中枢催产素在电针镇痛中的作用

本工作以钾离子透入法引起大鼠甩尾反应的电流强度(mA)为痛反应指标,观察了侧脑室注射催产素(OT)及抗催产素血清(AOTS)对大鼠痛阈和电针镇痛效应的影响。注射50 ngOT 后80min 内,大鼠痛阈比注药前增加20—38%。与注射生理盐水组的痛阈相比有非常明显的增高(p<0.01—0.001),侧脑室注射 OT 后电针期内,痛阈增加139—234%,与生理盐水电针组相比,有显著差异(P<0.05—0.01)。OT 的剂量在25—100ng 范围内,其增强电针镇痛效应有明显的剂量-效应关系。注射 AOTS 后,电针镇痛应明显低于注射正常兔血清(NRS)组(p<0.05—0.01)。上述结果表明,侧脑室注射 OT,既可提高痛阈又可明显地增强电针镇痛效应,而用 AOTS消除内源性 OT 的作用后,电针镇痛效应明显降低。这提示,中枢神经系统内的 OT 在电针镇痛过程中,发挥一定的作用

THE ROLE OF CENTRAL OXYTOCIN IN ELECTROACUPUNC TURE ANALGESIA

The effects of intraventricular injection (ICV) of oxytocin (OT) and antioxytocin serum (AOTS) on the pain threshold and electroacupuncture (EA) analgesia in rats were investigated in this study. The potassium iontophoresis induced tailflick was used to measure the pain threshold. An increase of 20-38% in the pain threshold was observed within 80 min after OT injection (50 ng), while the OT administration (50 ng) in combination with EA produced a dramatic increase of 139-234% in the pain threshold, which was much higher than that in the saline-EA group (P less than 0.05 or 0.01). The OT effect was dose-related in the range between 25-100 ng. Although ICV of AOTS did not change the pain threshold, the EA analgesia became weakened significantly. After injection of AOTS, EA only produced an increase of 47-61% in the pain threshold, while following ICV injection of normal rabbit serum instead of AOTS the EA could cause a rise of 104-123% in the pain threshold. There was a significantly statistical difference between the above two groups (P less than 0.05-0.01). The data indicate that ICV of OT not only elevates the pain threshold, but also enhances the EA effect, and that AOTS attenuates the EA analgesia. These results suggest that endogenous oxytocin in the central nervous system may play a role in the electroacupuncture analgesia.