Responses of C-fiber low threshold mechanoreceptors and nociceptors to cold were facilitated in rats persistently inflamed and hypersensitive to cold
Responses of C-fiber low threshold mechanoreceptors and nociceptors to cold were facilitated in rats persistently inflamed and hypersensitive to cold
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DOI：
10.1016/j.neures.2003.08.003
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发表时间：
2003-12-01
影响因子：
2.9
通讯作者：
Mizumura, K
中科院分区：
文献类型：
--
作者：
Takahashi, K;Sato, J;Mizumura, K
冷痛是类风湿性关节炎等慢性炎症条件下的一种令人讨厌的症状。为了检验初级传入神经活动是否与冷过敏有关，我们在活体内记录了持续性炎症大鼠的单个腓肠神经活动。炎症是由完全弗氏佐剂(CFA)溶液注射到胫颧骨关节引起的。炎症大鼠在25℃的水中摇动爪子的次数增加(炎症前：1.15+/-0.58，2周炎症：4.70+/-1.15)。我们还记录了戊巴比妥钠麻醉下皮肤C纤维的活动，并研究了它们对热刺激和机械刺激的反应。C-低阈值机械感受器对冷(27~23℃总放电)的反应增加1.8倍(对照组：5.17+/-1.04个脉冲，炎症组：9.38+/-1.47个脉冲)。此外，炎症组(18个单位中有9个单位；阈值：10.0+/-2.6℃)对寒冷降温至2摄氏度的C-伤害性感受器单位的比例显著高于完好组(14个单位中有1个单位；阈值：4.0℃)。这些结果表明，这些初级传入的易化反应与慢性炎症条件下的冷过敏有关。(C)2003年爱思唯尔爱尔兰有限公司和日本神经科学学会。版权所有。
Cold allodynia is an annoying symptom in conditions of chronic inflammation such as rheumatoid arthritis. To examine whether primary afferent nerve activities are changed in association with hypersensitivity to cold, we recorded single nerve activities from the sural nerve in persistently inflamed rats in vivo. Inflammation was induced by an injection of complete Freund's adjuvant (CFA) solution into the tibio-tarsal joint. Inflamed rats showed an increased number of paw shakes to paw immersion in 25degreesC water (pre-inflammation: 1.15 +/- 0.58, 2-week inflammation: 4.70 +/- 1.15). We also recorded cutaneous C-fiber activities under pentobarbital anesthesia and studied their responses to thermal and mechanical stimuli. The response of C-low threshold mechanoreceptors to cooling (total discharges between 27 and 23degreesC) increased 1.8-fold (control group: 5.17 +/- 1.04 impulses, inflamed group: 9.38 +/- 1.47 impulses). In addition, the proportion of C-nociceptor units responding to cold down to 2degreesC was significantly greater in the inflamed group (9 out of 18 units; threshold: 10.0 +/- 2.6degreesC) than in the intact group (1 out of 14 units; threshold: 4.0degreesC). These results suggest that the facilitated responses of these primary afferents are associated with cold hypersensitivity in chronically inflamed conditions. (C) 2003 Elsevier Ireland Ltd and The Japan Neuroscience Society. All rights reserved.