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Falta de papel directo del calcio en la disfunción diastólica isquémica en corazones aislados
F R Eberli1, H Strömer, M A Ferrell
1Cardiac Muscle Research Laboratory, Boston University School of Medicine, Boston, MA, USA.
Circulation
|November 22, 2000
Resumen
La disfunción diastólica isquémica no es causada directamente por cambios en los niveles intracelulares de calcio. Los experimentos que alteraron la disponibilidad de calcio durante la isquemia no afectaron la presión diastólica ventricular izquierda.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Investigación de la isquemia miocárdica Investigación de la isquemia miocárdica.
- La señalización del calcio en el músculo cardíaco.
Sus antecedentes:
- La isquemia conduce a un aumento del calcio intracelular y la disfunción diastólica.
- El papel directo de los niveles de calcio de los miocitos en la disfunción diastólica isquémica requiere una aclaración.
Objetivo del estudio:
- Investigar si los niveles de calcio intracelular determinan directamente la disfunción diastólica durante la isquemia.
Principales métodos:
- Corazones aislados de ratas y conejos fueron sometidos a isquemia de bajo flujo.
- Se manipularon los niveles de calcio extracelular y se midió el calcio intracelular utilizando aequorin.
- Las presiones del ventrículo izquierdo fueron monitoreadas durante los experimentos.
Principales resultados:
- La isquemia de bajo flujo aumentó el calcio intracelular diastólico en un 270% y ralentizó la disminución transitoria del calcio.
- Los aumentos experimentales en el calcio extracelular duplicaron el calcio intracelular, pero no empeoraron la presión diastólica isquémica.
- La alteración de la disponibilidad de calcio durante la isquemia no afectó la presión diastólica ventricular izquierda.
Conclusiones:
- La disfunción diastólica isquémica no está mediada directamente por la tensión activada por el calcio.
- Los niveles de calcio en los miocitos pueden no ser el principal conductor de la disfunción diastólica durante la isquemia.
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