Central neurotransmitters and acupuncture analgesia.

The role played by central neurotransmitters in acupuncture analgesia was evaluated by correlating neurochemical changes in central nervous system with the acupuncture effect, as well as modification of the acupuncture effects by pharmacological manipulations of central neurotransmitters. The results of experimental studies which were performed mainly on rats and rabbits indicated that central serotonin and endogenous opiate-like substances (OLS) seem to be the most important substrates for mediation of acupuncture analgesia while central catecholamines, especially norepinephrine through alpha receptors, may exert an antagonistic effect. It was also found that prolonged and repeated acupuncture resulted in a gradual decrease of the acupuncture effects. The development of some endogenous anti-opiate substrates (AOS) in central nervous system was tentatively implicated.