Komlodi 2016 Abstract IOC116: Difference between revisions
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{{Abstract | {{Abstract | ||
|title=The effect of Ξ''Ξ¨''<sub>mt</sub> and ΞpH on mitochondrial reactive oxygen species production - A comparative study using mitochondria isolated from different mammalian tissues. | |title=Komlodi T, Geibl F, Sassani M, Adam-Vizi V, Tretter L (2016) The effect of Ξ''Ξ¨''<sub>mt</sub> and ΞpH on mitochondrial reactive oxygen species production - A comparative study using mitochondria isolated from different mammalian tissues. Mitochondr Physiol Network 21.11 | ||
|info=Mitochondr Physiol Network 21.11 | |info=Mitochondr Physiol Network 21.11 | ||
|authors=Komlodi T, Geibl F, Sassani M, Adam-Vizi V, Tretter L | |authors=Komlodi T, Geibl F, Sassani M, Adam-Vizi V, Tretter L | ||
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{{Labeling | {{Labeling | ||
|area=Respiration, mt-Membrane, mt-Medicine, Pharmacology;toxicology | |area=Respiration, mt-Membrane, mt-Medicine, Pharmacology;toxicology | ||
|injuries=Oxidative stress;RONS | |||
|organism=Guinea pig | |organism=Guinea pig | ||
|tissues=Heart, Skeletal muscle, Nervous system | |tissues=Heart, Skeletal muscle, Nervous system | ||
|preparations=Isolated mitochondria | |preparations=Isolated mitochondria | ||
|instruments=Oxygraph-2k, O2k-Fluorometer | |instruments=Oxygraph-2k, O2k-Fluorometer | ||
|additional=Amplex Red, Safranine-O | |additional=Amplex Red, Safranine-O |
Revision as of 19:00, 20 November 2016
Komlodi T, Geibl F, Sassani M, Adam-Vizi V, Tretter L (2016) The effect of ΞΞ¨mt and ΞpH on mitochondrial reactive oxygen species production - A comparative study using mitochondria isolated from different mammalian tissues. Mitochondr Physiol Network 21.11 |
Link: Mitochondr Physiol Network 21.11
Komlodi T, Geibl F, Sassani M, Adam-Vizi V, Tretter L (2016)
Event: IOC116
The generation of mitochondrial reactive oxygen species (ROS) has a great role in many neurodegenerative diseases (Alzheimerβs and Parkinsonβs disease) and in myocardial ischemia-reperfusion injury. It is widely accepted that a high percentage of ROS production is dependent on the proton motive force (PMF), which is the electrochemical potential difference of protons across the inner mitochondrial membrane, composed of ΞΞ¨mt and ΞpH. According to the literature, depolarization of the mitochondrial membrane and decline of the ΞpH result in decreased ROS generation. In this study we have compared the dependence of succinate supported ROS production on the ΞΞ¨mt and ΞpH in mitochondria isolated from guinea-pig brain, heart and skeletal muscle. Consequently, we examined which one of the two components of PMF played a greater role in mitochondrial ROS generation.
Experiments were carried out on isolated brain, heart and skeletal muscle mitochondria prepared from guinea-pig. Mitochondria were energized with succinate, which supports the reverse electron flow, the major mitochondrial ROS source in vitro. Amplex Ultra Red fluorescent dye was used to measure mitochondrial ROS production. The changes of ΞΞ¨mt were detected with safranine-O fluorescence, intramitochondrial pH was determined with BCECF fluorescence. Analysis of mitochondrial respiratory control was carried out with high-resolution respirometry. In order to separate the two components of the PMF (ΞΞ¨mt and ΞpH) ionophores (valinomycin and nigericin) were used.
The effects of ionophores showed the same tendency in brain and heart mitochondria. In the presence of valinomycin, a K+ ionophore, at low [K+], we measured a drop in ΞΞ¨mt, a consequent elevation of matrix pH and ΞpH with a corresponding decline of H2O2 production. The addition of nigericin, a K+/H+ exchanger, decreased mitochondrial ΞpH, this was followed by a compensatory increase of ΞΞ¨mt resulted in an elevation of ROS generation.
Based on our measurements we can conclude that ΞΞ¨mt has a greater role in modulation of mitochondrial ROS generation compared to ΞpH in brain, heart and skeletal muscle mitochondria; thus we have not seen tissue specificity regarding the effect of ionophores on ROS production.
β’ O2k-Network Lab: HU Budapest Tretter L
Labels: MiParea: Respiration, mt-Membrane, mt-Medicine, Pharmacology;toxicology
Stress:Oxidative stress;RONS Organism: Guinea pig Tissue;cell: Heart, Skeletal muscle, Nervous system Preparation: Isolated mitochondria
HRR: Oxygraph-2k, O2k-Fluorometer
Amplex Red, Safranine-O
Affiliations and support
Dept Med Biochem, Semmelweis Univ Lab for Neurobiochem, Hungarian Acad Sc, Budapest, Hungary. - komlodi.timea@med.semmelweis-univ.hu
Supported by: OTKA (NK 81983), TAMOP (4.2.2./B-09/1), MTA (MTA TKI 2013), and Hungarian Brain Research Program (Grant No. KTIA_13_NAP-A-III/6)