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Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals
05:59

Oxygen-Independent Assays to Measure Mitochondrial Function in Mammals

Published on: May 19, 2023

There is no evidence that mitochondria are the main source of reactive oxygen species in mammalian cells

Guy C Brown1, Vilmante Borutaite

  • 1Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.

Mitochondrion
|February 10, 2011
PubMed

Insights

Mitochondria are not definitively the primary source of reactive oxygen species (ROS) in cells. Other organelles like the endoplasmic reticulum and peroxisomes may produce more ROS, and mitochondria can also degrade ROS.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Physiology

Background:

  • Mitochondria are widely assumed to be the main source of reactive oxygen species (ROS) in mammalian cells.
  • Existing evidence suggests mitochondria are a significant source of ROS, impacting cellular functions.
  • The precise contribution of mitochondria to overall cellular ROS production remains unclear.

Purpose of the Study:

  • To critically evaluate the evidence for mitochondria as the primary source of cellular ROS.
  • To compare the ROS-producing capacity of mitochondria with other cellular organelles.
  • To investigate the dual role of mitochondria as potential ROS sources and sinks.

Main Methods:

  • Literature review and critical analysis of experimental data.
  • Quantitative assessment of ROS production by different organelles (e.g., liver cells).
  • Evaluation of mitochondrial capacity for ROS degradation.

Main Results:

  • There is a lack of convincing experimental evidence supporting mitochondria as the main ROS source.
  • Endoplasmic reticulum and peroxisomes demonstrate a greater quantitative capacity for ROS production than mitochondria, particularly in liver cells.
  • Mitochondria possess a significant capacity to degrade ROS, acting as potential sinks.

Conclusions:

  • The assumption of mitochondria being the main cellular ROS source is not well-supported by current evidence.
  • The relative contribution of mitochondria to cellular ROS levels as a net source or sink is condition-dependent and largely unknown.
  • Further research is needed to elucidate the precise role of mitochondria in cellular redox homeostasis.

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