电压门控钠离子通道与内脏高敏感性

电压门控钠离子通道是一种多亚基跨膜糖蛋白,在神经元动作电位的产生和传播过程中起着关键作用,因此它与内脏高敏感性关系密切。阐明电压门控钠离子通道与内脏高敏感性的关系有助于探索某些胃肠道功能性疾病治疗的新方法。     

徐长卿对三硝基苯磺酸诱导的大鼠结肠炎的作用

目的:探讨徐长卿对2,4,6-三硝基苯磺酸(trinitrobenzenesulfonic acid,TNBS)诱导的大鼠结肠炎的作用.方法:将40只♂SD大鼠随机分为4组:正常组、模型组、徐长卿组和巴柳氮组.除正常组外,其余3组大鼠均以TNBS灌肠造模.灌肠24h后,徐长卿组开始每天给予徐长卿4g/kg;巴柳氮组给予巴柳氮钠1g/kg灌胃治疗10d.每天观察大鼠一般情况,给药结束后,观察大鼠结肠大体损伤及病理,酵素免疫分析法(enzyme-linked immunosorbant assay,ELISA)检测肠组织肿瘤坏死因子(tumor necrosis factor,TNF)-α、白介素(interleukin,IL)-1β及IL-10水平.结果:两治疗组体质量较模型组增加,但差异无统计学意义;两治疗组疾病活动指数(disease activity index,DAI)评分较模型组明显下降(0.70±1.06,0.67±0.71vs2.38±1.51,P<0.05).徐长卿组、巴柳氮组结肠大体损伤及病理评分较模型组显著下降(1.05±0.83,1.06±0.85vs2.94±0.94;1.65±1.67,2.00±1.80vs6.00±1.67,均P<0.01).徐长卿组较模型组TNF-α、IL-1β水平明显降低(P<0.01),IL-10水平无统计学差异.巴柳氮组较模型组TNF-α、IL-1β、IL-10水平均明显降低(P<0.01).结论:徐长卿能有效改善TNBS诱导的大鼠结肠炎,其机制可能与调节细胞因子水平有关.     

肝素治疗在三硝基苯磺酸诱导的结肠炎模型中的作用

目的 探讨三硝基苯磺酸(TNBS)诱导的大鼠实验性结肠炎模型中凝血异常与炎症的关系.方法 将40只SD大鼠分为4组:正常对照组、结肠炎组、肝素治疗组和柳氮磺吡啶(SASP)治疗组.检测各组的PT、APTT、抗凝血酶(AT)活性,及组织大体评分和病理评分、血中TNFα水平,并对结果进行统计学分析.结果 TNBS诱导的结肠炎模型中PT及APTT均比正常对照组缩短[(14.83±0.45)s比(16.68±1.08)s及(12.49±1.30)s比(29.06±1.60)8,P值均<0.05],AT活性较正常对照组下降[(111.33±8.50)%比(122.13±3.52)%,P<0.05].肝素治疗组的PT及APTT.均较结肠炎组延长[(17.83±0.78)s比(14.83±0.45)s及(53.34.±9.49)8比(12.49±1.30)s,P值均<0.05],AT活性较结肠炎组为高[(131.67±6.92)%比(111.33±8.50)%,P<0.05].SASP治疗组与结肠炎组比较,PT和APTT差别无统计学意义(P>0.05),AT活性较结肠炎组高[(122.33±5.82)%比(111.33±8.50)%,P<0.05].肝素治疗组大体评分低于结肠炎组(2.50±0.55比4.75±1.16,P<0.05),组织病理评分明显低于结肠炎组(3.83±0.41比7.75±1.04,P<0.05),TNFα水平比结肠炎组减低[(84.75±18.03)ag/L比(149.93±23.52)ng/L,P<0.05].结论 TNBS诱导的实验性结肠炎模型中存在凝血异常;肝素治疗TNBS诱导的实验性结肠炎模型有效.这提示凝血系统异常在实验性结肠炎发生发展中可能起到一定作用.     

三硝基苯磺酸(TNBS)诱导大鼠胰腺纤维化的病理学演变

目的观察三硝基苯磺酸(TNBS)胰管内注射诱导大鼠慢性胰腺炎胰腺纤维化过程中的病理演变规律,进一步从病理学角度揭示其发生机制.方法通过胰管内注射含2% TNBS的乙醇磷酸盐缓冲液诱导大鼠慢性胰腺炎模型,对照组仅注射等体积乙醇磷酸盐缓冲液,并于术后72 h、3周、4周、5周、6周、7周处死大鼠.应用光镜、电镜观察不同时间点胰腺组织的病理学变化.结果 2%TNBS胰管注射后早期主要以胰腺组织炎症、水肿,腺泡细胞坏死等改变为主;3周后则以纤维化为主,主要表现为胰腺星状细胞活化和成纤维细胞增生,腺泡萎缩及间质内大量纤维沉积.结论胰管内注射TNBS引起的慢性胰腺炎的病理改变是基于胰腺实质急性损伤而发生的胰腺组织再生与修复,最终形成胰腺纤维化.     

电压门控钠通道亚单位在大鼠肠易激综合征模型中变化的研究

背景：电压门控钠通道（VGSC）在神经元动作电位的产生和传递中起着极为重要的作用。近年来它与内脏高敏感性的关系越来越受到重视。目的：探讨VGSC亚单位的变化与大鼠肠易激综合征（IBS）内脏高敏感性之间的关系。方法：以新生大鼠直肠内气囊扩张制作IBS的动物模型，在其成年后取L6-S2脊髓背根神经节，采用逆转录聚合酶链反应（RT-PCR）半定量法对背根神经节细胞表面VGSC Nav1．1、Nav1．6、Nav1．7、Nav1．8和Nav1．9五种α亚单位mRNA的含量进行检测．并以原位杂交的方法对Nav1．8的表达进一步加以确认；采用酶联免疫吸附试验（ELISA）法对大鼠肠道组织神经生长因子（NGF）的含量进行检测。结果：背根神经节细胞表面仅亚单位Nav1．8mRNA的表达增加，而Nav1．1、Nav1．6、Nav1．7和Nav1．9的表达没有改变，原位杂交定性分析也证实造模组Nav1．8含量增加；造模组肠道组织NGF的含量显著高于对照组。结论：新生大鼠直肠内气囊扩张使其脊髓背根神经节细胞Nay1．8mRNA的表达增加，而其他几种常见仅亚单位的含量均未发生改变。这种变化可能与肠道组织NGF表达的增加有关。     

三硝基苯磺酸诱导小鼠溃疡性结肠炎模型制备的技术改良

目的:改良2,4,6-三硝基苯磺酸(TNBS)硅胶管灌肠诱导制备小鼠溃疡性结肠炎(UC)模型的方法,提高造模的成功率和模型的稳定性,并探索造模的适宜剂量和时间.方法:选用40只SPF级♂Balb/c小鼠,6-8周龄,随机分为正常对照组、不同浓度TNBS组(37.5mg/kg、75mg/kg、150mg/kg、200mg/k g),每组8只,使用灌胃针替代硅胶管灌肠,并于灌肠后2d和4d分别处死4只小鼠,观察不同组别小鼠生理状态、结肠组织的损伤及病理学的改变情况.结果:在灌胃针造模过程中未发生小鼠死亡现象;对照组小鼠一般情况及结肠黏膜组织无异常改变;小鼠灌肠后出现少食、少动、体质量下降、皮毛光泽度下降、腹泻、便血.不同浓度TNBS造模组随着TNBS剂量的增加,小鼠结肠黏膜组织出现充血、出血、水肿、炎症、溃疡的程度增加.HE染色可见结肠组织水肿、炎症细胞浸润、杯状细胞缺失、溃疡形成的程度逐渐增加.其中TNBS37.5mg/kg、75mg/kg组于造模后2d,以上损伤现象开始缓解,未形成稳定的UC模型;150mg/kg、200mg/kg组持续时间较长,以上损伤现象4d内未见明显缓解,150mg/kg组表现为较典型的UC模型,200mg/kg为重症UC模型.结论:对制造小鼠UC模型进行相关技术改进,使灌肠更加简便,提高造模效率,显著增加了模型的稳定性.     

肠吉泰对内脏高敏大鼠电压门控钠通道Nav1.8和神经生长因子的影响

[目的]观察肠吉泰对内脏高敏大鼠电压门控钠通道(VGSC)Nav1.8和神经生长因子(NGF)的影响。[方法]40只新生SD大鼠随机分成正常组、模型组、肠吉泰A组和B组4组;用醋酸刺激法建立内脏高敏大鼠模型;肠吉泰A组和B组分别每日予肠吉泰30g/kg和50g/kg灌胃,正常组和模型组予等量去离子水灌胃;4周后,采用直肠气囊扩张法评估内脏敏感性;取L6～S2脊髓背根神经节和直肠组织,采用RT-PCR和ELISA法分别检测Nav1.8 mRNA和NGF含量。[结果]与正常组相比,模型组大鼠内脏敏感性增高(P0.01),Nav1.8 mRNA和NGF含量均明显增高(P0.05);肠吉泰B组与正常组相比,内脏敏感性、Nav1.8 mRNA和NGF均差异无统计学意义;与模型组比,P0.01或P0.05。[结论]高剂量肠吉泰可能通过降低肠道NGF和脊髓背根神经节Nav1.8来降低内脏敏感性。     

雷公藤红素对三硝基苯磺酸诱导的大鼠结肠炎的保护作用

背景：传统药物对炎症性肠病疗效不甚理想，寻找新型而有效的药物一直是该领域的研究热点。目的：观察雷公藤红素对三硝基苯磺酸（TNBS）诱导的大鼠结肠炎的保护作用，并初步探讨其可能机制。方法：以TNBS诱导大鼠结肠炎模型。将动物随机分为正常对照组、模型组、助溶剂对照组以及雷公藤红素低剂量组（每天0．5mg／kg）和高剂量组（每天1mg／kg）。以大体和组织学评分评价结肠炎症程度。以免疫组化方法检测结肠组织核因子（NF）-kBp65的表达，以半定量逆转录聚合酶链反应（RT-PCR）检测白细胞介素（IL）-1β和肿瘤坏死因子（TNF）-α mRNA的表达。结果：高、低剂量雷公藤红素均能显著改善结肠组织大体和组织学评分，降低NF-kB p65以及IL-1β、TNF-α mRNA的表达。结论：雷公藤红素对TNBS诱导的大鼠结肠炎具有显著保护作用，抑制促炎细胞因子的产生可能是其主要作用机制之一。     

三硝基苯三磷酸腺苷鞘内注射对大鼠内脏高敏感性的影响

背景：P2X受体在感觉神经元中表达丰富，近年研究表明其在伤害性信息的传导过程中起有重要作用。目的：研究选择性P2X受体拮抗剂三硝基苯三磷酸腺苷（TNP-ATP）鞘内注射对大鼠内脏高敏感性的影响，了解P2X受体与内脏高敏感性的关系。方法：30只健康Wistar大鼠随机分为5组，每组6只。以慢性避水应激建立内脏高敏感模型（S组），以假应激作为对照（C组），分别予鞘内注射0．9％NaCl溶液10μl（SNaCl组和CNaCl组）、TNP-ATP50μg／10μl（ST50组和CT50组）和TNP-ATP25μg／10μl（ST25组）。以结直肠扩张（CRD）时的腹壁肌电图内脏运动反射（VMR）幅度值和脊髓灰质c-fos蛋白的表达为指标观察内脏敏感性的变化。结果：鞘内注射后，SNaCl组CRD时的VMR幅度值（40mmHg：P〈0.05；60和80mmHg：P〈0.01）和脊髓灰质c-fos免疫阳性细胞数（1区：P〈0.01；3区：P〈0.05）较CNaCl组显著增加；ST50组VMR幅度值（40和80mmHg：P〈0.05,60mmHg：P〈0.01）和c-los免疫阳性细胞数（1区和3区：P〈0.05）较SNaCl组显著降低；ST25组VMR幅度值和c-fos免疫阳性细胞数无明显变化。结论：TNP-ATP50μg/10μl鞘内注射可降低大鼠的内脏高敏感性，提示在心理应激所致的内脏高敏感过程中有P2X受体参与。     

清肠栓调节三硝基苯磺酸诱导结肠炎大鼠结肠黏膜细胞增殖的影响

[目的]从细胞增殖动力学角度探讨清肠栓促进结肠溃疡愈合的作用机制.[方法]制备三硝基苯磺酸(TNBS)诱导结肠炎大鼠.造模3 d,分为清肠栓高剂量组、清肠栓低剂量组、柳氮磺胺吡啶(SASP)组、模型对照组、模型组和正常组.给药7 d后,取大鼠结肠病变部位标本,进行组织学评价,运用AB-PAS染色观察杯状细胞数量及其分泌黏液功能,免疫组化染色法检测增殖细胞核抗原(PCNA)表达.[结果]与清肠栓低剂量组、SASP组、模型对照组和正常组比较,清肠栓高剂量组大鼠结肠黏膜炎症消除和溃疡愈合,杯状细胞数量及黏液增加,溃疡边缘腺体细胞增殖加强,PCNA表达增加(P＜0.05).[结论]清肠栓具有促进结肠炎大鼠结肠黏膜细胞增殖、增加杯状细胞的数量和分泌黏液的水平等作用,能够促进结肠溃疡愈合过程.     

拮抗或激活促肾上腺皮质激素释放因子受体对肠易激综合征大鼠内脏敏感性及结肠动力的影响

目的 探讨促肾上腺皮质激素释放因子(CRF)及其受体对肠易激综合征大鼠内脏敏感性及结肠动力的影响.方法 SD大鼠60只,随机平均分入空白组(不做处理)、模型组(特殊气味条件刺激和肢体束缚直肠刺激非条件刺激轮替致敏)、干预对照组(造模前侧脑室注射0.9%NaC1)、干预一组(造模前侧脑室注射CRF-R1拮抗剂)和干预二组(造模前侧腑室注射CRF-R2激动剂).采用腹部收缩反射(AWR)评分标准评估各组大鼠肠道敏感性,记录各组大鼠结肠快、慢波波动率、最大振幅、收缩波数及振幅指数等电生理活动改变.采用SPSS16.0统计软件分析,计量资料采用方差分析,等级资料采用秩和检验.结果 以AWR=3分时所需的直肠注水量作为评价指标,模型组大鼠[(0.90±0.11)ml]较空白组[(1.23±0.07)ml]内脏敏感性增高(F＝82.586,P＜0.01);结肠电生理活动增强,造模成功.干预对照组直肠注水量为(0.81±0.11)ml,与模型组[(0.90±0.11)ml]差异无统计学意义(F＝3.734,P＞0.05),干预一组[(1.28±0.07)ml,F＝161.878,P＜0.01]和干预二组[(1.22±0.05)ml,F＝121.564,P＜0.01]较干预对照组内脏敏感性降低.干预对照组大鼠结肠快、慢波波动率、最大振幅、收缩波数及振幅指数等电生理活动与模型组无明显差异(P均＞0.05);干预一组和干预二组大鼠结肠电生理活动均较干预对照组明显减弱(均P＜0.05).结论 CRF在IBS发病中起重要作用,抑制CRF-R1或激活CRF-R2可降低1BS大鼠内脏敏感性并抑制结肠运动.

Abstract：

Objective To explore the effect of corticotropin releasing factor (CRF) and its receptor on visceral sensitivity and colon motility of irritable bowel syndrome (IBS) rats. Methods sixty SD rats were divided randomly and equally into control group (without treatment),model group (sensitized in turn with camphor odor as conditional stimulation and physical restraint in combination with rectal distention pressure as non-conditional stimulation),treatment control group (injected physiological saline into lateral ventricles before treatment),treatment group 1 (injected CRF-R1antagonist into lateral ventricles before treatment),treatment group 2 (injected CRF-R2 agonist into lateral ventricles before treatment). Then the rats' visceral sensitivity were assessed by AWR,and colonic electricity activities such as volatility,maximum amplitude of fast wave and slow wave,interdigestive number of contraction wave and index of contraction were recorded. The data was analyzed with SPSS 16. 0 software. Results By the amount of ractal water injection to reach AWR=3 as the evaluation index,model group [(0. 90±0. 11) ml] showed higher visceral sensitivity than that of control group [(1. 23±0. 07) ml,F=82. 586,P＜0. 01],and colonic electricity activity increased (P＜0. 05),model was successfully set up. There was no significant difference of the amount of ractal water injection between model group [(0. 90±0. 11) ml] and treatment control group [(0. 81±0. 11) ml,F=3. 734,P＞0. 05]. Compared with treatment control group,the visceral sensitivity decreased in treatment group 1 [(1. 28±0. 07) ml,F=161. 878,P＜0. 01] and treatment group 2 [(1. 22±0.05) ml,F=121. 564,P＜0. 01]. There was no significant difference between treatment control group and model group in electricity activities such as volatility,maximum amplitude of fast wave and slow wave,interdigestive number of contraction wave and index of contraction (all P＞0. 05). While the electricity activities was weakened in treatment group 1 and 2 compared with the treatment control group (all P＜0. 05). Conclusions CRF plays an important role in the pathogenesis of IBS. Inhibition of CRF-R1 or activation of CRF-R2 may lower visceral hypersensitivity and decrease colon motility of rats.     

牛磺酸对三硝基苯磺酸诱导的结肠炎大鼠肠纤维化的抑制作用

目的 探讨牛磺酸对三硝基苯磺酸(TNBS)诱导的结肠炎大鼠肠纤维化的影响.方法 32只SD大鼠均分为对照组、模型组、低剂量和高剂量牛磺酸组.对照组以0.9%氯化钠溶液灌肠,其余3组以TNBS灌肠诱导建立结肠炎模型.低剂量和高剂量牛磺酸组于造模前1周每日分别给予牛磺酸400和800 mg/kg干预,直至造模结束.观察大鼠临床表现及疾病活动指数(DAI),行结肠大体评分和组织学评分,检测大鼠结肠长度、结肠重量.测定结肠组织中羟脯氨酸(Hyp)、Ⅰ型胶原蛋白、转化生长因子-β1(TGF-β1)蛋白和mRNA、Smad3蛋白和mRNA水平.结果 与对照组相比,模型组大鼠体重减轻、DAI评分升高、结肠狭窄伴近端扩张、结肠长度缩短、结肠重量增加、大体评分也显著升高(P<0.01).牛磺酸干预后,大鼠体重、DAI评分、结肠长度等指标均有所改善.模型组纤维化评分为1.88±0.35.较对照组明显增加(0.25±0.46,P<0.01);低剂量和高剂量牛磺酸组纤维化评分分别为1.25±0.71和0.75±0.47,较模型组下降(P<0.05).模型组大鼠结肠Hyp、TGF-β1、Ⅰ型胶原蛋白、Smad3蛋白和mRNA含量均较低剂量和高剂量牛磺酸组明显上升(P值均<0.05).结论 牛磺酸能有效抑制TNBS诱导的结肠炎大鼠肠纤维化,其抗纤维化机制可能与下调TGF-β1、抑制TGF-β/Smad3通路有关,为解决克罗恩病肠纤维化和肠狭窄提供一定的实验依据.     

Effects and mechanism of the selective COX‐2 inhibitor,celecoxib, on rat colitis induced by trinitrobenzene sulfonic acid

OBJECTIVE: To investigate the action of celecoxib (a selective COX‐2 inhibitor) in a rat model of colitis induced by trinitrobenzene sulfonic acid (TNBS). METHODS: Rats were randomized into four groups. Colitis was induced in groups 1 and 2 by intracolonic administration of TNBS (25 mg/mL) in 50% ethanol (0.25 mL). The rats in group 1 received oral celecoxib (1.25 mg/kg) and those in group 2 received distilled water (1 mL/0.3 kg), beginning 3 h before induction of colitis and continuing twice daily thereafter for up to 7 days. The rats in group 4 received oral celecoxib (1.25 mg/kg) twice daily for 7 days and those in group 3 were healthy controls. All rats that survived 7 days were killed and both the severity of colonic mucosal damage and the prostaglandin E₂ (PGE₂) concentrations of the colonic mucosa were assessed. RESULTS: The colonic mucosal damage scores for groups 1 and 2 were 11.15 ± 3.30 and 8.50 ± 2.82, respectively, both of which were significantly higher than the score for the healthy controls (0.62 ± 0.09; P < 0.01, P < 0.01). The score of group 1 was significantly higher than that of group 2 (P < 0.05). No difference was found between the scores of groups 3 and 4. The mucosal concentrations of PGE₂ in groups 1 and 2 were 12.00 ± 4.33 pg/µg and 17.20 ± 9.62 pg/µg, respectively, both of which were significantly higher than the concentration in the healthy controls (6.02 ± 3.39 pg/µg; P < 0.05, both). The PGE₂ concentration of group 1 was decreased significantly compared with that of group 2 (P < 0.05). No difference was found between groups 3 and 4. CONCLUSION: The results suggest that treatment with celecoxib exacerbates inflammation‐associated colonic injury in experimental colitis induced by TNBS. This preliminary study shows that the mechanism is related to suppression by the COX‐2 inhibitor of the PG derived from COX‐2, but further study is needed to identify if there are other related mechanisms.     

霉酚酸对内皮素-1诱导的肺动脉平滑肌细胞增殖迁移收缩的影响

目的 研究霉酚酸对内皮素-1诱导的大鼠肺动脉平滑肌细胞(PASMCs)的增殖、收缩和迁移的影响,探讨霉酚酸酯对肺动脉高压的作用机制.方法 采用四甲基偶氮唑蓝(MTT)、划痕实验、Millicell培养小室及测微尺计量的方法观察霉酚酸对内皮素-1诱导PASMCs增殖、迁移和收缩的影响,并了解鸟嘌呤对霉酚酸抑制PASMCs增殖的逆转作用.采用配对t检验进行统计分析.结果 与内皮素-1组相比,低浓度霉酚酸组平滑肌细胞增殖降低[吸光度(A)值:0.348±0.036与0.447±0.013,t=6.357,P=0.000];高浓度MPA组进一步降低.与低浓度霉酚酸组相比,霉酚酸加鸟嘌呤组平滑肌细胞增殖有所增加(A值:0.390±0.018与0.348±0.036,t=2.573,P=0.028).霉酚酸组细胞平均迁移距离较内皮素-1组缩短,霉酚酸组平均迁移细胞数较内皮素-1组减少,霉酚酸组平均细胞长度长于内皮素-1组.结论 霉酚酸具有抑制内皮素-1诱导的PASMCs增殖、迁移和收缩的作用,外源性鸟嘌呤可部分逆转霉酚酸抑制PASMCs增殖的作用.     

The effects of toxic concentrations of theophylline on oxygen consumption, ventricular work, acid base balance, and plasma catecholamine levels in the dog

Theophylline poisoning, characterized in part by tachyarrhythmias, hypokalemia, and a metabolic acidosis, is similar to that expected from excessive beta-adrenergic activity. Using a previously described canine model of theophylline poisoning, invasive cardiovascular parameters were determined along with oxygen consumption (VO2), arterial pH, base deficit, and plasma epinephrine (EPI) and norepinephrine (NEPI) concentrations in four control animals (Group 1) and in four animals receiving 140 mg/kg aminophylline intravenously (Group 2). Group 2 animals developed a significant rise in VO2 as compared to controls (P less than .01). Although left ventricular stroke work index was less in Group 2 animals (P less than .01), the sum of the total amount of ventricular work performed by both ventricles per minute did not differ between the two groups (P greater than .15). There was a marked increase in circulating levels of EPI (P less than .01) and NEPI (P less than .01) in Group 2 animals, along with the development of a metabolic acidosis. Catecholamines, which have been shown to produce tachyarrhythmias, increased VO2, hypokalemia, and a metabolic acidosis, may play an important role in the cardiovascular and metabolic effects seen in theophylline poisoning.