Morphological features of the gastrointestinal tract of Garganey (Anas querquedula,Linnaeus 1758)—Oesophagus to coprodeum

The present work was aimed to study the gastrointestinal tract in Garganey from the oesophagus to coprodeum by the aid of the gross morphology, scanning electron microscopy and histology. At the level of the thoracic inlet, the oesophagus had a thick part which had numerous tortuous longitudinal folds carried transverse folds on them. Histologically, the thick part had thick epithelium and appeared more folded with more and larger glands. The mucosa of the proventriculus had mucosal folds appeared as a leaf-like with rounded tips. The openings of the proventriculus glands were projected with papillae on the epithelial surface. The gizzard lined with horizontal layer of cuticle which sent vertical parts of cuticle. The duodenal villi were pentagonal in shape with sharply pointed tips, while the jejunal villi were triangular with rounded ends, and the ileal villi were wide and pentagonal in shape with pointed tips. The mucosa of the duodenum, jejunum and ileum was thrown into villi lined by simple columnar epithelium with goblet cells with difference in the form, length, density and number. The apical points of the duodenal and ileal villi appeared pointed, while the jejunal villi had rounded ends. The jejunal villi were longer and numerous than the duodenal villi, but the ileal villi appeared with different length and less numerous. The mucosa of the caecum had numerous mucous glands which surrounded by circular crypts. The rectal mucosa had longitudinal folds and semilunar and circular crypts. The mucosa of the coprodeum had longitudinal folds surrounded by crypts.     

Histomorphology of the stomach, proventriculus and ventriculus of the red jungle fowl

The cranial chamber (proventriculus) and caudal chamber (ventriculus) of the stomach of the Red jungle fowl (Gallus gallus spadiceus) were examined by means of light microscopy. Both chambers presented folds of the tunica mucosa lined by a simple prismatic epithelium that was positive for neutral mucin. Simple tubular glands occupied the lamina propria of both chambers; in the ventriculus of older birds, they showed a coiled base. These ventricular glands were lined by simple cuboidal cells represented by the chief cells and a few large basal cells. The luminal and tubular koilin rodlets and folds of the ventriculus were positive to periodic acid Schiff (PAS) stain. The proventricular glands were situated between the inner and outer layers of the lamina muscularis mucosae. Cells lining the tubulo-alveolar units of the proventricular glands showed a dentate appearance. Vacuoles were not observed, and the cells were negative for Alcian-PAS stain. The tunica submucosa was very thin in the proventricular wall. In the ventriculus, it was not separated from the lamina propria owing to the absence of any lamina muscularis mucosae. The tunica muscularis of the proventriculus was formed by a thick inner layer of circular smooth muscle fibres and a thin outer layer of longitudinal fibres. In addition to these layers, oblique muscle fibres formed the most internal layer of the tunica muscularis in the ventriculus.     

Morphometric study of the layers of the canine small intestine at five sampling sites

The histology of the canine intestine has not been accurately defined. To establish the precise thickness of its different layers, whole wall samples of the small intestine were removed from 41 cadavers at five standardised sampling sites (duodenum, proximal jejunum, distal jejunum, proximal ileum and distal ileum). The total thickness was estimated by morphometry, as was the thickness of the mucosa, muscularis mucosae, submucosa and muscularis externa. In addition, the size of the lymphoid aggregates in the submucosa and the thickness of the circular and longitudinal layers within both the muscularis mucosae and the muscularis externa were estimated. The total intestinal thickness depended very much upon the thickness of the mucosa and submucosa. The mucosa decreased progressively from proximal to distal parts of the small intestine (47% reduction). The thickness of the submucosa, however, changed little from the duodenum to the distal jejunum, but increased significantly in the ileum; this change was positively correlated with the amount of lymphoid tissue. Sex influenced the thickness of the intestinal wall, with males displaying higher thickness values along the small intestine. Conversely, no correlation between bodyweight and intestinal thickness was found for any of the five sampling sites. This study gives absolute and relative values for the thickness of the layers of the dog intestine which might help in the diagnosis of small intestinal pathology from postmortem samples and/or endoscopic biopsies.     

秦岭细鳞鲑消化系统的形态学观察

运用大体解剖和常规组织学方法对秦岭细鳞鲑消化系统的组织形态进行了系统观察。结果表明,秦岭细鳞鲑的消化道由口咽腔、食道、胃和肠等4部分组成,除口咽腔外,管壁由内向外分为黏膜、黏膜下层、肌层和浆膜。口咽腔宽大,上颌、犁骨及腭骨等处布有细齿,黏膜衬以复层扁平上皮,间有较多的黏液细胞和少量的杯状细胞及味蕾;食管粗而短,黏膜向管腔突出形成多个纵行皱襞,上皮由复层扁平上皮逐渐向单层柱状过渡,上皮细胞间可见到数量较多的粘液细胞和杯状细胞,食管腺不发达;胃体积较大,呈“U”形,包括贲门部、胃体和幽门部,胃体部小凹及胃底腺结构明显,肌层发达;胃与肠相接处有63-65个幽门盲囊,肠道粗短而略微盘曲,黏膜上皮为单层柱状,未见明显的肠腺。以上结果显示,秦岭细鳞鲑消化道组织结构与其肉食性功能密切相关。肝小叶界限不清;双列肝细胞围绕中央静脉呈放射状走行,肝细胞个体大、呈多边形,核呈圆形或卵圆形,1-2个。胰脏大部分环绕前肠边缘、呈细长条索状,另可见分散于幽门盲囊及胃周围的弥散部分;其外分泌部为管泡状腺,腺细胞呈锥体形,胰岛结构明显。     

A light microscopic and immunocytochemical study of the gastrointestinal tract of the ostrich (Struthio camelus L.)

Although the histological features and endocrine cells of the gastro-intestinal tract of the chicken have been well studied, little is known about these features of the gut of the ostrich. The present study was undertaken to elucidate the histology and peptide-storing endocrine cells of the ostrich. As a rule the histological features of the gastro-intestinal tract of the ostrich corresponded to that of the fowl. However, certain differences were observed. The superficial proventricular glands were simple, branched tubular glands, while the deep proventricular glands were restricted to a slipper-shaped area and extended into the muscularis mucosae. The gizzard had a variably developed muscularis mucosae, a feature that seems to be unique to the ostrich. The villi of the small intestine were long and branched profusely, forming a labyrinthine surface. No Paneth cells were observed. The mucosa of the ceca and the first part of the rectum was thrown in large circular folds, forming a compressed spiral. Numerous melanocytes were seen in the submucosa and the connective tissue around the bloodvessels of the muscle layers at the tips of the ceca. A well developed subserosa was present throughout the gastro-intestinal tract. Endocrine cells immunoreactive to somatostatin, glucagon, gastrin, bombesin, neurotensin, substance P and pancreatic polypeptide were detected in the gastro-intestinal tract of the ostrich. The topographical distribution of those endocrine cells immunoreactive to glucagon, bombesin, neurotensin and substance P differed from that of the chicken. The results of this investigation inferred that at least one of the gut peptides of the ostrich (secretin) to be structurally different from its counterparts in mammal and chicken. Molecular heterogeneity of somatostatin was observed in endocrine cells situated in the deep ventricular glands of the ostrich.     

Histology and histochemistry of the pharyngeal cavity and oesophagus of the silverside Odontesthes bonariensis (Cuvier and Valenciennes)

The histology of the pharyngeal cavity and oesophagus of the freshwater 'silverside'Odontesthes bonariensis (Cuvier and Valenciennes) and the characteristics of their mucous cells were investigated. The histological characterization of its digestive wall revealed that the mucosa is thrown with longitudinal folds. The epithelium covering the folds was stratified with abundant mucous cells and gustative corpuscles, which are lacking in the oesophagus. The muscularis mucosa was absent. The submucosa presented the compactum stratum. The muscularis was organized in longitudinal and circular layers of muscular striated fibres. The serosa with a flat epithelium was located only in the oesophagus. Using histochemical procedures including methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cells contents of the pharyngeal cavity and those of the oesophagus. The mucous cells showed a weak periodic acid-Schiff (PAS) positive reaction in their content. The reactions for the differential analysis of sialic acids from GPs are feeble for periodic acid-Schiff at low temperature and low pH (PA*S) and KOH/PA*S and strong for periodic acid/borohydride/KOH/PAS (PA/Bh/KOH/PAS) and KOH/PA*/Bh/PAS revealing the scarce presence of C7 or C9 substituted and non-substituted sialic acids and the abundance of C7, C8 substituted sialic acids, O-acyl sugars and neutral sugars respectively. The results suggest that the pharyngeal cavity with the gustative corpuscles would induce the gastric secretion whereas the oesophagus is mainly involved in the transport of the food bolus to the stomach with the aid of abundant secretion of mucus. GPs secreted on the surface of the mucous cells, likely related to environmental conditions, would be involved in the lubrication, protection against abrasion and inhibition of microorganism proliferation.     

Histological and histochemical study of the proventriculus (Ventriculus glandularis) of common starling (Sturnus vulgaris)

The histological and histochemical structures of the proventriculus of starling (Sturnus vulgaris) were examined using haematoxylin and eosin and special staining, that is periodic acid schiff (PAS), Masson's trichrome, Alcian blue, Orcein and Reticulin. All three cranial, middle and caudal parts of the proventriculus were also studied. The study results showed that the wall of the proventriculus consisted of mucosal, submucosal, muscular and serosal tunics. The mucosal tunic presented folds and sulci on its luminal surface. In the first third of the proventriculus, the tunica mucosa characterized by presence of folds lined by stratified squamous epithelium and presence of simple tubular glands in the lamina propria. In the middle and caudal thirds of the proventriculus, the surface was covered by a columnar epithelium, and the branched tubular glands were extended through the lamina propria. From the base of the branched tubular glands, the deep proventricular glands were observed that were compound tubuloalveolar lobules. The surface epithelium of the tunica mucosa and the cells lining the proventricular glands showed a positive reaction to PAS and Alcian blue stainings. In addition, the epithelial cells of the tubular and branched tubular glands showed Masson's trichrome-positive reaction. The submucosal tunic was thin in the proventricular wall. The tunica muscularis was formed by a thin inner layer of longitudinal smooth muscle fibres and a thick outer layer of circular fibres. The serosa consisted of loose connective tissue, rich in blood vessels and covered by mesothelium.     

Morphological study of the oesophagus and stomach of the Gopher snake Pituophis catenifer

The gastrointestinal tract of the snake has various distinctions from mammals, birds and other reptiles. Five gopher snakes (Pituophis catenifer) were studied in relation to the gross anatomical measurements of visceral organs relative to body length as well as the histology of the oesophagus and the stomach. The oesophagus closely resembles the empty stomach upon gross examination. A small palpable thickening was observed at the junction of the oesophagus with the stomach. In both the oesophagus and the stomach, there were cellular and structural differences observed in the tunica mucosa which can be linked to the feeding habits and natural biology of the snake when compared to those of mammals. Both oesophagus and stomach were lined by simple columnar to pseudostratified columnar epithelium. There were no glands in the wall of the oesophagus. Scattered ciliated triangular cells (brush cells) were present among the columnar epithelial cells in the distal portion of the oesophagus. The stomach can be divided into three portions (proximal, middle and distal). The stomach has a small non-glandular portion with low folds. After this small non-glandular portion, glands started to appear and gradually increase in quantity. The largest quantity of glands appeared in the middle portion of the stomach with more branching folds resulting in a decrease in the lumen diameter. The tunica muscularis increased in thickness at the oesophageal and the pyloric-duodenal junctions. Positive statistical correlations were established in thickness of the tunica muscularis between proximal and distal portions of the oesophagus and the stomach.     

马冈鹅肠胚后发育的组织学观察

将72只5~110d马冈鹅(各半)按不同日龄随机分为9组,先后取十二指肠、空肠、回肠和直肠,应用常规组织学技术和Tiger细胞图像分析系统进行观测。结果表明:各部肠管管壁分粘膜、肌层和浆膜三层,无粘膜下层;绒毛既有分支,也有融合现象;肠腺主要是单管状腺,但也有分支管状腺;粘膜上皮中柱状细胞从前向后逐渐减少,而杯状细胞则相应逐渐增多;肠腺中的柱状细胞则由前向后逐渐增多,杯状细胞相应减少;肌层分内纵、中环、外纵三层,内、外两肌层厚度近似,中环肌最厚,内有明显的结缔组织间隔带分布,小肠段呈有规律的"竹节"状;粘膜皱襞不发达,少数皱襞由粘膜、内纵和中环肌层共同构成;肠壁内淋巴组织丰富,在肌层之间及肌层内均可见淋巴小结,肌层内也有神经丛和神经纤维束的断面;绒毛高度发育的绝对生长高峰期在26d以前,但绒毛直径的发育无明显的阶段性。     

The histological observations on the large intestine of the goose (Anser anser) during the pre- and post-hatching periods

The development of the cecum and colon in the goose was investigated during the period from the 15th to 28th day of the incubation and from 1 to 30 days of age after hatching by light microscopy. By day 15 of the incubation, in the cecum and colon, the lumen was surrounded by pseudostratified epithelium. The previllous ridges appeared at 15th and 17th days of the incubation in the colon and ceca, respectively. At the base of previllous ridges, the epithelium changed into a simple prismathic epithelium at 15th and 17th days of the incubation in the colon and cecum, respectively. The villi appeared at the 21st days of the incubation. The crypts and goblet cells appeared on the first day after hatching. In the pre-hatching period, the lamina muscularis mucosa was present only in the colon. The submucosa consisted of loosely aggregated connective tissue in the pre-hatching period. In the post-hatching period, it consisted of a very thin layer of connective tissue. Its presence was only obvious where the cells of the submucosal nerve plexus or occasional large blood vessels considerably increased its thickness. The nerve plexus corresponding to the Auerbach's plexus of the mammalian intestine and submucosal nerve plexus appeared by 15th days of the incubation. From the 15th to 28th day of incubation, the tunica muscularis consisted of circular smooth muscle cells in the ceca. On the 28th day of the incubation a thinner longitudinal muscle layer added to the circular muscle layer. In the colon there was an outer longitudinal and a thicker circular muscle layer.     

Detection of apoptotic cells in intestines from horses with and without gastrointestinal tract disease

OBJECTIVE: To identify apoptosis in equine intestines and determine whether apoptosis is associated with gastrointestinal tract disease or a specific tissue layer of intestine. ANIMALS: 38 horses that underwent surgery or were euthanatized for small or large intestine obstruction, strangulation, or distension and 9 control horses euthanatized for reasons other than gastrointestinal tract disease or systemic disease. PROCEDURE: Specimens were collected at surgery from intestine involved in the primary lesion and distant to the primary lesion site or at necropsy from several sites including the primary lesion site. Histologic tissue sections were stained with H&E, and apoptosis was detected by use of the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique. The number of apoptotic cells per hpf was counted in the mucosa, circular muscle, longitudinal muscle, and serosa. RESULTS: Apoptotic nuclei were seen in all layers of intestine. An increased number of apoptotic cells was found in the circular muscle of the intestine from horses with simple obstruction, compared with strangulating obstruction or healthy intestine. Intestine distant from a primary strangulating lesion had higher numbers of apoptotic cells than did intestine distant from a simple obstructive lesion or intestine taken at the site of a strangulating or simple obstructive lesion. CONCLUSIONS AND CLINICAL RELEVANCE: Intestine from horses with obstructing or strangulating lesions in the small intestine and large colon had high numbers of apoptotic cells possibly because of ischemic cell injury and subsequent inflammation. Whether substantial apoptosis affects intestinal function is not yet known.     

雌性空怀双峰驼生殖道的形态结构

应用组织学方法观察了雌性空怀双峰驼生殖道的形态结构。结果显示，双峰驼生殖道的基本结构与其他哺乳动物相似，但微细结构有差异。双峰驼输卵管粘膜皱襞极其发达，分支多而呈复杂的网状迷路。皱襞基部的迷路酷似固有膜而存在腺体，迷路网格内常见细胞团块。虽然双峰驼怀孕时胎儿位于左侧子宫角，但左、右子宫角以及子宫体的组织结构基本相同。子宫内膜无肉阜，上皮下陷于固有膜内，形成大量长而弯曲的单管状腺。子宫颈固有膜浅层分布有许多小腺体，深层分布有成群的较大腺体。这些腺体为分支管状腺，腺上皮PAS强阳性。阴道粘膜上皮为复层上皮。从输卵管到阴道，粘膜上皮主要为单层柱状上皮，由纤毛细胞和分泌细胞组成，局部可见假复层柱状纤毛上皮。纤毛细胞由前向后逐渐减少，但在子宫颈仍可见到。粘膜上皮和腺上皮内夹有许多淋巴细胞或中性粒细胞，后段局部甚至见到这些免疫细胞浸润于上皮细胞间。固有膜内分布有大量淋巴细胞、中性粒细胞、肥大细胞、浆细胞和巨噬细胞，有时出现淋巴滤泡。     

Histomorphometrical and stereological study of the oesophagus in the adult male Persian squirrel (Sciurus anomalus)

The Persian squirrel (Sciurus anomalus) is habitat in the Middle East countries and feed on pine acorns and other seeds. The present study was carried out to investigate the histological and volumetric features of the oesophagus in Persian squirrels. Five adult male Persian squirrels were included in the study. The cervical, thoracic and abdominal oesophagus of all subjects were processed routinely and sectioned in a serial manner. Then, the total volume of the oesophagus and its different layers were estimated using Cavalieri's principle. Histological assessment revealed a non‐keratinized stratified squamous epithelium lining the mucosa. No glands were seen in the lamina propria and submucosa. Lamina muscularis was present as a distinct layer of smooth muscle cells separating the lamina propria from the tunica submucosa. The tunica muscularis consisted of two distinct layers of striated muscle fibres: inner circular and outer longitudinal that was intermingled with few scattered smooth muscle fibres especially in the abdominal region. The thoracic region contained more amount of the lamina muscularis and tunica muscularis in comparison to the cervical or abdominal regions. The obtained results revealed that the histological structure of the Persian squirrel oesophagus has differences and similarities with other rodents and even with other species of squirrel. These findings would be useful to improve the knowledge in the areas of histological structure of the rodent digestive system.     

Histomorphology of the Proventriculus of three Species of Australian Passerines: Lichmera indistincta, Zosterops lateralis and Poephila guttata

Histomorphology of the proventriculi of nectarivorous, granivorous and omnivorous passerines was studied. The proventriculus consisted of mucosal, submucosal, muscularis and serosal layers. Proventricular wall was thickest in omnivore, thinnest in granivore and intermediate in nectarivore. The openings of mucosal glands had a single spiral-like fold of mucosa in the omnivorous Silvereye, 2–3 spirals in the granivorous Zebra finch and 4–5 spirals in the nectarivorous Brown honeyeater. The mucosal glands were arranged in a uniform row in the wall of the organ and opened individually via a primary duct to the lumen of the proventriculus. The surface epithelial cells of the tunica mucosa contained secretory cells and the proventricular glands contained endocrine, neck and oxynticopeptic cells. The ultrastructural features of the oxynticopeptic cells changed from the oral to the aboral portion of the gland. In the oral region, the cytoplasm presented numerous, smaller (600–900 nm) homogenously dense zymogen secretory vesicles and larger (0.8–2.3 μm) pale floccular, tubular, mucin-like secretory granules, few small mitochondria and RER while in the aboral portion of the gland, the cytoplasm presented numerous, large mitochondria with closely packed cristae, secondary lysosome and infolding of the basal and apical cell membrane. The tunica sub mucosa was thin with occasional large blood vessels. The tunica muscularis consisted of inner longitudinal, middle circular and outer longitudinal layers. The external tunica serosa contained large bundles of myelinated and unmyelinated axons that were possibly branches of the intestinal nerve. The structural adaptations of the proventriculi of these three species to their various diets are discussed.     

Histomorphometric and histochemical characteristics of the oesophagus of the greater mouse-eared Bat,Myotis myotis (Borkhausen, 1797)

The aim of this study was to examine the histomorphometric and histochemical structure of oesophagus of the wild-caught greater mouse-eared bat M. myotis. For this purpose, 10 specimens of oesophagus were collected and processed. The oesophagus wall of M. myotis is composed of four layers: tunica mucosa, tunica submucosa, tunica muscularis and tunica adventitia. The mucosa is covered by a non-keratinized stratified squamous epithelium. There were no glands in the wall of the oesophagus. Tunica muscularis is composed of two muscle layers: internal circular muscular layer and an external longitudinal muscular layer. Histochemical studies revealed that the oesophagus was AB/PAS and PAS positive indicating the presence of acidic and neutral mucosubstances. AB-PAS staining shows that glycoproteins were predominant in the all examined layers of the oesophagus. Because of the absence of oesophageal glands in M. myotis, positive reaction with AB-PAS staining may be due to secretion of salivary glands. Absence of oesophageal glands reflects the functional adaptation as high food passage rate for the insectivorous feeding habits of animals.     

Proteinase-activated receptor 2 expression in the intestinal tract of the horse

Proteinase-activated receptor 2 (PAR₂) is a G-protein-coupled receptor for trypsin and mast cell tryptase; it is highly expressed at the intestinal level with multiple functions, such as epithelial permeability and intestinal motility. Many proteases activate PAR₂ during tissue damage, suggesting a role of the inflammatory response receptors. The aim of the study was to evaluate the distribution and expression of PAR₂ in the jejunum, the ileum and the pelvic flexure, using samples collected from healthy adult horses after slaughter. Proteinase-activated receptor 2 immunoreactivity (PAR₂-IR) was observed in the enterocytes, intestinal glands, the smooth muscle of the muscularis mucosae, and the longitudinal and circular muscle layers; there were no differences in the distribution of PAR₂-IR in the different sections of the intestinal tract. The protein expression level showed that the relative amount of the PAR₂ content in the mucosa of the intestinal tract decreased from the small to the large intestine while the PAR₂ mRNA analysed showed similar values. This study provides relevant findings concerning the distribution of the PAR₂ in the intestines of healthy horses and represents the starting point for evaluating the role of the PAR₂ during strangulative intestinal disease and consequent systemic intestinal reperfusion/injury complications in horses in order to identify and employ antagonist PAR₂ molecules.     

Ultrasonographic intestinal muscularis thickening in dogs with histologically confirmed inflammatory bowel disease: 13 cases (2010–2021)

Ultrasonographic intestinal muscularis thickening has not been described as an imaging feature of canine inflammatory bowel disease. In this retrospective case series, patients were identified by searching sonographic reports for “muscularis” and/or “muscular layer.” Patients were included if small intestinal muscularis thickening was reported, and sonographic images and histopathological samples of the small intestine were available for review. Cases with small intestines nodules, masses, or complete loss of wall layering were excluded. Sonographic images were retrospectively evaluated for jejunal muscularis layer thickness, and ratios of intestinal layer measurements were performed. Histological samples were retrospectively reviewed. Thirteen dogs met inclusion criteria: all dogs had sonographic intestinal muscularis thickening relative to the submucosa (>1.0, range of 1.3–2.5), and most dogs had muscular layer thickness above normal published ranges (11/13; all 13/13 above the weight-specific mean). More than half of the patients had overall normal wall thickness (11/13) and several had normal mucosal echogenicity (6/13). Therefore, in some dogs, the only sonographic abnormality in the small intestine was muscularis thickening. No dogs had lymphadenomegaly. Endoscopic partial-thickness (n = 11, duodenum and/or ileum) or surgical full-thickness (n = 2) samples confirmed inflammatory bowel disease. Direct comparison between jejunum sonographic characteristics and histology features was limited due to both partial thickness biopsies and lack of direct comparison between anatomical locations of ultrasonographic assessment and biopsy site. However, no cases that met the inclusion criteria had normal small intestinal histology. Comparable to cats, dogs with ultrasonographic intestinal muscularis thickening may have inflammatory bowel disease, and further workup for enteropathy is indicated.     

An immunohistochemical study of S-100 protein in the intestinal tract of Chinese soft-shelled turtle, Pelodiscus sinensis

The present work describes the distribution of S-100 protein in the intestinal tract of a Chinese soft-shelled turtle specimen (Pelodiscus sinensis). S-100 protein positive cells were located in the intestinal tract, from the proximal small to distal large intestine. S-100 protein positive dendritic cells had irregular shape and were positive in both cytoplasm and nucleus. Most of them were located both lamina propria and submucosa in the small intestine, while few were found in the large intestine. S-100 protein, C-kit positive ICCs and Silver staining glial cells were predominantly observed in three locations: (1) in the interspace between the submucosa and circular muscle layer; (2) in the circular muscle layer; and (3) between the circular and longitudinal muscle layers of the intestine. Fewer were found in the large intestinal lamina propria and submucosa. Three types of positive cells (S-100 protein positive cells, C-kit positive ICCs and Silver staining glial cells) with 1–2 long or 2–3 short processes were distributed as lace-like or surrounding blood vessels in the different locations mentioned above. In the lamina propria, all the positive cells with irregular processes were connected with each other and formed a network. In the submucosa, all the positive cells were found surrounding the blood vessels.     

An immunohistochemical study of S-100 protein in the intestinal tract of Chinese soft-shelled turtle,Pelodiscus sinensis

The present work describes the distribution of S-100 protein in the intestinal tract of a Chinese soft-shelled turtle specimen (Pelodiscus sinensis). S-100 protein positive cells were located in the intestinal tract, from the proximal small to distal large intestine. S-100 protein positive dendritic cells had irregular shape and were positive in both cytoplasm and nucleus. Most of them were located both lamina propria and submucosa in the small intestine, while few were found in the large intestine. S-100 protein, C-kit positive ICCs and Silver staining glial cells were predominantly observed in three locations: (1) in the interspace between the submucosa and circular muscle layer; (2) in the circular muscle layer; and (3) between the circular and longitudinal muscle layers of the intestine. Fewer were found in the large intestinal lamina propria and submucosa. Three types of positive cells (S-100 protein positive cells, C-kit positive ICCs and Silver staining glial cells) with 1–2 long or 2–3 short processes were distributed as lace-like or surrounding blood vessels in the different locations mentioned above. In the lamina propria, all the positive cells with irregular processes were connected with each other and formed a network. In the submucosa, all the positive cells were found surrounding the blood vessels.