Mitochondrial sites of hydrogen peroxide production in reperfused rat kidney cortex.

Abstract

Electron transport and production of O2-/H2O2 by the NADH dehydrogenase flavin-semiquinone (FMNH.) and ubisemiquinone (UQH.) were studied in a model of in vivo ischemia-reperfusion in rat kidney. H2O2 production rates were assessed in isolated mitochondria using either succinate, with and without antimycin, or malate-glutamate, with and without rotenone. Respiratory activities of isolated mitochondria and activity of NADH- and succinate-cytochrome c reductase and of NADH- and succinate-dehydrogenase in submitochondrial particles were measured to evaluate the electron flux throughout respiratory carriers. The mitochondrial H2O2 production rate was approximately 1.5- and 4-times increased in ischemic and ischemic-reperfused kidneys, respectively. Ischemia caused a marked decrease in the electron transport throughout the NADH-UQ segment with no significant changes either in the NADH dehydrogenase activity or in the electron flux trough the succinate-cytochrome oxidase segment. Reperfusion did not further affect the NADH-ubiquinone segment but markedly inhibited the succinate-supported oxygen consumption, succinate-cytochrome c reductase and succinate dehydrogenase activity. Our results show a redistribution of the electron flux with an increased rate of superoxide anion/hydrogen peroxide production at NADH dehydrogenase in mitochondria subjected to ischemia only. After 10 min reperfusion an impairment of the electron flow at succinate-cytochrome c segment is established and hydrogen peroxide production by UQH. increases up to maximal values becoming the major source of superoxide anion/hydrogen peroxide.

• Authors: B González-Flecha, A Boveris
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1243 Issue 3 Pg. 361-6 (Apr 13 1995) ISSN: 0006-3002 [Print] Netherlands
• PMID: 7727510 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Superoxides
• Hydrogen Peroxide
• Succinate Cytochrome c Oxidoreductase
• Succinate Dehydrogenase
• NADH Dehydrogenase

Topics

• Animals
• Electron Transport
• Hydrogen Peroxide (metabolism)
• Ischemia (metabolism)
• Kidney Cortex (blood supply, ultrastructure)
• Kinetics
• Male
• Mitochondria (metabolism)
• NADH Dehydrogenase (metabolism)
• Oxygen Consumption
• Rats
• Rats, Wistar
• Reperfusion
• Submitochondrial Particles (metabolism)
• Succinate Cytochrome c Oxidoreductase (metabolism)
• Succinate Dehydrogenase (metabolism)
• Superoxides (metabolism)