电针镇痛过程中催产素与内源性阿片肽 是否协同作用

Oxytocin and endogenous opioid peptide are synergistic during electroacupuncture analgesia:Is it a synergistic action?

目的:探讨参与镇痛效应的中脑导水管周围灰质内催产素与内源性脑啡肽及β-内啡肽在电针镇痛中的相互关系。方法:实验于2003-09/10在济宁医学院神经生理研究室进行。取45只Wistar雄性成年大鼠随机分为5组(n=9):①对照组:向右侧中脑导水管周围灰质内注入0.5μL正常兔血清,40min后,再注入0.5μL生理盐水。②抗甲-脑啡肽血清组:注入0.5μL抗甲-脑啡肽血清,位置同对照组,40min后,再注入0.5μL生理盐水。③抗甲-脑啡肽血清+催产素组:注入0.5μL抗甲-脑啡肽血清,位置同前,40min后,再注入1mg/L催产素。④抗β-内啡肽血清组:注入0.5μL抗β-内啡肽血清,位置同前,40min后,再注入0.5μL生理盐水。⑤抗β-内啡肽血清+催产素组:注入0.5μL抗β-内啡肽血清,位置同前,40min后,再注入1mg/L催产素。所有大鼠第2次注射10min后电针双侧“足三里”。以钾离子透入法引起大鼠甩尾反应的电流强度为痛反应的指标,以痛阈变化百分率作为衡量电针镇痛效应的平均针刺效应(简称针效)。结果:进入结果分析37只大鼠。①抗甲-脑啡肽血清对针效影响:抗甲-脑啡肽血清组电针期间和停针后的平均针效低于对照组犤(29.3±9.5)%,(7.03±3.6)%,(64.10±4.74)%,(27.32±5.17)%,P<0.01犦。抗甲-脑啡肽血清+催产素组电针期间和停针后的平均针效高于抗甲-脑啡肽血清组犤(45.4±2.61)%,(27.26±7.16)%,P<0.05～0.01犦。②抗β-内啡肽血清对针效影响:抗β-内啡肽血清组电针期间和停针后的平均针效低于对照组犤(31.87±7.35)%,(15.30±6.15)%,P<0.05～0.01犦。抗β-内啡肽血清+催产素组电针期间和停针后的平均针效高于抗β-内啡肽血清组犤(52.11±3.22)%,(28.61±2.93)%,P<0.05～0.01犦。结论:中脑导水管周围灰质内注入抗脑啡肽血清或抗β-内啡肽血清后能降低电针镇痛的效应,但不能阻断催产素增强电针镇痛的作用;催产素在电针镇痛中的作用不依赖于内源性脑啡肽和β-内啡肽。

AIM：To investigate the interfaces of oxytocin in midbruin periaqueductal gray matter,which is involved in analgesic effect,with endogenous met-enkephalin and β-endorphin during electroacupuncture analgesia. METHODS：Tbe experiment was carried out in the Research Room of Neuruphysiology of Jining Medical College between September and October 2003.Forty-five adult male Wistar rats were randomly divided into 5 groups with 9 ruts in each group：① control group： 0.5 μL normal rabbit serum was injected into the right midbrain periaqueductal gray matter;, After 40 minutes,0.5 μL saline was also injected; ②anti-met-enkephalin serum group： 0.5 μL anti-met-enkephalin serum was injected into the right midbrain periaqueductal gray matter, Mter 40 minutes,0.5 μL saline was also injected; ③anti-met-enkephalin serum oxytocin group：0.5 μL anti-met-enkephalin serum was injected into the right midbruin periaqueductal gray matter,After 40 minutes,0.5 μL oxytocin was also injected; ④anti-β-endorphin serum group,0.5 μL anti-β-endorphin serum was injected into the fight midbruin periaqeductal gray matter,After 40 minutes,0.5 μL saline was also injected; eft）anti-β-endorphin serum ＋oxytocin group：0.5 μL anti-β-endorphin serum was injected into the right midbruin periaqueductal gray matter,After 40 minutes,0.5 μL oxytocin was also injected.Ten minutes after the 2^nd injection,all the rats received electroacupunture at bilateral acpoints of Zusanli.The current intensity of potassium iontophoresis induced tail-flick was used as the index of pain response,the percentage of pain threshold change was used for measuring the average acupuncture effect of the analgensic effect of electroacupuncture（shorted by acupuncture effect）. RESULTS：Finally 37 rats were involved in the analysis of results.① Influence of anti-met-enkephalin serum on acupuncture effect：The average acupuncture effects during and after electroacupuncture were lower in the anti-met-enkephalin serum ＋oxytocin group than in the control group [（29.3±9.5）%,（7.03±3.6）%,（64.10±4.74）%,（27.32±4.17）%,P 〈 0.01],but higher in the anti-met-enkephalin serum oxytocin group than in the anti-met-enkephalin serum group [（45.4±2.61）%,（27.26±7.16）%,P 〈 0.05 to 0.01].② Influence of anti-β-endorphin serum on acupuncture effect：The average acupuncture effects during and after electroacupuncture were lower in the anti-[3-endorphin serum group than in the control group [（31.8±77.35）%, （15.3±06.15）%,P 〈 0.05 to 0.01],but higher in the anti-β-endorphin senam oxytocin group than in the anti-β-endorphin serum group [（52.11± 3.22）%,（28.61±2.93）%,P 〈 0.05 to 0.01]. CONCLUSION：Injection of anti-met-enkephalin serum or anti-β-endorplain into midbrain periaqueductal gray matter can reduce the analgesic effect of electroacupuncture,but it cannot stop oxytocin enhancing the analgesic effect of electroacupuncture;The role of oxytocin in the analgesic effect of electroacupuncture is not dependent on the endogenous met- enkephalin and β-endorphin .