丘脑中央下核内给予吗啡对福尔马林诱发炎性持续痛的抑制效应

Inhibitory Effect of Morphine Microinjection into Thalamic Nucleus Submedius on Formalin-induced Inflammatory Hyperalgesia in Rat

目的:研究丘脑中央下核(Sm)内给予吗啡对福尔马林诱发大鼠炎性持续痛的效应。方法:采用福尔马林(体积分数5%,50μL)足底注射刺激,核团内微量注射药物,用自动检测系统记录大鼠的伤害性行为。结果:福尔马林诱发的晚时相反应(炎性持续痛)可被单侧Sm内供给吗啡(5.0μg)明显抑制,阿片受体拮抗剂(纳络酮,1.0μg)可完全翻转吗啡诱发的抑制效应。结论:Sm内给予吗啡对福尔马林诱发的炎性持续痛产生明确的抗伤害效应。

Objective： To investigate the possible effect of morphine microinjection into thalamic nucleus submedius （Sm）on formalin-induced inflammatory hyperalgesia in rat. Methods： Formalin（5%, 50 μL）was subcutaneously injected into the rat hindpaw and drugs were microinjected into the submedius, the formalin-evoked nociceptive behaviors（agitation） were quantified via automated detection system. Results： Morphine（5.0 μg） microinjected unilaterally into Sm depressed rat agitation, and this could be blocked by administration of opiate receptor antagonist naloxone（ 1.0 μg）. Conclusion： The local application of morphine into Sm produces an inhibitory effect on formalin-induced inflammatory hyperalgesia.