Gastrointestinal tract source

Fig. 1 Layers of the gastrointestinal tract (Source OpenStax College, Rice University, USA (http //coninions.wikiniedia.Org/wiki/File Layers of the GI Tract english.svg))...

The carcinogenicity of nitrosamines has created widespread concern over the safety of food products that are significant sources of nitrates and nitrites. Nitrosamines are readily formed by reaction of secondary amines with nitrites at acid pH, conditions which may occur in the gastrointestinal tract. 

The modes of action for niclosamide are interference with respiration and blockade of glucose uptake. It uncouples oxidative phosphorylation in both mammalian and taenioid mitochondria (22,23), inhibiting the anaerobic incorporation of inorganic phosphate into adenosine triphosphate (ATP). Tapeworms are very sensitive to niclosamide because they depend on the anaerobic metaboHsm of carbohydrates as their major source of energy. Niclosamide has selective toxicity for the parasites as compared with the host because Httle niclosamide is absorbed from the gastrointestinal tract. Adverse effects are uncommon, except for occasional gastrointestinal upset. 

C2H5OH, ethanol is formed by bacteria in the gastrointestinal tract in low amounts. Most of the ethanol of bacterial source is metabolized during the first liver passage yielding acetaldehyde and subsequently acetic acid. 

Parenteral Fluids. During the past ten years interest has been renewed in the total alimentation of the infant by vein (2). The motivation for this is the fact that neonates may suffer from some congenital malformation of the intestinal tract which would require surgical resection. If this is done, then one needs some outside way for alimentation, bypassing the intestine, until the intestine is able to heal and recover its normal function. This may take many weeks. A second source of motivation is the small premature infant weighing less than a kilogram, whose immature central nervous system and gastrointestinal tract make it difficult to establish nutrition by oral intake soon after birth. These also require total intravenous nutrition for a substantial period of time. 

Myo-inositol is one of the most biologically active forms of inositol. It exists in several isomeric forms, the most common being the constituent of phospholipids in biological cell membranes. It also occurs as free inositol and as inositol hexaphosphate (IP6) also known as phytate which is a major source from food. Rice bran is one of the richest sources of IP6 as well as free inositol. Inositol is considered to belong to the B-complex vitamins. It is released in the gastrointestinal tract of humans and animals by the dephosphorylation of IP6 (phytate) by the intestinal enzyme phytase. Phytase also releases intermediate products as inositol triphosphate and inositol pentaphosphate. Inositol triphosphate in cellular membrane functions as an important intra- and intercellular messenger, that merits its value as a nutritional therapy for cancer. 

The final mechanism of action of PTH involves the activation of vitamin D3 through the stimulation of la-hydroxylase in the kidney. In the gastrointestinal tract, vitamin D3 is essential for the absorption of calcium. Enhanced absorption of calcium from dietary sources serves to further increase the concentration of calcium in the blood. Many foods, in particular, dairy products, which are rich in calcium, are fortified with vitamin D. The release of PTH from the parathyroid glands is regulated by plasma calcium levels through negative feedback. A decrease in the level of calcium in the blood stimulates the secretion of PTH and an increase in the calcium level in the blood inhibits it. 

In studies with normal adult animals, orally administered radiocerium moves rapidly through the gastrointestinal tract. About 0.96 of a cerium nitrate solution administered orally to rats was excreted within 24 hours (Sagan and Lengemann, 1973). However, external irradiation of the gastrointestinal tract with a 137Cs source (800 R) delayed excretion of the radiocerium. Only about 0.85 of the administered cerium was excreted by 3 days but 0.992 was excreted by 4 days. In swine, 0.98 of an oral dose of radiocerium was excreted by 3 days (Miller et al., 1969) while in cattle, radiocerium placed in the rumen required 3.7 days for 0.9 of the dose to be excreted. Fecal excretion of the cerium still occurred after 4 days. When radiocerium was placed in the abomasum of cattle, it was almost entirely voided in 1.2 days. 

Human excretion is thought to be the principal source of estrogens and progestagens. These compounds are readily adsorbed from the gastrointestinal tract and through the skin or mucous membranes, and are metabolized in the... 

Meat and such high protein plant foods as soy are excellent sources of phosphorus as well as protein. The phosphorus in meat is readily absorbed from the gastrointestinal tract however, much of the phosphorus in plant products is in a bound form which may inhibit the absorption of calcium as well as phosphorus. This study was designed to determine the effect of different levels of calcium and phosphorus with plant protein or animal protein on bone breaking strength and calcium and phosphorus utilization of weanling mice. 

In developing countries, however, where the low quality of life, poor sanitary conditions, poor standards of food processing, storage and handling, and poor-quality drinking water obtained from contaminated sources, increase morbidity in diseases acquired via the gastrointestinal tracts. 

Histamine is synthesized in tissues by decarboxylation of amino acid L-histidine, a process catalyzed by the pyridoxalphosphate-dependent enzyme L-histidinedecarboxylase. Histamine can enter the organism with food it also can be generated by bacteria of the gastrointestinal tract. However, these sources do not create additional reserves of histamine since exogenous histamine is easily catabolized in the organism. 

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