据报道

针刺镇痛时脑内去甲肾上腺素(NE)的含量明显降低;损毁 NE 能神经元胞体密集分布的蓝斑或上行途径

或者用双硫醒等抑制 NE 合成以降低脑内 NE 含量

均可增强针刺镇痛;刺激蓝斑或注射 NE 前体二羟基苯丝氨酸使脑内 NE 含量增加时

可对抗针刺Sixty of rats were randomly divided into 6 groups:(1)Control; (2)Electroacupuncture;(3)phentolamine;(4)phentolamine plus electroacupuncture;(5)propranolol;(6)propranolol plus electroacupu- ncture.The concentrations of 5-HT and 5-HIAA in oblongata plus pons

subthalamus

hippocampus

striatum

midbrain or cortex were determined by fluorospectrophotometry. Not only pain threshold

but also the contents of 5-HT and 5-HIAA in the oblongata and the midbrain were increased by electroacupuncture. Both the analgesic effect and the levels of 5-HT and 5-HIAA in the striatum were accelerated

by a pre-injection of phentolamine

a blocker of a receptor.The elecctroacupuncture analgesia was partially blocked and the increases of 5-HT and 5-HIAA in the oblongata plus pons and the midbrain

induced by electroacupuncture

were inhibited

while the level of 5-HT in the hippocampus was rose and the content of 5-HIAA in the cortex was decreased by propranolol

a blocker of β receptor. These results suggest that both α and β receptors play an important role and can regulate the metabolism of 5-HT in brain in acupuncture analgesia.