Failure of narcotic antagonist to alter electroacupuncture modification of halothane anaesthesia in the dog

Abstract

Sixteen dogs were used to study the analgesic effects of electroacupuncture. Electroacu-puncture lowered halothane MAC significantly (1.21 ± 0.04 to 1.05 ± 0.05 per cent, p < 0.005). Reversibility of this effect by narcotic antagonist was then studied, using naltrexone 5mg.kg-1 injected intravenously (10 dogs) or 0.5mg kg-1 intrathecally (3 dogs). We failed to see any reversal of the effect of electroacupuncture on MAC. Narcotic antagonist reversibility of acupuncture effect is taken currently to imply endorphin mediation. Possible explanations for our result include an electroacupuncture analgesia not mediated by endorphins. © 1982 Canadian Anesthesiologists.