ANGIOTENSINERGIC MECHANISMS OF AURICULAR ACUPUNCTURE DENTAL ANALGESIA

Two basic neurochemical mechanisms of acupuncture analgesia are now known: opioid and serotoninergic [1], and which mechanism is activated depends on the frequency of acupuncture stimulation [4]. It has been shown, for instance, that the analgesic effects of acupuncture stimulation (APS) with a frequency of 1-30 Hz are blocked by naloxone [1,2,10] and are reduced by a serotonin blocker [8], whereas the effects of APS with a frequency of 100 Hz or more are not blocked by naloxone, as has been shown by the action of thermal and electrodental (EDS) nociceptive stimuli [2,10]. At the same time, injection of angiotensin II (AII) is known to have an analgesic effect also against nociceptive stimulation of the dental pulp in rabbits [3,9] and thermal stimulation of the skin in rats [5]. The aim of this investigation was to study the role of AII in the analgesic effects of auricular acupuncture electrostimulation (AAS) with a frequency of 15 and 100 Hz, relative to changes in the amplitude of EP of the somatosensory cortex in response to nociceptive electrical stimulation of the dental pulp in rabbits, an objective indicator of a change in the pain sensitivity of man [6] and animals [1, 7].