|
|
||||||||
1Department of Cell Biology, University of Calabria, Arcavacata di Rende, Italy; and 2Department of Medicine, University of California and Veterans Affairs San Diego Healthcare System, San Diego, California
Submitted 18 February 2008 ; accepted in final form 2 May 2008
The catecholamine release-inhibitory catestatin [Cts; human chromogranin (Cg) A352-372, bovine CgA344-364] is a vasoreactive and anti-hypertensive peptide derived from CgA. Using the isolated avascular frog heart as a bioassay, in which the interactions between the endocardial endothelium and the subjacent myocardium can be studied without the confounding effects of the vascular endothelium, we tested the direct cardiotropic effects of bovine Cts and its interaction with β-adrenergic (isoproterenol, ISO) and endothelin-1 (ET-1) signaling. Cts dose-dependently decreased stroke volume and stroke work, with a threshold concentration of 11 nM, approaching the in vivo level of the peptide. Cts reduced contractility by inhibiting phosphorylation of phospholamban (PLN). Furthermore, the Cts effect was abolished by pretreatment with either nitric oxide synthase (NG-monomethyl-L-arginine) or guanylate cyclase (ODQ) inhibitors, or an ETB receptor (ETBR) antagonist (BQ-788). Cts also noncompetitively inhibited the positive inotropic action of ISO. In addition, Cts inhibited the positive inotropic effect of ET-1, mediated by ETA receptors, and did not alter the negative inotropic ET-1 influence mediated by ETBR. Cts action through ETBR was further suggested when, in the presence of BQ-788, Cts failed to inhibit the positive inotropism of both ISO and ET-1 stimulation and PLN phosphorylation. We concluded that the cardiotropic actions of Cts, including the β-adrenergic and ET-1 antagonistic effects, support a novel role of this peptide as an autocrine-paracrine modulator of cardiac function, particularly when the stressed heart becomes a preferential target of both adrenergic and ET-1 stimuli.
chromogranin A; myocardial contractility; inotropic agents; avascular heart; endocardial endothelium
This article has been cited by other articles:
![]() |
K. B. Helle The chromogranin A-derived peptides vasostatin-I and catestatin as regulatory peptides for cardiovascular functions Cardiovasc Res, August 18, 2009; (2009) cvp266v2. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |