Cardiac mast cell proteases do not contribute to the regulation of the rat coronary vascular responsiveness to arterial delivered angiotensin I and II.

Autor: Bispo-da-Silva LB; Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil., Sivieri DO Jr, Prado CM, Becari C, Stuckert-Seixas SR, Pereira HJ, Rossi MA, Oliveira EB, Salgado MC
Jazyk: angličtina
Zdroj: Vascular pharmacology [Vascul Pharmacol] 2010 Jul-Aug; Vol. 53 (1-2), pp. 22-7. Date of Electronic Publication: 2010 Mar 19.
DOI: 10.1016/j.vph.2010.03.001
Abstrakt: Cardiac mast cells (MC) are apposed to capillaries within the heart and release renin and proteases capable of metabolizing angiotensins (Ang). Therefore, we hypothesized that mast cell degranulation could alter the rat coronary vascular responsiveness to the arterial delivered Ang I and Ang II, taking into account carboxypeptidase and chymase-1 activities. Hearts from animals that were either pretreated or not with systemic injection of the secretagogue compound 48/80 were isolated and mounted on a Langendorff apparatus to investigate coronary reactivity. The proteolytic activity of the cardiac perfusate from isolated hearts, pretreated or not with the secretagogue, toward Ang I and tetradecapeptide renin substrate was analyzed by HPLC. Coronary vascular reactivity to peptides was not affected by compound 48/80 pretreatment, despite the extensive amount of cardiac MC degranulation. Cardiac MC activation did not modify the generation of both Ang II and Ang 5-10 from Ang I by cardiac perfusate, activities that could be ascribed to MC carboxypeptidase and chymase-1, respectively. An aliskiren-resistant Ang I-forming activity was increased in perfusates from secretagogue-treated hearts. Thus, cardiac MC proteases capable of metabolizing angiotensins do not affect rat coronary reactivity to arterial delivered Ang I and II.
(Copyright 2010 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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