CAJ | 학술논문

目的探讨脊髓神经元型一氧化氮合酶(nNOS)在大鼠神经病理性痛中的作用.方法健康雄性SD大鼠40只,体重220～280 g,采用结扎坐骨神经干的方法建立坐骨神经慢性压迫性损伤(CCI)模型.随机分为4组(n=10),Ⅰ组及Ⅱ组暴露坐骨神经干,分别于术后1 d开始鞘内注射选择性nNOS抑制剂7-NI 60 μg[溶于20%二甲基亚砜(DMSO)]10μl)、20%DMSO 10μl,1次/d,连续6d;Ⅲ组及Ⅳ组制备CCI模型,分别于术后1 d开始鞘内注射7-NI 60μg(溶于20%DMSO 10μl)、20%DMSO 10 μl,1次/d,连续6 d.分别于CCI前1 d、CCI后1、3、5、7 d时测定大鼠机械痛阈和热痛阈.于CCI后7 d,各组分别取5只大鼠,取术侧L_(4～6)背根神经节,分别采用实时定量PCR和Western blot法测定nNOS mRNA及蛋白的表达水平.结果与Ⅰ组和Ⅱ组比较,T_(1～4)时Ⅲ组和Ⅳ组术侧后肢机械痛阈和热痛阈降低(P＜0.05),背根神经节nNOS蛋白及mRNA的表达上调(P＜0.05);与Ⅲ组比较,T_(1～4)时Ⅳ组机械痛阈和热痛阈降低,背根神经节nNOS蛋白及mRNA的表达上调(P＜0.05).结论脊髓nNOS参与了大鼠神经病理性痛的形成.
목적 탐토척수신경원형일양화담합매(nNOS)재대서신경병이성통중적작용.방법 건강웅성SD대서40지,체중220～280 g,채용결찰좌골신경간적방법건립좌골신경만성압박성손상(CCI)모형.수궤분위4조(n=10),Ⅰ조급Ⅱ조폭로좌골신경간,분별우술후1 d개시초내주사선택성nNOS억제제7-NI 60 μg[용우20%이갑기아풍(DMSO)]10μl)、20%DMSO 10μl,1차/d,련속6d;Ⅲ조급Ⅳ조제비CCI모형,분별우술후1 d개시초내주사7-NI 60μg(용우20%DMSO 10μl)、20%DMSO 10 μl,1차/d,련속6 d.분별우CCI전1 d、CCI후1、3、5、7 d시측정대서궤계통역화열통역.우CCI후7 d,각조분별취5지대서,취술측L_(4～6)배근신경절,분별채용실시정량PCR화Western blot법측정nNOS mRNA급단백적표체수평.결과 여Ⅰ조화Ⅱ조비교,T_(1～4)시Ⅲ조화Ⅳ조술측후지궤계통역화열통역강저(P＜0.05),배근신경절nNOS단백급mRNA적표체상조(P＜0.05);여Ⅲ조비교,T_(1～4)시Ⅳ조궤계통역화열통역강저,배근신경절nNOS단백급mRNA적표체상조(P＜0.05).결론 척수nNOS삼여료대서신경병이성통적형성.
Objective To investigate the role of spinal neuronal nitric oxide synthase(nNOS)in neuropathic pain in rats.Methods Male SD rots weighing 220-280 g were used in this study.The rats were implanted with chronic intrathecal(IT)catheters.Forty rats with normal motor function were randomly divided into4 groups(n = 10 each): group Ⅰ sham operation+7-nitorindaxole(7-NI);group Ⅱ sham operation+DMSO;group Ⅲ CCI+7-NI and group Ⅳ CCI+DMSO.Neuropathic pain was induced by chronic constrictive injury(CCI).Right sciatic nerve was exposed and 4 ligatures were placed on the sciatic nerve at 1 mm intervals with 4-0chromic catgut.In sham operation groups right sciatic nerve was exposed but not ligated.In group Ⅰ and Ⅲ 7-NI(a selective nNOS inhibitor)60 μg in 20% DMSO 10 μl was injected IT once a day for 6 consecutive days while in group Ⅱ and Ⅳ only the solvent 20% DMSO 10 μl was injected IT instead of 7-NI.Paw withdrawal threshold(PWT)to mechanical stimulation with von Frey filaments and paw withdrawal latency(PWL)to radiant beat were measured before operation(baseline)and at 1,3,5,7 d after operation.Five animals in each group were killed on the 7th day after operation after last pain threshold measurement.The dorsal root ganglions(DRGs)of the lumbar segment(L_(4-6))were removed for determination of the expression of nNOS mRNA(by RT-PCR)and protein(by Western blot).Results CCI significantly decreased the mechanical and thermal pain thresholds and increased the expression of nNOS mRNA and protein in the ipsilateral DRGs.IT 7-NI administration significantly suppressed the expression of nNOS in the lumbar DRGs and significantly attenuated CCI-induced mechanical allodynia and thermal hyperalgesia.Conclusion The spinal nNOS is involved in the formation of neuropathic pain.