Effects Of Electroacupuncture On IL-6 And TNF-α Expression In Rats With Focal Cerebral Ischemia

PurposeTo examine the effects of electroacupuncture(EA) on IL-6 and TNF- a expression in cerebral ischemia rats, and to provide the experimental evidence to explore the immunologic mechanisms of EA ameliorating ischemic cerebral damages.MethodsSD rats were divided into four groups randomly: Normal control group, sham operation group, ischemia groups and EA groups. According to ischemia time, 1,3,7 or 14 days, ischemia groups and EA groups were divided into four subgroups respectively. To prepare focal cerebral ischemia model, the middle cerebral artery (MCA) of rat was occluded by a monofilament. HE staining was used to observe cerebral pathologic changes following ischemia and EA. Immunohistochemical method and radioimmunoassay were used to investigate the effects of EA on IL-6 and TNF- a expression in ischemic area and serum at various time points after cerebral ischemia.Results(1) After middle cerebral artery occlusion(MCAO), HE staining indicated a slight swell ofneuron and glial cells in the infarcted area 1 day after ischemia, a shrinkage and deformation of the neuron body 3 days after ischemia, pyknosis of the nucleus with intense eosiniphilia of the cytoplasm 7 days after ischemia and loose intercellular substance 14 days after ischemia. The pathologic alterations occurred to a lesser degree in EA 7,14 days groups compared with ischemia groups.(2) The number of IL-6 and TNF- a positive cells in ischemic cerebral cortex and striatum increased and reached the peak 3 days and 1 day after ischemia, respectively. Fewer positive cells were observed in striatum than cerebral cortex. The number of IL-6 positive cells of EA l,3,7days groups was raised(P<0.05), while the number of TNF- a positive cells of EA l,3,7days groups was decreased(P<0.05), as compared with that of ischemia groups.(3) Serum IL-6 and TNF- a level also increased with a peak at 1 day after ischemia. Serum IL-6 level of EA 3,7days groups was raised(P<0.05), while serum TNF- a2level of EA 3,7,14days groups was decreased(P<0.05) , as compared with that of ischemia groups.ConclusionThe expression of IL-6 and TNF- a increased after cerebral ischemia. EA couldupregulate IL-6 expression and downregulate TNF- a expression, which might be one of the mechanisms of EA protecting against ischemic cerebral damage.