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.

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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.     

鞘内注射DREAM-shRNA对神经病理性痛大鼠脊髓背角p-CREB表达的影响

Objective To investigate the effects of intrathecal (IT) DREAM-short hairpin RNA (DREAM-shRNA) on expression of phosphorylated cyclic AMP response element binding protein (p-CREB) in the spinal dorsal horn in a rat model of neuropathic pain. Methods Adult male SD rats weighing 280-320 g were anesthetized with intraperitoneal 10% chloral hydrate. Neuropathic pain was induced by chronic constrictive injury (CCI) to sciatic nerve. IT catheters were placed according to the method described by Yaksh on 3rd day after CCI. Twenty-four rots in which IT catheter was successfully implanted were randomly divided into 4 groups (n = 6 each) : group Ⅰ sham operation (group S) ; group Ⅱ neuropathic pain (group NP) ; group Ⅲ RNA interference (group RNAi) and group Ⅳ blank vector (group BV). Lentivius with DREAM-shRNA 5 μl was injected IT in group RNAi, and blank vector 5 μl in group BV, and once a day for 7 days, starting from the day 8 after CCI. The mechanical pain threshold was measured at day 1 before CCI (T0 ,baseline) and day 7-14 after CCI (T1-8). The animals were killed on 15th day after CCI. The L4-6 lumbar segment of the spinal cord was removed for determination of the expression of green fluorescent protein (GFP) and p-CREB by immuno-fluorescent method.Results The mechanical pain threshold was significantly decreased as compared with the baseline at T0 in all 4 groups and returned to the baseline levels at T5-8 in group S and RNAi, but remained low in group NP and BY. The mechanical pain threshold was significantly lower after CCI/sham operation and significanty higher at T8 in group RNAi than in the other 3 groups. The expression of p-CREB in the spinal dorsal horn was up-regulated in group NP, RNAi and BV as compared with group S, and in group NP and BV as compared with group RNAi. The green fluorescence was observed in group RNAi but not in the other 3 groups. Conclusion IT DREAM-shRNA can ameliorate neuropathic pain in rats through inhibiting the expression of p-CREB in the spinal dorsal horn.     

拉科酰胺对神经病理性痛大鼠背根神经节Nav1.8表达的影响

目的 探讨拉科酰胺对神经病理性痛大鼠背根神经节(DRG)Nav1.8表达的影响.方法 SPF级雌性SD大鼠36只,体重120～130 g,采用随机数字表法,将其随机分为3组(n=12):假手术组(S组)、模型组(M组)、拉科酰胺组(L组).M组和L组将钢棒插入椎间孔压迫L5DRG制备神经病理性痛模型.于术前2 d、术后2,4、6、7、8、9、10 d(T0-7)时测定机械痛阈.于T4时,S组和L组腹腔注射拉科酰胺20 mg/kg(生理盐水溶解至0.5 ml),M组注射生理盐水0.5 ml,2次/d,连续4 d.每天末次给药后测定痛阈.于T7时痛阈测定后取术侧L5DRG,采用RT-PCR法和免疫组织化学法测定Nav1.8mRNA和蛋白表达水平.结果 与S组比较,M组和L组T1～7时机械痛阚降低,Nav1.8 mRNA和蛋白表达上调(P<0.05);与M组比较,L组T4～7时机械痛阈升高,Nav1.8 mRNA和蛋白表达下调(P<0.05).结论 拉科酰胺减轻大鼠慢性神经病理性痛的机制与下调损伤DRG的Nav1.8表达有关.

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Objective To investigate the effect of lacosamide on expression of Nav1 .8 in dorsal root ganglia (DRG) in a rat model of chronic neuropathic pain.Methods Thirty-six female specific-pathogen-free (SPF)SD rats were randomly assigned into 3 groups ( n = 12 each): sham operation group (group S), model group (group M) and lacosamide group (group L) . Chronic neuropathic pain was produced by insertion of a small stainless steel rod (4.00 mm in length and 0.63 mm in diameter) into the L, intervertebral foramen in the rat, producing a chronic steady compression of the DRG in M and L groups. The mechanical threshold was measured 2 days before operation and on the 2, 4, 6, 7, 8, 9 and 10 days after operation (T0-7 ) . Intraperitoneal lacosamide 20mg/kg (in normal saline 0.5 ml) was injected at T4-7, twice a day in S and L groups. In group M, normal saline 0.5 ml was injected at T4-7 twice a day and the mechanical threshold was measured after the last administration everyday . The L, DRG on the operated side was removed after measurement of pain threshold to detect the expression of Na, 1.8 mRNA and protein by RT-PCR and immuno-histochemistry respectively. Results Compared with group S, the mechanical pain threshold was significantly decreased at T1-7 and the expression of Navl .8 mRNA and protein was up-regulated in M and L groups ( P < 0.05) . Compared with group M, the mechanical pain threshold was significantly increased at T4-7 and the expression of Nav 1.8 mRNA and protein was down-regulated in group L ( P < 0.05) . Conclusion The mechanism by which lacosamide reduces chronic neuropathic pain is related to the down-regulation of the expression of Nav 1.8 in rat DRG.     

神经干细胞移植数量对大鼠神经病理性痛的影响

目的 探讨神经干细胞(NSGs)移植数量对大鼠神经病理性痛的影响.方法 取出生1～3 d的SD大鼠,制备NSCs悬液.清洁级雄性SD大鼠84只,体重150～180 g,采用右侧坐骨神经半切断法制备大鼠神经病理性痛模型.采用随机数字表法,将大鼠随机分为7组(n=12),假手术组(S组):仅暴露坐骨神经,不切断,鞘内注射细胞培养液30 μl;神经病理性痛组(NP组):于模型制备后3d鞘内注射细胞培养液30 μl;NP+NSCs 103组(N1组)、NP+NSCs 104组(N2组)、NP+NSCs 105组(N3组)、NP+NSCs 106组(N4组)和NP+NSCs 107组(N5组):于模型制备后3 d,鞘内注射相应浓度的NSCs悬液.模型制备前1 d和制备后1、3.7、14和21 d时测右足机械缩足阈值(MWT)和热缩足潜伏期(TWL);于模型制备后7和21 d,痛阈测定结束后,取右侧腰膨大脊髓背角及L5背根神经节,测定脑源性神经营养因子(BDNF)mRNA及其蛋白的表达水平.结果 与S组比较,NP组和N1～5组MWT降低,TWL缩短,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF阳性细胞数增多,染色加深;与NP组比较,N2～5组MWT升高,TWL延长,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF 阳性细胞数增多,染色加深;模型制备后7 d N1～5组MWT依次升高,TWL依次延长,脊髓背角和DRG BDNF mRNA表达依次上调(P<0.05),BDNF阳性细胞数依次增多,染色逐渐加深;模型制备后14、21d,N1～3组MWT依次升高,TWL依次延长(P<0.05),模型制备后21 d,N1～3组脊髓背角和DRG BDNF mRNA表达依次上调,BDNF阳性细胞数依次增多,染色逐渐加深;N3～5组上述指标比较差异无统计学意义(P>0.05).结论 NSCs移植减轻大鼠神经病理性痛的适宜移植数量为105个.

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Objective To investigate the effect of intrathecal (IT) transplantation of different quantities of neural stem cells (NSCs) on neuropathic pain (NP) in rats.Methods Eighty-four adult pathogen-free male SD rats weighing 150-180 g were randomly divided into 7 groups ( n = 12 each) : group sham operation (S group) , NP group, NP+ NSCs 103 , 104 , 105 , 106 , 107 groups (N1-5 groups) . NP was induced by partial transection of right sciatic nerve. NSCs were transplanted into subarachnoid space in N1-5 groups. Paw withdrawal threshold to mechanical stimulation (MWT) and paw withdrawal latency to nociceptive thermal stimuli (TWL) were measured at 1 day before (baseline) and 1, 3, 7, 14 and 21 days after operation. Brain derived neurotrophic factor ( BDNF) expression in spinal dorsal horn and dorsal root ganglia (DRG) was detected by immuno-histochemistry and RT-PCR on the 7th and 21st day after operation. Results Partial transection of the sciatic nerve gradually reduced MWT and TWL after operation starting from day 1 until day 7 and 14 as compared with the baseline in group NP. IT NSC transplantation significantly increased MWT and TWL and expression of BDNF in spinal dorsal horn and DRG in a dese-dependent manner at day 7 after operation in N1-5 groups as compared with group NP. There were no significant differences in MWT and TWL and BDNF expression among N3, N4 and N5 groups at day 21 after operation.Conclusion The proper quantity of transplanted NSCs which are able to ameliorate NP induced by partial transection of sciatic nerve in rats is 105 .     

神经病理性痛大鼠内侧额叶前皮质GABAAα1受体表达的变化

目的 评价神经病理性痛大鼠内侧额叶前皮质γ-氨基丁酸Aα1亚型(GABAAα1)受体表达的变化.方法 成年雄性Wistar大鼠9只,体重200～210 g,采用随机数字表法,将其随机分为3组(n=3):对照组(C组)、假手术组(s组)和神经病理性痛组(P组).P组采用坐骨神经慢性压迫法制备大鼠神经病理性痛模型;S组只暴露坐骨神经,而不结扎.于术前1 d和术后1、4、7、10、14 d时,测定机械痛阈和热痛阈.痛阈测定结束后,处死大鼠,取内侧额叶前皮质,采用Western blot法检测GABAAα1受体的表达.结果 与C组和S组比较,P组术后各时点机械痛阈和热痛阈降低,内侧额叶前皮质GABAAα1受体表达上调(P＜0.01);C组和S组间机械痛阈、热痛阈和内侧额叶前皮质GABAAα1受体表达比较差异无统计学意义(P＞0.05).结论 内侧额叶前皮质GABAAα1受体表达上调可能参与了大鼠神经病理性痛的形成与维持.

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Objective To investigate the changes in the expression of GABAAα1, receptors in medial prefrontal cortex (mPFC) in a rat model of neuropathic pain. Methods Nine male Wistar rats weighing 200-210 g were randomly divided into 3 groups ( n = 3 each): control group (group C) , sham operation group (group S) and neuropathic pain group (group P). Neuropathic pain was induced by chronic constrictive injury. The right sciatic nerve was exposed and 4 loose ligatures were placed on the sciatic nerve at 1 mm intervals with 3-0 chromic catgut. In group S, the right sciatic nerve was exposed but not ligated. The thermal and mechanical pain threshold was measured at 1 d before and 1,4,7, 10 and 14 d after operation. The animals were then sacrificed and the mPFC was removed. The expression of GABAAα1, receptors in mPFC was determined by Western blot. Results Compared with C and S groups, thermal and mechanical pain threshold were significantly decreased and the expression of GABAAα1, receptors was up-regulated in group P ( P ＜ 0.01) . There was no significant difference was in the thermal and mechanical pain threshold and expression of GABAAα1 receptors between C and S groups (P ＞ 0.05). Conclusion Up-regulation of GABAAα1 receptor expression in mPFC may be involved in the development and maintenance of neuropathic pain in rats.     

环氧化酶在神经病理性痛大鼠背根神经节P2X3受体表达上调中的作用

目的 探讨环氧化酶(COXs)在神经病理性痛大鼠背根神经节P2X3受体表达上调中的作用.方法 雄性SD大鼠24只,体重250～280g,采用随机数字表法,将其随机分为4组(n=6),神经病理性痛组(CCI组)、COX-1抑制剂组(Ⅰ组)和COX-2抑制剂组(C组)制备坐骨神经慢性缩窄性损伤(CCI)模型,假手术组(S组)仅暴露坐骨神经.于术后3～14 d Ⅰ组和C组分别以COX-1抑制剂布洛芬40mg·kg-1·d-1和COX-2抑制剂塞来昔布30mg·kg-1·d-1灌胃.分别于术前(基础状态)、术后3、5、7、10、14 d时测定热缩足潜伏期(PWL)和机械缩足阈值(PWT).然后处死大鼠,取L()-6节段背根神经节,测定P2X3受体mRNA及其蛋白表达水平.结果 与S组比较,CCI组术后PWL缩短,PWT降低,P2X3受体mRNA及其蛋白表达上调(P＜0.05);与CCI组比较,I组和C组术后PWL延长,PWT升高,P2X3受体mRNA及其蛋白表达下调(P＜0.05);与I组比较,C组术后PWL延长,PWT升高,背根神经节P2X3受体mRNA及其蛋白表达上调(P＜0.05).结论 COXs参与了神经病理性痛大鼠背根神经节P2X3受体表达上调,且COX-1的作用强于COX-2.

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Objective To investigate the role of cyclooxygenases (COXs) in the up-regulation of the expression of P2X3 receptors in the dorsal root ganglion (DRG) in rats with neuropsthic pain. Methods Twenty-four male SD rats, weighing 250-280 g, were randomly divided into 4 groups ( n = 6 each): sham operation group (group S), chronic constrictive injury (CCI) group, COX-1 inhibitor ibuprofen group (group Ⅰ), and COX-2 inhibitor celecoxib group (group C). Neuropathic pain was induced by CCI. The animals were anesthetized with intraperitoneal 10% chloral hydrate 300-500 mg/kg. CCI was produced by placing 4 ligatures on the left sciatic nerve at 1 mm intervals. In group S, the left sciatic nerve was only exposed but not ligated. In groups Ⅰ and C, ibuprofen 40 mg·kg-1 ·d-1 and celecoxib 30 mg·kg-1 ·d-1 were given through a gastric tube into the stomach at day 3-14 after operation respectively. Paw withdrawal latency (PWL) and paw withdrawal threshold (PWT) were measured before operation (baseline), and at 3, 5, 7, 10 and 14 days after operation. Then the rats were sacrificed and their L()-6 DRGs were removed to detect the expression of P2X3 mRNA and protein. Results Compared with group S, PWL was significantly shortened, PWT decreased, and P2X3 mRNA and protein expression up-regulated in group CCI ( P ＜ 0.05＝. Compared with group CCI, PWL was significantly prolonged, PWT increased, and P2X3 mRNA and protein expression down-regulated in groups Ⅰ and C (P ＜0.05＝. Compared with group Ⅰ, PWL was significantly prolonged, PWT increased, and P2X3 mRNA and protein expression up-regulated in group C ( P ＜0.05＝. Conclusion COXs are involved in the up-regulation of the expression of P2X3 receptors in the DRG in rats with neuropathic pain, and the effect of COX-1 is stronger than that of COX-2.     

神经病理性痛大鼠背根神经节神经元γ氨基丁酸激活电流的改变

目的 探讨神经病理性痛大鼠背根神经节(DRG)神经元γ氨基丁酸(GABA)激活电流的改变.方法 健康成年SD大鼠20只,雌雄不拘,体重100～150g,采用随机数字表法,将大鼠随机分为2组,假手术组(S组,n=5),神经病理性痛组(NP组,n=15)行l3脊神经结扎诱发神经病理性痛.于术后5 d处死大鼠,S组急性分离L3-5DRG神经元,NP组急性分离L5DRG神经元,建立膜片钳全细胞记录模式.通过细胞外加药排管给予GABA 100μmol/L,记录各类型DRG神经元中GABA激活电流的发生率及电流幅度,记录给GABA前、后静息电位、动作电位(基强度、阈电位和超射值).结果 细胞外给予100μmol/L的GABA后可诱发部分神经元出现快速失活的内向电流.与给GABA前比较,S组给GABA后DRG大、中神经元出现明显去极化,静息电位升高,超射值和基强度降低(P＜0.05),阈电位差异无统计学意义(P＞0.05),NP组给GABA后DRG大、中神经元静息电位升高(P＜0.05),超射值、基强度和阈电位差异无统计学意义(P＞0.05).与S组比较,NP组DRG大、中神经元GABA激活电流的发生率和电流幅度均降低,静息电位、超射值、基强度的变化幅度降低(P＜0.05),阈电位的变化幅度差异无统计学意义(P＞0.05).S组和NP组部分DRG小神经元出现自发放电,具有自发放电的神经元上没有GABA激活电流出现.结论 神经病理性痛大鼠DRG大、中神经元上GABA介导的抑制信号的减弱,引起神经元兴奋性升高,可能是神经病理性痛的发病机制之一.

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Objective To investigate the change in GABA receptor-activated current in dorsal root ganglion (DRG) neurons in rats with neuropathic pain. Methods Twenty adult SD rats of both sexes weighing 100-150 g were randomly divided into 2 gorups: sham operation group (group S, n = 5) and neuropathic pain group (group NP, n= 15). Neuropathic pain was induced by ligation of right L5 spinal nerve. The animals were sacrificed at 5 days after operation. The L5 DRG( neurons in group NP and L3-5 DRG neurons in group S were immediately isolated. Whole-cellpatch- clamp technique was used. The extracellular solution contained GABA 100μmol/L.The frequency and amplitude of the GABA-activated current in DRG neurons and the changes in action potential (threshold potential, rheobase and overshoot) and resting potential before and after GABA administration were recorded. Results GABA 100μmol/L induced rapid inactivation of inward current in most neurons. Compared with the baseline before application of GABA, in group S GABA induced depolarization,increased resting potential and decreased amplitude and rheobase of action potential in large and medium DRG neurons, while in group NP GABA increased resting potential but induced no significant change in threshold potential and rheobase and overshoot of action potential. The frequency and amplitude of GABA-activated current and the degree of change in resting potential and rheobase and overshoot of action potential were significantly lower in group NP than in group S.Spontaneous discharge occurred in small DRG neurons in both groups. No GABA-activated current was observed in all DRG neurons with spontaneous discharge. Conclusions Neuropathic pain is induced by decreasing GABA-mediated inhibition signals in large and medium DRG neurons leading to increased excitability of neurons.     

加巴喷丁对奥沙利铂诱发神经病理性痛小鼠背根神经节神经元高电压激活钙通道的影响

目的 评价加巴喷丁对奥沙利铂诱发神经病理性痛小鼠背根神经节(DRG)神经元高电压激活钙通道的影响.方法 清洁级雄性昆明小鼠,体重20～25 g,6周龄.采用腹腔注射奥沙利铂3mg/kg的方法制备神经病理性痛模型.取模型制备成功的小鼠41只,采用随机数字表法,将小鼠随机分为神经病理性痛组(NP组,n=20)和加巴喷丁组(G组,n=21),另取10只正常小鼠为正常对照组(C组).G组于奥沙利铂给药后第3天腹腔注射加巴喷丁100mg/kg,NP组及C组给予等容量的生理盐水,每天1次,连续3 d.于加巴喷丁给药前即刻、给药后1～3 d(T1-4)时测定小鼠双后肢机械缩足阈值(MWT).于最后一次MWT测定后,取两侧L4,5节段DRG,分离DRG神经元,采用全细胞膜片钳记录峰电流密度,拟合DRG神经元高电压激活钙通道激活曲线和稳态失活曲线,计算半数激活电位(Va1/2)和半数失活电位(Vi1/2).结果 与C组比较,NP组T1～4时、G组T1时MWT降低,NP组峰电流密度和Vi1/2升高(P＜0.05),Va1/2差异无统计学意义,G组峰电流密度、Vi1/2和Va1/2差异无统计学意义(P＞0.05);与NP组比较,G组T2-4时MWT升高,峰电流密度和Vi1/2降低(P＜0.05).结论 加巴喷丁减轻小鼠奥沙利铂诱发神经病理性痛的机制可能与抑制DRG神经元高电压激活钙通道电流,促进通道失活有关.

Abstract：

Objective To investigate the effects of gabapentin on high-voltage-activated calcium currents in dorsal root ganglion (DRG) neurons in mice with oxaliplatin-induced neuropathic pain (NP). Methods Pathogen-free male Kunming mice aged 6 weeks weighing 20-25 g were used in this study. NP was induced by injection of intraperitoneal oxaliplatin 3 mg/kg. Successful induction of NP was defined as the mechanical paw withdrawal threshold (MWT) measured at 3 d after oxaliplatin administration decreased to 40% of the baseline ( before administration of oxaliplatin). Forty-one mice in which NP was successfully induced were randomly divided into 2 groups: NP group ( n = 20) and gabapentin group (group G, n = 21 ). Another 10 normal mice served as control group (group C). At 3 days after oxaliplatin administration, gabapentin 100 mg/kg was injected intraperitoneally once a day for 3 consecutive days in group G, while C and NP groups received the equal volume of normal saline.MWT to von Fray filament stimulation was measured immediately before and 1-3 days after gabapentin administration (T1-4). After the last measurement of MWT, bilateral L4.5 DRG was collected and neurons were isolated. The high-voltage-activated calcium currents were recorded using whole-cell patch-clamp technique. The peak current density and the voltage where half of the current was activated ( Va1/2 ) or inactivated ( Vi 1/2 ) were calculated. Results Compared with group C, MWT at T1-4 was decreased, the peak current density and Vi1/2 were significantly increased in group NP, and MWT at T1 was decreased in group G ( P ＜ 0.05). There was no significant difference in the peak current density, Vi1/2 and Va1/2 between C and G groups ( P ＞ 0.05). MWT at T2-4 was significantly increased, while the peak current density and Vi1/2 were significantly decreased in group G compared with group NP (P ＜ 0.05). Conclusion Gabapentin can reduce oxaliplatin-induced NP in mice through inhibiting high-voltage-activated calcium currents and promoting the inactivation of the channels in DRG neurons.     

The role of N--methy--D--aspartate receptor subunit NR2B in the spinal cord in cancer pain

Cancer pain is one kind of the most common and severe chronic pain. The mechanisms and therapeutics of cancer pain have not achieved a breakthrough yet. Based on the well established involvement of NMDA （N-methy-d-aspartate） receptor containing NR2B in inflammatory pain and neuropathic pain and the effective pain relief by ketamine in cancer patients with intractable pain, we supposed that NR2B in the spinal cord was an important factor in cancer pain. In this study, the possible role played by NR2B in the spinal cord was investigated in mouse model of bone cancer pain. Osteosarcoma NCTC 2472 cells were implanted into the intramedullary space of the right femurs of mice to induce ongoing bone cancer related pain behaviors. At day 14 after operation, the expression of NR2B mRNA and NR2B protein in the spinal cord were higher in tumor-bearing mice compared to the sham mice. Intrathecal administration of 5 and 10 pg of NR2B subunit-specific NMDA receptor antagonist, ifenprodil attenuated cancer-evoked spontaneous pain, thermal hyperalgesia and mechanical allodynia. These results suggest that NR2B in the spinal cord may participate in bone cancer pain of mice, and ifenprodil may be a useful alternative or adjunct therapy for controlling bone cancer pain. The findings may lead to novel strategies for the treatment of bone cancer pain.     

CB2受体激动剂JWH015对大鼠神经病理性疼痛的治疗作用

Objective To test whether activation of CB2 receptor would induce antinociception and investigate the role of in-trathecal JWH015 in the modulation of Tyr-1472 phosphorylation of the spinal NR2B subunit in a model of neuropathic pain. Meth-otis 84 male SD rats with intrathecal catheter insertion were randomly divided into 3 groups: sham + 50% DMSO group (Sham group); CCD + 50%DMSO group(Vehicle group); CCD+JWH015 group(JWH015 group). Seven days after Sham or CCD(without in-trathecal injection), the lumbosacral spinal cords of 6 Sham rats and 6 CCD rats were collected for immunohistochemical study to de-termine the spinal expression of Tyr-1472 phosphorylated NR2B subunit(baseline). The rest were intrathcally injected with 50%DMSO 10 μl or JWH015 10 μg seven days after Sham or CCD. For behavioral studies, the data of paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured in Sham group or CCD group, before intrathecal injection and 1, 2, 4, 8, 24, 72 h after intrathecal injection (n=6). For immunohistochemical study, the lumbosacral spinal cords were collected 4, 8, 24, 72 h after intrathecal injection(n=6). Results Compared with the baseline before operation, the PWMT and the PWTL of Vehicle group and JWHOI5 group began to decrease before intrathecal injection(P<0.01). Compared with Vehicle group, PWMT and PWTL of JWH015 group increased markedly 1, 2 and 4 h after intrathecal injection (P0.05). Tyr-1472 phosphorylated NR2B subunit expression in the superficial dorsal horn was weak in all sham groups, but increased significantly 7 days after CCD. While intrathecal 50%DMSO did not decrease the expres-sion of Tyr-1472 phosphorylated NR2B subunit in the superficial dorsal horn, the expression of Tyr-1472 phosphorylated NR2B sub-unit in the superficial dorsal horn decreased obviously 4 h and 8 h after intrathcal JWH015. However, the expression of Tyr-1472 phosphorylated NR2B subunit in the superficial dorsal horn increased again 24 h and 72 h after intrathcal JWH015. Conclusion In-trathecal administration of CB2 receptor agonist JWHOI5 may provide analgesic effect, which is probably attributed to the decrease in the spinal expression of Tyr-1472 phosphorylated NR2B subunit.     

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.     

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.     

神经病理性痛大鼠鞘内注射人前脑啡肽原基因修饰骨髓间充质干细胞的镇痛效果

目的 探讨神经病理性痛大鼠鞘内注射人前脑啡肽原(PENK)基因修饰人骨髓间充质干细胞(hMSC)的镇痛效果.方法 取鞘内置管成功的健康雄性SD大鼠40只,周龄6～8周,体重160～180 g,随机分为4组(n=10),A组为正常对照组;B组、C组和D组采用坐骨神经慢性压迫性损伤(CCI)法建立神经病理性痛模型,于CCI术后3 d鞘内给药,A组和B组鞘内注射生理盐水10μl;C组鞘内注射转染空载体的hMSC细胞(hMSC-pBABE)悬液10μl(2×108～3×108/μl);D组鞘内注射hMSC-PENK细胞悬μl液10μl(2×108～3×108个/μl).于术前、术后3、5、7、9、14 d时测定热痛阈.术后14 d痛阈测定后取新鲜脊髓组织,采用RT-PCR法测定PENK mRNA表达.结果 与术前比较,B组、C组、D组术后各时点热痛阈降低(P＜0.05).与A组比较,B组、C组、D组热痛阈降低,B组和C组PENK mRNA表达下调,D组PENK mRNA表达上调(P＜0.05).与B组和C组比较,D组热痛阈升高,PENK mRNA表达上调(P＜0.05).B组和C组各指标比较差异无统计学意义(P＞0.05).结论 大鼠鞘内注射PENK基因修饰的hMSC可减轻神经病理性痛.     

rAd5/NR2B镇痛疫苗对神经病理性痛大鼠认知功能的影响

目的 评价N-甲基-D天冬氨酸受体2B亚基(NR2B)基因重组腺病毒(rAd5/NR2B)对神经病理性痛大鼠认知功能的影响.方法 雌性SD大鼠40只,体重180～200 g,随机分为4组(n=10):对照组(C组)、rAd5/NR2B镇痛免疫组(rAd5/NR2B组)、神经病理性痛组(SP组)和rAd5/NR2B镇痛疫苗+神经病理性痛组(rAd5/NR2B+SP组).C组和rAd5/NR2B组分别胃内灌注生理盐水0.1 ml和rAd5/NR2B镇痛疫苗1×10~8 PFU,2周后重复灌注.SP组制备神经病理性痛模型,1周后腹腔注射生理盐水0.1 ml.rAd5/NR2B+SP组胃内灌注rAd5/NR2B镇痛疫苗1×10~8 PFU,2周后重复灌注,再1周后制备神经病理性痛模型.测定大鼠机械缩爪阈值(MWT).行Morris水迷宫实验测定大鼠认知功能,记录潜伏期和游泳速度.采用免疫组织化学法检测大鼠海马NR2B的表达水平.结果 (1)与C组比较,rAd5/NR2B组MWT差异无统计学意义(P＞0.05),SP组和rAd5/NR2B+SP组MWT降低(P＜0.05);与SP组比较,rAd5/NR2B+SP组MWT升高(P＜0.05).(2)各组游泳速度比较差异无统计学意义(P＞0.05);与C组比较,rAd5/NR2B组潜伏期差异无统计学意义(P＞0.05),SP组和rAd5/NR2B+SP组潜伏期延长(P＜0.05);与SP组比较,rAd5/NR2B+SP组潜伏期差异无统计学意义(P＞0.05).(3)与C组比较,rAd5/NR2B组和rAd5/NR2B+SP组海马NR2B表达差异无统计学意义(P＞0.05),SP组海马NR2B表达上调(P＜0.05);与SP组比较,rAd5/NR2B+SP组海马NR2B表达下调(P＜0.05).结论 rAd5/NR2B疼痛疫苗对神经病理性痛大鼠认知功能无明显影响.     

脊髓1型多聚ADP核糖聚合酶在大鼠神经病理性痛中的作用

目的 评价脊髓1型多聚ADP核糖聚合酶(PARP1)在大鼠神经病理性痛中的作用.方法 雄性成年Wistar大鼠180只,体重180～220 g,采用随机数字表法,将其随机分为4组(n=45):假手术组(S组)、神经病理性痛组(NP组)、小干扰RNA(siRNA)阴性对照(NC-siRNA)组(NS组)和PARP1-siRNA组(PS组).NP组、PS组和NS组采用结扎L5脊神经的方法制备大鼠神经病理性痛模型.S组仅暴露L5脊神经,但不结扎.PS组和NS组术后鞘内注射PARP1-siRNA慢病毒和NC-siRNA慢病毒10μl.于术后3、7和14 d时测定机械痛阈,然后处死大鼠,取脊髓组织,采用免疫荧光法检测PARP1和胶质纤维酸性蛋白( GFAP)的共表达情况,采用Western blot法测定PARP1和GFAP的蛋白表达,采用RT-PCR法测定PARP1和GFAP的mRNA表达.结果 与S组比较,NP组、NS组和PS组术后各时点机械痛阈下降,脊髓PARP1和GAFP的蛋白及其mRNA表达上调(P＜0.05).与NP组和NS组比较,PS组术后各时点机械痛阈升高,脊髓PARP1和GAFP蛋白及其mRNA表达下调(P＜0.05).NP组和NS组间上述各指标比较差异无统计学意义(P＞0.05).PARG1在脊髓星形胶质细胞存在表达.结论脊髓PARP1通过激活星形胶质细胞参与了大鼠神经病理性痛的形成与维持.     

NR2B在神经病理性痛大鼠海马突触长时程增强易化中的作用

目的 评价含2B亚基的N-甲基-D-天冬氨酸受体(NR2B)在神经病理性痛大鼠海马突触长时程增强(LTP)易化中的作用.方法 成年雄性Wistar大鼠24只,体重180～230 g,随机分为4组(n=6):假手术组(S组),假手术+Ro25-6981组(SR组)、神经病理性痛组(NP组)和神经病理性痛+Ro25-6981组(NR组).采用结扎L4,5左侧脊神经的方法制备大鼠神经病理性痛模型.于模型制备后7、14和21 d时观察大鼠痛行为学及足部形态;于模型制备前(基础状态)、制备后7,14和21 d时测定痛阈;于最后一次痛阈测定结束后3 d记录海马CAI区兴奋性突触后电位(EPSP),以高频刺激(HFS)诱发LTP,SR组和NR组于HFS前20 min经侧脑室输注Ro25-6981(NR2B特异性阻断剂)6 μl(2.3 μg),速率1μl/min.LTP为HFS后EPSP峰值较基础值增大10%以上且维持时间≥10 min,并行LTP分级,以评价其程度.结果 与S组和SR组比较,NP组和NR组各时点痛阈降低,NP组LTP程度升高(P<0.05),NR组LTP程度差异无统计学意义(P>0.05);NR组LTP程度组低于NP组(P<0.05).结论 神经病理性痛大鼠海马突触LTP的易化可能与NR2B的激活有关.     

神经干细胞移植数量对大鼠神经病理性痛的影响

目的 探讨神经干细胞(NSGs)移植数量对大鼠神经病理性痛的影响.方法 取出生1～3 d的SD大鼠,制备NSCs悬液.清洁级雄性SD大鼠84只,体重150～180 g,采用右侧坐骨神经半切断法制备大鼠神经病理性痛模型.采用随机数字表法,将大鼠随机分为7组(n=12),假手术组(S组):仅暴露坐骨神经,不切断,鞘内注射细胞培养液30 μl;神经病理性痛组(NP组):于模型制备后3d鞘内注射细胞培养液30 μl;NP+NSCs 103组(N1组)、NP+NSCs 104组(N2组)、NP+NSCs 105组(N3组)、NP+NSCs 106组(N4组)和NP+NSCs 107组(N5组):于模型制备后3 d,鞘内注射相应浓度的NSCs悬液.模型制备前1 d和制备后1、3.7、14和21 d时测右足机械缩足阈值(MWT)和热缩足潜伏期(TWL);于模型制备后7和21 d,痛阈测定结束后,取右侧腰膨大脊髓背角及L5背根神经节,测定脑源性神经营养因子(BDNF)mRNA及其蛋白的表达水平.结果 与S组比较,NP组和N1～5组MWT降低,TWL缩短,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF阳性细胞数增多,染色加深;与NP组比较,N2～5组MWT升高,TWL延长,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF 阳性细胞数增多,染色加深;模型制备后7 d N1～5组MWT依次升高,TWL依次延长,脊髓背角和DRG BDNF mRNA表达依次上调(P<0.05),BDNF阳性细胞数依次增多,染色逐渐加深;模型制备后14、21d,N1～3组MWT依次升高,TWL依次延长(P<0.05),模型制备后21 d,N1～3组脊髓背角和DRG BDNF mRNA表达依次上调,BDNF阳性细胞数依次增多,染色逐渐加深;N3～5组上述指标比较差异无统计学意义(P>0.05).结论 NSCs移植减轻大鼠神经病理性痛的适宜移植数量为105个.     

神经干细胞移植数量对大鼠神经病理性痛的影响

目的 探讨神经干细胞(NSGs)移植数量对大鼠神经病理性痛的影响.方法 取出生1～3 d的SD大鼠,制备NSCs悬液.清洁级雄性SD大鼠84只,体重150～180 g,采用右侧坐骨神经半切断法制备大鼠神经病理性痛模型.采用随机数字表法,将大鼠随机分为7组(n=12),假手术组(S组):仅暴露坐骨神经,不切断,鞘内注射细胞培养液30 μl;神经病理性痛组(NP组):于模型制备后3d鞘内注射细胞培养液30 μl;NP+NSCs 103组(N1组)、NP+NSCs 104组(N2组)、NP+NSCs 105组(N3组)、NP+NSCs 106组(N4组)和NP+NSCs 107组(N5组):于模型制备后3 d,鞘内注射相应浓度的NSCs悬液.模型制备前1 d和制备后1、3.7、14和21 d时测右足机械缩足阈值(MWT)和热缩足潜伏期(TWL);于模型制备后7和21 d,痛阈测定结束后,取右侧腰膨大脊髓背角及L5背根神经节,测定脑源性神经营养因子(BDNF)mRNA及其蛋白的表达水平.结果 与S组比较,NP组和N1～5组MWT降低,TWL缩短,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF阳性细胞数增多,染色加深;与NP组比较,N2～5组MWT升高,TWL延长,脊髓背角和DRG BDNF mRNA表达上调(P<0.05),BDNF 阳性细胞数增多,染色加深;模型制备后7 d N1～5组MWT依次升高,TWL依次延长,脊髓背角和DRG BDNF mRNA表达依次上调(P<0.05),BDNF阳性细胞数依次增多,染色逐渐加深;模型制备后14、21d,N1～3组MWT依次升高,TWL依次延长(P<0.05),模型制备后21 d,N1～3组脊髓背角和DRG BDNF mRNA表达依次上调,BDNF阳性细胞数依次增多,染色逐渐加深;N3～5组上述指标比较差异无统计学意义(P>0.05).结论 NSCs移植减轻大鼠神经病理性痛的适宜移植数量为105个.