Mass spectrometric quantification of the mu opioid receptor agonist Tyr-D-Arg-Phe-Lys-NH2 (DALDA) in high-performance liquid chromatography-purified ovine plasma.
The mu opioid receptor agonist Tyr-D-Arg-Phe-Lys-Amide (D-Arg2-Lys4-Dermorphin(1-4)amide=DALDA) was infused continuously for 2 h into sheep. The presence of DALDA in ovine plasma was determined by reversed-phase high-performance liquid chromatography (RP-HPLC) and mass spectrometry (MS) in plasma samples that were obtained at different times during and following that infusion. A stable isotope-incorporated internal standard, deuterated DALDA (d5-DALDA), was used for the MS quantification of DALDA via the protonated molecule ion, (M+H)+, of DALDA and of d5-DALDA. Time-course data (microg DALDA ml(-1) plasma vs. time) were obtained. Tandem MS (MS-MS) provided the product-ion spectrum of the (M+H)+ ion of DALDA in one of the samples to confirm the amino acid sequence of DALDA.
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The Charles B. Stout Neuroscience Mass Spectrometry Laboratory, University of Tennessee, Memphis 38163, USA.
Tseng
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JL
Becklin
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Desiderio
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DM
D000700:Analgesics / Q000097:blood*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D005260:Female; D013058:Mass Spectrometry; D009842:Oligopeptides / Q000097:blood* / Q000737:chemistry; D011247:Pregnancy; D017450:Receptors, Opioid, mu / Q000819:agonists*; D015203:Reproducibility of Results; D012756:Sheep
D000700:Analgesics; D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C063076:tyrosyl-arginyl-phenylalanyl-lysinamide