摘要
目的:观察鞘内注射右美托咪定(dexmedetomidine,DEX)对炎症性疼痛大鼠的镇痛作用以及对大鼠脊髓背角P物质(substance P,SP)表达的影响;明确DEX对炎症性疼痛大鼠具有超前镇痛效应。方法:建立福尔马林诱导的炎症性疼痛SD大鼠模型并给予鞘内注射DEX;观察大鼠疼痛行为学变化;免疫组织化学法和免疫印迹法检测大鼠脊髓背角(L4-6)SP阳性表达变化。结果:炎症性疼痛大鼠疼痛行为学评分增加,脊髓背角SP阳性表达上调;给予鞘内注射DEX可降低炎症性疼痛大鼠疼痛行为学评分以及脊髓背角SP阳性的表达(P均<0.001);鞘内预注射DEX大鼠的疼痛行为学评分和脊髓背角SP表达低于DEX后处理组(P均<0.001)。结论:鞘内注射DEX通过抑制炎症性疼痛大鼠脊髓背角SP表达产生镇痛作用,该作用具有超前镇痛效应。
Objective： To observe the analgesic effect of the intrathecal injection of the dexmedetomidine（ DEX） on acute inflammatory rats induced by subcutaneous injection of the formalin,and the expression alterations of the substance P（ SP） in the spinal dorsal horn on rats. The study was also designed to test the preemptive analgesic effect of DEX on the inflammatory pain rats. Methods：The formaline-induced inflammatory pain model of SD rats was established by subcutaneous injection of formalin into the plantar surface of the left hind paw of rats. The DEX was intrathecally injected and the pain-related behaviors were studied. The expression changes of substance P（ SP） in the spinal dorsal horn（ L4-6） were detected by using the immunohistochemistry and Western blot methods. Results： The cumulative pain scores were increased and the SP-positive expression in the dorsal horn was up-regulated after intraplantar injection of formalin. The intrathecal injection of DEX decreased the cumulative pain scores and inhibited the SP-positive expression.Additionally,the analgeic effect of the pre-injection DEX was stronger than the post-injection. Conclusion： Intrathecal injection of the DEX can attenuate the inflammatory pain in rats through inhibiting the expression of SP expression in the dorsal horn of spinal cord,and the administration of DEX has a preemptive analgesic effect at the spinal level in formalin-induced inflammatory pain.
出处
《川北医学院学报》
CAS
2017年第1期5-9,共5页
Journal of North Sichuan Medical College
基金
贵州省科学技术基金项目[黔科合J字LKZ(2011)21号]
关键词
右美托咪定
炎症性疼痛
超前镇痛
P物质
Dexmedetomidine
Inflammatory pain
Preemptive analgesia
Substance P
