延髓头端腹内侧核GABAA受体在异丙酚致大鼠痛觉过敏中的作用  

Role of GABAA receptor in hyperalgesia induced by propofol injected into rostral ventromedial medulla in rats

作　　者：王擒云[1] 杨建平[1] 张慧娟[1] 戴体俊[2] 

机构地区：[1]苏州大学附属第一医院麻醉科,215006 [2]徐州医学院麻醉学院

出　　处：《中华麻醉学杂志》2010年第1期40-43,共4页Chinese Journal of Anesthesiology

基　　金：国家自然科学基金（30872442）;苏州大学附属第一医院青年创新项目（VQN02）

摘　　要：目的探讨延髓头端腹内侧核γ-氨基丁酸A亚型（GABAA）受体在异丙酚致大鼠痛觉过敏中的作用。方法清洁级SD大鼠64只，雌雄不拘，月龄2～3月，体重250。300g，随机分为4组（n=16）：溶媒对照组（C组）、异丙酚组（P组）、荷包牡丹碱组（B组）及荷包牡丹碱＋异丙酚组（BP组）。参照脑立体定位图谱定位大鼠延髓头端腹内侧核，C组注射人工脑脊液（荷包牡丹碱溶媒）0．4μl，5min后注射二甲基亚砜（异丙酚溶媒）0．4μl，P组注射异丙酚0．4μl（4μg），B组注射荷包牡丹碱0．4μl（10ng），BP组注射荷包牡丹碱0．4μl（10ng），5min后注射异丙酚0．4出（4μg），各药物均在308内注射完毕，30s后拔针。各取8只大鼠分别进行热板实验和福尔马林实验，记录热痛阈、福尔马林疼痛评分及其第1时相和第2时相累计疼痛评分。结果热板实验中，P组热痛阈低于C组，BP组给药后20rain时热痛阈明显高于P组（P〈0．05或0．01），其余时点差异无统计学意义（P〉0．05）。福尔马林实验中，P组福尔马林疼痛评分高于C组，BP组各时点福尔马林疼痛评分和第1、2时相累计疼痛评分均明显低于P组（P〈0．05或0．01）。结论延髓头端腹内侧核GABA。受体部分介导了异丙酚致大鼠痛觉过敏作用。Objective To investigate the effects of propofol injected into rostral ventromedial medulla （RVM） on nociceptive responses and examine whether GABAA resceptor is involved in the mechanism. Methods Sixty-four pathogen free SD rats of both sexes aged 2-3 months weighing 250-300 g were randomly divided into 4 groups （ n = 16 each） ： group T control （group C） ; group 11 propofol （group P） ; group m bicucuUine （group B） and group IV B ＋ P （group BP）. The animals were anesthetized with intraperitoneal 1% pentobarbital 50 mg/kg. Their heads were fixed with stereotactic apparatus. An traear was inserted into RVM for microinjection of propofol and/or bicuculline. The noxious responses were evaluated by hot plate test （response latency was measured） and formalin test （intraplantar injection of 2.0% formalin 100 μl）. Pain was scored （0 = no pain, 3 = severe pain）. Results Both hot plate test and formalin test showed that hyperalgesia was induced by microinjection of propofol into RVM. In hot plate test hyperalgesia induced by injection of propofol （4 μg/0.4 μl） into RVM was antagonized at 20 rain after microinjection of bicuculline （10 ng/0.4 μl） into RVM. In formalin test pain scores were significantly lower at 1, 5,10,20,30,40,50 and 60 min after intraplantar formalin injection in group BP than in group P. Conclusion GABAA receptor in RVM partially mediates propofol-indueed hyperalgesia.

关 键 词：二异丙酚 延髓 受体 GABA-A 痛觉过敏 

分 类 号：R614[医药卫生—麻醉学]