Anales RANF

Simposium 17: ACUPUNCTURE AND PURINERGIC MECHANISM Chair: Yong Tang (Chengdu, China) Content : Acupuncture is a Traditional Chinese Medicinal Therapy commonly used to combat pathological conditions notably pain. In 2009, the purinergic hypothesis of acupunctural analgesia was proposed by Geoffrey Burnstock: sensory nerve activity initiated in the skin by acupuncture would exert an inhibitory modulating effect on the spinoparabrachial and spinothalamic tracts to the brain pain centers. The hypothesis is supported by the early pharmacological finding that adenosine receptor antagonists theophylline and caffeine blocked the acupuncture-induced elevation of the nociceptive threshold. In 2010, the study by Maiken Nedergaard and colleagues provides the direct evidence that the acupuncture-released ATP is degraded to adenosine to produce analgesia via activation of adenosine A1 receptors. Since then, increasing evidence has demonstrated that purinergic signaling represent an important and crucial mechanism underlying the acupunctural analgesia. However, many central questions remain to be addressed experimentally to uncover the mode of the action of acupuncture. For example, are there dynamic changes in the concentrations of purines (ATP, ADP, AMP, adenosine) following acupuncture at the puncture site as well as pain-relevant areas of the brain? Is acupunctural analgesia mediated by purinergic signal at peripheral or central nerve systems? In addition to the A1 receptor, what are the contribution of other adenosine (such as A2A) and P2 receptors (such as P2X3, P2X4, and P2X7Rs) to acupunctural analgesia? Does purinergic signal interact with other nociceptive neuromodulators/receptors to modify acupunctural analgesia? This proposed symposium seeks to address these critical issues by scientists from multi- disciplines to provide the new insights into the purinergic mechanisms of acupuncture analgesia.