Intravenous morphine does not modify dorsal horn touch-evoked allodynia in the mononeuropathic rat: a Fos study
Intravenous morphine does not modify dorsal horn touch-evoked allodynia in the mononeuropathic rat: a Fos study
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DOI：
10.1016/s0304-3959(01)00283-4
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发表时间：
2001-06-01
期刊：
影响因子：
7.4
通讯作者：
Besson, JM
中科院分区：
文献类型：
--
作者：
Catheline, G;Le Guen, S;Besson, JM
在单神经性疼痛（坐骨神经慢性压迫性损伤，CCI）的模型中，我们已经证明对爪的轻触刺激（抚摸）在大鼠脊髓的浅表和深背角中诱导Fos样免疫反应性（Fos-LI）（Catheline等人，Pain 80（1999 a）347）。阿片类药物在神经病理性疼痛中的功效是有争议的，我们已经测试了吗啡（0.3、1和3 mg/kg静脉内，i. v.）在这个脊髓Fos-LI诱发的光触觉刺激，这可能与机械异常性疼痛。吗啡没有改变CCI大鼠在轻触刺激后观察到的脊髓Fos-LI水平（三种剂量分别为43 +/- 3、38 +/- 7和37 +/- 4个Fos-LI神经元/40 mum L4-L5切片，而对照组为32 +/- 4）。与此相反，静脉注射3 mg/kg吗啡使CCI大鼠热刺激（52 ℃，15 s持续时间）诱导的Fos-LI神经元数量减少30%（P < 0.05），与假手术大鼠相同。这些作用可通过纳洛酮全身给药逆转。吗啡对浅背角触觉诱发的Fos-LI缺乏影响，这加强了动态机械异常性疼痛与A-P纤维传递的信息有关的论断，因为阿片受体主要位于薄的初级传入纤维上。我们的研究结果提供了一个基础，某种形式的异常性疼痛是不敏感的吗啡。(C)2001年国际疼痛研究协会。由Elsevier Science B. V.出版，版权所有。
In a model of mononeuropathic pain (chronic constriction injury of the sciatic nerve, CCI), we have demonstrated that light touch stimuli (stroking) to the paw induced Fos-like immunoreactivity (Fos-LI) in the superficial and deep dorsal horn of the rat spinal cord (Catheline et al., Pain 80 (1999a) 347). The efficacy of opioids in neuropathic pain being controversial, we have tested the effects of morphine (0.3, 1 and 3 mg/kg intravenous, i.v.) on this spinal Fos-LI evoked by light tactile stimuli, which could be related to mechanical allodynia. Morphine did not change the level of spinal Fos-LI observed following light touch stimuli in the CCI rats (43 +/- 3, 38 +/- 7, and 37 +/- 4 Fos-LI neurones/40 mum L4-L5 section, respectively, for the three doses versus 32 +/- 4 in the control group). In contrast, the administration of 3 mg/kg of i.v. morphine reduced by 30% the number of Fos-LI neurones induced by heat stimulation (52 degreesC, 15 s duration) in CCI rats (P < 0.05) as in sham-operated rats. These effects were reversed by the systemic administration of naloxone. The lack of effect of morphine on touch-evoked Fos-LI in the superficial dorsal horn reinforces the assertion that dynamic mechanical allodynia is related to information transmitted by A-P fibres, since opioid receptors are mainly located on thin primary afferent fibres. Our results provide a basis for a certain form of allodynia that is insensitive to morphine. (C) 2001 International Association for the Study of Pain. Published by Elsevier Science B.V. All rights reserved.