At the end of the electron transport chain there is an enzyme known as Cytochrome C Oxidase (CcO), which is the primary site of cellular oxygen consumption. It is here where the oxygen atom needs to attach to finish the last step of ATP production and generate energy. Unfortunately, due to diet and lifestyle, there can be more free radicals inside the cell than oxygen. One of these free radical molecules is nitric oxide (NO). This molecule, having an unpaired electron on its outer layer, has a higher affinity for the CcO enzyme than oxygen so it attaches there first. Once NO is attached to this enzyme, oxygen cannot attach and the ATP process cannot be completed. Photobiomodulation unbinds NO from the CcO enzyme allowing an oxygen atom to bind to the enzyme and complete the ATP process. The now free and unstable (high affinity to attach to other molecules) NO can bind to other molecules in the body. For example, by binding to soluble guanylate cyclase (sGC), NO produces a vasodilator effect. This can increase regional blood flow to an area of interest, such as the ovaries, the testes, or even the penis in case of erectile dysfunction. 

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Amongst the many studies and research papers on the topic of red light therapy and its benefits on mitochondria, they all seem to agree that photobiomodulation can free up the CcO enzyme from NO, allowing for oxygen to occupy that site. A review published in 2014 by Lasers in Medical Science, a peer-reviewed medical journal covering laser medicine, explains that:

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“ Light can indeed reverse the inhibition caused by NO binding to cytochrome oxidase, both in isolated mitochondria and in whole cells.”

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To learn more about red light therapy read my blog.

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