神经病理性疼痛大鼠鞘内注射SB203580的镇痛作用

目的 观察神经病理性疼痛大鼠鞘内注射p38丝裂原活化蛋白激酶（p38MAPK）抑制剂SB203580的镇痛作用,探讨p38MAPK信号转导通路在慢性神经病理性疼痛中的作用。方法雄性SD大鼠,体重220～250g,建立坐骨神经结扎性损伤（CCI）疼痛模型,第一部分40只CCI大鼠,随机分为5组,对照组、SB0．1μg组、SB0．5μg组、SB2．5μg组和SB5μg组,（n=8）,CCI后7d,鞘内注射2％二甲基亚砜或不同剂量的SB203580（0．1、0．5、2．5、5μg）10μl,在给药前和给药后0．5、3、6、12、24h用von Frey丝测定大鼠术侧后爪机械缩足反射阈值（MWT）;另外36只大鼠,随机分为6组（n=6）：Sham组、CCI组、DMSO组、SB0．1、0．5、5μg组,CCI后7d鞘内注射相应剂量SB203580 10μl,给药后6h取L4.5脊髓,用免疫组织化学方法检测脊髓背角磷酸化环磷酸腺苷反应元件结合蛋白（pCREB）的表达。结果CCI后大鼠产生了机械痛敏。鞘内注射SB203580剂量依赖性地提高了MWT。CCI后脊髓背角pCREB阳性神经元增加,鞘内注射SB0．5、5μg抑制了CCI引起的脊髓背角pCREB表达增加（P〈0．01）。结论鞘内注射SB203580能减轻CCI引起的痛敏,抑制脊髓背角CREB的磷酸化,p38MAPK信号通路参与慢性神经病理性疼痛。     

Continuous intrathecal clonidine administration for the treatment of neuropathic pain

In many cases, the treatment of neuropathic pain by intrathecal opioids fails to meet expectations. In a trial involving 10 patients, the intrathecal administration of clonidine combined with opioids in the treatment of chronic pain was introduced in our department for the first time. Eight patients with neuropathic pain syndromes were subjected to a continuous intrathecal clonidine application in addition to intrathecal morphine. At an average dose of 44 microg clonidine/day, a 70-100% reduction in pain was achieved. Residual non-neuropathic pain in 4 of 8 patients was successfully treated with clonidine and low doses of opioids. On the basis of the results achieved so far, we recommend that clonidine should be routinely tested for intrathecal drug administration, especially in patients with a prominent neuropathic pain component.     

鞘内注射DREAM-shRNA对神经病理性痛大鼠的镇痛效应

目的 评价鞘内注射转录因子下游调控元件拮抗因子-短发夹RNA(DREAM-shRNA)对神经病理性痛大鼠的镇痛效应.方法 健康雄性SD大鼠,体重280-320g,采用坐骨神经慢性缩窄性损伤(CCI)法建立大鼠神经病理性痛模型,于CCI后第3天鞘内置管.取鞘内置管成功的大鼠24只,随机分为4组,每组6只,假手术组(Sham组):仅暴露坐骨神经,不结扎;神经病理性痛组(NP组):于CCI后第8天鞘内注射生理盐水10μl;RNA干扰组(RNAi组):于CCI后第8天鞘内注射含DREAM-shRNA的慢病毒5μl、生理盐水5μl;空白载体组(BV组):于CCI后第8天鞘内注射慢病毒空白载体5μl、生理盐水5μl,连续注射7d.于CCI前1d(基础状态)、CCI后第7～14天(T1-8)测定热痛阈和机械痛阈,于CCI后第15天测定脊髓背角绿色荧光蛋白(GFP)的表达水平.结果 与基础值比较,NP组和BV组热痛阈降低,Sham组T1-4时热痛阈降低,RNAi组T1-4,6时热痛阈降低,4组CCI后各时点机械痛阈降低(P<0.05或0.01);与T1时比较,NP组和BV组其余时点热痛阈和机械痛阈降低.RNAi组T3-5,时热痛阈降低,T1时热痛阈和机械痛阈升高(P<0.05或0.01);与Sham组比较.NP组和BV组热痛阈和机械痛阈降低,RNAi组T2时机械痛阈降低,T5时升高(P<0.05),热痛阈差异无统计学意义(P>0.05);与NP组比较.RNAi组热痛阈和机械痛阈升高(P<0.05).仅RNAi组脊髓背角有GFP表达,其余3组脊髓背角未见GFP表达.结论 鞘内连续注射DREAM-shRNA可在一定程度上缓解大鼠神经病理性痛.     

鞘内注射氟代柠檬酸对神经病理性疼痛大鼠的镇痛作用

目的通过观察鞘内注射星形胶质细胞特异性抑制剂氟代柠檬酸(FC)对神经病理性疼痛大鼠的镇痛作用,探讨脊髓星形胶质细胞在神经病理性疼痛中的作用。方法雄性SD大鼠32只,随机分为4组(n=8),A组行假手术,鞘内注射FC的溶媒;B组行假手术,鞘内注射FC;C组制作坐骨神经慢性压迫性损伤(CCI)模型,鞘内注射FC的溶媒;D组制备CCI模型,鞘内注射FC。鞘内置管后3 d,制备CCI模型,术后1 d开始行鞘内注射,1次/d(容积1μl),连续6 d,剂量为1 nmol/μl。分别于术前1 d(基础值)、术后1、3、5、7 d测定大鼠的机械痛阈和热痛阈。术后7 d测定热痛阈后立即处死大鼠,取L4.5脊髓组织,其中4只用于免疫组化实验(测定IL-6表达),另外4只用于RT-PCR实验(测定IL-6 mRNA表达)。结果CCI可导致机械痛阈和热痛阈降低,脊髓组织IL-6 mRNA和IL-6表达增加;而鞘内注射FC可在一定程度上抑制CCI导致的上述改变。结论脊髓星形胶质细胞的激活参与大鼠神经病理性疼痛的调节。     

Antinociceptive effect of riluzole in rats with neuropathic spinal cord injury pain

Symptoms of neuropathic spinal cord injury (SCI) pain include cutaneous hypersensitivity and spontaneous pain below the level of the injury. Riluzole, an FDA-approved drug for the treatment of amyotrophic lateral sclerosis, has been demonstrated to attenuate neural excitotoxicity by blocking the effects of the excitatory amino acid glutamate on glutamate receptors and by inhibiting voltage-gated Na(+) and Ca(2+) channels. Neuropathic pain in rat models of SCI is thought to be mediated by dysfunctional ion channels and glutamate receptors expressed on CNS neurons. Thus riluzole's mechanism of action could be relevant in treating neuropathic SCI pain. The current study evaluated the antinociceptive potential of riluzole in rats following a SCI. Four weeks after a brief compressive injury to the mid-thoracic spinal cord, rats displayed significantly decreased hind paw withdrawal thresholds, suggestive of below-level cutaneous hypersensitivity. A single systemic dose of riluzole (8?mg/kg) injected intraperitoneally (i.p.) reversed cutaneous hypersensitivity in SCI rats. To identify riluzole's CNS site of action, riluzole was injected intrathecally (i.t.) and intracerebroventricularly (i.c.v.) in SCI rats. Significant antinociceptive effects were obtained following i.c.v., but not i.t., injection. Systemic riluzole was also antinociceptive in uninjured rats, increasing the latency to respond to an acute noxious thermal stimulus in the tail flick test. Unlike in SCI rats, however, riluzole was not effective when administered directly into the CNS, indicating a peripherally mediated antinociceptive mechanism. Although riluzole appears to have a general antinociceptive effect, the site of action may be model dependent. In total, these data indicate that riluzole may be an effective clinical analgesic for the treatment of below-level neuropathic SCI pain. Although the exact mechanism of action is not clear, there is a predominant supraspinal component of riluzole-induced antinociception in SCI rats.     

鞘内注射KN93对小鼠神经病理性疼痛的镇痛效应

目的 探讨钙离子/钙调蛋白依赖蛋白激酶Ⅱ(CaMKⅡ)在神经病理性疼痛发病机制中的作崩.方法 雄性ICR小鼠32只,随机均分为四组:神经病理性疼痛(SNL)组,制作L5/6脊神经结扎(SNL)模型;SNL/KN92组,制作SNL模型,鞘内注射无药理活性的KN93的结构类似物KN92 45 nmol;SNL/KN93组,制作SNL模型,鞘内注射KN93 45 nmol;假手术(Sham)组,仅显露脊神经而小结扎.分别于SNL术前及术后2～5 d每天测定小鼠的机械痛阈和热痛阈,SNL/KN92组与SNL/KN93组于术后5 d痛阈测定前30 min行鞘内给药.于最后一次痛阈测定毕处死小鼠,取腰段脊髓组织用Western blot检测pCaMK Ⅱα的表达水平.结果 SNL可导致机械痛阈和热痛阈降低(P<0.05),脊髓组织pCaMKⅡα的表达增加(P<0.05);鞘内注射KN93可翻转SNL所致的上述改变(P<0.05),但KN92无此效应.结论 CaMK Ⅱ参与了SNL诱导的神经病理性疼痛的维持,靶向于CaMK Ⅱ信号途径的治疗町为慢性疼痛治疗提供新的策略.     

The effect of intrathecal magnesium sulphate on nociception in rat acute pain models

We examined the antinociceptive effect of intrathecally administered magnesium sulphate (MgSO4) in rats, using acute pain models including mechanical pressure, heat and subcutaneous formalin injection. According to the locomotion test 10 microliters of 6.2% MgSO4 did not produce motor paralysis. At the same dose, responses to pressure and heat were intact, compared with controls given saline. MgSO4 produced depression of pain responses only after the first 10 min in the formalin test. Our studies indicated that MgSO4 did not show remarkable antinociceptive effects in acute pain models.     

Treatment of neuropathic cancer pain with continuous intrathecal administration of S +-ketamine

The effective treatment of patients suffering from neuropathic cancer pain remains a clinical challenge. When patients experience either insufficient analgesia or problematic side-effects after opioid administration, intrathecal administration of morphine and other medications such as bupivacaine and clonidine may offer significant advantages. Additionally, ketamine, a non-competitive N-methyl-D-Aspartate-receptor antagonist is able to alter pain perception at the spinal level. Because of the potential neurotoxicity after neuraxial use of racemic ketamine, intrathecal administration of the preservative-free active compound, S (+)-ketamine may be a valuable alternative. In this paper, we present a patient with severe neuropathic cancer pain successfully treated by continuous intrathecal infusion of morphine, bupivacaine, clonidine and S (+)-ketamine. Moreover, quality of life measurements before and 3 weeks after the start of spinal treatment revealed an improvement in pain relief and a higher overall quality of life. No clinical signs of neurologic deficit were observed during spinal treatment with S (+)-ketamine. However, the continuous intrathecal administration of S (+)-ketamine should be considered as the last resort because there are no preclinical safety data with relevant concentrations on intrathecal use of S (+)-ketamine.     

Antinociceptive and neurotoxicologic screening of chronic intrathecal administration of ketorolac tromethamine in the rat

Many drugs are tested intrathecally to investigate alternatives to opioids. We aimed to explore the analgesic and possible neurotoxic effects of chronic intrathecally-administered ketorolac tromethamine in rats. Catheters were placed via atlantoaxial interval in 28 Wistar rats under anesthesia of intraperitoneally-injected thiopental 30 mg/kg. Rats were randomized into 4 groups and administered 4 repeated intrathecal doses of therapy with 5-day intervals. The control group received 10 microL of saline, and the other groups received 50, 150, and 400 microg of ketorolac tromethamine respectively. The formalin test, behavioral test, and histopathological examination of four different spinal cord levels were performed. Neither behavioral testing nor histopathological examination revealed abnormalities that would suggest neurotoxicity. Formalin tests showed that both phase I and phase II responses of ketorolac tromethamine groups were significantly less than those of the control group. Although phase I responses did not differ during comparisons among ketorolac tromethamine-administered groups, phase II responses decreased significantly in groups that received 150 and 400 microg of ketorolac tromethamine. Intrathecally administered ketorolac tromethamine reduced nociceptive responses and exhibited no untoward neurological effect even at large doses. However, its intrathecal use as a safe alternative drug for chronic pain remains to be investigated in other species. IMPLICATIONS: The present study is unique because it has demonstrated that chronic intrathecal administration of ketorolac tromethamine in rats, even at considerably large doses, showed a potent analgesic effect during the formalin test without exhibiting any neurotoxic side effect.     

鞘内注射反义蛋白激酶Cγ寡核苷酸对慢性神经痛大鼠的镇痛作用

目的 探讨鞘内注射反义、正义PKCγ寡核苷酸(PKCγ-ASODN、PKCγ-SODN)对慢性神经痛大鼠的镇痛作用及其机制。方法 24只雌性SD大鼠建立慢性坐骨神经痛(CCI)模型,鞘内置管后随机分为4组:CCI 无菌生理盐水鞘内注射组(C组);CCI PKCγ-SODN 20μg鞘内注射组(S组);CCI PKCγ-ASODN 5μg鞘内注射组(A1组);CCI PKCγ-ASODN 20μg鞘内注射组(A2组),每组6只。除C组外,其余三组均于鞘内注入相应剂量的PKC7γ-SODN或-ASODN,每日1次,连续6 d,采用VonFrev hairs检测术侧机械缩爪阈值变化,Western blot法检测脊髓PKCγ、PKCα蛋白质表达。结果 与结扎术前比较,机械缩爪阈值S组注药后2、4、6 d降低,A1组注药后2 d天降低(P<0.01),A2组注药后4 d升高(P<0.05或0.01);与C组比较,A1组注药后4、6d及A2组注药后2、4、6 d升高(P<0.01);与A1组比较,A2组注药后2、4 d升高(P<0.01)。与C组比较,A1、A2组PKCγ蛋白质表达丰度降低(P<0.01),而S组PKCγ蛋白质及S、A1、A2组PKCα蛋白质表达丰度差异无统计学意义(P>0.05)。结论　鞘内注射PKCγ-ASODN可抑制慢性神经痛大鼠的痛觉过敏,该作用与PKCγ蛋白质活性降低,表达量下调有关。     

鞘内注射人β-内啡肽基因重组腺病毒对慢性神经病理痛大鼠的镇痛作用

目的观察鞘内注射入β-内啡肽(β-EP)基因重组腺病毒(Ad-NEP)对慢性神经病理痛大鼠的镇痛作用。方法36只雄性SD大鼠,体重210-260 g,随机分为手术组(n=26)、假手术组(n= 5)、空白对照组(n=5),手术组分为三个亚组:Ad-NEP组(n=9)、绿色荧光蛋白基因重组腺病毒(Ad- GFP)组(n=9)、生理盐水组(n=8)。大鼠腹腔注射氯胺酮100 mg/kg和阿托品50 mg/kg麻醉后,手术组构建大鼠坐骨神经慢性捆扎(CCI)模型,假手术组进行同样手术,但不捆扎坐骨神经,空白对照组不进行手术;手术组经L5,6间隙蛛网膜下腔置入PE-10导管,7d后分别注射1×108pfu的Ad-NEP、Ad- GFP和40μl生理盐水。于手术后7 d(T0)、鞘内注射前当日(T1)、注射后1 d(T2)、1周(T3)、2周(T4)、3 周(T5)、4周(T6)、5周(T7)分别测定五组大鼠的左右足热痛阈;T3时取Ad-NEP、Ad-GFP组大鼠各1 只,取脊髓L3-6段作免疫组化检测;鞘内注射后10 d取Ad-NEP、Ad-GFP组大鼠,经腹腔内注射1 mg/kg 纳络酮,每间隔10min记录右足热痛阈(t0-9,共观察90min),并分别测定这两组T1-7时的脑脊液内β- EP浓度。结果Ad-GFP组和生理盐水组大鼠右足热痛阈明显低于假手术组和空白对照组(P< 0.01)。Ad-NEP组在T0,1,7时右足热痛阈明显低于假手术组和空白对照组(P<0.01),在T2-6时的右足热痛阈高于T0,也高于Ad-GFP组和生理盐水组(P<0.05或0.01),t1-6时右足热痛阈低于t0时(P< 0.01),与Ad-GFP组和生理盐水组比较差异无统计学意义(P>0.05)。Ad-NEP组脊髓外膜可见明显的橙黄色浓染带,后角区可见少量橙黄色细胞,T2-7时脑脊液内β-EP浓度均高于Ad-GFP组(P< 0.01。)结论鞘内注射重组腺病毒Ad-NEP对慢性神经病理痛大鼠有明显的镇痛效果,作用时间长达4周以上。     

Antinociceptive effect of intracerebroventricular administration of d-serine on formalin-induced pain

Purpose

In a previous study using the tail-flick test, we found that intracerebroventricular administration of d-serine, an endogenous co-agonist at the glycine sites of N-methyl-d-aspartate (NMDA) receptors, elicited an antinociceptive effect on thermal nociception. The purpose of the present study was to evaluate the effect of intracerebroventricular administration of d-serine on nociception induced by tissue damage or inflammation using the formalin test.

Methods

Infusion of drugs into the third ventricle in rat was performed via indwelling cannulae. Drugs were infused at a volume of 10 μl over 2 min, and the infusion cannula was left in place for 2 min before removal. The formalin test was performed 10 min after drug administration.

Results

Intracerebroventricular administration of d-serine significantly and dose-dependently decreased the number of flinches in both the early and late phases in the formalin test. This antinociceptive effect was antagonized by intracerebroventricular administration of L-701,324, a selective antagonist at the glycine sites of NMDA receptors.

Conclusion

The present data suggest that activation of NMDA receptors via glycine sites at the supraspinal level induces an antinociceptive effect on both acute and tonic pain.     

鞘内预注L-NAME对神经痛大鼠脊髓内c-fos基因表达的影响

目的 观察鞘内预先应用非选择性NOS抑制剂——L-NAME对结扎坐骨神经所致神经痛大鼠脊髓背角内c-fos基因表达的影响。方法 选择鞘内置管后无神经损伤症状的SD雌性大鼠84只,随机分为4组。A组:假手术组(n=16);B组:坐骨神经结扎组(n=24);C组:假手术前15min鞘内注射L-NAME 10μl(250μg)(n=16);D组:坐骨神经结扎前15min鞘内注射L-NAME 10μl(250μg)(n=24)。各组动物均再随机平均分为4个亚组,术后分别存活1d、3d、7d和14d。另有4只没有接受任何手术的大鼠处死后作为对照。用免疫组织化学方法观察各组大鼠同侧脊髓背角内c-fos基因的表达情况。结果 与对照组相比,在术后各测量时间点A、B两组大鼠同侧脊髓背角内c-fos基因的表达均明显增强,其中以B组最为明显(P<0.05)。鞘内预注L-NAME可明显抑制结扎坐骨神经所诱导的大鼠同侧脊髓背角内c-fos基因的表达,使D组大鼠同侧脊髓背角内Fos阳性细胞的数目在术后第3d、7d和14d分别较B组下降53.8％、57.1％和43.2％(P<0.05),但A组和C组大鼠同侧脊髓背角内Fos阳性细胞的数目没有差异。结论 一氧化氮是介导神经痛发生的一种重要介质,鞘内预先应用L-NAME可有效减少或预防神经痛的发生。     

鞘内转染重组腺病毒介导入神经生长因子β基因对神经病理性痛大鼠的镇痛作用

目的评价鞘内转染重组腺病毒介导人神经生长因子β（Ad-hNGFβ）基因对神经病理性痛大鼠的镇痛作用。方法雄性SD大鼠96只,体重200～250 g,随机分为3组（n=32）,假手术组（Ⅰ组）假手术后立即鞘内注射人工脑脊液;Ⅱ组和Ⅲ组制备坐骨神经慢性压迫性损伤（CCI）模型,术后分别立即鞘内注射人工脑脊液或Ad-hNGFβ基因。分别于术前1d（基础值）和转染后4～28 d每4天测定整体行为学评分、机械痛阈和热痛阈;每组分别于转染后4、7、14及28 d各处死8只大鼠,取脊髓组织,每个时点的4个标本用于测定hNGFβ表达（免疫组化方法）,每个时点的另外4个标本用于测定hNGFβ的含量（ELISA法）。结果Ⅲ组脊髓出现hNGFβ表达;Ⅲ组脊髓hNGFβ含量高于Ⅰ组和Ⅱ组（P〈0.01）;与Ⅰ组比较,Ⅱ组和Ⅲ组行为学评分升高,机械痛阈及热痛阈均降低（P〈0.05或0.01）;与Ⅱ组比较,Ⅲ组行为学评分及机械痛阈差异无统计学意义（P〉0.05）,转染后8～24 d热痛阈升高（P〈0.05）。结论CCI诱导的慢性神经病理性痛大鼠鞘内转染Ad-hNGFβ基因后,可在脊髓组织持续、高效表达,且能减轻热痛觉过敏,但对机械痛觉过敏无影响。     

鞘内预注射L-NAME对神经性疼痛大鼠脊髓背角降钙素基因相关肽表达的影响

目的 观察鞘内预注射NG-硝基-L-精氨酸-甲基酯(L-NAME)对结扎坐骨神经所致神经性疼痛大鼠脊髓背角降钙素基因相关肽(CGRP)表达的影响。方法 选择鞘内置管后无神经损伤症状的SD雌性大鼠96只,随机分为4组,每组24只。A组:假手术组;B组:坐骨神经结扎组;C组:假手术前15 min鞘内注射L-NAME 10 μl(250 μg);D组:坐骨神经结扎前15 min鞘内注射L-NAME 10 μl(250 μg)。各组分别在术后第1、4、7和14天随机处死6只大鼠。采用免疫组织化学方法观察各组大鼠结扎侧脊髓背角CGRP的表达。结果 与A组比较,B组、D组大鼠结扎侧脊髓背角CGRP表达在术后第4、7和14天明显升高(P<0.05),C组差异无显著性。与C组比较,D组大鼠结扎侧脊髓背角CGRP表达在术后第4、7和14天明显升高(P<0.05)。而D组大鼠结扎侧脊髓背角内的CGRP表达与B组比较,差异无显著性(P>0.05)。结论 鞘内预注射L-NAME不能抑制周围神经损伤所诱导的脊髓背角CGRP表达,提示一氧化氮介导神经性疼痛的作用不是通过促进CGRP释放实现的。     

鞘内注射P300 siRNA对神经病理性痛大鼠的镇痛效果

目的 评价鞘内注射p300小干扰RNA(p300siRNA)对神经病理性痛大鼠的镇痛效果.方法 取鞘内置管成功的雄性SD大鼠96只,采用坐骨神经慢性压迫性损伤法(CCI)建立神经病理性痛模型,随机分为4组(n=24):假手术+生理盐水组(S组)、CCI+生理盐水组(CCI组)、CCI+转染试剂组(V组)和CCI+p300siRNA组(P组).于术后3～6 d时鞘内注射生理盐水、转染试剂或p300siRNA(siRNA 4μg溶于转染试剂)各20μl,2次/d,10μl/次,连续4 d.于术前1 d(基础状态)、术后1、3、5、7、9、11、14 d时测定机械痛阈和热痛阈;于术后3、7、14 d时取腰段脊髓,测定p300蛋白及其mRNA、乙酰化组蛋白H3(Ac-H3)的表达.结果 与基础值比较,CCI组、V组和P组术后各时点机械痛阈和热痛阈降低(P＜0.05).与S组比较,其余各组机械痛阈和热痛阈降低,p300蛋白及其mRNA和Ac-H3蛋白表达上调(P＜0.05).与CCI组比较,P组机械痛阈和热痛阈升高,p300蛋白及其mRNA和Ac-H3蛋白表达下调(P＜0.05).结论 鞘内注射p300 siRNA可减轻大鼠神经病理性痛,其机制与抑制脊髓p300和Ac-H3蛋白的表达有关.     

Antiallodynic effect of intrathecal neostigmine is mediated by spinal nitric oxide in a rat model of diabetic neuropathic pain

BACKGROUND: Intrathecal administration of acetylcholinesterase inhibitors produces antinociception in both animals and humans, but their effect on diabetic neuropathic pain has not been studied. In the current study, we determined the antiallodynic effect of intrathecal injection of an acetylcholinesterase inhibitor, neostigmine, in a rat model of diabetic neuropathic pain. In addition, since acetylcholine can increase release of nitric oxide in the spinal cord, we studied the role of spinal endogenous nitric oxide in the action of intrathecal neostigmine in diabetic neuropathic pain. METHODS: Rats were rendered diabetic with an intraperitoneal 50-mg/kg injection of streptozotocin. Intrathecal catheters were inserted, with tips in the lumbar intrathecal space. Mechanical allodynia was determined by application of von Frey filaments to the hind paw. We first determined the dose-dependent effect of intrathecal neostigmine on allodynia. The role of spinal nitric oxide in the action of intrathecal neostigmine was then examined through intrathecal treatments with a neuronal nitric oxide synthase inhibitor (TRIM), a nitric oxide scavenger (PTIO), L-arginine, or D-arginine. RESULTS: The diabetic rats developed a sustained tactile allodynia within 4 weeks after streptozotocin injection. Intrathecal injection of 0.1-0.5 microg neostigmine dose-dependently increased the withdrawal threshold in response to application of von Frey filaments. Intrathecal pretreatment with 30 microg TRIM or 30 microg PTIO abolished the antiallodynic effect of intrathecal neostigmine. Furthermore, the inhibitory effect of TRIM on the action of intrathecal neostigmine was reversed by intrathecal injection of 100 microg L-arginine but not D-arginine. CONCLUSIONS: Intrathecal neostigmine produces a profound analgesic effect in a rat model of diabetic neuropathic pain. Spinal endogenous nitric oxide contributes to the analgesic action of intrathecal neostigmine in this rat model of diabetic neuropathic pain.     

鞘内注射Roscovitine对小鼠骨癌痛行为学的影响

目的 探讨鞘内给予细胞周期依赖性激酶5(cyclin-dependent kinases,Cdk5)特异性拮抗剂Roscovitine对小鼠骨癌痛行为学的影响.方法 24只C3H/Hej 小鼠采用随机数字表法随机分为3组,S组(假手术后14 d+溶媒)、C组(接种后14d+溶媒)、R组(接种后14 d+Roscovitine),每组8只.C组和R组将含2×105个纤维肉瘤NCTC 2472细胞的最小必需培养基(α-MEM)20μl注射到小鼠右侧股骨远端骨髓腔内,制作骨癌痛模型.S组只注入不含肿瘤细胞的α-MEM.术后14 d,R组小鼠鞘内注射含有20μg Roscovitine的二甲基亚砜(DMSO)5μl,C组及S组小鼠鞘内注DMSO 5 μl.观察给药前及给药后1、6、24、48、72 h检测小鼠痛行为学的变化:机械缩足阈值(paw uithdrawal mechanical threshold,PMWT)和热缩足潜伏期(Paw withdrawal thermal latency,PWTL).结果 各组术前基础机械缩足阈值及热缩足潜伏期比较差异无统计学意义(P＞0.05).接种后7 d,C组PMWT(1.08±0.24)g,与S组(1.85±0.28)g相比明显降低(P＜0.05);接种后10 d,C组PTWL(12.7±1.4)s较S组(18.6±2.1)s明显缩短(P＜0.05),C组小鼠的痛行为学随时间逐渐加重,与S组小鼠比较差异有统计学意义(P＜0.05);与C组及给药前基础值相比,鞘内注射Roscovitine 20μg后6 h PMWT(0.70±0.19)g显著增加(P＜0.05),PTWL(14.16±1.07)s显著延长(P＜0.05),并随时间逐渐增加,12 h达最大值,后逐渐降低,72 h降低到C组水平.结论 鞘内注射Roscovitine可有效缓解小鼠骨癌痛.     

蛛网膜下腔注射氯胺酮对神经痛大鼠痛行为的影响

目的 观察蛛网膜下腔应用氯胺酮对慢性压迫性损伤所致的神经痛大鼠行为的影响。方法 SD雄性大鼠40只制备慢性神经痛模型,随机分为四组,每只大鼠蛛网膜下腔注射5μl成分不同的液体。A组：神经结扎前30min及术后3d每天蛛网膜下腔注射氯胺酮5μg,B组：神经结扎前30min及术后3d每天蛛网膜下腔注射氯胺酮50μg,C组：神经结扎术后4d蛛网膜下腔注射氯胺酮50μg,D组：对照组,神经结扎前30min及术后4d每天注入人工脑脊液。神经结扎术后第7d,所有动物腹腔内注射亚镇痛量的芬太尼0．2μg。自神经结扎术前1d起至术后10d每天观察大鼠热痛阈和自发痛行为的变化。结果 A、B两组痛行为均明显轻于D组（P＜0．05）,且维持至停药后较长时间,C组用药后痛行为减轻（P＜0．05）,但维持时间短,A、B两组较C、D两组能显著提高亚镇痛量芬太尼的镇痛作用（P＜0．05）。A、B两组间无显著性差异（P＞0．05）。结论 蛛网膜下应用氯胺酮可有效地防治神经痛,并加强亚镇痛量的芬太尼的镇痛作用。     

Allodynia after acute intrathecal morphine administration in a patient with neuropathic pain after spinal cord injury

IMPLICATIONS: Acute intrathecal administration of relatively small doses of opioids may precipitate neuropathic pain and allodynia in those with spinal cord injury.