中文摘要：

目的观察颅内注射局麻药罗哌卡因对大鼠骨癌痛阈的影响,探讨骨癌痛的机制。方法建立大鼠骨癌痛模型后,立体定位引导下在大鼠脑干延髓头端腹内侧区（rostral ventromedial medulla,RVM）置管,通过von Frey filaments,Pin Prick test,Ambulatory pain三种方法检测骨癌痛大鼠在RVM内给予罗哌卡因后痛阈的改变。结果构建骨癌痛模型后,大鼠痛阈呈现进行性下降趋势。颅内微注射0.5%罗哌卡因后,骨癌痛大鼠的机械性痛觉超敏,机械性痛觉过敏,移动触诱发痛3种不同性质的疼痛痛阈均显著升高,痛觉行为显著改善。结论RVM区内注射局麻药罗哌卡因可以起到显著的镇痛效果,提示脑干RVM区在骨癌痛的形成和维持中起重要作用。

英文摘要：

Objective To study the analgesic effects of local anesthetic ropivacaine by intracerebral injection in a rat model of bone cancer pain.Methods After the model of bone cancer pain was made,intracerebral guide cannula were implanted into the RVM（rostral ventromedial medulla）.Von Frey filaments,Pin Prick test,Ambulatory pain were used to measure the pain thresholds before and after ropivacaine microinjection.Results Pain thresholds were significantly decreased in rats with bone cancer pain.After intra RVM administration of 0.5% ropivacaine,mechanical allodynia,mechanical hyperalgesia and ambulatory pain were attenuated and the pain behavior were significantly reversed.Conclusion Intra RVM administration of ropivacaine produces remarkable analgesic effects in a rat model of bone cancer pain.Thus,the RVM is critical for the development and maintenance of bone cancer pain.