吗啡与氯诺昔康复合应用对大鼠激光痛阈的影响

Effect of morphine combined with lornoxicam on CO_2 laser pain threshold in rats

目的:研究不同剂量吗啡与氯诺昔康复合应用对大鼠激光痛阈的影响,探讨二者是否具有协同作用。方法:成年雄性SD大鼠42只,随机分为7组:生理盐水对照组(control),吗啡组(M),氯诺昔康组(L),合并给药组ML1、ML2、ML3组。各组大鼠分别于给药前,给药后15、30、60、120min进行痛阈测定,并计算痛阈提高百分率,以比较不同剂量的药效。依金正均法计算Q值,评价吗啡与氯诺昔康之间的相互作用。结果:各组间给药前CO2激光痛阈无显著性差异。给药后15min大鼠痛阈开始增高,30min达到峰值,较高剂量组可持续至给药后120min。计算给药后M、L、ML1组60min时痛阈提高百分率并用金正均法计算Q值,Q=1.18。结论:吗啡与氯诺昔康复合应用,在一定范围内镇痛效应随剂量增加而增大,Q值大于1.15,表明两药药效有一定的协同作用。

Objective： To study the effect of different doses of morphine combined with lomoxicam on CO2 laser pain threshold in rats and whether morphine and lornoxicam have synergistic effects. Methods： Forty-two male SD rats, weighting 200 -250g, were randomly divided into seven groups. Rats in control group received hypodermic injection of 1 mL 0.9% NaC1; rats in group M received hypodermic injection of morphine （4mg/kg） ; rats in group L received hypodermic injection of lomoxicam （4mg/kg） ; rats in groups ML1 , ML2 and ML3 received hypodermic injection of morphine combined with lornoxicam（4mg/kg ＆ 4mg/kg, 2mg/kg ＆ 2mg/kg, lmg/kg ＆ lmg/kg）, respectively. Pain behavior of CO2 laser was assessed at 15, 30, 60 and 120min before and after drug administration. The percentage of pain threshold was calculated. The interaction type was estimated by Q value provided by Jin Zhengjun＇s method. Results： The pain thresholds of rats in all groups except for control group began to increase at about 15min after drug administration and reached their peak at 30min. The effect was maintained till 120min after drug administration in groups M, ML1 and ML2. The pain thresholds of rats in groups ML1, ML2 and ML3 showed a statistical difference, and increased with the increasing dose of drugs. The analgesic effect of morphine combined with lornoxicam was significantly higher than that of morphine or lornoxiam alone. The Q value at 60min after drug administration was calculated, and Q 〉 1.15 indicated that the two drugs had significant synergistic effects. Conclusion： Morphine combined with lornoxicam provides analgesia in a dose-dependent manner. The combination of morphine and lomoxicam has synergistic effects.