BACKGROUND: It has been found in recent years that STAT3 widely distributes in nervous system, including hippocampal CA1-3 region, dentate gyrus and cerebral neocortex, etc. Ischemic brain injury can cause the release of some cytokines and growth factors, while electro-acupuncture may have multi-level, multi-channel and multi-target protective and interventional effects on ischemic brain injury. OBJECTIVE: To observe the effects of electro-acupuncture on STAT3 expression and nuclear translocation in hippocampal CA1 region of rat models of brain ischemia/reperfusion. DESIGN: Randomized and controlled observation. SETTING: Staff Room of Acupuncture and Moxibustion, Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine; Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Seventy-two healthy SD rats, of clean degree and either gender, weighing (200±20) g, were provided by the Experimental Animal Center of Hubei College of Traditional Chinese Medicine. STAT3 monoclonal antibody was purchased from Santa Cruz Company, USA, and G-6805 electro-acupuncture instrument was purchased from Shanghai Medical Electronic Instruments Factory. METHODS: This experiment was carried out in the comprehensive laboratory of Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine between September 2005 and February 2006. Seventy-two rats were randomly divided into 4 groups: ① control group(n =6): Untouched. ② Sham-operation group (n =18): Artery was isolated, but without inserting thread bolt.③ Model group (n =24): Rat models of local brain ischemia/reperfusion were established with modified suture occlusion. ④Electro-acupuncture group (n =24): Dazhui and bilateral Neiguan points were selected for electro-acupuncture treatment. No. 28 acupuncture needle of 3.33 cm was used in the treatment. A G-6085 electro-acupuncture instrument with continuous wave, frequency of 120 times/min, intensity of 1 mA, 30 min/time, was used. Acupuncture was conducted firstly at ischemia/reperfusion 3 hours, then once every 12 hours. STAT3 positive nuclear translocation in hippocampal CA1 region of rats was observed with immunohistochemical method at 24, 48 and 72 hours after brain ishcemia/reperfusion, and then STAT3 positive cells were counted. MAIN OUTCOME MEASURES: STAT3 positive cells and nuclear translocation in hippocampal CA1 region of rats in each group. RESULTS: All the 72 rats were involved in the result analysis. ①In the control group and sham-operation group, STAT3 positive cells with light cytoplasm and nucleus were decreased , and nuclear translocation was not found. ② In the model group, STAT3 positive cells were mostly found in the cytoplasm of the hippocampal CA1 region at the ischemic side of rats after ischemia/reperfusion 24 hours. They were significantly more than those in the sham-operation group and control group [(18.00±2.68), (9.00±1.35), (8.00±1.22) cells/ mm2, P < 0.01], but cells with nuclear reaction were fewer; At ischemia/reperfusion 48 and 72 hours, STAT3 positive cells were increased, and they were significantly more than those of sham-operation group [(25.00±3.23), (35.00±3.52) cells/mm2, (13.00±1.93), (12.00±1.24) cells/mm2, P < 0.01]. Positive cells with nuclear reaction were found dark-stained. ③At ischemia/reperfusion 24, 48 and 72 hours, STAT3 positive cells were strongly expressed in hippocampal CA1 region at ischemic side of rats of electro-acupuncture group, and they were significantly more than those of model group [(25±3.52), (50±6.31), (75±8.09) cells/mm2, P < 0.01]. STAT3 positive cells were gradually enhanced with time, and considerable STAT3 nuclear positive reaction cells were found. CONCLUSION: Electro-acupuncture can activate STAT3 protein expression in hippocampal tissue of rats with local brain ischemia/reperfusion, promote STAT3 nuclear translocation and function its neuroprotective effect. BACKGROUND: It has been found in recent years that STAT3 widely distributes in nervous system, including hippocampal CA1-3 region, dentate gyrus and cerebral neocortex, etc. Ischemic brain injury can cause the release of some cytokines and growth factors, while electro-acupuncture OBJECTIVE: To observe the effects of electro-acupuncture on STAT3 expression and nuclear translocation in hippocampal CA1 region of rat models of brain ischemia / reperfusion . DESIGN: Randomized and controlled observation. SETTING: Staff Room of Acupuncture and Moxibustion, Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine; Tongji Medical College, Huazhong University of Science and Technology. MATERIALS: Seventy-two healthy SD rats , of clean degree and either gender, weighing (200 ± 20) g, were provided by the Experimental Animal Center of Hubei College of Tr METHODS: This experiment was carried out in the comprehensive laboratory of Department of Acupuncture and Bone Injury, Hubei College of Traditional Chinese Medicine between September 2005 and February 2006. Seventy-two rats were randomly divided into 4 groups: ① control group (n = 6): Untouched. ② Sham-operation group (n = 18) (n = 24): Rat models of local brain ischemia / reperfusion were established with modified suture occlusion. ④ Electro-acupuncture group (n = 24): Dazhui and bilateral Neiguan points were selected for electro-acupuncture treatment. No. 28 acupuncture needle of 3.33 cm was used in the treatment. A G-6085 electro-acupuncture instrument with continuous wave, frequency of 120 times / min, intensit y of 1 mA, 30 min / time, was used. Acupuncture was initially implanted with ischemia / reperfusion for 3 hours, then once every 12 hours. STAT3 positive nuclear translocation in hippocampal CA1 region of rats was observed with immunohistochemical method at 24, 48 and 72 hours after brain MAIN OUTCOME MEASURES: STAT3 positive cells and nuclear translocation in hippocampal CA1 region of rats in each group. RESULTS: All the 72 rats were involved in the result analysis. ① In the control group and sham-operation group, STAT3 positive cells with light cytoplasm and nucleus were decreased, and nuclear translocation was not found. ② In the model group, STAT3 positive cells were mostly found in the cytoplasm of the hippocampal CA1 region at the ischemic side of rats after They were significantly more than those in the sham-operation group and control group [(18.00 ± 2.68), (9.00 ± 1.35), (8.00 ± 1.22) cells / mm2, P < 0.01), but cells with nuclear reaction were fewer; At ischemia / reperfusion 48 and 72 hours, STAT3 positive cells were increased, and they were significantly more than those of sham-operation group [(25.00 ± 3.23), (35.00 ± 3.52) (13.00 ± 1.93), (12.00 ± 1.24) cells / mm2, P <0.01]. Positive cells with nuclear reaction were found dark-stained. ③At ischemia / reperfusion 24, 48 and 72 hours, STAT3 positive cells were strongly expressed in hippocampal CA1 region at ischemic side of rats of electro-acupuncture group, and they were significantly more than those of model group [(25 ± 3.52), (50 ± 6.31), (75 ± 8.09) cells / mm2, P <0.01]. STAT3 positive cells were gradually enhanced with time, and STAT3 nuclear positive reaction cells were found. CONCLUSION: Electro-acupuncture can activate STAT3 protein expression in hippocampal tissue of rats with local brain ischemia / reperfusion, promote STAT3 nuclear translocation and function its neuroprotective effect.