metabolite 3-O-methyl-6-[18F]fluoro-L-dopa. Using this method we found that carbidopa increases the plasma input of [18F]Dopa while decreasing the rate of metabolite formation, and that previous drug treatment can significantly effect [18F]Dopa metabolism.
McLellan
C A
CA
Laboratory of Cell Biology, National Institute of Mental Health, Bethesda, MD 20892.
Doudet
D J
DJ
Brücke
T
T
Aigner
T G
TG
Cohen
R M
RM
D000818:Animals; D002230:Carbidopa / Q000494:pharmacology*; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D004298:Dopamine / Q000378:metabolism; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D007839:Functional Laterality; D007700:Kinetics; D020267:MPTP Poisoning; D008253:Macaca mulatta; D012016:Reference Values; D013569:Synapses / Q000502:physiology; D013997:Time Factors
D005462:Fluorine Radioisotopes; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine; D002230:Carbidopa; D004298:Dopamine