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Efecto del envejecimiento en la Ca2+ intracelular, pHi y contractilidad durante la isquemia y la reperfusión
1Department of Surgery, Harvard Medical School, Boston, MA.
Circulation
|November 1, 1992
Resumen
El envejecimiento aumenta la acumulación de calcio citosólico (Ca2+) durante la isquemia, lo que lleva a una función cardíaca reducida después de la reperfusión. Los corazones envejecidos muestran una recuperación deteriorada en comparación con los corazones maduros, con niveles más altos de Ca2 + correlacionados con el deterioro funcional.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Investigación sobre el envejecimiento Investigación sobre el envejecimiento.
- Las lesiones por isquemia-reperfusión.
Sus antecedentes:
- El envejecimiento afecta la susceptibilidad del miocardio a lesiones isquémicas y de reperfusión.
- Factores clave como el calcio citosólico (Ca2+) y el pH intracelular (pHi) están implicados.
Objetivo del estudio:
- Investigar los efectos del envejecimiento en la lesión isquémica y de reperfusión del miocardio.
- Para evaluar los cambios relacionados con la edad en el Ca2+ citosólico, pHi y el rendimiento mecánico.
Principales métodos:
- Se utilizaron corazones de conejo perfundidos aislados de grupos maduros y ancianos.
- Los corazones se sometieron a isquemia y reperfusión normotérmica.
- El Ca2+ y el pHi citosólicos se midieron utilizando indicadores fluorescentes (fura-2, BCECF).
Principales resultados:
- Los corazones envejecidos mostraron un aumento significativamente mayor en el Ca2+ citosólico durante la isquemia en comparación con los corazones maduros.
- Ambos grupos experimentaron disminuciones similares en el pHi durante la isquemia.
- La recuperación funcional de la presión máxima del ventrículo izquierdo fue significativamente menor en los corazones envejecidos (55%) frente a los corazones maduros (84%).
Conclusiones:
- Los corazones envejecidos exhiben una mayor acumulación de Ca2+ durante la isquemia, lo que se correlaciona con una recuperación funcional reducida.
- Este aumento elevado de Ca2+ en los corazones envejecidos no se atribuye a diferencias en la capacidad de amortiguación de la acidosis.
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