title: [Circadian clocks and energy metabolism in rodents].
abstract: Circadian rhythmicity is an important component of physiological processes which provides them with a 24-hour temporal organization and adjustment to cyclical changes in the environment. Circadian rhythms are controlled by a network of endogenous clocks, comprising the main clock in the suprachiasmatic nuclei of the hypothalamus and many secondary clocks in the brain and peripheral tissues. All aspects of energy metabolism, from food intake to intracellular signaling pathways, are strongly influenced by circadian rhythmicity. In turn, meal timing is an efficient synchronizer (time-giver) to set the phase of the peripheral clocks, while the suprachiasmatic clock is synchronized by ambient light. In certain nutritional conditions (i.e., low- or high-calory diets), metabolic factors remaining to be identified modulate the functioning of the suprachiasmatic clock. Animal models of obesity and diabetes show circadian alterations. Conversely, when circadian rhythmicity is disturbed, either due to genetically defective circadian clocks, or to circadian desynchronization (chronic light exposure or repeated meals at odd times of the cycle), lipid and glucose metabolism is deregulated. The metabolic impact of circadian desynchronization justifies the development of preventive or therapeutic strategies that could rely, among others, on dietary interventions combining timed meals and specific composition.
authors.forename: Etienne
authors.initials: E
authors.lastname: Challet
mesh_terms: D000818:Animals; D056926:CLOCK Proteins / Q000502:physiology; D021081:Chronobiology Disorders / Q000378:metabolism / Q000503:physiopathology; D057906:Circadian Clocks / Q000502:physiology* / Q000528:radiation effects; D002940:Circadian Rhythm / Q000502:physiology* / Q000528:radiation effects; D004734:Energy Metabolism / Q000502:physiology* / Q000528:radiation effects; D005247:Feeding Behavior / Q000502:physiology; D005947:Glucose / Q000378:metabolism; D006943:Hyperglycemia / Q000503:physiopathology; D008027:Light; D050356:Lipid Metabolism / Q000502:physiology / Q000528:radiation effects; D008954:Models, Biological; D009765:Obesity / Q000503:physiopathology; D017440:Photoperiod; D011924:Rats, Zucker; D012306:Risk; D012377:Rodentia / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D013493:Suprachiasmatic Nucleus / Q000502:physiology
chemical_list: D056926:CLOCK Proteins; D005947:Glucose