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El bario reduce el flujo sanguíneo en reposo e inhibe la vasodilatación inducida por el potasio en el antebrazo
Matthew Dawes1, Christine Sieniawska, Trevor Delves
1Department of Clinical Pharmacology and Centre for Cardiovascular Biology and Medicine, King's College, London, UK.
Circulation
|March 20, 2002
Resumen
Los canales de potasio de rectificación interna (KIR) y la Na+/K+ ATPasa juegan un papel clave en la regulación del tono de los vasos sanguíneos y la vasodilatación inducida por el potasio en los vasos del antebrazo humano.
Área de la Ciencia:
- Fisiología Fisiología Fisiología.
- Investigación Cardiovascular Investigación Cardiovascular Investigación Cardiovascular Investigación Cardiovascular Investigación Cardiovascular
- Función del canal iónico Función del canal iónico
Sus antecedentes:
- El potasio extracelular (K+) hiperpolariza y relaja el músculo liso vascular in vitro.
- Los canales de potasio de rectificación interna (KIR) y la Na+/K+ ATPasa median estos efectos vasculares inducidos por K+.
- El papel de KIR en los vasos de resistencia del antebrazo humano sigue sin caracterizarse.
Objetivo del estudio:
- Para investigar el papel de KIR y Na+/K+ ATPasa en el control del tono vascular del antebrazo humano.
- Para determinar la participación de estos canales en la vasodilatación inducida por K+.
Principales métodos:
- Los sujetos masculinos sanos se sometieron a mediciones del flujo sanguíneo en el antebrazo a través de la pletismografía.
- Los fármacos y electrolitos, incluidos el cloruro de bario (BaCl2), ouabaina y cloruro de potasio (KCl), se infundieron intraarterialmente.
- Se evaluaron las respuestas con y sin inhibidores de KIR y Na+/K+ ATPasa.
Principales resultados:
- La infusión de BaCl2 aumentó la resistencia vascular del antebrazo e inhibió la vasodilatación inducida por K+.
- Ouabain también redujo el flujo sanguíneo y potenció el efecto inhibidor de BaCl2 en la vasodilatación inducida por K+.
- La vasodilatación inducida por K+ fue atenuada significativamente por BaCl2 y casi abolida por BaCl2 más ouabain.
Conclusiones:
- KIR y Na+/K+ ATPasa están implicados en el mantenimiento del tono vascular basal en los vasos de resistencia del antebrazo humano.
- Estos mecanismos de transporte de iones son cruciales para la vasodilatación inducida por K+ en este lecho vascular.
- La orientación de KIR y Na+/K+ ATPasa puede ofrecer un potencial terapéutico para las afecciones cardiovasculares.
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