Development of heart failure following isoproterenol administration in the rat: role of the renin-angiotensin system.
Cardiovasc Res
; 37(1): 91-100, 1998 Jan.
Article
en En
| MEDLINE
| ID: mdl-9539862
ABSTRACT
OBJECTIVE:
High dosages of catecholamines induce cardiomyocyte necrosis and interstitial fibrosis in rats. We investigated whether this initial damage is followed by the development of heart failure and assessed the particular role of the renin-angiotensin system using ramipril. METHODS ANDRESULTS:
Following the administration of 0 mg or 150 mg isoproterenol/kg 6 groups of Wistar rats were followed for 2 or 16 weeks Sham, isoproterenol, isoproterenol + ramipril. Isoproterenol induced significant increases of echocardiographically measured left ventricular end-diastolic posterior wall thickness and dimension, whereas ramipril treatment significantly attenuated these changes. Left ventricular end-diastolic pressure was markedly increased in isoproterenol-treated rats and normalized following ramipril. Isoproterenol rats were further characterized by hormonal activations including transient elevations of plasma renin activity, aldosterone and cardiac angiotensin converting enzyme activity. Histomorphological characterization of isoproterenol-treated hearts demonstrated cardiomyocyte necrosis and reparative fibrosis. Ramipril treatment only slightly reduced the amount of necrosis as well as the expression of extracellular matrix proteins.CONCLUSIONS:
In rats, a toxic dosage of isoproterenol caused characteristic myocardial damage that subsequently resulted in mild heart failure. Ramipril administration following isoproterenol was highly effective to attenuate hemodynamic and hormonal alterations as well as the development of left ventricular hypertrophy, but had only little influence on the expression of extracellular matrix proteins. Since angiotensin converting enzyme inhibition had no impact on the initial myocardial injury, the development of heart failure in this model seems to require functional integrity of the renin-angiotensin system.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Sistema Renina-Angiotensina
/
Inhibidores de la Enzima Convertidora de Angiotensina
/
Ramipril
/
Agonistas Adrenérgicos beta
/
Insuficiencia Cardíaca
/
Isoproterenol
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Cardiovasc Res
Año:
1998
Tipo del documento:
Article
País de afiliación:
Alemania