Effects of orofacial pain on mastication estimated by expression of c-fos-like immunoreactivity in the rat trigeminal caudalis.

1.在氯醛糖麻醉的Wister大鼠切牙牙龈内注射0.05 μ g白细胞介素-1-β（IL-1b）或施加压力机械刺激后，观察三叉神经尾侧核c-fos样免疫反应（For-IR）的表达。IL-1b诱导的Fos-IR（IL-1b）在注射后早期被非甾体抗炎药（NSAIDS）抑制。结果提示，牙周病部位少量的IL-1b可诱导痛处理神经元中Fos-IR的表达。2研究了谷氨酸受体拮抗剂和激动剂对牙髓刺激后Fos-IR表达的影响。刺激前10 min鞘内注射MK-801、CNQX、AP-3、NMDA、AMPA和佛波酯（0.2 ms，0.6 mA，0.5 Hz，10 min），刺激后2 h观察各组对尾侧肌Fos IR表达的影响。结果表明，通过NMDA受体的Ca^<2+>内流对c-Fos的诱导和持续性疼痛的发展至关重要。

1 The expression of c-fos-like immunoreactivity (For-IR) was studied in the trigeminal caudalis of the chloralose anesthetized Wister rats after injection of 0.05 ug of interleukin-1-bata (IL-1b) into the gingiva of the incisor or application of the orthodontical mechanical stimulation. IL-1b injection-induced Fos-IR (IL-1b) was suppressed by administration of non-steroidal anti-inflammatory drugs (NSAIds) at the early period postinjection. The results suggest that a small amount of IL-1b at the site of periodontal disease can induce Fos-IR in pain-processing neurons.2 The effects of the antagonists and agonists of glutamate receptors on the expression of Fos-IR were examined after tooth pulp stimulation. MK-801, CNQX,AP-3, NMDA,AMPA and phorbol ester were intrathecally administered to rats 10 min prior to stimulation (0.2 ms, 0.6 mA,0.5 Hz, 10 min) ; the effects or each agent on the expression of Fos-IR was studied in the caudalis at 2 h post-stimulation. The results suggest that Ca^<2+> entry through an NMDA receptor is crucial to the induction of c-Fos and to the development of persistent pain.