Synthesis and biodistribution of [11C]fludiazepam for imaging benzodiazepine receptors

Kiichi Ishiwata, Kazuhiko Yanai, Tatsuo Ido, Yuko Miura-Kanno, Koichiro Kawashima

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


As a tracer for in vivo studies on benzodiazepine receptors, 7-chloro-1,3-dihydro-5-(2-fluorophenyl)-1-[11C]methyl-2H-1, 4-benzodiazepin-2-one, [11C]fludiazepam, was synthesized by the methylation of norderivative with [11C]CH3I, and purified by high-performance liquid chromatography. Within 60 min [11C]fludiazepam was obtained for injection in high radiochemical yields and in high radiochemical purity with a specific activity of up to 230mCi/μmol. After i.v. injection of [11C]fludiazepam in rats the radioactivity was rapidly incorporated into many tissues and the blood clearance of the radioactivity was very rapid. The brain uptake was high and decreased gradually. The adrenal uptake was the highest and decreased with high loading doses. The effect of the loading dose on the uptake was also found in the heart and lungs. By autoradiography using [11C]fludiazepam, a higher accumulation was visualized in the cortex and thalamus than in other regions.

Original languageEnglish
Pages (from-to)365-369,371
JournalInternational Journal of Radiation Applications and Instrumentation.
Issue number4
Publication statusPublished - 1988

ASJC Scopus subject areas

  • Medicine(all)


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