scholarly journals How the liver contributes to stomach warming in the endothermic white sharkCarcharodon carcharias

2019 ◽  
Author(s):  
David C. Bernvi ◽  
Geremy Cliff
Keyword(s):  
Abdominal Wall ◽  
Digestive Tract ◽  
Intestinal Tract ◽  
Body Wall ◽  
Cold Water ◽  
Vascular System ◽  
Large Prey ◽  
Large Reservoir ◽  
Stomach Volume ◽  
Gastro Intestinal Tract

BackgroundWhite sharks and other lamnids are able to elevate their stomach temperature. The ability to heat large amounts of food to the recorded levels of up to 17°C above the ambient water temperature can’t be explained only by the heat generated by catabolism and the endothermic adaptions of the suprahepatic rete. This rete has two shunts that regulates the volume of blood flowing from the liver to the sinus venosus, thereby providing a temperature control mechanism for the GIT. The liver’s function in this temperature regulation is unknown. White shark stomach volume is well above 135 l in sub-adults to accommodate large prey items, including marine mammals. The simultaneous ingestion of large volumes of cold water during feeding will result in marked cooling of the stomach. Our study investigated the role of the liver in relation to warming the gastro-intestinal tract and the retention of elevated core temperatures.Materials and methodsThe liver morphology and its position relative to the gastro-intestinal tract were investigated in 13 white sharksCarcharodon carcharias. Stomach volume and the thickness of the abdominal wall were also measured to give a comparative estimate of heat insulation by white muscles.ResultsIn all white sharks examined the two liver lobes completely enveloped the entire gastrointestinal tract, with the anterio-ventral margins of the liver almost interlocking around the stomach. A large, conspicuous, flattened vascular system was only present on the inner surfaces of both liver lobes. The thickness of the ventral abdominal body wall is only 12% of that of the dorso-lateral body wall, so the potential for heat loss from the GIT via the belly region is high.ConclusionOur study builds on the findings of other researchers which revealed that the liver and digestive tract receive a major portion of their blood supply through the suprahepatic rete, which is a heat exchanger aimed at retaining metabolic heat generated by the red locomotory muscles. This heat is not only transferred to the stomach via its supply of warm blood but also via thermal conduction from the vessels on the inside of the liver, which envelopes the digestive tract and serves as a large reservoir of venous blood. The liver is rich in lipids, with insulatory properties to retain the heat which would otherwise be rapidly lost through the extremely thin ventral abdominal wall in temperate waters, where white sharks commonly occur. These findings provide insight into the hitherto unknown role played by the liver in the highly elevated stomach temperatures reported, thereby providing this endothermic top predator with enhanced rates of digestion.

Comparative aspects of water intake and its flow through the gastro-intestinal tract of kids and lambs

1987 ◽  
Vol 108 (1) ◽  
pp. 253-256 ◽  
Author(s):  
M. R. Alam ◽  
D. P. Poppi ◽  
A. R. Sykes
Keyword(s):  
Digestive Tract ◽  
Water Intake ◽  
Water Consumption ◽  
Intestinal Tract ◽  
Flow Through ◽  
Gastro Intestinal Tract

It is increasingly being recognized that water intake in goats is considerably lower than in sheep on the same feed (Gihad, 1976; Gihad, El-Bedawy & Mehrez, 1980; Alam, Poppi & Sykes, 1983). It is, however, difficult to judge the significance of this difference for water transactions in the digestive tract. This paper describes the comparative water consumption and flow in the digestive tract of kids and lambs.

The Use of Polyglycolic Acid Suture in Gastro-Intestinal Anastomosis

1972 ◽  
Vol 17 (3) ◽  
pp. 108-110 ◽  
Author(s):  
D. C. Miln ◽  
J. O'Connor ◽  
R. Dalling
Keyword(s):  
Physical Properties ◽  
Abdominal Wall ◽  
Intestinal Tract ◽  
Intestinal Anastomosis ◽  
Polyglycolic Acid ◽  
Gastro Intestinal Tract

One hundred and thirty four cases are presented in which polyglycolic acid (P.G.A.) sutures were used. In 34 cases the suture was inserted into the various layers of the abdominal wall and in 100 it was used in a variety of anastomoses involving the gastro-intestinal tract. In the light of our experience we feel that this suture is highly satisfactory in these situations, in addition to possessing physical properties which make it superior to catgut.

A Survey of the Enzymes from the Gastro-Intestinal Tract of Helix Pomatia

1958 ◽  
Vol 35 (3) ◽  
pp. 639-648
Author(s):  
FAY L. MYERS ◽  
D. H. NORTHCOTE
Keyword(s):  
Quantitative Analysis ◽  
Digestive Tract ◽  
Intestinal Tract ◽  
Helix Pomatia ◽  
Soluble Extract ◽  
Gastro Intestinal Tract

1. The digestive tract of the snail has been isolated and a soluble extract prepared from it and its contents. A quantitative analysis of the proteinases, lipases and twenty different carbohydrase activities present in this extract has been made. 2. Snail galactan was not degraded by the enzymic preparation. 3. The use of the preparation for cytological studies has been discussed.

Non Steroidal Anti-Inflammatory Drug Induced Damage on Lower Gastro-Intestinal Tract: Is There an Involvement of Microbiota?

2014 ◽  
Vol 9 (3) ◽  
pp. 196-204 ◽  
Author(s):  
Lucia Montenegro ◽  
Giuseppe Losurdo ◽  
Raffaele Licinio ◽  
Maria Zamparella ◽  
Floriana Giorgio ◽  
...  
Keyword(s):  
Intestinal Tract ◽  
Drug Induced ◽  
Inflammatory Drug ◽  
Anti Inflammatory ◽  
Gastro Intestinal Tract

scholarly journals Rehydration before Application Improves Functional Properties of Lyophilized Lactiplantibacillus plantarum HAC03

2021 ◽  
Vol 9 (5) ◽  
pp. 1013
Author(s):  
Karina Arellano-Ayala ◽  
Juhwan Lim ◽  
Subin Yeo ◽  
Jorge Enrique Vazquez Bucheli ◽  
Svetoslav Dimitrov Todorov ◽  
...  
Keyword(s):  
Intestinal Tract ◽  
Food Additives ◽  
Nitrogen Compounds ◽  
Protein Nitrogen ◽  
Bacterial Surface ◽  
Freeze Dried ◽  
Immunomodulatory Properties ◽  
Gastro Intestinal Tract ◽  
The Impact ◽  
Active Formulation

Preservation of probiotics by lyophilization is considered a method of choice for developing stable products. However, both direct consumption and reconstitution of dehydrated probiotic preparations before application “compromise” the survival and functional characteristics of the microorganisms under the stress of the upper gastro-intestinal tract. We evaluated the impact of different food additives on the viability, mucin adhesion, and zeta potential of a freeze-dried putative probiotic, Lactiplantibacillus (Lp.) plantarum HAC03. HAC03-compatible ingredients for the formulation of ten rehydration mixtures could be selected. Elevated efficacy was achieved by the B-active formulation, a mixture of non-protein nitrogen compounds, sugars, and salts. The survival of Lp. plantarum HAC03 increased by 36.36% compared rehydration with distilled water (4.92%) after passing simulated gastro-intestinal stress conditions. Cell viability determined by plate counting was confirmed by flow cytometry. B-active formulation also influenced Lp. plantarum HAC03 functionality by increasing its adherence to a Caco-2 cell-line and by changing the bacterial surface charge, measured as zeta potential.Hydrophobicity, mucin adhesion and immunomodulatory properties of Lp. plantarum HAC03 were not affected by the B-active formulation. The rehydration medium also effectively protected Lp. plantarum ATCC14917, Lp. plantarum 299v, Latilactobacillus sakei (Lt.) HAC11, Lacticaseibacillus (Lc.) paracasei 532, Enterococcus faecium 200, and Lc. rhamnosus BFE5263.

scholarly journals Analysis of the Gastro-Intestinal Tract of Marine Mammals: A Multidisciplinary Approach with a New Multi-Sieves Tool

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1824
Author(s):  
Giorgia Corazzola ◽  
Matteo Baini ◽  
Carla Grattarola ◽  
Cristina Panti ◽  
Federica Marcer ◽  
...  
Keyword(s):  
Cause Of Death ◽  
Marine Mammals ◽  
Intestinal Tract ◽  
Multidisciplinary Approach ◽  
Sample Collection ◽  
Important Data ◽  
New Device ◽  
Specific Protocol ◽  
Specific Analysis ◽  
Gastro Intestinal Tract

Organs and content of the gastro-intestinal tract (GIT) of marine mammals are relevant for a variety of investigations and provide data to researchers from different fields. Currently used protocols applied to the GIT for specific analysis limit the possibility to execute other investigations and important information could be lost. To ensure a proper sample collection and a multidisciplinary investigation of the GIT of marine mammals, a new multi-sieves tool and a specific protocol have been developed. This new device and approach allowed the simultaneous sampling of the GIT and its content for the main investigations concerned. The samples collected during these preliminary trials were suitable to perform all the different research procedures considered in this work. The obtained results show that with a few and easy procedural adjustments, a multidisciplinary sampling and evaluation of the GIT of marine mammals is possible. This will reduce the risk of losing important data aimed at understanding the cause of death of the animal, but also biology and ecology of marine mammals, and other important data for their conservation and habitats management.

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