[Effect of electroacupuncture on expression of signal transducer and activator of transcription 3 in focal ischemic cerebral tissue in cerebral ischemia rats].

Objective: To observe the effect of electroacupuncture (EA) intervention on expression of signal transducer and activator of transcription 3 (STAT 3) in the focal ischemic cerebral tissue, so as to study its mechanism underlying improving ischemic stroke.

Methods: A total of 150 SD rats were randomized into sham operation (control) group, cerebral ischemia (CI) model (model) group and EA group which were further randomly divided into 2 hour (2 h), 1 day (1 d), 3 d, 1 week (1 W) and 3 W subgroups (n = 6/subgroup for immunohistochemistry, n = 4/subgroup for Western blot). CI model was established by occlusion of the middle cerebral artery with electro-coagulation method. EA (3 Hz/20 Hz, 2-3 V) was applied to "Baihui" (GV 20) and "Dazhui "(GV 14) for 30 min. The expression of cerebral STAT 3 was detected by immunofluorescence histochemistry and laser-confocal microscopy, and Western blot, separately.

Results: Compared with the control group, cerebral STAT 3 immunofluorescence intensity values at the time-points of 2 h, 1 d, 3 d and 1 W, STAT 3 protein expression levels at the time-points of 2 h, 1 d and 3 d in the model group were increased significantly (P < 0.001, P < 0.05). After acupuncture intervention, cerebral STAT 3 immunofluorescence intensity values at the time-points of 1 d, 3 d, 1 W and 3 W, STAT 3 protein expression levels at the time-points of 1 d, 3 d and 3 W in the EA group were down-regulated considerably (P < 0.001, P < 0.01, P < 0.05). No significant differences were found between the control and model groups in STAT 3 immunofluorescence intensity at 3 W, and in STAT 3 protein expression levels at 1 W and 3 W, and between the EA and model groups in STAT 3 immunofluorescence intensity at 2 h, and in STAT 3 protein expression at 2 h, 3 d and 1 W (P > 0.05).

Conclusion: EA therapy can down-regulate the expression level of STAT 3 protein in the regional ischemic cerebral tissue in cerebral ischemia rats, which may contribute to its efficacy in the treatment of acute and chronic ischemic stroke.