人参皂甙-Rd对SNI大鼠痛敏异常及孤束核内P物质和NK-1受体表达的影响

目的:通过观察人参皂甙-Rd(G-Rd)对坐骨神经分支选择损伤(spared nerve injure,SNI)大鼠痛敏异常及延髓内脏带孤束核内P物质(substance P,SP)和NK-1受体表达的影响,探讨G-Rd的镇痛机制。方法:成年雄性SD大鼠30只,随机分为五组:空白对照组(blank control)、假手术组(sham operation)、SNI组、SNI+saline组(腹腔注射,i.p.)、SNI+G-Rd组(i.p.)。行为学检测应用von Frey纤维测定上述各组大鼠手术侧后肢机械缩足反射阈值(paw withdrawal mechanical thresholds,PWMT);用免疫荧光组织化学染色法,在激光扫描共聚焦显微镜下,对比检测上述各组间孤束核(NTS)内SP样免疫阳性产物和NK-1样免疫阳性产物的平均荧光强度(mean flu-orescent intensity,MFI)。结果:SNI模型组术后10 d,手术侧后肢的PWMT值(4.63 g)明显低于正常对照组和假手术组(18.20～20.30 g),术后20 d达到最低阈值(2.38 g);而SNI+G-Rd组的PWMT值(4.67 g)则明显高于SNI组和SNI+saline组(P<0.05)。免疫荧光染色结果显示:术后20 d时,SNI组NTS内SP样和NK-1样免疫荧光的平均强度明显高于空白对照组和假手术组(P<0.05);但SNI+G-Rd组的SP样和NK-1样免疫荧光的平均强度则明显低于SNI组和SNI+saline组(P<0.05)。结论:人参皂甙-Rd可以明显改善SNI引起的痛敏异常,其机制之一可能与其有效减少NTS内SP和NK-1受体的表达有密切关系。     

人参皂甙-Rd对SNI大鼠痛敏异常及脊髓背角内P物质和NK-1受体表达的影响

目的:观察人参皂甙-Rd(Ginsenoside-Rd,G-Rd)对坐骨神经分支选择损伤(spared nerve injury,SNI)大鼠痛敏异常及脊髓背角内P物质(substance P,SP)和NK-1受体表达的影响,进而探讨G-Rd镇痛的脊髓机制.方法:成年雄性SD大鼠(30只)随机分成五组:空白对照组(bl...     

神经病理性痛大鼠脊髓背角缝隙连接蛋白表达变化及鞘内注射甘珀酸的镇痛作用

目的 研究慢性神经病理性痛大鼠脊髓背角内缝隙连接蛋白家族(Cx)中Cx43和Cx32的表达变化,以及鞘内注射缝隙连接阻断剂甘珀酸（CBX）的镇痛作用。 方法 成年SD大鼠50只,分为正常对照组、假手术组和坐骨神经分支选择性损伤组(SNI)。手术前1d、术后3d、5d、10d、20d和30d,观察大鼠行为并检测机械刺激缩足反射阈值(PWMT)。15只大鼠于术后10d、20d、30d取脊髓腰段进行免疫印迹检测,另15只大鼠于术后10d、20d、30d取脊髓腰段进行免疫荧光染色,检测腰段脊髓背角内Cx43和Cx32表达的变化。有10只大鼠先进行鞘内插管,后行SNI手术,术后20d向鞘内注射生理盐水或CBX,观察大鼠PWMT的变化。 结果 SNI大鼠手术侧PWMT阈值较非手术侧或假手术组明显降低,术后20d达最低值。SNI大鼠手术侧脊髓背角内Cx43、32表达增多,明显高于非手术侧和假手术组背角。鞘内注射CBX 3h后,PWMT平均阈值由(2.5±1.0)g上升到(20.0±3.2)g,有抑制效应, 而生理盐水组则无抑制效应。 结论 脊髓背角内的缝隙连接在因外周神经损伤引起的神经病理性痛中起重要作用。     

bFGF对神经病理性疼痛大鼠脊髓NMDA受体表达的影响

目的探讨碱性成纤维细胞生长因子(b FGF)在大鼠神经病理性疼痛中的作用及对脊髓N-甲基-D-天门冬氨酸(NMDA)受体表达的影响。方法 48只雄性SD大鼠随机分为假手术组(A组)、假手术+b FGF抗体组(B组)、SNI组(C组)、SNI+b FGF抗体组(D组),每组12只。采用坐骨神经分支选择性损伤(SNI)方法制备神经病理性疼痛模型。其中B组和D组于建模后1、6、9、13、16、20天鞘内注射b FGF抗体18μg,注射药物容量为40μL。A、C组则在相同时间点注射相同体积磷酸盐缓冲液(PBS)。分别于术前1天和术后1、4、7、14、21天测定机械刺激缩足反射阈值(PWMT)。术后第21天处死大鼠取L4-6节段脊髓,免疫组化测定胶质纤维酸性蛋白(GFAP)表达,RTPCR及Westem blot检测NMDA受体亚基NR1、NR2A、和NR2B表达变化。结果与A组和B组比较,C、D组PWMT降低,脊髓GFAP、NR1和NR2B表达升高(P0.05)。与C组比较,D组PWMT升高,脊髓GFAP、NR1和NR2B表达降低(P0.05)。结论鞘内注射b FGF能缓解SNI大鼠神经病理性疼痛,其机制可能与其调节NMDA受体表达有关。     

鞘内注射丹参酮ⅡA对坐骨神经慢性压迫性痛大鼠脊髓背角N-甲基-D-天冬氨酸受体表达的影响

目的:研究丹参酮ⅡA对坐骨神经慢性压迫性痛大鼠脊髓背角内N-甲基-D-天冬氨酸受体2B亚基(NR2B)表达的影响,探讨丹参酮ⅡA的镇痛机制。方法:SD雄性大鼠随机分为假手术组和模型组。模型组又分为生理盐水组和处理组。模型组在手术当日及术后每日在大鼠鞘内注射生理盐水0.1 ml和丹参酮ⅡA 20 mg/kg,连续注射14 d。检测各组大鼠在手术前及术后14 d的机械痛阈和热痛阈;术后第14天,免疫组织化学检测大鼠脊髓背角内NR2B的表达。结果:与假手术组比较,生理盐水组大鼠的机械痛阈和热痛阈明显降低,NR2B的表达增多;与生理盐水组比较,处理组的机械痛阈和热痛阈明显升高,脊髓背角内NR2B的表达下降,差异均有统计学意义。结论:鞘内注射丹参酮ⅡA对坐骨神经慢性压迫性痛模型大鼠的镇痛作用可能与降低脊髓背角内NR2B的表达有关。     

坐骨神经选择性损伤痛模型小鼠脊髓背角线粒体解偶连蛋白UCP4的表达变化

目的:观察线粒体保护蛋白解偶联蛋白4(uncoupling protein 4,UCP4)在坐骨神经选择性损伤(sparednerve injury,SNI)模型小鼠脊髓背角中的表达变化。方法:健康C57BL/6小鼠分为假手术对照组(n=21)和坐骨神经分支选择性损伤SNI组(n=21),实验组损伤后饲养3,7,14 d。行为学采用测定小鼠热痛阈和Von Frey机械性痛阈;用免疫荧光组织化学染色法检测对比小鼠脊髓L3-6节段背角内UCP4免疫阳性细胞的数量。结果:SNI术后3 d,小鼠手术侧热痛阈和机械性痛阈明显低于假手术组,术后14 d达最低值。UCP4分布于正常小鼠脊髓背角,SNI后3 d损伤组小鼠脊髓背角中的UCP4表达降低,图像分析表明UCP4的光密度与对照组比较,差异有统计学意义(P<0.05);脊髓背角中UCP4的表达在14 d时其降低程度最明显,图像分析表明光密度与对照组、3d和7 d比较,差异均有统计学意义(P<0.05)。结论:SNI后脊髓背角线粒体保护蛋白UCP4表达降低可能参与神经病理性疼痛的中枢敏化过程。     

鞘内注射BN50730抑制SNI大鼠痛敏和脊髓TNF-α的表达

目的： 观察鞘内注射血小板活化因子受体拮抗剂BN50730对坐骨神经分支选择损伤（SNI）神经病理痛大鼠痛阈及脊髓肿瘤坏死因子α（TNF-α）表达的影响,探讨脊髓血小板活化因子(PAF)及其受体参与痛觉信号调节的可能机制。方法: 鞘内置管的Sprague-Dawley大鼠24只随机等分为4组：假手术组,SNI组,SNI+DMSO对照组和SNI+BN50730组,建立SNI疼痛模型,手术后1、3、5、7、10和14 d鞘内给药并测痛阈,第14 d取腰段脊髓免疫组化法和ELISA法检测脊髓TNF-α的表达。结果: SNI神经损伤大鼠机械缩爪阈值明显降低(P<0.05),同侧脊髓背角TNF-α表达增强,ELISA检测脊髓TNF-α含量升高(P<0.05);鞘内应用BN50730降低脊髓TNF-α的表达,同时伴有大鼠痛行为的改善。各组大鼠辐射热缩爪潜伏期无明显差异。结论: BN50730对SNI神经病理性疼痛有治疗作用,TNF-α的表达下调可能与其镇痛机制有关。     

SAHA对骨癌痛大鼠脊髓背角内谷氨酸转运体1表达的影响

目的:通过观察辛二酰苯胺异羟肟酸(Suberoylanilide Hydroxamic Acid,SAHA)对于骨癌痛(cancerinduced bone pain,CIBP)大鼠脊髓内谷氨酸转运体1(glutamate transporter 1,GLT-1)表达的影响,探讨GLT-1参与SAHA镇痛的相关机制。方法:将体重180~220 g雌性SD大鼠随机分为4组:Sham+vehicle组(A)、Sham+SAHA组(B)、CIBP+vehicle组(C)、CIBP+SAHA组(D)。经腹膜腔注射50 mg/kg SAHA,1/d。利用von Frey纤维测量大鼠手术侧机械缩足反射阈值(paw withdrawal threshod,PWT)。上述4组大鼠在不同时间点处死后取其腰膨大段脊髓,应用免疫组织化学染色和Western Blot方法观察大鼠腰膨大节段手术侧脊髓背角内GLT-1的表达情况。结果:与A组相比,C组大鼠PWT自术后第7 d开始显著下降,且一直持续至术后第14 d(P0.01),脊髓背角内GLT-1水平逐渐下调,呈时间依赖性(P0.05)。D组与C组相比,PWT升高(P0.05),术侧脊髓背角内GLT-1表达增加(P0.05)。结论:腹膜腔注射SAHA能够有效缓解骨癌痛,其部分机制可能与促进脊髓背角内GLT-1的表达有关。     

脊髓刺激术对神经病理性痛模型大鼠脊髓背角内NR2B受体和星形胶质细胞激活的影响

目的:探讨脊髓刺激术(spinal cord stimulation,SCS)对L5脊神经结扎(spinal nerve ligation,SNL)诱导的神经病理性痛(neuropathic pain,NP)大鼠脊髓背角内NMDA受体亚单位NR2B的表达和星形胶质细胞激活的影响。方法:成年雄性SD大鼠48只,随机分为4组:正常组(不做任何处理);SCS组(植入SCS装置并给予SCS刺激);SNL+sham SCS组(给予SNL手术并植入SCS装置,但不进行刺激);SNL+SCS组(SNL手术并给予SCS刺激)。SCS刺激是在SNL术后第6～10 d进行(8 h/d),第10 d刺激结束后处死动物。运用行为学方法检测慢性痛状态下大鼠后肢对机械性刺激的反应阈值;采用免疫组织化学染色和Western blot方法分别检测脊髓背角内NR2B和星形胶质细胞的标志物GFAP的表达变化。结果:(1)SNL术后大鼠手术侧后足机械性痛敏显著增加,第6～10 d给予SCS刺激后,可观察到大鼠的痛行为学表现有明显缓解;(2)免疫组化结果显示:与SNL+sham SCS组相比,SNL+SCS组大鼠脊髓背角内NR2B和GFAP免疫阳性细胞的数量显著减少;(3)Western blot结果显示:给予SCS刺激后,SNL大鼠腰膨大段脊髓背角内NR2B的表达量显著下调,同时GFAP的表达量也明显有所降低。结论:给予SCS刺激可以有效地缓解SNL模型大鼠的神经病理性痛的行为学表现;该作用可能与SCS刺激抑制脊髓背角内NR2B的表达和星形胶质细胞的激活密切相关。     

谷氨酰胺合成酶在神经病理性疼痛大鼠脊髓背角的表达

目的:检测谷氨酰胺合成酶(GS)在保留性坐骨神经分支选择性结扎模型(SNI)大鼠脊髓背角的表达与定位,并探讨其在神经病理性疼痛中的作用机制。方法:48只雄性SD大鼠随机分为假手术组(sham组)和SNI组。两组大鼠分别于术前1 d、术后1、3、7和14 d测量机械痛域(PWT),并于术后相应时间点处死,采用Western Blot检测L_(4-6)节段脊髓组织中GS、p-p38、IL-10和TNF-α的表达情况;免疫荧光观察脊髓背角GS的表达与定位情况。结果:与sham组相比,SNI组大鼠PWT于术后1 d开始降低(P 0.05),术后3、7和14 d出现明显差异(P 0.05),模型制备成功。术后3 d和7 d,SNI组大鼠脊髓背角GS、TNF-α和p-p38表达量较sham组明显增高(P 0.05); IL-10表达逐渐下降,在术后7 d和14 d有统计学差异(P 0.05)。结论:GS高表达并主要定位于脊髓背角的星形胶质细胞,GS可能通过p38 MAPK通路参与神经病理性疼痛中的炎症因子的调控。     

大鼠延髓内脏带星形胶质细胞与神经元对选择性神经病理性痛的反应

目的 研究大鼠延髓内脏带(MVZ)内星形胶质细胞与神经元对选择性性神经病理性痛的反应.方法 25只成年 SD 大鼠,其中15只为接受左侧坐骨神经分支选择性损伤(SNI)组,5只作为假手术组,5只为对照组.在术前、术后10d、20d、30d(每时段5只)观察大鼠疼痛行为学并检测机械刺激缩足反射阈值(PWMT)的变化;应用抗Fos蛋白与抗胶质原纤维酸性蛋白(GFAP)或抗Fos蛋白与抗酪氨酸羟化酶(TH)的单一或双重免疫荧光法染色,Confocal显微镜下观察延髓MVZ内GFAP标记的星形胶质细胞的荧光强度,Fos/ GFAP双标记星形胶质细胞以及Fos/TH双标记神经元的平均数. 结果 SNI组大鼠与对照组或假手术组相比,术后10d其痛敏增高(PWMT值降低),20d痛敏达到高峰(PWMT值最低).免疫荧光染色显示:SNI术后MVZ内星形胶质细胞表现为激活型,GFAP免疫荧光强度明显增加;孤束核及腹外侧区的Fos/GFAP双标记星形胶质细胞及Fos/TH双标记神经元的平均值显著增高,SNI术后20d达到高峰. 结论 SNI术后MVZ内的星形胶质细胞和神经元均被激活.     

Effects of intrathecal injection of prednisolone acetate on expression of NR2B subunit and nNOS in spinal cord of rats after chronic compression of dorsal root ganglia

N-methyl-D-aspartate receptor subunit 2B (NR2B) and neuronal nitric oxide synthase (nNOS) play important roles in the mechanism of neuropathic pain. To elucidate how glucocorticoids affect this mechanism, we studied the effects of intrathecal (it) injection of prednisolone acetate (PA) on a nociceptive stimulus and the changes of nNOS and NR2B subunit expression in the spinal dorsal horn of Sprague Dawley rats following chronic compression of the dorsal root ganglia (CCD). Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured for 15 days postoperatively. An it injection of PA (2.0 mg/kg) every 3 days for postoperative days 1 to 15 inhibited the thermal hyperalgesia and tactile allodynia of CCD rats. Chronic compression of the dorsal root ganglia induced time-dependent upregulation of nNOS and NR2B subunits of N-methyl-D-aspartate receptor within the spinal cord dorsal horn ipsilateral to CCD. Both upregulations were significantly diminished by it administration of PA (2.0 mg/kg), but not by lower doses of PA (0.5 or 1.0 mg/kg). The results suggest that PA upregulation of neuronal nitric oxide synthase and NR2B subunit expression in the spinal dorsal horn contributes to PA inhibition of hyperalgesia induced by chronic compression of dorsal root ganglia.     

大麻素CB_1受体活化对神经病理性疼痛大鼠脊髓背角嘌呤能P2X_2受体表达的抑制作用

目的:观察脊髓背角大麻素CB_1受体(CB_1R)在坐骨神经缩窄性损伤(CCI)所致的神经病理性疼痛中的作用及其对嘌呤能P2X_2受体表达的调节。方法:7~8周龄SD大鼠分为4组:(1)sham组;(2)CCI组;(3)CP55940+CCI组;(4)AM251+CP55940+CCI组。分别于CCI术前1 d,术后1、3、5、7、10、14 d测定热缩足反射潜伏期(TWL);免疫印迹技术检测各组大鼠损伤侧L_4~L_6段脊髓背角P2X_2受体表达。结果:CCI术后大鼠出现热痛敏,TWL明显缩短;鞘内给予非选择性大麻素受体激动剂CP55940可明显延长CCI大鼠TWL(P0.05);预先鞘内注射CB_1R拮抗剂AM251(0.05 mg/kg)可显著降低CP55940的镇痛效果(P0.05)。免疫印迹实验结果显示:CCI大鼠脊髓背角P2X_2受体在术后7、14 d表达明显增加(P0.05);鞘内给予CP55940可显著降低P2X_2受体表达(P0.05),而预先给予AM251可降低CP55940抑制P2X_2受体表达的效应(P0.05)。结论:脊髓背角CB_1受体激活对CCI所致的神经病理性疼痛具有良好的镇痛作用,其镇痛效应可能与抑制CCI大鼠嘌呤能P2X_2受体表达有关。     

Proteomic analysis of the dorsal spinal cord in the mouse model of spared nerve injury-induced neuropathic pain

Peripheral nerve injury often causes neuropathic pain and is associated with changes in the expression of numerous proteins in the dorsal horn of the spinal cord. To date, proteomic analysis method has been used to simultaneously analyze hundreds or thousands of proteins differentially expressed in the dorsal horn of the spinal cord in rats or dorsal root ganglion of rats with certain type of peripheral nerve injury. However, a proteomic study using a mouse model of neuropathic pain could be attempted because of abundant protein database and the availability of transgenic mice. In this study, whole proteins were extracted from the ipsilateral dorsal half of the 4th–6th lumbar spinal cord in a mouse model of spared nerve injury (SNI)-induced neuropathic pain. In-gel digests of the proteins size-separated on a polyacrylamide gel were subjected to reverse-phase liquid-chromatography coupled with electrospray ionization ion trap tandem mass spectrometry (MS/MS). After identifying proteins, the data were analyzed with subtractive proteomics using ProtAn, an in-house analytic program. Consequently, 15 downregulated and 35 upregulated proteins were identified in SNI mice. The identified proteins may contribute to the maintenance of neuropathic pain, and may provide new or valuable information in the discovery of new therapeutic targets for neuropathic pain.     

Tactile allodynia can occur in the spared nerve injury model in the rat without selective loss of GABA or GABA(A) receptors from synapses in laminae I-II of the ipsilateral spinal dorsal horn

Although there is evidence that reduced inhibition in the spinal dorsal horn contributes to neuropathic pain, the mechanisms that underlie this are poorly understood. We have previously demonstrated that there is no loss of neurons from laminae I-III in the spared nerve injury (SNI) model [Polgár E, Hughes DI, Arham AZ, Todd AJ (2005) Loss of neurons from laminas I-III of the spinal dorsal horn is not required for development of tactile allodynia in the SNI model of neuropathic pain. J Neurosci 25:6658-6666]. In this study we investigated whether there was a difference between ipsilateral and contralateral sides in the levels of GABA, the vesicular GABA transporter (VGAT), or the beta(3) subunit of the GABA(A) receptor at synapses in the medial part of the superficial dorsal horn in this model. Tissue from rats that had undergone SNI 4 weeks previously was examined with an electron microscopic immunogold method to reveal GABA, following pre-embedding detection of GABA(A) beta(3) to allow identification of GABAergic terminals. Assessment of labeling for the GABA(A) beta(3) subunit and VGAT was performed by using immunofluorescence and confocal microscopy. We found no difference in the intensity of immunolabeling for any of these markers on the two sides of the superficial dorsal horn. These results suggest that there is no significant loss of GABAergic boutons from the denervated area after SNI (which is consistent with the finding that neuronal death does not occur in this model) and that there is no depletion of GABA or GABA(A) receptors at GABAergic synapses within this region. An alternative explanation for disinhibition after nerve injury is that it results from reduced excitatory drive to GABAergic dorsal horn neurons following loss of primary afferent input to these cells.