Are the mitochondrial respiratory complexes blocked by NO the targets for the laser and LED therapy?

Lasers Med Sci. 2015 Jan;30(1):173-80. doi: 10.1007/s10103-014-1639-8. Epub 2014 Aug 14.


Effects of laser (442 and 532 nm) and light-emitting diode (LED) (650 nm) radiation on mitochondrial respiration and mitochondrial electron transport rate (complexes II-III and IV) in the presence of nitric oxide (NO) were investigated. It was found that nitric oxide (300 nM-10 μM) suppresses mitochondrial respiration. Laser irradiation of mitochondria (442 nm, 3 J cm(-2)) partly restored mitochondrial respiration (approximately by 70 %). Irradiation with green laser (532 nm) or red LED (650 nm) in the same dose had no reliable effect. Evaluation of mitochondrial electron transport rate in complexes II-III and IV and effects of nitric oxide demonstrated almost similar sensitivity of complex II-III and IV to NO, with approximately 50 % inhibition at NO concentration of 3 μM. Subsequent laser or LED irradiation (3 J cm(-2)) showed partial recovery of electron transport only in complex IV and only under irradiation with blue light (442 nm). Our results support the hypothesis of the crucial role of cytochrome c oxidase (complex IV) in photoreactivation of mitochondrial respiration suppressed by NO.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electron Transport Complex II / antagonists & inhibitors
  • Electron Transport Complex II / metabolism*
  • Electron Transport Complex III / antagonists & inhibitors
  • Electron Transport Complex III / metabolism*
  • Electron Transport Complex IV / antagonists & inhibitors
  • Electron Transport Complex IV / metabolism*
  • Lasers, Gas
  • Low-Level Light Therapy*
  • Male
  • Mitochondria, Liver / metabolism*
  • Mitochondria, Liver / radiation effects
  • Nitric Oxide / pharmacology*
  • Oxygen Consumption
  • Rats


  • Nitric Oxide
  • Electron Transport Complex II
  • Electron Transport Complex IV
  • Electron Transport Complex III