外周炎症性疼痛诱导下丘脑弓状核c-fos表达及其机制  

Peripheral Inflammatory Pain Induces c-fos Expression in Hypothalamic Arcuate Nucleus and Its Mechanism

作　　者：李玮[1] 龚珊[1] 虞献民 蒋星红[1] 

机构地区：[1]苏州大学医学部基础医学与生命科学学院神经生物与医学心理学系衰老与神经疾病实验室,江苏苏州215123 [2]美国佛罗里达州立大学医学院生物医学系

出　　处：《苏州大学学报（医学版）》2011年第2期217-220,共4页Suzhou University Journal of Medical Science

基　　金：江苏省自然科学基金资助项目(L2134913);复旦大学医学神经生物学国家重点实验室开放课题资助项目(09-09)

摘　　要：目的观察下丘脑弓状核(ARC)神经元在炎症性痛觉过敏中的激活状态,分析NMDA受体在ARC神经元活动与痛觉过敏中的作用。方法用完全弗氏佐剂建立大鼠炎症性痛觉过敏模型,用辐射热-缩腿法测定痛阈,用c-fos检测神经元激活状态,用体视学无偏差测量系统计数免疫阳性细胞,用MK801观测NMDA受体的作用。结果佐剂组的痛阈均有明显下降(P<0.05),ARC中Fos蛋白阳性细胞计数明显上调(P<0.05);在侧脑室微量注射MK801后痛阈可恢复至正常水平,ARC中Fos蛋白阳性细胞计数回落接近正常水平。生理盐水组在这两方面都无明显变化。结论 ARC神经元的激活对炎症性痛觉过敏的产生和维持有重要作用,该作用主要通过NMDA受体介导。中枢敏感化也可发生在脊髓以上的高位痛觉调节中枢。Objective To study the activation of hypothalamic arcuate nucleus neurons in inflammatory hyperagesia and the role of NMDA receptor.Methods The inflammatory hyperalgesia model was induced by complete Freund＇s adjuvant in rats.Pain threshold was measured by radiant heat-withdrawal method.The neuronal activation in arcuate nucleus was evaluated by c-fos expression.The immunoreactive positive cells were counted using unbiased stereological method.The role of NMDA receptor was tested by using its antagonist MK-801.Results 7,14 and 21 days after model made the pain threshold decreased significantly（P0.05）,at the same time the number of Fos-positive neurons in arcuate nucleus was up-regulated significantly（P0.05）.Intracerebroventricular microinjection of NMDA receptor antagonist MK-801 could reverse the decrease of pain threshold,as well as the up-regulation of Fos-positive neurons in arcuate nucleus.No significant changes were observed in pain threshold as well as in number of Fos-positive cells in the saline control group.Conclusion Neuronal activation in arcuate nucleus plays an important role in the production and maintenance of inflammatory hyperalgesia.This activation is mediated by NMDA receptor.Central sensitization may be produced as well in the supraspinal higher pain-modulatory centers.

关 键 词：下丘脑弓状核 完全弗氏佐剂模型 痛觉过敏 FOS蛋白 NMDA受体 

分 类 号：R338.3[医药卫生—人体生理学]