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El papel necesario de los miocitos cardíacos en la constricción coronaria alfa1-adrenérgica
C P Tiefenbacher1, D V DeFily, W M Chilian
1Department of Physiology, Medical College of Wisconsin, Milwaukee 53226, USA.
Circulation
|July 17, 1998
Resumen
Los miocitos cardíacos juegan un papel clave en la constricción arterial coronaria alfa1-adrenérgica. Los factores liberados por los miocitos, que potencialmente incluyen la endotelina-1, median esta respuesta, a diferencia de la estimulación directa de los microvasculares.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Biología Vascular Biología Vascular
- La señalización adrenérgica.
Sus antecedentes:
- La activación alfa-adrenérgica típicamente contrae las arteriolas coronarias in vivo.
- Los microvasculares coronarios aislados paradójicamente no se contraen a los estímulos alfa1-adrenérgicos in vitro.
Objetivo del estudio:
- Para investigar el papel de los miocitos cardíacos en la constricción arterial coronaria alfa1-adrenérgica.
- Para identificar posibles factores derivados de los miocitos que median esta vasoconstricción.
Principales métodos:
- Las arteriolas coronarias aisladas fueron expuestas a fenilefrina o supernatante de los miocitos cardíacos tratados con fenilefrina.
- Se utilizaron antagonistas para los receptores de endotelina-A y alfa-adrenérgicos.
- Se administró un antagonista de la adenosina.
- Se midieron los niveles de endotelina-1 en el supernante de los miocitos.
Principales resultados:
- La fenilefrina no restringió directamente las arteriolas aisladas.
- El supernatante de los miocitos tratados indujo la constricción arteriolar.
- La constricción fue bloqueada por antagonistas de endotelina-A y alfa-adrenérgicos.
- El antagonismo de la adenosina aumentó la constricción.
- La fenilefrina aumentó la endotelina-1 de los miocitos a niveles por debajo del umbral.
Conclusiones:
- Los miocitos cardíacos son esenciales para la constricción de los vasos de la resistencia coronaria alfa1-adrenérgica.
- El mecanismo puede implicar la endotelina-1 y otros vasoconstrictores no identificados derivados de los miocitos.
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