@article{oai:repo.qst.go.jp:00044320,
 author = {Zhang, Ming-Rong and Haradahira, Terushi and Maeda, Jun and Okauchi, Takashi and Kawabe, Koichi and Kida, Takayo and Obayashi, Shigeru and Suzuki, Kazutoshi and Suhara, Tetsuya and 張 明栄 and 原田平 輝志 and 前田 純 and 岡内 隆 and 大林 茂 and 鈴木 和年 and 須原 哲也},
 journal = {Nuclear Medicine and Biology},
 month = {},
 note = {3-(4-Chlorobenzyl)-8-methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one (1), a putative dopamine D4 receptor antagonist (ki = 8.7 nM), was labeled by positron-emitter (11c) and its pharmacological evaluation was carried out with in vitro quantitative autoradiography and positron emission tomography (PET). 11C-Methylation of a corresponding desmethyl precursor (2) with [11C]CH3I gave [11C]1 with >98% of radiochemical purity after HPLC purification and 67_90 GBq/mumol of specific activity at the end of synthesis. The in vitro autoradiography using rat brain sections demonstrated that [11C]1 shows no specific binding to the D4 receptors, but a high specific binding to sigma1 receptors(IC50=105nM). In the PET study with monkey brain, [11C]1 was highly taken up by the brain and trapped in the brain for at least 90 min. The distribution pattern of radioactivity in the brain was striatum > thalamus > frontal cortex > cerebellum, which was same as the result of in vitro autoradiography. Pre-treatment with non-radioactive 1 (1 mg/kg) produced a significant reduction of radioactivity in all the regions including the cerebellum. Pre-treatment with (+)pentazocine  (1 mg/kg),a selective sigma1 receptor agonist, also reduced the radioactivity in the same regions to a similar extent. These results indicate that [11C]1 may have some specific binding to the sigma1 receptors, which is consistent with the result of in vitro autoradiography.},
 pages = {469--476},
 title = {Synthesis and evaluation of 3-(4-chlorobenzyl)-8-[11C]methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one:a PET tracer for imaging sigma1 receptors},
 volume = {29},
 year = {2002}
}