下丘脑室旁核加压素能神经元参与电针刺激对实验性内脏痛的抑制

INVOLVEMENT OF VASOPRESSINERGIC NEURONS OF PARAVENTRICULAR NUCLEUS IN THE ELECTROACUPUNCTURE-INDUCED OF EXPERIMENTAL VISCERAL PAIN IN RATS

本实验采用内脏痛的实验模型,探讨室旁核中的加压素在针刺抑制内脏痛中的作用。实验结果如下:(1)大鼠在在射酒石酸锑钾(0.1％,10ml/kg,i.p.)后,出现可定量的扭体反应,能作为观察内脏痛的客观指标。(2)电针对内脏痛有抑制效应,即具有镇痛作用。(3)电刺激室旁核,能加强电针对内脏痛的抑制效应,损毁室旁核,则此抑制效应基本消失。(4)脑室注射加压素抗血清(14μl)或加压素拮抗剂[d(CH_2)_5Tyr(Me)-AVP,500ng/5μl]都能明显减弱电针的抑制效应。(5)腹腔注射加压素拮抗剂(10μg/kg),不能翻转电针的抑制效应。上述实验结果表明,下丘脑室旁核的加压素能神经元参与了电针刺激对实验性内脏痛的抑制。

It has been demonstrated in animal model of somatic pain that hypotha-lamic paraventricular nucleus (PVN) participates in acupuncture analgesia.probably by mediation of vasopressin release. The role of PVN in acupunctureanalgesia for experimental visceral pain in rats was further investigated in thepresent study. Experimental results demonstrated that electroacupuncturecould inhibit the writhing response, produced by intraperitoneal injection ofantimonium potassium tartrate and this inhibitory effect could be enhanced byelectrical stimulation of PVN, but decreased by electrolytical lesion of PVN,intracerebroventricular injection of vasopressin antiserum (14 μl) or the vasopres-sin antagonist, d(CH_2)_5Tyr(Me)-AVP (500 ng/5 μl). Intraperitoneal adminis-tration of the latter drug (10 μg/kg),however, was ineffective. The above ex-perimental results suggest that vasopressinergic neurons in PVN also participatein the inhibition of visceral pain by electroacupuncture.