Nitric Oxide Regulates Mitochondrial Respiration and Cell Functions by Inhibiting Cytochrome Oxidase

FEBS Lett. 1995 Aug 7;369(2-3):136-9. doi: 10.1016/0014-5793(95)00763-y.


Nitric oxide (NO) reversibly inhibits mitochondrial respiration by competing with oxygen at cytochrome oxidase. Concentrations of NO measured in a range of biological systems are similar to those shown to inhibit cytochrome oxidase and mitochondrial respiration. Inhibition of NO synthesis results in a stimulation of respiration in a number of systems. It is proposed that NO exerts some of its main physiological and pathological effects on cell functions by inhibiting cytochrome oxidase. Further NO may be a physiological regulator of the affinity of mitochondrial respiration for oxygen, enabling mitochondria to act as sensors of oxygen over the physiological range.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Electron Transport Complex IV / antagonists & inhibitors*
  • Humans
  • Mitochondria / metabolism*
  • Muscle Contraction
  • Muscle Relaxation
  • Muscle, Skeletal / physiology
  • Muscle, Smooth / physiology
  • Nitric Oxide / metabolism
  • Nitric Oxide / physiology*
  • Oxidative Phosphorylation
  • Oxygen Consumption*


  • Nitric Oxide
  • Electron Transport Complex IV