鞘内给予不同剂量吗啡对神经源性痛大鼠机械及冷刺激痛敏症状的剂量依赖性镇痛作用  

Analgesic effects of different dosage of morphine given into sheath on allodynia-like symptoms due to mechanical and cold stimulation in rats with neuropathic pain in a dose-dependent manner

作　　者：郭跃先[1] 王秀丽[1] 王鹏程[1] 杨淑红[1] 张金华[1] 

机构地区：[1]河北医科大学第三医院外科,河北省石家庄市050051

出　　处：《中国临床康复》2005年第25期114-116,共3页Chinese Journal of Clinical Rehabilitation

基　　金：河北省科技攻关课题(042461600D)~~

摘　　要：目的:探讨鞘内注射吗啡对慢性神经源性痛大鼠机械和冷刺激痛敏症状的镇痛作用及其剂量依赖关系。方法:实验于2005-10/12在河北医科大学第三医院动物中心实验室完成。取35只SD雄性大鼠制备成一侧脊神经(L5,L6)结扎模型,1周后当机械缩腿阈值达1～4g并出现痛敏症状后,将其随机分为5组(n=7):生理盐水组经鞘内一次性注射生理盐水10μL;吗啡0.1,0.5,1,5μg组经鞘内分别一次性注射吗啡0.1,0.5,1,5μg,均溶于10μL生理盐水中。于给药前及给药后15,30,60,120和180min分别测量大鼠神经损伤侧的机械缩腿阈值犤正常大鼠基础缩腿阈值为(25.16±1.14)g犦和5℃的冷板5min内冷刺激后的抬足次数。结果:所有35只大鼠均进入结果分析。①各组大鼠机械缩腿阈值:脊神经结扎后1周时为(2.76±1.01)g。吗啡0.5,1,5μg组均高于生理盐水组,作用高峰时间为给药后的30min犤(6.13±3.67),(14.27±2.78),(25.13±7.44),(4.04±1.12)g,P<0.01犦,而吗啡1,5μg组升高更为显著(P<0.01),持续时间达180min。②各组大鼠冷刺激后抬足次数:经5min内冷刺激吗啡0.1,0.5,1,5μg组均减少,作用高峰时间为给药后的30min,分别为(24.14±6.77),(14.00±9.79),(6.17±4.31),(1.33±0.33)次,其中吗啡0.5,1,5μg组显著低于生理盐水组犤(29.83±7.44)次,P<0.05犦,而吗啡1,5μg组降低更为显著(P<0.01),持续时间达180min。结论:结果证实在L5和L6脊神经结扎模型基础上诱导产生慢性神经源性痛,鞘内注射吗啡(0.1～5μg)对慢性神经痛大鼠机械和温度刺激引起的痛敏症状均具有明显的镇痛作用,其中吗啡1～5μg的镇痛作用可持续180min,提示吗啡对神经源性痛具有剂量依赖性的镇痛作用。AIM： To observe the analgesic effect and its dosage dependence relation of the injection of morphine on allodynia-like symptom induced by mechanical and cold stimulation in rats with chronic neuropathic pain. METHODS： The experiment was carried out in Animal Center Laboratory of Third Hospital of Hebei Medical University from October to December 2005. Thirty-five male SD rats were created the model of unilateral spinal nerve ligation （SNL） （L5, L6）. One week later when the liminal value of mechanical contractive leg reached 1-4 g and pain sensitive symptom appeared, then they were divided randomly into 5 groups （n=7）： The rats in saline group were injected with 10 μL saline through sheath once; The rats in morphine 0.1, 0.5, 1 and 5 μg group were injected with morphine 0.1, 0.5, 1 and 5 μg through sheath once respectively, all siddolved in 10 μL saline. The liminal value of mechanical contractive leg in neuropathic damage side 15, 30, 60, 120 and 180 minutes before and after injecting with drug respectively [The liminal value of mechanical contractive leg of normal rats was （25.16±1.14） g] with 5 ℃ cold board the number of times of rising legs after 5 minutes cold stimulation were measured. RESULTS： Totally 35 rats were involved in the analysis of results. ① the liminal value of mechanical contractive leg of rats in each group： At one week after SNL it was （2.76±1.01） g. It was higher in morphine 0.5, 1 and 5 μg group than that in saline group, and the peak time was 30 minutes after administration [（6.13±3.67）, （14.27±9.78）, （25.13±7.44）, （4.04±1.12） g, （P 〈 0.01）]. It significantly increased in morphine 1 and 5 μg group （P 〈 0.01 ）lasing for 180 minutes. ② The number of times of rising legs after cold stimulation in rats in every group： It reduced in morphia 0.1, 0.5, 1 and 5 μg group after 5 minutes cold stimulation, and peak time was 30 minutes after administration （24.14±6.77）, （ 14.00±9.79）, （6.17±4.31 ）, （1.33±0

关 键 词：疼痛 吗啡 神经系统/损伤 痛觉过敏 

分 类 号：R745[医药卫生—神经病学与精神病学]