[Effect of ketamine on acupuncture analgesia]

There were different opinions about whether ketamine has an antagonistic effect on electroacupuncture (EA) analgesia. The aim of this paper was to investigate the effect of ketamine on EA. The rats were divided into three groups: 4 mg/kg, 20 mg/kg of ketamine in doses, and normal saline groups. Ketamine was injected peritoneally in dosage of 4 mg/kg and 20 mg/kg respectively. Tail flick latency (TFL) and vocalization threshold (VT) were taken as the indices of pain responses. Changqiang and Yaoshu acupoints were selected for electroacupuncture. It was observed that the analgesia effects of EA were attenuated after injection of ketamine either in 4 mg/kg group of 20 mg/kg group. The results indicate that 4 mg/kg or 20 mg/kg ketamine in doses has an antagonistic effect on EA analgesia, suggesting that attention should be paid to the dosage when ketamine is used for EA analgesia.