title: Proteomics tools reveal startlingly high amounts of oxytocin in plasma and serum.
abstract: The neuropeptide oxytocin (OT) is associated with a plethora of social behaviors, and is a key topic at the intersection of psychology and biology. However, tools for measuring OT are still not fully developed. We describe a robust nano liquid chromatography-mass spectrometry (nanoLC-MS) platform for measuring the total amount of OT in human plasma/serum. OT binds strongly to plasma proteins, but a reduction/alkylation (R/A) procedure breaks this bond, enabling ample detection of total OT. The method (R/A + robust nanoLC-MS) was used to determine total OT plasma/serum levels to startlingly high concentrations (high pg/mL-ng/mL). Similar results were obtained when combining R/A and ELISA. Compared to measuring free OT, measuring total OT can have advantages in e.g. biomarker studies.
authors.affiliation: Department of Chemistry, University of Oslo, Post Box 1033, Blindern, NO-0315 Oslo, Norway.
authors.forename: Ole Kristian
authors.initials: OK
authors.lastname: Brandtzaeg
authors.affiliation: Department of Chemistry, University of Oslo, Post Box 1033, Blindern, NO-0315 Oslo, Norway.
authors.forename: Elin
authors.initials: E
authors.lastname: Johnsen
authors.affiliation: Department of Chemistry, University of Oslo, Post Box 1033, Blindern, NO-0315 Oslo, Norway.
authors.forename: Hanne
authors.initials: H
authors.lastname: Roberg-Larsen
authors.affiliation: School of Pharmacy, University of Oslo, PO Box 1068, Blindern, NO-0316, Oslo, Norway.
authors.forename: Knut Fredrik
authors.initials: KF
authors.lastname: Seip
authors.affiliation: Department of Evolutionary Anthropology, Duke University, Durham, NC, 27708, USA.|School of Anthropology, University of Arizona, Tucson, AZ, 85721, USA.
authors.forename: Evan L
authors.initials: EL
authors.lastname: MacLean
authors.affiliation: Department of Biology, Duke University, Durham, NC, 27708, USA.
authors.forename: Laurence R
authors.initials: LR
authors.lastname: Gesquiere
authors.affiliation: Department of Psychology, University of Oslo, PO Box 1094, Blindern, NO-0317, Oslo Norway.|The Intervention Centre, Oslo University Hospital, PO Box 4950, Nydalen, NO-0424 Oslo, Norway.
authors.forename: Siri
authors.initials: S
authors.lastname: Leknes
authors.affiliation: Department of Chemistry, University of Oslo, Post Box 1033, Blindern, NO-0315 Oslo, Norway.
authors.forename: Elsa
authors.initials: E
authors.lastname: Lundanes
authors.affiliation: Department of Chemistry, University of Oslo, Post Box 1033, Blindern, NO-0315 Oslo, Norway.
authors.forename: Steven Ray
authors.initials: SR
authors.lastname: Wilson
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D010121:Oxytocin / Q000097:blood*; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D010121:Oxytocin