阳离子-氯离子联合转运蛋白在切开模型大鼠脊髓的表达

Expression of cation-chloride cotransporters in the spinal cord of rat of incision model

目的 检测大鼠切开模型脊髓背角及背根节（dorsal root ganglion,DRG）的钠钾氯联合转运蛋白1（sodiumpotassium-chloride co-transporter 1,NKCC1）与钾氯联合转运蛋白2（potassium-chloride co-transporter 2,KCC2）的表达. 方法 30只SD大鼠用随机数字表法随机分成对照组和切开后2h、2d、3d、7d组（每组6只）,在吸入麻醉下制作切开模型或仅接受皮肤消毒.在相应时间点,在深麻醉下灌注、固定,取出L4～L5节段脊髓和双侧L5 DRG,用免疫组化方法测定NKCC1和KCC2蛋白表达. 结果 在正常大鼠,NKCC1在DRG表达,NKCC1及KCC2均在背角表达但以KCC2为主.切开后同侧DRG的NKCC1表达增加（P=0.010）,与对照组阳性细胞数（18.0±2.8）比较,2 h（40.7±2.0）、2 d（54.7±9.8）、3 d（45.3±8.6）组的阳性细胞数显著增加（P=0.026,0.001,0.008）;同侧脊髓背角NKCC1表达增加（P＜0.001）,与对照组（14.33±0.56）比较,2 h（31.00±1.32）、2d（50.33±1.80）、3 d（38.67±3.04）、7 d（32.33±0.21）组的阳性细胞数显著增加（均为P＜0.01）;同侧脊髓背角KCC2表达减少（P＜0.01）,与对照组（42.7±2.6）比较,2 h（18.0±3.5）、2 d（18.0±1.7）、3 d（23.3±1.5）、7 d（24.7±1.1）组的阳性细胞数显著减少（均为P＜0.01）. 结论 在大鼠切开模型,NKCC1在DRG及脊髓背角表达增加,KCC2在脊髓背角表达降低,提示NKCC1和KCC2参与了术后痛觉过敏形成机制,有希望成为术后疼痛治疗的新靶点.

Objective To investigate the expression of sodium-potassium-chloride co-transporter 1 （NKCC 1） and potassiumchloride co-transporter 2 （KCC2） in the spinal dorsal horn and dorsal root ganglion （DRG） of the incisional rat.Methods Adult male Sprague-Dawley rats were randomly divided into 5 groups of 6,a control and 4 incision groups at 2 h,2 d,3 d,7 d following incision.Incision was made or only skin degerming under inhalation anesthesia.At the specific time,rats were perfused with fixative under anesthesia,then the L4-L5 spinal cord and bilateral L5 DRG removed,and NKCC1 and KCC2 expression estimated by immunohistochemistry.Results In the intact rats,NKCC1 was expressed in the DRG,and both NKCC1 and KCC2 was expressed in the dorsal horn with KCC2 predominated.NKCC 1 increased in the DRG （P=0.010） following incision.Compared to controls（18.0±2.8）,the number of NKCC1-positive neurons was significantly higher in ipsilateral DRG on 2 h （40.7±2.0）,2 d （54.7±9.8）,3 d （45.3±8.6） following incision （P=0.026,0.001,0.008）.NKCC1 also increased in the ipsilateral dorsal horn （P〈0.01）,compared tocontrols （14.33±0.56）,the number of NKCC1-positive neurons was significantly higher on 2 h （31.00±1.32）,2 d （50.33± 1.80）,3 d（38.67±3.04）,7 d （32.33±0.21） and all P〈0.01.KCC2 decreased in the dorsal horn following incision （P〈0.01）.Compared to controls（42.7±2.6）,the number of KCC2-positive neurons was significantly lower in the dorsal horn on 2 h（18.0±3.5）,2 d（18.0±1.7）,3 d（23.3±1.5） and 7 d （24.7±1.1） following incision （all P〈0.01）.Conclusions NKCC1 increased in the DRG and dorsal horn while KCC2 decreased in the dorsal horn in the incision model of rat,which suggested that NKCC1 and KCC2 participated in the mechanism of hyperalgesia following incision.