大鼠硬膜外间隙应用辣椒素镇痛的实验研究  

EXPERIMENTAL STUDY ON ANALGESIC EFFECTS OF EPIDURAL CAPSAICIN

作　　者：佟世义[1] 焦岿然[1] 廖旭[1] 薛富善[1] 

机构地区：[1]中国医学科学院中国协和医科大学整形外科医院麻醉科,北京100041

出　　处：《中国疼痛医学杂志》2004年第1期37-41,共5页Chinese Journal of Pain Medicine

摘　　要：目的 :通过行为学、免疫组织化学和神经电生理学方法观察正常大鼠硬膜外间隙注射辣椒素的镇痛效果 ,并探讨利多卡因消除辣椒素不良反应的可行性。方法 :将正常大鼠 71只 ,随机分为 5组 ,分别于硬膜外间隙置管注射 (0 .1%、0 .2 %、0 .4 % )辣椒素、0 .2 %辣椒素 +利多卡因 ,和生理盐水 +溶媒 (简称NC0 .1组、NC0 .2组、NC0 .4组、LC0 .2组和NT组 ) ,实验采用热辐射仪测定大鼠的热痛阈 ,并观察其不良反应的发生率和痛阈恢复情况。另取硬膜外间隙置管大鼠 6 0只 ,平均分为NC0 .1组、NC0 .2组和LC0 .2组 ,并用正常大鼠 2 0只作为对照组 ,分别于硬膜外间隙注药后 30min和第 5天观察脊髓背角CGRP LI的分布变化 ,并计算其阳性面积。结果 :随着辣椒素浓度的增大 ,其镇痛强度和作用时间逐渐延长 ,不良反应的发生率也随之增高 ;利多卡因可完全消除辣椒素引起的呼吸麻痹和神经刺激性疼痛 ,对痛觉超敏亦具有一定的抑制作用。在硬膜外间隙注射辣椒素后30min和第 5天 ,NC0 .1组脊髓背角的CGRP LI的分布和呈色无明显改变 ;NC0 .2组的CGRP LI呈色浅 ,阳性面积下降 (P〈0 .0 5 ) ;LC0 .2组于 30min时CGRP LI的分布与正常并无明显差别 ,但第 5天时的阳性面积明显下降 ;第 5天时NC0 .2组和LC0 .2组背角CRGP阳性面积间无显?Objective:To evaluate the analgesic effects of epidural capsaicin with behavioral,immunocytochemical and electrophysiological methods, and to determine whether lidocaine might suppress the side-effect of epidural capsaicin. Methods:71 healthy rats were randomly divided into five groups. 0.1%,0.2% and 0.4% capsaicin,0.2% capsaicin+2% lidocaine,and mixture of vehicle and saline were injected into the epidural space of the rats and named as Group NC0.1、Group NC0.2、Group NC0.4、Group LC0.2 and Group NT,respectively. A radio-thermostat was used to measure the heat pain threshold with tail-flick test. 60 rats with epidural catheter were randomly divided into three groups (Group NC0.1,Group NC0.2 and Group LC0.2),and 20 healthy normal rats were used as controls. Following the epidural injection of corresponding reagent,the changes of CGRP-LI in spinal dorsal horn were observed with microscope and determined the positive area in 30 min and on the 5th day,respectively. Results:The analgesic effects was significantly enhanced and prolonged with increasing concentrations of capsaicin,but the rate of side-effects was also elevated. Lidocaine could completely eliminate respiratory paralysis and nerve-stimulating pain, and reduce allodynia to some extent. No change of color and distribution of CGRP-LI in dorsal horn was found in NC0.1 group while reduction was observed in Group NC0.2 when determined in 30 min and on the 5th day. Furthermore,no significant change was observed in 30 min but reduction of positive area was measured on the 5th day in Group LC0.2 compared with control group. No significant difference was found between Group NC0.2 and Group LC0.2 in determining positive area of dorsal horn. Conclusion:Epidural injection of capsaicin increased heat pain threshold significantly. The duration and degree of analgesia and side-effects were positively related to its concentration. Lidocaine could significantly decrease the side-effects of epidural capsaicin.

关 键 词：大鼠 硬膜外间隙 辣椒素镇痛 神经电生理学 免疫组织化学 热痛阈 CGRP-LI 不良反应 

分 类 号：R614[医药卫生—麻醉学] R-332[医药卫生—外科学]