Dopamine receptor properties in Parkinson's disease and Huntington's chorea evaluated by positron emission tomography using 11C-N-methyl-spiperone.
Dopaminergic receptor properties in the striatum of patients with Parkinson's disease (PD) and Huntington's chorea (HD) were studied by positron emission tomography (PET), using 11C-N-methyl-spiperone as a dopamine D2 receptor ligand. The time-dependent regional radioactive uptake in the caudate nucleus and the putamen was measured and fitted to a 3-compartment pharmacokinetic model. The rate constant k3 for specific binding to the receptor compartment in the striatum was determined in relation to the binding in regions with a low density of specific binding sites, such as the cerebellum and the frontal cortex . k3, which is a measure of the receptor density, was reduced in one patient with HD but less affected in PD in comparison with healthy controls. The pattern of k3 values calculated from the 6 PD patients is discussed in relation to any side-to-side differences in dopamine receptor densities in hemiparkinsonism and to possible "hypersensitivity" of dopamine receptors in the early stage of the disease and down-regulation in more advanced disease.
D000368:Aged; D002421:Caudate Nucleus / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism*; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism; D006801:Humans; D006816:Huntington Disease / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010300:Parkinson Disease / Q000378:metabolism*; D011699:Putamen / Q000378:metabolism; D011954:Receptors, Dopamine / Q000378:metabolism*; D013134:Spiperone / Q000031:analogs & derivatives / Q000378:metabolism; D014055:Tomography, Emission-Computed
D011954:Receptors, Dopamine; D013134:Spiperone; C039167:3-N-methylspiperone