小鼠鞘内注射PGE_1对不同性质疼痛调控作用的异质性

DIFFERENTIAL EFFECTS OF INTRATHECAL ADMINISTRATION OF PROSTAGLANDIN E_1 ON DIFFERENT PAIN MODALITIES IN MICE

目的 :研究PGE1在脊髓水平对不同性质疼痛的调控作用。方法 :清醒小鼠鞘内注射法给药 ,用热水缩尾法 ,福尔马林实验 ,冰醋酸扭体法等三种方法测痛。结果 :在热痛模型上 ,PGE10 .1ng～ 0 .1 μg/只使小鼠痛阈显著降低 ,1 0ng时最明显 ,而在较大剂量 1 μg/只无明显作用。福尔马林实验中 ,PGE10 .1 ,1 0ng/只无显著作用 0 .1 μg/只抑制其I相反应 ,1 μg/只显著抑制其Ⅰ、Ⅱ相反应。在冰醋酸扭体模型中PGE10 .1 ,1 0ng/只无明显效果。 0 .1 ,1 μg/只降低小鼠扭体次数呈镇痛作用。结论 :PGE1在脊髓对不同性质疼痛调控作用有本质差别 ,即对热痛有易化作用 。

Aim: The effects of intrathecal injection of prostaglandin E 1 on pain in conscious mice were evaluated by tail curl test (TCT), formalin test and acetic acid writhing test. On TCT, prostaglandin E 1 markedly decreased tail curl latency (TCL) at dose of 0.1ng～0.1μg/mouse, but had no effect at higher dose (1μg/mouse). Different results were observed on formalin test: PGE 1 at dose of 0.1μg/mouse only inhibited the first phase, whereas at dose of 1μg/mouse, induced significant decrease of pain response in both the first and the second phase. PGE 1 showed an analgesic effect on acetic acid induced writhing test at doses of 0.1 and 1μg/mouse. No marked effect were observed on both formarlin test and acetic acid writhing test at doses of 0.1 and 10ng/mouse. The results suggest that PGE 1 induced different effects on different pain modalities at spinal level. PGE 1 had a hyperalgesic effect for thermal pain and a hypoalgesic effect on chemically induced pain.