雷公藤内酯醇(T10)通过抑制脊髓背角内p38-MAPK的磷酸化发挥镇痛作用的机制研究

目的:观察鞘内给予雷公藤内酯(triptolide,T10)对于慢性炎性痛和神经病理性痛模型大鼠脊髓背角小胶质细胞内p38丝裂原激活的蛋白激酶(p38 mitogen-activated protein kinase,MAPK)的磷酸化水平的影响。方法:采用大鼠足底注射完全弗式佐剂(complete Freund’s adjuvant,CFA)构建慢性炎性痛模型,L5脊神经结扎(spinal nerve ligation,SNL)和坐骨神经分支选择性结扎(spared nerve injury,SNI)的方法制作慢性神经病理性痛模型。利用von Frey丝刺激法连续观察造模后大鼠的痛行为变化;应用免疫荧光染色方法观察大鼠腰膨大节段胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和电离钙绑定衔接分子1(ionized calcium binding adaptor molecule-1,Iba-1)的表达水平;应用Western Blot方法观察大鼠腰膨大节段p38 MAPK的磷酸化水平。结果:(1)行为学结果显示:CFA、SNL、SNI模型大鼠机械性痛阈均明显降低,且术后一周内与正常对照组相比均保持在较低水平(P0.01)。从术后第1 d起鞘内连续给予T10至第7 d,分别观察到T10能够明显提高上述模型大鼠手术侧后足的机械性痛阈(P0.05);但T10在SNL模型和SNI模型大鼠中的效果要弱于CFA引起的慢性炎性痛(P0.05)。(2)免疫荧光染色结果显示:CFA、SNL和SNI模型大鼠腰膨大脊髓背角内GFAP、Iba-1的表达明显高于正常对照组,而p-p38 MAPK阳性产物主要表达于小胶质细胞内。(3)Western Blot结果显示:造模后7 d脊髓背角内p-p38 MAPK的表达明显上调,鞘内给予T10后可以显著下调脊髓背角内p38的磷酸化水平(P0.05)。结论:鞘内给予T10有效缓解由于CFA、SNL和SNI诱导的慢性痛模型大鼠的机械性痛阈的机制可能是通过下调脊髓背角内p38 MAPK信号通路的磷酸化水平,进而达到抑制小胶质细胞和星形胶质细胞的活化。其次,T10对不同类型的疼痛模型的作用效果存在差异,对由CFA引起的慢性炎性痛的作用效果要强于由SNL和SNI诱导的慢性神经病理性痛。     

鞘内给予氯胺酮通过抑制星形胶质细胞内STAT3的磷酸化改善大鼠神经病理性痛的研究

目的:观察神经病理性痛大鼠鞘内给予氯胺酮对于脊髓背角星形胶质细胞内信号转导和转录活化因子3(STAT3)磷酸化水平的影响。方法:采用L5脊神经结扎(SNL)方法制作慢性神经病理性痛模型,利用机械刺激法和热板法连续观察造模后大鼠的痛行为变化;应用免疫组织化学染色和Western Blot方法观察大鼠腰膨大节段胶质纤维酸性蛋白(GFAP)和磷酸化STAT3(pSTAT3)的表达水平。结果:SNL模型大鼠机械性痛阈和热痛阈均明显降低,且术后一周内均保持在较低的水平(P0.01),从术后第3 d起鞘内连续给予氯胺酮至第7 d能够明显缓解大鼠患侧后爪的机械性痛敏和热痛敏。免疫荧光组织化学染色显示:pSTAT3在星形胶质细胞上有表达,且SNL后pSTAT3与GFAP在脊髓背角的表达均升高。Western Blot结果显示:与对照组相比,SNL后第7 d脊髓背角的pSTAT3的表达明显上调(P0.05),从术后第3 d鞘内连续给予氯胺酮至第7 d能够明显下调STAT3的磷酸化水平。结论:鞘内给予氯胺酮能够明显下调脊髓背角星形胶质细胞内STAT3的磷酸化水平从而达到缓解疼痛的目的。     

石菖蒲挥发油对炎性痛大鼠脊髓背角中胶质纤维酸性蛋白、c-Jun氨基末端蛋白激酶和肿瘤坏死因子α表达的影响

目的 探讨石菖蒲挥发油(VOA)对炎性痛大鼠脊髓背角中胶质纤维酸性蛋白(GFAP)、c-Jun氨基末端蛋白激酶(JNK)和肿瘤坏死因子α(TNF-α)表达的影响。方法 36只雄性SD大鼠随机分为：对照组(control)、假手术组(sham)、完全弗氏佐剂组(CFA)、 5 g/(kg·d)低剂量VOA+CFA组(VOA-L+CFA)、10 g/(kg·d)中剂量VOA+CFA组(VOA-M+CFA)和20 g/(kg·d)高剂量VOA+CFA组(VOA-H+CFA),共6组，每组6只，于连续灌胃给药的第22天取材。利用免疫荧光染色和Western blotting技术检测各组大鼠脊髓背角中GFAP、JNK和TNF-α的表达情况。结果 免疫荧光染色及Western blotting结果表明，与control和sham组相比，CFA组中大鼠脊髓背角中GFAP、JNK和TNF-α阳性表达均显著增多(P<0.01);与CFA组相比，不同剂量VOA处理组大鼠脊髓背角中GFAP、JNK和TNF-α阳性表达均减少，且VOA-H+CFA组大鼠脊髓背角中GFAP、JNK和TNF-α阳性表达减少更...     

脊髓星形胶质细胞通过调控Cx43-JNK通路介导吗啡耐受

目的探讨脊髓星形胶质细胞是否通过调控Cx43-JNK通路介导大鼠慢性吗啡耐受。方法采用SD成年大鼠,连续7 d鞘内注射吗啡(15μg/10μl)建立慢性吗啡镇痛耐受动物模型。采用热水甩尾法测定甩尾潜伏期以观察吗啡的镇痛效果。应用Western blot法检测脊髓Cx43、磷酸化JNK(p-JNK)、磷酸化c-Jun(p-c-Jun)和GFAP的表达;免疫组织荧光染色法检测脊髓GFAP的免疫反应性。结果在吗啡耐受形成的过程中,慢性鞘内注射吗啡引起大鼠脊髓GFAP表达逐渐增多,吗啡耐受时脊髓p-JNK、p-c-Jun和Cx43的表达明显增多;氟代柠檬酸(Fluorocitric acid,1 nmol/10μL)可以拮抗吗啡镇痛耐受,并且明显地抑制慢性吗啡所致的脊髓Cx43的上调,以及JNK及c-Jun的激活。结论脊髓Cx43-JNK通路参与星形胶质细胞介导的大鼠慢性吗啡镇痛耐受。     

星形胶质细胞在糖皮质激素诱发糖尿病神经病理性痛中的作用

目的探讨星形胶质细胞在糖皮质激素诱发糖尿病神经病理性痛中的作用及可能的机制。方法利用链脲佐菌素诱导SD大鼠糖尿病模型,鞘内置管。实验分3组,对照组,糖尿病组(不给予RU486,糖皮质激素受体阻断剂),RU486组(糖尿病大鼠鞘内注射RU486)。4周后检测大鼠血糖及痛阈变化,免疫组化检测脊髓背角星形胶质细胞形态学变化,Western blot检测胶质纤维酸性蛋白(GFAP,星形胶质细胞活性标志物)及磷酸化Jun氨基末端激酶(p-JNK)表达变化。结果与对照组相比,糖尿病组及RU486组大鼠血糖显著升高(0.01)P,糖尿病组脊髓背角星形胶质细胞胞体增大、突起延长,明显活化,而RU486组变化不明显。与对照组相比,糖尿病组痛阈降低,GFAP及p-JNK在脊髓表达减少(均0.01),RU48P6组接近对照组(P0.05)。结论 P糖皮质激素通过血糖非依赖机制活化星形胶质细胞,激活JNK信号通路参与DNP的发生。     

内质网应激介导的JNK通路在大鼠神经病理性疼痛中的作用

目的:检测内质网应激介导的JNK通路在坐骨神经慢性压迫(CCI)模型大鼠中的作用。方法:SD雄性大鼠随机分为假手术组(sham)和模型组(CCI)。CCI前、后1、3、5、7、14 d测定大鼠的热痛敏和机械痛敏;CCI后14 d,免疫组织化学检测大鼠脊髓背角内葡萄糖调节蛋白78(GRP78)、p-JNK、caspase-3和胶质纤维酸性蛋白(GFAP)的表达;TUNEL法检测脊髓背角内的细胞凋亡。结果:与假手术组相比,模型组的热痛敏和机械痛敏在术后均明显下降,脊髓背角内GRP78、p-JNK、caspase-3和GFAP的表达均增高,凋亡染色阳性细胞数目也较多。结论:内质网应激介导的p-JNK途径参与了神经病理性疼痛模型大鼠脊髓背角内神经元凋亡,可能与星形胶质细胞的活化有关。     

皮质酮对大鼠脊髓背角星形胶质细胞活动的影响

目的:探讨皮质酮(corticosterone,CORT)对培养的大鼠脊髓背角星形胶质细胞活性的调节作用。方法:培养纯化新生SD大鼠脊髓背角星形胶质细胞,荧光双重标记技术检测培养的星形胶质细胞糖皮质激素受体(glucocorticoid receptor,GR)及胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)共表达;免疫印迹技术检测星形胶质细胞GFAP表达的变化;高效液相色谱法(high performance liquid chromatography,HPLC)检测星形胶质细培养液中谷氨酸含量。结果:培养的脊髓背角星形胶质细胞均表达GR;CORT孵育3 h可降低脊髓背角星形胶质细胞GFAP表达,GR拮抗剂RU38486可阻断CORT的作用;但CORT对星形胶质细胞谷氨酸释放无显著影响。结论:CORT可降低脊髓背角星形胶质细胞GFAP表达,但对谷氨酸释放无显著影响。     

脊髓背角星形胶质细胞内PAPR-1/TNF-α通路参与脊神经结扎模型大鼠神经病理性痛的机制研究

目的观察PAPR-1/TNF-α信号通路在脊神经结扎模型大鼠脊髓背角星形胶质细胞内的表达情况,并探究其与神经病理性痛的发生发展关系。方法将大鼠第5腰神经(L5)进行结扎构建慢性神经病理性痛模型,Von-Frey细丝检测各组大鼠的机械性痛阈值,免疫组织化学染色和Western blot技术半定量和定量分析脊髓背角内PAPR-1和TNF-α的表达情况。结果与正常组相比,假手术组大鼠疼痛阈值未见显著改变(P0.05),脊神经结扎后大鼠的术侧后足的疼痛阈值显著降低,差异具有统计学意义(P0.05),且在术后2周内,疼痛阈值均保持在较低水平。免疫荧光组织化学染色结果显示,PAPR-1和TNF-α主要表达于脊髓背角内星形胶质细胞中,Western blot结果进一步显示,造模后大鼠脊髓背角内GFAP、PAPR-1及TNF-α水平显著高于正常组和假手术组(P0.05)。结论 PAPR-1/TNF-α信号通路主要表达于脊髓背角内星形胶质细胞中,且在慢性神经病理性痛的维持阶段保持较高表达水平,可能参与了慢性痛的发生和发展,临床治疗中具有一定的理论参考意义。     

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。     

绞股蓝皂苷缓解大鼠三叉神经痛及其机制研究

目的:观察绞股蓝皂甙(GP)对SD大鼠三叉神经神经病理性痛(NP)的镇痛效果,并对其机制进行探索。方法:制备三叉神经NP模型大鼠,分为单纯手术及低剂量、高剂量绞股蓝皂甙治疗组以及假手术组对照,对比四组大鼠口面部机械痛敏阈值。脑干切片行胶质纤维酸性蛋白(GFAP)免疫荧光分析,计算GFAP荧光相对光密度值;利用Western Blot法分析计算三叉神经脊束核尾侧亚核(Vc)中GFAP及磷酸化JNK(pJNK)蛋白含量相对比值。结果:GP可以有效缓解模型导致的大鼠三叉神经NP;同时可显著下调Vc中星形胶质细胞活化及JNK(Jun N-terminal kinase)激酶表达。结论:GP可有效缓解大鼠三叉神经NP,此效应与其抑制Vc中星形胶质细胞和JNK通路的激活密切相关。     

Brain-derived neurotrophic factor–activated astrocytes produce mechanical allodynia in neuropathic pain

Neuropathic pain management is challenging for physicians and a vexing problem for basic researchers. Recent studies reveal that activated spinal astrocytes may play a vital role in nerve injury-induced neuropathic pain, although the mechanisms are not fully understood. We have found increased glial fibrillary acidic protein (GFAP) expression, a hallmark of reactive gliosis, and elevated brain-derived neurotrophic factor (BDNF) expression in the dorsal horn in a rat model of allodynia induced by spinal nerve ligation (SNL). The high GFAP expression and mechanical allodynia that SNL induces were prevented by the intrathecal injection of the BDNF-sequestering fusion protein TrkB/Fc. Additionally, mechanical allodynia and GFAP overexpression was induced by the spinal administration of exogenous BDNF to naive rats, and exogenous BDNF given together with fluorocitrate, an astrocytic metabolism inhibitor, inhibited allodynia and GFAP upregulation. Exogenous BDNF also activated the astrocytes directly when tested in vitro. Furthermore, intrathecal administration of BDNF-stimulated astrocytes also induced mechanical allodynia in naive rats. All of these results indicate that astrocytes activated by BDNF might contribute to mechanical allodynia development in neuropathic pain in rats.     

腹膜腔给予SAHA通过上调大麻素受体1的表达改善大鼠骨癌痛的研究

目的:观察腹膜腔给予辛二酰苯胺异羟肟酸(suberoylanilide hydroxamic acid,SAHA)对于骨癌痛(cancer-induced bone pain,CIBP)模型大鼠脊髓背角内大麻素受体1(cannabinoid-like receptor 1,CB1R)表达的影响。方法:将健康雌性SD大鼠随机分为4组:Sham+saline组、CIBP 7 d+saline组、CIBP 14 d+saline组、CIBP 14d+SAHA组。后三组动物胫骨内注射Walker 256乳腺癌肿瘤细胞制作骨癌痛模型。CIBP+SAHA组术后第1 d开始每日连续腹膜腔给予50 mg/kg SAHA至第14 d。利用机械刺激法连续观察各组大鼠的痛行为变化。应用免疫组织化学染色和Western Blot方法观察大鼠腰膨大节段脊髓背角内CB1R的表达情况。结果:自术后第7 d开始,与假手术组相比,CIBP组大鼠机械性缩足阈值(paw withdrawal threshold,PWT)明显下降(P0.01),这种变化一直持续到至少术后第14 d。从术后第1~14 d连续腹膜腔内给予SAHA能明显缓解大鼠机械性痛敏(P0.05)。免疫荧光组织化学染色显示:CB1R主要表达于脊髓背角浅层,CIBP组大鼠脊髓内CB1R表达上调,而腹膜腔内给予SAHA后可进一步促进脊髓背角内CB1R的上调。Western Blot结果显示:与对照组相比,造模后第7d和14 d脊髓背角内CB1R表达上调(P0.05)。与骨癌痛相比,从术后第1~14 d连续腹膜腔给予SAHA能明显促进脊髓背角内CB1R的表达(P0.05)。结论:在骨癌痛状态下,大鼠脊髓背角内CB1R表达增加,可能与体内内源性镇痛系统的激活有关,但此时与对照组相比,上调的CB1R不足以发挥镇痛效果;而腹膜腔内给予SAHA后,脊髓背角内CB1R受体表达进一步上调,从而发挥其镇痛效果。     

Effect of chronic inflammation on dorsal horn nociceptive neurons in aged rats

To elucidate the effect of chronic inflammation on spinal nociceptive neurons in the elderly, we compared nocifensive behavior, peripheral inflammatory responses, and spinal dorsal horn neuronal activities between the aged (29-34 mo) and adult (7-12 mo) male rats after injection of complete Freund's adjuvant (CFA) into the hind paw. Aged rats exhibited a significantly lower mechanical paw withdrawal threshold before inflammation. However, after CFA injection mechanical allodynia developed in both adult and aged rats after CFA injection. The changes of foot temperature and thickness after CFA injection were greater and lasted longer in aged than in adult rats. Sets of 124 wide dynamic range (WDR) neurons (aged: 59, adult: 65) and 26 nociceptive specific (NS) neurons (aged: 13, adult: 13) were recorded from the lumber spinal dorsal horn. NS neurons from the inflamed adult rats showed significantly higher responses to noxious mechanical stimulation than those in aged rats, whereas WDR neurons from inflamed adult and aged rats were similar. Background activity of WDR neurons from the adult rats increased after CFA, whereas WDR neurons of aged rats and NS neurons from either group were not. The afterdischarge followed by noxious mechanical stimulation was significantly greater for WDR neurons in both adult and aged rats, whereas no significant differences were observed in NS neurons. Two days after CFA injection, Fos expression increased similarly in aged and adult rats. Thus the aged rats showed enhanced peripheral inflammatory responses to CFA injection with only a slight change in dorsal horn neuronal activity. Together with our previous finding that nociceptive neurons in aged rats exhibit hyperexcitability, these results suggest that the dorsal horn nociceptive system becomes sensitized with advancing age and its excitability cannot be further increased by inflammation.     

Inflammatory pain-induced signaling events following a conditional deletion of the N-methyl-D-aspartate receptor in spinal cord dorsal horn

The N-methyl-d-aspartate (NMDA) receptor in the spinal cord dorsal horn (SCDH) is one of the mechanisms involved in central sensitization during chronic pain. Previously, this laboratory created a spatio-temporal knockout (KO) of the N-methyl-d-aspartate receptor I (NR1) subunit in the mouse SCDH. The NR1 KO completely blocks NR1 gene and subsequent NMDA receptor expression and function in SCDH neurons. In the NR1 KO mice, the mechanical and cold allodynia induced at 24 h after complete Freund's adjuvant (CFA) was reduced. However, the protective effects of KO were transient and were not seen at 48 h after CFA. These observations suggest the presence of NMDA-independent pathways that contribute to CFA-induced pain. CFA induces the activation of several signaling cascades in the SCDH, including protein kinase C (PKC)γ and extracellular signal-regulated kinases (ERK1/2). The phosphorylation of PKCγ and ERK1/2 was inhibited in the SCDH of NR1 KO mice up to 48 h after CFA treatment, suggesting that these pathways are NMDA receptor-dependent. Interestingly, neuronal cyclooxygenase (COX) -2 expression and microglial p38 phosphorylation were induced in the SCDH of the NR1 KO at 48 h after CFA. Our findings provide evidence that inflammatory reactions are responsible for the recurrence of pain after NR1 KO in the SCDH.     

外周炎性痛刺激诱导杏仁核内星形胶质细胞激活及细胞因子的表达

为了观察完全弗氏佐剂(CFA)外周刺激对杏仁核内星形胶质细胞标记物(GFAP)以及细胞因子(IL-β,TNF-α)表达的影响,本研究结合行为学检测、RT-PCR和Westernblot方法,观察了大鼠后爪注射CFA后的痛行为变化,并检测了在不同时间点杏仁核内GFAP、IL-β和TNF-α在基因水平和蛋白水平的表达变化。结果显示:注射CFA后,注射侧后爪出现热痛敏和机械性触诱发痛;大鼠的热痛敏在14d时基本恢复正常,但机械性痛敏持续至21d时仍未恢复正常;GFAP在亚急性期和慢性期有显著增加;而IL-β和TNF-α在急性期、亚急性期及慢性期均有增加。上述结果表明:星形胶质细胞可能与疼痛的维持相关,而细胞因子表达的增加可能在痛觉过敏的产生和维持中均起重要作用。     

Morphine tolerance attenuates the resolution of postoperative pain and enhances spinal microglial p38 and extracellular receptor kinase phosphorylation

Persistent postoperative pain is a very common phenomenon which severely affects the lives of patients who develop it following common surgical procedures. Opioid analgesics are of limited efficacy in the treatment of persistent pain states because of side effects including antinociceptive tolerance. We have previously shown that surgical incision injury and morphine tolerance share similar mechanisms, including a CNS role of spinal cord glia. We therefore hypothesized that prior chronic morphine exposure would inhibit the resolution of postoperative allodynia through increased glial ionized calcium-binding adaptor protein 1 (Iba1) and glial fibrillary acidic protein (GFAP) protein expression and mitogen activated protein kinase (MAPK) activation. To test this hypothesis, rats were implanted with s.c. osmotic minipumps on day zero, releasing saline or morphine for 7 days preceding or 7 days preceding and following paw incision surgery, which was completed on day seven. Thermal hyperalgesia and mechanical allodynia were assessed postoperatively every 3 days. Chronic morphine attenuated the resolution of postoperative thermal hyperalgesia and mechanical allodynia through day 20. However, no changes in Iba1 or GFAP expression were observed in the spinal cord dorsal horn between groups. Assessment of MAPK protein phosphorylation revealed that chronic morphine administration enhanced both p38 and extracellular receptor kinase (pERK) phosphorylation compared to saline on day 20. p-p38 and pERK immunofluorescence were only observed to colocalize with a marker of microglial cells and not with markers of astrocytes or neurons. Together, these data demonstrate that chronic morphine administration attenuates the resolution of postoperative allodynia in association with microglial p38 and extracellular receptor kinase (ERK) phosphorylation, independent of changes in Iba1 and GFAP expression.     

Effects of intrathecal c-fos antisense oligodeoxynucleotide on adjuvant-induced thermal hyperalgesia

We examined the effects of intrathecally preadministered injections of a phosphorothioate analog of c-fos antisense and mismatch oligodeoxynucleotides (ODNs) on the withdrawal latency to a thermal stimulus following unilateral injection of complete Freund's adjuvant (CFA) into the hind footpad of rats. Pretreatment with the c-fos antisense ODN significantly decreased the CFA-induced expression of c-Fos protein dose-dependently in ipsilateral laminae I/II (LI/II) of the dorsal horn (mean ± SEM per section: 10 nM ODN, 43.9±1.3; 25 nM ODN, 19.4±4.1) compared with pretreatment with the mismatch ODN (63.6±2.9; 60.6±4.0) or saline (56.6±5.5). Animals pre-treated with 25 nM of the c-fos antisense ODN significantly increased the withdrawal latency to the noxious thermal stimulation (63.0–70.5%; compared with contralateral to the CFA injection) compared with animals pretreated with mismatch ODN (28.5–42.6%) or saline (26.4–45.3%) from 0 to 5 h after unilateral injection of CFA into the hind footpad. Pretreatment with 10 nM antisense ODN had a less significant effect. These results indicate that the expression of CFA-induced c-Fos in the dorsal horn might facilitate thermal nociception. Electronic Publication     

大鼠外周神经损伤后脊髓背角HMGB1表达上调参与机械性痛觉超敏

目的:研究HMGB1(high mobility group box-1)在神经病理性痛大鼠脊髓水平的表达变化,探索HMGB1在神经病理性痛发生发展中的作用,为治疗神经病理性痛提供新的理论依据和治疗靶点。方法:(1)雄性SD大鼠(180～220)g 12只,随机均分为三组:NS组:鞘内注射生理盐水;A组:鞘内注射HMGB1 1μg;B组:鞘内注射HMGB1 10μg。盲法用von Frey测定给药前及给药后1 h、1、3、7、14、21、28 d大鼠50%机械缩足阈值(me-chanical withdrawal threshold,MWT);(2)雄性SD大鼠(180～220)g 5只,免疫荧光双标观察HMGB1在脊髓背角的表达定位;(3)雄性SD大鼠(180～220)g 42只,随机均分为对照组(6只),SNL模型组(每时间点6只),West-ern Blot方法观察大鼠脊髓背角HMGB1对照及术后1、3、7、14、21、28 d的表达变化。结果:(1)大鼠脊髓鞘内注射HMGB1后诱发长时程机械性痛敏,A组在鞘内给药后7 d MWT明显下降(P<0.01),B组给药后1 h MWT即显著下降,且持续存在至少28 d;(2)免疫荧光双标显示:HMGB1主要表达于NeuN标记的神经元,而GFAP阳性的星形胶质细胞以及OX42阳性的小胶质细胞几乎不表达HMGB1;(3)Western Blot结果显示,脊髓背角HMGB1在SNL模型术后缓慢增高,7 d时增高最为显著,且持续至少28 d。结论:以上结果表明,外周神经损伤后脊髓水平HMGB1的表达上调可能在神经病理性痛的产生和维持中起着重要作用。     

Inflammation of craniofacial muscle induces widespread mechanical allodynia

The modulation of behavioral responses evoked by local and distant nociceptive stimuli following a discrete somatic injection of complete Freund's adjuvant (CFA) was examined in rats. Inflammation of one craniofacial muscle evoked mechanical allodynia not only in the region of inflammation but also secondary mechanical allodynia in the contralateral head, ipsilateral hindpaw, and contralateral hindpaw. In contrast to this, CFA-induced inflammation of either the hindpaw or gastrocnemius muscle evoked mechanical allodynia restricted to the hindlimb region. The widespread modulation of nocifensive behavior evoked by inflammation of deep craniofacial tissue found in this study resembles the widespread deep tissue pain reported in fibromyalgia, whiplash injury and some temporomandibular disorders and thus may provide insight into the mechanisms of these musculoskeletal pathologies.     

石菖蒲挥发油对炎症痛大鼠基底外侧杏仁核中胶质纤维酸性蛋白和即刻早期基因表达的影响

目的 通过注射完全弗氏佐剂(CFA)构建炎症痛大鼠模型,探讨石菖蒲挥发油对炎症痛大鼠基底外侧杏仁核(BLA)中神经胶质纤维酸性蛋白(GFAP)和即刻早期基因(c-fos)表达的影响。方法 成年SD雄性大鼠36只,随机分为6组: 对照（control）组、假手术（sham）组、CFA组、CFA+5 g/(kg ·d)石菖蒲挥发油组、CFA+10 g/(kg ·d)石菖蒲挥发油组、CFA+20 g/(kg ·d)石菖蒲挥发油组,每组各6只动物,于灌胃21 d后取材。采用免疫荧光及Western blotting技术检测各组大鼠BLA中GFAP和c-fos表达量的变化。结果 免疫荧光及Western blotting结果均显示,与control组相比,CFA组大鼠BLA中GFAP及c-fos阳性表达均显著增多(P<0.01);与CFA组相比,石菖蒲挥发油处理组GFAP和c-fos阳性表达均降低,且表达量呈剂量依赖性递减(P<0.01);其中,高剂量组GFAP和c-fos阳性表达的下降趋势较低剂量组相比更为显著(P<0.01)。结论 石菖蒲挥发油可减少CFA诱导的炎症性疼痛大鼠BLA中星形胶质细胞表达,并进一步抑制c-fos的表达。