Article Figures & Data
Figures
- FIGURE 1.
(A) Schema for synthesis of precursors 4NP3, 2NP3, 4NPMP, and 2NPMP, and radiosynthesis of 18F-4FP3, 18F-2FP3, 18F-4FPMP, and 18F-2FPMP. (B) Chromatogram of HPLC purification of 18F-2FP3 (ultraviolet absorbance at 254 nm and radioactivity). (C) Quality control chromatogram of final 18F-2FP3 (ultraviolet absorbance at 254 nm and radioactivity) shows radiochemical purity greater than 99%. DMSO = dimethyl sulfoxide; EOB = end of bombardment; radio = radioactivity detection; UV = ultraviolet detection.
- FIGURE 2.
(A) In vitro autoradiograms of rat brain sections incubated with 18F-4FP3, 18F-2FP3, 18F-4FPMP, or 18F-2FPMP show locations and density of 5-HT7 receptors (proportional to gray level) in hippocampus (Hip), cortex (Cx), and thalamus (Thal). (B) Histograms obtained by in vitro autoradiography in rats and competition between 18F-4FP3, 18F-2FP3, 18F-4FPMP, 18F-2FPMP, and SB269970, a 5-HT7 receptor antagonist. Radioactivity in cortex is represented at different concentrations and expressed as percentage of control. Mean values (±SEM) for each group are significantly different (*P < 0.05) from controls on unpaired Student t test. DMSO = dimethyl sulfoxide; EOB = end of bombardment; radio = radioactivity detection; UV = ultraviolet detection.
- FIGURE 3.
Ex vivo coronal small-animal PET images of 18F-4FP3 or 18F-2FP3 binding in isolated rat brain (45-min acquisition), 20 min after radioligand injection.
- FIGURE 4.
(A) Representative sagittal PET images summed for 0–90 scans, showing 18F-4FP3 and 18F-2FP3 distribution in cat brain. (B) Time–activity curves of 18F-4FP3 and 18F-2FP3 PET tracers at baseline (closed symbols) and after blockade with intravenous SB269970 (open symbols), a 5-HT7 antagonist (5 mg/kg, 30 min before radiotracer injection) (duplicated experiments).
