Quantification of endocannabinoids 2-AG and AEA in animal organs and human fluids by GC/MS/MS

Wednesday, November 06, 2013 — Poster Session I
4:00 p.m. – 6:00 p.m.	FAES Academic Center (Upper-Level Terrace)	NIAAA	NEURO-22

Authors

Y.H. Lin
A.R. Alvheim
N.M. Salem
J.D. Loewke
A.W. Baca
A. Macherone
J.R. Hibbeln

Abstract

The endocannabinoids (EC) 2-arachidonoylglycerol (2-AG) and anandamide (AEA) are important bioactive lipids which share a common carbon chain backbone with the essential fatty acid, arachidonic acid. However, these EC’s are present only in low amounts and are highly unstable in available human samples and animal tissues, making quantification of 2-AG and AEA in vivo a challenging task. A stable isotope dilution analysis, that was coupled with mass spectrometry, was developed and validated for animal liver and brain. Lipids in organs were extracted by Folch method and trimethylsilylated by TBT reagents. An Agilent 7890A GC and 7000A GC/MS Triple Quad were employed for data acquisition. The product ions from the precursor ions of the analyte of interest were carried out and quantitated using multiple reactions monitoring. This method was applied in the quantification of 2-AG, AEA, and 2-AG’s isomer 1-AG in animal tissues in these studies, demonstrating that the elevation of dietary linoleic acid elevates endogenous 2-AG and AEA, and induces adiposity in mice and salmon. 2-AG was detected in human cerebrospinal fluid at very low quantities but AEA was not. 2-AG, AEA, and 1-AG were detected in human plasma and whole blood.