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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
Author(s) -
RamírezMolina César,
Heudi Olivier,
Pullen Mark,
Marshall Peter S.
Publication year - 2006
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/psc.712
Subject(s) - bradykinin , chemistry , chromatography , mass spectrometry , membrane , metabolite , enzyme , biochemistry , receptor
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. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.