Objective: To observe the effect of electroacupuncture(EA) on thymocyte proliferation and apoptosis in surgical trauma-stress rats.Methods: Thirty-six SD rats were evenly randomized into control

model and EA groups.Surgical trauma-stress model was established by making two longitudinal incisions((6 cm) and(5 cm) long) along the median back and abdominal lines and performing visceral exploration manipulation.EA((2 Hz) and(60 Hz) in the frequency

(2.85 s)/(1.05 s) in the duration of pulse-trains

and(1 mA)) was applied to unilateral "Zusanli"(ST 36) and "Lanwei"(EX-LE 7) for(30 min).After killing the rats

the thymus tissue was sampled to be processed into cell suspension for determining the thymocyte proliferation which was expressed by using stimulus index [optical density(OD) of the cellular culture fluid of EA group/OD of control group]

and thymocyte apoptosis was assayed by TdT-mediated dUTP nick end labeling(TUNEL) technique.Results: Results showed that the rates of the apoptotic thymocytes in normal control

model and EA groups were 3.56±3.18%

15.32±4.67%

and 7.42±4.19% respectively;while the SI values of the aforementioned 3 groups were 1.96±0.09

1.40±0.10 and 1.65±0.10 separately.It indicated that after trauma-stress

the apoptosis of the thymus increased markedly and the cellular proliferation lowered significantly(P<0.01

0.001);following EA

the aforementioned effects of surgical trauma-stress were suppressed apparently(P<0.05).Conclusion: EA can improve trauma-stress induced immunodysfunction via inhibiting the apoptosis and facilitating the proliferation of thymocytes.