在过去的交叉循环实验中曾提示外周单胺类物质可能参与了电针供血猫对刺激未受针刺的受血猫内脏大神经引起的皮层诱发电位的抑制效应。随后又采用血浴器官生物测定法初步证实电针穴位确能促使猫外周单胺类物质的释放。本工作进一步观察从颈动脉注射单胺类物质对平均迭加的皮层The inhibitory effects of intracarotid injections of serotonin

nor-adrenaline or adrenaline indifferent doses on averaging cortical splanchnic evoked potentials

indicating the central pain response

were observed in 27 cats.Furthermore

combination of intracarotid injection of noradrenaline in sub-effective dose and electro-needling the acupoint “Weishu” with low intensity had a facilitating effecton the inhibition.The results suggest that the monoamines in peripheral circulation may enter thebrain and inhibit the cortical electroactivity

and may have a facilitating effect on acupunctureanalgesia.This work supports the results observed in our previous cross-circulation experiments

i.e.humoral factors play a role in the central action of acupuncture analgesia.