鞘内注射士的宁对吸入麻醉药镇痛作用的影响

EFFECTS OF INTRATHECAL STRYCHNINE ON THE ANALGESIC EFFECTS OF INHALATION ANESTHETICS

目的:探讨士的宁敏感的甘氨酸受体(strychnine-sensitive glycine receptor,GlyR)与吸入麻醉药异氟烷、恩氟烷、七氟烷、乙醚镇痛作用的关系。方法:小鼠腹腔注射(i.p.)吸入麻醉药,以甩尾法和福尔马林法观察鞘内注射(i.t.)士的宁(strychnine,Stry)对吸入麻醉药镇痛作用的影响。结果:在甩尾实验中,Stry0.1μgi.t.能降低乙醚镇痛小鼠的甩尾潜伏期(tail flick latency,TFL)(P<0.05),但对异氟烷、恩氟烷、七氟烷镇痛小鼠的TFL无明显影响(P>0.05)。Stry0.2,0.4μg则使四种吸入麻醉药镇痛小鼠的TFL降低(P<0.05)。福尔马林实验中,腹腔注射吸入麻醉药能产生明显的镇痛作用,但Stry(0.1,0.2,0.4μg)i.t.对上述4种麻醉药的镇痛作用均无明显影响。结论:脊髓GlyR可能是吸入麻醉药抗热刺激伤害的重要靶位,但不影响吸入麻醉药对化学刺激的镇痛作用。

To investigate the relationship between strychnine-sensitive glycine receptor（GlyR） and the analgesic effects of aether, enflurane, isoflurane and sevoflurane. Methods： The mice model of analgesia was established by intraperitoneally injecting （i, p. ） appropriate doses of aether, enflurane, isoflurane or sevoflurane, different doses of strychnine （Stry） were intrathecally （ i. t. ） injected and then the effects on the pain threshold of the mice treated with inhalation anesthetics were obsered using tailwithdrawal test and formalin test. Results： In tail-withdrawal test, the increase of tail flick latency（TFL） induced by four inhalation anesthetics was abolished by strychnine （i. t. ）. In formalin test, inhalation anesthetics （ i. p. ） significantly increased the pain threshold of mice, but Stry （0.1,0.2,0.4 μg） did not affect the pain threshold of mice treated with four inhalation anesthetics. Conclusion： Spinal GlyR mediates the analgesic effects of aether, enflurane, isoflurane, sevoflurane in tail-withdrawal test but not in formalin test,