中央灰质注射升压素和催产素受体拮抗剂对刺激视上核镇痛和加强电针镇痛效应的影响

Effect of microinjection of vasopressin and oxytocin receptor antagonists into PAG on the analgesia and the enhancement of electroacupuncture analgesia caused by stimulation of supraoptic nucleus in rats

观察中央灰质（ＰＡＧ）在化学刺激视上核（ＳＯＮ）镇痛和加强电针（ＥＡ）镇痛中的作用。方法：ＰＡＧ内微量注射精氨酸升压素（ＡＶＰ）受体拮抗剂和催产素（ＯＴ）受体拮抗剂后，观察对ＳＯＮ内注射Ｌ－谷氨酸（Ｌ－Ｇｌｕ）引起的镇痛和加强电针镇痛的影响。结果：ＰＡＧ内注射Ｖ１拮抗剂ｄ（ＣＨ２）５Ｔｙｒ（Ｍｅ）ＡＶＰ对化学刺激ＳＯＮ引起的镇痛和加强电针镇痛无影响；Ｖ１Ｖ２受体拮抗剂ｄ（ＣＨ２）５Ｔｙｒ（Ｅｔ）ＤＡＶＰ可部分抑制这种效应；ＰＡＧ内注射２００ｐｇＯＴ受体拮抗剂ｄ（ＣＨ２）５Ｔｙｒ（Ｍｅ）２，Ｏｒｎ８－ｖａｓｏｔｏｃｉｎ（ＯＶＴ）则可完全阻断这种效应。结论：ＰＡＧ参与刺激ＳＯＮ镇痛和加强电针镇痛的过程，ＳＯＮ释放的ＯＴ通过作用于ＰＡＧ内的ＯＴ和Ｖ２受体而发挥镇痛和加强电针镇痛作用。

Objective:To observe the role of PAG in process of analgesia and enhancement of electroacupuncture(EA) analgesia caused by chemical stimulation of supraoptic nucleus(SON) in rats.Methods:Measurement of the changes of pain threshold after microinjection of arginine vasopressin(AVP) and oxytocin(OT) receptor antagonists into PAG following chemical stimulation of SON.Results:OT antagonist reversed the analgesia and the enhancement of EA analgesia caused by stimulation of SON.V1V2 antagonist inhibited partially this action,but V1 antagonist failed to influence this action.Conclusion:PAG may be involved in the analgesia and enhancement of EA analgesia induced by stimulation of SON,OT and V2 receptor in PAG may mediate this action.