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European Journal of Nuclear Medicine

, Volume 23, Issue 7, pp 798–803 | Cite as

Initial human studies with single-photon emission tomography using iodine-123 labelled 3-(5-cyclopropyl-1,2,4-oxadiazo-3-yl)-7-iodo-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine (NNC 13-8241)

  • Jyrki T. Kuikka
  • Jukka Hiltunen
  • Christian Foged
  • Kim A. Bergström
  • Christer Halldin
  • Kari Åkerman
  • Jari Tiihonen
  • Lars Farde
Short Communication

Abstract

The iodine-123 labelled ligand 3-(5-cyclopropyl-1,2,4-oxadiazo-3-yl)-7-iodo-5,6-dihydro-5-methyl-6oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine ([123I]NNC 13-8241) was evaluated as a probe for in vivo imaging of benzodiazepine receptor sites in the human brain. Four healthy volunteers were imaged with a high-resolution single-photon emission tomography (SPET) scanner. The metabolism of [123I]NNC 13-8241 in plasma was slow. The total brain uptake was about 1.5-fold higher than that of [123I]iomazenil. The specific binding in the cortical areas was high and less intense in the thalamus. The most intense uptake was seen in the occipital cortex. The peak cortical uptake of [123I]NNC 13-8241 was observed 6–10 h after the injection of tracer. The radiation burden to the patient was moderate, being 2.5·10−2 mSv/MBq (effective dose equivalent). A slow metabolism together with favourable kinetics indicates that [123I]NNC 13-8241 is a specific and promising SPET ligand for imaging benzodiazepine receptor sites in the living human brain.

Key words

Benzodiazepine Dynamic single-photon emission tomography Iodine-123-3-(5-cyclopropyl1,2,4-oxadiazo-3-yl)-7-iodo-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine Receptors NNC 13-8241 

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Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Jyrki T. Kuikka
    • 1
  • Jukka Hiltunen
    • 2
  • Christian Foged
    • 3
  • Kim A. Bergström
    • 1
    • 4
  • Christer Halldin
    • 4
  • Kari Åkerman
    • 1
  • Jari Tiihonen
    • 5
  • Lars Farde
    • 4
  1. 1.Department of Clinical PhysiologyKuopio University HospitalKuopioFinland
  2. 2.MAP Medical Technologies OyTikkakoskiFinland
  3. 3.NOVO Nordisk A/SMaalovDenmark
  4. 4.Department of Clinical Neuroscience, Psychiatry SectionKarolinska InstituteStockholmSweden
  5. 5.Niuvaniemi HospitalKuopioFinland

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