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Difference between revisions of "Boveris 1973 Biochem J"

From Bioblast
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{{Labeling
{{Labeling
|organism=Rat
|injuries=Oxidative stress;RONS
|taxonomic group=Birds
|organism=Rat, Birds
|tissues=Heart
|tissues=Heart
|preparations=Isolated mitochondria
|preparations=Isolated mitochondria
|injuries=Oxidative stress;RONS
|topics=Oxygen kinetics, pH, Uncoupler
|topics=Oxygen kinetics, pH, Uncoupler
|couplingstates=LEAK, OXPHOS, ETS
|couplingstates=LEAK, OXPHOS, ETS

Revision as of 08:53, 9 November 2016

Publications in the MiPMap
Boveris A, Chance B (1973) The mitochondrial generation of hydrogen peroxide. General properties and effect of hyperbaric oxygen. Biochem J 134:707-16.

Β» PMID: 4749271 Open Access

Boveris A, Chance B (1973) Biochem J

Abstract: 1. Pigeon heart mitochondria produce H(2)O(2) at a maximal rate of about 20 nmol/min per mg of protein.

2. Succinate-glutamate and malate-glutamate are substrates which are able to support maximal H(2)O(2) production rates. With malate-glutamate, H(2)O(2) formation is sensitive to rotenone. Endogenous substrate, octanoate, stearoyl-CoA and palmitoyl-carnitine are by far less efficient substrates.

3. Antimycin A exerts a very pronounced effect in enhancing H(2)O(2) production in pigeon heart mitochondria; 0.26 nmol of antimycin A/mg of protein and the addition of an uncoupler are required for maximal H(2)O(2) formation.

4. In the presence of endogenous substrate and of antimycin A, ATP decreases and uncoupler restores the rates of H(2)O(2) formation.

5. Reincorporation of ubiquinone-10 and ubiquinone-3 to ubiquinone-depleted pigeon heart mitochondria gives a system in which H(2)O(2) production is linearly related to the incorporated ubiquinone.

6. The generation of H(2)O(2) by pigeon heart mitochondria in the presence of succinate-glutamate and in metabolic State 4 has an optimum pH value of 7.5. In States 1 and 3u, and in the presence of antimycin A and uncoupler, the optimum pH value is shifted towards more alkaline values.

7. With increase of the partial pressure of O(2) to the hyperbaric region the formation of H(2)O(2) is markedly increased in pigeon heart mitochondria and in rat liver mitochondria. With rat liver mitochondria and succinate as substrate in State 4, an increase in the pO(2) up to 1.97 MPa (19.5 atm) increases H(2)O(2) formation 10-15-fold. Similar pO(2) profiles were observed when rat liver mitochondria were supplemented either with antimycin A or with antimycin A and uncoupler. No saturation of the system with O(2) was observed up to 1.97 MPa (19.5 atm). By increasing the pO(2) to 1.97 MPa (19.5atm), H(2)O(2) formation in pigeon heart mitochondria with succinate as substrate increased fourfold in metabolic State 4, with antimycin A added the increase was threefold and with antimycin A and uncoupler it was 2.5-fold. In the last two saturation of the system with oxygen was observed, with an apparent K(m) of about 71 kPa (0.7-0.8 atm) and a V(max) of 12 and 20 nmol of H(2)O(2)/min per mg of protein.

8. It is postulated that in addition to the well-known flavin reaction, formation of H(2)O(2) may be due to interaction with an energy-dependent component of the respiratory chain at the cytochrome b level.


Labels:

Stress:Oxidative stress;RONS  Organism: Rat, Birds  Tissue;cell: Heart  Preparation: Isolated mitochondria 

Regulation: Oxygen kinetics, pH, Uncoupler  Coupling state: LEAK, OXPHOS, ETS"ETS" is not in the list (LEAK, ROUTINE, OXPHOS, ET) of allowed values for the "Coupling states" property.  Pathway: F, N, S, NS 


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