Objective:To observe the effect of peripheral norepinephrine (NE) level on acupuncture analgesia.Methods:33 cases of cholecystectomy patients were randomly divided into group A (acupuncture combined with extradural-T 4～12 administration of small dose of analgesic

lidocaine 1.5%

4 mL)

group B (electrical stimulation of acupoint skin via cutaneous electrodes combined with extradural administration of small dose of analgesic)and group C (control group

only extradural administration of small dose of analgesic). Each group contained 11 cases respectively. The plasma NE

epinephrine(E) and dopamine (DA) concentrations were determined on the day before operation

during operation (30 minutes after anesthesia) and 3 days after operation in all the cases using high pressure liquid chromatography (HPLC)-electrochemical technique.Bilateral Zusanli (ST 36) and Neiguan (PC 6) were used and stimulated electrically with frequency 2/15 Hz

intermittent waves

and 2 ～ 3 mA for group A and 13 mA for group B.Results: The results showed that in group A and B

the plasma NE concentrations reduced respectively from 3.85±1.47 ng/mL and 2.90±1.49 ng/mL of pre operation to 2.28±0.84 ng/mL and 2.34± 1.57 ng/mL during operation. There were significant differences between pre and post operation in NE level in both groups (P<0.01).While in group C

the NE level increased from 2.73±1.26 ng/mL to 2.89±1.46 ng/mL during operation.The contents of plasma E in group A

B and C increased obviously and respectively from 2.33±0.58 ng/mL

1.74±1.22 ng/mL and 1.85±0.77 ng/mL of pre operation up to 3.67±1.39 ng/mL

3.19±1.92 ng/mL and 2.51±1.62 ng/mL during operation (P<0.01). The plasma DA contents in the 3 groups also increased during operation.All the values of plasma NE

E and DA on the 3rd day after operation in the 3 groups were close to the basic levels of pre operation.It indicates that either acupuncture or acupoint superficial electrical stimulation combined with extradural anesthesia assumes a suppressive action on the activity of sympathetic nerve during surgical operation. The effect of acupuncture analgesia is mainly related to the plasma NE level rather than plasma E and DA.The lower the plasma NE level (group A and B)

the better is the analgesic effect. Conclusion: Acupuncture and acupoint surface electrical stimulation combined with extradural administration of small dose of analgesic may be capable of inhibiting the stress response caused by surgical operation in the human body.