title: Investigation of the metabolism of substance P at the blood-brain barrier using LC-MS/MS.
abstract: Substance P (SP) has been associated with pain and depression as well as neurodegenerative diseases. Many of these diverse actions of SP can potentially be attributed to SP metabolites generated at the blood-brain barrier (BBB). In this study, the metabolism of SP was investigated using an in vitro model of the BBB and LC-MS/MS. Substance P metabolism was found to be non-saturable in the concentration range of 100 nM to 10 microM, with approximately 70% of the peptide remaining intact after 5 h. The major metabolites of SP were identified by MS as 3-11 and 5-11. Two previously unreported metabolites, 5-11 and 6-11, were also found in our studies. Several additional minor SP metabolites, including 1-9 and 2-11, were also identified. A profile of the SP metabolites generated by the BBB over time was obtained. The results from the present study provide a better understanding of the role of the blood-brain barrier in the pharmacology of SP.
authors.affiliation: Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, USA.
authors.forename: Arvind K
authors.initials: AK
authors.lastname: Chappa
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Cooper
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Audus
authors.forename: Susan M
authors.initials: SM
authors.lastname: Lunte
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D001921:Brain / Q000098:blood supply / Q000378:metabolism*; D002199:Capillary Permeability; D002417:Cattle; D002478:Cells, Cultured; D002853:Chromatography, Liquid / Q000379:methods*; D042783:Endothelial Cells / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods*; D013373:Substance P / Q000378:metabolism*
chemical_list: D013373:Substance P