Acupoint stimulation with diluted bee venom (apipuncture) alleviates thermal hyperalgesia in a rodent neuropathic pain model: involvement of spinal alpha 2-adrenoceptors.
Chemical acupuncture with diluted bee venom (DBV), termed apipuncture, has been traditionally used in oriental medicine to treat several inflammatory diseases and chronic pain conditions. In the present study we investigated the potential antihyperalgesic and antiallodynic effects of apipuncture in a rat neuropathic pain model. DBV (0.25 mg/kg, subcutaneous) was injected into the Zusanli acupoint 2 weeks after chronic constrictive injury (CCI) of the sciatic nerve. Between 5 and 45 minutes after DBV injection, we observed a significant reduction in the thermal hyperalgesia induced by CCI, but apipuncture failed to reduce CCI-induced mechanical allodynia. We subsequently examined whether this antihyperalgesic effect of apipuncture was related to the activation of spinal opioid receptors and/or alpha2-adrenoceptors. Intrathecal pretreatment with naloxone (10 microg/rat), an opioid receptor antagonist, did not reverse the antihyperalgesic effect of apipuncture, whereas pretreatment with idazoxan (40 microg/rat), an alpha2-adrenoceptor antagonist, completely blocked the effect of apipuncture. These results indicate that DBV-induced apipuncture significantly reduces the thermal hyperalgesia generated by CCI and also suggest that this antihyperalgesic effect is dependent on the activation of alpha2-adrenoceptors, but not opioid receptors, in the spinal cord.


CONCLUSIONS
The antinociceptive effect of apipuncture was evaluated in a rodent neuropathic pain model. The relieving effect of apipuncture on thermal hyperalgesia was found to be mediated by spinal alpha2-adrenoceptors, but not opioid receptors. These data suggest that apipuncture might be an effective alternative therapy for patients with painful peripheral neuropathy, especially for those who are poorly responsive to opioid analgesics.
Roh
Dae-Hyun
DH
Department of Veterinary Physiology, College of Veterinary Medicine, Seoul National University, South Korea.
Kwon
Young-Bae
YB
Kim
Hyun-Woo
HW
Ham
Tae-Won
TW
Yoon
Seo-Yeon
SY
Kang
Seuk-Yun
SY
Han
Ho-Jae
HJ
Lee
Hye-Jung
HJ
Beitz
Alvin J
AJ
Lee
Jang-Hern
JH
D015669:Acupuncture Points; D018674:Adrenergic Antagonists / Q000494:pharmacology; D058669:Adrenergic alpha-2 Receptor Antagonists; D000818:Animals; D001514:Bee Venoms / Q000008:administration & dosage*; D004195:Disease Models, Animal; D006930:Hyperalgesia / Q000628:therapy*; D008297:Male; D059408:Pain Management; D051381:Rats; D017207:Rats, Sprague-Dawley; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*; D013116:Spinal Cord / Q000378:metabolism
D018674:Adrenergic Antagonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D001514:Bee Venoms; D018341:Receptors, Adrenergic, alpha-2