Liquid chromatographic-mass spectrometric measurement of the endogenous cannabinoid 2-arachidonylgiycerol in the spinal cord and peripheral nervous system

AIM: To develop a sensitive method for measuring the putative endocannabino id 2-arachidonylglycerol (2-AG) in the peripheral and central nervous syste m. METHODS: A method using atmospheric pressure chemical ionization (APCI) liquid chromatography/mass spectrometry (LC/MS) was developed to determine the levels of 2-AG in methanol extracts of the rat lumbar spinal cord, dors al root ganglion (DRG), and sciatic nerve. RESULTS: 2-AG was detected with high sensitivity and minimal sample preparation. The levels in the tissues analyzed were less than or equal to pmol/mg wet weight. Similar levels were found in the spinal cord acid the DRG, whereas approximately 7-fold lower levels were observed in the sciatic nerve. CONCLUSION: 2-AG is present in t he peripheral nervous system, and the levels are markedly higher in cell bo dies than those in axons.