小剂量曲马多与右美托咪定对神经病理性疼痛大鼠的抗抑郁效果

THE ANTIDEPRESSANT EFFECT OF TRAMADOL AND DEXMEDETOMIDINE IN RATS WITH NEUROPATHIC PAIN

目的：本文旨在探讨联合应用小剂量曲马多与右美托咪定对神经病理性疼痛模型大鼠的抗抑郁效果.方法：健康成年Wistar雄性大鼠56只,体重200～300 g,将慢性神经病理性疼痛模型组大鼠（n=32）和假手术组大鼠（n=24）分别随机分为4组.按以下剂量给药：曲马多20 mg/kg（OT和ST组）、右美托咪定20 μg/kg（OD和SD组）、曲马多5 mg/kg＋右美托咪定5 μg/kg（OT＋D和ST＋D组）、生理盐水组（Oc和Sc组）.术后待大鼠恢复14天,于每日清晨8：00给予腹腔注射相应药物,连续14天.并于手术前3天、术后14天及给药后14天采用Von Frey测定大鼠坐骨神经结扎侧（本实验右侧）机械痛阈（Mechanical Withdrawal Threshold,MWT）,强迫游泳实验（Forced Swimming Test,FST）大鼠的上窜时间、不动时间以及测定大鼠血清皮质醇水平.结果：手术组大鼠术后14天,MWT值明显降低,FST中不动时间明显延长.OT组和OT＋D组大鼠给药后MWT值上调,FST中不动时间明显缩短.OD组大鼠给药后MWT与给药前相比明显增加,而FST中不动时间没有明显改变.OT＋D组与OT、OD组相比FST不动时间明显缩短（P＜0.05）.假手术组各给药组MWT和FST中不动时间在给药前后没有明显差异.OT＋D组与OT、OD组相比皮质醇水平增高.结论：腹腔联合应用小剂量曲马多与右美托咪定对神经病理性疼痛模型大鼠抗抑郁效果比单独应用曲马多或右美托咪定效果好.

Objective：The aim of this study was to evaluate the antidepressant effect of the comitant use of tramadol （TRA） and dexmedetomidine （DEX） in neuropathic pain rats.Methods：Chronic constrictive injury of the sciatic nerve and sham operation were performed on healthy,male,Wistar rats,weighing 200～300 g.The chronic neuropathic pain model rats and sham-operated were randomly divided into four groups respectively：TRA （OT,ST）,DEX （OD,SD）,TRA ＋ DEX （OT ＋ D,ST ＋ D）,Saline group （Oc,Sc）.After 14 days＇ recovery,saline,TRA （20 mg/kg/day）,DEX （20 μg/kg/day） or TRA （5 mg/kg/day） ＋ DEX （5 μg/kg/day） were administrated intraperitoneally at 8：00 a.m.for 14 days.Mechanical Withdrawal Threshold （MWT） and Forced Swimming Test （FST） were detected in three days before surgery,14 days after surgery and 14 days after administration respectively.The serum cortisol level was detected 14 days after administration.Results：The MWT of the model rats was significantly decreased compared with the sham group 14 days after the operation,and the immobility time in FST was also significantly prolonged.After 14 days drug administration,MWT of the OT and OT ＋ D group were increased,and the immobility time in FST was shorter than those before drug administration.For the OD group,the MWT increased significantly than before,while the FST immobility time did not change obviously.When compared to OD and OT,the FST immobility time of OT ＋ D was significantly shorter （P ＜ 0.05）.There was no significant difference on MWT and the FST immobility time before administration and after in sham group.The cortisol levels of OT＋D group was higher than OT and OD.Conclusion：The antidepressant effect of small doses comitant use of tramadol and dexmedetomidine on rats of neuropathic pain was better than that was used alone.