Endurance exercise modifies the circadian clock in zebrafish (Danio rerio) temperature independently.
Acta Physiol (Oxf)
; 205(1): 167-76, 2012 May.
Article
en En
| MEDLINE
| ID: mdl-22044585
AIM: Several rodent and human studies revealed that physical exercise acts as a non-photic zeitgeber for the circadian clock. The intrinsic entraining mechanism is still unknown, although it was assumed that the exercise-mediated increase in core temperature could be the underlying zeitgeber. As the homoeostatic control of mammalian core temperature interferes strongly with the investigation of this hypothesis, the present study used the poikilotherm zebrafish to answer this question. METHODS: Gene transcription levels of the two circadian core clock genes period1 and clock1 were quantified using real-time qPCR of whole animal zebrafish larvae. RESULTS: Long-term endurance exercise of zebrafish larvae aged 9-15 days post-fertilization (dpf) or 21-32 dpf at a constant water temperature of 25 °C caused significantly altered transcription levels of the circadian genes period1 and clock1. Cosinor analysis of diurnal transcription profiles obtained after 3 days of swim training revealed significant differences regarding acrophase, mesor and amplitude of period1, resulting in a phase delay of the gene oscillation. After termination of the exercise bout, at 15 dpf, oscillation amplitudes of both circadian genes were significantly reduced. CONCLUSION: The results showed that physical exercise is able to affect the transcription of circadian genes in developing zebrafish larvae. Considering the poikilothermy of zebrafish, an exercise-mediated change in body core temperature could be excluded as the underlying intrinsic zeitgeber. However, the day-active zebrafish arises as a useful model to address the synchronizing effect of exercise on the circadian clock.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Condicionamiento Físico Animal
/
Resistencia Física
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Temperatura Corporal
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Pez Cebra
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Relojes Circadianos
Límite:
Animals
Idioma:
En
Revista:
Acta Physiol (Oxf)
Asunto de la revista:
FISIOLOGIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Austria
Pais de publicación:
Reino Unido