Gc. Wu et al., INVOLVEMENT OF OPIOID-PEPTIDES OF THE PREOPTIC AREA DURING ELECTROACUPUNCTURE ANALGESIA, Acupuncture & electro-therapeutics research, 20(1), 1995, pp. 1-6
The present work was to study the roles of opioid peptides in the preo
ptic area on electroacupuncture analgesia (EA), and the effects of opi
oid peptides on noradrenaline (NA) release in the preoptic area during
EA. It was found that the pain threshold and the level of [Leu(5)] en
kephalin (L-EK) or beta-endorphin (beta-EP) release in the perfusate w
ere increased during EA, but the NA release from the preoptic area was
decreased. Naloxone (15 mu M) perfusion significantly reversed the in
creased pain threshold and the decreased NA release induced by acupunc
ture. The reversal of pain threshold and NA release by naloxone was do
se-dependent. Multimicropipettes and microiontophoresis were also used
to study the effect of acupuncture. The inhibition of nociceptive neu
ronal discharges produced by electroacupuncture was closely related to
the etorphine-sensitive neurons, and reversed by microiontophoretic a
pplication of naloxone. The results suggest that the inhibitory effect
induced by electroacupuncture may be mediated by opioid peptides in t
he preoptic area.