title: Quantitation and identification of two cholecystokinin peptides, CCK-4 and CCK-8s, in rat brain by HPLC and fast atom bombardment mass spectrometry.
abstract: A sensitive HPLC method has been described for quantitation of two cholecystokinin (CCK) peptides in discrete rat brain regions. Separation and quantitation was performed by the reversed-phase HPLC combined with electrochemical detection. Analytical recoveries of the tetrapeptide (CCK-4) and octapeptide-sulphate (CCK-8s) were 96% and 94%, respectively. The between assay coefficient of variation (CV) was less than 3% for both peptides. The within-assay CV was 4% and 6% for CCK-4 and CCK-8s and the detection limit was 2 and 10 pmol/mL, respectively. For identification of structures, the peptides were fractionated by semi-preparative HPLC using a novel SMART system for micropurification. The fractions were analysed by fast atom bombardment mass spectrometry (FAB MS) which confirmed the presence of both CCK-4 and CCK-8s in the rat brain tissue.
authors.affiliation: Department of Psychiatry, Karolinska Institute, Huddinge, Sweden.
authors.forename: G A
authors.initials: GA
authors.lastname: Qureshi
authors.forename: I
authors.initials: I
authors.lastname: Bednar
authors.forename: Q
authors.initials: Q
authors.lastname: Min
authors.forename: P
authors.initials: P
authors.lastname: Södersten
authors.forename: J
authors.initials: J
authors.lastname: Silberring
authors.forename: F
authors.initials: F
authors.lastname: Nyberg
authors.forename: M
authors.initials: M
authors.lastname: Thörnwall
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000032:analysis*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013758:Tetragastrin / Q000032:analysis*
chemical_list: D013758:Tetragastrin; D012844:Sincalide