title: Temperature controls oxidative phosphorylation and reactive oxygen species production through uncoupling in rat skeletal muscle mitochondria.
abstract: Mitochondrial respiratory and phosphorylation activities, mitochondrial uncoupling, and hydrogen peroxide formation were studied in isolated rat skeletal muscle mitochondria during experimentally induced hypothermia (25 °C) and hyperthermia (42 °C) compared to the physiological temperature of resting muscle (35 °C). For nonphosphorylating mitochondria, increasing the temperature from 25 to 42 °C led to a decrease in membrane potential, hydrogen peroxide production, and quinone reduction levels. For phosphorylating mitochondria, no temperature-dependent changes in these mitochondrial functions were observed. However, the efficiency of oxidative phosphorylation decreased, whereas the oxidation and phosphorylation rates and oxidative capacities of the mitochondria increased, with increasing assay temperature. An increase in proton leak, including uncoupling protein-mediated proton leak, was observed with increasing assay temperature, which could explain the reduced oxidative phosphorylation efficiency and reactive oxygen species production.
authors.affiliation: Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznan, Poland. Electronic address: wiesiaj@amu.edu.pl.
authors.forename: Wieslawa
authors.initials: W
authors.lastname: Jarmuszkiewicz
authors.affiliation: Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznan, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Woyda-Ploszczyca
authors.affiliation: Department of Bioenergetics, Faculty of Biology, Adam Mickiewicz University, 61-614 Poznan, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Koziel
authors.affiliation: Department of Muscle Physiology, Chair of Physiology and Biochemistry, Faculty of Rehabilitation, University School of Physical Education, Krakow, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Majerczak
authors.affiliation: Department of Muscle Physiology, Chair of Physiology and Biochemistry, Faculty of Rehabilitation, University School of Physical Education, Krakow, Poland.
authors.forename: Jerzy A
authors.initials: JA
authors.lastname: Zoladz
mesh_terms: D000818:Animals; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000378:metabolism; D005334:Fever / Q000503:physiopathology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D007035:Hypothermia / Q000503:physiopathology*; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008931:Mitochondria, Muscle / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D018384:Oxidative Stress; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013696:Temperature
chemical_list: D024101:Mitochondrial Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase
keywords: Free radicals; Mitochondrial function; Oxidative phosphorylation; Skeletal muscle mitochondria; Temperature; Uncoupling protein