| Literature DB >> 8436624 |
J O Rinne1, J Hietala, U Ruotsalainen, E Säkö, A Laihinen, K Någren, P Lehikoinen, V Oikonen, E Syvälahti.
Abstract
The effect of age on human striatal dopamine D2 receptors was investigated with positron emission tomography (PET) using [11C]raclopride as a radioligand. Twenty-one healthy volunteers aged from 20 to 81 years were studied. An equilibrium method was applied and two separate PET scans with different specific activities of [11C]raclopride were performed. The maximal number of receptors (Bmax) and their dissociation constant (Kd) were calculated using Scatchard analysis. There was an age-dependent decline in the Bmax (r = -0.49; p = 0.02) of striatal D2 receptors while the Kd remained unchanged. The results show that there is an age-related loss of striatal D2 receptors, which, together with other changes in the brain nigrostriatal dopaminergic system, may contribute to extrapyramidal symptoms associated with aging.Entities:
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Year: 1993 PMID： 8436624 DOI： 10.1038/jcbfm.1993.39
Source DB: PubMed Journal: J Cereb Blood Flow Metab ISSN： 0271-678X Impact factor: 6.200