Effects of pertussis toxin on electroacupuncture-produced anti-hyperalgesia in inflamed rats.
Our previous study showed that electroacupuncture (EA) significantly attenuated hyperalgesia in an animal model of persistent inflammatory pain. The present study was designed to show if Gi/o protein is involved in EA-produced anti-hyperalgesia. Spinal Gi/o-protein function was destroyed by intrathecal pretreatment with pertussis toxin (PTX). Seven days after the placement of an intrathecal PE-10 tube, PTX was injected into the intrathecal space of the lumbar spinal cord of rats. Seven days after PTX, complete Freund's adjuvant (CFA) was injected into the plantar surface of one hind paw of the rat to induce hyperalgesia in the injected paw. EA treatment was given at acupoint GB30 immediately post-CFA and then hyperalgesia was assessed by measuring the degree of decreased paw withdrawal latency (PWL) to a noxious thermal stimulus. The results showed that PTX pretreatment prevented EA-produced anti-hyperalgesia in the CFA inflammatory pain model but did not affect either baseline pain threshold or CFA-induced hyperalgesia. The data suggest that EA-produced anti-hyperalgesia is mediated by PTX-sensitive Gi/o proteins and the relevant signaling pathways.
Liu
Bing
B
Center for Integrative Medicine, James Kernan Hospital Mansion, 2200 Kernan Drive, Baltimore, MD 21207, USA.
Zhang
Rui-Xin
RX
Wang
Linbo
L
Ren
Ke
K
Qiao
Jian-Tian
JT
Berman
Brian M
BM
Lao
Lixing
L
D000818:Animals; D001522:Behavior, Animal; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D015671:Electroacupuncture / Q000379:methods*; D005620:Freund's Adjuvant; D006930:Hyperalgesia / Q000209:etiology / Q000628:therapy*; D007150:Immunohistochemistry / Q000379:methods; D007249:Inflammation / Q000139:chemically induced / Q000150:complications / Q000628:therapy*; D007278:Injections, Spinal / Q000379:methods; D037102:Lectins / Q000378:metabolism; D008297:Male; D010147:Pain Measurement; D037342:Pertussis Toxin / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects / Q000528:radiation effects; D013373:Substance P / Q000378:metabolism
D037102:Lectins; D013373:Substance P; D005620:Freund's Adjuvant; D037342:Pertussis Toxin; D015740:Calcitonin Gene-Related Peptide