UNLABELLED Brain kappa-opioid receptors (ORs) may be involved in several pathologic conditions, such as addiction, psychosis, and seizures. (+/-)-4-Methoxycarbonyl-2-[(1-pyrrolidinylmethyl]-1-[(3,4-dichlorophenyl)acetyl]-piperidine (GR89696) is a potent and selective kappa-OR agonist. The (-)-isomer, GR103545, is the active enantiomer of GR89696. The aim of this study was to characterize the po...

The standard method of [11C]raclopride synthesis requires a large amount of its desmethyl precursor. We prepared [11C]raclopride by methylation of a small amount of desmethyl derivative (0.3-0.5 mg) with [11C]methyl iodide in a DMF solution containing NaH, with a decay-corrected radiochemical yield of 11-14% based on [11C]methyl iodide and with a specific activity of 48 TBq/mmol for 25 min from...

During cholestasis, accumulation of conjugated bile acids may occur in the liver and lead to hepatocellular damage. Inspired by our recent development of N-11C-methyl-glycocholic acid—that is, 11C-cholylsarcosine—a tracer for PET of the endogenous glycine conjugate of cholic acid, we report here a radiosynthesis of N-11C-methyltaurine–conjugated bile acids and biodistribution studies in pigs by...

OBJECTIVES Both reconstruction algorithms, filtered backprojection (FBP) and ordered subsets expectation maximization (OSEM), are widely used in clinical positron emission tomography (PET) studies. Image reconstruction for most neurotransmission PET scan data is performed by FBP, while image reconstruction for whole-body [18F]FDG scan data is usually performed by OSEM. Although several investig...

BACKGROUND Androgen deprivation (AD) is generally used as a first-line palliative treatment in prostate cancer (PCa) patients with rising prostate-specific antigen (PSA) after primary therapy. To acquire an accurate detection of tumour viability following AD with positron emission tomography (PET), an androgen-independent uptake of tracers would be advantageous. Several metabolic PET tracers ar...

Tumor uptake of L-[methyl-11C]methionine ([11C]Met) was assessed in six patients with brain tumors and three patients with lung cancer using positron emission tomography (PET). In arterial plasma samples taken at 5, 15, 30, and 60 min after injection, a fraction of [11C]Met was measured using high performance liquid chromatography in individual patients. Employing curve fitting, a history of [1...

Octanoate is taken up into the brain and is converted in astrocytes to glutamine through the TCA cycle after beta-oxidation. We speculate that [1-11C]octanoate may be used as a tracer for astroglial functions and/or fatty acid metabolism in the brain and may be useful for studying cerebral ischemia. In the present study we investigated brain distribution of [1-11C]octanoate and compared it with...

The aim of the present study was to determine the effect of "binge" pattern cocaine administration on dopamine D1 and D2 receptors in the rat brain. Male Sprague Dawley rats were injected three times at 1 hr intervals with saline or cocaine (15 mg/kg) each day for 2, 7, or 14 d. The in vivo binding of [11C]SCH23390 (dopamine D1 receptor antagonist) and [11C]N-methylspiperone (NMSP; dopamine D2 ...

UNLABELLED The development of the radioligands for PET imaging of the cerebral cannabinoid receptor (CB1) is of great importance for studying its role in neuropsychiatric disorders, obesity, and drug dependence. None of the currently available radioligands for CB1 are suitable for quantitative PET, primarily because of their insufficient binding potential (BP) in brain or low penetration throug...

Objective: To study 5-HT transport and 5-HT1A receptors in temporal lobe epilepsy (TLE) and depression. Methods: Thirteen patients had PET with [11C]DASB for 5-HTT and [18F]FCWAY for 5-HT1A receptor binding, MRI, and psychiatric assessment. Sixteen healthy volunteers had [11C]DASB, 19 had [18F] FCWAY, and 6 had both PET studies. We used a reference tissue model to estimate [11C]DASB binding. [1...