NF-κb up-regulates spinal CX3CR1 expression in neuropathic pain rats

AIM:To study the effects of intrathecal infusion of pyrrolidine dithiocarbamate(PDTC),a nuclear factor-kappa B(NF-κB) inhibitor,on spinal CX3CR1 expression induced by sciatic chronic constriction injury(CCI) and its effects on the development of neuropathic pain in rat.METHODS:Sixty SD rats weighing 250-300 g were randomly divided into 5 groups(12 in each group):Sham+9 g/L Normal Saline(NS) group,CCI+9 g/L NS group,Sham+PDTC 1000 pmol/d group,CCI+PDTC 100 pmol/d group and CCI+PDTC 1000 pmol/d group.After implanting intrathecal catheter for 5 d,PDTC or NS was intrathecally administrated once per day.One day later,CCI or sham operation was done and pain threshold was assessed daily.Rats in each group were sacrificed at 4 d after intrathecal infusion and spinal cord lumbar intumescentia expression of CX3CR1 was assessed by Western blotting.RESULTS:The pain threshold in CCI group significantly decreased compared with that in sham group 1 to 3 d after CCI and maximally decreased at day 3 after CCI(P0.05).The pain threshold in PDTC+CCI group significantly increased compared with that in CCI group 1 to 3 d after CCI(P0.05).The expression of CX3CR1 in PDTC+CCI group significantly decreased compared with those in CCI group(P0.01).CONCLUSION:Intrathecal infusion of PDTC suppresses the spinal CX3CR1 expression and atteruates CCI-induced neuropathic pain in rats.The activated NF-κB pathway may get involved in the development of neuropathic pain through up-regulating spinal CX3CR1 expression.