title: Study of bradykinin metabolism by rat lung tissue membranes and rat kidney brush border membranes by HPLC with inductively coupled plasma-mass spectrometry and orthogonal acceleration time-of-flight mass spectrometry.
abstract: The coupling of the techniques, high-performance liquid chromatography (HPLC), orthogonal acceleration time-of-flight mass spectrometry (OATOF-MS) and inductively coupled plasma mass spectrometry (ICP-MS) provides a very powerful method for identifying and quantifying the products of bradykinin metabolism. In this study, we were able to identify the major metabolites of bradykinin degradation reported in the literature. In addition, a new bradykinin metabolite corresponding to bradykinin 5,9 fragment (BK-(5,9)-fragment) was identified as a product of neutral endopeptidase (NEP) activity. This finding establishes that NEP cleaves bradykinin simultaneously at the positions 4-5 and 7-8. We also demonstrate the equivalent participation of NEP and angiotensin-converting enzyme (ACE) within the rat lung tissue membranes (RLTM) in bradykinin degradation, suggesting its suitability as a model for the assay of dual ACE/NEP inhibitors. On the contrary, in rat kidney brush border membranes (KBBM), ACE is not significantly involved in bradykinin metabolism, with NEP being the major enzyme.
authors.affiliation: GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts. SG1 2NY, UK.
authors.forename: César
authors.initials: C
authors.lastname: Ramírez-Molina
authors.forename: Olivier
authors.initials: O
authors.lastname: Heudi
authors.forename: Mark
authors.initials: M
authors.lastname: Pullen
authors.forename: Peter S
authors.initials: PS
authors.lastname: Marshall
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000737:chemistry / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D007668:Kidney / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D008168:Lung / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D008871:Microvilli / Q000378:metabolism; D015260:Neprilysin / Q000037:antagonists & inhibitors / Q000737:chemistry; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship; D013841:Thiazepines / Q000494:pharmacology; D013997:Time Factors
chemical_list: D011725:Pyridines; D013841:Thiazepines; C106266:omapatrilat; D007703:Peptidyl-Dipeptidase A; D015260:Neprilysin; D001920:Bradykinin