Acupuncture, adenosine and back pain

Back pain is one of the most frequent complaints. It is reported that one third of the people living in the UK are affected by low back pain. In the UK back pain is estimated to cost the economy over £12 billion per year and place a huge burden on society. Back pain usually originates from the muscles, nerves, bones and joints or other structures in the spine. Acute or short-term low back pain generally lasts from a few days to a few weeks. Most acute back pain is the result of trauma to the lower back or a disorder such as arthritis. Pain from trauma may be caused by a sports injury, work around the house or in the garden, or a sudden jolt such as a car accident or other stress on spinal bones and tissues. Symptoms may range from muscle ache to shooting or stabbing pain, limited flexibility and range of motion, or an inability to stand straight. Chronic back pain is pain that persists for more than 3 months. It is often progressive and the cause can be difficult to determine.

Although acupuncture is very effective in alleviating back pain in many patients its mechanisms of acupuncture-mediated analgesia has not been fully understood. It has been suggested that primary mechanism implicated in the anti-nociceptive effect of acupuncture involves release of opioid peptides in the central nervous system in response to long lasting activation of ascending tracts during intermittent stimulation. However, acupuncture is conventionally applied in close proximity to the locus of pain and analgesia is restricted to the ipsilateral side, indicating a peripheral and local action of acupuncture. Recent studies found that acupuncture stimulation at Zusanli on human subjects and pain models triggers increase in interstitial adenosine, a pain relieving substance, which reduce the severity of pain through activation adenosine A1 receptors. However acupuncture stimulation at the control point, 2 cm lateral to Zusanli acupoint did not elevate the interstitial levels of adenosine.

These studies together with other reports suggest that acupuncture stimulation at specific acupoints, on the one hand increase local adenosine level, on the other hand release opioid peptide in the brain, leading to the long lasting anti-nociceptive effect.

Reference:

T Takano et al., (2012) The Journal of Pain, Vol 13:1215-1223. http://www.ncbi.nlm.nih.gov/pubmed/23182227