中缝大核内催产素在大鼠痛行为调制中的作用

The role of oxytocin in pain modulation in the nucleus raphe magnus of rats

目的 探讨中缝大核 (NRM)内催产素 (OT)在痛行为调制中的作用 ,及其和内源性 5 HT在痛行为调制中的关系。方法 以钾离子透入法引起大鼠甩尾反应的电流强度 (mA)为痛行为反应指标 ,测定动物痛阈 ,观察NRM内催产素对大鼠痛行为反应的影响。结果 NRM内注入催产素后 ,大鼠的痛阈明显增加 ;注入抗催产素血清后 ,大鼠的痛阈则明显降低。NRM内注入噻庚啶后 ,可阻断OT镇痛的效应。结论 NRM内的催产素在痛行为调制的复杂过程中发挥着一定作用 ,且其效应可能是通过内源性 5

Objective To study the effect of Oxytocin(OT) on pain modulation in nucleus raphe magnus(NRM) and its relation to endogenous 5 HT.Methods The potassium iontophoresis induced tail flick was used to measure the pain threshold. The effect of NRM injection of OT,anti OT serum (AOTS) and Cyproheptadin(C) on the pain threshold in the rat was investigated. Results OT administration into NRM induced a enhancement of pain threshold.Injection of AOTS reduced the pain threshold significantly. Furthermore,pre injection of C into NRM could weaken analgesia effect of OT.Conclusion There results indicate that OT in NRM is involved in pain modulation . The effect of OT may be partly conducted by endogenous 5 HT.