Psychopharmacology

, Volume 210, Issue 3, pp 331–336

Norepinephrine transporter occupancy by antidepressant in human brain using positron emission tomography with (S,S)-[18F]FMeNER-D2

Authors

  • Mizuho Sekine
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
    • Department of NeuropsychiatryNippon Medical School
  • Ryosuke Arakawa
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
    • Department of NeuropsychiatryNippon Medical School
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
  • Masaki Okumura
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
    • Department of NeuropsychiatryNippon Medical School
  • Takeshi Sasaki
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
  • Hidehiko Takahashi
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
  • Harumasa Takano
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
  • Yoshiro Okubo
    • Department of NeuropsychiatryNippon Medical School
  • Christer Halldin
    • Department of Clinical NeurosciencePsychiatry Section, Karolinska Institutet, Karolinska Hospital
  • Tetsuya Suhara
    • Molecular Neuroimaging Group, Molecular Imaging CenterNational Institute of Radiological Sciences
Original Investigation

DOI: 10.1007/s00213-010-1824-9

Cite this article as:
Sekine, M., Arakawa, R., Ito, H. et al. Psychopharmacology (2010) 210: 331. doi:10.1007/s00213-010-1824-9

Abstract

Rationale

Central norepinephrine transporter (NET) is one of the main targets of antidepressants. Although the measurement of NET occupancy has been attempted in humans, the outcomes have been inconclusive.

Objective

In this study, the occupancy of NET by different doses of an antidepressant, nortriptyline, was measured using positron emission tomography (PET) with (S,S)-[18F]FMeNER-D2.

Materials and methods

PET scans using (S,S)-[18F]FMeNER-D2 were performed on six healthy men before and after oral administration of a single oral dose of nortriptyline (10–75 mg). After a bolus i.v. injection of (S,S)-[18F]FMeNER-D2, dynamic scanning was performed for 0–90 min, followed by scanning for 120–180 min. The ratio of the thalamus-to-caudate areas under the curve (120–180 min) minus 1 was used as the binding potential (BPND) for NET. NET occupancy was calculated as the percentage reduction of BPND. Venous blood samples were taken to measure the concentrations of nortriptyline just before injection of the tracer and at 180 min after the injection.

Results

Mean NET occupancies by nortriptyline were 16.4% at 10 mg, 33.2% at 25 mg, and 41.1% at 75 mg. The mean plasma concentration of nortriptyline was less than the lower limit of detection at 10 mg, 23.7 ng/mL at 25 mg, and 50.5 ng/mL at 75 mg. Estimated ED50 was 76.8 mg of administration dose and 59.8 ng/mL of plasma concentration.

Conclusions

NET occupancy by nortriptyline corresponding to the administration dose of 10–75 mg or plasma concentration was observed from 16% to 41%.

Keywords

Norepinephrine transporter (S,S)-[18F]FMeNER-D2 Positron emission tomography Occupancy Nortriptyline

Copyright information

© Springer-Verlag 2010