RT Journal Article
SR Electronic
T1 Fluorine-18 labeled hydroxy quinoline derivatives as PET tracers for amyloid plaque imaging
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1188
OP 1188
VO 50
IS supplement 2
A1 Padmakar Kulkarni
A1 Neil Vasdev
A1 Veera Arora
A1 Guiyang Hao
A1 Michael Long
A1 Xiankai Sun
A1 Peter Antich
A1 Frederick Bonte
YR 2009
UL http://jnm.snmjournals.org/content/50/supplement_2/1188.abstract
AB 1188 Objectives To develop [18F] labeled hydroxy quinoline derivatives for PET imaging of amyloid plaques expressing elevated levels of metal ions. Methods 8-Benzyloxy-2-chloroquinoline was reacted with [K222][18F] in DMSO at 135 oC, followed by catalytic hydrogenation. The product was purified by HPLC and formulated in 70 min. Male Swiss Webster mice (~25 g) were used. Aβ (1-42) peptide aggregates (10 μg in 25 μl PBS) were injected into hippocampus of experimental animals (expt) (n=4). Control animals received saline. After 6 weeks, they were imaged in a Siemens Inveon PET-CT scanner. Data acquisition was up to 30 min starting immediately after i.v. injection of the tracer (50-60 μC). Expt mice brain sections showed positive Congo red stain. Results [18F]-8-hydroxy-2-fluoroquinoline was prepared in 30±4% (n=5) RCY (uncorrected), with >99% RCP. Specific activity was 1248 mCi/μmol and Log P (pH 7.4) was 2.07±0.03. PET images showed fast uptake and rapid washout of the tracer from the control mouse brain. Brain time-activity curves were generated, taking the value at 0.5 min as 100%. For control animals, brain activity at 6.5 min was 13±4% and reached a plateau. Expt animals had much slower washout (24±5% at 6.5 min) and reached a plateau (21±5%) at 10 min. Expt animal brain activity was 180% of the control animals at 6.5 min and remained at 140%. Further analysis of PET data is continuing. Conclusions We have prepared a new [18F] labeled radiotracer based on a hydroxy quinoline derivative for imaging amyloid plaques. These studies warrant further evaluation of this class of molecules as amyloid imaging agents.