Reference to these points is related on one hand to the topographical paradox of the points and on the other to their important therapeutic action. In recent years, the analgesic action of acupuncture is used for the treatment of cases with acute or chronic pain and less for the surgical analgesia it can offer influencing the chemistry of the descending pain control system. Each system uses differente types of endogenous opioid peptides. There is clear evidence of the analgesic action of acupuncture in this field. The most important among these articles concern laboratory studies on experimental animals and clinical studies in veterinarian clinics.
Naloxone abolishes the analgesic effect.
Mice with a genetically reduced concentration of opiate receptors in the CNS have a poor response to acupuncture. Rabbits with endorphin deficiency do not respond to the acupuncture stimulus. Endorphin levels increase considerably in peripheral blood and in the cerebrospinal fluid during electro-acupuncture while on the contrary their levels in the CNS are reduced. The analgesic effect of acupuncture lasts much more when one impedes the enzymatic degradation of endorphin. The inhibition of pituitary endorphin abolishes the acupuncture effect.