RT Journal Article
SR Electronic
T1 Synthesis of 5-Oxo-6,8,11,14-eicosatetraenoic Acid and Identification of Novel ω-Oxidized Metabolites in the Mouse Macrophage
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 293
OP 305
VO 296
IS 2
A1 John M. Hevko
A1 Rebecca C. Bowers
A1 Robert C. Murphy
YR 2001
UL http://jpet.aspetjournals.org/content/296/2/293.abstract
AB The metabolism of arachidonic acid by the 5-lipoxygenase pathway not only leads to the formation of leukotrienes but also to the biologically active eicosanoid 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE). The synthesis of 5-oxo-ETE was investigated in the elicited peritoneal macrophage and the formation of 5-hydroxyeicosatetraenoic acid (5-HETE) as well as 5-oxo-ETE was quantitated using stable isotope dilution tandem mass spectrometry. The metabolism of 5-oxo-ETE in these same cells led to the formation of a series of novel less lipophilic metabolites oxidized near the methyl terminus that were structurally characterized using electrospray LC/MS and LC/MS/MS. Five novel metabolites of 5-oxo-ETE were identified including 5,18-diHETE, 5,19-diHETE, 5-oxo-19-HETrE, 5-oxo-18-HETrE, and 5,19-diHETrE. These metabolites corresponded to ω-1 and ω-2 oxidation of 5-oxo-ETE presumably formed by a specific cytochrome P450. There was no evidence for the formation of ω-oxidation (20-hydroxy metabolites), which are known products of metabolism of 5-oxo-ETE in other cell types. None of the metabolites were found to elevate intracellular calcium release, suggesting that this metabolic pathway may result in inactivation of 5-oxo-ETE. This is the first report of the biosynthesis of 5-oxo-ETE by tissue resident cell outside of the blood and the formation of novel ω-1 and ω-2 oxidation of this eicosanoid.