Skip Navigation

Cardiovascular Research 1998 38(2):451-462; doi:10.1016/S0008-6363(98)00007-8
© 1998 by European Society of Cardiology
This Article
Right arrow Full Text Freely available
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 Ramñrez-Gil, J. F.
Right arrow Articles by Charlemagne, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ramñrez-Gil, J. F.
Right arrow Articles by Charlemagne, D.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1998, European Society of Cardiology

Modifications of myocardial Na+,K+-ATPase isoforms and Na+/Ca2+ exchanger in aldosterone/salt-induced hypertension in guinea pigs

Juan Fernando Ramñrez-Gila,c, Pascal Trouvéc, Nathalie Mougenota, Alain Carayonb, Philippe Lechata and Danièle Charlemagnec,*

aLaboratoire de Pharmacologie Cardiovasculaire, Service de Pharmocologie, IFR Génétique et Physiopathologie Cardiovasculaire, Hôpital Pitié-Salpêtrière, 47 Bd de l'Hôpital, 75651 Paris Cedex 13, France
bService de Biochimie, Faculté de Médecine Pitié-Salpêtrière, IFR Génétique et Physiopathologie Cardiovasculaire, Hôpital Pitié-Salpêtrière, Faculté de Médecine Pitié-Salpêtrière, 91 Bd de l'Hôpital, 75013 Paris Cedex 13, France
cINSERM-U127, Biologie et Physiopathologie du coeur et des vaisseaux, IFR Circulation Lariboisière, Université D. Diderot, 41 Bd de la Chapelle, 75475 Paris Cedex 10, France

* Corresponding author. Tel.: +33 (1) 4285 8065; Fax: +33 (1) 4874 2315; E-mail: daniele.charlemagne@inserm.lrb.ap-hop-paris.fr

Objective: The aim of this study was to determine whether changes in cardiac Na+,K+-ATPase subunits and Na+/Ca2+ exchanger expression are regulated in aldosterone-salt hypertensive guinea pigs. Methods: Guinea pigs (GP) were unilaterally nephrectomized and randomized into three groups (aldosterone-salt; control-salt; control). After 90 days of treatment, echocardiographic M-mode assessment and right carotid arterial catheterization were performed in vivo, and plasma hormones and electrolytes were measured. mRNA and protein levels were studied by Northern and Western blot analysis. Results: Aldosterone-salt treatment induced, (1) arterial hypertension (+40%) and LV hypertrophy (+60%) without altering LV-fractional shortening, (2) an increase in plasma norepinephrine levels (+262%) and suppression of renin activity. Northern blot analysis showed the presence of the mRNA encoding the three {alpha} isoforms and the β1 subunit of Na+,K+-ATPase in GP myocardium. In the aldosterone-salt group, levels of {alpha}1 and β1 mRNAs were unchanged. {alpha}2 mRNA was increased in both ventricles, whereas {alpha}3 mRNA was increased in hypertrophied LV only. Furthermore, levels of the Na+/Ca2+ exchanger mRNA were decreased in both ventricles. At protein level, the two major transcripts ({alpha}1 and {alpha}2) were detected but {alpha}3 isoform was not. Parallel changes in protein and mRNA accumulation of {alpha}1 and {alpha}2 isoforms were observed in hypertrophied LV. Conclusion: These results show that {alpha}1 and {alpha}2 isoforms are expressed in GP heart and that they are independently regulated in aldosterone-salt hypertension. Like the {alpha}1 isoform in renal tissue, {alpha}2 isoform is the main target of aldosterone-salt. Reciprocal expression of the Na+/Ca2+ exchanger and Na+,K+-ATPase suggests an adaptational mechanism which maintains an appropriate sodium gradient and calcium concentration in hypertensive myocardium.

KEYWORDS Aldosterone; Na+,K+-ATPase; Na+/Ca2+ exchanger; Hypertension; Heart; Guinea pigs


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
P. Fransen, J. Hendrickx, D. L Brutsaert, and S. U Sys
Distribution and role of Na+/K+ ATPase in endocardial endothelium
Cardiovasc Res, December 1, 2001; 52(3): 487 - 499.
[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.