The Regulation Of FGF-2in Maintaining Neuropathic Pain And The Relationship Between Astrocytes Activation And FGF-2

Part1Dynamic Alteration of Basic Fibroblast Growth FactorExpression in Rat Spinal Cord of Spared Nerve Injury ModelObjective To observe dynamic alteration of basic fibroblast growthfactor expression in rat spinal cord of spared nerve injury(SNI) model.Methods100male SD rats were randomly divided into2groups:group sham and group SNI. The paw withdrawal mechanical threshold(PWMT) was collected at1d before the operation and at1,4,7,14and28dafter the operation. Meanwhile, the expression of FGF-2, TNF-α and IL-6in the L4~6spinal cord segments of rats were measured in the same timeafter the operation.Results The PWMT began to decline at1d after SNI, peaked at7d andlasted throughout the experiment(P<0.05). The expression of FGF-2didnot significantly increase until postoperative day4, reached a peak level onpostoperative day14and lasted over the duration of the study(P<0.05). Ascompared with each postoperative time points of group Sh, the expressionof TNF-α and IL-6increased after SNI (P<0.05).Conclusion These results suggest that the up-regulation of FGF-2 contributes to maintaining neuropathic tactile allodynia associated withincrease of spinal cord inflammatory cytokines. Part2Effect of Intrathecal Anti-Fibroblast Growth Factor-2Antibodies on the Mechanical Allodynia and Activation of Spinal CordAstrocytes in a Rat Model Of Spared Nerve InjuryObjective To observe the effect of intrathecal anti-fibroblast growthfactor-2antibodies on the mechanical allodynia and activation of spinalcord astrocytes in a rat model of spared nerve injury (SNI).Methods40male SD rats were randomly divided into4groups(n=10). Group A: SNI model and intrathecal PBS; group B: SNI model andintrathecal FGF-2antibodies; group C: Sh surgery and intrathecal PBS;group D: Sh surgery and intrathecal basic fibroblast growth factor (FGF-2)antibodies. The paw withdrawal mechanical threshold (PWMT) wasevaluated at1d before the operation and at1,4,7,14and21d after theoperation. Meanwhile, the expression of FGF-2, glial fibrillary acidicprotein (GFAP) of astrocytes in the L4~6spinal cord segments of rats weregauged in the same time after the operation.Results SNI induced the mechanical allodynia and increased thenumber of FGF-2and GFAP positive cells (P<0.05). Intrathecal injection of FGF-2antibodies suppressed the increased the number of FGF-2andGFAP positive cells induced by SNI in the spinal cord, and significantlyattenuated SNI-induced mechanical allodynia(P<0.05).Conclusion FGF-2antibodies have the effect of analgesia onneuropathic pain. The activation of astrocyte in the spinal cord may beinvolved in the modulation of the neuropathic pain.