Electroacupuncture (EA) has been used to alleviate the immuno suppression o n account of its modulating function. Many investigations showed that EA could m odulate immune function through the actions of sympathetic nervous system and hy pothalamic pituitary adrenal axis. It was also indicated that EA stimulation o f "Z usanli" (ST 36) point could improve the immuno suppression induced by trauma. T he present experiment was to elucidate the central mechanism of EA on immune modul ation. Using immunohistochemistry and in situ hybridization techniques

it was o bserved that the endogenous orphanin FQ (OFQ) and its receptor opioid receptor l ike receptor (OP 4) transcripts were widely distributed in the central nervous sy stem (CNS) of normal rats

but the OFQ immuno reactive cells in hippocampus

ce r ebral cortex and hypothalamus in traumatic group were significantly decreased to 25.2±5.07

31.1±10.50

24.5±5.44

compared with control group (72.4±7.99

1 15.7±19.47

64.1±8.90) (P<0.05). After EA stimulation of "Zusanli" point the expression of OFQ was markedly increased

the OFQ immuno reactive cel ls were recovered to 60.0±5.48 in hippocampus

111.0±11.64 in cerebral cortex

and 64.0±10.01 in hypothalamus (P<0.05). The similar changes were al so observed in OP 4 mRNA transcripts in the CNS. However

different changes occu rred in IL 1β transcripts in the CNS. The IL 1β mRNA immuno reactive cells were 15.9±3.93

7.9± 3.07

8.6±2.41 in control group; 38.1±6.33

78.9±5. 13

49.1±9.84 in traumatic group; 22.7± 3.30

30.8±8.74

11.6±2.80 in trauma+ EA g roup

respectively. It indicated that the IL 1β mRNA transcripts were augm ente d by trauma and inhibited by EA. The above results suggested that OFQ had a clos e correlation with IL 1β in the CNS. The neuroimmune modulation of EA may be d ependent on the sustaining precise interactions between OFQ and IL 1β.