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| Salin, Karine; Villasevil, Eugenia M.; Anderson, Graeme J.; Selman, Colin; Chinopoulos, Christos; Metcalfe, Neil B.. |
| Mitochondrial efficiency is typically taken to represent an animal’s capacity to convert its resources into ATP. However, the term mitochondrial efficiency, as currently used in the literature, can be calculated as either the respiratory control ratio, RCR (ratio of mitochondrial respiration supporting ATP synthesis to that required to offset the proton leak) or as the amount of ATP generated per unit of oxygen consumed, ATP/O ratio. The question of how flexibility in mitochondrial energy properties (i.e. in rates of respiration to support ATP synthesis and offset proton leak, and in the rate of ATP synthesis) affects these indices of mitochondrial efficiency has tended to be overlooked. Furthermore, little is known of whether the RCR and ATP/O ratio vary... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56014/57529.pdf |
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| Salin, Karine; Villasevil, Eugenia M.; Auer, Sonya K.; Anderson, Graeme J.; Selman, Colin; Metcalfe, Neil B.; Chinopoulos, Christos. |
| The use of tissue homogenate has greatly aided the study of the functioning of mitochondria. However, the amount of ATP produced per oxygen molecule consumed, that is, the effective P/O ratio, has never been measured directly in tissue homogenate. Here we combine and refine existing methods previously used in permeabilized cells and isolated mitochondria to simultaneously measure mitochondrial ATP production (JATP) and oxygen consumption (JO(2)) in tissue homogenate. A major improvement over existing methods is in the control of ATPases that otherwise interfere with the ATP assay: our modified technique facilitates simultaneous measurement of the rates of uncorrected ATP synthesis and of ATP hydrolysis, thus minimizing the amount of tissue and time needed.... |
| Tipo: Text |
Palavras-chave: ATPase; Fluorescence; Magnesium green; Oxidative phosphorylation; Oxygraph. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00414/52500/53300.pdf |
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| Salin, Karine; Auer, Sonya K.; Rey, Benjamin; Selman, Colin; Metcalfe, Neil B.. |
| It is often assumed that an animal's metabolic rate can be estimated through measuring the whole-organism oxygen consumption rate. However, oxygen consumption alone is unlikely to be a sufficient marker of energy metabolism in many situations. This is due to the inherent variability in the link between oxidation and phosphorylation; that is, the amount of adenosine triphosphate (ATP) generated per molecule of oxygen consumed by mitochondria (P/O ratio). In this article, we describe how the P/O ratio can vary within and among individuals, and in response to a number of environmental parameters, including diet and temperature. As the P/O ratio affects the efficiency of cellular energy production, its variability may have significant consequences for animal... |
| Tipo: Text |
Palavras-chave: Mitochondrial coupling efficiency; Life history; Oxidative stress; Reactive oxygen species; Trade-off; Uncoupling. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00414/52509/53322.pdf |
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| Salin, Karine; Villasevil, Eugenia M.; Anderson, Graeme J.; Auer, Sonya K.; Selman, Colin; Hartley, Richard C.; Mullen, William; Chinopoulos, Christos; Metcalfe, Neil B.. |
| Many animals experience periods of food shortage in their natural environment. It has been hypothesised that the metabolic responses of animals to naturally‐occurring periods of food deprivation may have long‐term negative impacts on their subsequent life‐history. In particular, reductions in energy requirements in response to fasting may help preserve limited resources but potentially come at a cost of increased oxidative stress. However, little is known about this trade‐off since studies of energy metabolism are generally conducted separately from those of oxidative stress. Using a novel approach that combines measurements of mitochondrial function with in vivo levels of hydrogen peroxide (H2O2) in brown trout (Salmo trutta), we show here that fasting... |
| Tipo: Text |
Palavras-chave: High-resolution respirometry; In vivo; Liver atrophy; MitoB probe; Mitochondrial respiratory state. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56022/57540.pdf |
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| Salin, Karine; Auer, Sonya K.; Rudolf, Agata M.; Anderson, Graeme J.; Selman, Colin; Metcalfe, Neil B.. |
| Standard metabolic rate (SMR) and maximum metabolic rate (MMR) typically vary two-or threefold among conspecifics, with both traits assumed to significantly impact fitness. However, the underlying mechanisms that determine such intraspecific variation are not well understood. We examined the influence of mitochondrial properties on intraspecific variation in SMR and MMR and hypothesized that if SMR supports the cost of maintaining the metabolic machinery required for MMR, then the mitochondrial properties underlying these traits should be shared. Mitochondrial respiratory capacity (leak and phosphorylating respiration) and mitochondrial content (cytochrome c oxidase activity) were determined in the liver and white muscle of brown trout Salmo trutta of... |
| Tipo: Text |
Palavras-chave: Brown trout; Fish; Liver; Oxygen consumption; White muscle. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00413/52497/53321.pdf |
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