野罂粟总生物碱镇痛作用部位的研究

Analgesic sites of total alkaloids in Papaver nudicaule

目的研究野罂粟总生物碱(TAPN)的镇痛作用部位。方法采用小鼠福尔马林试验,ip和iv两种给药途径对醋酸所致小鼠扭体反应所得ED50进行比较,小鼠和大鼠侧脑室给药法(icv)、脊髓蛛网膜下腔给药法(ith)确定TAPN的镇痛作用部位。结果TAPNip给药对福尔马林致痛的早、晚两相疼痛反应均有抑制作用,对晚期相更为敏感。ip或iv等剂量的TAPN,对小鼠扭体反应的抑制程度多以ip为强,且测得TAPN给药后各个时间段的ED50(ip)均小于ED50(iv)。TAPN微量icv给药具有明显的镇痛作用,而微量ith给药无明显的镇痛作用。结论TAPN的镇痛作用部位主要在外周,同时也具有中枢镇静作用,且在脊髓以上水平。

Objective To study the analgesic sites and mechanism of total alkaloids in Papaver nudicaule (TAPN). Methods The sites of analgesic action of TAPN were observed by adopting Formalin test and two different routes of intracerebroventricular (icv), intrathecal (ith) in mice and rats and comparing ED 50 of TAPN in writhing reaction in mice induced by acetic acid by ip and iv administration. Results TAPN significantly lowered pain score of the early and late phase of Formalin response and was more sensitive in the late phase. Inhibition of TAPN at the same dose by ip administration in writhing reaction in mice induced by acetic acid was stronger than that by iv. The ED 50 value of TAPN at any time by ip administration was lower than that by iv administration. By means of central microinjection, TAPN by icv administration induced remarkable analgesic effect in mice, but TAPN by ith administration had no significant analgesic effect. Conclusion The sites of analgesic action of TAPN are mainly at periphery. TAPN has also central analgesic effect, and the site may be at the level above the spinal cord.