Difference between revisions of "Brown 2012 Am J Physiol Regul Integr Comp Physiol"
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{{Publication | {{Publication | ||
|title=Brown JC, Chung DJ, Belgrave KR, Staples JF (2014) Mitochondrial metabolic suppression and reactive oxygen species production in liver and skeletal muscle of hibernating thirteen-lined ground squirrels | |title=Brown JC, Chung DJ, Belgrave KR, Staples JF (2014) Mitochondrial metabolic suppression and reactive oxygen species production in liver and skeletal muscle of hibernating thirteen-lined ground squirrels. Am J Physiol Regul Integr Comp Physiol 302:R15-28. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/21993528 PMID: 21993528] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/21993528 PMID: 21993528] | ||
|authors=Brown JC, Chung DJ, Belgrave KR, Staples JF | |authors=Brown JC, Chung DJ, Belgrave KR, Staples JF | ||
|year=2014 | |year=2014 | ||
|journal=Am J Physiol Regul Integr Comp Physiol | |journal=Am J Physiol Regul Integr Comp Physiol | ||
|abstract=During hibernation, animals cycle between periods of torpor, during which body temperature (T(b)) and metabolic rate (MR) are suppressed for days, and interbout euthermia (IBE), during which T(b) and MR return to resting levels for several hours. In this study, we measured respiration rates, membrane potentials, and reactive oxygen species (ROS) production of liver and skeletal muscle mitochondria isolated from ground squirrels (Ictidomys tridecemlineatus) during torpor and IBE to determine how mitochondrial metabolism is suppressed during torpor and how this suppression affects oxidative stress. In liver and skeletal muscle, state 3 respiration measured at | |abstract=During hibernation, animals cycle between periods of torpor, during which body temperature (T(b)) and metabolic rate (MR) are suppressed for days, and interbout euthermia (IBE), during which T(b) and MR return to resting levels for several hours. In this study, we measured respiration rates, membrane potentials, and reactive oxygen species (ROS) production of liver and skeletal muscle mitochondria isolated from ground squirrels (''Ictidomys tridecemlineatus'') during torpor and IBE to determine how mitochondrial metabolism is suppressed during torpor and how this suppression affects oxidative stress. In liver and skeletal muscle, state 3 respiration measured at 37 °C with succinate was 70% and 30% lower, respectively, during torpor. In liver, this suppression was achieved largely via inhibition of substrate oxidation, likely at succinate dehydrogenase. In both tissues, respiration by torpid mitochondria further declined up to 88% when mitochondria were cooled to 10 °C, close to torpid T(b). In liver, this passive thermal effect on respiration rate reflected reduced activity of all components of oxidative phosphorylation (substrate oxidation, phosphorylation, and proton leak). With glutamate & malate & succinate, mitochondrial free radical leak (FRL; proportion of electrons leading to ROS production) was higher in torpor than IBE, but only in liver. With succinate, higher FRL likely resulted from increased reduction state of Complex III during torpor. With glutamate & malate, higher FRL resulted from active suppression of Complex I ROS production during IBE, which may limit ROS production during arousal. In both tissues, ROS production and FRL declined with temperature, suggesting ROS production is also reduced during torpor by passive thermal | ||
|mipnetlab=CA London Staples JF, CA Vancouver Richards JG | |mipnetlab=CA London Staples JF, CA Vancouver Richards JG | ||
}} | }} | ||
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|preparations=Isolated Mitochondria | |preparations=Isolated Mitochondria | ||
|injuries=RONS; Oxidative Stress, Temperature | |injuries=RONS; Oxidative Stress, Temperature | ||
|topics=Temperature | |||
|couplingstates=LEAK, OXPHOS, ETS | |couplingstates=LEAK, OXPHOS, ETS | ||
|substratestates=CI, CII, CIII | |substratestates=CI, CII, CIII | ||
Revision as of 00:59, 6 January 2015
| Brown JC, Chung DJ, Belgrave KR, Staples JF (2014) Mitochondrial metabolic suppression and reactive oxygen species production in liver and skeletal muscle of hibernating thirteen-lined ground squirrels. Am J Physiol Regul Integr Comp Physiol 302:R15-28. |
Brown JC, Chung DJ, Belgrave KR, Staples JF (2014) Am J Physiol Regul Integr Comp Physiol
Abstract: During hibernation, animals cycle between periods of torpor, during which body temperature (T(b)) and metabolic rate (MR) are suppressed for days, and interbout euthermia (IBE), during which T(b) and MR return to resting levels for several hours. In this study, we measured respiration rates, membrane potentials, and reactive oxygen species (ROS) production of liver and skeletal muscle mitochondria isolated from ground squirrels (Ictidomys tridecemlineatus) during torpor and IBE to determine how mitochondrial metabolism is suppressed during torpor and how this suppression affects oxidative stress. In liver and skeletal muscle, state 3 respiration measured at 37 °C with succinate was 70% and 30% lower, respectively, during torpor. In liver, this suppression was achieved largely via inhibition of substrate oxidation, likely at succinate dehydrogenase. In both tissues, respiration by torpid mitochondria further declined up to 88% when mitochondria were cooled to 10 °C, close to torpid T(b). In liver, this passive thermal effect on respiration rate reflected reduced activity of all components of oxidative phosphorylation (substrate oxidation, phosphorylation, and proton leak). With glutamate & malate & succinate, mitochondrial free radical leak (FRL; proportion of electrons leading to ROS production) was higher in torpor than IBE, but only in liver. With succinate, higher FRL likely resulted from increased reduction state of Complex III during torpor. With glutamate & malate, higher FRL resulted from active suppression of Complex I ROS production during IBE, which may limit ROS production during arousal. In both tissues, ROS production and FRL declined with temperature, suggesting ROS production is also reduced during torpor by passive thermal
• O2k-Network Lab: CA London Staples JF, CA Vancouver Richards JG
Labels: MiParea: Respiration
Stress:RONS; Oxidative Stress"RONS; Oxidative Stress" is not in the list (Cell death, Cryopreservation, Ischemia-reperfusion, Permeability transition, Oxidative stress;RONS, Temperature, Hypoxia, Mitochondrial disease) of allowed values for the "Stress" property., Temperature Organism: Other mammals Tissue;cell: Heart, Skeletal muscle Preparation: Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.
Regulation: Temperature Coupling state: LEAK, OXPHOS, ETS"ETS" is not in the list (LEAK, ROUTINE, OXPHOS, ET) of allowed values for the "Coupling states" property.
HRR: Oxygraph-2k
Labels
