pubmed:abstractText |
The N-terminal sequence of icatibant, a widely used peptide antagonist of the bradykinin B(2) receptors, is analogous to that of other known aminopeptidase N inhibitors. Icatibant competitively inhibited the hydrolysis of L-Ala-p-nitroanilide by recombinant aminopeptidase N (K(i) 9.1 microM). In the rabbit aorta, icatibant (10-30 microM) potentiated angiotensin III, but not angiotensin II (contraction mediated by angiotensin AT(1) receptors), and Lys-des-Arg(9)-bradykinin, but not des-Arg(9)-bradykinin (effects mediated by the bradykinin B(1) receptors), consistent with the known susceptibility of these agonists to aminopeptidase N. At concentrations possibly reached in vivo (e.g., in kidneys), icatibant alters physiological systems different from bradykinin B(2) receptors.
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