Cellular mechanisms of low-power laser therapy

Cytochrome c oxidase is considered as the photoacceptor when eukaryotic cells' are exposed to monochromatic red to near-IR radiation. Five primary mechanisms are discussed: changes in the redox properties of the respiratory chain components following photoexcitation of their electronic states, NO release from catalytic centre of cytochrome c oxidase, generation of singlet oxygen, localized transient heating of absorbing chromophores, in creased superoxide anion production with a subsequent increase in the concentration of H2O2. A cascade of reactions related to the alteration of cellular homeostasis parameters (pH(i), [Ca-i], cAMP, Eh, [ATP] and some others) is considered as a photosignal transduction and amplification chain in a cell (secondary mechanisms).