In Vitro Measurement of Amino-Acid Uptake by the Human Small Intestine

Pharmacology ◽  
1964 ◽  
Vol 10 (3) ◽  
pp. 157-163 ◽  
Author(s):  
J.W.L. Robinson ◽  
F. Taminelli ◽  
J.P. Felber ◽  
P. Magnenat
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Human Small Intestine

scholarly journals Growth Hormone Enhances Amino Acid Uptake by the Human Small Intestine

1994 ◽  
Vol 219 (6) ◽  
pp. 715-724 ◽  
Author(s):  
Yoshifumi Inoue ◽  
Edward M. Copeland ◽  
Wiley W. Souba
Keyword(s):  
Growth Hormone ◽  
Small Intestine ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Human Small Intestine

Accumulation of L-phenylalanine by segments of small intestine

1961 ◽  
Vol 200 (3) ◽  
pp. 505-507 ◽  
Author(s):  
A. H. Samiy ◽  
Richard P. Spencer
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Time Course ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Outward Diffusion ◽  
Initial Event ◽  
Equilibrium Data ◽  
Site Dependence

Segments of hamster small intestine accumulate l-phenylalanine from an in vitro solution without degradation of the amino acid. Uptake by the segments equilibrates in about 20 minutes, while transport of the amino acid across intestinal sacs requires nearly 1 hour. This suggests that the initial event preceding transintestinal transport is cellular uptake of l-phenylalanine. Concentration of the amino acid in the wall of intestinal sacs during l-phenylalanine transport was equal to or greater than that in the serosal fluid. Hence it is possible that intramural accumulation is the active process and outward diffusion from wall to serosa is the passive event. Dependence of segmental uptake of l-phenylalanine on external concentration, and its increased magnitude in midintestinal segments, resembles the process occurring in intestinal sacs. On the basis of the time course of events, concentration within the wall, and concentration and site dependence, it is proposed that intestinal uptake of l-phenylalanine is the initial and essential event in its transport. For l-phenylalanine uptake, the KM calculated from initial rate data was identical to that found from equilibrium data. Usefulness of intestinal segment uptake in determining initial rates and other parameters is pointed out.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

The mechanisms of amino acid uptake byBrugia pahangi in vitro

1983 ◽  
Vol 69 (2) ◽  
pp. 247-253 ◽  
Author(s):  
R. E. Howells ◽  
A. M. Mendis ◽  
P. G. Bray
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals Rationally Design of a Proline Transporter Inhibitor with Anti-Trypanosoma Cruzi Activity

2019 ◽  
Author(s):  
Lucia Fargnoli ◽  
Esteban A. Panozzo-Zénere ◽  
Lucas Pagura ◽  
María Julia Barisón ◽  
Julia A. Cricco ◽  
...  
Keyword(s):  
Amino Acid ◽  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Variable Region ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Cell Infection ◽  
Atp Production ◽  
First Case

L-Proline is an important amino acid for the pathogenic protists belonging to <i>Trypanosoma</i> and <i>Leishmania </i>genera. In <i>Trypanosoma cruzi</i>, the etiological agent of Chagas disease, this amino acid is involved in fundamental biological processes such as ATP production, differentiation of the insect and intracellular stages, the host cell infection and the resistance to a variety of stresses, including nutritional and osmotic as well as oxidative imbalance. In this study, we explore the L-Proline uptake as a chemotherapeutic target for <i>T. cruzi</i>. For this, we propose a novel rational to design inhibitors containing this amino acid as a recognizable motif. This rational consists of conjugating the amino acid (proline in this case) to a linker and a variable region able to block the transporter. We obtained a series of sixteen 1,2,3-triazolyl-proline derivatives through alkylation and copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry) for <i>in vitro</i> screening against <i>T. cruzi </i>epimastigotes, trypanocidal activity and proline uptake. We successfully obtained inhibitors that are able to interfere with the amino acid uptake, which validated the first example of a rationally designed chemotherapeutic agent targeting a metabolite's transport. Additionally, we designed and prepared fluorescent analogues of the inhibitors that were successfully taken up by <i>T. cruzi</i>, allowing following up their intracellular fate. In conclusion, we successfully designed and produced a series of metabolite uptake inhibitors. This is one of few examples of rationally designed amino acid transporter inhibitor, being the first case where the strategy is applied on the development of chemotherapy against Chagas disease. This unprecedented development is remarkable having in mind that only a small percent of the metabolite transporters has been studied at the structural and/or molecular level.

THE METABOLISM OF ANIMAL TISSUES CULTIVATED IN VITRO: II. AMINO ACID METABOLISM OF CHICK EMBRYONIC KIDNEY, CHICK EMBRYONIC LIVER, AND MONKEY KIDNEY CORTEX CULTURES

1958 ◽  
Vol 36 (1) ◽  
pp. 171-184 ◽  
Author(s):  
Arthur E. Pasieka ◽  
Helen J. Morton ◽  
Joseph F. Morgan
Keyword(s):  
Tissue Culture ◽  
Amino Acid ◽  
Culture Medium ◽  
Synthetic Medium ◽  
Amino Acid Uptake ◽  
Monkey Kidney ◽  
Kidney Cortex ◽  
Acid Uptake ◽  
Embryonic Liver

Freshly-explanted chick embryonic kidney, chick embryonic liver, and trypsinized monkey kidney cortex cells have been cultivated in vitro in completely synthetic medium M 150. The amino acid changes in the nutrient medium during cultivation of these tissues have been studied by paper chromatography. A characteristic pattern of amino acid uptake and accumulation in the used culture medium has been demonstrated with each type of tissue culture. It has also been shown that, while the amino acid changes in the medium are different with each type of tissue culture, all cultures examined removed adenine from the medium and liberated small amounts of material thought to be hypoxanthine.

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