Imaging the norepinephrine transporter with positron emission tomography: initial human studies with (S,S)-[18F]FMeNER-D2.
BACKGROUND
(S,S)-[(18)F]FMeNER-D(2) is a recently developed positron emission tomography (PET) ligand for in vivo quantification of norepinephrine transporter. A monkey occupancy study with the radioligand indicated that (S,S)-[(18)F]FMeNER-D(2) can be useful for quantitative PET analysis. In this preliminary study, regional distributions in the living human brain were evaluated.


METHODS
Brain PET measurements were performed for a total of 255 min after the injection of 188.3 +/- 5.7 MBq of (S,S)-[(18)F]FMeNER-D(2) in four healthy male subjects. Regions of interests were drawn on the thalamus and the caudate in the coregistered MRI/PET images.


RESULTS
(S,S)-[(18)F]FMeNER-D(2) displayed good brain penetration and selective retention in regions rich in norepinephrine reuptake sites. The transient peak equilibrium was reached during the PET measurements. The ratios of radioactivity uptake in the thalamus to that in the caudate were 1.50 +/- 0.06 for the time period of 90-255 min.


CONCLUSIONS
The present preliminary investigation indicates that (S,S)-[(18)F]FMeNER-D(2) has suitable characteristics for probing the norepinephrine reuptake system with PET in the human brain.
Takano
Akihiro
A
Psychiatry Section, Department of Clinical Neuroscience, Karolinska Institutet, 171 76, Stockholm, Sweden. Christer.Halldin@ki.se
Gulyás
Balázs
B
Varrone
Andrea
A
Karlsson
Per
P
Schou
Magnus
M
Airaksinen
Anu J
AJ
Vandenhende
Francois
F
Tauscher
Johannes
J
Halldin
Christer
C
D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008297:Male; D009025:Morpholines / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D050484:Norepinephrine Plasma Membrane Transport Proteins / Q000032:analysis* / Q000378:metabolism; D049268:Positron-Emission Tomography; D013237:Stereoisomerism; D014018:Tissue Distribution; D055815:Young Adult
C506462:2-(alpha-(2-fluoromethoxyphenoxy)benzyl)morpholine; D009025:Morpholines; D050484:Norepinephrine Plasma Membrane Transport Proteins