应激状态下大鼠结肠血红素氧合酶-2的表达

目的:探讨血红素氧合酶-2（HO-2）在正常及应激状态下大鼠结肠的表达及其意义。方法:将30只SD大鼠随机分为对照组、应激组和应激+ZnPP组，采用水浸-束缚应激（WRS）动物模型，用免疫组织化学SABC法检测HO-2在正常及应激后大鼠结肠中的表达，通过计算机图像分析系统进行定量测定。结果:对照组大鼠HO-2主要表达于结肠黏膜肌、肠环行肌及黏膜下层的血管内皮和平滑肌。应激组大鼠结肠的HO-2免疫阳性黏膜肌灰度值明显少于对照组（P<0.05），环行肌阳性单位（PU）明显高于对照组（P<0.05），在部分大肠腺也有HO-2表达。应激+ZnPP组结肠HO-2免疫阳性黏膜肌灰度值明显高于应激组（P<0.05），环行肌PU低于应激组（P<0.05）。结论:一氧化碳（CO）是结肠重要的气体信号分子，可能参与应激状态下的结肠功能调节。     

肠易激综合征早期生活事件模型下的大鼠结肠肠神经可塑性研究

目的从神经可塑性角度探讨肠易激综合征的可能发病机制、临床特征及治疗方法。方法雄性SD大鼠出生后连续13 d每天分离3 h。腹壁撤退反射实验用来检测内脏痛觉过敏。肠神经系统结构可塑性可以通过铺片技术和免疫荧光技术,比较近端结肠神经节(HuD阳性细胞)的大小和数目以及胶质细胞(GFAP)的变化来检测。检测近端结肠多组肌间神经丛和黏膜下神经丛肠神经递质类型(ChAT-、VIP-、nNOS-、calbindin-TrKA-、P75-阳性细胞),分析神经递质的可塑性变化。结果新生期应激可致成年鼠内脏敏感性增高,新生期母婴分离可以诱导肠神经结构改变,导致神经元肥大和增生、胶质细胞与神经元的比例增高。神经递质方面,新生期母婴分离组P75和TrkA表达(黏膜下神经丛、肌间神经丛)较正常组均明显增加。ChAT在肌间神经丛表达明显增加,VIP在黏膜下神经丛表达降低,nNOS在肌间神经丛表达增高,Cabindin表达未见明显异常。结论新生期母婴分离可以引起大鼠结肠肠神经可塑性的长期改变。新生期母婴分离诱导的内脏高敏感性中存在肠神经系统可塑性。早期生活事件是引起成年后肠神经系统可塑性改变的重要原因。     

电针对慢性应激大鼠海马神经元型一氧化氮合酶表达的影响

目的探讨电针（electroacupuncture,EA）对慢性应激海马神经元型一氧化氮合酶（nNOS）表达的影响。方法30只雌性SD大鼠随机分成3组：模型组、电针组和对照组。每组10只。模型组大鼠连续接受21d各种不同的应激,平均每种应激使用2～3次。电针组模型建立后中止刺激,给予电针“三阴交”穴和“百会”穴．连续电针21d。对照组不给予刺激和电针。第42天将3组大鼠处死取脑。利用免疫组织化学方法检测海马区nNOS的表达情况。结果模型组大鼠海马nNOS阳性神经元的数量减少（P〈0．05）,染色变淡;电针后海马nNOS阳性神经元的数量有所增加（P〈0．05）。结论电针可上调nNOS在大鼠海马内的表达。     

急性应激对大鼠纹状体nNOS表达及分布的影响

目的:研究应激对大鼠纹状体内神经型一氧化氮合酶(neuronal nitric oxide synthase,nNOS)表达和分布的影响。方法:建立大鼠运输应激模型(120 r/min,持续2 h),将24只大鼠随机分为对照组和应激组。应用Western Blot分别测定对照组和应激组大鼠脑内nNOS的表达量并结合免疫细胞化学染色探察应激前后纹状体nNOS神经元的分布及其形态学特征的变化。结果:Western Blot结果显示应激后nNOS在蛋白水平上显著提高(P0.05);免疫组化染色显示nNOS阳性神经元在纹状体呈散在分布,可见棕色免疫阳性物质主要位于细胞质中,细胞核着色浅,细胞轮廓清晰,突起明显;与对照组相比,应激组阳性细胞数显著增多(P0.05),且着色较深。结论:应激使大鼠纹状体内nNOS表达显著增多,nNOS的升高可能是引起运输焦虑的深层原因之一。     

慢性疲劳应激对大鼠伏隔核一氧化氮合酶表达的影响

目的:探讨长时间游泳引起的疲劳应激对大鼠伏隔核(NAc)中神经元型一氧化氮合酶(nNOS)表达的影响.方法:采用成年雄性大鼠连续4周每天强迫游泳至力竭,用免疫组织化学方法结合图像处理测定伏隔核中nNOS的表达.结果:长时间强迫游泳应激可使大鼠伏隔核巾nNOS免疫细胞化学反应阳性神经元的数量(106.7%)、面积(150.2%)和灰度值(11.3%)显著增加.结论:nNOS参与疲劳应激的形成,一氧化氮在伏隔核对应激调节中起重要作用.     

人参皂甙对Alzheimer病模型大鼠海马生长抑素mRNA表达的影响

目的：研究人参皂甙（GS）对Alzheimer病（AD）模型大鼠海马内生长抑素（SS）mRNA表达的影响。方法：本实验以D-半乳糖致衰老合并鹅膏蕈氨酸脑内Meynert核注射建立AD大鼠模型,运用原位杂交方法结合图像分析检测各组大鼠海马SSmRNA表达。结果：模型组大鼠海马各区SSmRNA表达阳性神经元平均灰度值比正常对照组明显升高,平均密度显著降低;而预防组、治疗组阳性神经元灰度值则比模型组显著降低,平均密度明显升高;正常对照组与人参皂甙对照组大鼠的CA4及DG区中,此两项指标差异显著。结论：GS对AD模型大鼠海马SSmRNA表达减弱有预防及治疗作用。     

便秘型肠易激综合征大鼠胃排空及胃内肠神经系统的变化

 目的 观察便秘型肠易激综合征（IBS-C）模型大鼠胃排空及胃肌间神经丛神经元总数、乙酰胆碱转移酶（ChAT）阳性神经元、一氧化氮合酶（NOS）阳性神经用。方法 冰水灌胃法制作IBS-C模型大鼠（n＝7），设对照组；采用酚红排空定量法测定胃排空率；取远端胃组织制作石蜡切片标本，采用抗神经核抗体（anti-Hu）标记神经元总数， Hu/ChAT、Hu/NOS抗体行免疫组织荧光双染色，观察、计算特异性阳性神经元占神经元总数百分比。结果 冰水灌胃组大鼠胃排空率显著高于对照组（P<0.05）。IBS-C模型大鼠ChAT阳性神经元显著高于对照组（79.0% ± 2.4%比68.3 % ± 1.0%，P<0.05），NOS阳性神经元显著低于对照组（18.9% ± 5.0%比33.1% ± 4.5%，P<0.01）。结论 冰水灌胃法制作的IBS-C模型大鼠胃排空及胃肌间神经丛神经元均存在改变，表明肠神经系统的变化可能是功能性胃肠病重叠综合征发病机制之一。     

Nogo-A在大鼠胃肠神经丛中的表达

目的：探讨Nogo-A蛋白在成年大鼠胃肠神经丛中的表达。方法：利用免疫组织化学法,观察Nogo-A蛋白在大鼠胃肠神经丛中的表达,并用RT—PCR检测Nogo-AmRNA在胃肠组织中的表达情况。结果：在成年大鼠胃肠神经丛,包括黏膜下神经丛、肌间神经丛、浆膜下神经丛内的神经元出现Nogo-A免疫反应阳性,胞质和胞核都可见棕褐色颗粒;胃肠组织的RT—PCR结果显示Nogo-AmRNA为阳性。结论：Nogo-A可广泛表达于各器官系统的神经元中,提示Nogo-A的功能可能与神经元的某个共同的生理活动有关。     

肌源神经营养因子（MDNE）对体外培养大鼠脊髓神经元划伤后Bcl—2表达的影响

为检测大鼠肌源神经营养因子对体外培养大鼠脊髓运动神经元划痕损伤后Bcl-2表达的影响，本实验从成鼠和乳鼠骨骼肌中提取出肌源神经营养因子。在胎鼠脊髓运动神经元培养第7d时将其随机分成对照组和实验组（成鼠组和乳鼠组），取100μl肌源神经营养因子（0.1μg/ml)加入实验组，对照组加入等量的PBS，同时进行划痕损伤。损伤后第3d计数各组存活的运动神经元，行Nissl染色和免疫组化反应，计数Bcl-2免疫反应（Bcl-2－IR）阳性神经元数量，并在图像分析仪上对Bcl-2－IR阳性神经元作光密度分析。结果发现，损伤后第3d，实验组运动神经元存活数，Bcl-2-IR阳性神经元数和平均光密度均明显高于同期对照组，而乳鼠肌源神经营养因子组功效优于成鼠肌源神经营养因子组。结果提示，大鼠肌源神经营养因子对体外培养的受损运动神经元具有增强Bcl-2表达，减少凋亡和损伤修复等作用，且乳鼠的此因子效能尤佳。     

NO合酶阳性神经元在便秘型肠易激综合征大鼠结肠的表达

目的:探索一氧化氮合酶(NOS)阳性神经元在便秘型肠易激综合征(C-IBS)大鼠结肠的分布特点及变化。方法:冷水持续灌胃15 d制作C-IBS大鼠模型。通过对大鼠大便性状和结肠内膨胀刺激后腹肌反应的观察及结肠HE染色对模型进行评价。免疫荧光组织化学和Western Blot观察NOS阳性神经元在结肠肠肌丛的分布及改变。结果:造模15 d后,模型组大鼠大便呈腊肠状的碎块,结肠的腹肌反应阈值明显降低,HE染色显示结肠粘膜层完整。免疫荧光组织化学显示,C-IBS大鼠结肠肠肌从神经元NOS表达较对照组明显增高。Western Blot结果显示,C-IBS大鼠结肠NOS的表达明显增加。结论:NO在C-IBS大鼠结肠神经元内表达增加,此异常可能与C-IBS大鼠结肠运动功能紊乱相关。     

Immunohistochemical studies of the enteric nervous system in tissue culture and in situ: localization of vascoactive intestinal polypeptide (VIP), substance-P and enkephalin immunoreactive nerves in the guinea-pig gut

Immunofluorescence methods have been used to determine the detailed distribution of vasoactive intestinal polypeptide (VIP), substance-P and enkephalin nerve fibres in fixed cryostat sections from guinea-pig duodenum, jejunum, ileum, caecum at the site of the taenia coli, and proximal and distal colon. A novel method is used involving immunostaining of tissue culture preparations of both myenteric and submucous plexuses. These preparations allow each plexus to be studied in isolation from all axonal input for the first time, since they provide unequivocal extrinsic denervation together with severance of any intrinsic connections between the plexuses. In tissue sections the most prominent sites of VIP and substance-P immunoreactive fibres are the ganglia of the myenteric and submucous plexuses, the circular muscle layer and the longitudinal muscle of the taenia coli. In addition, VIP is prominent in the lamina propria of the submucosa except in the caecum. Enkephalin-immunopositive fibres are restricted to the ganglia of the myenteric plexus, the circular muscle layer and the longitudinal layer of the taenia coli. The culture preparations reveal that intrinsic ‘VIP neurons’ are common in the submucous plexus of the caecum and colon. They are also present, but in much lower numbers, in the myenteric plexus of the small intestine and colon but are not found in the myenteric plexus of the caecum. Intrinsic ‘substance-P neurons’ are present in the myenteric plexus from the small intestine, caecum and colon as well as in the submucous plexus of the colon; intrinsic ‘substance-P neurons’ are not found in the submucous plexus of the caecum. ‘Enkephalin neurons’ are numerous in the myenteric plexus of the small intestine, caecum and colon but are absent from the submucous plexus. Immunoreactivity is compared in the normal and denervated caecum by both the histochemical method and by radioimmunoassay of tissue extracts. In conjunction with the studies on tissue cultures, the results provide evidence for intrinsic reciprocal connections between the myenteric and submucous plexus of the caecum by neurons containing VIP and substance-P.An extensive comparison of these results with data from functional studies shows that the distribution of VIP, substance-P and enkephalin fibres in the gut is broadly in agreement with present knowledge of the action of these peptides on gut tissue, if it is assumed that they function as neurotransmitters or neuromodulators. In some instances, however, peptide-containing fibres and pathways are found which do not correlate with present knowledge obtained from functional studies. These observations provide new clues to the role of peptide neurons in gut function.     

The origins,pathways and terminations of neurons with VIP-like immunoreactivity in the guinea-pig small intestine

We have analyzed changes in the distributions of terminals with vasoactive intestinal polypeptide (VIP)-like immunoreactivity, and accumulations in severed processes, that occur after lesions of intrinsic and extrinsic nerve pathways of the guinea-pig small intestine. The observations indicate that enteric vasoactive intestinal polypeptide immunoreactive neurons have the following projections. Nerve cell bodies in the myenteric plexus provide varicose processes to the underlying circular muscle; the majority of these pathways, if they extend at all in the anal or oral directions, do so for distances of less than 1 mm. Nerve cell bodies of the myenteric plexus also project anally to provide terminals to other myenteric ganglia. The lengths of the majority of these projections are between 2 and 10 mm, with an average length of about 6 mm. Processes of myenteric neurons also run anally in the myenteric plexus and then penetrate the circular muscle to provide varicose processes in the submucous ganglia at distances of up to 15 mm, the average length being 9–12 mm. In addition, there is an intestinofugal projection of myenteric neurons whose processes end around nerve cell bodies of the coeliac ganglia. A similar projection from the colon supplies the inferior mesenteric ganglia. The nerve cell bodies in submucous ganglia give rise to a subepithelial network of fibres in the mucosa and also supply terminals to submucous arterioles.It is concluded that vasoactive intestinal polypeptide is contained in neurons of a number of intrinsic nerve pathways, influencing motility, blood flow and mucosal transport. The myenteric neurons that project to prevertebral sympathetic ganglia may be involved in intestino-intestinal reflexes.     

Distribution of enteric nerve cell bodies and axons showing immunoreactivity for vasoactive intestinal polypeptide in the guinea-pig intestine

Immunoreactivity for vasoactive intestinal polypeptide has been localized in neurons in the guinea-pig ileum, colon and stomach. In the ileum, 2.5% of the nerve cell bodies of the myenteric plexus and 45% of those of the submucous plexus showed vasoactive intestinal polypeptide-like immunoreactivity. Varicose axons containing vasoactive intestinal polypeptide ramified amongst the nerve cell bodies of both plexuses and in some cases formed rings of varicosities around non-reactive nerve cells. Axons were traced from the myenteric plexus to the circular muscle and deep muscular plexus. There were numerous positive axons running in fine strands within the circular muscle, parallel to the muscle bundles. Axons containing vasoactive intestinal polypeptide were associated with mucosal blood vessels, but few supplied the vascular network of the submucosa; some immunoreactive axons also contributed to the periglandular plexus of the mucosa. There were no changes in the distribution of axons in the ileum after extrinsic denervation.The results are discussed in relation to the possible functional roles of neurons that contain vasoactive intestinal polypeptide in the intestine: the distribution of such nerve cells in the myenteric plexus and of axons in the circular muscle and sphincters is consistent with this polypeptide being a transmitter of enteric inhibitory neurons; it is also possible that vasoactive intestinal polypeptide is the enteric vasodilator transmitter.     

豚鼠胃肠壁内神经丛的磷酸醋、醋类和神经递质代谢有关的酶组织化学观察

本文报道用光镜半定量和显微光度计定量分析研究了豚鼠胃肠壁内神经丛神经元的几种酶的组织化学反应。结果表明,神经元的碱性磷酸酶(AlP)、酸性磷酸酶(AcP)、5′-核苷酸酶(5′-Nase)、硫胺素焦磷酸酶(TPPase)、非特异性酯酶(NsE)和胆碱乙酰转移酶(ChAT)反应强弱明显不等。消化道不同节段或不同部位神经元的单胺氧化酶(MAO)、氨基肽酸(AP)和乙酰胆碱酯酶(AChE)反应虽有差别,但却显阳性反应,同一神经节内各神经元的反应比较近似。胃肠各段壁内神经丛中50～66%神经元呈ChAT强阳性反应,这些细胞可能为胆碱能神经元。整个消化道粘膜下丛与肠肌丛神经元相比,除NsE外,另几种酶均有高度显著差异。粘膜下丛神经元AcP和AP反应较强,肠肌丛神经元AlP、5′-Nase、TPPase、MAO、ChAT和AChE反应较强,胃壁内神经丛不如肠道的发达。尤其是胃粘膜下丛只见少数单个散在的神经元,它们的各种酶组织化学反应均较弱。各段肠中,以十二指肠和近端结肠壁内神经丛神经元的各种酶组织化学反应较强。上述结果表明,消化道不同部位以及同一部位不同类型的神经元在代谢和功能上有明显的差别。     

神经激肽A在大鼠结肠发育中的定性定量分析

探讨神经激肽A(NKA)在大鼠结肠发育中的表达及变化,应用免疫组织化学PAP法和图像分析系统观测大鼠胚胎13d至成年结肠中NKA的表达情况。结果显示:(1)在结肠,首先于胚胎17 d的肌间丛及上皮处出现NKA-IR的表达,随发育相继出现于纵肌、环肌、粘膜肌、固有膜、粘膜下层和粘膜丛,30 d时具备成年分布特征;(2)定量分析的结果与NKA~IR在结肠各层的变化一致;(3)NKA-IR细胞具有典型的肠道内分泌细胞的形态特征和分布特征。结果提示:(1)NKA在结肠的发生发育主要在生前5 d~生后4周内;(2)NKA在结肠的发生发育有两个关键时期,即生前5 d~生后1周和生后1月末;(3)NKA-IR细胞可能是肠道内分泌NKA的内分泌细胞;(4)NKA可能对大鼠结肠的发育具有重要作用,可能与结肠功能的建立密切相关。     

Projections and chemical coding of neurons with immunoreactivity for nitric oxide synthase in the guinea-pig small intestine.

The distribution of nitric oxide synthase (NOS) immunoreactivity was investigated in the guinea-pig small intestine. There were many immunoreactive nerve cell bodies in the myenteric plexus but very few in submucous ganglia. NOS immunoreactivity was not found in non-neuronal cells except for rare mucosal endocrine cells. Abundant immunoreactive nerve fibres in both myenteric and submucous ganglia, and in the circular muscle, arose from myenteric nerve cells whose axons projected anally along the intestine. NOS immunoreactivity coexisted with VIP-immunoreactivity, but not with substance P immunoreactivity. We conclude that nitric oxide synthase is located in a sub-population of enteric neurons, amongst which are inhibitory motor neurons that supply the circular muscle layer.     

Neuron density and distribution of NADPH-diaphorase positive neurons in the human stomach

Neuron density and distribution of the NADPH-diaphorase positive neurons were studied in the fundus, corpus and antrum of adult human stomach using cresyl violet staining and NADPH-diaphorase histochemistry. The submucous plexus contained significantly less neurons than the myenteric plexus. Submucous NADPH-d positive neurons were mostly located in ganglia close to the circular muscle layer. Myenteric NADPH-d positive neurons represented 50–60% of the neurons in all the three regions; their density, however, was significantly lower in the fundus. NADPH-d positive fibers formed a rich plexus in the innermost portion of the circular muscle layer of the corpus.     

An immunohistochemical study of the distribution of enteric GABA-containing neurons in the rat and guinea-pig intestine

gamma-Aminobutyric acid (GABA) antiserum was applied to sections of rat and guinea-pig intestine which were subsequently processed to reveal any immunoreactivity using either fluorescence or peroxidase techniques. Immunopositive fibres were demonstrated in stomach, duodenum, ileum and colon of rat and guinea-pig intestine. Myenteric ganglia and nerve bundles in the circular muscle contained immunopositive nerve fibres, while the longitudinal muscle, submucosa and mucosa were only rarely innervated. In favourable sections, immunopositive fibres could be seen running from the myenteric plexus into the circular muscle, thus suggesting that the GABA-immunopositive nerves in the circular muscle originate from neurons in the myenteric plexus. In both rat and guinea-pig, immunoreactive nerve cell bodies were most numerous in the myenteric plexus of the colon. In the rat, immunopositive fibres in the circular muscle were most abundant in the ileum, whereas in the guinea-pig it was the colon circular muscle that was most richly innervated. The results demonstrate that neurons which show GABA immunoreactivity are present along the length of the gastrointestinal tract. Their distribution in both myenteric ganglia and circular muscle is heterogeneous both within and between the two species studied. It is probable that this heterogeneity reflects the diversity and specificity of function of this class of enteric neurons.     

P2X2受体在大鼠胃肠系统肌间神经节中的分布

目的:研究P2X2受体在大鼠胃肠系统肌间神经节中的分布,为研究ATP作为神经递质对胃肠道肌间神经节节细胞的作用提供形态学基础。方法:免疫组织化学。结果:从胃到结肠均有P2X2受体阳性神经元和神经纤维分布,胃、小肠和结肠分别约60％、70％和50％的肌间神经节节细胞为P2X2受体阳性。结论:胃肠道系统多数肌间神经节节细胞都能通过ATP受体特别是P2X2受体对ATP产生反应。