13,14-dihydro-15-keto Prostaglandin E2-d9 (13,14-dihydro-15-keto PGE2-d9) is intended for use as an internal standard for the quantification of 13,14-dihydro-15-keto PGE2 by GC- or LC-MS. 13,14-dihydro-15-keto PGE2 is the primary metabolite of PGE2 in plasma.1 Endogenous or infused PGE2 is rapidly metabolized by the enzymes 15-hydroxy PGDH and 15-oxo-PG δ13-reductase to form 13,14-dihydro-15-keto PGE2. 13,14-dihydro-15-keto PGE2 accumulates to detectable levels; plasma levels in humans are between 10-100 pg/ml.2,3 It undergoes further metabolism and chemical decomposition, giving it a relatively short half-life. In dogs, the plasma half-life of 13,14-dihydro-15-keto PGE2 is about 9 minutes.3 In humans the metabolite has a similar short half-life, making it a poor choice of analytes for assays designed to measure total PGE2 biosynthesis.4,5
1.Hamberg, M., and Samuelsson, B.On the metabolism of prostaglandins E1 and E2 in manJ. Biol. Chem.246(22)6713-6721(1971) 2.Fitzpatrick, F.A., Aguirre, R., Pike, J.E., et al.The stability of 13,14-dihydro-15 keto-PGE2Prostaglandins19(6)917-931(1980) 3.Bothwell, W., Verburg, M., Wynalda, M., et al.A radioimmunoassay for the unstable pulmonary metabolites of prostaglandin E1 and E2: An indirect index of their in vivo disposition and pharmacokineticsJ. Pharmacol. Exp. Ther.220(2)229-235(1982) 4.Leonhardt, A., Krauss, M., Gieler, U., et al.In vivo formation of prostaglandin E1 and prostaglandin E2 in atopic dermatitisBr. J. Dermatol.136(3)337-340(1997) 5.GranstrÖm, E., Hamberg, M., Hansson, G., et al.Chemical instability of 15-keto-13,14-dihydro-PGE2: The reason for low assay reliabilityProstaglandins19(6)933-945(1980)