Ultra-Performance Liquid Chromatography-Mass Spectrometry Analysis of Free and Esterified Oxygenated Derivatives from Docosahexaenoic Acid in Rat Brain
Résumé
Docosahexaenoic acid (DHA), a prominent long-chain fatty acid of the omega-3 family, is present at high amount in brain tissues, especially in membrane phospholipids. This polyunsaturated fatty acid is the precursor of various oxygenated lipid mediators involved in diverse physiological and pathophysiological processes. Characterization of DHA-oxygenated metabolites is therefore crucial for better understanding the biological roles of DHA. In this study, we identified and measured, by ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry, a number of oxygenated products derived from DHA in exsanguinated and nonexsanguinated brains. These metabolites were found both in free form and esterified in phospholipids. Interestingly, both (R)- and (S)-monohydroxylated fatty acid stereoisomers were observed free and esterified in phospholipids. Monohydroxylated metabolites were the main derivatives; however, measurable amounts of dihydroxylated products such as protectin DX were detected. Moreover, exsanguination allowed discriminating brain oxygenated metabolites from those generated in blood. These results obtained in healthy rats allowed an overview on the brain oxygenated metabolism of DHA, which deserves further research in pathophysiological conditions, especially in neurodegenerative diseases.
Mots clés
activated
arachidonic-acid
Biochemistry & Molecular Biology
Brain
Docosanoids
Eicosanoids
focused microwave irradiation
human platelets
inflammation
ischemia
LC-MS
Lipid peroxidation
lipid-mediators
lipoxygenase
Lipoxygenation
metabolites
MS
Nutrition & Dietetics
polyunsaturated fatty-acids
protectin dx