title: Estimation of reference intervals of five endocannabinoids and endocannabinoid related compounds in human plasma by two dimensional-LC/MS/MS.
abstract: The elucidation of the role of endocannabinoids in physiological and pathological conditions and the transferability of the importance of these mediators from basic evidence into clinical practice is still hampered by the indefiniteness of their circulating reference intervals. In this work, we developed and validated a two-dimensional LC/MS/MS method for the simultaneous measurement of plasma endocannabinoids and related compounds such as arachidonoyl-ethanolamide, palmitoyl-ethanolamide, and oleoyl-ethanolamide, belonging to the N-acyl-ethanolamide (NAE) family, and 2-arachidonoyl-glycerol and its inactive isomer 1-arachidonoyl-glycerol from the monoacyl-glycerol (MAG) family. We found that several pitfalls in the endocannabinoid measurement may occur, from blood withdrawal to plasma processing. Plasma extraction with toluene followed by on-line purification was chosen, allowing high-throughput and reliability. We estimated gender-specific reference intervals on 121 healthy normal weight subjects fulfilling rigorous anthropometric and hematic criteria. We observed no gender differences for NAEs, whereas significantly higher MAG levels were found in males compared with females. MAGs also significantly correlated with triglycerides. NAEs increased with age in females, and arachidonoyl-ethanolamide correlated with adiposity and metabolic parameters in females. This work paves the way to the establishment of definitive reference intervals for circulating endocannabinoids to help physicians move from the speculative research field into the clinical field.
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Flaminia
authors.initials: F
authors.lastname: Fanelli
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Valentina D
authors.initials: VD
authors.lastname: Di Lallo
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Belluomo
authors.affiliation: Central Laboratory, S.Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Rosaria
authors.initials: R
authors.lastname: De Iasio
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Margherita
authors.initials: M
authors.lastname: Baccini
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Elena
authors.initials: E
authors.lastname: Casadio
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Daniela Ibarra
authors.initials: DI
authors.lastname: Gasparini
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Colavita
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Gambineri
authors.affiliation: Central Laboratory, S.Orsola-Malpighi Hospital, Bologna, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Grossi
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Valentina
authors.initials: V
authors.lastname: Vicennati
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and.
authors.forename: Renato
authors.initials: R
authors.lastname: Pasquali
authors.affiliation: Endocrinology Unit, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and; Endocrinology Unit and Centre of Applied Biomedical Research, Department of Clinical Medicine, Alma Mater Studiorum, University of Bologna, Bologna, Italy; and. Electronic address: uberto.pagotto@unibo.it.
authors.forename: Uberto
authors.initials: U
authors.lastname: Pagotto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001095:Arachidonic Acids / Q000097:blood; D063385:Cannabinoid Receptor Modulators / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D063388:Endocannabinoids; D005260:Female; D005989:Glycerides / Q000097:blood; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D050178:Monoglycerides / Q000097:blood; D009829:Oleic Acids / Q000097:blood; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D063388:Endocannabinoids; D005989:Glycerides; D050178:Monoglycerides; D009829:Oleic Acids; C488250:oleoylethanolamide; C094503:glyceryl 2-arachidonate