Correlation between hyperalgesia and nuclear factor-kappa B expression in spinal dorsal cord of rats with complete Freurd's adjuvant arthritis / 中国组织工程研究

ABSTRACT

BACKGROUND: Nuclear factor-kappa B (NF-κB), as a promoter of inflammatory reaction, stimulates injured parts or transcription of local inflammatory gene, promotes generation of inflammatory factors, and induces pain onset; however, the mechanism on chronic inflammatory pained spinal cord has been less reported.OBJECTIVE: To explore the NF-κB expression in spinal dorsal horn and behavioral hyperalgesia by preparing rat models of complete Freurd's adjuvant arthritis.METHODS: A total of 24 SD rats were randomly divides into sham-surgery group and complete Freund's adjuvant group, with 12 rats in each group. Adjuvant arthritis model was produced by injection of 50 pL complete Fraund's adjuvant (CFA) to the right ankle joint after anesthesia. The same volume saline was injected to the rat right ankle joint in sham-surgery group. The mechanical pain threshold, paw withdrawal thermal latency (PWTL), the diameter of ankle, and NF-kB expression in spinal dorsal horn were investigated 2 days before and 4, 7, 14, 21, and 28 days after CFA injection.thermal symptoms were not obvious. The inflamed symptoms significantly appeared on right ankle joint and developed to food to before injection and sham-surgery group, the mechanical pain threshold was significantly decreased at 4 days after CFA injection, and reached the lowest value at 21 days (P ＜ 0.01). The PWTL was significantly decreased at 4 days after CFA injection significantly increased in Ⅰ-Ⅵ in spinal dorsal horn in the complete Fraund's adjuvant group, which was higher than sham-surgery group (P ＜ 0.01). The results indicated that we could gain stable monoarthritis model by injecting CFA with oil-contained water intorat ankle joint space, and the model shown prolong and significant hyperalgesia to radial thermal and mechanical pressure;meanwhile, the NF-kB expression increased significantly in lamber Ⅰ-Ⅵ in spinal dorsal horn after the ankle joint arthritis.