CAY10397, a selective inhibitor of 15-hydroxy PGDH, significantly suppresses endogenous 11-oxo-ETE production with a corresponding increase in 11(R)-HETE.
20-hydroxy Prostaglandin F2α (20-hydroxy PGF2α) is the ω-oxidation product of PGF2α. Cultured type II alveolar cells from pregnant rabbits metabolize exogenous PGF2α via microsomal cytochrome P450 ω-oxidation, producing 20-hydroxy PGF2α and its 15-hydroxy PGDH metabolites. Cells from male rabbits exhibit only the 15-hydroxy PGDH pathway.
15-keto PGF1α is the initial metabolite of PGF1α via 15-hydroxy PGDH. In mammals, oxidation of C-15 markedly attenuates receptor binding and activity. In fish, the 15-keto compounds serve as post-ovulatory pheromones and are more active than the parent prostaglandins.
Prostaglandin K2 (PGK2), a 9,11-diketone derivative, results from PGE2 or PGD2 oxidation. Its biological presence remains speculative; however, it demonstrates resistance to in vitro metabolism by 15-hydroxy PGDH.
11β-13,14-Dihydro-15-keto PGF2α, a PGD2 metabolite in the 15-hydroxy PGDH pathway, is formed in human males upon infusion or inhalation of tritiated PGD2, with peak plasma levels of both 11β-PGF2α and 11β-13,14-dihydro-15-keto PGF2α observed within 10 minutes. In human lung homogenates, PGD2 is metabolized firstly to 11β-PGF2α and subsequently to 11β-15-keto-PGF2α in the presence of NAD+, but not to 11β-13,14-dihydro-15-keto PGF2α. Conversely, guinea pig liver and kidney homogenates can metabolize PGD2 to 11β-13,14-dihydro-15-keto PGF2α via 11β-PGF2α, with both NAD+ and NADP+ being requisite for this conversion.
15(R)-HETE, a monohydroxy fatty acid, is synthesized from arachidonic acid via aspirin-acetylated COX-2, leading to the formation of specialized pro-resolving mediators 15(R)-lipoxin A4 and B4 through a transcellular mechanism involving 5-lipoxygenase (5-LO). Additionally, this compound is produced by the cytochrome P450 (CYP) isoform CYP2C9 and can be generated from arachidonic acid by COX-1 in human mast cells, where it accumulates due to its resistance to conversion into 15-KETE by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). As an agonist of PPARβ δ, 15(R)-HETE induces the expression of a target gene in NIH3T3 cells, demonstrating its biological significance.
13,14-Dihydro-15-keto prostaglandin D2 (DK-PGD2), a PGD2 metabolite formed by the 15-hydroxyl PGDH pathway, is a selective agonist for the DP2 receptor and can inhibit ion flux in canine colonic mucosa preparation [1].