title: Synthesis of 6-[(11)C]methyl-m-tyrosine ([(11)C]6MemTyr) for dopamine synthesis imaging in living brain using PET.
abstract: A novel PET probe, 6-[(11)C]methyl-m-tyrosine ([(11)C]6MemTyr), was developed for quantitative imaging of presynaptic dopamine (DA) synthesis in the living brain using positron emission tomography (PET). This probe was evaluated by comparison with conventional 6-[(18)F]fluoro-l-dopa ([(18)F]FDOPA). [(11)C]6MemTyr was labeled using rapid Pd(0)-mediated C-[(11)C]methylation with [(11)C]methyl iodide. The synthesis time was only 35min, and its radiochemical yield was 76%, with radiochemical purity of >99%. PET measurements indicated that [(11)C]6MemTyr could image presynaptic DA synthesis in the striatum of living monkey brain, providing much higher contrast between the striatum and the cerebellum than that with [(18)F]FDOPA.
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Kanazawa
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohba
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Iwazaki
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Kakiuchi
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka 434-8601, Japan. Electronic address: tsukada@crl.hpk.co.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsukada
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000032:analysis* / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism; D004298:Dopamine / Q000032:analysis* / Q000378:metabolism; D005462:Fluorine Radioisotopes / Q000032:analysis / Q000378:metabolism; D007980:Levodopa / Q000032:analysis; D008252:Macaca fascicularis; D008297:Male; D008781:Methyltyrosines / Q000032:analysis* / Q000138:chemical synthesis / Q000378:metabolism; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000032:analysis / Q000138:chemical synthesis / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D008781:Methyltyrosines; D019275:Radiopharmaceuticals; C032745:methyl-3-tyrosine; D007980:Levodopa; D004298:Dopamine
keywords: 6-[(11)C]methyl-m-tyrosine; Brain; Dopamine; PET; [(18)F]FDOPA