摘要
目的 :探讨刺激大鼠海马后脑干镇痛核团 5 HT的变化 ,分析海马在镇痛中的作用机制。方法 :健康成年Wistar大鼠 40只 ,随机分为 4组。A组 :正常对照组 ,不给动物任何处理 ;B组 :疼痛组 ,以大鼠右侧后脚掌注射2 5g/L多聚甲醛 0 4ml作为疼痛模型 ;C组 :谷氨酸钠组 ,将疼痛模型动物经腹腔注射 2 0g/L戊巴比妥钠麻醉后、固定在脑立体定位仪上 ,按GeorgePaxions定位图谱用微玻管将 0 5 μl(1mg/L)L 谷氨酸钠 (L GLU)注射入大鼠右侧海马 ;D组 :生理盐水组 ,同上向疼痛模型动物海马内注射 0 5 μl生理盐水。 4组动物均于 2h后处死 ,常规灌注冰冻切片 ,采用SABC免疫组化和计算机图像分析技术 ,检测中脑导水管周围灰质 (PAG)、中缝大核 (NRM) 5 HT神经元阳性细胞个数及光密度等均值。结果 :疼痛刺激后 ,PAG、NRM内 5 HT水平较正常显著增高 (P <0 0 5 ) ,谷氨酸钠组则较疼痛组进一步增加。结论 :海马兴奋后 ,激活内源性镇痛系统 ,使 5 HT大量释放 ,参与镇痛。
Aim: To study the changes of 5 HT in PAG and NRM in brain stem after stimulation of hippocampus and investigate the mechanism of hippocampal analgesia.Methods:Fourty adult wistar rats(healthy)were randomly divided into 4 groups:a)Normal Group:normal rat without any treatment;b)Pain Group:0 4 ml 2 5 g/L formalin was subcutaneously injected into right hindpaw of rat;c)Sodium Glutamate Group:locating the dorsal hippocampus(P 3 8 mm,L 1 5 mm,Dn 3 0 mm)of the rat after 0.4 ml formalin was injected about 20 min,and 0.5 μl sodium glutamate(1 mg/L) was microinjected into the right hippocampus;d)Normal Saline Group:same treatment as sodium glutamate but microinjected 0.5 μl physiological saline.After 2 h all rats were executed and perfused.Sections were made for SABC immunohistochemistry,then proceeded by computed image analyzer.The number and optic densities of 5 HT positive cells were measured.Results:After pain stimulation,the level of 5 HT in PAG and NRM increased than normal level( P <0 05).After injected sodium glutamate 5 HT positive cells in PAG and NRM obviously increased than that of Pain Group.Conclusion:When neurons of hippocampus become excited the endogenous analgesia system can be activated,which makes 5 HT released Hippocampus participates in analgesia.
出处
《河南医科大学学报》
北大核心
2001年第5期557-559,共3页
Journal of Henan Medical University
基金
河南省自然科学基金资助项目 9940 2 430 0
关键词
海马
5-羟色胺
内源性镇痛系统
大鼠
hippocampus
5-hytroxytryptamine
endogenous analgesia system
