Photobiological modulation of cell attachment via cytochrome c oxidase

Photochem Photobiol Sci. 2004 Feb;3(2):211-6. doi: 10.1039/b306126d. Epub 2003 Nov 12.


The number of cells attached to glass substrates increases if HeLa cell suspensions are irradiated with monochromatic visible-to-near infrared radiation (600-860 nm, 52 J m(-2)) prior to plating. The well-structured relationship between this biological response and the radiation wavelength (action spectrum with maxima at 620, 680, 760, and 820 nm) suggests the existence of a photoacceptor responsible for the enhancement of attachment (presumably cytochrome c oxidase, the terminal enzyme of the respiratory chain) and, secondly, the existence of signaling pathways between the mitochondria, the plasma membrane, and the nucleus of the cell. Treating the cell suspension with ouabain (a Na(+), K(+)-ATPase inhibitor), amiloride (an inhibitor of N(+)/H(+) exchangers), or sodium azide (a cytochrome c oxidase inhibitor) prior to irradiation significantly modifies the action spectrum of cell attachment enhancement. The action of the chemicals under study also depends on their concentration and radiation fluence. Our results point to the existence of at least three signaling pathways (reaction channels) relating together the cell attachment, the respiratory chain, and the Na(+), K(+)-ATPase and N(+)/H(+) exchanger activities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amiloride / pharmacology
  • Cell Adhesion / physiology
  • Cell Adhesion / radiation effects*
  • Dose-Response Relationship, Radiation
  • Electron Transport Complex IV / antagonists & inhibitors
  • Electron Transport Complex IV / metabolism*
  • Electron Transport Complex IV / radiation effects
  • Enzyme Inhibitors / pharmacology
  • Glass
  • HeLa Cells
  • Humans
  • Light
  • Ouabain / pharmacology
  • Sodium Azide / pharmacology
  • Sodium-Hydrogen Exchangers / antagonists & inhibitors
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors
  • Time Factors


  • Enzyme Inhibitors
  • Sodium-Hydrogen Exchangers
  • Ouabain
  • Amiloride
  • Sodium Azide
  • Electron Transport Complex IV
  • Sodium-Potassium-Exchanging ATPase