青藤碱对切口痛模型大鼠的镇痛效应及其中枢神经系统中P物质含量的影响

目的观察青藤碱对切口痛模型大鼠疼痛敏感行为及其脑脊液、脊髓中P物质含量的影响。方法 SD大鼠30只,随机分为模型组（Model）、氯诺昔康组（Lornoxicam,8mg·Kg-1）、青藤碱高剂量组（Sin-H,20mg·Kg-1）和青藤碱低剂量组（Sin-L,10mg·Kg-1）。采用机械痛敏和热痛敏测试,评价大鼠的疼痛行为。放免法检测大鼠脑脊液及脊髓L6-L8中P物质含量。结果切口痛模型大鼠的机械撤足阈值、热刺激痛感缩足时间明显改变。青藤碱高、低剂量和阳性药投与后均显示了明显的镇痛效果,其中青藤碱高剂量组镇痛效应指标优于阳性对照药氯诺昔康;给药各组大鼠脑脊液、脊髓中的P物质含量与模型组相比都下降显著,差异有统计学意义（P〈0.05）,而以青藤碱高剂量组的脑脊液P物质浓度抑制最为明显。结论青藤碱能够减轻切口痛模型大鼠疼痛敏感行为,减少P物质在中枢神经系统的释放,后者可能是青藤碱产生镇痛作用的重要机制之一。

Effects of Sinomenine on Analgesia and Contents of Substance P in Central Nervous System of Incisional Pain Rat Model

Objective To investigate the effects of sinomcnine on analgesia and contents of substance P in central nervous system of incisional pain rat model. Methods Sprague-Dawley rats were randomly divided into model group, lornoxicam group （8mg · Kg^-1）, sinomenine high-dose group （20mg · Kg^-1） and sinomenine low-dose group （ 10mg · Kg^-1 ）. The tests of mechanical allodynia and heat allodynia were used to evaluate the pain be- havior of the rats. The contents of substance P weremeasured by RIA. Results The mechanical and heat pain sensitive behaviors of incisional pain rats changed significantly. After administration, sinomenine high-dose group and lornoxicam group had the effects on analgesia, and sinomenine high-dose was fond of lomoxieam group. Compared with the contents of substance P in cerebrospinal fluid and spinal cord of model group, sino- menine high-dose group, sinomenine low-dose group and lornoxicam group were all decreased significantly （P 〈 0.05 ）. Conclusion Sinomenine can relieve the pain sensitive behavior of ineisional pain rats. Its analgesic effect may be related to inhibiting releasing of substance P in central nervous system.