AMPA对吸入麻醉药催眠、镇痛作用的影响

Effcets of AMPA on the hypnotic and analgesic effects of inhalation anesthetics

目的探讨AMPA(α-amino-3-hydroxy-5-methyl-4-isox-azolepropionic acid,AMPA)对吸入麻醉药恩氟烷、异氟烷、七氟烷催眠、镇痛作用的影响。方法建立小鼠腹腔注射吸入麻醉药催眠、镇痛模型,在催眠和热板法实验中分别观察侧脑室(intracerebroventricular,icv)或鞘内(intrathecal,it)注射不同剂量的AMPA对小鼠睡眠时间(sleep time,ST)和热板法痛阈值(pain threshold in hot-plate test,HPPT)的影响。结果催眠实验中,AMPA50、75、100ng组的ST与aCSF组相比,差异无统计学意义(P>0.05)。镇痛实验中,aCSF及AMPA0.25、0.5、1.0ng it对正常对照组小鼠的HPPT均无影响(P>0.05)。AMPA0.25、0.5、1.0ng it剂量依赖性地降低吸入麻醉药镇痛小鼠的HPPT(P<0.05或P<0.01)。结论脑内的AMPA受体与吸入麻醉药恩氟烷、异氟烷、七氟烷催眠作用的关系不大,脊髓的AMPA受体参与了吸入麻醉药恩氟烷、异氟烷、七氟烷的镇痛作用。

Aim To investigate the relationship between α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid（AMPA） receptors and the hypnotic and analgesic effects of enflurane, isoflurane and sevoflurane. Methods After having established the mice model of hypnosis and analgesia by intraperitoneally （ip） injected appropriate doses of sevoflurane, different doses enflurane, isoflurane and of AMPA were we intrace-rebroventricularly（ icv ） or intrathecally （it） injected, then the effects on the sleep time （ST） were observed by using hypnosis test and pain threshold was observed by using hot-plate test. Results In hypnosis test, AMPA （50, 75 and 100 ng icy） had no distinctive effects on the sleep time of the mice treated with inhalation anesthetics （ P 〉 0. 05 ）. In hot-plate test, AMPA （0. 25, 0. 5 and 1.0 ng it） exhibited no effects on the pain threshold in hot-plate test （HPPT）in normal control group（ P 〉 0. 05 ）. In the 3 ip inhalation anesthetics groups, AMPA （0. 25, 0. 5 and 1.0 ng it） significantly and dose dependently decreased the HPPT（ P 〈 0.05 ,P 〈0. 01 ） compared with the aCSF groups. Conchusion Cerebral AMPA receptors do not play an important role in the hypnotic effects of enflurane, isoflurane and sevoflurane while spinal AMPA receptors are involved in the analgesic effects of the 3 inhalation anesthetics.