Metabolic Generation of Ammonia and Amino Acids in the Intestinal Wall and the Influence of Neomycin and Lactulose

2015 ◽  
pp. 147-153
Author(s):  
P. B. Soeters ◽  
P. A. M. van Leeuwen ◽  
M. A. Janssen ◽  
J. E. G. de Boer ◽  
H. M. Goossens ◽  
...  
Keyword(s):  
Amino Acids ◽  
Intestinal Wall

scholarly journals Protein digestion in the intestine of sheep

1974 ◽  
Vol 31 (2) ◽  
pp. 125-142 ◽  
Author(s):  
D. Ben-Ghedalia ◽  
H. Tagari ◽  
A. Bondi ◽  
A. Tadmor
Keyword(s):  
Amino Acids ◽  
Dry Matter ◽  
Intestinal Tract ◽  
Essential Amino Acids ◽  
Intestinal Wall ◽  
Simultaneous Increase ◽  
Total N ◽  
Ruminal Degradation ◽  
Protein Amino Acids ◽  
The Common

1. The rate of flow of digesta along the intestinal tract, and particularly the changes occurring in proteins during their passage through the intestine were determined in six rams; each animal was fistulated with three cannulas which involved six different sites of the intestine. Cr2O3 was used as a marker substance to measure the rate of flow of the digesta.2. In the sections of the intestine from 1 to 15 m posterior to the pylorus the amounts of water, dry matter and total nitrogen decreased gradually as a result of their absorption through the intestinal wall. The region of the intestine situated at a distance of 7–15 m from the pylorus was more active with respect to the absorption of N, whereas water and dry matter were adsorbed to a greater extent in the region from 1 to 7 m from the pylorus.3. The only part of the intestine in which substantial increases of water, dry matter and total N were found was the section immediately distal to the pylorus, and these increases were caused by the inflow of bile, and pancreatic and duodenal juices. The net increase found beyond the entry of the common bile duct was 2.7 g protein N and 2.0 g non-protein N (NPN)/24 h.4. The activities of trypsin, chymotrypsin and carboxypeptidase A and the ratio α-NH2 NPN: protein N increased from the pylorus up to a distance of 7 m and decreased again from this point to a distance of 15 m from the pylorus.5. In the sections of the intestine between 1 and 3 and between 3 and 7 m distant from the pylorus the extent of proteolysis exceeded considerably that of absorption of amino acids through the intestinal wall. This was concluded from the decrease in the rate of flow of protein amino acids (by 31% between 1 and 3 m distant from the pylorus and by 34% between 3 and 7 m) and the simultaneous increase in non-protein amino acids (by 20% in the region between 1 and 3 m) or no change in non-protein amino acids (between 3 and 7 m).6. The relatively greater decrease in non-protein amino acids (by 57%) compared with that of protein amino acids (by 41%) occurring in the section 7 to 15 m distant from the pylorus showed that this is an area of most intensive absorption of amino acids.7. In the lower section of the intestine, from 15 to 25 m distant from the pylorus, the total amount of amino acids showed almost no change; probably a net effect of loss and gain of amino acids mainly due to microbial activities. Increases in the dehydrogenase activity suggested enhancement of bacterial activity in this lower region of the intestine.8. The supply of essential amino acids to the tissues of sheep is improved, compared with the amino acid composition of the diet, as the result of ruminal biosynthesis of essential amino acids and ruminal degradation of non-essential amino acids and preferential absorption of essential amino acids through the intestinal wall, particularly in the section of most intensive absorption, 7–15 m distant from the pylorus.

Evidence for Active Transport of the Dipeptide Carnosine (β-Alanyl-l-Histidine) by Hamster Jejunum in Vitro

1974 ◽  
Vol 46 (6) ◽  
pp. 693-705 ◽  
Author(s):  
D. M. Matthews ◽  
Jill M. Addison ◽  
D. Burston
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Active Transport ◽  
Amino Acid Mixture ◽  
Intestinal Wall ◽  
Free Form ◽  
Acid Mixture ◽  
Total Uptake ◽  
Hydrolysis Of

1. The characteristics of intestinal transport and hydrolysis of carnosine (β-alanyl-l-histidine) have been studied in rings of everted hamster jejunum in vitro. 2. During incubation with carnosine, large amounts of intact peptide appeared in the intestinal wall, accompanied by small amounts of the constituent amino acids in the free form. Although there was some extracellular hydrolysis, the free amino acids appearing in the intestinal wall were almost entirely derived from intracellular hydrolysis of the peptide. Incubation in l-alanyl-l-histidine resulted in uptake of the constituent amino acids in the free form without appearance of intact peptide in the intestinal wall. 3. Total uptake of β-alanine (both peptide-bound and free) and total uptake of histidine were greater from a low concentration (1 μmol/ml) of carnosine than uptake of these amino acids from the equivalent amino acid mixture. At a high concentration of carnosine (20 μmol/ml), total uptake of β-alanine was greater from the peptide than from the equivalent amino acid mixture but total uptake of histidine was less. At this concentration, total uptake of β-alanine plus total uptake of histidine from the peptide was approximately the same as from the amino acid mixture. 4. Uptake of carnosine by jejunal rings was the result of a saturable process (Kt 9·4 μmol/ml, Vmax. 2·7 μmol g−1 initial wet wt. min−1). Intact carnosine was concentrated in the intestinal wall, the concentration ratio between intracellular fluid and incubation medium being up to 3·4/1. Uptake of carnosine was reduced by anoxia, metabolic inhibitors and replacement of medium Na+. Na+-dependent active transport was shown to be involved in uptake of carnosine by hamster jejunum in vitro.

CELIAC DISEASE AND WHEAT SENSITIVITY

PEDIATRICS ◽  
1960 ◽  
Vol 25 (1) ◽  
pp. 127-134
Author(s):  
H. A. Weijers ◽  
J. H. van de Kamer
Keyword(s):  
Amino Acids ◽  
Celiac Disease ◽  
Inborn Error ◽  
Wheat Gluten ◽  
Intestinal Wall ◽  
Inborn Error Of Metabolism ◽  
Harmful Substance ◽  
Wheat Sensitivity ◽  
Enzymatic Defect

Celiac disease is considered "an inborn error of metabolism," which becomes mainly manifest after the consumption of wheat (rye, barley, oats). Wheat gluten, especially its gliadin fraction, is shown to be the harmful substance. The cause of the action of gliadin is sought for in the glutamine-containing peptides, which, due to an enzymatic defect in the cells of the intestinal wall, would not be split normally into amino acids but would get into the blood, thus exerting an abnormal influence on the metabolism. The abnormal elevation of the gliadinloading curves is probably based on the presence of these peptides in the blood.

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Methionine-Specific Staining of Collagen

1982 ◽  
Vol 40 ◽  
pp. 294-295
Author(s):  
E.M. Kuhn ◽  
K.D. Marenus ◽  
M. Beer
Keyword(s):  
Amino Acids ◽  
Collagen Fibers ◽  
Type Iii Collagen ◽  
Type I ◽  
Electron Microscopic ◽  
Good Correspondence ◽  
Specific Staining ◽  
Type Iii ◽  
Different Types ◽  
Sulfur Containing

Fibers composed of different types of collagen cannot be differentiated by conventional electron microscopic stains. We are developing staining procedures aimed at identifying collagen fibers of different types.Pt(Gly-L-Met)Cl binds specifically to sulfur-containing amino acids. Different collagens have methionine (met) residues at somewhat different positions. A good correspondence has been reported between known met positions and Pt(GLM) bands in rat Type I SLS (collagen aggregates in which molecules lie adjacent to each other in exact register). We have confirmed this relationship in Type III collagen SLS (Fig. 1).

Prevalence of the pit and antipit in the genus Glycine

1987 ◽  
Vol 45 ◽  
pp. 986-987
Author(s):  
R. W. Yaklich ◽  
E. L. Vigil ◽  
W. P. Wergin
Keyword(s):  
Amino Acids ◽  
Endoplasmic Reticulum ◽  
Glycine Max ◽  
Seed Coat ◽  
Cell Types ◽  
Abaxial Surface ◽  
Legume Seed ◽  
Initial Report ◽  
Cone Cells ◽  
Glycine Max L

The legume seed coat is the site of sucrose unloading and the metabolism of imported ureides and synthesis of amino acids for the developing embryo. The cell types directly responsible for these functions in the seed coat are not known. We recently described a convex layer of tissue on the inside surface of the soybean (Glycine max L. Merr.) seed coat that was termed “antipit” because it was in direct opposition to the concave pit on the abaxial surface of the cotyledon. Cone cells of the antipit contained numerous hypertrophied Golgi apparatus and laminated rough endoplasmic reticulum common to actively secreting cells. The initial report by Dzikowski (1936) described the morphology of the pit and antipit in G. max and found these structures in only 68 of the 169 seed accessions examined.

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

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