Ca2+ entry mode of Na+/Ca2+ exchanger as a new therapeutic target for heart failure with preserved ejection fraction.
Eur Heart J
; 33(11): 1408-16, 2012 Jun.
Article
em En
| MEDLINE
| ID: mdl-21490055
ABSTRACT
AIMS:
Left ventricular (LV) fibrosis and stiffening play crucial roles in the development of heart failure with preserved ejection fraction (HFPEF). Plasma level of digitalis-like factors (DLFs) is increased in patients with hypertension, a principal underlying cardiovascular disease of HFPEF. Digitalis-like factors inhibit ion-pumping function of Na(+)/K(+)-ATPase and activate the Ca(2+) entry mode of Na(+)/Ca(2+) exchanger (NCX). Digitalis-like factors are known to promote collagen production in fibroblasts. The aim of this study was to explore whether the pharmacological inhibition of the NCX entry mode is effective in the prevention of LV fibrosis and in the development of HFPEF. METHODS ANDRESULTS:
(i) Dahl salt-sensitive rats fed 8% NaCl diet from age 6 weeks served as hypertensive HFPEF model. In this model, 24 h urine excretion of DLFs was greater than that in the age-matched control at compensatory hypertrophic and heart failure stages. (ii) Continuous administration of ouabain for 14 weeks developed LV fibrosis without affecting blood pressure in Sprague-Dawley rats. (iii) Ouabain elevated intracellular Ca(2+) concentration through the entry of extracellular Ca(2+), increased the phosphorylation level of p42/44 mitogen-activated protein kinases, and enhanced (3)H-proline incorporation in cardiac fibroblast; and SEA0400, the inhibitor of the NCX entry mode, suppressed these effects. (iv) In the HFPEF model, administration of SEA0400 at subdepressor dose improved the survival rate in association with the attenuation of LV fibrosis and stiffening.CONCLUSION:
Digitalis-like factors and the subsequently activated NCX entry mode may play an important role in the development of hypertensive HFPEF, and the blockade of the NCX entry mode may be a new therapeutic strategy for this phenotype of heart failure.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saponinas
/
Cardenolídeos
/
Cálcio
/
Trocador de Sódio e Cálcio
/
Insuficiência Cardíaca
/
Ventrículos do Coração
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Eur Heart J
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Japão