Laser energy is absorbed by metabolically active pigments of the mitochondria in various cutaneous and subcutaneous layers of the skin, which involves two enzymes of the oxidation chain – Cytochrome a/a3 and Flavoprotein. This leads to an increase in activity and improves the concentration of ATP by up to 200%. In addition an increase in oxygen and glucose metabolism is observed. A significant effect of cold laser therapy is an optimised function of the Na/K pump at the cell membrane, an increased protein synthesis (prostaglandin enzyme) and a significantly higher rate of mitosis.
Units of light energy (photons) are absorbed by enzymes which react to light within the cell. Visible light is absorbed within the mitochondria and infrared light is absorbed at the cell membrane. In a mammalian cell, this results in a change in the membrane permeability, increased ATP levels and increased DNA production. The photons picked up by the cell membrane result in improved membrane stability and increased activity of the ATP dependent Na/K pump. Because cell metabolism is influenced by Na/K movement across the membrane, increasing the gradient will affect the flow of ions and hence the overall metabolism of the cell.
On a tissue level, it has been shown that the irradiation by laser light results in increased collagen and epithelial production and production of new capillaries and an increase in density of the capillary bed. Reduction of pain and inflammation results from this treatment, as does the stimulation of nerve regeneration, muscle relaxation and atonicity (muscle tone).
Dr. Melyni Worth PhD, ‘Low level Laser Therapy provides New Treatment Possibilities’ (World Veterinary Review, Vol 3, No,3, 1998)