title: A novel radioligand for imaging the AT1 angiotensin receptor with PET.
abstract: 2-Butyl-5-methoxymethyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-3H-imidazo[4,5-b]pyridine (KR31173) was radiolabeled by coupling a tetrazole-protected hydroxy precursor with [(11)C] methyl iodide and removing the protecting group by acid hydrolysis. In mice, the highest uptake of [(11)C] KR31173 was in the adrenal glands, kidneys, and liver. Tissue to blood ratios were generally greater than 10:1. Uptake of the tracer in the adrenal glands, kidneys, lungs, and heart was blocked with a 1 mg/kg dose of KR31173 or MK-996.
authors.affiliation: Department of Radiology, Room B1151 Nelson Building, Johns Hopkins Medical Institutions, 600 North Wolfe St., Baltimore, MD 21287, USA. bmathews@petscan.nm.jhu.edu
authors.forename: William B
authors.initials: WB
authors.lastname: Mathews
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Yoo
authors.forename: Sung-Hou
authors.initials: SH
authors.lastname: Lee
authors.forename: Ursula
authors.initials: U
authors.lastname: Scheffel
authors.forename: Paige A
authors.initials: PA
authors.lastname: Rauseo
authors.forename: Tamas G
authors.initials: TG
authors.lastname: Zober
authors.forename: Gerard
authors.initials: G
authors.lastname: Gocco
authors.forename: Kathryn
authors.initials: K
authors.lastname: Sandberg
authors.forename: Hayden T
authors.initials: HT
authors.lastname: Ravert
authors.forename: Robert F
authors.initials: RF
authors.lastname: Dannals
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szabo
mesh_terms: D000311:Adrenal Glands / Q000000981:diagnostic imaging* / Q000378:metabolism*; D000818:Animals; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D007093:Imidazoles / Q000493:pharmacokinetics*; D007668:Kidney / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008024:Ligands; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D051379:Mice; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013777:Tetrazoles / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: C493912:2-butyl-5-methoxymethyl-6-(1-oxopyridin-2-yl)-3-((2'-(1H-tetrazol-5-yl)bipohenyl-4-yl)methyl)-3H-imidazo(4,5-b)pyridine; D002250:Carbon Radioisotopes; D007093:Imidazoles; D008024:Ligands; D019275:Radiopharmaceuticals; D044140:Receptor, Angiotensin, Type 1; D013777:Tetrazoles