大鼠泻剂结肠肠壁神经生长因子受体p75的表达及其意义

背景：神经生长因子（NGF）及其受体与肠神经系统关系密切，演剂结肠有肠壁神经丛损害，但NGF受体p75在泻剂结肠中的表达和作用尚不明确。目的：研究NGF受体p75在正常大鼠和泻剂结肠大鼠中的表达及其在泻剂结肠形成中的意义。方法：采用大黄和酚酞建立泻剂结肠大鼠模型，以墨汁推进试验测定其传输功能：采用免疫组化法对正常大鼠和泻剂结肠大鼠的结肠肠壁进行p75检测。观察其在肠壁中的分布和表达情况。结果：与对照组相比，模型组肠道传输功能明显减慢，大黄组和酚酞组黑染肠管长度和百分比（黑染肠管长度／肠管总长度）均较对照组显著减低（P〈0．01，P〈0．05）。p75存正常大鼠结肠黏膜下神经丛中呈阳性表达，在肌间神经丛中多呈弱阳性表达。大黄组中p75表达明显增强，黏膜下神经丛亦呈强阳性表达，与对照组相比有显著差异（P〈0．01）；肌间神经从中多呈阳性表达（P〈0．05）。酚酞组黏膜下神经丛呈阳性表达，肌间神绎丛3只呈阳性表达，余表现为弱阳性或阴性，与对照组相比无明显差异。结论：p75在泻剂结肠中的异常表达可能参与肠神经丛冲经元细胞的退化变性或凋亡．从而引起泻剂结肠的肠神经系统病理变化，进一步导致结肠动力异常。这种损害与长期应用刺激性泻剂有关。     

肠神经调控的分泌功能及其在功能性肠病发病中的作用

一、肠神经系统-胃肠道的"大脑" 肠神经系统(ENS)分布于自食管至肛门的消化道管壁内.由神经节和节问神经纤维形成的肌间神经丛(MP)和黏膜下神经丛(SMP)组成.     

慢传输型便秘患者结肠中五羟色胺受体亚型的表达及意义

目的:研究主要5-HT受体亚型在慢传输型便秘(slowtransitconstipation,STC)患者结肠中的表达,探讨其在慢传输型便秘发病机制中的作用.方法:采用免疫组化EnVision法,检测20例STC患者和20例对照组结肠组织中5-HT1A,5-HT3和5-HT4受体的分布及表达水平,并采用IMS计算机辅助图像分析系统进行半定量分析.结果:5-H1A受体分布于黏膜下层、肌层,肌间神经丛5-HT1A受体的表达在STC组和对照组间无显著差异(P=0.548).5-HT3受体分布于黏膜下层和肌层,肌间神经丛STC组阳性指数显著低于对照组(65.2±15.9vs94.3±20.1,P<0.01).5-HT4受体分布于黏膜层、黏膜下层、肌层.在黏膜层和肌间神经丛,STC组5-HT4受体阳性指数均显著低于对照组(57.8±10.9vs78.5±12.9,P<0.01;77.5±19.9,119.2±26.9,P<0.01).STC组中,5-HT3受体表达水平与结肠传输试验第5天体内残留标志物数量无关(P>0.05);但5-HT4受体表达水平与第5天体内残留标志物数量呈负相关(r=-0.782,P<0.01).结论:STC患者结肠中存在5-HT3和5-HT4受体亚型的表达下调,两者可能参与了STC的发病机制.     

脑源性神经营养因子在肠道中的表达及其作用

脑源性神经营养因子(BDNF)既是一种神经营养物质又是一种神经递质,BDNF及其受体在肠神经系统、肠黏膜上皮和肠肌层中均大量表达,并在肠道感觉和肠道动力调节中起重要作用。本文就BDNF在肠道中的表达及其作用作一综述。     

慢传输型便秘结肠神经病理改变的意义

目的研究慢传输型便秘结肠肌间神经丛的神经丝蛋白和S-100蛋白的病理改变,探索结肠动力减弱的原因,为临床治疗提供理论依据.方法采用免疫组织化学方法研究33例结肠慢传输型便秘患者(STC组)和25例非便秘性结肠(对照组)的升结肠、横结肠、降结肠、乙状结肠的肌间神经丛内神经丝蛋白和S-100蛋白的表达,利用计算机图象分析系统作定量分析,并与病程及年龄作直线相关性分析.所得数据用t检验进行统计学处理.结果对照组结肠肌间神经丛内神经丝蛋白和S-100蛋白的含量在各段之间无显著性差别(0.09±0.03vs0.10±0.02,P＞0.05),STC组结肠各段与对照组比较,神经丝蛋白的平均光密度值明显高于对照组(0.12±0.03vs0.09±0.02,P＜0.01);S-100蛋白的含量及平均光密度值明显高于对照组(0.10±0.04vs0.08±0.03,P＜0.01).神经丝蛋白和S-100蛋白的改变随着病程的延长而增加,二者呈直线相关(r=0.75).结论慢传输型便秘结肠肌间神经丛存在着全结肠性退行性病理改变,表现为神经丝蛋白的堆积聚集和神经间质的增生,且随着病程的延长而加重,这是造成结肠动力减弱的主要原因.提示,手术切除结肠的范围应是全结肠或次全结肠.     

交感神经和肌间神经丛在胃电刺激调控胃慢波中的作用

目的研究胃交感神经及肌间神经丛在电刺激调控胃慢波活动中的作用,确定胃电起博的神经机制和作用环节,为今后起搏器的深入研究打下基础。方法10只雄性wistar大鼠随机分为对照组和电刺激组,各5只。全部大鼠植入浆膜电极,电刺激组大鼠行胃电刺激至胃慢波被完全控制。植入电极组不行电刺激。采用免疫组化S P法检测并比较两组大鼠胃窦肌间神经丛和脊髓后角C fos蛋白表达。结果电刺激组大鼠胃慢波全部被完全控制,所需能量为2 70±80 .6ms ,2mA。2组大鼠脊髓中间内侧核,中间外侧核均未见C fos阳性神经元,而后角浅层均见散在C fos表达,比较无显著性差异(P >0 .0 5 )。植入电极组胃窦肌间神经丛未见C fos阳性神经元,电刺激组胃窦肌间神经丛可见C fos阳性神经元。结论适宜参数的胃电刺激可完全控制大鼠胃慢波。肌间神经丛参与胃电刺激调控胃慢波,而交感神经则无明显作用。     

糖尿病大鼠回肠肌间神经丛mGluR1及mGluR5的表达

目的:了解糖尿病大鼠胃肠动力障碍时,回肠肌间神经丛有无形态学异常,以及第Ⅰ组代谢型谷氨酸受体mGluR1、mGluR5的表达变化,探讨谷氨酸能神经在糖尿病胃肠病变发生中的作用.方法:40只大鼠随机分为糖尿病组和对照组,给与高脂饮食结合腹腔注射STZ 30mg/kg造糖尿病模型.运用肌间神经丛铺片观察谷氨酸能神经的分布及形态特征,并对其神经节和神经元进行定量研究.以及运用免疫荧光染色和RT-PCR方法观察大鼠回肠肠神经系统肌间神经丛的代谢型谷氨酸受体mGluR1、mGluR5的表达变化.结果:糖尿病大鼠肠神经系统肌间神经丛的谷氨酸能神经节和神经元的数目较对照组明显减少(mGluR1:4.5±3.1 vs 7.3±2.4;142.25±28.24 vs 175.34±34.83,均P＜0.05;mGluR5:4.3±2.1 vs 7.9±2.8.133.37±35.73 vs 168.34±32.66,均P＜0.05),荧光强度较对照组减弱(mGluR1:145.23±28.78 vs 167.72±30.56.均P＜0.05;mGluR5:141.54±18.46 vs 172.53±29.74.均P＜0.05),mGluR1、mGluR5受体mRNA表达减少(1.05±0.27 vs 1.43±0.47,0.95±0.30 vs 1.60±0.39.均P＜0.01).结论:糖尿病大鼠回肠肠壁的肌间神经丛的神经节和神经元数目减少,以及兴奋性递质受体mGluR1、mGluR5的表达减少是导致胃肠道肌层兴奋性降低,肌层收缩减弱,引起糖尿病胃肠病变的一个重要机制.     

应激对大鼠结肠神经系统nNOS表达的影响

目的:探讨应激对大鼠结肠神经系统nNOS表达的影响. 方法:SD大鼠30只随机分为对照组,应激组和L-NAME 组,采用水浸-束缚应激(WRS)动物模型,用免疫组织化学ABC法检测nNOS在大鼠结肠黏膜下神经丛和肌间神经丛的表达,应用计算机图像分析系统对其表达进行定量分析．结果:与对照组比较,应激组黏膜下神经丛和肌间神经丛的nNOS阳性神经元的灰度值明显减少(P=0．02或P =0．005),阳性神经元细胞数的平均密度增加(P=0．04 或P=0．01),表达增强,且在黏膜上皮细胞、固有层淋巴细胞也有nNOS表达．L-NAME组黏膜下神经丛和肌间神经丛的nNOS阳性神经元的灰度值较应激组增加 (P=0．04),平均密度下降(P=0．04或P=0．03),表达减弱,而与对照组比较均无明显差异(P>0．05)．结论:应激可引起大鼠结肠神经系统nNOS表达增强, 提示一氧化氮(NO)在应激所致的结肠功能失调中可能起重要作用．     

肠道嗜铬细胞数量和5-羟色胺受体3表达在大鼠衰老过程中的变化及意义

目的 检测不同鼠龄SD大鼠肠道推进率、肠道黏膜嗜铬细胞数量和肠肌间神经丛5-羟色胺受体3(5-HT3R)的表达,探讨生理性衰老过程中肠道运动功能变化的规律及其机制. 方法 80只健康SD大鼠分为3月龄、9月龄、18月龄、24月龄及30月龄5组,每组各16只.以印度墨汁为标记物,检测大鼠的肠道推进率;采用免疫组化链霉亲和素-生物素-过氧化物酶复合物(SABC)法染色,检测大鼠空肠、回肠和结肠黏膜及黏膜下嗜铬细胞的数量以及肠肌间神经丛5-HT3R的表达.结果肠道推进率30月龄组大鼠为(52.1±9.8)%,明显低于3月龄组(67.2±13.5)%(t=7.013,P=0.001);30月龄组大鼠空肠、回肠及结肠黏膜和黏膜下嗜铬细胞数量分别为(11.1±3.0)个、(10.6±1.9)个和(10.2±4.3)个,较3月龄组(22.9±6.2)个、(25.8±7.1)个和(23.0±5.7)个减少(t=3.640,t=3.384,t=4.154,均为P<0.01);大鼠空肠和结肠的5-HT3R表达30月龄组分别为4.8±1.4和9.3±4.2,较9月龄组的8.9±1.5和14.5±5.3减少(t=3.464,t=3.003,均为P<0.01),回肠5-HT3R 30月龄组和3月龄组分别为5.0±1.3和9.0±1.7(t=4.549,P<0.001). 结论 老年大鼠肠道推进率、肠道嗜铬细胞数量及肠肌间神经丛5-HT3R表达均显著降低,并随年龄增长而逐渐明显;老年大鼠肠道运动功能的明显下降与肠嗜铬细胞数量以及肌间神经丛5-HT3R的表达显著降低有一定的相关性.     

胃电节律失常大鼠胃窦肌间神经丛胆碱能神经的改变

目的：探讨大鼠胃窦肌间神经丛胆碱能神经，氮能神经含量变化与胃电节律失常的关系。方法：63例大鼠随机分为正常对照组，胃电节律失常模型组和白芍组。饲养4周后记录并分析胃电信号，测定胃窦肌间神经丛胆碱能神经含量。结果：模型组胃电节律失常明显增加，胃窦肌间神经丛胆碱能神经含量减少；经白芍治疗后，胃电节律失常明显减少，胃窦肌间神经丛胆碱能神经含量恢复正常。结论：胃窦肌间神经丛的胆碱能神经与胃电节律关系密切，当胆碱能神经减少时，胃电节律失常明显增加。     

Oligoneuronal Hypoganglionosis in Patients with Idiopathic Slow-Transit Constipation

PURPOSE: Several alterations of the enteric nervous system have been described as an underlying neuropathologic correlate in patients with idiopathic slow-transit constipation. To obtain comprehensive data on the structural components of the intramural nerve plexus, the colonic enteric nervous system was investigated in patients with slow-transit constipation and compared with controls by means of a quantitative morphometric analysis. METHODS: Resected specimens were obtained from ten patients with slow-transit constipation and ten controls (nonobstructive neoplasias) and processed for immunohistochemistry with the neuronal marker Protein Gene Product 9.5. The morphometric analysis was performed separately for the myenteric plexus and submucous plexus compartments and included the quantification of ganglia, neurons, glial cells, and nerve fibers. RESULTS: In patients with slow-transit constipation, the total ganglionic area and neuronal number per intestinal length as well as the mean neuron count per ganglion were significantly decreased within the myenteric plexus and external submucous plexus. The ratio of glial cells to neurons was significantly increased in myenteric ganglia but not in submucous ganglia. On statistical analysis, the histopathologic criteria (submucous giant ganglia and hypertrophic nerve fibers) of intestinal neuronal dysplasia previously described in patients with slow-transit constipation were not completely fulfilled. CONCLUSION: The colonic motor dysfunction in slow-transit constipation is associated with quantitative alterations of the enteric nervous system. The underlying defect is characterized morphologically by oligoneuronal hypoganglionosis. Because the neuropathologic alterations primarily affect the myenteric plexus and external submucous plexus, superficial submucous biopsies are not suitable to detect these innervational disorders.     

心房颤动去神经治疗的临床效应

构成心脏自主神经系统的交感神经与迷走（副交感）神经在房颤（AF）的发生与维持中起着重要的作用,由此以心房神经丛（GP）消融为主的去神经治疗亦成为AF单独或辅助的介入疗法之一。然而GP消融带来的神经与心房重构现象也日益受到关注。     

神经生长因子在多次盐酸灌注食管气道高反应豚鼠肺组织中的表达

目的观察多次盐酸灌注豚鼠食管对呼吸道黏膜内神经生长因子（nerve growth factor,NGF）物质表达的影响。方法将20只豚鼠按随机数字表法分为2组,每组10只。①模型组：用盐酸氯胺酮将豚鼠轻度麻醉,将5F胃管插入豚鼠食管至食管中下端,灌注含0．5％胃蛋白酶的盐酸（0．1mol／L,8滴／min,20min／d）,连续灌注14d;②对照组：用PBS代替盐酸灌注食管,方法同上。用免疫组织化学方法测定两组豚鼠肺组织NGF的免疫反应变化;用免疫印迹法（Western blotting）检测肺组织NGF的免疫反应变化;Metamoph图像分析系统对结果进行分析。结果免疫组织化学结果显示（染色反应强度用灰度值表示）：模型组豚鼠气管和细支气管黏膜内NGF物质阳性反应的平均灰度值明显地低于对照组[（108．46±9．89）vs（135．86±4．01）]（P〈0．01）。Western blotting显示NGF在模型组豚鼠的肺内平均相对光密度值明显强于对照组[（1．415±0．155）vs（0．550±0．039）]（P〈0．01）。结论多次盐酸灌注豚鼠食管后呼吸道黏膜内NGF物质表达明显增多,提示NGF可能参与胃食管反流性呼吸系统疾病的发病过程。     

Direct spread of reovirus from the intestinal lumen to the central nervous system through vagal autonomic nerve fibers.

A crucial event in the pathogenesis of systemic enteric virus infections is entry of virus into the nervous system. Whether enteric virus spreads from the intestinal tract to the central nervous system through nerves or through the bloodstream was examined using a serotype 3 reovirus strain. After peroral inoculation of newborn mice with reovirus, serial histologic sections of small intestine, brain and spinal cord were prepared and stained by immunoperoxidase to detect viral antigen. Three days after inoculation, viral antigen was observed in mononuclear cells of ileal Peyer's patches and in neurons of the adjacent myenteric plexus. Infection first appeared in the central nervous system 1-2 days later in neurons of the dorsal motor nucleus of the vagus nerve. Endothelial cells, meninges, choroid plexus, hypothalamus, and area postrema were not infected, indicating neural rather than bloodborne spread from the intestine. Staining of neurons in the dorsal motor nucleus of the vagus nerve depended on the route of virus inoculation and was independent of the amount of virus in the bloodstream. These results demonstrate that an enteric virus entering a host from the intestinal lumen can spread to the central nervous system through nerve fiber innervating the intestine.     

Reaggregation of Rat Dissociated Myenteric Plexus in Extracellular Matrix Gels

The aim of this study was to investigate the growth behavior of freshly dissociated myenteric plexus in a three-dimensional extracellular matrix (ECM) environment with and without stimulation of glial cell line-derived neurotrophic factor (GDNF). Therefore, cell suspensions of the dissected myenteric plexus of newborn rats were cultured in freshly prepared gels of commercially available mixtures of collagen, laminin, and hepatoglycans as a first step towards mimicking the natural environment of the myenteric plexus. The cultures were kept either in chemically defined serum-free medium alone or supplemented with GDNF. Cultures on polylysine-coated glass cover slips served as controls. Dissociated myenteric plexus grown on polylysine formed dense clusters of neurons with radially outgrowing nerve fibers, while the neurons cultured in the gel reaggregated to much smaller clusters. These contained, depending on the culture conditions, 2–10 neurons. The morphology of the network that was seen in the gels after a few days in vitro resembled very closely the in situ situation of the submucous plexus and the myenteric plexus in hypoganglionic children. Electron microscope investigations showed a high degree of organization with fiber bundles and vesicle-containing varicosities and growth cones. Independent of the method of culturing, GDNF obviously influenced the growth behavior of the dissociated plexus. The size of the ganglia was larger, and the secondary network denser when GDNF was supplemented. Moreover, the enteric neurons in the gel cultures tended to be larger in size when treated with GDNF. Three-dimensional cultures of dissociated myenteric plexus in an ECM gel might be a valuable tool towards the understanding of the formation of the enteric nervous system during development, especially considering pathological conditions such as Hirschsprungs disease or other dysganglionic diseases.     

Ultrastructure of rat duodenal myenteric plexus revealed by quick-freezing and deep-etching method

A quick-freezing and deep-etching (QF-DE) method was employed with whole-mount strips of rat duodenal muscle walls to exhibit the cytoskeletons of the myenteric plexus. Nerve fibers in the myenteric plexus, which contained fewer neurofilaments than other types of neurons examined, had many varicosed contours, and were bundled by enteroglial cells. Cytoskeleton arrays were rarely observed in the varicosed regions, where synaptic vesicles were often seen, although other nerve regions contained many neurofilaments running almost in parallel with the nerve fiber bundle. Enteroglial cells had short cytoskeletons predominantly across the cytoplasm, becoming thinner the around varicosed regions of the nerve bundles. Such enteroglial extruded areas were often in close association with neighboring nerve fibers, indicating intercommunications between the nerve fibers. In distal parts of enteric nerve processes, there were numerous synaptic vesicles, but few neurofilaments. Smooth muscle cells were closely associated with the enteric nerve processes. Fine network structures, responsible for the extracellular matrix, were present between the smooth muscle cells and the enteric nerve processes. These specific structures of the myenteric plexus could be important for signalling or for the transportation of neurotransmitters involved in gut motility. (Received Feb. 25, 1998; accepted July 6, 1998)     

Neurochemical coding in the small intestine of patients with Crohn''s disease.

BACKGROUND: There have been conflicting results regarding the effect of Crohn's disease on the neurochemical composition of the enteric nervous system. AIMS: To examine the effect of Crohn's disease on the neurochemical composition of enteric nerve fibres and cell bodies using whole mount preparations of human ileum. METHODS: Whole wall ileum from seven normal subjects and nine patients with Crohn's disease was used to investigate the neurochemical composition of neurones and nerve fibres in the myenteric plexus, circular muscle, and serosa layer of ileum using immunohistochemical techniques. RESULTS: Increased tyrosine hydroxylase, 5-hydroxytryptamine, and neuropeptide Y immunoreactivity was exclusively seen in the myenteric plexus. There was increased neurofilament immunoreactivity in the myenteric plexus and nerve fibres of the circular muscle layer, and thick bundles of immunoreactive nerve fibres in the serosa layer. Increased vasoactive intestinal polypeptide, nitric oxide synthase, and pituitary adenylate cyclase activating peptide immunoreactivity was seen in the myenteric plexus and nerve fibres of the circular muscle layer, and aggregates of inflammatory cells in the serosa layer of the afflicted segment of Crohn's ileum. In addition, there was a chaotic display of nerve fibres containing some of the neuroactive substances with a high frequency of enlarged varicosities in the myenteric ganglia and/or nerve fibres of the circular muscle layer of Crohn's ileum. CONCLUSION: Results show quantitative as well as qualitative changes in the neurochemical composition of enteric nerve fibres and nerve cell bodies of Crohn's ileum. These changes and the presence of nitric oxide synthase and peptides immunoreactive inflammatory cells in the serosa layer suggest that nerve-immune interactions may have a significant role in the process of the inflammatory changes seen in Crohn's ileitis.     

A model of lytic, latent, and reactivating varicella-zoster virus infections in isolated enteric neurons

Because human primary afferent neurons are not readily obtained, we sought to develop a model in which the lytic, latent, and reactivating phases of varicella-zoster virus (VZV) infection were recapitulated in neurons from an animal source. Enteric neurons were obtained from the small intestine of adult guinea pigs and from the bowel of fetal mice. Latency was established when these neurons were infected by cell-free VZV in the absence of fibroblasts or other cells of mesodermal origin. In contrast, lytic infection ensued when fibroblasts were present or when the enteric neurons were infected by cell-associated VZV. Latency was associated with the expression of a limited subset of viral genes, the products of which were restricted to the cytoplasm. Lysis was associated with the expression of viral glycoproteins, nuclear translocation of latency-associated gene products, and rapid cell death. Reactivation was accomplished by expressing VZV open reading frame (ORF) 61p or herpes simplex virus ICP0 in latently infected neurons. Isolated enteric neurons from guinea pigs and mice recapitulate latent gene expression in human cranial nerve and dorsal root ganglia. Expression of latency-associated VZV gene products was detected in 88% of samples of adult human intestine, suggesting that VZV not only infects enteric neurons but also is latent in the human enteric nervous system. This in vitro model should facilitate further understanding of latency and reactivation of VZV.     

cGMP信号传导通路及钙敏感钾通道在D型钠尿肽抑制豚鼠胃动力中的作用

目的观察豚鼠胃内是否存在钠尿肽（NP）受体,并观察cGMP信号传导通路及钙敏感钾通道在D型钠尿肽（DNP）抑制豚鼠胃动力中的作用。方法用放射自显影技术检测NP受体在胃内的分布,用四道生理记录仪记录胃平滑肌的自发性收缩活动,用膜片钳技术的全细胞技术记录钙敏感钾电流。结果 NP受体存在于豚鼠胃底、胃体和胃窦,并在胃窦部密度最大。DNP抑制胃窦环形肌自发性收缩活动并呈现剂量依赖关系,DNP的这种抑制效应被鸟苷酸环化酶抑制剂LY83583所减弱而被cGMP敏感的磷酸酯酶抑制剂所增强。非选择性钾通道抑制剂四乙胺明显抑制DNP对豚鼠胃窦环形肌自发性收缩活动的抑制作用。10 nmol/L的DNP增加豚鼠胃窦环形肌上钙敏感钾通道。结论 NP受体存在于豚鼠胃内并在胃窦部位分布密度最大,DNP明显抑制豚鼠胃窦环形肌自发性收缩活动,这种抑制效应可能通过cGMP途径实现,并且钙敏感钾通道可能也参与此过程。