| Autor: |
Mishina M; Department of Neuro-pathophysiological Imaging, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.; Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan., Kimura Y; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.; Department of Computational Systems Biology, Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Japan., Sakata M; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan., Ishii K; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan., Oda K; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.; Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, Sapporo, Japan., Toyohara J; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan., Kimura K; Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan., Ishiwata K; Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.; Institute of Cyclotron and Drug Discovery Research, Southern TOHOKU Research Institute for Neuroscience, Koriyama, Japan.; Department of Biofunctional Imaging, Fukushima Medical University, Fukushima, Japan. |
| Abstrakt: |
Adenosine A 1 receptors (A 1 Rs) are widely distributed throughout the entire human brain, while adenosine A 2A receptors (A 2A Rs) are present in dopamine-rich areas of the brain, such as the basal ganglia. A past study using autoradiography reported a reduced binding ability of A 1 R in the striatum of old rats. We developed positron emission tomography (PET) ligands for mapping the adenosine receptors and we successfully visualized the A 1 Rs using 8-dicyclopropylmethyl-1- 11 C-methyl-3-propylxanthine ( 11 C-MPDX). We previously reported that the density of A 1 Rs decreased with age in the human striatum, although we could not observe an age-related change in A 2A Rs. The aim of this study was to investigate the age-related change of the density of A 1 Rs in the thalamus and cerebral cortices of healthy participants using 11 C-MPDX PET. We recruited eight young (22.0 ± 1.7 years) and nine elderly healthy male volunteers (65.7 ± 8.0 years). A dynamic series of decay-corrected PET scans was performed for 60 min starting with the injection of 11 C-MPDX. We placed the circular regions of interest of 10 mm in diameter in 11 C-MPDX PET images. The values for the binding potential ( BP ND ) of 11 C-MPDX in the thalamus, and frontal, temporal, occipital, and parietal cortices were calculated using a graphical analysis, wherein the reference region was the cerebellum. BP ND of 11 C-MPDX was significantly lower in elderly participants than young participants in the thalamus, and frontal, temporal, occipital, and parietal cortices. In the human brain, we could observe the age-related decrease in the distribution of A 1 Rs. |
