中文摘要：

目的：观察鞘内泵入不同剂量的曲马多对甲醛炎性疼痛大鼠免疫功能的影响。方法：将32只成年雄性SD大鼠随机分为生理盐水组（NS组）和曲马多组（T组）,其中T组分为50μg/h（T1）,25μg/h（T2）和12.5μg/h（T3）3种剂量组,每组8只。采用改良Yaksh法进行鞘内置管,Alzet泵持续泵入曲马多或生理盐水。复制甲醛炎性疼痛模型,7 d后采用疼痛加权评分（PIS）评价曲马多的镇痛效应;分离脾脏单个核细胞进行原代培养,检测脾脏T淋巴细胞增殖水平、NK细胞活性;流式细胞仪检测脾脏T淋巴细胞亚群和NK细胞表型变化。结果：与NS组比较,T1,T2,T3组在甲醛炎性疼痛第一时相和第二时相的PIS差异有统计学意义（P〈0.01）,且有量效关系,但3组间比较差异无统计学意义（P〉0.05）。与NS组比较,T1组降低T淋巴细胞增殖水平（P〈0.05）,T2和T3组T淋巴细胞增殖水平无统计学意义（P〉0.05）;T1,T2,T3组NK细胞活性均无统计学意义（P〉0.05）;T1组CD3^＋,CD3^＋CD4^＋数量及百分率降低,CD4^＋/CD8^＋降低（P〈0.01）,而T2和T3组则没有变化（P〉0.05）。结论：鞘内泵入较大镇痛剂量的曲马多（50μg/h）降低大鼠T淋巴细胞增殖转化水平,改变T淋巴细胞亚群表型,对NK细胞活性和表型没有影响;一般镇痛剂量曲马多（25μg/h和12.5μg/h）对机体免疫功能没有影响。

英文摘要：

Objective To evaluate the effect of intrathecal pumping tramadol on cell-mediated immunity in rats with formalin inflammatory pain. Methods Thirty-two Sprague-Dawley adult male rats weighting 250 - 300 g were randomly divided into 4 groups （ n = 8 in each group ） ： Saline group （NS） and 3 tramadol groups （T1, T2, and T3 ）. The rats were anesthetized with intraperitoneal chloral hydrate （300 -350）mg/kg. Microspinal catheter was inserted into the subarachnoid space at the lumber region according to modified Yaksh techniques. In the tramadol groups, after 5 days tramadol was continuously infused through the spinal catheter at 50 （T1） ,25 （T2）, and 12.5 μg/h （T3） for 7 days. In the NS group normal saline was continuously infused instead of tramadol. On Day 7 formalin （5 % , 50 μL ） was injected into the plantar surface of the left hindpaw. The number of flinches, lickings and total time of licking was recorded for 60 min. Pain intensity scoring （ PIS ） （ 0 - 3 ; 0 = no pain, 3 = severe pain ） was used to assess the antinociceptive effect of intrathecal tramadol. The rats were killed after the evaluation of pain intensity. Body weight and spleen weight were measured and spleen index （spleen weight/body weight ） was calculated. T-lymphocyte function was evaluated based on Concanavalin-A （ConA） induced splenocyte proliferation. A modified lactic acid dehydrogenase （LDH） release assay was done to assess the NK cell activity. Phenotypic expressions of cell surface markers of T lymphocyte subsets （ CD3 ^＋ , CD3 ^＋CD4^＋ , CD3^＋ CD8 ^＋ , and CD4^＋/ CD8^＋ ） and NK cell（ CD161 ^＋ ） in the spleen were analyzed by flow cytometry. Results The PIS scores were significantly lower in the T1, T2, and T3 groups than those in the NS group. The spleen index and splenocyte proliferation induced by ConA were significantly suppressed in the T1 group, and the phenotypes of T lymphocyte subsets were significantly changed, but no significant difference was found i