@article{oai:repo.qst.go.jp:00045906,
 author = {Yanamoto, Kazuhiko and Kumata, Katsushi and Fujinaga, Masayuki and Nengaki, Nobuki and Takei, Makoto and Wakizaka, Hidekatsu and Hosoi, Rie and Momosaki, Soutarou and Yamasaki, Tomoteru and Yui, Joji and Kawamura, Kazunori and Hatori, Akiko and Inoue, Osamu and Zhang, Ming-Rong and 柳本 和彦 and 熊田 勝志 and 藤永 雅之 and 念垣 信樹 and 武井 誠 and 脇坂 秀克 and 細井 理恵 and 山崎 友照 and 由井 譲二 and 河村 和紀 and 羽鳥 晶子 and 井上 修 and 張 明栄},
 issue = {7},
 journal = {Nuclear Medicine and Biology},
 month = {Oct},
 note = {Introduction:
The translocator protein (18 kDa) (TSPO) is widely expressed in peripheral tissues, including the heart, lung, and kidney. Our laboratory developed N-benzyl-N-methyl-2-[7,8-dihydro-7-(2-[18F]fluoroethyl)-8-oxo-2-phenyl-9H-purin-9-yl]acetamide ([18F]FEDAC) as a TSPO positron emission tomography (PET) ligand. Here, using small-animal PET with [18F]FEDAC, we performed TSPO imaging and quantitative analysis of TSPO binding in rat peripheral tissues.
Methods: 
The in vivo distribution and kinetics of [18F]FEDAC were measured in rat peripheral tissues (heart, lung and kidney). Using the in vivo pseudo-equilibrium method, TSPO binding parameters [TSPO density (Bmax), dissociation constant (KD)] and receptor occupancy were estimated in these peripheral tissues.
Results: 
[18F]FEDAC was highly distributed in the lung, heart and kidney, and these TSPO-enriched tissues could be clearly visualized. The kinetics of this radioligand in these tissues was rapid, which is suitable for the determination of in vivo TSPO binding parameters and receptor occupancy. The Bmax value of TSPO in the heart, lung, and kidney was 393, 141, and 158 pmol/ml, respectively. The KD value of
the radioligand in the heart, lung, and kidney was 119, 36 and 123 nM, respectively. By pretreatment with 5 mg/kg Ro 5-4864 (a TSPO ligand), about 90% of binding sites for TSPO in the heart and lung were occupied. In the kidney, the binding sites were completely occupied by 5 mg/kg Ro 5-4864.
Conclusions:
[18F]FEDAC is a suitable PET ligand for TSPO imaging and quantitative analysis of TSPO binding in rat peripheral tissues.
The utilization of [18F]FEDAC-PET and the pseudo-equilibrium method can contribute to the study of the TSPO function and evaluate the in
vivo binding parameters and receptor occupancy of TSPO therapeutic compounds.},
 pages = {853--860},
 title = {In vivo imaging and quantitative analysis of TSPO in rat peripheral tissues using small-animal PET with [18F]FEDAC},
 volume = {37},
 year = {2010}
}