(Circulation. 1995;92:2666-2675.)
© 1995 American Heart Association, Inc.
Articles |
From the Department of Pharmacology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan.
Correspondence to Satoshi Takeo, PhD, Department of Pharmacology, Tokyo University of Pharmacy and Life Science, 1432-1, Horinouchi, Hachioji, Tokyo, 192-03 Japan.
Background Cardiac contractile force in response to ß-adrenoceptor agonists and ß-adrenergic receptor density are decreased in failing human hearts. The effects of angiotensin Iconverting enzyme (ACE) inhibitor on cardiac responsiveness to ß-adrenergic stimulation in failing hearts are not established. The present study was undertaken to determine whether ACE inhibitor may improve cardiac ß-adrenergic responsiveness in animals with chronic heart failure (CHF).
Methods and Results CHF was induced by left coronary artery ligation in rats. Cardiac output and stroke volume indices decreased 12 weeks after the operation. In sham-operated rats, dobutamine and isoprenaline increased cardiac output and stroke volume indices. In contrast, cardiac output and stroke volume responses to dobutamine and isoprenaline were severely blunted in the CHF rat. Cardiac ß1-adrenergic receptor density was decreased while its dissociation constant (Kd) was not altered in the viable tissue of the left ventricle of the CHF rat, which is consistent with ß-adrenergic receptor downregulation. Cardiac norepinephrine content decreased in the CHF rats. Rats were treated orally with ACE inhibitors, 3 mg/kg trandolapril or 10 mg/kg enalapril once daily, or 5 mg/kg captopril twice daily from the 2nd to the 12th weeks after the operation. Treatment with ACE inhibitors attenuated the reduction in cardiac output and stroke volume indices and improved the inotropic response to dobutamine and isoprenaline and reversed partially the cardiac norepinephrine content in the CHF rat. ACE inhibitor treatment also attenuated the reduction in ß1-adrenergic receptor density in the viable tissue of the left ventricle of the CHF rat.
Conclusions The results suggest that ACE inhibitor treatment attenuates the blunting of cardiac responses to ß-adrenergic agonists in the CHF rat and that one of the mechanisms underlying this effect is prevention of cardiac ß1-adrenergic receptor downregulation.
Key Words: angiotensin receptors, adrenergic, beta heart failure
This article has been cited by other articles:
![]() |
N. S. Dhalla, M. R. Dent, P. S. Tappia, R. Sethi, J. Barta, and R. K. Goyal Subcellular Remodeling as a Viable Target for the Treatment of Congestive Heart Failure Journal of Cardiovascular Pharmacology and Therapeutics, March 1, 2006; 11(1): 31 - 45. [Abstract] [PDF] |
||||
![]() |
T. Makino, Y. Hattori, N. Matsuda, H. Onozuka, I. Sakuma, and A. Kitabatake Effects of Angiotensin-Converting Enzyme Inhibition and Angiotensin II Type 1 Receptor Blockade on beta -Adrenoceptor Signaling in Heart Failure Produced by Myocardial Infarction in Rabbits: Reversal of Altered Expression of beta -Adrenoceptor Kinase and Gialpha J. Pharmacol. Exp. Ther., January 1, 2003; 304(1): 370 - 379. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Yoshida, K. Tanonaka, Y. Miyamoto, T. Abe, M. Takahashi, M. B Anand-Srivastava, and S. Takeo Characterization of cardiac myocyte and tissue {beta}-adrenergic signal transduction in rats with heart failure Cardiovasc Res, April 1, 2001; 50(1): 34 - 45. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Witte, K. Hu, J. Swiatek, C. Mussig, G. Ertl, and B. Lemmer Experimental heart failure in rats: effects on cardiovascular circadian rhythms and on myocardial {beta}-adrenergic signaling Cardiovasc Res, August 1, 2000; 47(2): 350 - 358. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Igawa, T. Nozawa, N. Yoshida, N. Fujii, M. Inoue, S. Tazawa, H. Asanoi, and H. Inoue Heterogeneous cardiac sympathetic innervation in heart failure after myocardial infarction of rats Am J Physiol Heart Circ Physiol, April 1, 2000; 278(4): H1134 - H1141. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Yonemochi, S. Yasunaga, Y. Teshima, T. Iwao, K. Akiyoshi, M. Nakagawa, T. Saikawa, and M. Ito Mechanism of ß-Adrenergic Receptor Upregulation Induced by ACE Inhibition in Cultured Neonatal Rat Cardiac Myocytes : Roles of Bradykinin and Protein Kinase C Circulation, June 9, 1998; 97(22): 2268 - 2273. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Bohm, O. Zolk, M. Flesch, F. Schiffer, P. Schnabel, J.-P. Stasch, and A. Knorr Effects of Angiotensin II Type 1 Receptor Blockade and Angiotensin-Converting Enzyme Inhibition on Cardiac ß-Adrenergic Signal Transduction Hypertension, March 1, 1998; 31(3): 747 - 754. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1995 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |