title: Depression of mitochondrial respiration during daily torpor of the Djungarian hamster, Phodopus sungorus, is specific for liver and correlates with body temperature.
abstract: Small mammals actively decrease metabolism during daily torpor and hibernation to save energy. Increasing evidence suggests depression of mitochondrial respiration during daily torpor of the Djungarian hamster but tissue-specificity and relation to torpor depth is unknown. We first confirmed a previous study by Brown and colleagues reporting on the depressed substrate oxidation in isolated liver mitochondria of the Djungarian hamster (Phodopus sungorus) during daily torpor. Next, we show that mitochondrial respiration is not depressed in kidneys, skeletal muscle and heart. In liver mitochondria, we found that state 3 and state 4 respirations correlate with body temperature, suggesting inhibition related to torpor depth and to metabolic rate. We conclude that molecular events leading to depression of mitochondrial respiration during daily torpor are specific to liver and linked to a decrease in body temperature. Different tissue-specificity of mitochondrial depression may assist to compare and identify the molecular nature of mitochondrial alterations during torpor.
authors: Institute for Diabetes and Obesity, Helmholtz Centre Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors: Maria
authors: M
authors: Kutschke
authors: Kirsten
authors: K
authors: Grimpo
authors: Anja
authors: A
authors: Kastl
authors: Sandra
authors: S
authors: Schneider
authors: Gerhard
authors: G
authors: Heldmaier
authors: Cornelia
authors: C
authors: Exner
authors: Martin
authors: M
authors: Jastroch
mesh_terms: D000818:Animals; D001481:Basal Metabolism / Q000502:physiology; D001831:Body Temperature / Q000502:physiology*; D019069:Cell Respiration / Q000502:physiology*; D006224:Cricetinae; D006605:Hibernation / Q000502:physiology*; D008099:Liver / Q000502:physiology*; D008930:Mitochondria, Liver / Q000502:physiology*; D017111:Phodopus / Q000502:physiology*