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Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases
08:57

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases

Published on: February 24, 2018

Reactive oxygen species are involved in the stimulation of the mitochondrial permeability transition by

Sarune Morkunaite-Haimi1, Alexey G Kruglov, Vera V Teplova

  • 1Department of Applied Chemistry and Microbiology, Viikki Biocentre I, University of Helsinki, P.O. Box 56, FIN-00014 Helsinki, Finland.

Biochemical Pharmacology
|December 11, 2002
PubMed

Insights

Dihydrolipoic acid (DHLA) stimulates mitochondrial permeability transition (MPT) by increasing superoxide anion (O(2)(.-)) generation. This prooxidant effect, observed in rat liver mitochondria and bovine heart particles, suggests DHLA-induced free radicals contribute to MPT.

Area of Science:

  • Mitochondrial Physiology
  • Oxidative Stress
  • Biochemistry

Background:

  • Dihydrolipoic acid (DHLA) is known to induce Ca(2+)-mediated mitochondrial permeability transition (MPT).
  • The prooxidant properties of DHLA have been suggested as a potential mechanism for MPT induction.

Purpose of the Study:

  • To investigate whether DHLA stimulates superoxide anion (O(2)(.-)) generation in mitochondria.
  • To elucidate the role of DHLA-induced prooxidants in the MPT process.

Main Methods:

  • Assay of O(2)(.-) generation in rat liver mitochondria (RLM) using lucigenin chemiluminescence.
  • Electron spin-trapping technique to detect radical generation in bovine heart submitochondrial particles (SMP).
  • Assessment of MPT inhibition by radical scavengers and mitochondrial membrane potential modulators.

Main Results:

  • DHLA induced a concentration-dependent O(2)(.-) generation in RLM, particularly with pyruvate as substrate.
  • DHLA also stimulated O(2)(.-) production in bovine heart SMP.
  • Radical scavengers and partial uncoupling agents inhibited DHLA-induced O(2)(.-) generation and MPT.

Conclusions:

  • DHLA-induced MPT is mediated by DHLA-derived prooxidants, specifically stimulated O(2)(.-) production.
  • These findings highlight the role of oxidative stress in DHLA's effect on mitochondrial function.

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