Expression and function of TNF-α in dorsal root ganglion of rats with chronically compressed dorsal root ganglion

AIM: To investigate the role of TNF-α and NF-κB in the mechanism of neuropathic pain due to chronically compressed dorsal root ganglion (CCD).METHODS: Based on the CCD model, von Frey filaments were used to quantify behavior test. The expression changes of TNF-α and NF-κB were determined by Western blotting, and the correlation between the expression of TNF-α and the 50% paw withdrawal threshold was also analyzed. Moreover, the location of TNF-α in dorsal root ganglion (DRG) was observed with immunofluorescence double staining.RESULTS: We found 50% paw withdrawal threshold of CCD decreased at the first day after operation. The mechanical allodynia was the most obvious at postoperative 7~14 d and lasted longer than 35 d. The expression of TNF-α and NF-κB increased significantly in DRG after operation (P<0.01), especially at 7~14 d, and then restored gradually. Moreover, there was a correlation between the protein expression of TNF-α and the changes of neuropathic behavior (P<0.05).CONCLUSION: TNF-α and NF-κB are involved in the mechanism of mechanical allodynia after chronically compressed DRG.