Pharmacological characterization of RMP-7, a novel bradykinin agonist in smooth muscle

Pharmacological characterization of RMP-7, a novel bradykinin agonist in smooth muscle

Author Shimuta, S. I. Google Scholar
Barbosa, AMRB Google Scholar
Borges, ACR Google Scholar
Paiva, T. B. Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract RMP-7 is a bradykinin (BK) agonist designed to be resistant to kininases such as angiotensin-converting enzyme (ACE). Pharmacological assays were performed with RMP-7 in isolated guinea-pig ileum and rat mesenteric artery. RMP-7 induced contractile responses in the guinea-pig ileum, where the apparent affinity of the peptide (pD(2)) was significantly lower than that determined for BK (7.3 +/- 0.07 vs. 8.3 +/- 0.05, respectively). HOE-140 blocked this effect indicating that B-2 receptor was involved. Captopril (1 mu M) had no potentiating effect on RMP-7 but increased pD(2) value determined for BK (8.8 +/- 0.1), confirming a high resistance of RMP-7 to the ACE. in rat mesenteric artery, RMP-7 induced endothelium-dependent relaxation (7.8 +/- 0.4), with a higher affinity than that of BK which induced vasodilatation only in the presence of 1 mu M captopril (6.9 +/- 0.36). Nevertheless, the maximum effect induced by RMP-7 was lower than that of BK in contrast to that observed in guinea-pig ileum although B-2 receptor was involved in both cases. We concluded that: RMP-7 is greatly resistant to the ACE and that the receptor sites activated by RMP-7 and BK show important differences in vascular and non-vascular preparations probably due to the different sensitivity of the B-2 receptor to RMP-7. (C) 1999 Elsevier Science B.V. All rights reserved.
Keywords bradykinin
B-2 receptors
angiotensin-converting enzyme
guinea-pig ileum
mesenteric artery
Language English
Date 1999-12-01
Published in Immunopharmacology. Amsterdam: Elsevier B.V., v. 45, n. 1-3, p. 63-67, 1999.
ISSN 0162-3109 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 63-67
Origin http://dx.doi.org/10.1016/S0162-3109(99)00150-2
Access rights Closed access
Type Article
Web of Science ID WOS:000084080100011
URI http://repositorio.unifesp.br/handle/11600/26193

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