STRIATAL F-18 DOPA UPTAKE - ABSENCE OF AN AGING EFFECT

L-[F-18]6-Fluoro-DOPA (L-[F-18]6-fluoro-3,4-dihydroxyphenylalanine; FD OPA) has been used with quantitative positron emission tomography (PET ) to assess presynaptic nigrostriatal dopaminergic function in life. T he relationship of estimated kinetic rate constants for striatal FDOPA uptake [K(i)(FDOPA)] to the normal aging process has been the subject of conflicting reports. Resolution of this issue has been hampered by methodological differences in previous FDOPA/PET investigations. We s tudied 19 healthy normal subjects (aged 27-77 years) and measured stri atal K(i)-(FDOPA) according to each of the earlier methods. While sign ificant correlations (p < 0.005) existed between K(i)(FDOPA) values es timated by the various techniques, none correlated with normal aging. We conclude that normal striatal K(i)(FDOPA) values estimated using qu antitative FDOPA/PET are uncorrelated with the aging process.