title: Improved method for the determination of cyclic guanosine monophosphate (cGMP) in human plasma by LC-MS/MS.
abstract: Cyclic guanosine monophosphate (cGMP) is an important second messenger molecule involved in gating ion channels and activating protein kinases. Here, we describe a validated LC-MS/MS method for the quantification of cGMP in human plasma, utilizing a stable isotope labeled analogue of cGMP as I.S. Plasma samples were extracted and concentrated by weak anion exchange solid phase extraction and the extracts were chromatographically separated on a porous graphitic carbon column. The analytes were detected by positive electrospray ionization and tandem mass spectrometry. The calibration function was linear in the range 1-20 nM and the intra- and inter-day precision showed relative standard deviations of better than 2 and 6%, respectively. The accuracy was always better than 4%. Plasma concentrations in healthy human subjects determined with this method were 3.92+/-1.17 nM (n=20). The method was, due to its isotope labeled I.S., matrix independent.
authors.affiliation: Institute of Clinical Pharmacology, Otto-von-Guericke University, Magdeburg 39120, Germany. jens.martens-lobenhoffer@med.ovgu.de
authors.forename: Jens
authors.initials: J
authors.lastname: Martens-Lobenhoffer
authors.forename: Christin
authors.initials: C
authors.lastname: Dautz
authors.forename: Stefanie M
authors.initials: SM
authors.lastname: Bode-Böger
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D006152:Cyclic GMP / Q000097:blood*; D006801:Humans; D007553:Isotope Labeling; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D006152:Cyclic GMP