白介素-2参与云芝糖肽镇痛作用的研究

Studies on the Analgesic Effect of Polysaccharopeptide and Its Mechanism

[目的]研究云芝糖肽(polysaccharopeptide,PSP)的镇痛作用并探讨其镇痛机制。[方法]60只SD大鼠,随机分为5组,即正常对照组、不同剂量PSP组和杜冷丁阳性对照组。PSP连续给药6d,用电刺激鼠尾-嘶叫法测定痛阈,观察PSP对痛阈的影响。同时测定PSP对下丘脑内侧基底部(MBH)白介素-2(IL-2)和白介素-2受体(IL-2R)表达的影响。[结果]大鼠经PSP治疗后,与正常组比,其痛阈升高,且有明显的量效关系。PSP能增加大鼠MBH区域IL-2免疫反应阳性细胞的数量,减少IL-2R阳性颗粒的分布。[结论]PSP有中枢性镇痛作用,其镇痛作用靶点可能位于下丘脑内侧基底部。机制可能与PSP刺激T细胞分泌IL-2,IL-2进入脑内并与MBH中的IL-2受体结合有关。

[Objective] The study focus on the analgesic effect of polysaccharopeptide（PSP）and discuss the mechanism of this analge sia. [Methods] A total of 80 rats were divided randomly into high dose of psp,medium dose of psp, low doses of psp, positive con- trol group, negative control group. After intragastric （ig） administration of different （high, medium and low）doses of PSP for 6 days,The tail stimulation-vocalization test was used to observe the analgesic effect of PSP. The IL 2 and II. 2R expression in medio basal hypothalamus （MBH） was studied immunohistochemically. [Results] After intragastric （ig） administration of PSP for 6 days, the pain threshold was increased significantly and a dose-effect relationship was observed. After PSP administration the IL-2 expression in MBH was increased, while the IL-2R expression in MBH was decreased. [Conclusion] PSP has a definite analgesic effect and its analgesic site is in the MBH. The analgesia might be produced by the binding with the IL-2R in MBH by IL-2 secreted by T cells after PSP was injected into the brain.