大鼠胃、胰CGRP阳性细胞的免疫组织化学观察

用免疫组织化学ABC法观察了大鼠胃,胰CGRP的分布。结果显示;（1）在大鼠胃内有大量的CGRP阳性神经纤维存在。未见CGRP阳性神经元。（2）大鼠胃窦部可见到少量CGRP阳性细胞：（3）在大鼠胰岛内有两种CGRP阳性内分泌细胞存在。     

牛蛙胃肠胰系统内分泌细胞的免疫组织化学鉴定与定位

应用过氧化物酶标记的链霉卵白素(S-P)免疫组织化学方法对牛蛙(Rana catesbeiana)胃肠胰系统5种内分泌细胞进行了鉴定与定位.在消化道中检测到了5-羟色胺(5-HT)、生长抑素(SS)、胃泌素(Gas)和胰高血糖素(Glu)细胞.5-HT细胞主要分布于胃幽门部和空肠,食道中偶见.SS细胞主要分布于胃,幽门部较密集,小肠各段少量,直肠和食道偶见.Gas细胞主要分布于小肠各段,胃和直肠中偶见,食道中未检测到.Glu细胞主要分布于胃和直肠,小肠各段偶见,食道中未检测到.在胰腺中检测出了5-HT、SS、Gas、Glu和胰多肽(PP)细胞.SS、Glu和PP细胞数量较多,成簇分布于胰岛中,5-HT和Gas细胞少量,散在分布于胰腺腺泡之间.胃腺部和胰腺内分泌细胞多呈圆形、椭圆形或形态不规则,有的可见明显胞突伸向邻近细胞,胃肠道上皮中的内分泌细胞多呈梭形、楔形或锥形,有的可见明显胞突伸向消化腔.与其它两栖动物相比,牛蛙胃肠胰系统内分泌细胞的存在与分布有一些共性,也存在着种间差异.     

虎斑颈槽蛇消化道5-羟色胺免疫活性内分泌细胞的分布与形态学观察

用免疫组织化学ABC(avidin-biotin-peroxidase complex)法,对虎斑颈槽蛇Rhabdophis tigrinus 5-HT免疫反应阳性内分泌细胞的分布及形态学进行了观察.结果 表明,5-HT阳性细胞从食管到直肠的消化道各段均有分布.细胞密度分布呈"N"型,胃体最高,胃幽门部和胃贲门部次之,空肠最少.5-HT阳性细胞的形态多样,其中贲门和胃以圆形或椭圆形为主,肠道(除直肠)则以锥形为主;广泛分布于上皮基部、上皮细胞之间、腺泡上皮及腺泡之间,有时可见于固有膜内.     

胎儿胃、小肠内分泌细胞分布及形态学观察

目的探讨人胃肠道内分泌细胞的分布.方法采用银浸染色方法,对10例4～6月胎儿的胃、小肠内分泌细胞行光学显微镜观察.结果胃、小肠中的内分泌细胞(嗜银细胞)形态多种多样,分布于胃、小肠绒毛上皮、小肠腺及十二指肠腺.在小肠固有膜结缔组织中也有散在的嗜银细胞.该细胞主要存在于小肠,胃部较少,其中以十二指肠最多,空肠、回肠顺次递减,而十二指肠乳头又明显高于十二指肠其他部位,在这些部位有时可见该细胞抵达腺腔,并有颗粒释放于腺腔内.结论人胎儿胃肠道含有内分泌细胞,尤其是小肠及其十二指肠乳头部.     

Bax、TGF-β和Ghrelin在饥饿后长耳鸮胃及小肠中的免疫组织化学

应用免疫组织化学方法检测了Bax蛋白、TGF-β(TGF-β2、TGF-β3)和Ghrelin在饥饿后长耳鸮(Asio otus)胃及小肠中的表达,利用体视学方法对其表达强度进行半定量分析。结果表明,胃及小肠呈Bax、TGF-β2、TGF-β3和Ghrelin免疫反应阳性。Bax免疫反应阳性物质主要分布在胃黏膜、肠黏膜、肠腺的单层柱状上皮细胞,腺胃深腺单层立方上皮细胞及胃黏膜固有层;TGF-β2、TGF-β3免疫反应阳性物质主要分布在胃黏膜、肠黏膜及肠腺的单层柱状上皮细胞,腺胃深腺单层立方上皮细胞及肠黏膜固有层;Ghrelin免疫反应阳性细胞分布在腺胃深腺,十二指肠、空肠、回肠的黏膜、肠腺的单层柱状上皮细胞及黏膜固有层。Bax蛋白阳性表达部位的面密度值在腺胃有最大值,从腺胃到十二指肠面密度值下降,十二指肠到回肠逐渐上升;TGF-β2和TGF-β3阳性表达部位的面密度值在十二指肠达到峰值,TGF-β2从十二指肠到回肠阳性表达部位的面密度值呈递减趋势,TGF-β3从腺胃到十二指肠面密度值逐渐增大,之后下降,到回肠回升;Ghrelin阳性表达部位的面密度值从腺胃到回肠逐渐减小。Bax、TGF-β2、TGF-β3及Ghrelin在饥饿后长耳鸮胃和小肠各段均有不同程度的表达,它们可能参与长耳鸮胃肠功能的调节。     

武夷湍蛙胃肠道内分泌细胞的免疫组织化学定位

用免疫组织化学S-P法,应用七种特异性胃肠激素抗血清对武夷湍蛙胃肠道7个部位内分泌细胞的局部分布、分布密度及形态学特征进行了研究。结果显示：在武夷湍蛙胃肠道中鉴别出四种内分泌细胞,即：5-羟色胺、生长抑素、胃泌素和高血糖素免疫反应细胞。P-物质、胰岛素和胰多肽免疫反应细胞未见。5．羟色胺免疫反应细胞是胃肠道中最主要的内分泌细胞类型,其在胃肠道各段均有分布,但在各段分布密度不同。生长抑制素免疫反应细胞分布于贲门至十二指肠的胃肠道各段。胃泌素免疫反应细胞局限分布于幽门和十二指肠部位。高血糖素免疫反应细胞仅在胃幽门部位有分布。在武夷湍蛙胃肠道内具有最多种类型内分泌细胞分布的部位是幽门,同时胃肠道内各种内分泌细胞在此部位也显示出最高的分布密度。武夷湍蛙胃肠道内分泌细胞形态多样：圆形、椭圆形、纺锤形、梭形、锥形和不规则形。胃部多数内分泌细胞分布于胃腺中,肠道中多数细胞则分布于上皮细胞间,少数分布于固有膜。本研究显示武夷湍蛙与其他两栖动物胃肠道内分泌细胞在分布模式上存在一定共同特征并具其独特性,以上结果提示其与武夷湍蛙消化生理学相关,和其胃肠道的调节特点相关。     

Ghrelin在成年中国黄羽鹌鹑消化道中的定位

为探讨Ghrelin免疫反应阳性细胞在成年中国黄羽鹌鹑(Coturnix japonica)消化道的分布规律及形态学特点。应用免疫组织化学SABC法对成年中国黄羽鹌鹑消化道各段Ghrelin阳性细胞进行定位和形态学研究;利用SPSS 17.0软件,对所得数据进行单因素Dunnett多重比较分析。结果显示,Ghrelin阳性细胞在成年中国黄羽鹌鹑腺胃、十二指肠、空肠、回肠和盲肠均有分布,其中在腺胃分布密度最高,为30.70±6.50,盲肠最低,为1.70±1.56,分布密度从腺胃至盲肠呈逐渐降低的趋势。Ghrelin阳性细胞主要分布于腺胃腺叶细胞、肠道黏膜上皮细胞、肠腺上皮细胞和肠固有层之间,细胞形态多为球形、长柱状和三角形。上述结果说明,Ghrelin阳性细胞在成年中国黄羽鹌鹑消化道分布广泛,根据其细胞形态推测中国黄羽鹌鹑消化道Ghrelin阳性细胞可能具有内分泌和外分泌功能。     

功能性ghrelin受体在内脏迷走和脊髓传入神经通路中的表达

本文在mRNA和蛋白水平观察了功能性ghrelin受体(growth hormone secretagogue receptor type la,GHS-Rla)在大鼠内脏迷走及脊髓传入神经通路中的表达.结果显示:(1)GHS-Rla免疫反应阳性神经元及GHS-Rla mRNA分布于背根神经节(dorsal root ganglion,DRG)及结状神经节(nodose ganglion,NG).(2)应用免疫双标技术观察到DRG和NG中都有一些GHS-Rla免疫反应阳性神经元,同时降钙素基因相关肽(calcitonin gene-related peptide,CGRP)染色呈阳性,显示GHS-Rla和CGRP共存于同一神经元,表明内脏传入神经元存在许多亚核群.(3)应用荧光金(fluorogold)标记的神经逆行追踪技术对从胃投射到DRG和NG的神经元进行免疫组织化学染色,观察到一些表达CGRP的GHS-Rla免疫反应阳性神经元也被荧光金染色.上述实验结果证实了GHS-Rla在迷走神经和脊髓传入神经元中的表达,提示ghrelin参与了胃.脑轴的调节.     

花鲈消化道内分泌细胞的鉴别和定位

应用免疫组织化学Elivision二步法 ,用 5 羟色胺 (5 HT)、生长抑素 (SST)、胃泌素 (Gas)、胰高血糖素 (Glu)、胰多肽 (PP)等 5种抗哺乳动物血清对花鲈 (Lateolabraxjaponicus)消化道内分泌细胞 ,进行免疫组织化学定位的研究。结果表明 :5 HT和SST细胞分布于食管、胃贲门部、胃体部和胃幽门部 ,而肠道各段均未检出。Gas细胞分布于胃幽门部和前肠、中肠 ;食管、胃贲门部、胃体部和后肠未检出。Glu细胞分布于前肠和中肠 ,其余各段均未检出。PP细胞在消化道各段均未检出。本文将对花鲈消化道内分泌细胞的分布密度、分布型及形态进行描述和讨论。     

大鼠小肠神经激肽A免疫反应（NKA－Ⅰ）物质分布特征的研究

本实验采用免疫细胞化学ＰＡＰ法,将切片与铺片技术相结合,全面研究了Ｗｉｓｔａｒ大鼠（ｎ＝２０）小肠神经激肽Ａ免疫（ＮＫＡ－Ｉ）阳性物质的分布特征。结果提示：ＮＫＡ－Ｉ神经元单个或多个散在分布于粘膜下和肌间的神经节内,粘膜下神经节处多见。ＮＫＡ－Ｉ神经纤维广泛分布于小肠各段的各层结构中。在小肠粘膜上皮和腺上皮中可见散在分布的ＮＫＡ－Ｉ强阳性细胞,推测为ＮＫＡ－Ｉ内分泌细胞。本文还对ＮＫＡ－Ｉ的形态学特点及生理功能进行了讨论。     

Neurohormonal peptides, serotonin, and nitric oxide synthase in the enteric nervous system and endocrine cells of the gastrointestinal tract of neotenic and thyroid hormone-treated axolotls (Ambystoma mexicanum)

Immunoreactivity against vasoactive intestinal polypeptide (VIP), neurotensin (NT), substance P (SP), calcitonin gene-related peptide (CGRP), gastrin/cholecystokinin (GAS/CCK), somatostatin (SOM), serotonin (SER), and nitric oxide synthase (NOS) was investigated in the gastrointestinal tract of the urodele Ambystoma mexicanum, the axolotl, by the use of immunohistochemical techniques. The study also compares the distribution patterns and frequencies of the neurohormones, and NOS in neotenic and thyroxine-treated (metamorphosed) individuals. GAS/CCK, SP, NT, SOM, and SER immunoreactivities occurred in endocrine mucosal cells and VIP, SP, CGRP, NTSER, SER, and NOS immunoreactivities in the enteric nervous system. The GAS/CCK-immunoreactive (-IR) cells were restricted to the upper small intestine. NT-IR and SP-IR endocrine cells were found in the entire gastrointestinal tract and were most prominent in the distal large intestine. The density of the SOM-IR cells decreased from the stomach toward the large intestine. SER-IR endocrine cells were found throughout the gastrointestinal tract, with particularly high densities in the stomach and distal large intestine. The VIP-IR enteric nerve fibers were the most prominent ones, present in all layers of the entire gastrointestinal tract, and supplied the smooth muscle and the vasculature. The SER-IR fibers exhibited similar distribution patterns but were less numerous. Very few NT-IR but many SP-IR fibers were found in the muscle and submucosal layers. The NT-IR fibers mainly supplied blood vessels, while the SP-IR fibers were also in contact with the smooth muscle. In the muscle and submucosal layers, CGRP-IR fibers were associated to the vasculature; CGRP immunoreactivity occurred also in a minority of SP-IR fibers. NOS-IR nerve fibers were in contact with submucosal arteries but were the least frequent . After metamorphosis provoked by exogenous thyroxine, the number of SOM-IR endocrine cells in the stomach mucosa was increased as well as the density of VIP-IR, SER-IR, and SP-IR nerve fibers in the gastrointestinal tract. It is proposed that the observed increases may reflect refinements of the neurohormonal system after metamorphosis.     

Neuroendocrine system of the digestive tract in Rhamdia quelen juvenile: an immunohistochemical study

In this work, an immunohistochemical study was performed to determine the distribution and relative frequencies of some neuromodulators of the digestive tract of silver catfish (Rhamdia quelen). The digestive tract of silver catfish was divided into six portions; the oesophagus, stomach, intestine (ascendant, descendant and convoluted segments), and rectum. Immunohistochemical method using a pool of specific antisera against-gastrin, -cholecystokinin-8, -leu-enkephalin, -neuropeptide Y, -calcitonin gene-related peptide (CGRP), and -vasoactive intestinal peptide (VIP) was employed. Immunoreactivity to all antisera was identified in neuroendocrine cells (NECs) localized in the gut epithelium, although no reaction was observed in the oesophagus or stomach. The morphology of NECs immunopositive to each antibody was similar. They were slender in shape, with basally located nucleus, and their main axis perpendicular to the basement membrane. The number of NECs immunoreactive to all antisera was higher in the ascendant and descendant intestine, exhibiting a decreasing trend toward distal segments of the gut. In addition, immunoreactivity to CGRP and VIP was observed in the myenteric plexus and nerve fibers distributed in the mucosal, submucosal and muscular layers. The higher number of immunopositive NECs in the ascendant and descendant intestine may indicate the primary role of these segments in the control of food intake by means of orexigenic and anorexigenic peripheral signals.     

Substance P, neurokinin A and calcitonin gene-related peptide during development of the rat gastrointestinal tract.

Substance P, neurokinin A and calcitonin gene-related peptide (CGRP) were determined in the stomach and small intestine of rats during late foetal development and up to 35 days postnatal life. Concentrations of substance P in stomach and intestine increased from 14 gestational days to 3 days postpartum, and declined thereafter. Concentrations of neurokinin A in stomach declined from 14 days gestation over the period 3-35 postnatal days. In the intestine, concentrations of neurokinin A increased steadily from 14 days gestation to 21-35 postnatal days. Concentrations of CGRP in stomach and intestine declined from 14 days gestation to 7 postnatal days. Thereafter, concentrations of CGRP increased in both stomach and intestine. Total contents of each of the three peptides increased progressively with gestational and postnatal age in parallel with increasing stomach and intestinal weights. The results demonstrate different patterns of change in the concentrations of substance P, neurokinin A and CGRP during the dynamic phases of growth and maturation of the gastrointestinal tract in the foetal and postnatal rat.     

Ultrastructure of the gastrointestinal epithelium in the marmoset (Callithrix jacchus)

The epithelium of the stomach and intestine of one and three days old as well as adult marmosets was investigated using transmission electron microscopy and was compared with already existing data of man and the laboratory rodents, rat, mouse and guinea-pig. On postnatal day (PD) 1, the enterocytes possessed an inframicrovillous membrane system and giant lysosomes which were absent in adult marmosets whereas the surface and glandular epithelial cells of the stomach showed all structures which were also typical for adult animals. Enterocytes rich in fat and glycogen were only present on PD 1. In the large intestine the vacuolated cells were more frequently seen on PD 1 and 3 than in adult marmosets. The endocrine cells of newborn animals corresponded to those in the gastric and intestinal epithelium of mature animals, occurred everywhere in the lower digestive tract and could be subdivided at least into EC, ECL, D and L and EG cells respectively; a further subdivision was not possible by conventional transmission electron microscopy. Compared with rats, mice and guinea-pigs mostly used for developmental studies of the digestive tract, marmoset monkeys differed especially from the gastrointestinal epithelium of rats and mice but also from guinea-pigs. By contrast comparisons with the human situation are difficult due to the lack of representative electron microscopic findings on the gastrointestinal epithelium. If one considers the close phylogenic relationship between marmosets and man, the marmoset data should be transferable to the human situation rather than the findings obtained for rats, mice and guinea-pigs. In the epithelium of the adult gastrointestinal tract clear-out ultrastructural differences could not be found between these species.     

Calcitonin gene-related peptide-like immunoreactivity in the human small intestine.

Calcitonin-gene-related-peptide (CGRP)-like immunoreactivity was localized in nerve fibres, neuronal somata and in mucosal endocrine cells of the human small intestine. Immunoreactive enteric neurons were more numerous in the submucous plexuses than in the myenteric plexus. Morphologically, they predominantly had the appearance of type II neurons. The majority of the CGRP-like immunoreactive nerve fibres ran within the ganglionic nerve plexuses. Only a small proportion could be observed in the lamina propria, the lamina muscularis mucosae, or the circular and longitudinal outer smooth muscle layer. These findings suggest that within the wall of the human small intestine neuronal CGRP of either extrinsic or intrinsic origin exerts its effect chiefly on other enteric neurons, and might be indirectly involved in the regulatory functions of the human small intestine.     

Distribution of peptide-containing neurons and endocrine cells in the rabbit gastrointestinal tract,with particular reference to the mucosa

Summary The distribution patterns of peptide-containing neurons and endocrine cells were mapped in sections of oesophagus, stomach, small intestine and large intestine of the rabbit, by use of standard immunohistochemical techniques. Whole mounts of separated layers of ileum were similarly examined. Antibodies raised against vasoactive intestinal peptide (VIP), substance P (SP), somatostatin (SOM), neuropeptide Y (NPY), enkephalins (ENK) and gastrin-releasing peptide (GRP) were used, and for each of these antisera distinct populations of immunoreactive (IR) nerve fibres were observed. Endocrine cells were labelled by the SP, SOM or NPY antisera in some regions.VIP-IR nerve fibres were common in each layer throughout the gastrointestinal tract. With the exception of the oesophagus, GRP-IR nerve fibres also occurred in each layer of the gastrointestinal tract; they formed a particularly rich network in the mucosa of the stomach and small intestine. Fewer nerve fibres containing NPY-IR or SOM-IR were seen in all areas. SOM-IR nerve fibres were very scarce in the circular and longitudinal muscle layers of each area and were absent from the gastric mucosa. The SP-IR innervation of the external musculature and ganglionated plexuses in most regions was rather extensive, whereas the mucosa was only very sparsely innervated. ENK-IR nerve fibres were extremely rare or absent from the mucosa of all areas, although immunoreactive nerve fibres were found in other layers.These studies illustrate the differences in distribution patterns of peptide-containing nerve fibres and endocrine cells along the gastrointestinal tract of the rabbit and also show that there are some marked differences in these patterns, in comparison with other mammalian species.     

Calcitonin gene-related peptide neurons innervating the canine digestive system.

The pattern of nerve cells and fibers containing calcitonin gene-related peptide immunoreactivity (CGRP-IR) was investigated in the canine digestive tract by means of immunohistochemistry. CGRP-IR nerve fibers innervate all the layers of the gut, including the vasculature, with different densities depending on the region. CGRP-IR processes are sparse in the esophagus and stomach, where they are mostly confined to the enteric plexuses and vasculature. CGRP-IR fibers are quite abundant in the small and large intestine, where they form dense arborizations in the mucosa, and are numerous in the muscularis mucosae, deep muscular plexus and circular muscle. The myenteric and submucous plexuses of the intestine contain dense networks of CGRP-IR fibers and numerous CGRP-IR ganglion cells. On the other hand, in the enteric ganglia of the esophagus and stomach, in the intrapancreatic ganglia and in the ganglionated plexus of the gallbladder, CGRP-IR is restricted to non-varicose processes. A moderate density of CGRP-IR fibers supplies the endocrine and exocrine pancreas, and the fibromuscular layer and lamina propria of the gallbladder. The density of CGRP innervation in different regions can be summarized as follows: intestine > pancreas and gallbladder > or = antrum > cardia > gastric corpus and distal esophagus. CGRP- and tachykinin (TK)-IRs are colocalized in a substantial population of fibers, particularly those distributed to the mucosa, muscularis mucosae and vasculature, whereas there was no evidence of colocalization in intrinsic ganglion cells. The present results suggest that (1) the CGRP innervation of the dog digestive system includes an intrinsic and an extrinsic component, and (2) CGRP- and TK-IRs are co-expressed in extrinsic nerve fibers. These findings extend previous observations in rats and guinea pigs and provide insights into the sites of action of CGRP in the digestive system of the dog, which has served as a model for CGRP functional studies.     

Localization of calcitonin gene-related peptide and islet amyloid polypeptide in the rat and mouse pancreas

Summary It was previously demonstrated that the two chemically related peptides calcitonin gene-related peptide (CGRP) and islet amyloid polypeptide (IAPP) both occur in the pancreas. We have now examined the cellular localization of CGRP and IAPP in the rat and the mouse pancreas. We found, in both the rat and the mouse pancreas, CGRP-immunoreactive nerve fibers throughout the parenchyma, including the islets, with particular association with blood vessels. CGRP-immunoreactive nerve fibers were regularly seen within the islets. In contrast, no IAPP-immunoreactive nerve fibers were demonstrated in this location. Furthermore, in rat islets, CGRP immunoreactivity was demonstrated in peripherally located cells, constituting a major subpopulation of the somatostatin cells. Such cells were lacking in the mouse islets. IAPP-like immunoreactivity was demonstrated in rat and mouse islet insulin cells, and, in the rat, also in a few non-insulin cells in the islet periphery. These cells seemed to be identical with somatostatin/CGRP-immunoreactive elements. In summary, the study shows (1) that CGRP, but not IAPP, is a pancreati neuropeptide both in the mouse and the rat; (2) that a subpopulation of rat somatostatin cells contain CGRP; (3) that mouse islet endocrine cells do not contain CGRP; (4) that insulin cells in both the rat and the mouse contain IAPP; and (5) that in the rat, a non-insulin cell population apparently composed of somatostatin cells stores immunoreactive IAPP. We conclude that CGRP is a pancreatic neuropeptide and IAPP is an islet endocrine peptide in both the rat and the mouse, whereas CGRP is an islet endocrine peptide in the rat.     

Dynamics of absorption of yellow fluorescent protein in intestine and reabsorption in kidney in rat postnatal ontogenesis

In experiments of the 5, 12 and 25-day old rat pups and adult rats in has been shown that after administration of yellow fluorescent protein (YFP) into stomach, its partial absorption in the non-degraded state in the small intestine takes place, with subsequent transport to kidney with blood flow and accumulation in cells of the proximal nephron segment. With age of rats, intensity of the intestinal YFP absorption decrease; the YFP accumulation in the kidney is more active in rats of the younger age groups than in adult animals. No accumulation of YFP in liver was revealed. The obtained data indicate an intensive absorption of YFP in the non-hydrolyzed form in the rat pup small intestine in early postnatal ontogenesis and an important role of kidney in protein metabolism and in proteolysis of exogenous proteins.