Development and validation of a LC/MS/MS method for 6-keto PGF1α, a metabolite of prostacyclin (PGI2)

Analytical validation of the 6-keto PGF1α assay was performed in urine. This included an assessment of assay precision, recovery, stability, sensitivity and linearity. Urinary 6-keto PGF1α concentrations were also correlated to urinary 2,3-dinor-6-keto PGF1α (PGIM) concentrations using urine samples collected from 16 healthy volunteers. The mean concentration of 6-keto PGF1α 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 PGF1α and PGIM (r2 = 0.55, p ≤ 0.001; slope = 2.7; y-intercept = 130). However, PGIM was approximately 3-fold more abundant than 6-keto PGF1α in urine. In addition, 6-keto PGF1α concentrations were measured in EDTA plasma samples obtained from 7 healthy donors. The mean concentration of 6-keto PGF1α in plasma was 1.9 ± 0.8 pg/ml (±SD).