Effect of intrathecal NO-711 injection on expression of Fos protein after chronic constriction injury of the sciatic nerve in rats

Objective: To observe the effect of the GAT-1 inhibitor NO-711 on behavior and c-fos expression in the dorsal horn of spinal cord after chronic constrictive injury(CCI) in rats,and to investigate the possible mechanism underlying its antinociceptive effect.Methods: Eighty four male Sprague-Dawley rats weighting 280~300 g were randomly divided into 4 groups(n=21 for each goup).All the rats were intrathecally cathetered at 5 d before sciatic nerve ligation,on the 5th day after the ligation,and NO-711or NS was injected through the intrathecal catheter.Thermal withdrawal latency(TWL) and mechanical withdrawal threshold(MWT) of rats were determined by thermal radiation apparatus and von Frey microfilament before administration and 0.5,1,2,4 and 8 h after administration,respectively.The time course of c-fos expression was assessed by immunohistochemical analysis.Results: Intrathecal administration of NO-711 significantly attenuated the activation of c-fos induced by CCI,and simultaneously ameliorated mechanical and thermal hyperalgesia induced by CCI.The effect was the strongest at 1 h,lasted over 4 h,and returned to baseline value at 8 h after administration.Conclusion: Intrathecal NO-711 injection can attenuate the mechanical and heat hyperalgesia in CCI rats through inhibition of c-fos expression in the dorsal horn of spinal cord.