鞘内注射银杏内酯B对神经病理痛大鼠痛阈及脊髓c-fos表达的影响

目的:观察鞘内注射银杏内酯B(BN52021)对SNI神经病理痛大鼠痛阈及脊髓c-fos表达的影响,探讨脊髓血小板活化因子及其受体参与痛觉信号调节的可能机制.方法:鞘内置管后的SD大鼠24只随机等分为4组:假手术组(sham组),SNI组,SNI+DMSO对照组和SNI+BN52021组,建立SNI疼痛模型,手术后1,3,5,7,10和14d鞘内给药并测痛阈,第14d取大鼠腰段脊髓,冰冻切片,免疫组织化学染色检测Fos免疫阳性细胞.结果:SNI神经损伤大鼠机械缩爪阈明显降低(P<0.05),同侧脊髓背角浅层内Fos阳性神经元明显增多(P<0.05);鞘内应用银杏内酯B明显减少脊髓背角神经元c-fos的表达,同时伴有大鼠机械异常痛敏的减轻,各组大鼠辐射热缩爪潜伏期无明显差异.结论:鞘内注射银杏内酯B可减轻SNI大鼠机械异常痛敏,抑制神经损伤后脊髓背角c-fos的表达.     

慢性坐骨神经结扎神经痛大鼠脊髓nNOS阳性神经元的表达

目的:探讨慢性坐骨神经结扎(CCI)神经病理性疼痛大鼠脊髓背角nNOS阳性神经元的表达。方法:SD大鼠40只,随机分为五组,每组8只,即naive组、sham组、CCI5d组、CCI10d组;CCI15d组;测定各组大鼠机械缩腿阈值(MWT)和热缩腿潜伏期(TWL);同时sham组大鼠在术后5d、CCI各组分别在术后5d、10d、15d断头处死取脊髓腰膨大,采用免疫组化法测定脊髓背角nNOS阳性神经元的表达。结果:CCI大鼠在手术后形成稳定的痛敏,与naive组和sham组大鼠比较有显著差异;naive组大鼠和sham组大鼠脊髓背角仅见少量nNOS阳性神经元的表达,且两组间无统计学意义;CCI各组大鼠脊髓背角nNOS阳性神经元的表达明显增多,与naive组和sham组比较差异显著。结论:慢性坐骨神经结扎(CCI)神经痛大鼠脊髓背角nNOS阳性神经元的表达增加,脊髓背角nNOS可能参与了CCI大鼠神经病理性疼痛的形成。     

鞘内注射右美托咪定对坐骨神经慢性缩窄性损伤大鼠脊髓背角肿瘤坏死因子α蛋白表达的影响

目的探讨鞘内注射右美托咪定（ DEX）对坐骨神经慢性缩窄性损伤（ CCI）大鼠脊髓背角肿瘤坏死因子α（ TNF-α）蛋白表达的影响。方法成年Sprague-Dawley雄性大鼠44只随机分为四组（ n＝11）：假手术组（ sham组）,坐骨神经慢性缩窄性损伤组（ CCI组）,生理盐水组（ CCI＋NS组）和右美托咪定组（ CCI＋DEX组）。采用von Frey纤毛分别测定了sham组和CCI组术前及术后1、3、5、7、14 d,以及CCI＋NS组和CCI＋DEX组术后第7天鞘内给药前和给药后1、2、3 h的机械刺激抬腿反应阈值（ PWT）。 sham组和CCI组在术后第7天,CCI＋NS组和CCI＋DEX组在术后第7天鞘内给药后1 h时间点分别余5只大鼠处死取脊髓背角,采用Werstern blot法测定TNF-α蛋白表达。结果与sham组相比,CCI组PWT自术后第3天开始出现下降,并持续至第14天（ P＜0.001）;与CCI＋NS组相比,CCI＋DEX组在给药后1 h即出现明显镇痛作用,且持续至给药后2 h（P＜0.01或P＜0.001）。 Werstern blot结果显示,和sham组比较,CCI组和CCI＋NS组大鼠脊髓背角TNF-α蛋白表达上调（ P＜0.05）;与CCI＋NS组比较,CCI＋DEX组TNF-α蛋白表达下调（ P＜0.05）。结论鞘内注射右美托咪定可通过抑制CCI大鼠脊髓背角TNF-α蛋白表达减轻神经病理性疼痛。     

鞘内注射吗啡对坐骨神经慢性压迫性损伤大鼠腰段脊髓后角神经元中c-fos蛋白表达的影响

目的 坐骨神经慢性压迫性损伤(CCI)可以引起腰段脊髓后角中c-fos的表达.μ-阿片受体长期以来被认为与脊髓中的镇痛机制有关,而吗啡作为μ-阿片受体激动剂被应用于病理性疼痛的治疗中.本实验通过给坐骨神经CCI大鼠模型鞘内注射吗啡,观察其对脊髓后角中c-fos表达的影响.方法 23只Sprague-Dawley大鼠随机分为三组.其中B、C两组大鼠接受右侧坐骨神经外周结扎手术,而A组为假手术组.9 d后,A、C两组大鼠接受鞘内注射吗啡同时给B组大鼠鞘内注射生理盐水.注射后6 d,解剖三组大鼠并取出L3～L5节段的脊髓制成40μm的冰冻切片.标本在室温下进行荧光免疫染色后制成玻片.使用激光共焦点显微镜下观察各脊髓切片标本双侧c-fos的染色情况.结果 三组大鼠手术侧同侧的脊髓后角中c-fos阳性神经元较对侧明显增多.但是c组大鼠脊髓后角同侧的c-fos阳性神经元较B组少.结论 μ-阿片受体激动剂能明显减少CCI大鼠腰段脊髓后角中c-fos的表达.     

鞘内泵入布托啡诺对神经病理性疼痛大鼠脊髓P物质表达的影响

目的:观察鞘内泵入布托啡诺对神经病理性疼痛大鼠脊髓P物质的影响,探讨鞘内泵入布托啡诺治疗神经病理性疼痛的可行性.方法:24只SD大鼠随机分为3组,空白对照组(B组),不实施任何手术;对照组(C组),右肢制备坐骨神经慢性压迫损伤模型(CCI)及鞘内置管后鞘内泵入生理盐水10μL/d;布托啡诺组(TB组),CCI及鞘内置管后泵入布托啡诺24μg/d.C组和TB组术后第4天开始鞘内给药,连续给药7 d.第11天于给药2 h后大鼠灌注固定,采用免疫组化方法检测脊髓背角P物质.结果:成功制作CCI模型,无鞘内导管脱出现象,且注药成功,无疼痛行为学差异.与B组相比,C组和TB组脊髓背角P物质表达明显增加(P＜0.01);与C纽相比,TB组脊髓背角P物质表达明显降低(P＜0.01).结论:鞘内泵入布托啡诺可以通过减少脊髓P物质表达而发挥镇痛作用,布托啡诺可以通过鞘内给药治疗神经病理性疼痛.     

曲马多抑制大鼠神经病理性痛和脊髓背角NR2B表达

目的:研究曲马多对神经病理性痛(neuropathic pain,NP)大鼠的镇痛作用及对脊髓背角N-甲基-D-天门冬氨酸(N-Methyl-D-Aspartate,NMDA)受体NR2B亚基表达的影响.方法:雄性wistar大鼠,随机分为3组(每组10只):假手术组(Sham operation,SO组)、NP模型组(NP组)、曲马多处理组(Tramadol组,T组).NP模型采用慢性坐骨神经压迫损伤的方法制作.各组大鼠分别于术前和术后3、7、10、14d测术侧后爪机械缩足阈值(mechanical withdrawal threshold,MWT)和热缩足潜伏期(thermal withdrawal latency,TWL).T组于术后3d开始腹腔注射曲马多注射液(20 mg/kg),术后14d取大鼠脊髓背角用免疫荧光法与RT-PCR方法检测NR2B蛋白和mRNA表达水平.结果:与SO组比较,NP组术后痛阈明显降低,NR2B表达水平明显升高(P＜ 0.05).与NP组比较,T组术后痛阈升高,NR2B表达水平明显降低(P＜0.05).T组和SO组比较,痛阈和NR2B表达水平差异无统计学意义.结论:曲马多可反转NP模型脊髓背角的NR2B表达上调并具有镇痛作用.     

SNI模型大鼠脊髓背角N-甲基-D-天冬氨酸受体和降钙素基因相关肽的表达

【目的】观察坐骨神经分支选择结扎切断模型(Spared nerve injury model,SNI)痛阈及脊髓背角N-甲基-D-天冬氨受体(NMDAR)、降钙素基因相关肽(CGRP)表达的变化。【方法】健康雄性SD大鼠27只,体重220~280 g。随机分为3组(n=9)。对照组(C组);假手术组(sham组);坐骨神经分支选择结扎切断模型组(SNI组)。在模型制作前1 d和模型制作后14 d内,每组均进行疼痛行为学观察。所有组别均在模型制作后d2、d7、d14天观察行为学改变后分批取材(每批3只),用免疫组化法观察大鼠L5节段水平脊髓背角NMDAR和CGRP的表达。【结果】与C组和sham组比较,SNI组在SNI术后均出现机械性异常疼痛痛阈降低(P<0.01),但热刺激后爪退缩潜伏时间无统计学意义(P>0.05);同时SNI组大鼠脊髓背角NMDAR和CGRP免疫阳性产物数量和表达增加(P<0.01)。【结论】SNI模型大鼠出现典型的疼痛行为学特征时,其脊髓背角NMDAR和CGRP表达也明显增强,并且脊髓背角NMDAR和CGRP的变化趋势大体相同。     

电针镇痛与神经病理性疼痛大鼠脊髓大麻素2受体表达

目的:观察电针对慢性坐骨神经缩窄性损伤(CCI)模型大鼠的镇痛效果及脊髓背角、背根神经节大麻素2受体(CB2)表达,探讨电针镇痛可能的机制.方法:健康SD雄性大鼠共40只,随机分为CCI假手术组(n=10);CCI对照组(n=10);CCI假电针组(n=10);CCI电针组(n=10).所有大鼠均在术前、术后第9、11、13、15、16d进行机械性痛阈测定;各组大鼠于术后第16d,采用Western blot法测定脊髓背角、背根神经节CB2受体蛋白表达.结果:CCI对照组、CCI假电针组和CCI电针组大鼠在治疗前机械性痛阈较术前明显下降,与同一时间段CCI假手术组大鼠比较差异有统计学意义(P＜0.05).治疗后6d,CCI电针组机械性痛阈较治疗前有一定改善(P＜0.05);CCI电针组与CCI假电针组和CCI对照组比较脊髓背角、背根神经节CB2的表达有下降的趋势,但差异无统计学意义(P＞0.05).结论:本研究观察到电针治疗能够在一定程度上改善CCI模型大鼠的机械性痛阈,起到一定的镇痛效果,但是本研究结果未能提示其镇痛机制有脊髓背角、背根神经节CB2的参与.     

鞘内注射AIP对神经病理性痛大鼠的镇痛作用及脊髓背角神经元磷酸化CREB的影响

目的:探讨钙/钙调素依赖性蛋白激酶Ⅱ(calcium/calmodulin-dependent protein kinaseⅡ,CaMKⅡ)在神经病理性疼痛中的作用。方法:坐骨神经选择性损伤(SNI)大鼠模型,随机分为4组(n=8):SNI组,Sham组,NS组,AIP组,后两组分别于术前20 min鞘内注射10μl的生理盐水或10%的AIP。于术后1d、2d、3d、4d、6d、8d、10d、14d测定大鼠机械缩足反射阈值(mechanical with-drawal threshold,MWT)。分别于术后1d、3d、7d取大鼠脊髓腰段,用免疫组织化学法(n=6)检测脊髓背角磷酸化pCaMKⅡ的表达;Western blot法(n=4)检测脊髓背角神经元细胞核内pCREB的表达。结果:术后1~3d AIP组大鼠MWT较NS组明显升高(P<0.01);术前鞘内注射AIP在术后1d、3d能够使脊髓背角pCaMKⅡ的表达减少,同时脊髓背角神经元细胞核内pCREB的表达也明显减少。结论:CaMKⅡ参与了神经病理性痛的形成,其作用部分通过CREB介导。     

氯胺酮鞘内注射对慢性坐骨神经损伤大鼠脊髓 NMDA-2B mRNA表达的影响

目的：探讨氯胺酮连续鞘内注射对慢性坐骨神经损伤大鼠脊髓背角N-甲基-D天冬氨酸亚基（NR2B）mRNA表达的影响。方法：雄性SD大鼠18只，随机分为假手术组、CCI组和氯胺酮组。按Bennett等法制作CCI模型，测von-Frey丝触痛及冷水阈值，采用原位杂交技术检测各组脊髓背角NR2B mRNA表达的变化。结果：CCI组痛阈显著下降，冷水阈显著升高，脊髓背角有大量NR2B mRNA阳性表达（P＜0．01）；氯胺酮组仅出现轻度痛敏症状，NR2B mRNA表达受到明显抑制（P＜0．01）。结论：NR2B mRNA表达上调可能是神经损伤后慢性疼痛的发病机制之一，氯胺酮可抑制其表达从而发挥一定程度的镇痛作用。     

胫骨骨癌痛模型大鼠鞘内注射舒芬太尼后脊髓背角N-甲基-D-天冬氨酸受体及降钙素基因相关肽的表达

背景:临床和动物实验证实舒芬太尼鞘内注射有明显的镇痛效果,但其机制尚不明确。目的:观察鞘内注射舒芬太尼对骨癌痛大鼠痛阈及脊髓背角N-甲基-D-天冬氨酸受体、降钙素基因相关肽表达的影响。方法:健康SD大鼠36只随机等分为对照组、假手术组、模型组和舒芬太尼组。后2组利用乳腺癌细胞腹水制备胫骨骨癌痛模型,假手术组注射加热灭活后的死细胞。模型组和舒芬太尼组在建模后15d内每天鞘内注射生理盐水和舒芬太尼。结果与结论:与对照组和假手术组比较,模型组大鼠在建模后第12和14天脊髓背角N-甲基-D-天冬氨酸受体和降钙素基因相关肽表达增加(P<0.01),且出现机械性异常疼痛痛阈降低,热刺激后爪退缩潜伏时间缩短(P<0.01);而与模型组比较,舒芬太尼组大鼠,在注药后第12和14天脊髓背角浅层N-甲基-D-天冬氨酸受体和降钙素基因相关肽的表达降低(P<0.01),且机械刺激痛阈提高以及热刺激后爪潜伏期延长(P<0.01)。提示鞘内注射舒芬太尼对骨癌痛大鼠具有明显的抗伤害效应,其机制与抑制大鼠脊髓背角N-甲基-D-天冬氨酸受体和降钙素基因相关肽表达有关。     

Perturbing PSD-95 Interactions With NR2B-subtype Receptors Attenuates Spinal Nociceptive Plasticity and Neuropathic Pain

Peripheral inflammation or nerve injury induces a primary afferent barrage into the spinal cord, which can cause N-methyl -aspartate (NMDA) receptor-dependent alterations in the responses of dorsal horn sensory neurons to subsequent afferent inputs. This plasticity, such as “wind-up” and central sensitization, contributes to the hyperexcitability of dorsal horn neurons and increased pain-related behavior in animal models, as well as clinical signs of chronic pain in humans, hyperalgesia and allodynia. Binding of NMDA receptor subunits by the scaffolding protein postsynaptic density protein-95 (PSD-95) can facilitate downstream intracellular signaling and modulate receptor stability, contributing to synaptic plasticity. Here, we show that spinal delivery of the mimetic peptide Tat-NR2B9c disrupts the interaction between PSD-95 and NR2B subunits in the dorsal horn and selectively reduces NMDA receptor-dependent events including wind-up of spinal sensory neurons, and both persistent formalin-induced neuronal activity and pain-related behaviors, attributed to central sensitization. Furthermore, a single intrathecal injection of Tat-NR2B9c in rats with established nerve injury-induced pain attenuates behavioral signs of mechanical and cold hypersensitivity, with no effect on locomotor performance. Thus, uncoupling of PSD-95 from spinal NR2B-containing NMDA receptors may prevent the neuronal plasticity involved in chronic pain and may be a successful analgesic therapy, reducing side effects associated with receptor blockade.     

坐骨神经分支选择性损伤模型大鼠右美托咪啶鞘内注射的镇痛作用

背景：右美托咪啶是一种高效、高选择性的α2肾上腺素受体激动剂,具有镇静、镇痛、抗焦虑等作用,对呼吸影响小。 目的：观察鞘内注射右美托咪啶对坐骨神经分支选择性损伤模型大鼠的镇痛作用。 方法：雄性SD大鼠36只按随机数字表法等分为正常对照组、生理盐水组和右美托咪啶组,后2组结断腓总神经和胫神经建立坐骨神经分支选择性损伤大鼠模型,右美托咪啶组在坐骨神经分支选择性损伤后14 d内每天鞘内注射右美托咪啶3μg/kg,生理盐水组大鼠注射生理盐水。 结果与结论：与生理盐水组相比,右美托咪啶组大鼠给药后的机械性缩足反射阈值与热缩足潜伏期显著性升高（P〈0.05）,脊髓背角中神经型一氧化氮合酶mRNA和蛋白的表达水平明显降低（P〈0.05）,脊髓背角神经元损伤程度明显减轻,且在给药14 d时脊髓背角神经型一氧化氮合酶mRNA和蛋白的表达水平及脊髓背角神经元损伤情况与正常对照组接近。提示鞘内注射右美托咪啶可抑制脊髓背角神经型一氧化氮合酶的表达,减轻大鼠坐骨神经损伤引起的疼痛。     

Distinct roles of group III metabotropic glutamate receptors in control of nociception and dorsal horn neurons in normal and nerve-injured Rats

Increased glutamatergic input to spinal dorsal horn neurons constitutes an important mechanism for neuropathic pain. However, the role of group III metabotropic glutamate receptors (mGluRs) in regulation of nociception and dorsal horn neurons in normal and neuropathic pain conditions is not fully known. In this study, we determined the effect of the group III mGluR specific agonist L(+)-2-amino-4-phosphonobutyric acid (L-AP4) on nociception and dorsal horn projection neurons in normal rats and a rat model of neuropathic pain. Tactile allodynia was induced by ligation of L5/L6 left spinal nerves in rats. Allodynia was determined by von Frey filaments in nerve-injured rats. The nociceptive threshold was tested using a radiant heat and a Randall-Selitto pressure device in normal rats. Single-unit activity of ascending dorsal horn neurons was recorded from the lumbar spinal cord in anesthetized rats. An intrathecal (5-30 microg) L-AP4 dose-dependently attenuated allodynia in nerve-injured rats but had no antinociceptive effect in normal rats. Topical spinal application of 5 to 50 microM L-AP4 also significantly inhibited the evoked responses of ascending dorsal horn neurons in nerve-ligated but not normal rats. Furthermore, blockade of spinal group III mGluRs significantly decreased the withdrawal threshold and increased the evoked responses of dorsal horn neurons in normal but not nerve-injured rats. These data suggest that group III mGluRs play distinct roles in regulation of nociception and dorsal horn neurons in normal and neuropathic pain states. Activation of spinal group III mGluRs suppresses allodynia and inhibits the hypersensitivity of dorsal horn projection neurons associated with neuropathic pain.     

鞘内注射醋酸泼尼松龙对背根节压迫大鼠的镇痛作用及其机制的探讨

目的：研究鞘内注射醋酸泼尼松龙（PA）对背根节慢性压迫（CCD）大鼠痛阈和脊髓背角nNOS表达的影响及其镇痛机制.方法：鞘内置管手术成功雄性SD大鼠100只,随机分为7天组和15天组两组,每组再随机分为假手术（Sham）组,人工脑脊液（ACSF）组,鞘内注射PA 0.5、1.0、2.0mg/kg组（n=10）.分别于CCD术前（0）及术后1,3,5,7,9,11,13,15天采用von Frey纤毛机械刺激法和热辐射刺激法评定大鼠机械刺激缩足反射阈值（PWMT）和热刺激缩足反射潜伏期（PWTL）;术后第7天和第15天运用免疫组织化学法和Western blot法观察脊髓背角nNOS表达的变化.结果：与术前基础阈值相比,除假手术组外,CCD术后各组的PWMT和PWTL均出现明显地下降（P＜0.01）,各组间无明显差异（P＞0.05）.术后第5天开始,PA 2.0 mg/kg组与ACSF组相比,PWMT和PWTL显著升高（P＜0.05）.免疫组织化学方面,背根节压迫后第7和第15天,ACSF组与PA 0.5、1.0 mg/kg组脊髓背角阳性神经元数量明显增多,三组之间比较无显著差异（P＞0.05）.PA 2.0 mg/kg组和ACSF相比,第7天和第15天均显著降低（P＜0.01）.脊髓背角Westernblot检测与免疫组织化学的结果基本一致.结论：鞘内注射PA有镇痛作用,其作用机制可能与抑制脊髓背角nNOS的表达有关.     

鞘内注射右美托咪定干预慢性神经痛模型大鼠脊髓背角蛋白激酶C的表达

背景：右美托咪啶是一种高效、高选择性的α2肾上腺素受体激动剂,具有镇静、镇痛、抗焦虑等作用,对呼吸影响小。目的：观察鞘内注射右美托咪定对坐骨神经分支选择性损伤模型大鼠的镇痛作用。方法：雄性SD大鼠60只,随机均分为3组。除正常对照组外,另2组大鼠建立坐骨神经分支选择性损伤模型,右美托咪定组在造模后14 d内每天鞘内注射右美托咪定3μg/kg,生理盐水组在同时注射等容量的生理盐水。于坐骨神经分支选择性损伤模型前、术后鞘内给药前和鞘内给药后2,7,14 d测定大鼠热刺激缩足反射潜伏期和机械刺激缩足反射痛阈值,并在术后第2,7,14天鞘内注射药物后,每组每个时间点分别处死4只大鼠,取其L4-6脊髓,RT-PCR及Western blot法分别检测脊髓背角蛋白激酶C mRNA及蛋白水平的表达情况,苏木精-伊红染色检测脊髓背角神经元形态学变化,免疫组织化学法检测脊髓背角蛋白激酶C蛋白表达的水平及分布情况。结果与结论：与正常对照组比较,给药前、给药后各时点生理盐水组和右美托咪定组热刺激缩足反射潜伏期和机械刺激缩足反射痛阈值均明显降低（P〈0.05）;与生理盐水组比较,给药后各时点右美托咪定组热刺激缩足反射潜伏期延长和机械刺激缩足反射痛阈值均明显升高（P〈0.05）;右美托咪定组脊髓背角蛋白激酶C表达明显明显低于生理盐水组,且在给药14 d时达到最低接近于正常对照组。右美托咪定组脊髓背角神经元凋亡程度也较生理盐水组轻微,在给药14 d时神经元形态基本接近正常对照组。提示鞘内注射右美托咪定可减轻坐骨神经分支选择性损伤模型引起的痛敏,可能与其抑制脊髓背角蛋白激酶C的表达相关。     

Antihyperalgesic effects of intrathecally administered magnesium sulfate in rats

Intrathecal administration of MgSO(4) is reported to cause paralysis. However, the characteristic sensory disturbances have not been thoroughly investigated. We examined the effect of intrathecally administered MgSO(4) on the nociceptive threshold, using three different nociceptive measures, formalin test, hot plate test and paw pressure test in rats. The dose of MgSO(4) was 30, 100 or 300 microg. In acute nociceptive tests, intrathecal MgSO(4) did not cause any significant changes in the pain threshold. However, phase 2 of the formalin test was suppressed dose-dependently. It is known that spinal NMDA receptors are involved in the changes seen during the second (tonic) phase of the formalin test and in vitro studies showed that Mg(2+) can cause voltage-dependent blockade of NMDA receptor channel in the neurons of spinal dorsal horn. Thus, the suppressive effect of intrathecally administered MgSO(4) on the tonic inflammation-evoked behavior is mediated by the spinal NMDA receptors. Our results suggest that intrathecal administration of MgSO(4) may be therapeutically beneficial for patients with tonic pain involving the spinal NMDA receptors.     

脊髓 GAT-1在大鼠背根节慢性压迫神经病理性疼痛中的作用

[目的]探讨脊髓γ-氨基丁酸转运体-1（GAT-1）在大鼠慢性背根神经节压迫（CCD）神经病理性疼痛中的作用。[方法]选择雄性SD大鼠72只,随机分为假手术组（A组,n＝24）、CCD组（B组,n ＝24）、鞘内NO-711＋CCD组（ C组,n ＝24）,三组再按不同时段分为6个亚组（ n ＝4）,分别于给药前（T0）、给药后1 h （T1）、4 h（T2）、8 h（T3）、16 h（T4）、24 h（T5）时间点处死大鼠取脊髓腰段进行GAT-1蛋白Western Blot实验。[结果]与假手术组相比,B组T0、T1、T2、T3、T4、T5时间点的GAT-1蛋白含量明显增加（ P ＜0．01）,鞘内注射生理盐水后,B组的GAT-1蛋白含量无明显改变（ P ＞0．05）;与B组和T0相比,鞘内注射20μg NO-711后T1、T2、T3,C组的GAT-1蛋白含量显著降低（ P ＜0．01）,鞘内给药后T4,GAT-1蛋白含量逐渐回升,与B组同一时间点比GAT-1蛋白含量仍明显降低（ P ＜0．05）,至给药后 T5 GAT-1蛋白含量回升到正常水平（ P ＞0．05）。[结论]CCD模型大鼠脊髓 GAT-1蛋白表达水平上调,GAT 抑制剂 NO-711能明显抑制CCD模型大鼠脊髓GA T-1蛋白表达水平的上调,但是不能抑制GA T-1蛋白基础表达水平。大鼠脊髓背角GA T-1蛋白表达水平的改变与大鼠CCD神经病理性疼痛的机制可能密切相关。     

Morphine tolerance increases [3H]MK-801 binding affinity and constitutive neuronal nitric oxide synthase expression in rat spinal cord. (National Medical Defense Center, Taipei, Taiwan) Br J Anaesth 2000;85:587–591.

N‐Methyl‐D‐aspartate (NMDA) receptor antagonists and nitric oxide synthase (NOS) inhibitors inhibit morphine tolerance. In the present study, a lumbar subarachnoid polyethylene (PE10) catheter was implanted for drug administration to study alterations in NMDA receptor activity and NOS protein expression in a morphine‐tolerant rat spinal model. Antinociceptive tolerance induced by intrathecal morphine infusion (10 μg h^?1) for 5 days. Co‐administered MK801 with morphine was used to inhibit the development of morphine tolerance. Lumbar spinal cord segments were removed and prepared for [³H]MK‐801 binding assays and NOS western blotting. The binding affinity of [³H]MK‐801 was higher in spinal cords of morphine‐related rats than in control rats. There was no difference in B_max. Western blot analysis showed that constitutive expression of neuronal NOS protein in the morphine‐tolerant group was twice that in the control group. This up‐regulation was partially prevented by MK‐801. The results suggest that morphine tolerance affects NMDA receptor binding activity and increases nNOS expression in the rat spinal cord. Comment by Octavio Calvillo, M.D., Ph.D. Morphine tolerance may be due to receptor down‐regulation or receptor uncoupling; activation of the NMDA‐dependent pain‐facilitatory system may also play a role. It has been proposed that NMDA receptor activation may play a role in morphine tolerance. NMDA receptor antagonists and nitric oxide synthase [NOS] inhibitors may prevent morphine tolerance. Tolerance was induced in rats by intrathecal injection of morphine [10 ug/h] for 5 days, co‐administration of MK801 [NMDA antagonist] with morphine was used to prevent morphine tolerance. Lumbar spinal cord segments were removed and prepared for [H3]MK801 binding assays and NOS western blotting. The binding affinity of labeled MK801 was higher in spinal cords of morphine tolerant rats than in control rats. Western blot analysis showed that constitutive expression of neuronal NOS protein in the morphine tolerant rats was twice that in the control group, thus, up‐regulation was prevented by MK801. The results suggest that morphine tolerance affect NMDA receptor binding activity and increase neuronal protein expression in rat the spinal cord.     

大鼠自体神经移植模型脊髓背角c-fos表达的研究

[摘要]目的：建立大鼠自体神经移植模型，观察大鼠神经恢复过程中行为学改变和机械痛觉超敏的变化以及脊髓背角c-fos表达的改变，探讨外周神经损伤再生与痛觉过敏的关系。方法：雄性Wistar大鼠40只，体重180～200g，随机分成2组每组20只，A组自体神经移植组；B组为假手术组。术后18日起检测行为学、机械刺激阈值和热缩足反射时间及c-fos表达计数。所有数据采用均值±标准差表示，组间采用t检验，用SPSS11.0软件进行统计分析，P<0.05为有统计学差异。结果：A组术后24天后机械痛阈和热缩足反射潜伏期与B组相差明显，有统计学意义。A组术侧L4～5脊髓背角与B组相比较，背角浅层c-fos计数增多，有统计学差异。A组39日和 27日c-fos表达无统计学差异，机械痛阈热缩与足反射潜伏期39日与21日有统计学差异。结论：自体神经移植模型再生神经生长进入去神经支配区域后，触觉诱发疼痛和脊髓背角浅层c-fos表达，同时出现再生神经支配区域的机械痛觉超敏和疼痛相关行为。