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Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
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Nitric oxide inhibition of mitochondrial respiration and its role in cell death

Guy C Brown1, Vilmante Borutaite

  • 1Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom. gcb@mole.bio.cam.ac.uk

Free Radical Biology & Medicine
|November 26, 2002
PubMed

Insights

Nitric oxide (NO) and reactive nitrogen species (RNS) impair mitochondrial respiration through reversible and irreversible mechanisms, impacting cell death pathways. These processes can lead to necrosis or apoptosis, depending on cellular context and energy metabolism.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Toxicology

Background:

  • Mitochondrial respiration is crucial for cellular energy production.
  • Nitric oxide (NO) and reactive nitrogen species (RNS) are signaling molecules with complex roles in cell physiology.
  • Dysregulation of mitochondrial function is implicated in various pathologies.

Purpose of the Study:

  • To elucidate the distinct mechanisms by which NO and RNS inhibit mitochondrial respiration.
  • To explore the consequences of respiratory inhibition on cell death pathways, including necrosis and apoptosis.
  • To understand the role of NO and RNS in neuronal excitotoxicity.

Main Methods:

  • The study likely involved biochemical assays to measure mitochondrial respiration and enzyme activity.
  • Cellular models were probably used to assess cell viability, apoptosis, and necrosis.
  • Investigated the interaction of NO/RNS with specific respiratory chain components.

Main Results:

  • NO reversibly inhibits cytochrome oxidase by competing with oxygen.
  • RNS irreversibly inhibit multiple sites within the mitochondrial respiratory chain.
  • Inhibition of respiration can lead to ATP depletion, causing necrosis or inhibiting apoptosis.
  • Neuronal respiration inhibition can trigger excitotoxic neuronal death via glutamate release.

Conclusions:

  • NO and RNS exert dual inhibitory effects on mitochondrial respiration.
  • Respiratory inhibition by NO/RNS has complex and context-dependent effects on cell death.
  • NO/RNS-induced cell death involves mechanisms beyond direct respiratory inhibition.

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