套筒制动及扎针对小鼠电针实验中镇痛的贡献

目的 :动物电针镇痛研究大都需要将动物制动和扎针 ,人们难以确定所观察到的镇痛作用中有无制动和扎针带来的应激性镇痛。本实验在观察到 2Hz电针对套筒制动的Swiss Webster小鼠具有镇痛作用的基础上 ,试图分析小鼠电针镇痛实验中套筒制动和扎针对镇痛的贡献。方法 :纸板 /布兜制动的动物作为对照组 (n =8) ,此法对动物的制动作用短暂而轻微。塑料套筒制动的实验组动物根据扎入针灸针有否又分为不扎针 (n =8)和扎针 (n =8)两组。以 48℃热水甩尾潜伏期 (TWL)作为测痛指标。结果 :塑料套筒制动的实验组小鼠 ,无论是不扎针还是扎针 ,其TWL均较纸板 /布兜制动组延长。结论 :电针实验中观察到的镇痛 ,除了来源于电流刺激外 ,制动及扎针引起的痛阈升高也可能是重要因素

Contributions of Cylindrical Restraint and Needle Insertion to the Analgesia Obtained from Electroacupuncture in Mice

Objective: In almost all researches about electroacupuncture (EA) analgesi a on animals, restraint and needle insertion is necessary. It is difficult to te ll whether the restraint and needle in the EA experiment insertion can result in stress induced analgesia. On the basis that 2 Hz EA could induce analgesia in Swiss Webster mice, the present paper aims to investigate the contributions of cylindrical restraint and needle insertion to the analgesia obtained from electr oacupuncture in mice.Methods: The animals restrained with a transient , gentle cardboard/clothing holder served as the control group(n=8), t he animals rest rained with the cylindrical holder were divided into two treatment groups accord ing to whether there were inserted needles in the acupoints (ST 36 and SP 6). Th e pain thresholds were assessed with tail withdrawal latencies (TWL) in 48 ℃ ho t water.Results: The TWLs in animals restrained with cylindrical holder, with or without needle insertion (4.0±0.1 sec and 4.5±0.1 sec from the 30 th to 90 th min, n=56), were much higher than those in a nimals res trained with cardboard/cloth holder (3.2±0.1 sec, n=112).Con clusion: WT the analgesia obtained in the EA experiments results from not only the elec trical stimulation, bu t also the increased pain threshold induced by holder immobilization and needle insertion.