Zhongguo Zhong Xi Yi Jie He Za Zhi. 2001 Feb; 21(2): 115-8.

[Changes of cerebral beta-endorphin in rats treated with combination therapy of melatonin and electroacupuncture]

Zhou MM, Yu CX, Wang MZ.

Department of Neurobiology, Insitute of Acupuncture Research, State Key Laboratory of Medical Neurobiology, Medical Center of Fudan University, Shanghai 200032.

OBJECTIVE: To explore the strengthening of acupuncture analgesic mechanism on the level of beta-endorphin and proopimelanocortin mRNA expression in the arcuate nucleus of hypothalamus in rats following electroacupuncture (EA) combined with melatonin (MEL). METHODS: Integrated optical density (IOD) was measured by ABC immuno-histochemical and in situ hybridization technique with computerized image processing. The rat's brain was coronally sectioned after combination of EA and MEL. RESULTS: IOD of beta-endorphin-like immunopositive substance in rat's brain was lowered significantly, which was measured after MEL (60 mg/kg) was injected intraperitoneally and followed by EA 30 min later for 30 min, and the IOD of cerebral POMC mRNA positive substance increased significantly 10 hrs later. CONCLUSION: The mechanism of MEL in enhancing EA analgesic effect might be related with the release and synthesis of beta-endorphin.