Electroacupuncture Inhibiting cAMP Response Element Binding Protein DNA Binding Activity in Spinal Cord Dorsal Horn in A CFA Rat Model

Objective: To investigate whether the mechanism of electroacupuncture (EA)-induced antinociception was related to intervention in spinal cAMP response element binding protein (CREB) DNA binding activity in Complete Freund's Adjuvant (CFA)-induce inflammatory pain model. Methods: Healthy male Sprague Dawley rats were randomly divided into normal group (N group),model group (CFA group) and electroacupuncture group (EA group). Inflammatory pain model was established by injecting subcutaneously with 0. 1 mL Complete Freund's Adjuvant (CFA) into right hindpaw of rats in CFA and EA groups. EA (dilatational wave,2 /100Hz,1mA for 15 min,2mA for 15 min) was applied to bilateral Zusanli (ST 36) and Kunlun (BL 60) for 30 min at 5. 5 h after CFA injection. The paw withdrawal thresholds (PWTs) and paw volume were measured before CFA injection (as base) and at 5 h,6 h,2 d,7 d and 14 d after CFA injection. DNA of CREB binding activity in ipsilateral spinal cord dorsal horn (SCDH) was detected by electrophoretic mobility shift assay (EMSA) at 6 h,2 d and 14 d after CFA injection. Results: Compared with N group,paw of rats were obviously swollen,PWTs were decreased markedly. In CFA group,DNA of CREB binding activity was increased in spinal cord dorsal horn,at every detective time point after CFA injection. Compared with CFA group,PWTs in EA group were significantly enhanced at different time points,while,paw volume had no remarkable change. Meanwhile,DNA of CREB binding activity was less than those in CFA group at same time point. Conclusion: EA has a good analgesic effect,which may be related with EA regulating CREB DNA binding activity in spinal cord dorsal horn.