Document Detail


Myocardial fibrosis, impaired coronary hemodynamics, and biventricular dysfunction in salt-loaded SHR.
MedLine Citation:
PMID:  16299266     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Arterial pressure in most experimental and clinical hypertensions is exacerbated by salt. The effects of salt excess on right and left ventricular (RV and LV, respectively) functions and their respective coronary vasodilatory responses have been less explored. We therefore examined the effects of 8 wk of NaCl excess (8% in food) on arterial pressure, RV and LV functions (maximal rate of increase and decrease of ventricular pressure; dP/dt(max) and dP/dt(min)), coronary hemodynamics (microspheres), and collagen content (hydroxyproline assay and collagen volume fraction) in young adult normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR), aged 16 wk by the end of the study. Prolonged salt excess in WKY and SHR elevated pressure only modestly, but it markedly increased LV mass, especially in SHR. Moreover, salt excess significantly impaired RV and LV diastolic function in SHR but only LV diastolic function in WKY rats. However, salt loading affected neither RV nor LV contractile function in both strains. Interstitial and perivascular collagen deposition was increased, whereas coronary vasodilatory responses to dipyridamole diminished in both ventricles in the salt-loaded SHR but not in WKY rats. Therefore, accumulation of ventricular collagen as well as altered myocardial perfusion importantly contributed to the development of salt-related RV and LV dysfunctions in this model of naturally occurring hypertension. The unique effects of salt loading on both ventricles in SHR, but not WKY rats, strongly suggest that nonhemodynamic mechanisms in hypertensive disease participate pathophysiologically with salt-loading hypertension. These findings point to the conclusion that the concept of "salt sensitivity" in hypertension is far more complex than simply its effects on arterial pressure or the LV.
Authors:
Jasmina Varagic; Edward D Frohlich; Javier Díez; Dinko Susic; Jwari Ahn; Arantxa González; Begoña López
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2005-11-18
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  290     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2006 Apr 
Date Detail:
Created Date:  2006-03-15     Completed Date:  2006-05-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H1503-9     Citation Subset:  IM    
Affiliation:
Hypertension Research Laboratory, Ochsner Clinic Foundation, New Orleans, LA 70121, USA. jvaragic@ochsner.org
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects
Coronary Circulation / drug effects
Coronary Disease / chemically induced,  physiopathology*
Endomyocardial Fibrosis / chemically induced,  physiopathology*
Hypertension / chemically induced*,  physiopathology*
Male
Rats
Rats, Inbred SHR
Sodium Chloride, Dietary / adverse effects*
Stroke Volume / drug effects
Ventricular Dysfunction / chemically induced,  physiopathology*
Chemical
Reg. No./Substance:
0/Sodium Chloride, Dietary

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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