2750534-81-5

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 a metabolite of PGE₂ and the primary PGE₂ metabolite in plasma.^1,2 It is formed from PGE₂ via a 15-keto PGE₂ intermediate by 15-oxo-PG Δ¹³ reductase.² Unlike PGE₂, 13,14-dihydro-15-keto PGE₂ does not bind effectively to the PGE₂ receptors EP₂ and EP₄ expressed in CHO cells (K_is = 12 and 57 μM, respectively) or induce adenylate cyclase activity in the same cells (EC₅₀s = >18 and >38 μM, respectively). Levels of 13,14-dihydro-15-keto PGE₂ are increased in the plasma of women in the third trimester of pregnancy and in women during and immediately after labor and delivery.³ Levels of 13,14-dihydro-15-keto PGE₂ levels are decreased in tumor tissue compared to adjacent non-cancerous tissue isolated from patients with non-small cell lung cancer (NSCLC).⁴

1. Hamberg, M., and Samuelsson, B. On the metabolism of prostaglandins E₁ and E₂ in man J. Biol. Chem. 246(22),6713-6721(1971).
2. Nishigaki, N., Negishi, M., and Ichikawa, A. Two Gs-coupled prostaglandin E receptor subtypes, EP₂ and EP₄, differ in desensitization and sensitivity to the metabolic inactivation of the agonist Mol. Pharmacol. 50(4),1031-1037(1996).
3. Husslein, P., and Sinzinger, H. Concentration of 13,14-dihydro-15-keto-prostaglandin E₂ in the maternal peripheral plasma during labour of spontaneous onset Br. J. Obstet. Gynaecol. 91(3),228-231(1984).
4. Hughes, D., Otani, T., Yang, P., et al. NAD⁺-dependent 15-hydroxyprostaglandin dehydrogenase regulates levels of bioactive lipids in non-small cell lung cancer Cancer Prev. Res. (Phila.) 1(4),241-249(2008).