PET imaging of dopamine receptors in MPTP-induced parkinsonism

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:7087630

Larson, S M; DiChiro, G; Burns, R S; Dannals, R F; Kopin, I J; Brooks, R A; Kessler, R M; Wagner, R F; Eckelman, W C; Margolin, R A

MPTP(N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) induces parkinsonism in animals and man by selectively destroying dopaminergic neurons in the pars compacta of the substantia nigra. The postsynaptic neurons (and presumably the dopamine receptors) are intact. The authors have imaged dopamine receptors in a patient with MPTP induced parkinsonism, using /sup 11/CMS (3-N(/sup 11/C) methylspiperone. Seven and 9 mCi's, respectively, were injected at one week intervals while the patient was first off, and then on, L-dopa. As measured by NeuroPET (NIH), putamen to cerebellum concentration ratios rose progressively to 5.5:1, by 90 min. after injection. At this time the concentration of /sup 11/CMS was 10 picomole/cc (off L-dopa), and 14 picomole/cc (on L-dopa). The Duvoisin scale was used to assess the severity of the patient's parkinsonism immediately prior and at the end of PET imaging. On both occasions, despite the small mass amount of /sup 11/CMS injected, (1.1 g/kg), a transient worsening of symptoms was seen. The effect of L-Dopa was almost completely reversed by the /sup 11/CMS. In contrast, off L-Dopa the patients severe basal state was worsened only slightly. The PET scans suggested that dopamine receptors are not reduced in MPTP-induced parkinsonism. The findings were consistent with the hypotheses that PET may identify patients who will benefit from L-Dopa, and that expression of parkinsonian symptoms reflects desaturation of dopamine receptors in striatum.

• Research Organization: NIH Bethesda, Baltimore, MD
• OSTI ID: 7087630
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
AMINO ACIDS
ANIMAL CELLS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
BASAL METABOLISM
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
BRAIN
CARBON 11
CARBON ISOTOPES
CARBOXYLIC ACIDS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
CEREBELLUM
COMPUTERIZED TOMOGRAPHY
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DIAGNOSTIC USES
DISEASES
DOPA
DOPAMINE
DRUGS
EMISSION COMPUTED TOMOGRAPHY
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
HYDROXY COMPOUNDS
IMAGE PROCESSING
INJECTION
INTAKE
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MEMBRANE PROTEINS
METABOLISM
MINUTES LIVING RADIOISOTOPES
NERVE CELLS
NERVOUS SYSTEM
NERVOUS SYSTEM DISEASES
NEUROREGULATORS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PATIENTS
PHENOLS
POLYPHENOLS
POSITRON COMPUTED TOMOGRAPHY
PROCESSING
PROTEINS
PYRIDINES
QUANTITY RATIO
RADIOISOTOPES
RECEPTORS
SOMATIC CELLS
SYMPATHOMIMETICS
SYMPTOMS
TOMOGRAPHY
USES