神经病理性痛大鼠背根神经节TRESK mRNA表达的变化

目的 探讨神经病理性痛大鼠背根神经节(DRG) 孔钾离子通道TRESK mRNA表达的变化.方法 雄性SD大鼠32只,体重22、0～250 g,采用随机数字表法,将大鼠随机分为2组(n=16):假手术组(S组)和神经病理性痛组(NP组).采用坐骨神经分支选择性损伤法制备神经病理性痛模型.S组仅暴露神经,不结扎.于术前1 d和术后1、3、5、7、14 d取8只大鼠,测定左后肢机械缩足反应阈值(MWT)和热缩足潜伏期(TWL).于术前1 d和术后14 d痛阈测定结束后取L4,5术侧DRG,采用RT-PCR法测定TRESK mRNA的表达.结果 与S组比较,NP组MWT明显降低,DRG TRESK mRNA表达明显下调(P<0.05或0.01),TWL差异无统计学意义(P>0.05).结论 神经病理性痛大鼠DRG TRESK mRNA表达下调,该变化可能与神经病理性痛的形成有关.

Changes in TRESK mRNA expression in dorsal root ganglion in a rat model of neuropathic pain

Objective To evaluate the changes in the expression of diplopore potassium ion channel TRESK mRNA in dorsal root ganlion (DRG) in rats with neuropathic pain (NP) .Methods Thirty-two male SD rats weighing 220-250 g were randomly divided into 2 groups ( n = 16 each) : group sham operation (group S) and group NP. NP was induced by ligation and severance of left tibial and common fibular nerves according to the technique described by Decosterd. Eight rats in each group were sacrificed 1 day before and 14 day after operation and their L4,5 DRGs in the operated side were isolated for determination of TRESK mRNA expression by RT-PCR. In the remaining 8 rats in each group paw withdrawal threshold to mechanical stimuli ( MWT) and paw withdrawal latency to a thermal nociceptive stimulus (TWL) were measured at 1 day before (baseline) and 1, 3, 5, 7, 14 day after operation. Results MWT was significantly lower in group NP than in group S. The TRESK mRNA expression in L4,5 DRGs in the operated side was significantly decreased after operation as compared with the baseline before operation in group NP and was significantly lower in group NP than in group S. Conclusion The development and maintenance of NP may be closely related with down-regulation of TRESK mRNA.