Mitochondrial threshold for H2O2 release in skeletal muscle of mammals

Mitochondrion. 2020 Sep:54:85-91. doi: 10.1016/j.mito.2020.07.005. Epub 2020 Jul 30.

Abstract

The aim of the study was to evaluate the interplay between mitochondrial respiration and H2O2 release during the transition from basal non-phosphorylating to maximal phosphorylating states. We conducted a large scale comparative study of mitochondrial oxygen consumption, H2O2 release and electron leak (% H2O2/O) in skeletal muscle mitochondria isolated from mammal species ranging from 7 g to 500 kg. Mitochondrial fluxes were measured at different steady state rates in presence of pyruvate, malate, and succinate as respiratory substrates. Every species exhibited a burst of H2O2 release from skeletal muscle mitochondria at a low rate of oxidative phosphorylation, essentially once the activity of mitochondrial oxidative phosphorylation reached 26% of the maximal respiration. This threshold for ROS generation thus appears as a general characteristic of skeletal muscle mitochondria in mammals. These findings may have implications in situations promoting succinate accumulation within mitochondria, such as ischemia or hypoxia.

Keywords: Allometry; Bioenergetics; Oxidative phosphorylation; Radical oxygen species; Skeletal muscle.

MeSH terms

  • Animals
  • Cattle
  • Cricetinae
  • Hydrogen Peroxide / analysis*
  • Mesocricetus
  • Mice
  • Mitochondria, Muscle / metabolism*
  • Muscle, Skeletal / cytology*
  • Muscle, Skeletal / metabolism
  • Oxidative Phosphorylation
  • Rabbits
  • Rats
  • Sheep

Substances

  • Hydrogen Peroxide