AJP - Heart Calcium Transients and Cell-Sarcomere
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 294: H2069-H2077, 2008. First published February 29, 2008; doi:10.1152/ajpheart.01163.2007
0363-6135/08 $8.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
294/5/H2069    most recent
01163.2007v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Google Scholar
Right arrow Articles by de Beer, V. J.
Right arrow Articles by Merkus, D.
PubMed
Right arrow PubMed Citation
Right arrow Articles by de Beer, V. J.
Right arrow Articles by Merkus, D.

Integrative control of coronary resistance vessel tone by endothelin and angiotensin II is altered in swine with a recent myocardial infarction

Vincent J. de Beer,1 Oana Sorop,1 Daniël A. Pijnappels,1 Dick H. Dekkers,2 Frans Boomsma,3 Jos M. J. Lamers,2 Dirk J. Duncker,1 and Daphne Merkus1

1Division of Experimental Cardiology, Department of Cardiology, Thoraxcenter, 2Department of Biochemistry, and 3Department of Internal Medicine, Cardiovascular Research School Erasmus University Rotterdam, Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands

Submitted 8 October 2007 ; accepted in final form 26 February 2008

Several studies have indicated an interaction between the renin-angiotensin (ANG II) system and endothelin (ET) in the regulation of vascular tone. Previously, we have shown that both ET and ANG II exert a vasoconstrictor influence on the coronary resistance vessels of awake normal swine. Here, we investigated whether the interaction between ANG II and ET exists in the control of coronary resistance vessel tone at rest and during exercise using single and combined blockade of angiotensin type 1 (AT1) and ETA/ETB receptors. Since both circulating ANG II and ET levels are increased after myocardial infarction (MI), we investigated if the interaction between these systems is altered after MI. In awake healthy swine, coronary vasodilation in response to ETA/ETB receptor blockade in the presence of AT1 blockade was similar to vasodilation produced by ETA/ETB blockade under control conditions. In awake swine with a 2- to 3-wk-old MI, coronary vasodilator responses to individual AT1 and ETA/ETB receptor blockade were virtually abolished, despite similar coronary arteriolar AT1 and ETA receptor expression compared with normal swine. Unexpectedly, in the presence of AT1 blockade (which had no effect on circulating ET levels), ETA/ETB receptor blockade elicited a coronary vasodilator response. These findings suggest that in normal healthy swine the two vasoconstrictor systems contribute to coronary resistance vessel control in a linear additive manner, i.e., with negligible cross-talk. In contrast, in the remodeled myocardium, cross-talk between ANG II and ET emerges, resulting in nonlinear redundant control of coronary resistance vessel tone.

coronary blood flow; exercise; left ventricular remodeling; neurohormones; receptor


Address for reprint requests and other correspondence: D. Merkus, Div. of Experimental Cardiology, Thoraxcenter, Erasmus Medical Center, Univ. Medical Center Rotterdam, PO Box 2040, Rotterdam 3000 CA, The Netherlands (e-mail: d.merkus{at}erasmusmc.nl)






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2008 by the American Physiological Society.