顺铂对切口痛大鼠吗啡镇痛效应的影响

Effect of cisplatin on analgesia with morphine in rats with incisional pain

目的评价顺铂对切口痛大鼠吗啡镇痛效应的影响。方法成年雄性sD大鼠42只，体重180．220g，采用随机数字表法，将大鼠分成6组（n=7）：生理盐水组（C组）、生理盐水＋P-糖蛋白抑制剂LY335979组（CL组）、生理盐水＋吗啡（CM组）、顺铂组（S组）、顺铂＋吗啡组（SM组）和顺铂＋吗啡＋LY335979组（SML组）。s组、SM组和SML组腹腔注射顺铂2mg／kg，1次／2d，共5次；C组、CL组和CM组腹腔注射等容量生理盐水。给药结束后2d时，建立大鼠切口痛模型。切口痛模型建立后10min，C组和S组皮下注射生理盐水2ml；CL组尾静脉注射LY33597920mg／kg，皮下注射生理盐水2ml；CM组和SM组皮下注射吗啡2mg／kg；SML组尾静脉注射LY33597920mg／kg，皮下注射吗啡2mg／kg。采用累计痛评分法评价镇痛效应。结果与C组比较，CM组累计痛评分降低（P〈0．05），CL组和S组累计痛评分差异无统计学意义（P〉0．05）；与CM组比较，SM组累计痛评分升高（P〈0．05），SML组累计痛评分差异无统计学意义（P〉O．05）；与sM组比较，SML组累计痛评分降低（P〈0．05）。结论顺铂可通过增强血脑屏障P-糖蛋白的功能减弱吗啡对切口痛大鼠的镇痛效应。

Objective To evaluate the effect of cisplatin on analgesia with morphine in rats with incisional pain. Methods Forty-two adult male Spragne-Dawley rats, weighing 180-220 g, were randomly divided into 6 groups （n = 7 each ） using a random number table： normal saline group （group C ）, normal saline ＋ P- glycoprotein inhibitor LY335979 group （group CL）, normal saline ＋ morphine group （group CM）, eisplatin group （group S）, eisplatin ＋ morphine group （group SM） and cisplatin ＋ morphine ＋ LY335979 group （group SML）. Cisplatin 2 mg/kg was injected intraperitoneally once every two days for 5 times in S, SM and SML groups, while the equal volume of normal saline was injected intraperitoneally in C, CL and CM groups. At 2 days after the end of administration, the ineisional pain models were established. At 10 min after establishing the model, normal saline 2 ml was injected subcutaneously in C and S groups; LY335979 20 mg/kg was injected via the caudal vein and normal saline 2 ml was injected subcutaneously in group CL; morphine 2 mg/kg was injected subcutaneously in CM and SM groups; LY335979 20 mg/kg was injected via the caudal vein and morphine 2 mg/kg was injected subcutaneously in group SML. Cumulative pain score was used to evaluate analgesia. Results Compared with group C, cumulative pain scores were significantly decreased in group CM, and no significant change was found in cumulative pain scores in CL and S groups. Compared with group CM, cumulative pain scores were significantly increased in group SM, and no significant change was found in cumulative pain scores in group SML. Cumulative pain scores were significantly lower in group SML than in group SM. Conclusion Cisplatin can weaken analgesia induced by morphine in rats with incisional pain through enhancing P-glycoprotein function in the blood-brain barrier.