鞘内注射辣椒素对恩氟醚和七氟醚镇痛作用的影响

The effects of intrathecal injecting capsaicin on the analgesia effects of enflurane and sevoflurane

目的 研究瞬时感受器电位香草酸受体1 （transient receptor potential vanilloid 1,TRPV1）,即辣椒素受体,在吸入麻醉药恩氟醚（enflurane,Enf）和七氟醚（sevoflurane,Sev）镇痛效果中的作用. 方法 实验分热板法和扭体法两轮进行,每轮实验昆明小鼠120只,完全随机法按腹腔注射（热板法）或皮下注射（扭体法）不同试剂分为生理盐水组、Enf组、Sev组三大组,建立小鼠注射吸入麻醉药镇痛模型.每大组再根据鞘内注射溶媒或不同剂量辣椒素（2.5、5、10 ng）分为4个亚组,观察鞘内注射不同剂量TRPV1激动剂辣椒素对Enf、Sev镇痛小鼠痛阈的影响. 结果 鞘内注射辣椒素2.5、5、10 ng对清醒小鼠热板法痛阈（pain threshold in hot-plate test,HPPT）和扭体次数的影响差异无统计学意义（P＞0.05）;鞘内注射辣椒素2.5、5、10 ng可减少Enf、Sev镇痛小鼠HPPT（P＜0.05）,增加扭体反应次数[Enf组：（22±7）、（24±5）、（29±6）次比（16±6）次;Sev组：（21±6）、（23±7）、（28±4）次比（13±5）次]（P＜0.05）. 结论 脊髓的TRPV1可能是吸入麻醉药Enf和Sev镇痛作用的重要靶位.

Objective The present research was designed to explore the role of transient receptor potential vanilloid 1 （TRPV1） in analgesia induced by enflurane （Enf） and sevoflurane （Sev）.Methods Two hundred and forty mice were completely randomly divided into intraperitoneally （ip） （hot-plate test） or subcutaneously （SC） （acetic acid-induced writhing test） saline and Enf,Sev groups and each group according to intrathecal injection solvent and capsaicin （2.5,5,10 ng） was divided into four subgroups.After established the mice model of analgesia by intraperitoneal or subcutaneous injection of appropriate doses of Enf or Sev,we injected different doses of capsaicin intrathecally and observed effects on the pain threshold using the hot-plate and acetic acidinduced writhing test.Results The results showed that intrathecal injection of capsaicin （2.5,5,10 ng） did not affect the pain threshold in hot-plate test （HPPT） or the writhing numbers in conscious mice （P〉0.05）.In contrast,capsaicin （2.5,5,10 ng intrathecally） was significantly decreased the HPPT and increased the writhing nubmers[Enf group：（22±7）,（24±5）,（29±6） vs （16±6）,Sev group：（21±6）,（23±7）,（28±4） vs （13±5）] in mice treated with Enf or Sev（P〈0.05）.Conclusions These results suggest that spinal TRPV1 may mediate the analgesic effects of Enf and Sev.