scholarly journals Morphology, histology and histochemistry of the digestive tract of the Banded tilapia, Tilapia sparrmanii (Perciformes: Cichlidae)

2020 ◽  
Vol 37 ◽  
pp. 1-14
Author(s):  
Grace E. Okuthe ◽  
Bongile Bhomela

This study described anatomical, histological and histochemical features of the mucosal layer of the digestive tract of Tilapia sparrmanii Smith, 1840, an omnivorous freshwater fish endemic to Southern Africa. This species exhibited a short thick oesophagus with long deep longitudinal folds (466.68 ± 16.91 µm), and a thick (173.50 ± 10.92 µm) muscular layer that allow the passage of large food items. The mucosa was lined with stratified secretory epithelium rich in goblet cells that secreted neutral and acid mucins. The stomach was a sac-like structure with simple tubular glands surrounded by connective tissue. The mucosa was lined with simple columnar epithelium and the lamina propria exhibited a well-developed layer of gastric glands that occupied the entire length of the cardio-fundic region. The stomach mucosa consisted of epithelial cells with intense neutral mucin secretion which protects against gastric juice. Neck cells of gastric glands synthesized neutral and acid mucins. The intestine was highly coiled and presented a complex pattern of transversal folds internally (villi). Villi length decreased progressively from the anterior to the posterior intestine (p < 0.0001). Tunica muscularis of the mid-intestine had the thinnest thickness among all parts of the intestine (p < 0.0001). Goblet cells whose numbers increased towards the rectum secreted both acid and neutral mucins. The results indicate structural similarities of T. sparrmaniiGIT with other tilapia species and will be useful for understanding the physiology of the digestive systems as well as functional components of the GIT.

2021 ◽  
Vol 49 (4) ◽  
pp. 565-575
Author(s):  
Daniela Corona-Rojas ◽  
Renato Peña ◽  
Carmen Rodríguez-Jaramillo ◽  
Dariel Tovar-Ramírez ◽  
Patricia Hinojosa-Baltazar

The histological structure, histochemical features, and enzymatic activity of the digestive tract of juvenile Pacific seahorse (Hippocampus ingens) are described to provide information during the cultivation of this species. Serial histological sections were stained with either hematoxylin-eosin, alcian blue-PAS, toluidine blue, Sudan black, Masson's trichome, and ninhydrin-Schiff to describe the general features and the presence of glycogen, mucopolysaccharides, lipids, muscle layers, and proteins, respectively. The enterocytes height and the mucosal villi height in the esophagus and intestines were measured. Additionally, the digestive enzymes trypsin, chymotrypsin, lipase, amylase, aminopeptidase, acid phosphatase, and alkaline phosphatase activities were recorded. The esophagus showed two distinctive regions, the anterior with numerous mucous cells secreting acid mucins and the posterior with longitudinal folds and no mucous cells. The intestine was differentiated into three regions. The anterior showed goblet cells secreting acid and neutral mucins, while the middle and posterior regions presented goblet cells secreting only acid mucins. The activity of aminopeptidase, chymotrypsin, and amylase showed low levels, while the trypsin and acid phosphatase activity levels were intermediate. Lipase and alkaline phosphatase showed the highest activities. The results point that juvenile H. ingens presents a digestive structure similar to other teleost species. The high levels of lipase suggest that juvenile H. ingens have high requirements for lipids during this stage.


2005 ◽  
Vol 288 (1) ◽  
pp. C46-C56 ◽  
Author(s):  
Camille Ehre ◽  
Andrea H. Rossi ◽  
Lubna H. Abdullah ◽  
Kathleen De Pestel ◽  
Sandra Hill ◽  
...  

Airway goblet cells secrete mucin onto mucosal surfaces under the regulation of an apical, phospholipase C/Gq-coupled P2Y2receptor. We tested whether cortical actin filaments negatively regulate exocytosis in goblet cells by forming a barrier between secretory granules and plasma membrane docking sites as postulated for other secretory cells. Immunostaining of human lung tissues and SPOC1 cells (an epithelial, mucin-secreting cell line) revealed an apical distribution of β- and γ-actin in ciliated and goblet cells. In goblet cells, actin appeared as a prominent subplasmalemmal sheet lying between granules and the apical membrane, and it disappeared from SPOC1 cells activated by purinergic agonist. Disruption of actin filaments with latrunculin A stimulated SPOC1 cell mucin secretion under basal and agonist-activated conditions, whereas stabilization with jasplakinolide or overexpression of β- or γ-actin conjugated to yellow fluorescent protein (YFP) inhibited secretion. Myristoylated alanine-rich C kinase substrate, a PKC-activated actin-plasma membrane tethering protein, was phosphorylated after agonist stimulation, suggesting a translocation to the cytosol. Scinderin (or adseverin), a Ca2+-activated actin filament severing and capping protein was cloned from human airway and SPOC1 cells, and synthetic peptides corresponding to its actin-binding domains inhibited mucin secretion. We conclude that actin filaments negatively regulate mucin secretion basally in airway goblet cells and are dynamically remodeled in agonist-stimulated cells to promote exocytosis.


2016 ◽  
Vol 68 (3) ◽  
pp. 641-649 ◽  
Author(s):  
Ivana Koledin ◽  
Renata Kovac ◽  
Vesna Rajkovic ◽  
Milica Matavulj

Acrylamide (AA) is an important industrial chemical worldwide. AA also forms naturally in many high-carbohydrate foods (bread, French fries, coffee, etc.) when they are heated. Since AA is ubiquitous in the human diet, and more than one-third of the calories we take in each day come from foods with detectable levels of acrylamide, the aim of this study was to determine the effect of subchronic AA treatment on colon goblet cell mucin secretion. Male Wistar rats were gavaged with AA for 5 days a week for 21 days. The animals were divided into three groups that were gavaged with different AA concentrations (0, 25, 50 mg/kg/day). Colon samples were processed for histochemical (PAS-AB, HID-AB) and immunohistochemical (anti-rat MUC2 antibody) staining to visualize mucins in the goblet cells. AA treatment showed an alteration in mucin production and secretion in that the amount of all investigated mucin types dropped. More prominent changes were detected in the upper crypt part where a decreased number of goblet cell was observed. AA treatment elicited a significant reduction in neutral mucins, while acidic mucins showed linearly decreasing trend with respect to AA doses. Also, a linear reduction of MUC2 mucins was noticed. Sulfomucins were absent in the colon lower crypt in all experimental groups, while in the upper crypt both sulfo- and sialomucins were significantly decreased. The results of our study point to changes in the synthesis, differentiation and distribution of mucins after AA treatment, which can have adverse effect on colorectal health.


2011 ◽  
Vol 83 (4) ◽  
pp. 1303-1312 ◽  
Author(s):  
Thaís Klaion ◽  
Mauricio Almeida-gomes ◽  
Luiz E. R. Tavares ◽  
Carlos F. D. Rocha ◽  
Monique Van Sluys

Proceratophrys boiei is an endemic cycloramphid anuran inhabiting the leaf litter of Atlantic rainforests in Southeastern Brazil. We analyzed the whole digestive tract of 38 individuals of Proceratophrys boiei collected in two Atlantic Rainforest areas in the state of Rio de Janeiro, Brazil, to study the diet composition and the helminth fauna associated with this species. The main food items in P. boiei's diet were Coleoptera, Orthoptera and Blattaria. Five nematode species were found: Aplectana delirae, Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp. (larval stage only) and an unidentified nematode. Overall prevalence was 71% and mean infection intensity was 7.3 ± 5.8 neatodes per individual.


Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 277-289
Author(s):  
Tohru Masui

To reveal differentiation potency of yolk-sac endoderm, this tissue from quail embryos was cultured alone or in association with digestive-tract mesenchymes of chick embryos. When yolk-sac endoderm was cultured alone in vitro, the endoderm of the area vitellina differentiated into the yolk-sac parenchyma, but the endoderm of the extraembryonic area pellucida (EEAP) failed to differentiate into yolk-sac parenchyma, and the endoderm of the area vasculosa became necrotic. When endoderm of the area vitellina was cultured in association with digestive-tract mesenchymes, all the endodermal cells developed into yolk-sac parenchymal cells after two days. Later, basophilic cells appeared among them, and differentiated into both mesenchymespecific epithelia and intestinal-type epithelium with a striated border, and villi were also formed. Goblet cells appeared in all types of recombinations. The endoderm of the EEAP cultured with digestive-tract mesenchymes gave similar results to that of the area vitellina. In contrast, endoderm of the area vasculosa, when cultured with digestive-tract mesenchymes,became necrotic. The present investigation demonstrated that the endoderms of the area vitellina and of the EEAP differ in self-differentiation potency, and that their developmental fates can be modified by the influence of digestive-tract mesenchymes. These endoderms can differentiate into the mesenchyme-specific epithelia, though they often differentiate also into the intestinal-type epithelium.


Author(s):  
Silvia M. Kreda ◽  
Lisa Jones ◽  
Lama Moussa ◽  
Leslie Fulcher ◽  
Yunxiang Zhu ◽  
...  
Keyword(s):  

2003 ◽  
Vol 285 (1) ◽  
pp. L149-L160 ◽  
Author(s):  
Lubna H. Abdullah ◽  
Jason T. Bundy ◽  
Camille Ehre ◽  
C. William Davis

SPOC1 cells, which are a mucin-secreting model of rat airway goblet cells, possess a luminal P2Y2 purinoceptor through which UTP, ATP, and ATPγS stimulate secretion with EC50 values of ∼3 μM. PMA elicits mucin secretion with high EC50 (75 nM) and saturation (300 nM) values. For the first time in airway mucin-secreting cells, the PKC isoforms expressed and activated by a secretagogue were determined using RT-PCR/restriction-enzyme mapping and Western blotting. Five isoforms were expressed: cPKCα, nPKCδ and -η, and aPKCζ and -ι/λ. PMA caused cPKCα and nPKCδ to translocate to the membrane fraction of SPOC1 cells; only nPKCδ so responded to ATPγS. Membrane-associated nPKCδ and mucin secretion increased in parallel with ATPγS concentration and yielded EC50 values of 2–3 μM and maximum values of 100 μM. Effects of PMA to increase membrane-associated cPKCα and nPKCδ saturated at 30 nM, whereas mucin secretion saturated at 300 nM, which suggests a significant PKC-independent effect of PMA on mucin secretion. A prime alternate phorbol ester-receptor candidate is the C1-domain protein MUNC13. RT-PCR revealed the expression of ubiquitous (ub)MUNC13-2 and its binding partner, DOC2-γ. Hence, P2Y2 agonists activate nPKCδ in SPOC1 cells. PMA activates cPKCα and nPKCδ at high affinity and stimulates a lower affinity PKC-independent pathway that leads to mucin secretion.


2007 ◽  
Vol 292 (1) ◽  
pp. L92-L98 ◽  
Author(s):  
Andrea H. Rossi ◽  
Wendy C. Salmon ◽  
Michael Chua ◽  
C. William Davis

Despite the general importance of Ca2+ signaling in signal transduction, and of goblet cell mucin hypersecretion in inflammatory pulmonary diseases, measurement of airway goblet cell intracellular Ca2+ (Ca[Formula: see text]) has not been reported. In this article, we describe the results of experiments measuring Ca[Formula: see text] in primary cultures of human bronchial goblet cells after stimulation with the purinergic agonist adenosine 5′- O-(3-thiotriphosphate) (ATPγS) and phorbol 12-myristate 13-acetate (PMA). Ca2+ signaling in human goblet cells after purinergic stimulation follows the classic paradigm of a Ca[Formula: see text] transient from a basal activity of 110 nM to a peak response of 260.1 ± 41.2 nM within 2 min, followed by a long superbasal plateau (155.3 ± 0.2 nM) between 10 and 15 min. The rise in Ca[Formula: see text] appears to result from a mobilization of intracellular stores, because the transient was nearly abolished by inhibition of PLC with the phosphatidylinositol-specific PLC inhibitor U-73122, and it was not affected significantly by removal of extracellular Ca2+. Loading goblet cells with BAPTA inhibited the ATPγS-induced Ca2+ transient by 86.0 ± 13.1%, relative to control. Finally, in contrast to the massive effects of high doses of PMA (300 nM) on mucin secretion from goblet cells, phorbol ester stimulated a small (27.1 ± 7% of the ATPγS control peak), brief rise in Ca[Formula: see text]. This diminutive signal likely denotes a local Ca2+ gradient, which may be associated with the mucin granule exocytotic process.


Tracheal mucin secretion has been measured from a segment of trachea, isolated in situ , in anaesthetized geese by a method that involves radioactive labelling of tracheal mucus glycoproteins (Gallagher et al. 1975). Goose tracheal mucus comes entirely from goblet cells, since the goose trachea does not contain submucosal mucous or serous glands, and this method has been used to investigate the nervous and pharmacological control of the mucin secretion from these epithelial goblet cells. The mucins secreted have been collected, fractionated, and chemically analysed. Intracellular mucin has been examined histochemically, and the results of electron microscopic observations of epithelial cells and nerves are presented. Acetylcholine increased tracheal mucin secretion, and this effect was completely blocked by atropine. Neither α- nor β-stimulant sympathomimetic amines affected tracheal mucin secretion. Stimulation of the peripheral cut ends of the descending oesophageal nerves increased tracheal mucin secretion and the majority of this response, approximately three-quarters, appeared to be cholinergic since this proportion was blocked by atropine. The mediator for the atropine-resistant part of the response is not known, but it appears not to be a β-adrenoreceptor stimulant since the response to nerve stimulation was unaffected by propranolol given at 34 μm intrasegmentally. Other possibilities are discussed. Atropine itself decreased the resting level of tracheal mucin secretion. The local anaesthetic, lignocaine, increased tracheal mucin secretion, while at the same time blocking the responses to acetylcholine and descending oesophageal nerve stimulation. The implications of this are discussed. The electrophoretic, gel filtration and ion-exchange properties of goose tracheal mucins showed that they represented high molecular mass, negatively charged glycoproteins which could be labelled biosynthetically with [ 35 S]sulphate, [ 3 H]- and [ 14 C]glucose. These mucins could be stained with Alcian blue or periodic acid Schiff reagent. The carbohydrate composition was unusual for an epithelial glycoprotein in that fucose was absent and mannose was present in small quantities. The monosaccharides present in larger quantity were galactose, N -acetylglucosamine, N -acetylgalactosamine and sialic acid. Histochemical analysis of tissue sections of gosling tracheas demonstrated that nearly all of the glycoprotein in epithelial goblet cells contained both sialic acid and sulphate residues. Sialated mucin was present also, but to a lesser extent, and many cells contained a mixture of sialated and sulphated mucins. The adult goose trachea had a high proportion of sialated glycoprotein. Electron microscopy showed a range of epithelial cell types and intra-epithelial nerves also. Many of the nerves had neurosecretory vesicles suggestive of motor function and some were near to goblet cells.


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