title: Synthesis and evaluation of 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-[11C]ethyl-1,3-dihydro-2H-benzimidazol-2-one as a brain ORL1 receptor imaging agent for positron emission tomography.
abstract: 1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-[(11)C]ethyl-1,3-dihydro-2H-benzimidazol-2-one ([(11)C]CPEB) was synthesized by [(11)C]N-ethylation and evaluated as a potential brain ORL1 receptor imaging agent by positron emission tomography. The uptake of [(11)C]CPEB in the mouse brain was 1.9% dose/g, 2 min post-injection, and gradually decreased with time. Receptor-specific binding was observed, however, the contribution of other receptors was observed and the non-specific binding of [(11)C]CPEB was too high for imaging receptors in vivo. Therefore, [(11)C]CPEB is not a suitable tracer for in vivo ORL1 receptor imaging.
authors.affiliation: Department of Biofunctional Research, National Institute for Longevity Sciences, Obu 474-8522, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Ogawa
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hatano
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kawasumi
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kawamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ozaki
authors.forename: Kengo
authors.initials: K
authors.lastname: Ito
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D001921:Brain / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism*; D002250:Carbon Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics; D007553:Isotope Labeling / Q000379:methods; D008297:Male; D008657:Metabolic Clearance Rate; D051379:Mice; D008815:Mice, Inbred Strains; D018847:Opioid Peptides / Q000494:pharmacology; D009928:Organ Specificity; D010880:Piperidines / Q000138:chemical synthesis* / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D011957:Receptors, Opioid / Q000378:metabolism*; D012016:Reference Values; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D001562:Benzimidazoles; D002250:Carbon Radioisotopes; D018847:Opioid Peptides; D010880:Piperidines; D019275:Radiopharmaceuticals; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C402921:J 113397; C000722287:Oprl1 protein, mouse