1. Radiosynthesis and Evaluation of [11C-Carbonyl]-Labeled Carbamates as Fatty Acid Amide Hydrolase Radiotracers for Positron Emission Tomography
- Author
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Christopher J. Fowler, Justin W. Hicks, Jun Parkes, Oleg Sadovski, Neil Vasdev, Junchao Tong, Alan A. Wilson, and Sylvain Houle
- Subjects
Stereochemistry ,01 natural sciences ,Article ,Amidohydrolases ,Structure-Activity Relationship ,03 medical and health sciences ,0302 clinical medicine ,Fatty acid amide hydrolase ,In vivo ,Drug Discovery ,medicine ,Animals ,Humans ,Structure–activity relationship ,Tissue Distribution ,Carbon Radioisotopes ,medicine.diagnostic_test ,010405 organic chemistry ,Chemistry ,Radiosynthesis ,Brain ,Endocannabinoid system ,Rats ,3. Good health ,0104 chemical sciences ,nervous system ,Biochemistry ,Positron emission tomography ,Isotope Labeling ,Positron-Emission Tomography ,Molecular Medicine ,lipids (amino acids, peptides, and proteins) ,Carbamates ,psychological phenomena and processes ,030217 neurology & neurosurgery ,Preclinical imaging ,Ex vivo ,Protein Binding - Abstract
Fatty acid amide hydrolase (FAAH) plays a key role in regulating the tone of the endocannabinoid system. Radiotracers are required to image and quantify FAAH activity in vivo. We have synthesized a series of potent FAAH inhibitors encompassing two classes of N-alkyl-O-arylcarbamates and radiolabeled eight of them with carbon-11. The [¹¹C-carbonyl]-radiotracers were evaluated in vitro and ex vivo in rats as potential FAAH imaging agents for positron emission tomography (PET). Both sets of [¹¹C]O-arylcarbamates showed good to excellent brain penetration and an appropriate regional distribution. Pretreatments with a FAAH inhibitor demonstrated that 80-95% of brain uptake of radioactivity constituted binding of the radiotracers to FAAH. Brain extraction measurements showed that binding to FAAH was irreversible and kinetically different for the two classes of carbamates. These promising results are discussed in terms of the requirements of a suitable radiotracer for the in vivo imaging of FAAH using PET. more...
- Published
- 2012
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