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Relaciones dosis-respuesta para el restablecimiento del reloj circadiano humano por luz
D B Boivin1, J F Duffy, R E Kronauer
1Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|February 8, 1996
Resumen
Los marcapasos circadianos humanos son más sensibles a la luz de lo que se pensaba anteriormente. Incluso los bajos niveles de luz en interiores (alrededor de 180 lux) pueden cambiar significativamente el cuerpo.
Área de la Ciencia:
- Cronobiología cronobiología.
- Fisiología Humana Fisiología Humana.
- Ciencia del sueño Ciencia del sueño Ciencia del sueño
Sus antecedentes:
- La luz es un sincronizador conocido de marcapasos circadianos endógenos en todas las especies.
- La luz brillante (7.000 13.000 lux) sincroniza efectivamente los ritmos circadianos humanos.
- Una creencia común es que los marcapasos circadianos humanos son insensibles a la luz interior típica (50300 lux).
Objetivo del estudio:
- Para investigar la hipótesis de que el marcapasos circadiano humano es sensible a intensidades de luz más bajas.
- Para determinar si los niveles de iluminación en interiores pueden cambiar de fase significativamente el marcapasos circadiano humano.
- Para comparar los mecanismos de arrastre circadiano humano con los de otros mamíferos.
Principales métodos:
- Realizó experimentos exponiendo a los participantes humanos a intensidades de luz controladas.
- Se midieron los efectos de cambio de fase de la luz de baja intensidad (aproximadamente 180 lux) en el marcapasos circadiano humano.
- Analizó la relación dependiente de la intensidad entre la exposición a la luz y el restablecimiento del ritmo circadiano.
Principales resultados:
- La exposición a la luz a una intensidad relativamente baja (aproximadamente 180 lux) cambió significativamente la fase del marcapasos circadiano humano.
- Se demostró que los seres humanos son considerablemente más sensibles a los efectos de la luz que influyen en el ritmo circadiano de lo que se sospechaba anteriormente.
- El efecto de restablecimiento de la luz en el marcapasos circadiano humano sigue una función compresiva no lineal.
Conclusiones:
- El marcapasos circadiano humano es sensible a los niveles normales de iluminación en interiores.
- Los seres humanos no son cualitativamente diferentes de otros mamíferos con respecto a sus mecanismos de arrastre circadiano.
- Las intensidades de luz más bajas pueden ejercer un efecto robusto en la sincronización del ritmo circadiano.
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