Quantitative analysis of 5-oxo-6,8,11,14-eicosatetraenoic acid by electrospray mass spectrometry using a deuterium-labeled internal standard.
5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), a metabolite of arachidonic acid formed by the 5-lipoxygenase pathway, is a potent eosinophil chemoattractant that may be an important mediator in asthma. To further investigate the physiological and pathological roles of 5-oxo-ETE we have developed a mass spectrometric assay employing a tetradeuterated analog (5-oxo-[11,12,14,15-(2)H]ETE) as an internal standard. Collision-induced dissociation of the quasimolecular anion of 5-oxo-[11,12,14,15-(2)H]ETE (m/z 321) resulted in the formation of a major ion at m/z 207 that retained all four deuterium atoms. Measurement of the ratio of ions at m/z 203 (endogenous 5-oxo-ETE) and m/z 207 permitted quantitation of this compound by liquid chromatography-mass spectrometry-mass spectrometry using multiple reaction monitoring. The resulting assay was highly sensitive (< or =20 pg/sample) and selective, enabling detection of the amount of 5-oxo-ETE produced by as few as 10,000 neutrophils. This assay should permit measurement of 5-oxo-ETE in biological fluids, enabling evaluation of its role in asthma and other inflammatory diseases.
Powell
W S
WS
Meakins-Christie Laboratories, Department of Medicine, McGill University, 3626 St. Urbain Street, Montreal, Quebec, Canada H2X 2P2.
Boismenu
D
D
Khanapure
S P
SP
Rokach
J
J
D001095:Arachidonic Acids / Q000032:analysis* / Q000592:standards; D001826:Body Fluids / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D003903:Deuterium; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D012015:Reference Standards
D001095:Arachidonic Acids; C080828:5-oxo-6,8,11,14-eicosatetraenoic acid; D003903:Deuterium