Skip Navigation

Cardiovascular Research 1996 31(1):157-162; doi:10.1016/S0008-6363(95)00188-3
© 1996 by European Society of Cardiology
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Irlbeck, M.
Right arrow Articles by Zimmer, H.-G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Irlbeck, M.
Right arrow Articles by Zimmer, H.-G.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1996, European Society of Cardiology

Different response of the rat left and right heart to norepinephrine

M. Irlbeck*, O. Mühling, T. Iwai and H.-G. Zimmer

Department of Physiology, University of Munich, Munich, Germany

* Corresponding author. Physiologisches Institut, Pettenkoferstrasse 12, 80336 München, Germany. Tel. (+49-89) 5996 383; Fax. (+49-89) 5996 378.

The in vivo hemodynamic and morphologic responses of the rat left (LV) and right (RV) ventricle to continuous long-term i.v. infusion of norepinephrine (NE) at different dosages and for different durations of infusion were studied. Female Sprague-Dawley rats received continuous intravenous infusion of norepinephrine from infors® syringe pumps for 24, 48 and 72 h at a dose of 200 µg · kg–1 · h–1. Furthermore, NE was infused for 72 h at dosages of 50, 100 and 200 µg · kg–1 · h–1. The beta-adrenergic blocker and vasodilator with alpha1-blocking activity carvedilol (0.5 mg · kg–1 · h–1) was coinfused with NE for 72 h. The hemodynamic effects were measured on intact, anesthetized rats with special Millar® ultraminiature pressure tip catheters, and the weights of the left and right ventricles were measured. NE increased heart rate at any time or dose, whereas cardiac output and total peripheral resistance remained unchanged. LV and RV dP/dtmax were nearly doubled as compared to control values and RVSP was elevated by more than 100%. The effect of NE on LVSP was much less pronounced (<20%) and only significant at 50 µg · kg–1 · h–1 for 72 h. Neither LV nor RV end-diastolic pressures were elevated, indicating that cardiac failure had not occurred. The LV developed hypertrophy with an increase of the ventricular weight/body weight ratio (LVW/BW) of 22% even after only 2 days of NE (200 µg · kg–1 · h–1). The RV showed no hypertrophy at any time of the experiments. The NE-induced changes in HR, dP/dtmax, RVSP and LVW/BW were completely prevented by the coinfusion of carvedilol. These studies show that the hemodynamic responses to continuous infusion of NE are more pronounced in the RV than in the LV. Conversely, NE induced hypertrophy only in the LV, not in the RV. The hemodynamic effects of chronic NE infusion did not change significantly between 1 and 3 days of infusion. The in vivo responses to exogenous NE therefore were unaffected by adaptive effects such as downregulation of adrenergic receptors.

KEYWORDS Norepinephrine; Rats; Cardiac hypertrophy; Right ventricle; Left ventricle


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Cardiovasc ResHome page
W. Briest, A. Holzl, B. Rassler, A. Deten, M. Leicht, H. A. Baba, and H.-G. Zimmer
Cardiac remodeling after long term norepinephrine treatment in rats
Cardiovasc Res, November 1, 2001; 52(2): 265 - 273.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.