PET studies of 18F-memantine in healthy volunteers.
Previous studies in mice and PET investigations in a Rhesus monkey showed that the regional uptake of 18F-memantine could be blocked by pharmacological doses of memantine and (+)-MK-801. In the present study, the binding characteristics of 18F-memantine was examined in five healthy volunteers. In humans, 18F-memantine was homogeneously distributed in gray matter i.e. cortex and basal ganglia regions, as well as the cerebellum. No radioactive metabolites were detected in plasma during the time-frame of the PET studies. The uptake of 18F-memantine in receptor-rich regions such as striatum and frontal cortex could be well described by a 1-tissue compartment model. The DV" values of all gray matter regions were similar and ranged from 15 to 20 ml/ml. The white matter showed lower DV" values of 15 +/- 1.4 ml/ml. These results suggest that 18F-memantine distribution in human brain does not reflect the regional NMDA receptor concentration, and therefore, this radioligand is not suitable for the PET imaging of the NMDA receptors.
Ametamey
S M
SM
Center for Radiopharmaceutical Science of ETH, PSI and USZ, CH-5232 -PSI, Villigen, Switzerland. simon-mensah.ametamey@psi.ch
Bruehlmeier
M
M
Kneifel
S
S
Kokic
M
M
Honer
M
M
Arigoni
M
M
Buck
A
A
Burger
C
C
Samnick
S
S
Quack
G
G
Schubiger
P A
PA
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D008297:Male; D008559:Memantine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D011869:Radioligand Assay; D019275:Radiopharmaceuticals / Q000097:blood / Q000493:pharmacokinetics*; D016194:Receptors, N-Methyl-D-Aspartate / Q000032:analysis / Q000378:metabolism*; D012016:Reference Values; D014055:Tomography, Emission-Computed
C114150:1-amino-3-fluoromethyl-5-methyladamantane; D019275:Radiopharmaceuticals; D016194:Receptors, N-Methyl-D-Aspartate; D008559:Memantine