Med Hypotheses. 1977 Jul-Aug; 3(4): 144-5.

The possible role of enkephalin in the mechanism of acupuncture analgesia in man.

Mendelson G.

On the basis of recent research on the presence and function of an endogenous peptide with opiate-like activity present in the brain, and the developing understanding of the physiological mechanism of acupuncture analgesia, it is postulated that the analgesic effects of acupuncture are mediated through the action of this substance on the neural mechanism(s) of pain inhibition.