Synthesis of 11C-labeled capsaicin ([11C]-2) was accomplished by O-[11C]methylation with [11C]methyl iodide to a corresponding catechol precursor (1). In vivo whole-body distribution of [11C]-2 in rats was investigated by positron emission tomography after intravenous injection. The results showed that [11C]-2 accumulated in the brain and body surface, which was closely associated with the expr...

Objective(s): This study aimed to compare the diagnostic values of 11C-choline and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with cholangiocarcinoma (CCA). Methods: This prospective study was conducted on 10 patients (6 males and 4 females), aged 42-69 years, suspected of having CCA based on CT or magnetic resonance imaging (MRI) resu...

The localization of quaternized muscarinic receptor (mAChR) antagonists, [11C]methyl tropanyl benzilate ([11C]MTRB) and [11C]methyl quinuclidinyl benzilate ([11C]MQNB), in rat pituitary was compared to that of [11C]tropanyl benzilate ([11C]TRB), a neutral antagonist. The quaternized ligands localize via a mAChR-mediated mechanism as shown by 60% reduction in radioactivity concentrations in the ...

[11C]-(+)-PHNO (4-propyl-9-hydroxynaphthoxazine) is a new agonist radioligand that provides a unique opportunity to measure the high-affinity states of the D2 receptors (D2-high) using positron emission tomography (PET). Here we report on the distribution, displaceablity, specificity and modeling of [11C]-(+)-PHNO and compare it with the well characterized antagonist D2 radioligand, [11C]raclop...

4-Acetoxy derivative (1) of L-703,717, a high-affinity (IC50=4.5 nM) antagonist for the glycine site of NMDA receptors, was synthesized and its brain uptake was examined using a carbon-11 labeled analog ([11C]1). Initial radioactivity in the brain after intravenous injection of [11C]1 was a 2-fold that of [11C]L-703,717 in mice. Rapid bioconversion of [11C]1 into [11C]L-703,717 was demonstrated...

In previous in vivo studies with mice, rats, cats and monkeys, we have demonstrated that [7-methyl-11C]-(E)-8-(3,4,5-trimethoxystyryl)- 1,3,7-trimethylxanthine ([11C]TMSX) is a potential radioligand for mapping adenosine A2A receptors of the brain by positron emission tomography (PET). In the present study, we studied the potential of [11C]TMSX for myocardial imaging. Uptake of radioactivity by...

Carbon-11-labeled SarCNU [N-(2-chloroethyl)-N-nitroso-N'-(carboxamidomethylene)-N'-(methyl) - [11C]-urea], a potential chemotherapeutic agent, has been prepared by the nitrosation of the corresponding urea, N-(2-chloroethyl)-N'-(carboxamidomethylene)-N'-(methyl) [11C]urea (SarCU). SarCU was prepared by reacting sarcosinamide with [11C]-2-chloroethylisocyanate, which was itself prepared by react...

I investigated the differences in brain pharmacokinetics of [11C]methamphetamine ([11C]MAP) in normal and MAP sensitized animals using positron emission tomography (PET). [11C]MAP was synthesized by an automated on-line [11C]methylation system. I newly produced MAP sensitized dog and monkey by repeated MAP treatment. The maximal level of accumulation of [11C]MAP in the sensitized dog brain was ...

BACKGROUND Therapeutic drug monitoring of phenytoin by measurement of plasma concentrations is often employed to optimize clinical efficacy while avoiding adverse effects. This is most commonly accomplished by measurement of total phenytoin plasma concentrations. However, total phenytoin levels can be misleading in patients with factors such as low plasma albumin that alter the free (unbound) c...

The present study evaluated short- and long-term effects of MDMA (3,4-methylenedioxymethamphetamine) in the baboon brain using PET and [11C](+)McN 5652, a potent 5-HT transporter ligand, as well as [11C]RTI-55, a cocaine derivative which labels both 5-HT and dopamine transporters. Following baseline PET scans with [11C](+)McN5652, [11C](-)McN5652 (the inactive enantiomer of the active enantiome...