抗阿片肽血清对脊髓内催产素镇痛作用的影响

Effect of anti-opioid peptide sera on analgesia of oxytocin in spinal cord of rats

目的探讨脊髓内催产素(OT)与内源性脑啡肽和强啡肽A_(1～13)在痛觉调制中的关系。方法以钾离子透人法引起大鼠甩尾反应的电流强度(mA)为痛行为反应的指标,观察向脊髓蛛网膜下腔内注入抗甲-脑啡肽血清、抗强啡肽A_(1～13)血清和OT对动物痛阈的影响。结果脊髓内注入抗甲-脑啡肽血清、抗强啡肽A_(1～13)血清后,大鼠痛阈与注药前相比分别变化(-23．32±2．81)%～(一12．11±2．13)%和(-26．33±5．42)%～(-13．21±2．32)%,与对照组相比痛阈明显降低；但在注射OT前预先注射抗甲-脑啡肽血清或抗强啡肽A_(1～13)血清,大鼠痛阈较注药前增加(8．96±3．02)%～(70．22±6．16)%和(5．56±2．63)%～(61．21±5．21)%,抗甲-脑啡肽血清或抗强啡肽A_(1～13)血清均不能完全阻断OT的镇痛效应。结论脊髓内OT在痛觉调制中的作用不完全依赖于脊髓内的内源性脑啡肽和强啡肽A_(1～13)。

Objective To study the effect of oxytocin（OT） on pain modulation in spinal cord and its relation to endogenous met-enkephalin and dynorphin A1-13. Methods The potassium iontophoresis induced tail-flick was used to measure the pain threshold. Results OT administration induced an enhancement of pain threshold . Furthermore,pre-injection of AMEKS or ADYNS in spinal cord not could weaken analgesia effect of OT. Conclusion These data suggest the enhancement of analgesia by OT is not dependent upon the met-enkephalin and dynorphin A1-13 in spinal cord.