Rapamycin attenuates load-induced cardiac hypertrophy in mice.
Circulation
; 107(12): 1664-70, 2003 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-12668503
ABSTRACT
BACKGROUND:
Cardiac hypertrophy, or an increase in heart size, is an important risk factor for cardiac morbidity and mortality. The mammalian target of rapamycin (mTOR) is a component of the insulin-phosphoinositide 3-kinase pathway, which is known to play a critical role in the determination of cell, organ, and body size. METHODS ANDRESULTS:
To examine the role of mTOR in load-induced cardiac hypertrophy, we administered rapamycin, a specific inhibitor of mTOR, to mice with ascending aortic constriction. Activity of p70 ribosomal S6 kinase 1 (S6K1), an effector of mTOR, was increased by 3.8-fold in the aortic-constricted heart. Pretreatment of mice with 2 mg. kg-1. d-1 of rapamycin completely suppressed S6K1 activation and S6 phosphorylation in response to pressure overload. The heart weight/tibial length ratio of vehicle-treated aortic-banded mice was increased by 34.4+/-3.6% compared with vehicle-treated sham-operated mice. Rapamycin suppressed the load-induced increase in heart weight by 67%. Attenuation of cardiac hypertrophy by rapamycin was associated with attenuation of the increase in myocyte cell size induced by aortic constriction. Rapamycin did not cause loss of body weight, lethality, or left ventricular dysfunction.CONCLUSIONS:
mTOR or its target(s) seems to play an important role in load-induced cardiac hypertrophy. Because systemic administration of rapamycin has been used successfully for the treatment of transplant rejection in clinical practice, it may be a useful therapeutic modality to suppress cardiac hypertrophy in patients.
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Bases de dados:
MEDLINE
Assunto principal:
Cardiomegalia
/
Sirolimo
/
Inibidores de Proteínas Quinases
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Circulation
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos