Trauma stress is a well known entity and may be defined as a threat to the immune function. The effect of melatonin(MT) and electroacupuncture(EA) treatme nt on the cytotoxic activity of natural killer(NK) cells

the proliferative resp onse of spleen lymphocytes to ConA and the dynamic changes of the induction of i nterleukin 2(IL 2) in traumatic rats were evaluated in this study.The results showed that 5 mg/kg (ip)melatonin was able to recover the lowered NK c ell activity in trauma rats 24 hours after operation (P<0.05).Al so lymphoc yte proliferation and the induction of IL 2 production were reversed by MT trea tment (P<0.05

P<0.05).EA stimulation of "Zusanli"(ST 36) a nd "Lanwei"(Extra 37) points also obviously improved the immunosuppression pro duced by trauma. MT combined wit h EA could further modulate the depressed immune function(P<0.01)

whi ch was significantly superior to melatonin or EA alone (P<0.05

P<0.05). These results indicate that MT and/or EA can recover NK cel l activity

lymphocyte proliferative capacity and the induction of IL 2 producti on

but the mechanism deserves further investigation.