title: Matrix-assisted laser desorption/ionization mass spectrometric quantification of the mu opioid receptor agonist DAMGO in ovine plasma.
abstract: The synthetic opioid peptide analog Tyr-D-Ala-Gly-N-methyl-Phe-Gly-ol (DAMGO), which is a mu opioid receptor-selective agonist, was quantified in ovine plasma samples with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), using delayed extraction and a reflectron. The internal standard was pentadeuterated DAMGO. Timed-ion selection was used to select the precursor ion. The analysis of the post-source decay fragments improved the detection sensitivity, and the use of the precursor-product ion relationship optimized the specificity. For plasma samples, the inter-assay variability of this method was 6.4% (n = 79) and the intra-assay variability was 6.0% (n = 10). The variability for controls was 3.4% (n = 43). The profile of DAMGO amount versus time was determined in sheep plasma, and the corresponding pharmacokinetic data were calculated.
authors.affiliation: Charles B. Stout Neuroscience Mass Spectrometry Laboratory, Departments of Neurology and Biochemistry, University of Tennessee, Memphis, 847 Monroe Avenue, Memphis, Tennessee 38163, USA. ddesiderio@utmem.edu
authors.forename: D M
authors.initials: DM
authors.lastname: Desiderio
authors.forename: U
authors.initials: U
authors.lastname: Wirth
authors.forename: J L
authors.initials: JL
authors.lastname: Lovelace
authors.forename: G
authors.initials: G
authors.lastname: Fridland
authors.forename: E S
authors.initials: ES
authors.lastname: Umstot
authors.forename: T M
authors.initials: TM
authors.lastname: Nguyen
authors.forename: P W
authors.initials: PW
authors.lastname: Schiller
authors.forename: H S
authors.initials: HS
authors.lastname: Szeto
authors.forename: J F
authors.initials: JF
authors.lastname: Clapp
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D005260:Female; D007262:Infusions, Intravenous; D017450:Receptors, Opioid, mu / Q000819:agonists*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012756:Sheep; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data
chemical_list: D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-