title: LC-MS/MS-analysis of sphingosine-1-phosphate and related compounds in plasma samples.
abstract: Sphingosine-1-phosphate (S1P) and related compounds are important signaling molecules and are normal constituents of human plasma. So far, only a few methods exist for their determination specifically in plasma demanding radioactive agents, more or less time consuming extraction or derivatization procedures. Here, we describe a very simple, reliable, sensitive standard-addition method for the simultaneous determination of S1P, sphingosine (SPH), sphinganine (SAPH) and sphinganine-1-phosphate (SA1P) in human and rat plasma samples. After methanol precipitation of plasma samples the supernatants were directly assessed by liquid chromatography-electrospray ionisation-tandem mass spectrometry (LC-ESI-MS/MS). HPLC analysis was done under gradient conditions using a C18 reversed phase column. The lower limit of quantification (LLOQ) was <10.2, <4.6, <1.9 and 0.57ng/ml for S1P, SPH, SAPH and SA1P, respectively. Variations in accuracy and intraday and interday precision were <15% over the range of calibration. All analytes were normal constituents both in human and rat plasma although the SA1P concentrations in a few rat plasma samples were below the lower limit of quantification. This validated method is suitable to generate new pharmacological findings by monitoring plasma concentrations of S1P and related compounds especially when low amounts of plasma samples are present (e.g. plasma samples from rodents).
authors.affiliation: Pharmazentrum Frankfurt/ZAFES, Institut für Klinische Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany. Helmut.Schmidt@em.uni-frankfurt.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Schmidt
authors.forename: Ronald
authors.initials: R
authors.lastname: Schmidt
authors.forename: Gerd
authors.initials: G
authors.lastname: Geisslinger
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D008246:Lysophospholipids / Q000097:blood*; D000432:Methanol / Q000737:chemistry; D051381:Rats; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000097:blood*; D013997:Time Factors
chemical_list: D008246:Lysophospholipids; C060504:dihydrosphingosine 1-phosphate; C060506:sphingosine 1-phosphate; D013110:Sphingosine; C005682:safingol; D000432:Methanol