Laser Mechanisms of Action
1. Enhancement of ATP production and synthesis
* ATP production and synthesis are significantly enhanced, contributing to cellular repair, reproduction and functional ability
* Photonic stimulation of Cytochrome c Oxidase, a chromophore found on the mitochondria of cells, plays a major role in this rapid increase in production and synthesis of ATP.
2. Stabilization of the cellular membrane
* Ca++, Na+ and K+ concentrations, as well as the proton gradient over the mitochondria membrane are positively influenced.
* This is accomplished in part, by the production of beneficial Reactive Oxygen Species aka (ROS).
* These ROS’s modulate intracellular Ca++ concentrations and laser therapy improves Ca++ uptake in the mitochondria.
3. Stimulation of vasodilation
* Vasodilation is stimulated via an increase in Histamine, Nitric Oxide (NO) and Serotonin levels, resulting in reduction of ischemia and improved perfusion
* Laser-mediated vasodilation enhances the transport of nutrients and oxygen to the damaged cells and facilitates repair and removal of cellular debris.
4. Acceleration of leukocytic activity
* Beneficial acceleration of leukocytic activity, resulting in enhanced removal of non-viable cellular and tissue components.
* Thus allowing for a more rapid repair and regeneration process.
5. Increased prostaglandin synthesis
* Prostaglandins have a vasodilating and anti-inflammatory action
6. Reduction in interleukin 1
* Laser irradiation has a reducing effect on this pro-inflammatory cytokine that has been implicated in the pathogenesis of rheumatoid arthritis and other inflammatory conditions.
7. Enhanced lymphocyte response
* In addition to increasing the number of lymphocytes, laser irradiation mediates the action of both lymphatic helper T-cells and suppressor T-cells in the inflammatory response.
* Along with laser modification of beta cell activity, the entire lymphatic response is beneficially affected by laser therapy.
8. Increased angiogenesis
* Both blood capillaries and lymphatic capillaries have been clinically documented to undergo significant increase and regeneration in the presence of laser irradiation.
9. Temperature modulation
* Areas of inflammation typically demonstrate temperature variations, with the inflamed portion having an elevated temperature.
* Laser therapy has been shown to accelerate temperature normalization, demonstrating a beneficial influence on the inflammatory process.
10. Enhanced superoxide dismutase (SOD) levels
* Laser stimulated increases in cytokine SOD levels interact with other anti-inflammatory processes to accelerate the termination of the inflammatory process.
11. Decreased C-reactive protein and neopterin levels
* Laser therapy has been shown to lower the serum levels of these inflammation markers, particularly in rheumatoid arthritis patients
12. Increase in beta endorphins
* The localized and systemic increase of this endogenous peptide, after laser therapy irradiation has been clinically reported in multiple studies, to promote pain reduction.
13. Increased nitric oxide production
* Nitric oxide has both a direct and indirect impact on pain sensation. As a neurotransmitter, it is essential for normal nerve cell action potential in impulse transmission activity.
* And indirectly, the vasodilation effect of nitric oxide can enhance nerve cell perfusion and oxygenation.
14. Decreased bradykinin levels
* Since Bradykinins elicit pain by stimulating nociceptive afferents in the skin and viscera, mitigation of elevated levels through laser therapy can result in pain reduction.
15. Ion channel normalization
* Photobiomodulation promotes normalization in Ca++, NA+ and K+ concentrations, resulting in pain reduction as a result of these ion concentration shifts.
16. Blocked depolarization of C-fiber afferent nerves
* The pain blocking effect of therapeutic lasers can be pronounced, particularly in low velocity neural pathways, such as non-myelinated afferent axons from nociceptors.
* Laser irradiation suppresses the excitation of these fibers in the afferent sensory pathway.
17. Increased nerve cell action potentials
* Healthy nerve cells tend to operate at about -70 mV, and fire at about -20 mV. Compromised cell membranes have a lowered threshold as their resting potentials average around this -20 mV range.
* That means that normal non-noxious activities produce pain.
* Laser therapy can help restore the action potential closer to the normal -70 mV range.
18. Increased release of acetylcholine
* By increasing the available acetylcholine, Laser Therapy helps in normalizing nerve signal transmission in the autonomic, somatic and sensory neural pathways.
19. Axonal sprouting and nerve cell regeneration
* Several studies have documented the ability of laser therapy to induce axonal sprouting and some nerve regeneration in damaged nerve tissues.
* Where pain sensation is being magnified due to nerve structure damage, cell regeneration and sprouting may assist in reducing pain.