μ阿片受体在大鼠结肠肠肌丛的神经化学特性

目的:探索μ阿片受体(MOR)在大鼠结肠肠肌丛的分布及化学神经解剖学特性。方法:取大鼠结肠右曲和左曲之间肠管行全层铺片,剥离粘膜层、粘膜下层和环形肌层,保留纵行肌层。运用免疫荧光组织化学双重标记技术染色,共聚焦显微镜下观察MOR在大鼠结肠肠肌丛的分布及与一氧化氮合酶(NOS)、肠血管活血肽(VIP)、P物质(SP)或降钙素基因相关蛋白(CGRP)等在肠神经细胞的共存关系。结果:免疫荧光组织化学染色显示:在大鼠结肠肠肌层,MOR阳性细胞聚集形成神经节,其阳性突起穿行于神经节之间形成网格状神经丛。在肠肌丛神经细胞内,可见MOR分别与NOS、VIP、SP、CGRP共存。MOR阳性神经纤维和终末分布于NOS阳性神经细胞周围,也可见部分NOS、VIP阳性神经纤维和终末分布于MOR阳性神经细胞表面。有大量SP和CGRP阳性神经纤维穿行于MOR阳性神经细胞之间并包绕于MOR阳性神经细胞的胞体周围。结论:在结肠的肠肌丛,MOR与抑制性和感觉性神经递质在肠神经细胞有共存,且相互之间有纤维联系,推测MOR可能介导了阿片类调节肠神经细胞内抑制性神经递质的释放,并可能对肠感觉信息的传递有调节作用。     

先天性巨结肠病肠壁NOS阳性神经元光镜和电镜观察

目的：探讨NOS阳性神经元与先天性巨结肠病病因及病理机制的关系。方法：对扩张段和移行段肠壁分别作全层铺片,NADPH－d酶组织化学染色,光镜和扫描电镜下观察NOS阳性神经结构。结果：扩张肠段光镜下肠肌丛神经节和神经元均较大,节内神经元染色深数量多,沿神经节周边及神经纤维发出处排列。扫描电镜下神经元胞体较大,排列较密,发出的神经纤维较多,在各个方向上相互连接。沿肌纤维排列的神经元之间有较多的横向连接纤维,肠肌丝社会元还通过穿行于环行肌层的神经纤维和粘膜下层神经元相连接,移行段光镜下节内神经元胞浆染色较淡,深浅不一,神经节和神经元均较小,发现的纤维细且染色较淡,扫描电镜下神经元胞形较小,且大小不等,密较较小,神经元间的纤维联系及神经纤维攀附于肌纤维表面的现象均较少,神经元和神经纤维呈沿纵行肌长轴线性分布。结论：先天性巨结肠病的发生及发展可与NOS阳性神经元在肠壁的分布与代谢异常有关关。     

猪食管神经支配的神经化学研究——一氧化氮类及肽类成分在平滑肌中的分布(英文)

采用免疫荧光组织化学技术及迷走神经切断术,探讨猪食管一氧化氮类及肽类神经支配的神经化学特性。在光学显微镜下可观察到肌间神经丛及粘膜下神经丛中有部分神经元呈nNOS、VIP、GAL、NPY、PACAP、L-ENK、SP、5-HT及CB免疫阳性,但未见CGRP及SOM阳性神经元。nNOS及CB免疫阳性产物主要分布于不同的神经元胞体内。将PGP9.5作为神经元胞体的标记物,并采用免疫荧光免疫组织化学双重染色方法,分别观察了PGP9.5与nNOS、VIP、SP的双标情况。结果如下:(1)nNOS免疫阳性神经元约占PGP9.5标记神经元总数的63%,而VIP免疫阳性神经元约占36%,SP免疫阳性神经元约占28%;(2)神经节内神经元的平均数量呈现吻尾方向的递增趋势,且食管腹段神经丛内神经节数量明显高于食管其他部位;(3)食管肌层内VIP/GAL/NPY免疫阳性纤维分布最广,其中部分阳性纤维同时呈nNOS或PACAP免疫阳性;SP和/或L-ENK免疫阳性纤维在粘膜肌层的分布明显多于平滑肌层。CGRP阳性纤维非常少见,这一点不同于对其他动物的观察结果;(4)经一侧迷走神经切断后,肌间神经丛内PACAP及5-HT免疫阳性纤维明显减少,提示这些纤维可能来源于迷走神经;而平滑肌中VIP/GAL/NPY和/或nNOS免疫阳性纤维数量未发现明显变化,可能为内源性来源。     

人胚胎结肠肠神经系统发育的观察

目的　研究人胚胎结肠肠神经系统的发育过程 ,为进一步研究先天性巨结肠的发病机制提供参考。　方法　采用一抗为蛋白基因产物 (protein gene product9.5 ,PGP9.5 )和 S- 10 0蛋白抗体的免疫组织化学 PAP法 ,显示结肠肠神经系统中的神经元和神经胶质。　结果　人胚胎结肠肠神经系统发育有明显的阶段性。在胚胎发育早期 (胎龄 2～ 3月 ) ,肠管壁发育差 ,以后出现菲薄的平滑肌层和低平的肠粘膜 ,此期偶在原始肌间神经丛位置见S- 10 0蛋白免疫反应性神经 ;至发育中期 (胎龄 4～ 5月 ) ,肠壁分化出 4层结构 ,出现相当发达的绒毛 ,肌间神经丛中细胞明显增多 ,呈弥散分布于整个肌层间并逐渐迁移到粘膜下层和粘膜层 ,由初级和次级突起构成复杂的神经网络 ;至晚期 (6～ 9月 ) ,肠壁各层均增厚 ,肌间神经丛成簇分布 ,神经纤维构成的网络出现更为细小的 3级突起 ,粘膜下神经丛分化形成浅丛和深丛。　结论　结肠神经系的发育具有明显的阶段性。发育早期神经开始在肠壁肌间丛位置出现 ,发育中期神经成分在肠壁各层中出现并发育增生 ,晚期肠壁各层神经已分化和成熟 ,而在不同的发育阶段 ,原始病因可导致临床表现不一的先天性巨结肠症     

发育中的人胎小肠神经肽的研究

目的　研究人胎小肠壁P物质 (SP)和降钙素基因相关肽 (CGRP) IR肽能神经的分布和发育规律。方法　苏木精伊红 (HE)染色和免疫组织化学ABC法。结果　在胎儿发育过程中 ,小肠组织形态及其神经肽的发生、分化出现明显的变化 ,其分化由十二指肠向空肠、回肠依次进行。第 14周开始 ,胎儿小肠壁粘膜下层、肌层间结缔组织中偶见SP能、CGRP能神经纤维及神经元免疫反应产物 ,第 34周至 38周时反应最强 ,神经元从浅棕色到深棕色 ,神经纤维呈串珠状或点线状。从SP、CGRP免疫组织化学相邻切片上看 ,两者部分存在共存现象。结论　人胎小肠壁存在SP IR、CGRP IR肽能神经 ,粘膜下和肌间神经丛存在SP IR、CGRP IR肽能神经元和神经纤维 ,二种神经肽的分布有差异     

扬子鳄大肠和输尿管的神经肽分布

目的:观察扬子鳄大肠的神经肽Y（neuropeptide Y,NPY）、血管活性肠肽（vasoactive intestinal peptide,VIP）和输尿管的P物质（substance P,SP）、血管活性肠肽分布。方法:免疫荧光方法。结果:扬子鳄大肠的NPY和VIP免疫反应（NPY-and VIP-immunoreactive,NPY和VIP-IR）阳性神经纤维皆呈弯曲的细线状,主要位于粘膜下层,其次为浅部肌层,且在粘膜下层NPY-IR神经纤维交织成密集的神经丛;VIP-IR神经纡维在粘膜下层构成稀疏的网络状。输尿管的SP免疫反应（SP-immunoreactive,SP-IR）和VIP-IR神经纤维均呈点线状;其中,SP-IR神经纤维位于外膜层,较稀疏,VIP-IR神经纤维位于肌层,较密集,纤维间可见两个近似圆形的VIP-IR阳性神经细胞体。结论:扬子鳄大肠和输尿管分别存在有NPY、VIP和SP、VIP神经分布。     

人空肠NPY能神经分布的研究

本文用免疫组织化学ABC法,对神经肽Y(NPY)能神经纤维和神经元在人空肠壁内的分布进行了研究.结果:NPY能神经纤维和神经元呈棕褐色;NPY能神经纤维遍布肠壁各层,位于粘膜固有层内的神经纤维在小肠腺周围交织或疏网状.NPY能神经元见于肌间及粘膜下神经丛,尤以后者为多.粘膜内也可见NPY能神经元,它们分布于小肠腺下方,紧靠粘膜肌,或位于粘膜肌内.     

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。     

扬子鳄消化管壁内粘膜下神经丛的形态学观察

消化管神经丛的分布及其生理活动的研究甚多,但对低等脊椎动物的研究报道较少.扬子鳄是我国特有的世界珍稀动物,本文用Karnovsky-Roots乙酰胆碱酯酸(AChE)组化法研究扬子鳄消化管粘膜下神经丛的分布,为肠神经丛的比较解剖学研究提供一些形态学资料.1 材料和方法 扬子鳄2条(雌雄各1),2%戊巴比妥钠10～15ml腔内注射麻醉,打开胸腹腔,从左心室灌注生理盐水,继而灌流4%多聚甲醛固定,取食管下段、胃体、十二指肠、空肠、回肠和大肠,置4%多聚甲醛固定6h,继入合20%蔗糖的0.1mol·L~(-1)PB液中,4℃过夜.制备厚25μm的冷冻切片.以亚铁氰化铜法显示AChE,孵育液内加四异丙基焦磷酰胺(iso-OMPA)非特异性胆碱酯酶抑制剂和免去底物为对照.     

扬子鳄食管颈段一氧化氮合酶(NOS)阳性神经元及神经纤维的分布

本实验采用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶(NADPH-d)方法,观察扬子鳄食管颈段NOS阳性神经元和神经纤维的分布.结果食管颈段的粘膜下层和肌层分布着较丰富的NOS阳性神经纤维,一些神经纤维交织成丛状,其间散在分布着NOS阳性神经元胞体.粘膜下一些NO S阳性神经丛环绕血管壁走行.     

中华蟾蜍消化道内分泌细胞的分布与形态

目的:对中华蟾蜍消化道5种内分泌细胞的分布与形态进行研究.方法:对中华蟾蜍消化道各段取材,应用免疫组织化学SP法结合生物统计学分析.结果:生长抑素细胞在消化道各段均有分布,以胃幽门部密度最高,空肠和胃贲门部其次.回肠和直肠中密度最低.胃泌素细胞主要分布于胃和肠道各段,胃幽门部和空肠密度较高,食道中无分布.胰高血糖素细胞主要分布于胃,以胃幽门部密度最高.肠道只在十二指肠处偶见.胰多肽细胞在消化道各段均未见分布.血管活性肠肽细胞主要分布于胃体、胃幽门部、回肠和直肠,以直肠中密度最高.结论:中华蟾蜍内分泌细胞的分布型与其摄食习性是相适应的.     

Acetylcholine and substance P responsiveness of intestinal smooth muscles in streptozotocin diabetic rats

We found previously that in in vitro tube form preparations of isolated intestine of streptozotocin (STZ) diabetic rats, frequency of spontaneous intraluminal pressure waves was significantly reduced in duodenum when compared with normal controls. In order to elucidate further the diabetic intestinal disorders, we examined the frequency and amplitude of spontaneous length changes and contractile responses to acetylcholine (ACh) and substance P (sP) in isolated intestinal segments of normal and experimental diabetic rats. In comparison with normal controls, we could confirm the significantly decreased frequency of spontaneous length changes in isolated longitudinal and circular muscle preparations of diabetic duodenum (1 month after STZ injection). Furthermore, amplitude of spontaneous length changes was significantly decreased in circular muscle preparations of duodenum, jejunum, and ileum but not in colon nor in longitudinal muscle preparations. Dose-response curves revealed that both ACh and sP responses were significantly decreased in longitudinal and circular muscle preparations of diabetic duodenum, jejunum, and ileum but not in colon. Mechanisms of reduced contractility of diabetic intestinal smooth muscle in response to ACh and sP were discussed.     

IAPP免疫反应细胞在成年大鼠胃肠胰系统的分布与形态学研究

用免疫组织化学和免疫电镜双标记法研究了胰淀粉样多肽免疫反应细胞在正常大鼠胃肠胰系统的分布、定位和形态特征，并观察了ＩＡＰＰ与胰岛素在胰腺的共存。结果表明，大鼠胰腺和胃道各段均见有ＩＡＰＰ免疫反应细胞。在胰腺，ＩＡＰＰ与胰岛素共存于胰岛的Ｂ细胞内，也共存在散在于外分泌部的胰岛素免疫反应细胞内。胃肠道粘膜内ＩＡＰＰ免疫反应细胞主要存在于上皮和固有膜，它们的数量以胃和十二指肠较多，结肠较少。本研究首次发     

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.     

Antimicrobial resistance patterns of Escherichia coli through the digestive tract of veal calves

The aim of the present study was to evaluate differences in resistance patterns of Escherichia coli in different parts of the digestive tract of veal calves. Therefore, after slaughter, the lower intestinal tract of 19 calves was sampled at five locations (duodenum, jejunum, cecum, colon, and rectum), and up to three E. coli isolates per sample underwent susceptibility testing for seven antimicrobial agents (gentamicin, amoxycillin + clavulanic acid, tetracycline, trimethoprim + sulfamethoxazole, ampicillin, nalidixic acid, and enrofloxacin), using the Kirby-Bauer disk diffusion method. Multiresistance (resistance to more than two compounds) was present in 93.5% of all isolates (n = 179). For gentamicin, nalidixic acid, and enrofloxacin, the percentage of resistant E. coli isolates was significantly lower in the duodenum and jejunum than in the cecum, colon, and rectum. For ampicillin, the percentage of resistance was significantly lower in the jejunum, compared to the other segments of the intestinal tract. For the other antimicrobials tested, no significant differences in the percentage of resistant isolates throughout the intestinal tract were detected. In conclusion, resistance among enteric E. coli from veal calves can reach high levels and prevalence depends on localization of sampling. These considerations should be taken into account when further fine-tuning sampling protocols for indicator bacteria.     

Localization of vasoactive intestinal polypeptide in penile erectile tissue and in the major pelvic ganglion of the rat

Vasoactive intestinal polypeptide was localized by immunocytochemical techniques in the major pelvic ganglion and penile erectile tissue of the rat. Vasoactive intestinal polypeptide fibers were concentrated in penile crura with the density of innervation decreasing distally. The helicine arteries were very densely innervated while fewer fibers surrounded the deep artery of the penis. Intrinsic smooth muscle of the cavernous bodies received a moderate supply of vasoactive intestinal polypeptide immunoreactive fibers. Dorsal vascular structures, including the deep dorsal vein were innervated by vasoactive intestinal polypeptide fibers. Vasoactive intestinal polypeptide immunoreactive cell bodies were found in the major pelvic ganglion, concentrated on one end of the ganglion. Rectrograde studies with a dye injected into the penile crura indicated that neurons in major pelvic ganglion projected to the penis. Combined dye and immunofluorescent studies showed that all the dye-labeled neurons were immunoreactive for vasoactive intestinal polypeptide.

It is concluded that all vascular beds in the penis of the rat are innervated by vasoactive intestinal polypeptide fibers and that the extent of the innervation is related to the occurrence of smooth muscle. Neurons in the major pelvic ganglion probably are the main source of vasoactive intestinal polypeptide fibers to the penis.     

Compliance changes of the gastrointestinal tract in streptozotocin-induced diabetic rats

In order to elucidate diabetic gastrointestinal disorders, we measured the length, diameter, volume, and intraluminal pressure of the isolated segments of the duodenum, jejunum, ileum, and proximal colon during injection of Tyrode's solution into them, as well as wet weight. Wet weight of the stomach and of each intestinal segment of 3 cm length were similar between normal and diabetic preparations, except the duodenum. Wet weight of the diabetic duodenum was significantly heavier than that of normal. However, capacity of all diabetic gastrointestinal segments was significantly larger than that of normal ones, even after corrected for wet weight (ml/g wet weight). During saline injection, normal intestinal segments were more easily distended longitudinally than circumferentially. Contrarily, diabetic ones were distended more circumferentially than normal, as well as longitudinally. Pressure-volume relationships showed that pressure inside of the diabetic gastrointestinal tract increased much more moderately than that of normal one according to volume increase during saline injection. Similarly, tension inside of diabetic intestinal segments increased much more moderately than that of normal ones. Chord and slope compliance of diabetic gastrointestinal tract was generally larger than those of normal one. Histologically, there are no remarkable differences in cross-sectional area between normal and diabetic intestinal segments after usual fixation without intraluminal fixative injection. However, diabetic segments were much more remarkably dilated than normals were, when fixed after fixative injection. Greater compliance or distensibility of the diabetic gastrointestinal tract seemed to be one basic ground for dilatation, atony, larger appearance, transit delay, and motile disorders of the diabetic gastrointestinal tract.     

New clinical and experimental aspects of intestinal magnesium transport

Mg transport across various segments of the rat small and large bowel was measured in the absence of electrochemical gradients and using the voltage clamp technique. In the mucosa-to-serosa (ms) Mg flux across the duodenum, ileum, and colon a cellular part is involved, amounting to 40-70% of the total ms Mg flux measured across the short-circuited tissue. However, serosa-to-mucosa (sm) Mg flux is purely passive, suggesting that net Mg transport is largely determined by convectively driven Mg flux across the paracellular pathway. Mg is absorbed across the colon and ileum but in the duodenum paracellularly it is secreted due to an 'anomalous solvent drag effect'. Mg in the caecum decreases cellular ms Ca transport but in the other segments only passive ms Ca flux is reduced by a decrease of the paracellular permeability for Ca, or by a Mg-induced decrease in water absorption. Mg transport across all segments is insensitive to 1,25(OH)2D3. Dexamethasone abolishes cellular Ca transport but stimulates paracellular ms Mg flux in the duodenum. It is concluded that in the rat (a) Mg and Ca are transported by distinct cellular and paracellular mechanisms; (b) Mg transport is largely confined to the paracellular pathway; (c) the ileum and the colon are the major sites for the gut regulation of Mg homeostasis.     

类胰高血糖素肽—1免疫活性细胞在大鼠胃肠道的分布

目的 为了探讨类胰高血糖素肽—1(Glucagon—like peptide—1,GLP—1)在大鼠的胃肠道中的分布情况。方法 应用免疫组织化学ABC法,观察了6只Wistor大鼠胃肠道中GLP—1免疫活性细胞分布情况。结果 大鼠胃肠道中GLP—1免疫活性细胞密度最大的是回肠,其次是结肠和直肠。结论 GLP—1免疫活性细胞主要分布在小肠远端。