Tandem mass spectrometric quantification of 8-iso-prostaglandin F2alpha and its metabolite 2,3-dinor-5,6-dihydro-8-iso-prostaglandin F2alpha in human urine.
Whole body synthesis of F2-isoprostanes, a family of cyclooxygenase-independent eicosanoids formed by free-radical catalysed peroxidation, should be best assessed by quantifying their urinary metabolites. Two methods for the quantitative determination of F2-isoprostane metabolites in human urine performing either thin-layer chromatography (TLC) (method A) or high-performance liquid chromatography (HPLC) (method B) prior to GC-tandem MS are described. Method A allows for simultaneous quantification of 8-iso-PGF2alpha, one prominent member of the F2-isoprostane family, and its major urinary metabolite, 2,3-dinor-5,6-dihydro-8-iso-PGF2alpha. Mean excretion was found to be 223 and 506 pg/mg creatinine of 8-iso-PGF2alpha and 2,3-dinor-5,6-dihydro-8-iso-PGF2alpha, respectively (n=14). A tight correlation existed between the urinary excretion of these two isoprostanes (r=0.86). Method B enables quantification of dinor-dihydro metabolites of various F2-isoprostanes including 8-iso-PGF2alpha. 2,3-Dinor-5,6-dihydro-8-iso-PGF2alpha was found to be an abundant dinor-dihydro F2-isoprostane metabolite. Validity of method A was proven by a combination of HPLC with TLC prior to GC-tandem MS analysis. A correlation was observed between the urinary concentrations of 2,3-dinor-5,6-dihydro-8-iso-PGF2alpha measured by GC-MS and GC-tandem MS (r=0.84).
Schwedhelm
E
E
Institute of Clinical Pharmacology, Hannover Medical School, Germany.
Tsikas
D
D
Durand
T
T
Gutzki
F M
FM
Guy
A
A
Rossi
J C
JC
Frölich
J C
JC
D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine*; D028441:F2-Isoprostanes; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008297:Male; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results
C411579:2,3-dinor-5,6-dihydro-8-iso-prostaglandin F2(alpha); D028441:F2-Isoprostanes; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost