脉冲射频对神经源性疼痛大鼠脊髓GFAP、PICK1水平的影响

目的探讨脉冲射频对神经源性疼痛(NP)大鼠脊髓胶质原纤维酸性蛋白(GFAP)、蛋白激酶C-α1相互作用蛋白(PICK1)水平的影响。方法 150只雄性成年SD大鼠随机分为假性手术组、模型组、脉冲射频2 Hz组、4 Hz组、8 Hz组,每组30只。分别于术前、术后1、3、7、14 d记录各组大鼠热缩腿反射潜伏期(TWL)、机械缩足反射阈值(MWT),抽取各组大鼠脊髓应用Western印迹法测定各组脊髓中GFAP蛋白、PICK1蛋白水平。结果模型组、2 Hz组、4 Hz组、8 Hz组术后1、3、7、14 d TWL、MWT水平显著短于假性手术组(P<0.05),模型组显著短于射频2 Hz组、4 Hz组、8 Hz组(P<0.05);随着射频频率增加,TWL、MWT水平显著升高(P<0.05),模型组、射频2 Hz组、4 Hz组、8 Hz组脊髓术后1、3、7、14 d GFAP、PICK1表达水平显著高于假性手术组(P<0.05),模型组高于射频2 Hz组、4 Hz组、8 Hz组(P<0.05);而射频组中随着作用频率的增加,脊髓GFAP蛋白、PICK1蛋白表达水平显著下降(P<0.05)。结论脉冲射频能有效减轻坐骨神经压迫性损伤所致NP大鼠热和机械性痛觉过敏,能有效抑制脊髓GFAP、PICK1表达;随着射频频率的增加,效果越理想,射频对NP有治疗效果。     

MALAT1对神经病理性疼痛大鼠STAT3信号通路的影响

目的 探讨肺腺癌转移相关转录本1(MALAT1)对神经病理性疼痛(NP)大鼠信号转导和转录激活因子3(STAT3)信号通路的影响。方法 选取置管成功的大鼠40只,随机分为对照组(注射生理盐水)、假手术组(仅暴露坐骨神经+注射生理盐水)、NP组(NP造模+注射生理盐水)、阴性慢病毒组(NP造模+注射阴性慢病毒干扰载体)和MALAT1 shRNA组(NP造模+注射MALAT1慢病毒干扰载体)。测定大鼠机械性缩足反射阈值(MWT)和热缩足反射潜伏期(TWL),采用实时荧光定量聚合酶链式反应(qRT-PCR)法检测大鼠脊髓组织中MALAT1、STAT3 mRNA表达情况,采用酶联免疫吸附试验(ELISA)法检测大鼠脊髓组织中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)表达水平,采用蛋白免疫印迹(Western Blot)法检测大鼠脊髓组织中磷酸化STAT3(p-STAT3)、STAT3蛋白表达情况。结果 与假手术组比较,造模后NP组大鼠MWT明显降低(P<0.05),TWL明显缩短(P<0.05),大鼠脊髓组织中MALAT1、STAT3...     

白藜芦醇缓解大鼠神经病理性疼痛的效果及机制

目的探讨白藜芦醇(Res)对大鼠神经病理性疼痛(NP)症状及小胶质细胞活化的影响。方法选取200~260 g的雄性SD大鼠,采用左侧L5/6脊神经结扎制备NP模型,将42只NP模型大鼠随机分为模型组和Res组各21例,Res组在术后第4天经鞘内导管注射300μg Res,10μl/次,连续7 d。同时选取22只仅暴露脊神经而不行结扎的正常大鼠作对照,模型组和对照组大鼠仅鞘内注射10μl生理盐水。分别于术前(d0)、术后第4、7、14、21天(d4、d7、d14、d21)测定各组大鼠的热痛阈潜伏期(TWL)和机械痛阈值(MWT),于d7、d14、d21取各组大鼠的L5脊髓并采用荧光免疫组化法检测小胶质细胞标记分子离子钙结合接头蛋白分子(Iba)-1和OX42的变化情况,采用酶联免疫吸附(ELISA)法检测各组脊髓的炎症因子[白细胞介素(IL)-1β、IL-6和肿瘤坏死因子(TNF)-α]水平。结果 3组大鼠d0 MWT和TML的差异无统计学意义(P>0.05),且对照组d0、d4、d7、d14、d21 MWT和TML的差异无统计学意义(P>0.05);与对照组相比,模型组及Res组d4~d21的MWT和TML水平均降低,且d7时两者水平均最低(P<0.05);模型组及Res组d7~d21的Iba-1和OX42积分光密度(IOD)均高于对照组(P<0.05),d21的脊髓IL-1β、IL-6和TNF-α水平亦高于对照组(P<0.05);除基线TWL和MWT外,Res组的以上时间点的各指标均优于模型组(P<0.05)。结论鞘内注射Res可改善NP大鼠的疼痛及炎症反应,可能与抑制小胶质细胞活化有关。     

Homer在2型糖尿病大鼠海马中的表达及意义的研究

目的评价Homer蛋白在T2DM大鼠海马中的表达及意义,并分析其与T2DM大鼠认知障碍间的关系。方法糖尿病大鼠模型组(T2DM组)、对照(Con)组大鼠各13只。取T2DM组及Con组各8只大鼠的海马组织,采用RT-qPCR法检测大鼠海马组织中Homer1c、Homer2、Homer3mRNA的表达。取两组另外各5只大鼠海马组织,Western blot法检测上述基因蛋白表达是否存在差异。结果T2DM组海马组织Homerlc[(29.99±5.11)vs(19.91±4.08)]、Homer2[(26.62±4.14)vs(15.79±2.58)]和Homer3[(35.08±3.27)vs(16.16±2.49)]的mRNA水平高于Con组(P0.05或P0.01);T2DM组海马组织Homerlc[(8.4±0.9)vs(3.2±0.5)]、Homer2[(6.8±0.6)vs(1.5±0.3)]和Homer3[(2.4±0.3)vs(0.9±0.2)]蛋白水平高于Con组(P0.05)。结论Homerlc、Homer2和Homer3可能参与T2DM认知障碍,为糖尿病脑病提供新的实验依据和潜在的治疗靶点。     

Sphk1在1型糖尿病心肌病大鼠中的自噬作用的研究

目的:观察鞘氨醇激酶1(Sphk1)在糖尿病性心肌病(DCM)大鼠中的自噬作用,为DCM的防治寻求新的靶点。方法:雄性Wistar大鼠20只被随机分为正常对照组(n=10)、DCM组(n=10)。腹腔注射链脲佐菌素(STZ)70mg/kg建立DCM大鼠模型。每2周观察大鼠体重、空腹血糖,8周后,检测两组左室舒张末期内径(LVEDd)、左室收缩末期内径(LVESd)、左室射血分数(LVEF)等;取心脏组织,行HE染色观察心脏形态。应用蛋白质印迹法检测Sphk1、自噬相关蛋白LC3II/LC3I、自噬相关蛋白Beclin 1表达水平。结果:造模8周后,与正常对照组比较,DCM组体重[(351±27)g比(198±11)g]显著降低,血糖[(6.84±0.93)mmol/L比(32.45±4.27)mmol/L]显著升高(P均=0.001);LVEDd[(7.12±0.36)mm比(6.46±0.28)mm]显著减小、LVESd[(3.39±0.14)mm比(3.72±0.25)mm]显著增加,LVEF值[(82.69±3.37)%比(62.50±3.08)%]显著降低(P<0.05或<0.01);Sphk1[(0.30±0.02)比(1.12±0.20)]、LC3II/LC3I[(0.44±0.05)比(1.03±0.14)]、Beclin 1[(0.35±0.08)比(0.73±0.12)]蛋白表达显著升高(P<0.05或<0.01)。HE染色可见心肌细胞增生肥大、排列紊乱。结论:Sphk1通过自噬促使大鼠的糖尿病性心肌病的发生发展。     

吴茱萸次碱对大鼠动脉增龄性改变的干预影响

目的观察吴茱萸次碱对大鼠动脉增龄性变化的影响,并探讨其作用机制。方法选择Wistar大鼠32只,分为3月龄组、12月龄组、18月龄组和干预组,每组8只。各组检测超氧化物歧化酶(SOD)、丙二醛以及谷胱甘肽(GSH)含量;实时PCR法检测内皮型一氧化氮合酶(eNOS)mRNA表达;Western blot法测eNOS蛋白和磷酸化蛋白表达。结果与12月龄组比较,18月龄组丙二醛水平明显升高,SOD、GSH、eNOS mRNA、磷酸化eNOS和eNOS蛋白表达明显降低(P<0.05);与18月龄组比较,干预组丙二醛[(4.96±0.22)nmol/mg vs(7.26±0.35)nmol/mg]水平明显降低,SOD[(232.07±11.16)U/mg vs(149.88±13.77)U/mg]、GSH[(12.27±1.42)μg/mg vs(5.40±0.79)μg/mg]、eNOS mRNA[(1.39±0.15)vs(0.74±0.18)]、磷酸化eNOS[(204.67±3.07)vs(121.45±2.54)]和eNOS蛋白[(591.44±2.98)vs(469.57±1.79)]表达明显升高(P<0.05);3月龄组与12月龄组上述指标比较,差异无统计学意义(P>0.05)。结论吴茱萸次碱可以提高自然增龄大鼠动脉血管的抗氧化能力,增加eNOS的表达,从而发挥延缓大鼠血管衰老的作用。     

胰岛素治疗对糖尿病大鼠肾脏自噬水平及纤维化影响的观察

目的观察胰岛素治疗对糖尿病大鼠肾脏纤维化的影响。方法将24只健康清洁级雄性SD大鼠随机分为正常对照组(NC,n=8)、糖尿病模型组(DM,n=8)和胰岛素治疗组(DMA,n=8)。HE、Masson染色,qRT-PCR和Western blot分别检测肾组织中自噬及纤维化相关指标的变化。结果HE、Masson染色结果显示,DM组肾小管上皮细胞空泡变形甚至萎缩脱落,肾小管基底膜增厚,炎症细胞浸润;肾小管及肾间质大量蓝色胶原纤维沉积。qRT-PCR结果显示,与DM组比较,DMA组肾组织中平滑肌肌动蛋白(α-SMA)[(1.06±0.42)vs(0.22±0.02)]和胶原I(Col I)mRNA[(18.03±8.42)vs(6.36±1.89)]表达下降(P0.05),自噬相关蛋白Beclin1mRNA[(0.74±0.26)vs(1.35±0.61)]表达上调(P0.05)。Western blot结果显示,与DM组比较,DMA组肾组织中α-SMA[(0.06±0.02)vs(0.02±0.01)],Col I[(0.74±0.18)vs(0.22±0.12)]以及泛素结合蛋白(p62)[(0.7±0.1)vs(0.3±0.11)]表达减少(P0.05),Beclin1[(0.02±0.01)vs(0.05±0.01)]和自噬标记蛋白(LC3)[(0.02±0.01)vs(0.06±0.04)]表达增加(P0.05)。结论自噬相关蛋白可能有参与胰岛素对糖尿病肾脏疾病治疗的作用机制。     

高压氧预处理对正常和糖尿病大鼠缺血再灌注心肌细胞凋亡的影响

目的 探讨高压氧预处理对正常和糖尿病大鼠缺血再灌注心肌细胞凋亡及Bcl-2和Bax蛋白的影响.方法 雄性Wistar大鼠75只,随机分为正常大鼠对照组,正常大鼠缺血-再灌注组,正常大鼠高压氧预处理组,糖尿病大鼠对照组,糖尿病大鼠缺血-再灌注组,糖尿病大鼠高压氧预处理组,检测各组心肌凋亡及心肌Bax、Bcl-2蛋白表达.结果 ①正常大鼠高压氧预处理组凋亡指数与正常大鼠缺血-再灌注组相比[(33.15±4.36)％vs(41.72±3.47)％],糖尿病大鼠高压氧预处理组凋亡指数与糖尿病大鼠缺血-再灌注组相比[(41.69±5.79)％vs( 52.73±6.71)％]均明显降低,有统计学差异(P＜0.05).②正常大鼠高压氧预处理组Bax蛋白灰度值与正常大鼠缺血-再灌注组相比[(170.17±7.35)vs(157.50±8.12)],糖尿病大鼠高压氧预处理组Bax蛋白灰度值与糖尿病大鼠缺血-再灌注组相比[(141.17±6.77) vs (134.0±4.73)]均明显降低,有统计学差异(P＜0.05).③正常大鼠高压氧预处理组Bcl-2蛋白灰度值与正常大鼠缺血-再灌注组相比[(158.67±7.69) vs (171.83±8.66)],糖尿病大鼠高压氧预处理组Bcl-2蛋白灰度值与正常大鼠缺血-再灌注组相比[(166.0±10.53)vs(183.33±9.15)]相比均明显增高,有统计学意义(P＜0.05).结论 高压氧预处理对正常及糖尿病大鼠均有抗心肌细胞凋亡的作用,但对正常大鼠保护作用更强,其保护机制可能与下调Bax蛋白表达,上调Bcl-2蛋白表达有关.     

烟雾暴露对大鼠肺血管细胞间黏附分子-1和基质金属蛋白酶-9表达的影响

目的 观察不同烟雾暴露量及断烟对大鼠肺血管形态、炎症和重塑的影响.方法 8周龄清洁级雄性Wistar大鼠32只,随机数字表法分为对照组、烟雾1组、烟雾2组和断烟组,每组8只.建立大鼠被动吸烟模型.分别测量各组大鼠肺血管管肇厚度占血管外径的百分率(WT%)及管壁面积占血管总面积的百分率(WA%);免疫组织化学染色检测细胞间黏附分子-1(ICAM-1)和基质金属蛋白酶9(MMP-9)在肺血管壁的表达,原位杂交法检测ICAM-1及MMP-9 mRNA在肺血管壁的表达,并分析各指标的相关性.结果 烟雾1组和烟雾2组肺血管的WT%[(15.3±2.1)%、(18.0 ±2.0)%]、WA%[(41±7)%、(50±7)%]均明显高于断烟组[(11.0±1.3)%、(35±5)%]和对照组[(10.4±2.0)%、(30±4)%],差异均有统计学意义(q值为4.93～11.16,P<0.05);烟雾1组和烟雾2组肺血管ICAM-1蛋白表达的阳性单位比值[(12.9±2.3)、(19.2±2.3)]及mRNA表达[(10.3±2.2)、(18.3±2.4)]均明显高于断烟组[(7.9±3.2)、(6.2±3.0)]和对照组[(4.7±2.3)、(2.7±1.7)],差异均有统计学意义(q值为3.28～15.76,P<0.05);烟雾1组和烟雾2组肺血管MMP-9蛋白表达的阳性单位比值[(16.1±2.8)、(22.5±3.5)]及mRNA表达[(12.5±1.8)、(20.0±3.1)]均明显高于断烟组[(12.0±2.8)、(7.0±3.4)]和对照组[(7.8±3.0)、(3.2±2.8)],差异均有统计学意义(q值为3.19～14.22,P<0.05);肺血管ICAM-1和MMP-9 mRNA表达与WT%和WA%均呈显著正相关(r值为0.619～0.703,P<0.05).结论 烟雾暴露可导致大鼠肺血管管壁增厚,上调肺血管细胞ICAM-1、MMP-9的表达,介导肺血管炎症及重塑,参与肺动脉高压的发生.戒烟后上述肺血管损害有所改善.     

燃煤污染型氟中毒大鼠肾组织中PURA基因及其蛋白的表达

目的 探讨PURA基因及其蛋白在燃煤污染型氟中毒大鼠肾组织中的表达情况.方法 SD大鼠36只,体质量80-100 g.将大鼠按体质量随机分对照组、加氟组、高氟组,每组12只,雌雄各半.对照组、加氟组和高氟组大鼠分别饲以含氟量为1.5、25.0、60.0 ms/ks的饲料.4个月后,采用RT-PCR技术及免疫组化技术检测大鼠肾组织PURA基因及其蛋白表达水平.结果 加氟组和高氟组大鼠肾组织PIJRA mRNA[(2.74±1.06)、(4.29±2.11)]及蛋白表达[(28 827.91±4801.94)、(61 146.96±4997.55)]均高于对照组[(1.13±0.87)、(7131.95±1524.54),P均<0.05)],高氟组大鼠肾组织PURA mRNA及蛋白表达高于低氟组(P均<0.05).结论 高氟可以导致大鼠肾组织PURA mRNA及蛋白表达水平增强.     

Moxibustion eases chronic inflammatory visceral pain through regulating MEK,ERK and CREB in rats

AIM To investigate the effects of herb-partitioned moxibustion(HPM) on phosphorylation of mitogen-activated extracellular signal-regulated kinase(MEK)1, extracellular signal-regulated kinase(ERK)1/2 and c AMP response element binding protein(CREB) in spinal cord of rats with chronic inflammatory visceral pain(CIVP), and to explore the central mechanism of HPM in treating CIVP.METHODS Male Sprague-Dawley rats were randomized into normal, model, HPM, sham-HPM, MEK-inhibitor and dimethyl sulfoxide(DMSO) groups. The CIVP model was established using an enema mixture of trinitrobenzene sulfonic acid and ethanol. HPM was applied at bilateral Tianshu(ST25) and Qihai(CV6) acupoints in the HPM group, while in the sham-HPM group, moxa cones and herb cakes were only placed on the same points but not ignited. The MEK-inhibitor and DMSO groups received L5-L6 intrathecal injection of U0126 and 30% DMSO, respectively. Abdominal withdrawal reflex(AWR), mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were applied for the assessment of pain behavior. The colonic tissue was observed under an optical microscope after hematoxylin-eosin staining. Expression of phosphor(p)MEK1, p ERK1/2 and p CREB in rat spinal cord was detected using Western blotting. The levels of MEK, ERK and CREB m RNA in rat spinal cord were detected using real-time polymerase chain reaction. RESULTS Compared with the normal group, the AWR scores were increased significantly(P 0.01) and the MWT and TWL scores were decreased significantly(P 0.05) in the model, sham-HPM and DMSO groups. Compared with the model group, the AWR scores were decreased significantly(P 0.01) and the MWT and TWL scores were increased significantly in the HPM and MEK-inhibitor groups(P 0.05). Compared with the sham-HPM and DMSO groups, the AWR scores were decreased significantly(P 0.01) and the MWT and TWL scores were increased significantly(P 0.05) in the HPM and MEK-inhibitor groups. Compared with the normal group, the expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were increased significantly in the model, sham-HPM and DMSO groups(P 0.01 or 0.05). Compared with the model group, the expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were reduced significantly in the HPM and MEK-inhibitor groups(P 0.01 or 0.05). Compared with the sham-HPM and DMSO groups, expression of p MEK1, p ERK1/2 and p CREB proteins and the levels of MEK, ERK and CREB m RNA in rat spinal cord were reduced significantly in the HPM and MEK-inhibitor groups(P 0.01 or 0.05). CONCLUSION HPM down-regulates protein phosphorylation of MEK1, ERK1/2 and CREB, and m RNA expression of MEK, ERK and CREB, inhibiting activation of the MEK/ERK/CREB signaling pathway in the spinal cord of CIVP rats, which is possibly a critical central mechanism of the analgesic effect of HPM.     

坐位低频全身振动训练对老年下肢残疾者肌肉力量及行走能力的影响

目的探讨坐位低频全身振动训练(WBVT)对老年下肢残疾者肌肉力量及行走能力的影响。方法募集上海市杨浦区殷行街道自愿报名的老年下肢残疾者20例(因外伤致残,残疾等级为42~44),其中男性9例,女性11例,年龄(66.6±4.8)岁,所有受试者接受每周3 d共计8周的WBVT,比较训练前后受试者膝关节屈、伸肌肌力、6分钟步行测试(6 MWT)、10米行走测试(10 MWT)和计时起立-行走(TUG)测试结果。应用SPSS 22.0统计软件对数据进行分析,训练前后比较采用配对t检验。结果所有受试者皆顺利完成振动训练及测量,无缺失及不适、不安全情况发生。受试者WBVT训练后相比训练前膝关节屈肌肌力[(39.36±16.09)vs(37.37±16.12)Nm]、伸肌肌力[(58.18±21.31)vs(56.49±21.69)Nm]增高,TUG[(7.73±2.17)vs(9.70±2.22)s]和10 MWT[(7.51±2.26)vs(7.86±2.30)s]水平降低,6 MWT[(438.74±125.10)vs(401.99±114.08)m]水平升高,差异具有统计学意义(P0.05)。结论 8周坐位低频WBVT可明显提高老年下肢残疾者膝关节屈、伸肌肌力,显著改善行走平衡能力和提高速度。     

阿托伐他汀在1-磷酸鞘氨醇诱导心肌细胞肥大中的作用

目的研究阿托伐他汀对1-磷酸鞘氨醇(S1P)诱导乳鼠心肌细胞肥大反应中的作用。方法原代培养乳鼠心肌细胞,测定心肌细胞体积和[3H]-亮氨酸掺入量作为心肌细胞肥大的指标。乳鼠心肌细胞使用不同浓度的阿托伐他汀(atorvastatin),加入S1P,[3H]-亮氨酸掺入量作为心肌细胞蛋白摄取量;分别用qPCR和Western blot法检测心肌细胞的β-肌球蛋白(β-MHC)的mRNA和蛋白质表达水平;用qPCR检测心肌细胞的心房利钠肽(ANF)的mRNA表达水平。结果与S1P组比较,阿托伐他汀10μmol/L处理组[3H]-亮氨酸掺入率减少[(234.89%±31.23%)比(342.23%±31.60%),P=0.205],β-MHC的mRNA和蛋白表达水平下降[(0.59±0.14)比(0.84±0.20),P=0.318]和[(0.55±0.09)比(0.98±0.15),P=0.223],ANF的mRNA表达水平降低[(0.51±0.13)比(0.76±0.19),P=0.445];与S1P组比较,阿托伐他汀20μmol/L处理组[3H]-亮氨酸掺入率明显减少[(189.07%±17.69%)比(342.23%±31.60%),P<0.01],β-MHC的mRNA和蛋白表达水平显著下降[(0.50±0.12)比(0.84±0.20),P<0.01]和[(0.35±0.08)比(0.98±0.15),P<0.01],ANF的mRNA水平明显降低[(0.47±0.12)比(0.76±0.19),P<0.01]。结论阿托伐他汀可抑制S1P诱导的心肌细胞肥大,并可减少S1P诱导的β-MHC和ANF表达。     

Transcutaneous electrical nerve stimulator of 5000 Hz frequency provides better analgesia than that of 100 Hz frequency in mice muscle pain model

Transcutaneous electrical nerve stimulators (TENSs) have been proved to be effective in muscle pain management for several decades. However, there is no consensus for the optimal TENS program. Previous research demonstrated that a 100 Hz TENS (L-TENS) provided better analgesia than a conventional TENS (< 5 Hz). However, no research compared a higher-frequency (> 100 Hz) TENS with a 100 Hz TENS. We used a 5000 Hz (5 kHz) frequency TENS (M-TENS) and an L-TENS to compare analgesic effect on a mice skin/muscle incision retraction model. Three groups of mice were used (sham, L-TENS, and M-TENS) and applied with different TENS programs on Day 4 after the mice skin/muscle incision retraction model; TENS therapy was continued as 20 min/d for 3 days. Mice analgesic effects were measured via Von Frey microfilaments with the up–down method. After therapy, mice spinal cord dorsal horn and dorsal root ganglion (DRG) were harvested for cytokine evaluation (tumor necrosis factor-α and interleukin-1β) with the Western blotting method. Our data demonstrated that the M-TENS produced better analgesia than the L-TENS. Cytokine in the spinal cord or DRG all expressed lower than that of the sham group. However, there is no difference in both cytokine levels between TENSs of different frequencies in the spinal cord and DRG. We concluded that the M-TENS produced faster and better mechanical analgesia than the L-TENS in the mice skin/muscle incision retraction model. Those behavior differences were not in accordance with cytokine changes in the spinal cord or DRG.     

Effects of DA-9701, a Novel Prokinetic Agent,on Phosphorylated Extracellular Signal-Regulated Kinase Expression in the Dorsal Root Ganglion and Spinal Cord Induced by Colorectal Distension in Rats

Background/Aims

DA-9701, a standardized extract of Pharbitis Semen and Corydalis Tuber, is a new prokinetic agent that exhibits an analgesic effect on the abdomen. We investigated whether DA-9701 affects visceral pain induced by colorectal distension (CRD) in rats.

Methods

A total of 21 rats were divided into three groups: group A (no CRD+no drug), group B (CRD+no drug), and group C (CRD+DA-9701). Expression of pain-related factors, substance P (SP), c-fos, and phosphorylated extracellular signal-regulated kinase (p-ERK) in the dorsal root ganglion (DRG) and spinal cord was determined by immunohistochemical staining and Western blotting.

Results

The proportions of neurons in the DRG and spinal cord expressing SP, c-fos, and p-ERK were higher in group B than in group A. In the group C, the proportion of neurons in the DRG and spinal cord expressing p-ERK was lower than that in group B. Western blot results for p-ERK in the spinal cord indicated a higher level of expression in group B than in group A and a lower level of expression in group C than in group B.

Conclusions

DA-9701 may decrease visceral pain via the downregulation of p-ERK in the DRG and spinal cord.     

Immunoreactive dynorphin in mammalian spinal cord and dorsal root ganglia.

The distribution of immunoreactive dynorphin (ir-dynorphin) has been determined in dorsal and ventral aspects of spinal cord and in dorsal root ganglia of rabbit and rat. Concentrations are highest in dorsal root, with intermediate levels in ventral cord and low levels in dorsal root ganglia of both species. Levels of ir-dynorphin are relatively uniform over examined segments (vertebrae C2-S3) of rabbit spinal cord and dorsal root ganglia. Gel permeation chromatography of extracts from rabbit dorsal and ventral spinal cord and dorsal root ganglia revealed at least three immunoreactive components of differing molecular size in all three structures. Multiple unilateral or bilateral dorsal rhizotomy (vertebrae C5-T1) in rat did not affect levels of ir-dynorphin in spinal cord. As reported [Goldstein, A. & Ghazarossian, V. E. (1980) Proc. Natl. Acad. Sci. USA 77, 6207-6210], midthoracic spinal transection was without effect. Within the spinal cord, the neuropeptide appears, most probably, to be contained in short-axoned neurons. We surmise that this potent opioid peptide may participate in the processing of sensory information in spinal cord.     

Neuroprotective effect of tanshinone IIA against neuropathic pain in diabetic rats through the Nrf2/ARE and NF-κB signaling pathways

The study aims to investigate whether tanshinone (TSN) IIA affects diabetic neuropathic pain (DNP) via the Nrf2/AR and NF-κB signaling pathways. Rats were randomly assigned into DNP group, TSN group (injected with TSN IIA), TSN + DRB group (injected with TSN IIA and 15 mg/kg Nrf2/ARE inhibitors), TSN + PDTC group (injected with TSN IIA and 60 mg/kg NF-κB inhibitors) or control group. The first four groups were successfully established as DNP models after injection of streptozotocin. The blood glucose level, mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), nerve conduction velocity (NCV) and antioxidase level were detected. Transmission electron microscopy and toluidine blue staining were utilized to observe the sciatic nerve. RT-qPCR and western blot were used to measure expression levels of Nrf2/ARE and NF-κB signaling pathway-related genes. Blood glucose, malondialdehyde (MDA) and erythrocyte glutathione peroxidase (GSH-Px) levels as well as expression of Keap1 and NF-κB were increased in the TSN, TSN + DRB and TSN + PDTC groups compared to control group. Furthermore, the MWT, TWL, NVC, and superoxide dismutase (SOD) levels and expression of Nrf2, heme oxygenase 1 (HO-1) and inhibitory kappa B (IκB) decreased in the treatment groups. The TSN + DRB and TSN + PDTC groups showed similar trend when compared with the TSN group, while the opposite trend was observed in the TSN group when compared with the DNP group. Our study demonstrates that TSN IIA alleviates neuropathic pain by activating the Nrf2/ARE signaling pathway and inhibiting the NF-κB signaling pathway in diabetic rats.     

Developing dorsal root ganglion neurons require trophic support from their central processes: evidence for a role of retrogradely transported nerve growth factor from the central nervous system to the periphery.

Injury to the peripheral processes produces a profound cell loss (40-50%) in the dorsal root ganglion of newborn rats. Although division of central processes produces little or no cellular change in sensory ganglion of adult animals, no information has been available on the effect of dorsal root section in developing dorsal root ganglion. We show that 6 days after dorsal rhizotomy on newborn rats, there is a 50% decrease in neuronal number in L5 dorsal root ganglion. A combined central and peripheral lesion of the sensory process results in a greater decrease in neuronal number (70%). Both of these effects can be prevented by the concomitant treatment with nerve growth factor. We also demonstrate that 125I-Ia-labeled nerve growth factor is retrogradely transported with high selectivity from the spinal cord to the dorsal root ganglion via the dorsal roots. The results indicate that trophic support for developing sensory neurons is provided through the central processes. This is presumably due to the uptake and retrograde transport of a trophic factor by the terminals of the central processes. The data suggest that nerve growth factor may be the trophic factor.     

昆布多糖对大鼠心肌缺血/再灌注模型葡萄糖调节蛋白-78及半胱氨酸天冬氨酸蛋白水解酶12蛋白表达含量的影响

目的研究昆布多糖(Lam)对大鼠心肌缺血/再灌注(MI/RI)模型中葡萄糖调节蛋白-78(GRP-78)及半胱氨酸天冬氨酸蛋白水解酶12(Caspase 12)蛋白表达含量的影响,探讨其对大鼠心肌是否有保护作用。方法选取32只雄性SD大鼠,随机分为4组:假手术组(sham组)、MI/RI组、Lam低剂量组、Lam高剂量组。采用左冠状动脉结扎法制作大鼠MI/RI模型。酶联免疫吸附试验(ELISA)测定肌酸激酶同工酶MB(CK-MB),比色法测定髓过氧化物酶(MPO)的表达量。应用蛋白质免疫印迹(Western blotting)检测各组中大鼠心肌GRP-78、Caspase 12、B淋巴细胞瘤-2蛋白(Bcl-2)蛋白的表达情况。光镜下观察心肌组织的病理形态学改变。伊文思蓝(Evans)、氯化三苯基四氮唑红(TTC)双染色法测定心肌梗死面积。采用SPSS 21.0软件进行统计分析。结果与MI/RI组相比,低、高剂量组的CK-MB[(93.74±5.37)和(72.71±5.63)和(59.79±9.67)U/L]、MPO[(72.66±3.40)和(58.92±4.88)和(46.06±5.74)U/L]、GRP-78[(1.13±0.02)和(0.81±0.01)和(0.66±0.01)]、Caspase 12[(1.45±0.10)和(0.82±0.06)和(0.62±0.02)]表达显著减少(P0.01),Bcl-2[(1.01±0.04)和(1.19±1.10)和(1.41±0.02)]表达显著升高(P0.01)。与MI/RI组相比,Lam各处理组的心肌组织损伤有不同程度的减轻。与MI/RI组比较,Lam各处理组心肌梗死面积显著减少[(55.36±2.47)%和(46.63±2.10)%和(38.40±2.07)%,P0.05]。结论 Lam能减轻大鼠MI/RI,对MI/RI的心肌有保护作用。其机制可能是Lam抑制GRP-78的过度表达,减轻了由内质网应激介导细胞凋亡途径的激活,下调Caspase 12凋亡通路,增强Bcl-2的表达,从而抑制心肌细胞凋亡。     

Similarities in development of substance P and somatostatin in peripheral sensory neurons: effects of capsaicin and nerve growth factor.

Development of the two putative peptide neurotransmitters, substance P (SP) and somatostatin (SS), were compared in rat dorsal root ganglion (DRG) and spinal cord in vivo. The content of SS in the sixth cervical DRG increased 5-fold during the first 5 weeks of life, rising from 24 pg per ganglion at birth. SP content increased 4.5-fold during the first 5 weeks, from 56 pg per ganglion at birth. The developmental profiles for these two peptides were virtually parallel, suggesting that their respective neuronal populations developed in synchrony. Treatment with nerve growth factor (NGF) significantly increased the content of both SP and SS in the DRG and dorsal spinal cord. Conversely, treatment with capsaicin significantly decreased both SP and SS in the DRG and dorsal spinal cord. Consequently, experiments involving NGF or capsaicin treatment of sensory neurons must be interpreted with extreme care, because specificity is not limited to a single peptide phenotype. Although the mechanisms of action of NGF and capsaicin on SP and SS have not been defined, the similarity of the responses of the two peptides suggests that their development may be regulated by similar processes.