Physical and Biological Concepts:
A substantial amount of literature and medical experts support the phenomena of using red and infrared light as a therapeutic approach to increase the rate of tissue repair and to reduce localized inflammation. The foremost of the investigators in the photo-biology/photo-stimulation field, Dr. Tina Karu, has undertaken carefully designed experiments on isolated nerve and tissue preparations which have yielded the following information:
“…Red light in the tissue transmission window between the reduced and oxyhemoglobin peaks at 620nm and 900nm is absorbed primarily by mitochondrial cytochromes and flavoproteins. The latter are essential coenzymes responsible for the transfer of hydrogenions to cytochrome complexes. The mitochondrial cytochromes perform the complementary oxidative phosphorylation function of electron transfer in the production of the energetic biochemical species ATP. Since ATP provides the biochemical energy for all cellular activities from transudation of receptor recognition events, through transactivation of gene transcription, message RNA translation into protein, and replication of the cell, a mechanism which modulates or “ pumps” ATP availability to the cell inevitably modulates its function. In as much as certain cells, such as lymphocytes, have very abundant oxidative enzyme complexes localized to their cytoplasmic membranes, and red light may be absorbed directly by these complexes, it is probable that these cells are directly activated by photostimulation…”
ILLUSTRATION: Dr. Tiina Karu and George Chew on low power laser therapy development in 1993, Toronto.
Action Modes:
1. Direct Response
Light absorption on cellular molecules in essence results in the transformation of light energy into biochemical energy. This effect requires sufficient stimulation to initiate a significant response. Effects occur at the molecular level with the restoration of normal function of the cell unit. Researchers have failed to record any negative effects from this process and normal functioning cells are not affected. (Ref: T.Karu). This mechanism directly enhances and/or stimulates the following cellular activities:
- protein synthesis (R.N.A., D.N.A.)
- A.T.P. production
- Mitochondrial division
- Cell metabolism
- Angiogenesis
- Phagocytosis
- Membrane pump function
- Nerve tissue response and transmission
- Photo-dissociation of oxyhemoglobin
- Cell replication
2. Indirect or Neurological Response
This can occur early in therapy and dramatic effects are often noted within minutes of initiating treatment. The response is similar to the acupuncture process as the stimulation of nerve ends in the area being treated. Impulses are transmitted to the central nerve system that affects the parasympathetic nervous system and the humoral-endocrine pathway. The result is an increased production of cortisol (the precursor of cortisone) and the release of endorphins. This process can immediately alleviate inflammation and pain.
3. Humoral Response
The vascular volume passes the active laser several
times per minute. This results in positive therapeutic effects relating
to the neurotransmitters, histamines and prostaglandins. In fact, many
researchers feel this will also enhance the body’s immune system and are
continuing to do further studies in laboratories.