| Objective: To investigate the effects of pregabalin（PGB）on the expression of glial fibrillaryacidic protein (GFAP) and phosphorylated C-Jun N-terminal kinase(p-JNK) in the spinal dorsalhorn in rats with CCI, possible mechanisms of analgesia.Methods: All of the SD rats were randomly divided into five groups:sham operation group,chronic constriction injury group and three PGB treatment groups(P1,P2,P3). The first day afteroperation, PGB7,14and30mg/kg in2ml saline were given by intragastric infusion twice a dayfor the time. Paw withdrawal thermal latency (PWTL) were measured at day1before operationand day1,3,7and15after operation. The animals were deeply anesthetized and decapitated at day3,7,15after operation. The lumbar segment (L4～6) of the spinal cord were removed for determinati-on of GFAP and p-JNK by immunohistochemistry.Results:(1) The PWTL of five groups were compared with its preoperative PWTL,CCI,P1grouphad significant decrease (P＜0.05),P3,P2group had no significant difference on the seventh andfifteenth day after operation respectively;Compared with the S group, the PWTL of CCI,P1,P2decreased markedly(P＜0.05);Compared with CCI group,the PWTL of P1,P2,P3increasedmarkedly(P＜0.05),while the difference of P1stared at the seventh day and P2,P3started at thethird day;Compared with P1group,the PWTL had significant difference in P2,P3group.(2)Comparison with S group, the average optical density of GFAP in the spinal dorsal horn on theoperative side of CCI,P1,P2increased significantly(P＜0.05);Compared with CCI group, theexpression of GFAP decreased significantly(P＜0.05)after operation in P1,P2,P3group, while thedifference of P1started at the seventh day and P2,P3started at the third day;Compared withP1group, the average optical density of P2, P3group were significantly reduced at each timepoint(P＜0.05).(3) In comparison with S group, the average optical density of p-JNK in the spinaldorsal horn of CCI,P1increased significantly at three time point (P＜0.05),while the increase ofP2started at the third day and P3started at the seventh day;Compared with CCI group, theaverage optical density of P1decreased markedly on the seventh day, while the decrease of P2,P3started at the third day (P＜0.05);Compared with P1group,all time point of the average opticaldensity were markedly reduced in P2, P3group(P＜0.05).Conclusion: PGB may effectively alleviate the pain neuropathic pain of rats with CCI and a dose–dependent. The decrease of GFAP and p-JNK expression of in the spinal dorsal horn may be thepossible mechanisms of analgesia of PGB. |
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