• Anatomy and Cell Biology
• /
• v.56 no.1
• /
• pp.25-31
• /
• 2023

Johannes Nathanael Lieberkühn was a prodigious anatomist whose meticulous experiments and precise detailing helped in comprehending the microscopic anatomy of digestive system during early part of eighteenth century. Notably, his inventions in the field of microscopy aptly complemented his quest for anatomical knowledge at microscopic level. He designed a reflector (Lieberkühn reflector) which enhanced the amount of focussed light leading to bright illumination of tissue specimen. He invented the solar microscope which provided excellent resolution of minute anatomical details. Lieberkühn discovered the digestive juice secreting tubular glands (glands of Lieberkühn) present at the base of intestinal villi producing epithelial invaginations (crypts of Lieberkühn). He also described the intricate juxtaposition of blood vessels in relation to a single intestinal villi. Moreover, through empirically designed experimental set up, Lieberkühn was able to demonstrate the flow of lymph from intestinal villi to collecting lymphatic vessels. Also, his grandiose collection of laboratory specimens involving vascular anatomy are a testimony of his untiring efforts in academia. His contributions were seminal in comprehending the anatomy of digestive system and paved the way for future revelations. His work unveiled the enormous scope of microanatomy in medical science and catalysed the advent of histological staining methods a century later.

• Animal cells and systems
• /
• v.4 no.4
• /
• pp.375-379
• /
• 2000

The appearance of some gastrointestinal endocrine cells in the Meckel's diverticulum (MD) of the bean goose, Anser fabalis Latham was observed using specific antisera against serotonin, gastrin, cholecystokinin (CCK)-8, glucagon, secretin, somatostatin and human pancreatic polypeptide (HPP) with the peroxidase antiperoxidase (PAP) method. Among these specific antisera, serotonin-, gastrin-, CCK-8-, somatostatin- and HPP-immunoreactive cells were demonstrated in this study. Serotonin-, gastrin- and somatostatin-immunoreactive cells were detected at moderate frequency and CCK-8- and HPP-immunoreactive cells was rare and low frequencies, respectively. These immunoreactive cells were located in the superficial epithelium, intestinal crvpt and intestinal glands with spherical or spindle shaped cells having long cytoplasmic processes (open typed-cell). Mucosal layer of MD was composed of simple columnar epithelium and numerous intestinal glands. In addition, numerous lymphatic tissues were also demonstrated. In conclusion, histological profiles of MD were similar to any parts of the large intestine, especially the cecum, but the appearance, distribution and relative frequency of gastrointestinal endocrine cells were similar to those of upper parts of the small intestine. Although the exact digestive functions were unknown, the finding that the appearance, distribution and relative frequency of gastrointestinal endocrine cells in MD is similar to small intestine may be considered as distinct evidence that this organ may have some digestive functions.

• Parasites, Hosts and Diseases
• /
• v.27 no.2
• /
• pp.109-118
• /
• 1989

Production of circulating specific antibodies to the lung fluke (Paragenimus westermani) by its host is well known and used in various kinds of immunodiagnostic methods, However, it has not been well documented which compartments (or structures) of the lung fluke are most responsible for the production of specific antibodies. The present immunohistochemical study was undertaken to demonstrate the antigenicity of each body compartment of p. westermani such as suckers, tegument, spines, vitelline glands, intestine, reproductive organs(male and female), and eggs. Indiret immunoperoxidase(IP) stain technique was applied, using formalin-fked, paraffin- embedded lung tissues of P westermani-infected cats sectioned in 4 Um thickness as the antigen and cat antisera (11~20 weeks of infection) as the primary antibody. Peroxidase-conjugated goat anti-cat IgG was used as the secondary antibody and diaminobensidine(DAB) as the coloring agent. Strong yellow or yellowish brown staining was regarded positive. The primary and secondary antibody dilutions were made at 1 : 500~1 : 2, 000 and 1 : 200~1 : 500 respectively, and IP stain was repeated 10 times for each dilution. A consistent result obtained was that the intestinal epithelial border, intestinal content, vitelline glands, and eggs scattered around the worm capsule showed strong positive staining, while uterine eggs and some parenchymal portions showed weak positive reaction. On the other hand, the suckers, tegument, spines, subtegumental cells, cytoplasm of intestinal epithelial cells, male reproductive organs, and ovary revealed negative staining. The body compartments showing higher antigenicity were, in the decreasing order, the intestinal epithelial border, intestinal content, eggs in the worm capsule, vitelline glands, uterine eggs, and parenchymatous portions. The intestinal epithelial border and luminal contents revealed positive staining even at a few concentration of 1 : 4, 000 primary antibody(secondary ab., 1 : 200) whereas the parenchymatous portion showed positive reaction only at higher concentrations than 1'500 (secondary ab., 1 : 200). The results suggest that the specific antibody responses of the host to p. westermani occur most strongly upon the excretes from the intestinal epithelium of the worm and e99s Produced around the worm capsule,

• Korean Journal of Veterinary Research
• /
• v.42 no.4
• /
• pp.443-449
• /
• 2002

The morphological studies on the rectal development in the 60-, 90- and 120-day-old fetuses and neonates of Korean native goats were investigated by light microscopy and scanning electron microscopy. The rectal wall appeared to be differentiated into the epithelium, lamina propria, tunica muscularis and serosa in 60-day-old fetus. The rectal epithelia were stratified in some areas and simple columnar in others at 60- and 90-day-old fetuses but was only observed simple columnar epithelium at 120-day-old fetus. The goblet cells and the intestinal glands appeared in the rectal mucosa at 90-day-old fetus and gradually increase in number during gestation period. The rectal villi appeared at 60-day-old fetus and increased in length and width until 90-day-old fetus but the villi appeared to be shorter and degenerated after 120-day-old fetus. Only the rudiment trace of the villi remained at birth. The tunica muscularis of the rectum were continuously developed during gestation period. The inner circular and outer longitudinal muscle layers of rectum were observed in the 120-day-old fetuses. Under scanning electron microsoopy, the rectal villi appeared at 60-day-old fetus. The pentagonal/hexagonal microridges and numerous microvilli were observed on the luminal surface of rectal wall. Low and thumb-like rectal villi were developed at 90-day-old fetus. The rectal villi became degenerated after 120-day-old fetus. Only the rudiment of villi was remained at birth. Many circular folds were well developed. Opening portions of intestinal glands appeared like slot.

• Korean Journal of Veterinary Research
• /
• v.37 no.1
• /
• pp.9-13
• /
• 1997

The gastrointestinal endocrine cells of the African clawed toad, Xenopus laevis have been investigated immunohistochemically using the avidin-biotin method. Seven antisera were tested and three endocrine cell types immunoreacted with antisera to neurotensin, GRP and substance P. A moderate number of neurotensin-immunoreactive cells were weakly reacted in the small intestine. GRP-immunoreactive cells were mainly situated among the upper portion in the fundic glands, and the basal portion in the pyloric glands. These cells were oval and round in shape. On the other hand, in the intestine they were thin spindly cells with the epithelium. Substance P-immunoreactive cells were observed in among intestinal epithelium. However, no secretin-, motilin-, M-Enk- and PYY-immunoreactive cells were found in the GIT of the African clawed toads.

• Korean Journal of Veterinary Research
• /
• v.25 no.1
• /
• pp.1-5
• /
• 1985

The morphological development of the small intestinal tissues of the Korean native goat were observed by light microscopy. Samples were taken from a 60-, 90-, 120-day-old fetus, a newborn goat and a 30-day-old goat. The results were summarized as follows; 1. In the small intestine of 60-day-old fetus, the apexes and sides of villi were covered with a simple columnar epithelium, and intervilous areas and mucosal ridges were still covered with stratified epithelium of two to six cell layers. Mesenchymal tissues formed lamina propria, circular muscle layer and serosa. The numbers of villi per cross section of the small intestine (NVPCS) were 10 to 18. 2. In 90-day-old fetus, intervillous areas and mucosal ridges of the organ were covered with simple columnar epithelium. Goblet cells in epithelium and outer longitudinal muscle layer often appeared. NVPCS were 35 to 60 and Brunner's glands were appeared. 3. In 120-day-old fetus, Brunner's glands of the duodenum and circular connection of outer longitudinal muscle layer were formed, NVPCS were 50 to 87. 4. In newborn goat, Peyer's patches were fully formed and NVPCS were 50 to 87. 5. In 30-day goat, the small intestine was fully matured and NVPCS were 81 to 102.

• Korean Journal of Ichthyology
• /
• v.17 no.4
• /
• pp.241-247
• /
• 2005

To observe the respiratory system in relation to the air-breathing organ in Iksookimia longicorpa, micro-anatomical investigation was performed on the epidermis and on intestinal tract fragments. The epidermis was distinguished by two types of skin glands, a small mucous cell and a large club cell. The mucous cell was acid sulfomucins (some sialomucins), but the club cell did not give any histochemical tests for mucosubstances. The presence of a well defined lymphatic system with small lymphocytes was established in the stratum germinativum layer of the epidermis. A large number of blood capillaries run very close to each other just below the basement membrane. The straight intestinal tract is divided into an intestine and rectum, which consisted of a mucosa (epithelial layer), lamina propria-submucosa, muscularis, and serosa. The intestine and rectum have shorter mucosal folds and a thinner wall. The majority of the epithelial mucous cells contain acid sulfomucines. Based on the above results, I. longicorpa adapts to poor dissolved oxygen conditions by using an additional respiratory system using air through the epidermis, not the intestines.

• Applied Microscopy
• /
• v.18 no.2
• /
• pp.59-76
• /
• 1988

In order to know the distribution, relative frequencies, types and morphology, endocrine cells in the intestinal tract of the hedgehog(Erinaceus koreanus) were studied by light microscopy, immunohistochemistry and electron microscopy. The results obtained are summarized as follows: 1. Two kinds of endocrine cells were demonstrated with two specific staining methods. Argyrophil cells(reactive cells for Grimelius method) were found most frequently in the intestinal region, and were infrequent in the rectum, whereas argentaffin cells (reactive cells for Masson-Hamperl method) were found most frequently in the rectum and in the other legions were infrequent. These reacting cells were mainly found in the intestinal glands, whereas a small number in the mucosa. 2. Twelve kinds of endocrine cells, gastrin(Gas)-, somatostatin (Som)-, serotonin(5-HT)-, glucagon(Glu)-, bovine pancreatic polypeptide(Bpp)-, cholecystokinin(Cck)-, secretin(Sec)-, motilin(Mot)-, glicentin(Gli)-, gastric inhibitor polypeptide(GIp)-, substance P(Sp)-, and neurotensin(Neu)-immunoreactive cells, were identified by immunohistochemical method. Gas-, Som-, 5-HT-, Glu-, Cck-, Sec-, Mot-, Gli-, Sp-, and Neu-reactive cells were observed in the duodenum, and among these Gas- and 5-HT-reactive cells were moderately found while the others were infrequent. In the jejunoileum Gas-, Som-, 5-HT-, Glu-, Cck-, Mot-, Gli-, GIp-, SP-, and Neu-reactive cells were found, and among these 5-HT- and GIp-reactive cells were moderately found while the others were infrequent. In the colon Sec-reactive cell was not detected. 5-HT-reactive cells were found most frequently and the others were infrequent in this region. 5-HT-, Bpp-, GIi- and Neu-reactive cells were found in the rectum. Among these 5-HT-reactive cells were found most frequently. 3. Electron microscopically, five types of endocrine cells, EC, ECL, D, G, A-like cell, were identified in the intestinal region. EC and ECL cells in the duodenum, EC, D and G cells in the jejuno-ileum, EC and A-like cells in the colon and EC cell in the rectum were observed respectively.

• Animal cells and systems
• /
• v.4 no.1
• /
• pp.95-100
• /
• 2000

The regional distribution and relative frequencies of endocrine cells were studied immunogistochemically (PAP methods) in the alimentary tract of the tree frog, Hyla areorea japonica, using specific antisera against serotonin, somatostatin, bovine Sp-1/chromogranin (BCG), cholecystokinin (CCK)-8, vasoactive intestinal polypeptide (VIP), gastrin, bombesin, secretin and pancreatic polypeptide (PP). Six kinds of endocrine cells were identified in this study, These immunoreactive cells were located in the gastric glands of stomach regions and in the basal portion of the epithelium of the intestinal tract or esophagus with variable frequencies. They were spherical or spindle-shaped. Serotonin-immunoreactive cells were observed in the whole alimentary tract including the esophagus. Somatostatin-immunoreactive cells were also detected throughout the alimentary tract except the rectum. CCK-8-immunoreactive cells were observed from the pylorus to ileum. Vip-immunoreactive cells were restricted to the rectum. Bombesin-immunoreactive cells were restricted to the fundic gastric regions and gastrin-immunoreactive cells were restricted to the pylorus. However, no BCG-, secretin and PP-immunoreactive cells were demonstrated in this study. In conclusion, the regional distribution and relative frequency of the endocrine cells in the alimentary tract of the tree frog were similar to other anuran species, but some differences which may be caused by feeding habits and species specification were also observed.

• Journal of Veterinary Science
• /
• v.24 no.3
• /
• pp.23.1-23.16
• /
• 2023

Background: Irritable bowel syndrome (IBS) is a functional bowel disorder (FBD). Objectives: To assess the therapeutic effects of paeoniflorin (PF) on IBS in rats. Method: Sixty male Sprague-Dawley rats were randomly divided into normal, model, positive drug, low-dose PF, medium-dose PF and high-dose PF groups (n = 10). After gavage for 2 consecutive weeks, the effect of PF on abdominal pain symptoms was assessed based on the abdominal withdrawal reflex (AWR) score, fecal water content and pathological changes in colon tissues. D-lactate, interleukin-1β (IL-1β), transforming growth factor-β (TGF-β) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay, and phosphorylated nuclear factor kappa B (p-NF-κB) p65 was detected by Western blotting. The abundance and diversity changes of intestinal flora were explored using 16S ribosomal RNA sequencing. Result: In PF groups, the mucosal morphology of colon tissues was intact, and the glands were arranged neatly and structured clearly, without obvious inflammatory cell infiltration. Compared with the model group, PF groups had significantly elevated pain threshold, and mRNA and protein levels of zonula occludens-1 (ZO-1) and occludin, decreased AWR score at 20 mmHg pressure, fecal water content, mRNA levels of IL-1β, TGF-β, and TNF-α, protein level of p-NF-κB p65 and level of serum D-lactate, and reduced levels of serum IL-1β, TGF-β, and TNF-α (p < 0.05, p < 0.01). PF groups had higher abundance of Lactobacillus, Akkermansia, Alistipes, and Bacteroides, but lower abundance of Desulfovibrio, Parasutterella, and Enterococcus than those of the model group. Conclusions: PF exerts therapeutic effects on IBS in rats probably by regulating the intestinal flora, and then up-regulating the expressions of ZO-1 and occludin in colon tissue while down-regulating the levels of IL-1β, TGF-β, TNF-α, D-lactate and p-NF-κB p65.