Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS
Endocannabinoids and endocannabinoid-related compounds (ERCs) are involved in many physiological processes. They are released on demand from phosphoinositide and N-acylphosphatidyl ethanolamine (NAPE) precursors and comprise 2-monoacylglycerols (2-MGs) and FA ethanolamides (FEAs). Despite the abunda...
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| Format: | Article |
| Language: | English |
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Elsevier
2019-08-01
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| Series: | Journal of Lipid Research |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520322422 |
| _version_ | 1818384141330153472 |
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| author | Waldemar Röhrig Susanne Achenbach Birgit Deutsch Monika Pischetsrieder |
| author_facet | Waldemar Röhrig Susanne Achenbach Birgit Deutsch Monika Pischetsrieder |
| author_sort | Waldemar Röhrig |
| collection | DOAJ |
| description | Endocannabinoids and endocannabinoid-related compounds (ERCs) are involved in many physiological processes. They are released on demand from phosphoinositide and N-acylphosphatidyl ethanolamine (NAPE) precursors and comprise 2-monoacylglycerols (2-MGs) and FA ethanolamides (FEAs). Despite the abundance of advanced quantitative methods, however, their determined concentrations in blood plasma are inconsistent because 2-MGs and FEAs undergo artifactual de novo formation, chemical isomerization, and degradation during sample collection and storage. For a comprehensive survey of these compounds in blood and plasma, we have developed and validated an ultra-HPLC-MS/MS method to quantify 24 endocannabinoids, ERCs, and their phospholipid precursors. Immediate acidification of EDTA-blood to pH 5.8 blocked artifactual FEA formation for at least 4 h on ice. The 2-MGs were stabilized after plasma harvest with 0.5 M potassium thiocyanate at pH 4.7. FEA and MG plasma concentrations in six healthy volunteers ranged between 0.04–3.48 and 0.63–6.18 ng/ml, respectively. Interestingly, only 1–5% of circulating FEAs were present in their free form, while the majority was bound to NAPEs. Similarly, 97% of 2-arachidonoylglycerol (2-AG) was bound to a potential phosphoinositide pool. The herein-described stabilization and extraction methods may now be used to reliably and comprehensively quantify endocannabinoids, ERCs, and their phospholipid precursors in clinical studies. |
| first_indexed | 2024-12-14T03:17:32Z |
| format | Article |
| id | doaj.art-807e3e16a699407fa870945ece618c95 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-14T03:17:32Z |
| publishDate | 2019-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-807e3e16a699407fa870945ece618c952022-12-21T23:19:06ZengElsevierJournal of Lipid Research0022-22752019-08-0160814751488Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MSWaldemar Röhrig0Susanne Achenbach1Birgit Deutsch2Monika Pischetsrieder3To whom correspondence should be addressed.; Food Chemistry, Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, GermanyDepartment of Transfusion Medicine and Hemostaseology Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, GermanyInstitute of Experimental and Clinical Pharmacology and Toxicology Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, GermanyFood Chemistry, Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, GermanyEndocannabinoids and endocannabinoid-related compounds (ERCs) are involved in many physiological processes. They are released on demand from phosphoinositide and N-acylphosphatidyl ethanolamine (NAPE) precursors and comprise 2-monoacylglycerols (2-MGs) and FA ethanolamides (FEAs). Despite the abundance of advanced quantitative methods, however, their determined concentrations in blood plasma are inconsistent because 2-MGs and FEAs undergo artifactual de novo formation, chemical isomerization, and degradation during sample collection and storage. For a comprehensive survey of these compounds in blood and plasma, we have developed and validated an ultra-HPLC-MS/MS method to quantify 24 endocannabinoids, ERCs, and their phospholipid precursors. Immediate acidification of EDTA-blood to pH 5.8 blocked artifactual FEA formation for at least 4 h on ice. The 2-MGs were stabilized after plasma harvest with 0.5 M potassium thiocyanate at pH 4.7. FEA and MG plasma concentrations in six healthy volunteers ranged between 0.04–3.48 and 0.63–6.18 ng/ml, respectively. Interestingly, only 1–5% of circulating FEAs were present in their free form, while the majority was bound to NAPEs. Similarly, 97% of 2-arachidonoylglycerol (2-AG) was bound to a potential phosphoinositide pool. The herein-described stabilization and extraction methods may now be used to reliably and comprehensively quantify endocannabinoids, ERCs, and their phospholipid precursors in clinical studies.http://www.sciencedirect.com/science/article/pii/S0022227520322422fatty acid ethanolamide2-arachidonoylglycerol2-monoacylglycerolN-acylphosphatidyl ethanolaminephosphatidyl ethanolaminearachidonoyl phosphoinositide |
| spellingShingle | Waldemar Röhrig Susanne Achenbach Birgit Deutsch Monika Pischetsrieder Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS Journal of Lipid Research fatty acid ethanolamide 2-arachidonoylglycerol 2-monoacylglycerol N-acylphosphatidyl ethanolamine phosphatidyl ethanolamine arachidonoyl phosphoinositide |
| title | Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS |
| title_full | Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS |
| title_fullStr | Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS |
| title_full_unstemmed | Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS |
| title_short | Quantification of 24 circulating endocannabinoids, endocannabinoid-related compounds, and their phospholipid precursors in human plasma by UHPLC-MS/MS |
| title_sort | quantification of 24 circulating endocannabinoids endocannabinoid related compounds and their phospholipid precursors in human plasma by uhplc ms ms |
| topic | fatty acid ethanolamide 2-arachidonoylglycerol 2-monoacylglycerol N-acylphosphatidyl ethanolamine phosphatidyl ethanolamine arachidonoyl phosphoinositide |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520322422 |
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