title: Simultaneous tissue profiling of eicosanoid and endocannabinoid lipid families in a rat model of osteoarthritis.
abstract: We describe a novel LC method for the simultaneous and quantitative profiling of 43 oxylipins including eicosanoids, endocannabinoids, and structurally related bioactive lipids with modified acyl groups. The LC-MS/MS method uses switching at a defined time between negative and positive electrospray ionization modes to achieve optimal detection sensitivity for all the lipids. The validated method is linear over a range of 0.01-5 nmol/g (0.1-50 nmol/g for 2-arachidonoyl glycerol) with intra- and interday precision and accuracy between 1.38 and 26.76% and 85.22 and 114.3%, respectively. The method successfully quantified bioactive lipids in different tissue types in the rat, including spinal cord, dorsal root ganglia (DRGs), knee joint, brain, and plasma. Distinct regional differences in the pattern of lipid measured between tissue types were observed using principle component analysis. The method was applied to analyze tissue samples from an established preclinical rat model of osteoarthritis (OA) pain and showed that levels of 12-hydroxyeicosatetraenoic acid were significantly increased in the OA rat knee joint compared with controls, and that 15-hydroxyeicosatetraenoic acid was significantly increased in the DRGs in the model of OA compared with controls. The developed LC-MS/MS method has the potential to provide detailed pathway profiling in tissues and biofluids where the disruption of bioactive oxylipins may be involved in disease states.
authors: Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham NG7 2UH, UK.
authors: Amy
authors: A
authors: Wong
authors: School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK Arthritis Research UK Pain Centre, University of Nottingham, Nottingham NG7 2UH, UK.
authors: Devi R
authors: DR
authors: Sagar
authors: Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham NG7 2UH, UK.
authors: Catharine A
authors: CA
authors: Ortori
authors: School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK.
authors: David A
authors: DA
authors: Kendall
authors: School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK Arthritis Research UK Pain Centre, University of Nottingham, Nottingham NG7 2UH, UK.
authors: Victoria
authors: V
authors: Chapman
authors: Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, Nottingham NG7 2UH, UK.
authors: David A
authors: DA
authors: Barrett
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D063388:Endocannabinoids / Q000378:metabolism*; D005727:Ganglia, Spinal / Q000378:metabolism; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism*; D007719:Knee Joint / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D009928:Organ Specificity; D020370:Osteoarthritis, Knee / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D063388:Endocannabinoids; D006893:Hydroxyeicosatetraenoic Acids; C095123:15-hydroxyeicosatrienoic acid
keywords: blood plasma; brain regions; knee; lipidomics; mass spectrometry; metabolic profiling