目的 察鞘内注射酪氨酸激酶受体B(tyrosinekinasereceptorB,TrkB)抑制剂K252a对皮肤/肌肉切口牵拉术(skin/muscleincisionandretraction,SMIR)诱发的术后持续性痛大鼠脊髓背角钾氯共转运体-2(K+-CI—cotransporter2,KCC2)蛋白表达的影响。方法采用随机数字表法将52只成年雄性SD大鼠随机分成假手术组(对照组)、SMIR组、SMIR+-甲基亚砜(dimethylsulfoxide,DMSO)组和SMIR+K252a组,每组13只。于术前1d及术后3、7、12、22、32d测定大鼠机械缩足反射阈值(mechanicalwithdrawalthreshold,MWT),Westernblot测定术后7d大鼠脊髓背角KCC2蛋白的表达。结果与对照组比较,术后7、12、22d时MWT在sMIR组[(22.5±2.3)、(24.9±1.4)、(29.5±2.4)g]和SMIR+DMSO组[(24.0±1.9)、(24.8±2.3)、(26.7±2.1)g]明显降低(P<0.05);与SMIR组比较,术后7、12、22d时MWT在SMIR+K252a组[(31.6±1.7)、(36.1±2.0)、(38.1±2.1)g]明显上调(P〈0.05)。与对照组比较,术后7d时SMIR组和sMIR+DMS0组的脊髓背角KCC2表达明显下调(P〈0.05),SMIR+K252a组未检测到明显变化(P〉0.05)。与SMIR组比较,SMIR+K252a组的脊髓背角KCC2表达明显上调(P〈0.05)。结论脊髓背角KCC2的表达变化可能参与了大鼠术后持续性痛的形成。
Objective To observe the effects of intrathecal injections of tyrosine kinase receptor B(TrkB) inhibitor K252a on K+-Cl- cotransporter 2 (KCC2) expression in the skin/muscle incision and retraction (SMIR)-induced persistent postoperative pain in rats. Methods Fifty two aduh male SD rats were randomly and equally divided into four groups, namely the sham group(control group), SMIR group, SMIR+dimethyl sulfoxide (DMSO) group and SMIR+K252a group. Mechanical withdrawal threshold (MWT) was measured at the preoperative day 1 and postoperative days 3, 7, 12, 22 and 32, and KCC2 expression in the spinal dorsal horn was detected at postoperative day 7 by western blot. Results Compared with sham group, the MWT decreased significantly at postoperative days 7, 12, 22 in SMIR group [(22.5:1:2.3), (24.9±1.4), (29.5±2.4) g] and SMIR+DMSO group [(24.0±1.9), (24.8±2.3), (26.7±2.1) g](P〈0.05). While compared with SMIR group, the MWT increased obviously at postoperative days 7, 12, 22 in SMIR+ K252a group [(31.6±1.7), (36.1±2.0), (38.1+2.1) g](P〈0.05). In addition, at postoperative days 7, compared with sham group, the expression of KCC2 in the spinal dorsal horn decreased significantly in SMIR group and SMIR+DMSO group (P〈0.05), and no statistical significance in SMIR+K252a group (P〉0.05). Compared with SMIR group, KCC2 expression in the spinal dorsal horn in SMIR+K252a group upregulated significantly (P〈0.05). Conclusions KCC2 variations in the spinal dorsal horn may participate inthe modulation of persistent postoperative pain evoked by SMIR in rats.