PET demonstrates different behaviour of striatal dopamine D-1 and D-2 receptors in early Parkinson's disease.
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.
Rinne
J O
JO
Department of Neurology, University of Turku, Finland.
Laihinen
A
A
Någren
K
K
Bergman
J
J
Solin
O
O
Haaparanta
M
M
Ruotsalainen
U
U
Rinne
U K
UK
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
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