title: Circadian rhythms in glucose and lipid metabolism in nocturnal and diurnal mammals.
abstract: Most aspects of energy metabolism display clear variations during day and night. This daily rhythmicity of metabolic functions, including hormone release, is governed by a circadian system that consists of the master clock in the suprachiasmatic nuclei of the hypothalamus (SCN) and many secondary clocks in the brain and peripheral organs. The SCN control peripheral timing via the autonomic and neuroendocrine system, as well as via behavioral outputs. The sleep-wake cycle, the feeding/fasting rhythm and most hormonal rhythms, including that of leptin, ghrelin and glucocorticoids, usually show an opposite phase (relative to the light-dark cycle) in diurnal and nocturnal species. By contrast, the SCN clock is most active at the same astronomical times in these two categories of mammals. Moreover, in both species, pineal melatonin is secreted only at night. In this review we describe the current knowledge on the regulation of glucose and lipid metabolism by central and peripheral clock mechanisms. Most experimental knowledge comes from studies in nocturnal laboratory rodents. Nevertheless, we will also mention some relevant findings in diurnal mammals, including humans. It will become clear that as a consequence of the tight connections between the circadian clock system and energy metabolism, circadian clock impairments (e.g., mutations or knock-out of clock genes) and circadian clock misalignments (such as during shift work and chronic jet-lag) have an adverse effect on energy metabolism, that may trigger or enhancing obese and diabetic symptoms.
authors: Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands; Regulation of Circadian Clocks Team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands.
authors: Pawan
authors: P
authors: Kumar Jha
authors: Regulation of Circadian Clocks Team, Institute of Cellular and Integrative Neurosciences, UPR3212, Centre National de la Recherche Scientifique (CNRS), University of Strasbourg, France; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands.
authors: Etienne
authors: E
authors: Challet
authors: Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands; International Associated Laboratory LIA1061 Understanding the Neural Basis of Diurnality, CNRS, France and the Netherlands; Department of Endocrinology and Metabolism, Academic Medical Center (AMC), University of Amsterdam, The Netherlands. Electronic address: a.kalsbeek@amc.uva.nl.
authors: Andries
authors: A
authors: Kalsbeek
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism / Q000502:physiology*; D057906:Circadian Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism; D050356:Lipid Metabolism / Q000502:physiology*; D013493:Suprachiasmatic Nucleus / Q000378:metabolism
chemical_list: D005947:Glucose
keywords: Autonomic nervous system; Circadian rhythm; Glucose metabolism; Hypothalamus; Lipid metabolism; Suprachiasmatic nucleus