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Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles
Published on: November 1, 2012
El resorte del puente cruzado: ¿pueden los músculos fríos almacenar energía elástica?
N T George1, T C Irving, C D Williams
1Department of Biology, University of Washington, Seattle, WA 98195-1800, USA. ntgeorge@uw.edu
Science (New York, N.Y.)
|April 27, 2013
Resumen
Los músculos de vuelo de los insectos almacenan energía elástica utilizando motores moleculares llamados puentes cruzados, no solo miofilmentos extensibles. Los gradientes de temperatura dentro de los músculos ayudan a que estos puentes cruzados actúen como resortes, ayudando a la locomoción.
Área de la Ciencia:
- Fisiología muscular La fisiología muscular.
- La biofísica es la biofísica.
- Mecánica de vuelo de los insectos.
Sus antecedentes:
- Los músculos funcionan más allá de la generación de fuerza, almacenando potencialmente energía como resortes para impulsar la locomoción.
- Los miofilantes extensibles se consideran tradicionalmente los sitios primarios para el almacenamiento de energía elástica en los músculos.
Objetivo del estudio:
- Investigar el papel de los gradientes de temperatura intramuscular en el almacenamiento elástico de energía.
- Para determinar si los motores moleculares (puentes cruzados) pueden almacenar energía de deformación elástica dentro de los músculos.
Principales métodos:
- Utilizamos difracción de rayos X de ángulo pequeño con resolución temporal (SAX) en los músculos de vuelo de Manduca sexta.
- Realizó mediciones in situ del intercambio de energía mecánica durante la actividad muscular.
- Se capturaron datos de difracción de rayos X de alta velocidad para observar la dinámica del puente cruzado.
Principales resultados:
- Se demostró que los gradientes de temperatura intramusculares influyen en las tasas de ciclismo de puente cruzado.
- Se observó ciclismo de puente cruzado inferior en regiones musculares más frías.
- Proporcionó evidencia de que estos puentes cruzados pueden almacenar y devolver energía elástica durante los cambios de longitud muscular.
Conclusiones:
- Los puentes cruzados en los músculos de vuelo de los insectos pueden funcionar como resortes moleculares para el almacenamiento de energía elástica.
- Este mecanismo complementa o reemplaza el almacenamiento de energía por medio de myofilamentos extensibles.
- Sugiere un papel novedoso para los puentes cruzados más allá de la contracción muscular, crucial para una locomoción eficiente.
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