title: Metabolites of 6-[18F]fluoro-L-dopa in human blood.
abstract: The metabolites of 6-[18F]fluoro-L-dopa in the blood plasma of healthy humans have been identified as 3-O-sulfato-6[18F]fluoro-L-dopa, 3-O-methyl-6-[18F]fluoro-L-dopa, 6-[18F] fluorodopamine, and 6-[18F]fluorohomovanillic acid. The time course of these metabolites was followed up to 2 hr. The findings have implications for the use of 6-[18F]fluoro-L-dopa as tracer for cerebral dopamine metabolism. Despite the variety of metabolites in the peripheral blood there are only two 18F-carrying compounds, 6-[18F]fluoro-L-dopa and 3-O-methyl-6-[18F]fluoro-L-dopa, that can cross the blood-brain barrier. After 1 hr, the plasma concentration of 3-O-methyl-6-[18F]fluoro-L-dopa reaches approximately 20% that of 6-[18F]fluoro-L-dopa but the mean concentration of the O-methylated metabolite over the same interval is less than 5% that of 6-[18F]-fluoro-L-dopa.
mesh_terms: D000328:Adult; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000097:blood; D004298:Dopamine / Q000031:analogs & derivatives / Q000097:blood; D005462:Fluorine Radioisotopes; D006719:Homovanillic Acid / Q000097:blood; D006801:Humans; D008875:Middle Aged
chemical_list: D005462:Fluorine Radioisotopes; C055151:3-O-methyl-6-fluoro-dopa; C055153:6-fluorohomovanillic acid; C055098:3-O-sulfato-6-fluoro-dopa; C043437:fluorodopa F 18; C029253:6-fluorodopamine; D004295:Dihydroxyphenylalanine; D004298:Dopamine; D006719:Homovanillic Acid