title: Determination of an unstable pentapeptide, monocyte locomotion inhibitory factor, in dog blood by LC-MS/MS: application to a pharmacokinetic study.
abstract: A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and established for the quantitative determination of monocyte locomotion inhibitory factor, a pentapeptide (Met-Gln-Cys-Asn-Ser) produced by Entamoeba histolytica in axenic culture, in dog blood. The main challenge was the chemical and enzymatic instability of the peptide which was successfully overcome. After a simple protein precipitation, MLIF was separated from AS-5 (Met-Gln-Gly-Asn-Ser), acted as an internal standard, on a Gemini C18 column (5 μm, 50 mm × 4.6 mm i.d.) using a gradient elution of acetonitrile (0.2% formic acid) and water (0.2% formic acid) and detected by electrospray ionization tandem mass spectrometry. Excellent linearity was achieved (r>0.9943) over the linear range 5-1000 ng/ml using 0.2 ml blood sample. The validation results demonstrated that this method was specific, accurate and precise. It was successfully applied in measuring MLIF following intravenous infusion its administration at 0.2, 0.4, and 0.8 mg/kg in beagle dogs to support the pre-clinical pharmacokinetic study.
authors.affiliation: School of Pharmacy, Second Military Medical University, No. 325 Guohe Road, Shanghai 200433, PR China.
authors.forename: Huafang
authors.initials: H
authors.lastname: Jiang
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Zhao
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.forename: You
authors.initials: Y
authors.lastname: Li
authors.forename: Fanlu
authors.initials: F
authors.lastname: Sun
authors.forename: Xun
authors.initials: X
authors.lastname: Hu
authors.forename: Jinghua
authors.initials: J
authors.lastname: Huang
authors.forename: Yaocheng
authors.initials: Y
authors.lastname: Rui
authors.forename: Guorong
authors.initials: G
authors.lastname: Fan
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D004285:Dogs; D009842:Oligopeptides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D009842:Oligopeptides; C430647:monocyte locomotion inhibitory factor