Influence of Long-Term Salt Diets on Cardiac Ca2+ Handling and Contractility Proteins in Hypertensive Rats.
Am J Hypertens
; 31(6): 726-734, 2018 05 07.
Article
in En
| MEDLINE
| ID: mdl-29518186
ABSTRACT
BACKGROUND:
High sodium intake contributes to the pathogenesis of hypertension and adversely affects cardiac function. Conversely, sodium reduction is associated with a blood pressure decrease and improved cardiovascular function. However, the mechanisms that underlie the cardiac effects induced by salt intake in hypertension have not been fully elucidated. Ca2+ handling is critical for efficient myocardial function; thus, we aimed to investigate the long-term effects of diets with different salt contents on cardiac function and Ca2+ handling proteins in spontaneously hypertensive rats (SHRs).METHODS:
Cardiac function was evaluated by catheterization. Ca2+ handling and contractile proteins were evaluated by immunoblotting in hearts from SHRs fed for 6 months with diets containing high (HS, 3%), low (LS, 0.03%), or normal salt content (NS, 0.3%). Diets were introduced immediately after weaning. Tail cuff pletismography was assessed at the 3rd and 7th months of follow-up.RESULTS:
Compared to the NS group, the HS group exhibited worsened hypertension, increased cardiac expression of ß-myosin heavy chain (MHC), a decreased α/ß-MHC ratio and reduced expression of both phospholamban (PLB) and Na+/Ca2+ exchanger (NCX). LS intake attenuated the blood pressure increase and left ventricle hypertrophy, slightly decreased the cardiac contractility and relaxation index, and increased the α/ß-MHC ratio. These effects were accompanied by increased cardiac PLB expression and decreased Ca2+ L-type channel and NCX expression.CONCLUSIONS:
These findings indicate that the modulation of Ca2+ handling may be one of the molecular mechanisms underlying the effect of salt intake on myocardial function in hypertension.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ventricular Function, Left
/
Sodium Chloride, Dietary
/
Calcium Signaling
/
Diet, Sodium-Restricted
/
Hypertension
/
Muscle Proteins
/
Myocardial Contraction
/
Myocardium
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Am J Hypertens
Journal subject:
ANGIOLOGIA
Year:
2018
Document type:
Article
Affiliation country:
Brasil