Impaired diffuse noxious inhibitory controls in specific alternation of rhythm in temperature-stressed rats
Impaired diffuse noxious inhibitory controls in specific alternation of rhythm in temperature-stressed rats
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DOI：
10.1016/j.ejphar.2016.05.011
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发表时间：
2016-08-05
影响因子：
5
通讯作者：
Kawamura, Toru
中科院分区：
文献类型：
--
作者：
Itomi, Yasuo;Tsukimi, Yasuhiro;Kawamura, Toru
纤维肌痛的特征是慢性广泛性肌肉骨骼疼痛。下行疼痛抑制系统功能低下被认为与纤维肌痛的慢性疼痛有关。我们通过测量弥漫伤害性抑制对照(DNIC)的强度，检测了特定温度节律变化(SART)应激大鼠下行疼痛抑制系统的功能变化。用后爪对机械von Frey细丝的抽离阈值或由Neuroeter系统提供的纤维特异性电刺激来测量疼痛反应。为诱导DNIC，将辣椒素注射到前爪的足底内。反复冷应激4d建立应激大鼠模型。在对照大鼠中，异位足底注射辣椒素提高了戒断阈值，表明DNIC有镇痛作用。在von Frey实验中，阿片受体拮抗剂纳洛酮、鞘内注射α2受体拮抗剂育亨宾和鞘内注射5-HT1a受体拮抗剂Way-100635均可降低DNIC的强度。在SART应激大鼠中，辣椒素注射没有提高von Frey测试中的戒断阈值，这表明DNIC存在缺陷。在神经计测试中，SART应激大鼠的DNIC不足，仅观察到A-增量和C-纤维，而没有A-β纤维的刺激。SART应激组大鼠侧脑室注射吗啡的镇痛作用明显低于对照组。综上所述，在SART应激大鼠，辣椒素诱导的DNIC存在缺陷，阿片介导的中枢痛觉调制系统功能低下可能导致DNIC缺陷。(C)2016爱思唯尔B.V.保留所有权利。
Fibromyalgia is characterized by chronic widespread musculoskeletal pain. A hypofunction in descending pain inhibitory systems is considered to be involved in the chronic pain of fibromyalgia. We examined functional changes in descending pain inhibitory systems in rats with specific alternation of rhythm in temperature (SART) stress, by measuring the strength of diffuse noxious inhibitory controls (DNIC). Hindpaw withdrawal thresholds to mechanical von Frey filament or fiber-specific electrical stimuli by the Neurometer system were used to measure the pain response. To induce DNIC, capsaicin was injected into the intraplantar of the forepaw. SART-stressed rats were established by exposure to repeated cold stress for 4 days. In the control rats, heterotopic intraplantar capsaicin injection increased withdrawal threshold, indicative of analgesia by DNIC. The strength of DNIC was reduced by naloxone (mu-opioid receptor antagonist, intraperitoneally and intracerebroventricularly), yohimbine (alpha 2-adrenoceptor antagonist, intrathecally), and WAY-100635 (5-HT1A receptor antagonist, intrathecally) in the von Frey test. In SART-stressed rats, capsaicin injection did not increase withdrawal threshold in the von Frey test, indicating deficits in DNIC. In the Neurometer test, deficient DNIC in SART-stressed rats were observed only for A delta- and C-fibers, but not A beta-fibers stimulation. Analgesic effect of intracerebroventricular morphine was markedly reduced in SART-stressed rats compared with the control rats. Taken together, in SART-stressed rats, capsaicin-induced DNIC were deficient, and a hypofunction of opioid-mediated central pain modulation system may cause the DNIC deficit. (C) 2016 Elsevier B.V. All rights reserved.