Ultrastructure of fetal alimentary organs: stomach and spiral intestine in the southern stingray, Dasyatis americana

1996 ◽  
Vol 74 (8) ◽  
pp. 1431-1443 ◽  
Author(s):  
William C. Hamlett ◽  
John A. Musick ◽  
Allison M. Eulitt ◽  
Robert L. Jarrell ◽  
Matthew A. Kelly
Keyword(s):  
Endoplasmic Reticulum ◽  
Enteroendocrine Cells ◽  
Mucous Cells ◽  
Spiral Intestine ◽  
Gastric Glands ◽  
Spiral Valve ◽  
Apical Cytoplasm ◽  
Lysosomal System ◽  
Fetal Intestine ◽  
Oxynticopeptic Cells

In the fetal southern stingray, Dasyatis americana, both the stomach and spiral intestine function early in development to digest and absorb nutrient histotroph elaborated by uterine villi termed trophonemata. The gastric mucosa consists of a surface columnar mucous epithelium that is confluent with gastric pits or foveolae. Gastric glands are populated by oxynticopeptic and enteroendocrine cells. The surface mucous cells are pyramidal with apical microvilli. Oxynticopeptic cells are low columnar with a distinct and elaborate tubulovesicular system in the apical cytoplasm. Microvilli line the lumen of the gastric glands and cells have elaborate interdigitating lateral folds. Enteroendocrine cells are characterized by basal granules and a prominent rough endoplasmic reticulum. The fetal intestine is filled with bile-tinged viscous fluid. A core of submucosa supports spiral intestinal plicae that form the spiral valve from which villi project. The most prominent characteristic of the cells are enormous supranuclear vesicles formed by coalescence of smaller endocytotic vesicles. The apical cytoplasm has a profusion of smooth tubules, endoplasmic reticulum, and lysosomes. The large vesicles are interpreted as storage depots for continually ingested histotroph. Small vesicles may then bud off to be digested via the lysosomal system.

Uremic Gastropathy in the Dog

1979 ◽  
Vol 16 (3) ◽  
pp. 292-309 ◽  
Author(s):  
N. F. Cheville
Keyword(s):  
Endoplasmic Reticulum ◽  
Lamina Propria ◽  
Vascular Injury ◽  
Parietal Cell ◽  
Cell Function ◽  
Gastric Glands ◽  
Cell Content ◽  
Calcium Salts ◽  
Argentaffin Cell ◽  
Mucosal Lamina Propria

Stomachs of four dogs with uremia and four normal dogs were examined. Uremic stomachs represented four types of disease: atrophic, amyloidotic, ulcerative and necrotic gastropathy. Pathologic changes common to all uremic stomachs were expansion of the lamina propria, atrophy of gastric glands, and submucosal arteriopathy; lesions were limited to body and fundic zones. Lamina propria was markedly expanded by edema, mastocytosis, deposition of acidic mucosubstances, fibroplasia and mineralization. Capillaries in lamina propria had swollen endothelium and calcium salts were present extracellularly as amorphous granular laminae. Gastric glands were distorted and irregular and had fewer cells per unit of tissue. Parietal cells were swollen and had fragmentation of cytocavitary network and mitochondrial swelling with calcification. Chief cells were shrunken, agranular and atrophic with foci of glycogen and dilation of endoplasmic reticulum. Argentaffin cell content was diminished. Muscular arteries of submucosae had segmental degenerative lesions characterized by myocyte necrosis, calcification, and deposition of acidic mucosubstances and fibrin; thrombosis and obstructive arteriopathy were common. These studies suggest that uremic gastropathy is a disease of mucosal lamina propria and that lesions were due to anoxia caused by diffuse vascular injury and to altered parietal cell function.

Intracellular digestion and cellular defecation in a monogenean, Diclidophora merlangi

Parasitology ◽  
1975 ◽  
Vol 70 (3) ◽  
pp. 331-340 ◽  
Author(s):  
D. W. Halton
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Digestive Enzymes ◽  
Host Protein ◽  
Blood Proteins ◽  
Host Fish ◽  
Intracellular Digestion ◽  
Thiamine Pyrophosphatase ◽  
Lysosomal System ◽  
Pyrophosphatase Activity

The ultrastructural and cytochemical changes accompanying intracellular digestion and cellular defecation in the haematin cell of Diclidophora merlangi have been described. Blood proteins of the host-fish are sequestered by endocytosis and degraded within an interconnecting network of channels that form an integral, but changing, part of the cell. The digestive enzymes involved originate in the granular endoplasmic reticulum and are packaged in the Golgi apparatus and transferred to the channels in Golgi vesicles. The rate of haemoglobin absorption and the activity of the Golgi, as judged by vesicle counts and staining intensities for thiamine pyrophosphatase activity, are stimulated by the introduction of host protein into the gut lumen. The haematin residues of digestion are extruded periodically into the lumen by exocytosis involving membrane fusion. The process is a continuous one and, in worms starved of food, can result in the complete evacuation of pigment from the cell. It is suggested that a lysosomal system operates in the digestive cycle of the haematin cell.

The Development of Intracellular Membranes Concomitant with the Appearance of HCL Secretion in Oxyntic Cells of the Metamorphosing Bullfrog Tadpole

1969 ◽  
Vol 4 (3) ◽  
pp. 709-727
Author(s):  
GERTRUDE M. FORTE ◽  
L. LIMLOMWONGSE ◽  
J. G. FORTE
Keyword(s):  
Endoplasmic Reticulum ◽  
Apical Cell ◽  
Morphological Development ◽  
Structural Development ◽  
Gastric Glands ◽  
Cytoplasmic Matrix ◽  
Stage Of Development ◽  
Hcl Secretion ◽  
Bullfrog Tadpole

Bullfrog tadpole stomachs of various metamorphic stages were examined to determine the fine-structural development of oxyntic cells and to correlate observed morphological development with the capacity to secrete HCl. It was found that in vitro tadpole stomachs can consistently be stimulated to secrete acid by stage XXIV of metamorphosis, when tail reabsorption is nearly complete. Concomitant with the appearance of HCl secretion, identifiable oxyntic cells were found in the gastric glands. Prior to stage XXIV (stages XXI and XXII) the majority of cells present in the developing gastric glands exhibit features of cytological organization characteristic of undifferentiated cells: large nuclei, relatively scantry cytoplasm, and numerous ribosomal particles within the cytoplasmic matrix. The newly differentiated oxyntic cells of stage XXIV tadpole stomachs are recognizable by the accumulation of tubular members of the smooth-surfaced endoplasmic reticulum in the apical portion of the cells. These membranous structures appear to be formed by the Golgi complex which is extremely elaborate at this stage of development. As the animals complete metamorphosis (stage XXV) further development of the oxyntic cells occurs, especially the elaboration of the tubular components of the smooth-surfaced endoplasmic reticulum. The abundance of these membranous tubules within the apical cell regions and the pattern of their packing is similar to that observed in oxyntic cells of adult frogs. Also consistent with studies on adult frogs, structural alterations associated with HCl secretion were seen in the later stages of metamorphosis. In stages XXIV and XXV tadpole stomachs, which had been stimulated to secrete acid by addition of histamine, the apical surfaces of oxyntic cells were invested with long filamentous microvilli which projected into the glandular lumen. These observations support the hypothesis that membrane transformations play an integral role in the mechanism of HCl secretion and they implicate the morphogenesis of the smooth-surfaced endoplasmic reticulum as a basic prerequisite in the development of gastric secretory function.

scholarly journals Heterogeneity of glycoconjugates in the secretory cells of the chinchilla middle ear and eustachian tubal epithelia: a lectin-gold cytochemical study.

1991 ◽  
Vol 39 (1) ◽  
pp. 71-80 ◽  
Author(s):  
K Ueno ◽  
D J Lim
Keyword(s):  
Endoplasmic Reticulum ◽  
Middle Ear ◽  
Goblet Cells ◽  
Ultrastructural Level ◽  
Sialic Acids ◽  
Secretory Cells ◽  
Ciliated Epithelium ◽  
Mucous Cells ◽  
Cytochemical Study ◽  
Serum Type

The present study was conducted to characterize and localize the glycoconjugates in the tubotympanum (auditory or eustachian tube and middle ear cavity) of chinchilla on an ultrastructural level, using lectin-gold complexes with six different lectins: BPA, ConA, RCA-1, WGA, LFA, and SNA. A comparison of the affinity of these lectins demonstrated the heterogeneity of secretory cells. The glandular serous cells and epithelial dark granulated cells produced "serum"-type glycoprotein. The glandular mucous cells and goblet cells produced dominantly "mucin"-type glycoprotein in the light granules, but "serum"-type glycoprotein in the dark cores. The labeling of LFA and SNA showed that sialic acids existed mainly in the mucinous granules of secretory cells and ciliated epithelium glycocalyx, and in the mucous blanket. The results also suggested that the dominant linkage of sialic acids of mucin is a Neu5Ac(alpha 2-6)Gal/GalNAc sequence. Furthermore, the data obtained from ConA and BPA suggested that initial O-glycosylation of mucin took place in the cis side of the Golgi apparatus and that initial N-glycosylation of the serum occurred in the rough endoplasmic reticulum.

Nervous Control of Stomach Movements in Dogfishes and Rays

1980 ◽  
Vol 60 (1) ◽  
pp. 1-17 ◽  
Author(s):  
J. Z. Young
Keyword(s):  
Alimentary Canal ◽  
Digestive System ◽  
Dietary Habit ◽  
Large Area ◽  
Spiral Intestine ◽  
Nervous Control ◽  
Spiral Valve ◽  
Large Particles ◽  
Narrow Lumen

The organization of the alimentary canal of fishes differs greatly between species of different dietary habit, but is not well understood. The vagus and sympathetic systems are very different in elasmobranchs and teleosts, but there has been little work on the corresponding physiology and pharmacology. The digestive system of elasmobranchs has unusual features connected with the fact that the absorbtive surface is provided by the spiral intestine (Fig. 1). This is a short fat tube whose surface is greatly increased by the presence of a coiled fold, the spiral valve. This arrangement provides a large area for absorbtion, neatly packed, but it leaves only a narrow lumen, so that no large particles can pass along the spiral intestine. Presumably it is in connexion with this condition that the stomach is divided into two parts. The cardiac division is a large sac into which the prey is received whole, its wall is very glandular and much breakdown of the food proceeds there (Hogben, 1967). The pyloric division is a narrower tube, leading from the hind end of the cardiac part to the pylorus.

scholarly journals NHE8 plays important roles in gastric mucosal protection

2013 ◽  
Vol 304 (3) ◽  
pp. G257-G261 ◽  
Author(s):  
Hua Xu ◽  
Jing Li ◽  
Huacong Chen ◽  
Chunhui Wang ◽  
Fayez K. Ghishan
Keyword(s):  
Gastric Ulcer ◽  
Physiological Role ◽  
Mucosal Surface ◽  
Sodium Absorption ◽  
Bicarbonate Secretion ◽  
Mucosal Protection ◽  
Mucous Cells ◽  
Gastric Glands ◽  
Surface Ph ◽  
Gastric Mucosal Protection

Sodium/hydrogen exchanger (NHE) 8 is an apically expressed membrane protein in the intestinal epithelial cells. It plays important roles in sodium absorption and bicarbonate secretion in the intestine. Although NHE8 mRNA has been detected in the stomach, the precise location and physiological role of NHE8 in the gastric glands remain unclear. In the current study, we successfully detected the expression of NHE8 in the glandular region of the stomach by Western blotting and located NHE8 protein at the apical membrane in the surface mucous cells by a confocal microscopic method. We also identified the expression of downregulated-in-adenoma (DRA) in the surface mucous cells in the stomach. Using NHE8−/− mice, we found that NHE8 plays little or no role in basal gastric acid production, yet NHE8−/− mice have reduced gastric mucosal surface pH and higher incidence of developing gastric ulcer. DRA expression was reduced significantly in the stomach in NHE8−/− mice. The propensity for gastric ulcer, reduced mucosal surface pH, and low DRA expression suggest that NHE8 is indirectly involved in gastric bicarbonate secretion and gastric mucosal protection.

Electron microscopy of the oxynticopeptic cells of the gastric glands and the intestinal glands of the caecum of the guineapig

1992 ◽  
Vol 26 (1) ◽  
pp. 47-52 ◽  
Author(s):  
H. S. Bal ◽  
N. G. Ghoshal
Keyword(s):  
Electron Microscopy ◽  
Cell Types ◽  
Cell Type ◽  
Gastric Glands ◽  
Mature Adult ◽  
Pepsinogen Secretion ◽  
Pure Cell ◽  
Haematoxylin And Eosin Stain ◽  
Protein Secreting ◽  
Oxynticopeptic Cells

Histomorphology of the gastric and intestinal glands was investigated in 19 sexually mature, adult guineapigs by light and transmission electron microscopy. Gastric glands exhibited the cytological characteristics of oxynticopeptic cells capable of both hydrochloric acid (HCl) and pepsinogen secretion. In the literature, occurrence of oxynticopeptic cells in tbe proventriculus of the domestic fowl (Toner, 1963; Bell & Freeman, 1971) and in the gastric glands of frogs has been reported (Sedar, 1961; Patt & Patt, 1969; Forte & Forte, 1970). It has been claimed by other investigators (Herriot et al., 1938; Long, 1967) that simultaneous secretion of HCl and pepsinogen by a single, not completely differentiated 'pure' cell type, was highly effective for rapid conversion of the zymogen to active enzyme. Under the light microscope with haematoxylin and eosin stain, the protein secreting activity of gastric glands in guineapigs was masked by the HCl secreting activity, thus morphologically resembling the oxyntic cells. Therefore, different cell types, for example protein-secreting peptic cells and the acid-secreting oxyntic cells, could not be distinguished on the basis of their morphology and staining affinity. For histochemical evaluation of the sections with stains-all method, most cells in the gastric glands responded by a positive reaction to protein. Further, protein containing cells were seen in the intestinal glands of the guineapig caecum. The function of this cell type was correlated with caecotrophic food habits of this species.

THE EFFECT OF TEMPERATURE VARIATIONS AND OF CERTAIN DRUGS UPON THE INTESTINAL MOTILITY OF ELASMOBRANCH FISHES

1933 ◽  
Vol 8 (1) ◽  
pp. 145-160 ◽  
Author(s):  
J. V. V. Nicholls
Keyword(s):  
Intestinal Motility ◽  
Spontaneous Contraction ◽  
Effect Of Temperature ◽  
Spiral Intestine ◽  
Temperature Variations ◽  
Spiral Valve ◽  
Spasmodic Contraction ◽  
Elasmobranch Fishes

A rise of temperature increases the rate of the spontaneous contraction of the spiral intestine and valve, rectum and colon. At any one temperature the upper end of the spiral intestine has the same rate of contraction as the lower end, whereas the upper end of the spiral valve has a higher rate than the lower end. The rectum and colon have no rapid rhythm, but give a single spasmodic contraction every half hour or so.Adrenaline, pilocarpine and acetylcholine stimulate all the above parts, though the effect of pilocarpine on the spiral valve is very indefinite. Atropine has no effect on normal contractions, but counteracts the effect of acetylcholine and pilocarpine.

Ultrastructure and Morphometric Analysis of Interstitial Cells of Cajal in the Gastric Wall of the Bullfrog (Rana catesbeiana)

2022 ◽  
pp. 1-6
Author(s):  
Yujie Huang ◽  
Meiling Gong ◽  
Xianshu Chen ◽  
Yijie Chen ◽  
Bikai Lu ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Interstitial Cells Of Cajal ◽  
Rana Catesbeiana ◽  
Gastric Wall ◽  
Interstitial Cells ◽  
Vital Role ◽  
Gastric Glands ◽  
Tunica Muscularis ◽  
Cells Of Cajal ◽  
Oxynticopeptic Cells

Interstitial cells of Cajal (ICC) play a vital role in the gastrointestinal motility. However, information on ICC in lower vertebrates is rare. Here, ICC and ICC-like features of the gastric wall in the bullfrog (Rana catesbeiana) were observed by light microscopy and transmission electron microscopy. The lengths and distances of the ICC/ICC-like features were measured by morphometric analysis. The gastric wall contained mucosa, submucosa, tunica muscularis, and serosa. The gastric glands contained mucous cells and oxynticopeptic cells. The ICC with 1–3 processes were located among smooth muscle cells (SMC) of the tunica muscularis. Moreover, the ICC-like features were observed among oxynticopeptic cells of the mucosa. The processes of ICC established direct contacts with SMC. Also, the gap junctions were observed between the processes of ICC and nerve fiber bundles in the tunica muscularis. The multivesicular bodies, including shedding exosomes, were frequently observed between ICC and SMC. In addition, ICC-like features and their processes were observed in close proximity to oxynticopeptic cells and blood vessels. Our findings illustrated that ICC are present in the gastric tunica muscularis, and ICC-like features were in the mucosal lamina propria of the gastric wall of R. catesbeiana. These histological evidences supported the notion that ICC are implicated in gastric motility.

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