title: Metabolism of peptide YY 3-36 in Göttingen mini-pig and rhesus monkey.
abstract: Peptide YY 3-36-amide (PYY3-36) is a peptide hormone, which is known to decrease appetite and food-intake by activation of the Y2 receptor. The current studies were designed to identify the metabolites of PYY3-36 in mini-pig and rhesus monkey. Plasma samples were analyzed by high resolution LC-MS (and MS/MS) in order to unambiguously identify the metabolites of PYY3-36. In summary, the metabolism of PYY3-36 was similar in mini-pig and rhesus monkey. Several metabolites were identified and PYY3-34 was identified at the highest levels in plasma. In addition, mini-pigs were also dosed with PYY1-36-amide, PYY3-35, PYY3-34 and [N-methyl 34Q]-PYY3-36-amide in order to investigate the mechanisms by which PYY was metabolized. PYY3-35 was rapidly converted to PYY3-34 whereas dosing of PYY3-34 to mini-pigs only showed circulating degradation products at low levels, i.e., PYY3-34 was metabolically more stable than PYY3-36 and PYY3-35. [N-methyl 34Q]-PYY3-36-amide was hypothesized to be stable toward cleavage between 34Q and 35R and after i.v. administration to mini-pigs, one major cleavage product was identified as [N-methyl 34Q]-PYY3-35. Overall, this showed that cleavage between 35R and 36Y was possible as well as between 34Q and 35R (as shown for PYY3-35), which indicated that metabolism of PYY3-36 to PYY3-34 may be a two-step process. PYY1-36 was also dosed to mini-pigs, which showed that PYY1-36 was metabolized in the C-terminal as PYY3-36. The overall degradation pattern of PYY1-36 was more complex due to the simultaneous enzymatic degradation in the N-terminal to form PYY2-34/36 and PYY3-34/36. In vitro incubations with heparin stabilized plasma showed that PYY3-36 was degraded with a half-life of 175 min, whereas incubations with PYY3-35 (half-life of 6 min) showed a rapid formation of PYY3-34. In conclusion, the present studies showed that PYY3-36 underwent enzymatic degradation in the C-terminal part and that the major circulating metabolite was PYY3-34. Furthermore, it may be a sequential two-step process leading to the formation of PYY3-35 and subsequently the metabolically more stable PYY3-34.
authors.affiliation: Discovery ADME, Novo Nordisk A/S, Måløv, Denmark. Electronic address: jqgo@novonordisk.com.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Olsen
authors.affiliation: Protein & Peptide Chemistry 3, Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Kofoed
authors.affiliation: Protein & Peptide Chemistry 2, Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Østergaard
authors.affiliation: Diabetes & Obesity Biology, Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Birgitte S
authors.initials: BS
authors.lastname: Wulff
authors.affiliation: Pharmacology 2, Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Flemming S
authors.initials: FS
authors.lastname: Nielsen
authors.affiliation: Histology & Diabetes Pharmacology Novo Nordisk A/S, Måløv, Denmark.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Jorgensen
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects; D001711:Biotransformation; D002853:Chromatography, Liquid; D004435:Eating / Q000187:drug effects; D005260:Female; D006207:Half-Life; D008253:Macaca mulatta; D008297:Male; D010446:Peptide Fragments / Q000008:administration & dosage / Q000097:blood*; D019894:Peptide YY / Q000008:administration & dosage / Q000097:blood*; D059748:Proteolysis; D017476:Receptors, Neuropeptide Y / Q000378:metabolism; D013552:Swine; D013556:Swine, Miniature; D053719:Tandem Mass Spectrometry
chemical_list: D010446:Peptide Fragments; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor; D019894:Peptide YY; C061785:peptide YY (3-36)
keywords: In vivo metabolism; Liquid chromatography mass spectrometry (LC–MS); PYY(3–36)