title: PET demonstrates different behaviour of striatal dopamine D-1 and D-2 receptors in early Parkinson's disease.
abstract: Striatal dopamine D-1 receptor binding was investigated in vivo with positron emission tomography (PET) in five patients with early Parkinson's disease using [11C]-SCH 23390. All patients had predominantly unilateral symptoms and showed a significant reduction in the accumulation of [18F]-6-F-DOPA in the striatum contralateral to the symptoms. None of the patients had received any antiparkinsonian medication. The striatal and cerebellar radioactivity was measured and corresponding striatum/cerebellum ratios were counted. The mean striatum/cerebellum ratio of [11C]-SCH 23390 binding was symmetric between the hemispheres. By contrast, the striatum/cerebellum ratio of [11C]raclopride binding, labelling dopamine D-2 receptors, was increased significantly in the hemisphere contralateral to the symptoms as compared with the opposite hemisphere. Thus, the present results show that the behaviour of striatal D-1 and D-2 receptors is different in early Parkinson's disease.
authors.affiliation: Department of Neurology, University of Turku, Finland.
authors.forename: J O
authors.initials: JO
authors.lastname: Rinne
authors.forename: A
authors.initials: A
authors.lastname: Laihinen
authors.forename: K
authors.initials: K
authors.lastname: Någren
authors.forename: J
authors.initials: J
authors.lastname: Bergman
authors.forename: O
authors.initials: O
authors.lastname: Solin
authors.forename: M
authors.initials: M
authors.lastname: Haaparanta
authors.forename: U
authors.initials: U
authors.lastname: Ruotsalainen
authors.forename: U K
authors.initials: UK
authors.lastname: Rinne
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents; D001552:Benzazepines / Q000031:analogs & derivatives; D002250:Carbon Radioisotopes; D002531:Cerebellum / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D018492:Dopamine Antagonists; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism; D020891:Raclopride; D011954:Receptors, Dopamine / Q000378:metabolism*; D012457:Salicylamides; D014055:Tomography, Emission-Computed
chemical_list: C059321:8-chloro-2,3,4,5-tetrahydro-5-phenyl-1H-3-benzazepin-7-ol; D014150:Antipsychotic Agents; D001552:Benzazepines; D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D005462:Fluorine Radioisotopes; D011954:Receptors, Dopamine; D012457:Salicylamides; D020891:Raclopride