The Physiology of LLLT

Low level laser therapy (LLLT) works on an intracellular level. I have summarised the basic physiology of LLLT below in its barest form, so that anyone can grasp the science. For a more detailed discussion of the Basic Science of LLLT.

  • Light in the near-infrared and infrared (600-1100nm) spectrum is capable of being absorbed, imparting energy to and temporarily deforming certain proteins and biochemicals.
  • Light diffuses in translucent material like flesh and bone, limiting the depth to which it may penetrate.
  • More coherent light i.e from a laser, penetrates deeper into translucent material.
  • Stressed, ischaemic and hypoxic cells produce and are permeated with inflammatory markers including nitric oxide.
  • Nitric oxide (NO) binds with oxygen receptors and in particular the oxygen receptor on cytochrome C oxidase (COX).
  • COX is a intramembranous protein within mitochondria (the powerplant organelle within the cell).  It is the fourth and penultimate link in the electron transfer chain which produces the fuel for cellular processes: ATP.
  • When NO is bound to COX the electron transfer chain upstream of COX continues to produce substrates for the production of ATP. These substrates are reactive oxygen species (ROS) or free radicals.
  • Without ATP cellular processes stop.
  • ROS cause intracellular cascades that may damage everything within the cell including nucleic DNA.
  • Near-infrared light deforms COX changing the shape of its oxygen receptor allowing the release of bound NO. When COX releases NO, it may return to accepting oxygen and producing ATP, and stops producing free radicals.
  • LLLT can take cells that are functioning inefficiently or even on the point of apoptosis (cell death) and return them to normal function.