title: Nicotinic acetylcholine receptor α7 subunit is involved in the cobratoxin-induced antinociception in an animal model of neuropathic pain.
abstract: In this study we report that cobratoxin (CbTX), a long-chain postsynaptic α-neurotoxin isolated from the Thailand cobra, Naja naja kaouthia, has antinociceptive effect in rats with neuropathic pain. The neuropathic pain model was established in rats with partial sciatic nerve ligature (PSNL) method. The pain response was examined behaviorally with mechanical paw withdrawal and thermal paw withdrawal method. Different doses (0.56, 1.12 and 4.50 μg/kg) of CbTX were injected intrathecally. Injection of CbTX resulted in a significant dose-dependent antinociception as evidenced by increased mechanical withdrawal threshold and thermal withdrawal latency. CbTX also induces a significant dose-dependent inhibition of pain-evoked unit discharges of thalamic parafascicular neurons. Both the behavioral mechanical and thermal antinociception and the inhibition of pain-evoked discharges of neurons in thalamic parafascicular nucleus in PSNL model could be mimicked by PUN282987, selective α7 nicotinic AChR (α7 nAChR) agonist and reversed by methyllycaconitine (MLA) selective α7 nAChR antagonist. In summary, these results suggested that AChR α7 subunit was involved in the antinociceptive action of CbTX for neuropathic pain and might be the candidate target for analgesic drug design.
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gong
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liang
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Dayong
authors.initials: D
authors.lastname: Ding
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Qizhang
authors.initials: Q
authors.lastname: Yin
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China.
authors.forename: Jin
authors.initials: J
authors.lastname: Tao
authors.affiliation: Department of Physiology and Neurobiology, Key Laboratory of Pain Research and Therapy, Medical College of Soochow University, PR China. Electronic address: jiangxinghong@suda.edu.cn.
authors.forename: Xinghong
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D003039:Cobra Neurotoxin Proteins / Q000008:administration & dosage / Q000378:metabolism* / Q000494:pharmacology*; D004195:Disease Models, Animal; D007278:Injections, Spinal; D008297:Male; D009437:Neuralgia / Q000188:drug therapy*; D051381:Rats; D017207:Rats, Sprague-Dawley; D064569:alpha7 Nicotinic Acetylcholine Receptor / Q000378:metabolism*
chemical_list: D000700:Analgesics; D003039:Cobra Neurotoxin Proteins; D064569:alpha7 Nicotinic Acetylcholine Receptor
keywords: Antinociception; Cobratoxin; Thalamic parafascicular nucleus; α7 nicotinic acetylcholine receptor