Neurokinin-3 Receptor Binding in Guinea Pig, Monkey, and Human Brain: In Vitro and in Vivo Imaging Using the Novel Radioligand, [18F]Lu AF10628.

Background: Previous autoradiography studies have suggested a marked interspecies variation in the neuroanatomical localization and expression levels of the neurokinin 3 receptor, with high density in the brain of rat, gerbil, and guinea pig, but at the time offered no conclusive evidence for its presence in the human brain. Hitherto available radioligands have displayed low affinity for the human neurokinin 3 receptor relative to the rodent homologue and may thus not be optimal for cross-species analyses of the expression of this protein.

Methods: A novel neurokinin 3 receptor radioligand, [(18)F]Lu AF10628 ((S)-N-(cyclobutyl(3-fluorophenyl)methyl)-8-fluoro-2-((3-[(18)F]-fluoropropyl)amino)-3-methyl-1-oxo-1,2-dihydroisoquinoline-4-carboxamide), was synthesized and used for autoradiography studies in cryosections from guinea pig, monkey, and human brain as well as for positron emission tomography studies in guinea pig and monkey.

Expression, purification, and characterization of a soluble form of the first extracellular domain of the human type 1 corticotropin releasing factor receptor.

The first extracellular domain (ECD-1) of the corticotropin releasing factor (CRF) type 1 receptor, (CRFR1), is important for binding of CRF ligands. A soluble protein, mNT-CRFR1, produced by COS M6 cells transfected with a cDNA encoding amino acids 1--119 of human CRFR1 and modified to include epitope tags, binds a CRF antagonist, astressin, in a radioreceptor assay using [(125)I-d-Tyr(0)]astressin. N-terminal sequencing of mNT-CRFR1 showed the absence of the first 23 amino acids of human CRFR1.

A comparison of a non-ionic dimer, iodixanol with a non-ionic monomer, iohexol in low dose intravenous urography.

A prospective, double-blind study of 392 patients randomized into four groups was performed to establish whether diagnostic intravenous urograms could be obtained with a lower dose of iodine when using the dimeric, non-ionic contrast medium iodixanol compared with the monomeric, non-ionic iohexol. Patients received iodixanol or iohexol containing either 9 or 12 g of iodine (gI). The primary parameter was the diagnostic quality of the 6 min film, assessed in a blinded fashion, by consensus, by four radiologists.