Les osidases digestives de l'escargot Helix aspersa: localisations et variations en fonction de l'état nutritionnel

1992 ◽  
Vol 70 (11) ◽  
pp. 2234-2241 ◽  
Author(s):  
Maryvonne Charrier ◽  
Corinne Rouland
Keyword(s):  
Salivary Glands ◽  
Digestive Tract ◽  
Digestive Gland ◽  
Bacterial Flora ◽  
Helix Aspersa ◽  
Similar Distribution ◽  
Synergistic Activity

Osidases were studied in brown garden snails, Helix aspersa Müller, fed or starved for 4 or 7 weeks. The digestive tract was divided into seven regions: oesophagus, crop, stomach, intestine, rectum, salivary glands, and digestive gland. The results revealed the presence of a large number of enzymes that attack alimentary carbohydrates. However, α-heterosides and starch were poorly hydrolysed, and amylase was not derived from saliva. Enzymatic secretions continued in snails subjected to 7 weeks of starvation and accumulated in the stomach, while these enzymes were active mainly in the oesophagus and the crop during nutrition. Several hypotheses are presented, including that the most active enzymes, mannanases and cellulases, may be secreted both by the salivary glands and by the digestive gland. A similar distribution is postulated for two oligosaccharidases, maltase and saccharase. Since a bacterial flora exists in the digestive tract, we also consider the possibility of a synergistic activity between osidases from the snail and those originating from the microflora.

scholarly journals Localization and Bioreactivity of Cysteine-Rich Secretions in the Marine Gastropod Nucella lapillus

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 276
Author(s):  
Mariaelena D’Ambrosio ◽  
Cátia Gonçalves ◽  
Mariana Calmão ◽  
Maria Rodrigues ◽  
Pedro M. Costa
Keyword(s):  
Salivary Glands ◽  
Digestive Gland ◽  
Crude Protein ◽  
Ex Vivo ◽  
Gill Tissue ◽  
Marine Biodiversity ◽  
Nucella Lapillus ◽  
Promising Target ◽  
Toxin Secretion ◽  
Molecular Damage

Marine biodiversity has been yielding promising novel bioproducts from venomous animals. Despite the auspices of conotoxins, which originated the paradigmatic painkiller Prialt, the biotechnological potential of gastropod venoms remains to be explored. Marine bioprospecting is expanding towards temperate species like the dogwhelk Nucella lapillus, which is suspected to secrete immobilizing agents through its salivary glands with a relaxing effect on the musculature of its preferential prey, Mytilus sp. This work focused on detecting, localizing, and testing the bioreactivity of cysteine-rich proteins and peptides, whose presence is a signature of animal venoms and poisons. The highest content of thiols was found in crude protein extracts from the digestive gland, which is associated with digestion, followed by the peribuccal mass, where the salivary glands are located. Conversely, the foot and siphon (which the gastropod uses for feeding) are not the main organs involved in toxin secretion. Ex vivo bioassays with Mytilus gill tissue disclosed the differential bioreactivity of crude protein extracts. Secretions from the digestive gland and peribuccal mass caused the most significant molecular damage, with evidence for the induction of apoptosis. These early findings indicate that salivary glands are a promising target for the extraction and characterization of bioactive cysteine-rich proteinaceous toxins from the species.

Experiments with P32 and I131 on Species of Helix, Arion, and Agriolimax

1952 ◽  
Vol s3-93 (22) ◽  
pp. 133-146
Author(s):  
VERA FRETTER
Keyword(s):  
Salivary Glands ◽  
Digestive Gland ◽  
Radioactive Iodine ◽  
Helix Pomatia ◽  
Relative Activity ◽  
The Body ◽  
Ionic Exchange ◽  
Digestive Cells ◽  
Metabolic Activities ◽  
Calcium Cells

If Helix aspersa, H. pomatia, Arion hortensis, and Agriolimax agrestis be fed on a diet which contains P32, autoradiographs show that the isotope is taken up by the digestive and lime cells of the digestive gland. From the formermost of it passes to the haemocoel, though some is retained for immediate metabolic activities; in the lime cells it is stored in calcium spherules. A very small amount of the tracer enters the body through the wall of the oesophagus, and more through the intestine, this site of diffusion being most pronounced directly after hibernation. The P33 in the haemocoel is dispersed to all tissues: all of them take up a little; in some it becomes concentrated. Concentrations appear in the nerve ring, the mucous and salivary glands, the odontophore and certain cells of the mantle. In the nervous system deposits are heavy around the fibres and slight in the cytoplasm of the cells; they indicate a compound, soluble in alcohol, which may be phospholipine, associated with medullated nerves. The phosphorus in mucous cells, most pronounced in the pedal and salivary glands, may be combined with the calcium which stabilizes mucus and prevents its rapid dispersal. The incorporation of isotope into the developing tooth of the radula indicates the relative activity of the basoblasts and cuspidoblasts: in early development of a tooth the basoblast secretes more actively, but as it becomes effete secretion by the cuspidoblast is accelerated. When the tooth is liberated from the latter there is no further addition to its substance. Phosphorus deposits in the mantle are in the calcium cells which secrete the shell. Here, as in the lime cells, and around certain blood-vessels, excess may be stored as calcium phosphate; reserves in the digestive gland are the largest. Amoebocytes concerned with the regeneration of the shell of Helix pomatia and H. aspersa carry the tracer element, and some of it is deposited in the shell. Also in the slug the tracer is transported by amoebocytes. Radioactive iodine in the lumen of the gut is taken up most readily by digestive cells; some enters the lime cells. Only in sparing quantities does this isotope pass from the gland to the rest of the body, and this entry is presumably associated with ionic exchange. It is not accumulated in any cell, except in the kidney whence it is excreted; it leaves the digestive cells to pass from the body with the faeces.

scholarly journals Histochemical localisation of carbonic anhydrase in the digestive tract and salivary glands of the house cricket, Acheta domesticus

2020 ◽  
Vol 6 (2) ◽  
pp. 191-198
Author(s):  
E. Thorsson ◽  
A. Jansson ◽  
M. Vaga ◽  
L. Holm
Keyword(s):  
Carbonic Anhydrase ◽  
Salivary Glands ◽  
Digestive Tract ◽  
Cell Types ◽  
Acheta Domesticus ◽  
Ph Gradient ◽  
House Cricket ◽  
Main Cell ◽  
Cellular Localisation ◽  
Luminal Ph

The house cricket (Acheta domesticus) is one of several cricket species with great potential to be farmed as a sustainable protein source. In order to succeed in large-scale cricket farming, knowledge of cricket digestion is essential. The digestive tract morphology of A. domesticus is well documented, but knowledge of the salivary glands is lacking. In the digestive tract of insects, the carbonic anhydrase (CA) enzyme family is believed to contribute to the luminal pH gradient. Presence of CA in the digestive tract of A. domesticus has been reported, but not the cellular localisation. This study examined the digestive tract of A. domesticus, including salivary glands, and the cellular localisation and activity of CA in fed or starved (48 h) males and females. Tissues were collected from third-generation offspring of wild A. domesticus captured in Sweden and the histology of the salivary glands and the cellular localisation of CA in the digestive tract of A. domesticus were determined, to our knowledge for the first time. The salivary glands resembled those of grasshoppers and locusts, and we suggest the two main cell types present to be parietal and zymogenic cells. Histochemical analysis revealed that CA activity was localised in midgut epithelium, both main cell types of salivary gland, and muscle along the entire digestive tract. These findings support the suggestion that CA contributes to digestive tract luminal pH gradient, by driving acidic secretions from the salivary glands and alkaline secretions from the midgut. Starvation resulted in significantly reduced body size and weight, but neither starvation nor sex had any effect on CA activity or localisation.

Enzymologie du tractus digestif de la modiole hydrothermale Bathymodiolus thermophilus (Mollusque Bivalve)

1992 ◽  
Vol 70 (12) ◽  
pp. 2298-2302 ◽  
Author(s):  
Marcel Le Pennec ◽  
Jean-Claude Martinez ◽  
Anne Donval ◽  
Angèle Herry ◽  
Peter Beninger
Keyword(s):  
Digestive Tract ◽  
Digestive Gland ◽  
Hydrothermal Vent ◽  
Digestive Enzyme ◽  
Nutrient Supply ◽  
Enzyme Assays ◽  
Bathymodiolus Thermophilus ◽  
Intracellular Digestion ◽  
Chemoautotrophic Bacteria ◽  
Structure And Ultrastructure

Although the structure and ultrastructure of the digestive tract of the hydrothermal vent mytilid Bathymodiolus thermophilus conform to those of other bivalves, enzymological data are lacking. To address this question, digestive enzyme assays and histoenzymological tests were performed on different regions of the digestive tract: labial palps, oesophagus, stomach, digestive gland, intestine, and rectum. Carbohydrases, mainly present in the digestive gland and the stomach, were the most active of the 33 enzymes studied. These enzymes would allow substantial digestion of particles from the immediate environment as well as those descending from the photic zone. Acid phosphatases present in all the compartments of the digestive tract indicate intracellular digestion, whereas alkaline phosphatase activity, mainly in the digestive gland and the stomach, demonstrates absorption phenomena. We conclude that, in addition to the nutrient supply furnished by chemoautotrophic bacteria in the gill bacteriocytes, the digestive tract is functional and provides at least some of the nutritive requirements of this species.

Histochemical and ultrastructural studies on the salivary glands of Helix aspersa (Mollusca)

2009 ◽  
Vol 196 (3) ◽  
pp. 343-354 ◽  
Author(s):  
F. J. Moreno ◽  
J. Pi∼nero ◽  
J. Hidalgo ◽  
P. Navas ◽  
J. Aijon AND ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Helix Aspersa ◽  
Ultrastructural Studies

ON THE ANATOMY OF GRYLLOBLATTA CAMPODEIFORMIS WALKER: 5. THE ORGANS OF DIGESTION

1949 ◽  
Vol 27d (6) ◽  
pp. 309-344 ◽  
Author(s):  
E. M. Walker
Keyword(s):  
Salivary Glands ◽  
Digestive Tract ◽  
Digestive Organs

The digestive organs of Grylloblatta resemble those of the orthopteran suborder Ensifera but differ strikingly in the cuticle and epithelium lining the proventriculus, in which there are 12 similar longitudinal divisions characterized by rows of flexible, backwardly directed lamellae, in place of the six divisions of the Ensifera armed with columns of complex sclerotized teeth. The proventricular collum is much longer than in any of the Ensifera; the two gastric caeca of the latter are represented by a single bilobed sac; the malpighian vessels are fewer than 30 and are simply arranged; and the salivary glands are very compact, appearing like a single organ.As a main conclusion to this and the previous papers of this series the following views are advanced:(1) The Grylloblattaria, although cursorial, are the nearest relatives of the Ensifera, but differ from the latter group too widely to be included within it.(2) The saltatorial habit has been independently evolved in the Ensifera and Caelifera.A summary is given of the main views on the function of the proventriculus in mandibulate insects, particularly the orthopteroid forms. The proventriculus of Grylloblatta is believed to serve as a regulatory valve and also possibly as a propulsive organ for the movement of food along the digestive tract.

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