小鼠电针镇痛模型的建立与实验观察

A mouse model for electroacupuncture induced analgesia and its experimental investigation

目的：建立小鼠电针镇痛模型，在不同品系小鼠上观察各种电针参数引起的电针镇痛效果。方法：应用ＬＨ型ＨＡＮＳ刺激仪，采用辐射热甩尾测痛法，比较了６种品系小鼠的电针镇痛效应。结果：（１）品系的差异：１００Ｈｚ电针时ＤＢＡ／２品系的镇痛效果显著优于其它品系，２Ｈｚ电针时ＤＢＡ／２品系和ＢＡＬＢ／ｃ品系显著优于ＩＣＲ品系；（２）性别差异：２Ｈｚ电针ＤＢＡ／２、Ｃ５７、ＢＡＬＢ／ｃ３种品系的雌鼠优于雄鼠，１００Ｈｚ电针仅ＢＡＬＢ／ｃ品系的雌鼠优于雄鼠；（３）刺激强度方面：１２２ｍＡ组针效显著优于０．５１．５２．５ｍＡ组或１１．５２ｍＡ组；（４）ＤＢＡ／２和Ｃ５７品系小鼠的电针镇痛与吗啡镇痛呈正相关性；（５）纳洛酮翻转：剂量为１ｍｇ·ｋｇ－１的纳络酮能翻转２Ｈｚ电针效果；而翻转１００Ｈｚ电针效果，则需剂量为２５ｍｇ·ｋｇ－１的纳络酮。结论：小鼠电针镇痛存在品系（遗传背景）和性别差异。阿片受体参与了小鼠电针镇痛，低频和高频电针镇痛分别由不同亚型的阿片受体介导。

Objective: To establish a mouse model for electroacupuncture induced analgesia (EAA) and to characterize optimal parameters of electroucupuncture (EA) and the effect of EAA in different strains of mice. Methods: Radiant heat tail flick latency was used for nociceptive test. Han's acupoint nerve stimulator (HANS, LH series) was used for EA and 6 strains of mice were screened for the effect of EAA. Results: (1) Strain difference: DBA/2 mice showed significantly better analgesic effect than other 5 strains in 100 Hz EAA, whereas in 2 Hz EAA, only DBA/2 and BALB/c mice showed significantly stronger analgesia compared with ICR mice. (2) Sex difference: Female mice showed better EAA than male. A statistically significant gender difference was seen in 3 strains of mice (DBA/2, C57, BALB/c) under 2 Hz EAA, but only in one strain (BALB/c) under 100 Hz EAA. (3) Stimulation intensity: An increasing intensity of 1 2 2 mA in 10 min steps seemed optimal for both 2 Hz and 100 Hz EAA. (4) A positive correlation was observed between morphine analgesia and 100 Hz EA analgesia in DBA/2 and C57 mice. (5) EAA could be significantly reversed by the opioid antagonist naloxone at doses of 1 mg·kg -1 for 2 Hz EAA and 25 mg·kg -1 (but not 1 and 5 mg·kg -1 ) for 100 Hz EAA. Conclusion: (1) Comparison of the effect of EAA in 6 strains of mice revealed a significant strain and gender difference. (2) Naloxone blockade strategy revealed that different types of opioid receptors are involved in the mediation of low and high frequency EAA in mice.