title: Quantification of ghrelin and des-acyl ghrelin in human plasma by using cubic-selected reaction-monitoring LCMS.
abstract: BACKGROUND
  Ghrelin is a peptide hormone generally measured in plasma by immunoassays. LCMS/MS was investigated as an alternative method in particular for the quantification of the two forms of the peptide with improved selectivity.
  
  
  METHODS
  A LCMS assay using a cubic-selected reaction-monitoring (LCSRM(3)/MS) mode was developed for the quantification of ghrelin and des-acyl ghrelin in human plasma.
  
  
  RESULTS
  The LCSRM(3)/MS method was found to be linear from 50-75 to 2500 pg/ml for the ghrelins using a 0.5-ml plasma sample. The accuracies and precisions at LOQ for des-acyl ghrelin (50 pg/ml) and ghrelin (75 pg/ml) were found to be better than 91 and 2%, respectively. Blood and plasma stabilization was found to be essential for good assay performance.
  
  
  CONCLUSIONS
  Compared to the LCSRM/MS method the addition of an additional MS step did significantly improve the selectivity and therefore the sensitivity. The LCSRM(3)/MS method could be successfully applied for the quantification of ghrelin and des-acyl ghrelin in human plasma samples.
authors: School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Life Sciences Mass Spectrometry, Quai Ernest-Ansermet 30, 1211 Geneva, Switzerland.
authors: Jonathan
authors: J
authors: Sidibé
authors: Emmanuel
authors: E
authors: Varesio
authors: Gérard
authors: G
authors: Hopfgartner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D054439:Ghrelin / Q000097:blood* / Q000737:chemistry / Q000592:standards; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D011786:Quality Control; D051381:Rats; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D054439:Ghrelin; C422650:ghrelin, des-n-octanoyl