title: Development and validation of a LC/MS/MS method for 6-keto PGF1α, a metabolite of prostacyclin (PGI₂).
abstract: A sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the quantitation of 6-keto PGF(1α) in human urine and plasma. Prostacyclin (PGI(2)) is a locally acting prostanoid, which mediates vasorelaxation and inhibition of platelet aggregation. 6-Keto PGF(1α) is the most-immediate metabolite of PGI(2). Samples were spiked with an internal standard (6-keto PGF(1α)-d(4)), purified by immuno-affinity chromatography and selected reaction monitoring (SRM) was performed. Analytical validation of the 6-keto PGF(1α) assay was performed in urine. This included an assessment of assay precision, recovery, stability, sensitivity and linearity. Urinary 6-keto PGF(1α) concentrations were also correlated to urinary 2,3-dinor-6-keto PGF(1α) (PGIM) concentrations using urine samples collected from 16 healthy volunteers. The mean concentration of 6-keto PGF(1α) in urine (mean ± SD) was 92 ± 51 pg/ml or 168 ± 91 pg/mg creatinine. Overall, there was a statistically significant correlation between urinary 6-keto PGF(1α) and PGIM (r(2)=0.55, p ≤ 0.001; slope=2.7; y-intercept=130). However, PGIM was approximately 3-fold more abundant than 6-keto PGF(1α) in urine. In addition, 6-keto PGF(1α) concentrations were measured in EDTA plasma samples obtained from 7 healthy donors. The mean concentration of 6-keto PGF(1α) in plasma was 1.9 ± 0.8 pg/ml (± SD).
authors.affiliation: Clinical Development Laboratory, Merck Research Laboratories, Rahway, NJ 07065, United States.
authors.forename: Derek L
authors.initials: DL
authors.lastname: Chappell
authors.forename: Xiaoyao
authors.initials: X
authors.lastname: Xiao
authors.forename: Waldemar
authors.initials: W
authors.lastname: Radziszewski
authors.forename: Omar F
authors.initials: OF
authors.lastname: Laterza
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood* / Q000652:urine*; D000293:Adolescent; D000328:Adult; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D003404:Creatinine / Q000652:urine; D011464:Epoprostenol / Q000378:metabolism* / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D059349:Urine Specimen Collection / Q000379:methods; D055815:Young Adult
chemical_list: D015121:6-Ketoprostaglandin F1 alpha; D003404:Creatinine; D011464:Epoprostenol