Role of fibroblast growth factor-2 in neuropathic pain in rats

Objective To evaluate the role of fibroblast growth faetor-2 (FGF-2) in neuropathic pain (NP) in rats.Methods One hundred male Sprague-Dawley rats,aged 7 weeks,weighing 200-250 g,were randomly divided into 4 groups (n=25 each): sham operation group (group S),group NP,phosphate buffer solution (PBS) group and FGF-2 antibody group (group Ab).FGF-2 antibody 18 μg (40 μl) was injected intrathecally at 1,6,9,13,16 and 20 days after operation in group Ab,while the equal volume of PBS was injected intrathecally in group PBS.Spinal nerve injury was produced by exposing the sciatic nerve and its branches and ligation and transection of tibial nerve and common fibular nerve.Pain behavior was assessed at 1 day before operation and at 1,4,7,14 and 21 days after operation.The paw withdrawal mechanical threshold (PWMT) was measured.The animals were then sacrificed and the lumbar segment (L4-6) of the spinal cord was obtained for determination of the contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the spinal cord.Results Compared with group S,the PWMT was significantly decreased and the contents of TNF-α and IL-6 in the spinal cord was significantly increased in groups NP,PBS and Ab (P ＜ 0.05).The PWMT was significantly higher and the contents of TNF-α and IL-6 in the spinal cord were significantly lower in group Ab than in groups NP and PBS (P ＜ 0.05).Conclusion FGF-2 is involved in the occurrence and development of NP and induction of the inflammatory response in the rat spinal cord in involved in the mechanism. Key words: Fibroblast growth factor 2; Neuralgia