Effects of fenfluramine combined with electroacupuncture on monoamine release in periaqueductal gray of rat brain

AIM: To study the changes of monoamines in ventrolatoral periaqueductal gra y of rat brain before and after electroacupuncture (EA) analgesia (EAA) was enhanced by fenfluramine (Fen), a 5-hydroxytryptamine (5-HT) releaser. MET HODS: Monoamines were collected by in vivo microdialysis and measured by HP LC connected with electrochemical detector. RESULTS: The level of norepinep hrine (Nor) after EA was decreased (P < 0.05 vs NS group). The contents of 5-HT, 5-hydroxyindol acetic acid (5-HIAA), dopamine (DA), and homovanillic acid (HVA) in periaqueductal gray dialysate were increased (P<0.05 vs NS gr oup). When Fen was combined with EA, the level of 5-HT and 5-HIAA were furt her increased (P <0.05 vs NS + EA group). There was no obvious change of No r, DA, and HVA. CONCLUSION: Fen potentiating EAA may be related to further activation of serotoninergic system.