Objective To observe the effect of electroacupuncture(EA) on serum tumor necrosis factor-α(TNF-α)

IL-1 and IL-4 levels in rats with chronic inflammatory pain

so as to investigate its underlying mechanism in relieving pain.Methods Forty-eight SD rats were randomized into control

model

EA-unilateral ST36

and EA-bilateral ST36 groups

with 12 rats in each.Chronic inflammatory pain model was established by intradermal injection of Freund's complete adjuvant(0.1mL) into the right paw.EA(2Hz/100Hz

1-2-3mA) was applied to the unilateral "Zusanli"(ST36) and bilateral "Zusanli"(ST36) for 30 min

once every 3 days and continuously for 4 weeks.Serum TNF-α

IL-1 and IL-4 contents were detected by enzyme linked immunosorbent assay.Results Compared with the control group

serum TNF-α

IL-1 and IL-4 contents of the model group increased significantly(P<0.01)

while in comparison with the model group

the levels of the 3 indexes were decreased considerably in both unilateral and bilateral ST36 groups(P<0.01).No significant differences were found between the unilateral ST36 and bilateral ST36 groups in serum TNF-α

IL-1 and IL-4 contents(P>0.05).Conclusion EA can effectively lower serum TNF-α

IL-1 and IL-4 levels in inflammatory pain rats

which may contribute to its effect in relieving inflammatory pain.