Pham 2014 Am J Physiol: Difference between revisions
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{{Publication | {{Publication | ||
|title=Pham T, Loiselle D, Power A, Hickey AJ (2014) Mitochondrial inefficiencies and anoxic ATP hydrolysis capacities in diabetic rat heart. Am J Physiol 307:C499โ507. | |title=Pham T, Loiselle D, Power A, Hickey AJ (2014) Mitochondrial inefficiencies and anoxic ATP hydrolysis capacities in diabetic rat heart. Am J Physiol 307:C499โ507. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/24920675 PMID: 24920675] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/24920675 PMID: 24920675 Open Access] | ||
|authors=Pham T, Loiselle D, Power A, Hickey AJ | |authors=Pham T, Loiselle D, Power A, Hickey AJ | ||
|year=2014 | |year=2014 | ||
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|abstract=As approximately 80% of diabetics die from heart failure, understanding diabetic cardiomyopathy is crucial. Mitochondria occupy 35-40% of mammalian cardiomyocyte volume, supply 95% of the hearts' ATP, and diabetic heart mitochondria show impaired structure, arrangement and function. We predict that bioenergetic efficiencies are present in diabetic heart mitochondria; therefore we explored mitochondrial proton and electron handling by linking oxygen flux within streptozotocin (STZ)-induced-diabetic Sprague-Dawley rat heart tissues, to steady-state ATP synthesis, Reactive Oxygen Species (ROS) production, and mitochondrial membrane potential (ฮ''ฮจ''). By coupling high-resolution respirometers with purpose-built fluorometers, we followed Magnesium Green (ATP synthesis), Amplex Ultra Red (ROS production), and safranin-O (ฮ''ฮจ''). Relative to control rats, the mass-specific respiration of STZ-diabetic hearts was depressed in oxidative phosphorylating (OXPHOS) states. Steady-state ATP synthesis capacity was almost a third lower in STZ-diabetic heart and relative to O2 flux, this equates to an estimated 12% depression in OXPHOS efficiency. However, with anoxic transition, STZ-diabetic and control heart tissues showed similar ATP hydrolysis capacities through reversal of the F1/F0 ATP-synthase. STZ-diabetic cardiac mitochondria also produced more net ROS relative to oxygen flux (ROS/O) in OXP. While ฮ''ฮจ'' did not differ between groups, the time to develop ฮ''ฮจ'' with the onset of OXPHOS was protracted in STZ-diabetic mitochondria. ROS/O is higher in life-like OXPHOS states and potential delays in the time to develop ฮ''ฮจ'' may delay ATP synthesis with inter-beat fluctuations in ADP concentrations. Whereas diabetic cardiac mitochondria produce less ATP in normoxia, they consume as much ATP in anoxic infarct-like states. | |abstract=As approximately 80% of diabetics die from heart failure, understanding diabetic cardiomyopathy is crucial. Mitochondria occupy 35-40% of mammalian cardiomyocyte volume, supply 95% of the hearts' ATP, and diabetic heart mitochondria show impaired structure, arrangement and function. We predict that bioenergetic efficiencies are present in diabetic heart mitochondria; therefore we explored mitochondrial proton and electron handling by linking oxygen flux within streptozotocin (STZ)-induced-diabetic Sprague-Dawley rat heart tissues, to steady-state ATP synthesis, Reactive Oxygen Species (ROS) production, and mitochondrial membrane potential (ฮ''ฮจ''). By coupling high-resolution respirometers with purpose-built fluorometers, we followed Magnesium Green (ATP synthesis), Amplex Ultra Red (ROS production), and safranin-O (ฮ''ฮจ''). Relative to control rats, the mass-specific respiration of STZ-diabetic hearts was depressed in oxidative phosphorylating (OXPHOS) states. Steady-state ATP synthesis capacity was almost a third lower in STZ-diabetic heart and relative to O2 flux, this equates to an estimated 12% depression in OXPHOS efficiency. However, with anoxic transition, STZ-diabetic and control heart tissues showed similar ATP hydrolysis capacities through reversal of the F1/F0 ATP-synthase. STZ-diabetic cardiac mitochondria also produced more net ROS relative to oxygen flux (ROS/O) in OXP. While ฮ''ฮจ'' did not differ between groups, the time to develop ฮ''ฮจ'' with the onset of OXPHOS was protracted in STZ-diabetic mitochondria. ROS/O is higher in life-like OXPHOS states and potential delays in the time to develop ฮ''ฮจ'' may delay ATP synthesis with inter-beat fluctuations in ADP concentrations. Whereas diabetic cardiac mitochondria produce less ATP in normoxia, they consume as much ATP in anoxic infarct-like states. | ||
|keywords=Diabetic cardiomypathy, Anoxia, Efficiency, Mitochondria, Oxidative phosphorylation, Safranin, Amplex Red, Magnesium Green | |keywords=Diabetic cardiomypathy, Anoxia, Efficiency, Mitochondria, Oxidative phosphorylation, Safranin, Amplex Red, Magnesium Green | ||
|mipnetlab=NZ Auckland Hickey AJ | |mipnetlab=NZ Auckland Hickey AJ, NZ Auckland Pham T | ||
}} | }} | ||
{{Labeling | {{Labeling | ||
|area=Respiration, mt-Medicine | |area=Respiration, mt-Medicine | ||
|diseases=Diabetes, Myopathy | |||
|injuries=Ischemia-reperfusion, Oxidative stress;RONS, Mitochondrial disease | |||
|organism=Rat | |organism=Rat | ||
|tissues=Heart | |tissues=Heart | ||
|preparations=Homogenate | |preparations=Homogenate | ||
|topics=Coupling efficiency;uncoupling, mt-Membrane potential | |topics=Coupling efficiency;uncoupling, mt-Membrane potential | ||
|couplingstates=LEAK, OXPHOS, | |couplingstates=LEAK, OXPHOS, ET | ||
| | |pathways=N, NS, ROX | ||
|instruments=Oxygraph-2k, O2k-Fluorometer | |instruments=Oxygraph-2k, O2k-Fluorometer | ||
|additional= | |additional=Safranin, MgG, AmR, MitoFit 2021 MgG | ||
}} | }} | ||
Demonstration of using Amplex Red, Safranin and Magnesium green methods with the O2k- | Demonstration of using Amplex Red, Safranin and Magnesium green methods with the O2k-Fluorescence Module. | ||
== Correction == | == Correction == | ||
An | An Oroboros Oxygraph-2k was used in this publication, whereas the Anton Paar/Oroboros Oxygraph was the first-generation instrument for high-resolution respirometry, which was replaced by the Oxygraph-2k in 2002. | ||
* ''Further details'': [[Gnaiger 2012 Abstract Bioblast-Gentle Science]] | * ''Further details'': [[Gnaiger 2012 Abstract Bioblast-Gentle Science]] | ||
== Cited by == | |||
{{Template:Cited by Cardoso 2021 MitoFit MgG}} |
Latest revision as of 15:40, 17 January 2023
Pham T, Loiselle D, Power A, Hickey AJ (2014) Mitochondrial inefficiencies and anoxic ATP hydrolysis capacities in diabetic rat heart. Am J Physiol 307:C499โ507. |
Pham T, Loiselle D, Power A, Hickey AJ (2014) Am J Physiol
Abstract: As approximately 80% of diabetics die from heart failure, understanding diabetic cardiomyopathy is crucial. Mitochondria occupy 35-40% of mammalian cardiomyocyte volume, supply 95% of the hearts' ATP, and diabetic heart mitochondria show impaired structure, arrangement and function. We predict that bioenergetic efficiencies are present in diabetic heart mitochondria; therefore we explored mitochondrial proton and electron handling by linking oxygen flux within streptozotocin (STZ)-induced-diabetic Sprague-Dawley rat heart tissues, to steady-state ATP synthesis, Reactive Oxygen Species (ROS) production, and mitochondrial membrane potential (ฮฮจ). By coupling high-resolution respirometers with purpose-built fluorometers, we followed Magnesium Green (ATP synthesis), Amplex Ultra Red (ROS production), and safranin-O (ฮฮจ). Relative to control rats, the mass-specific respiration of STZ-diabetic hearts was depressed in oxidative phosphorylating (OXPHOS) states. Steady-state ATP synthesis capacity was almost a third lower in STZ-diabetic heart and relative to O2 flux, this equates to an estimated 12% depression in OXPHOS efficiency. However, with anoxic transition, STZ-diabetic and control heart tissues showed similar ATP hydrolysis capacities through reversal of the F1/F0 ATP-synthase. STZ-diabetic cardiac mitochondria also produced more net ROS relative to oxygen flux (ROS/O) in OXP. While ฮฮจ did not differ between groups, the time to develop ฮฮจ with the onset of OXPHOS was protracted in STZ-diabetic mitochondria. ROS/O is higher in life-like OXPHOS states and potential delays in the time to develop ฮฮจ may delay ATP synthesis with inter-beat fluctuations in ADP concentrations. Whereas diabetic cardiac mitochondria produce less ATP in normoxia, they consume as much ATP in anoxic infarct-like states. โข Keywords: Diabetic cardiomypathy, Anoxia, Efficiency, Mitochondria, Oxidative phosphorylation, Safranin, Amplex Red, Magnesium Green
โข O2k-Network Lab: NZ Auckland Hickey AJ, NZ Auckland Pham T
Labels: MiParea: Respiration, mt-Medicine
Pathology: Diabetes, Myopathy
Stress:Ischemia-reperfusion, Oxidative stress;RONS, Mitochondrial disease
Organism: Rat
Tissue;cell: Heart
Preparation: Homogenate
Regulation: Coupling efficiency;uncoupling, mt-Membrane potential Coupling state: LEAK, OXPHOS, ET Pathway: N, NS, ROX HRR: Oxygraph-2k, O2k-Fluorometer
Safranin, MgG, AmR, MitoFit 2021 MgG
Demonstration of using Amplex Red, Safranin and Magnesium green methods with the O2k-Fluorescence Module.
Correction
An Oroboros Oxygraph-2k was used in this publication, whereas the Anton Paar/Oroboros Oxygraph was the first-generation instrument for high-resolution respirometry, which was replaced by the Oxygraph-2k in 2002.
- Further details: Gnaiger 2012 Abstract Bioblast-Gentle Science
Cited by
- Cardoso et al (2021) Magnesium Green for fluorometric measurement of ATP production does not interfere with mitochondrial respiration. Bioenerg Commun 2021.1. doi:10.26124/bec:2021-0001