Zhongguo Yao Li Xue Bao. 1993 Sep; 14(5): 388-92.
Chlorpromazine attenuated electroacupuncture analgesia in conscious rabbits.
Department of Neurobiology, School of Basic Medical Sciences, Shanghai Medical University, China.
By measuring the defense behavior in response to the noxious stimulation induced by potassium iontophoresis on ear-lobe skin of conscious rabbit, chlorpromazine (CPZ) (0.5 mg.kg-1, i.v.) induced hyperalgesia, whereas it significantly attenuated electroacupuncture analgesia (EAA) efficacy. Monoamines and their metabolites in cerebrospinal fluid (CSF) were measured by high pressure liquid chromatography with electrochemical detector (HPLC-ECD) while the attenuation effect of CPZ on EAA was observed. CPZ markedly enhanced 3,4-dihydroxyphenylacetic acid (DOPAC) (P < 0.05) and homovanillic acid (HVA) (P < 0.01) contents in CSF both in the presence and absence of electroacupuncture. CPZ attenuated EAA with elevations of either DOPAC or HVA concentrations in CSF. There was a positive correlation between the increase of DOPAC or HVA content in CSF and the attenuation effect of CPZ on EAA (P < 0.05). These results suggested that the activation of dopamine system was unfavorable for EAA.