Title
Liquid chromatography-tandem mass spectrometry analysis of free and esterified fatty acid N-acyl ethanolamines in plasma and blood cells
Author
Balvers, M.G.J.
Wortelboer, H.M.
Witkamp, R.F.
Verhoeckx, K.C.M.
Publication year
2013
Abstract
The origin of N-acyl ethanolamides (NAEs) in plasma is not well understood, and it is possible that NAEs are present in plasma in esterified form. To test this hypothesis, a new and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of arachidonoyl ethanolamide, 2-arachidonoyl glycerol, docosahexaenoyl ethanolamide, dihomo-γ-linolenoyl ethanolamide, oleoyl ethanolamide, palmitoyl ethanolamide, and stearoyl ethanolamide in 100 μl of human plasma using a simple acetonitrile extraction step. Using this method, we determined (i) free and esterified NAE levels in human plasma, (ii) free and esterified NAE levels in plasma of mice fed with diets with different amounts of n-3 fatty acids, and (iii) esterified NAE levels in blood cells. Murine and human plasma extracts contained 20- to 60-fold higher levels of esterified NAEs than free NAEs. Moreover, the effect of dietary n-3 fatty acids on murine free plasma NAE profiles was similar for esterified NAEs. Finally, esterified NAEs were also present in murine blood cells, and their pattern followed the same diet effect as observed for free and esterified NAEs in plasma. Together, these data point to the presence of previously ignored pools of esterified NAEs in plasma and blood cells that correlated well with free NAE levels in plasma. © 2012 Elsevier Inc. All rights reserved.
Subject
Life
QS - Quality & Safety PHS - Pharmacokinetics & Human Studies
EELS - Earth, Environmental and Life Sciences
Biomedical Innovation
Biology
Healthy Living
Diet
Endocannabinoids
LC-MS/MS
NAEs
Plasma
Validation
To reference this document use:
http://resolver.tudelft.nl/uuid:ef52c588-3cef-4b17-b7ef-0ed9362d2592
DOI
https://doi.org/10.1016/j.ab.2012.11.008
TNO identifier
470007
ISSN
0003-2697
Source
Analytical Biochemistry, 434 (2), 275-283
Document type
article