Understanding Physiologic Mechanisms of Acupuncture: Inflammation, Neural Effects, and Beyond

1. Acupuncture Part 2 Physiologic Mechanisms

2. Physiologic Mechanism • Local inflammation and muscular effects • Neural (non-opioid) segmental gate theory • Neural (opioid) humeral theory • Somatovisceral (autonomic) effects • Bioelectrical theory

3. Local Effects: De Qi Sensation • Caused by sequential activation of • A-delta * • C-fiber * • Group II fiber * • Blocked by local anesthesia • Requires intact nervous system • Not seen at non-AP points

4. Local Effects: De Qi Sensation

5. Local Effects: De Qi • PRABM response in horses (pilomotor reaction along bladder meridian)

6. Local Effects • Muscle Reaction • contraction around the needle • ipsilateral flexion • contralateral extension • Leads to tissue relaxation and relief of muscle spasm • Principle of trigger point therapy

7. Local Effects • Anatomically, AP points are sensitive to microtrauma • Releases Hageman’s Factor XII • activates clotting cascade, complement cascade, plasminogen and kinins • Produces local PGs • Mast Cell degranulation • histamine, heparin and kinin protease • Releases Bradykinin

8. Local Effects: Event Sequence • Vasoconstriction 15-30 sec • Quasi-control 10 sec-2 min • Vasodilatation 2 min-2 wk •  local immune status •  local BF •  local muscle and tissue relaxation

9. Physiologic Mechanism • Local inflammation and muscular effects • Neural (non-opioid) segmental gate theory • Neural (opioid) humeral theory • Somatovisceral (autonomic) effects • Bioelectrical theory

10. Segmental Analgesia • Evoked by high frequency, low intensity stimulation of AP point • Rapid onset • Diminishes after cessation • Not reversed by naloxone

11. Types & Speed of Axons

12. Gate Theory of Melzack & Wall • A-delta fibers conduct information to spinal cord before slow conducting C fiber information arrives • These fibers lead to inhibition (pre-synaptic) of information carried by the C fibers (pain)

13. Gate Theory of Melzack & Wall • Fast transmitting fibers lead to pre-synaptic inhibition

14. Physiologic Mechanism • Local inflammation and muscular effects • Neural (non-opioid) segmental gate theory • Neural (opioid) humeral theory • Somatovisceral (autonomic) effects • Bioelectrical theory

15. Humeral Mechanisms • Interaction of AP point with • Spinal Cord • Brainstem • Higher Centers • Mediated through neurochemical interactions

16. Opioid Humeral Mechanisms • Take 30-40 minutes • Persists for hours • Generalized effect which is reversed by naloxone • Transferable from one patient to another • Tolerance to and cross tolerance with morphine develops

17. Opioid Humeral Mechanisms • Dexamethasone  ß-endorphin levels and  AP analgesia • Adrenalectomy  ß- endorphins and  AP analgesia • Hypophysectomy eliminates AP analgesia

18. 5HT Humeral Mechanisms • [5HT]  in systemic circulation by 30-40% following AP • CNS maintains balance between 5HT and ß-endorphins • endorphins alter 5HT release (regulating pain threshold in spinal cord) •  5HT blocks effects of naloxone

19. Potentiators of AP effects substance P histamine cGMP Antagonists of AP effects GABA cAMP Other Humeral Mechanisms

20. Humeral Mechanisms: Systemic Endocrine Effects • Improves BF to pituitary axis and  capillary wall [enzyme] • Releases somatotropin in chronic pain patients • Induces LH release • Stimulates prolactin and oxytocin release • Modulates thyroid function

21. Physiologic Mechanism • Local inflammation and muscular effects • Neural (non-opioid) segmental gate theory • Neural (opioid) humeral theory • Somatovisceral (autonomic) effects • Bioelectrical theory

22. Somatovisceral Reflex: Autonomic Effects • AP stimulation converges with visceral efferent resulting in reflexive interactions with internal organs (along internal connecting meridians) • Regionally located • Referred pain regions

23. Autonomic Effects • Indication of certain AP points correlate with symptoms for viscera at the same spinal segment • Bring descending influence only to the level of stimulation, ipsilaterally • Specificity of AP points related to somatotropic location

24. Autonomic Effects • Referred pain • Convergence of Somatic and Visceral inputs in CNS • dorsolateral funiculus • spinothalamic tracts • Visceral A-delta fibers reflexively affect muscles • inflammation and cramping

25. Autonomic Effects • AP of somatic structures can treat internal organs (through meridian connections) • AP modulates both arms of ANS • Segmental sympathetic vasodialation • Highly specific • Stimulate a specific AP point, get a specific physiologic change

26. Autonomic Effects • AP stimulation of GV26 altered BP, HR and RR in dogs undergoing induced shock • Mortality in controls = 100% • Mortality in AP-treated = 25%

27. Autonomic Effects • Stimulation of PC6 •  lipid peroxidation of the heart •  coronary blood flow • improved cardiac rhythm

28. Potentiators of AP effects ß-adrenergic * eserine Antagonists of AP effects -adrenergic * atropine Autonomic Effects

29. Physiologic Mechanism • Local inflammation and muscular effects • Neural (non-opioid) segmental gate theory • Neural (opioid) humeral theory • Somatovisceral (autonomic) effects • Bioelectrical theory

30. Bioelectric Theory • DC energy channels correspond to AP meridians • Points of low electrical resistance on the skin correspond to AP points • Acupuncture • AP point • Meridian • Qi • Bioelectric • Amplifier • Conductor • Bioelectricity

31. OtherAP Effects • Anti-fever • GI regulation • Anti-inflammation effect • Blood pressure regulation • Stress relief • Aging prevention • Performance enhancement • Improving microcirculation • Face lift

32. Transcutaneous Nerve Stimulation (TENS units) • Well accepted method to produce analgesia • Electrodes hard to apply to haired animals • May just be acupuncture without needles

33. Conclusions • AP represents part of an ancient system of comprehensive health care • As scientific knowledge expands, modern correlations are being developed which help translate this ancient wisdom into today's terms • May the Qi be with you!!!