The application of an oral zinc tolerance test to assess zinc absorption from three different dietary sources in the dog

1995 ◽  
Vol 1995 ◽  
pp. 108-108
Author(s):  
J.A. Lowe ◽  
J. Wiseman
Keyword(s):  
Amino Acids ◽  
Hair Growth ◽  
Tolerance Test ◽  
Zinc Absorption ◽  
Zinc Tolerance ◽  
Maintenance Requirement ◽  
Metabolic Functions ◽  
Pet Owners

Zinc (Zn) is a key nutrient for dogs, playing an important role in many metabolic functions. It has been estimated that 91% of the minimum maintenance requirement for Zn is needed to support hair growth. Coat condition is perceived as being important by pet owners and is thus of fundamental concern when evaluating the adequacy of a diet for dogs.Zn absorption has been shown to vary as a function of the amount and source of the Zn in the diet and as a function of the presence of elevated calcium and / or phytate levels in the diet.It has been suggested that when dietary Zn is supplied in the form of a chelate with amino acids, rather than from inorganic sources, a greater proportion of Zn is absorbed an is thus available to the animal. Further, the undesirable effects that dietary antagonists, such as calcium, exert on Zn absorption may be negated

Does the oral zinc tolerance test measure zinc absorption?

1985 ◽  
Vol 41 (1) ◽  
pp. 37-42 ◽  
Author(s):  
L S Valberg ◽  
P R Flanagan ◽  
J Brennan ◽  
M J Chamberlain
Keyword(s):  
Tolerance Test ◽  
Zinc Absorption ◽  
Zinc Tolerance ◽  
Test Measure

Use of zinc tolerance test and 24-hour urinary zinc content to assess oral zinc absorption.

1996 ◽  
Vol 15 (1) ◽  
pp. 79-83 ◽  
Author(s):  
L M Henderson ◽  
G J Brewer ◽  
J B Dressman ◽  
S Z Swidan ◽  
D J DuRoss ◽  
...  
Keyword(s):  
Zinc Content ◽  
Tolerance Test ◽  
Zinc Absorption ◽  
Zinc Tolerance

The assessment of zinc status by the zinc tolerance test in various groups of patients

1982 ◽  
Vol 15 (5) ◽  
pp. 257-260 ◽  
Author(s):  
Ifor D. Capel ◽  
Edgar P. Spencer ◽  
Anita E. Daivies ◽  
Harry N. Levitt
Keyword(s):  
Tolerance Test ◽  
Zinc Status ◽  
Zinc Tolerance

Amino acid modulation of in vivo intestinal zinc absorption in freshwater rainbow trout

2002 ◽  
Vol 205 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Chris N. Glover ◽  
Christer Hogstrand
Keyword(s):  
Amino Acids ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Zinc Ion ◽  
Zinc Uptake ◽  
Intestinal Lumen ◽  
Zinc Absorption ◽  
Zinc Accumulation ◽  
Rainbow Trout Oncorhynchus Mykiss

SUMMARY The composition of the intestinal lumen is likely to have considerable influence upon the absorption, and consequently the nutrition and/or toxicity, of ingested zinc in aquatic environments, where zinc is both a nutrient and a toxicant of importance. The effects of amino acids upon intestinal zinc uptake in freshwater rainbow trout (Oncorhynchus mykiss) were studied using an in vivo perfusion technique. The presence of histidine, cysteine and taurine had distinct modifying actions upon quantitative and qualitative zinc absorption, compared to perfusion of zinc alone. Alterations in zinc transport were not correlated with changes in levels of free zinc ion. The chemical nature of the zinc–amino acid chelate, rather than the chelation itself, appeared to have the most important influence upon zinc absorption. l-histidine, despite a strong zinc-chelating effect, maintained quantitative zinc uptake at control (zinc alone) levels. This effect correlated with the formation of Zn(His)2 species. d-histidine at a luminal concentration of 100 mmol l–1 significantly enhanced subepithelial zinc accumulation, but reduced the fraction of zinc that was retained and absorbed by the fish. The possibility of a Zn(His)2-mediated pathway for intestinal uptake is discussed. l-cysteine specifically stimulated the accumulation of zinc post-intestinally, an effect attributed to enhanced zinc accumulation in the blood. Taurine increased subepithelial zinc accumulation, but decreased the passage of zinc to post-intestinal compartments. Amino acids are proposed to have important roles in modifying intestinal zinc uptake with potential implications for environmental toxicity as well as aquaculture.

Pathophysiological Significance of an Oral Zinc Tolerance Test in Patients with Chronic Hepatic Diseases

1990 ◽  
pp. 99-108
Author(s):  
Yasuyuki Arakawa ◽  
Kazutomo Suzuki ◽  
Keiko Suzuki ◽  
Naohide Tanaka ◽  
Yutaka Matsuo ◽  
...  
Keyword(s):  
Tolerance Test ◽  
Zinc Tolerance ◽  
Hepatic Diseases

A zinc tolerance test

1981 ◽  
Vol 114 (2-3) ◽  
pp. 279-281 ◽  
Author(s):  
J. Pohit ◽  
K.C. Saha ◽  
B. Pal
Keyword(s):  
Tolerance Test ◽  
Zinc Tolerance

Intestinal Absorption of Oligopeptides in Cystinuria

1971 ◽  
Vol 41 (1) ◽  
pp. 23-33 ◽  
Author(s):  
A. M. Asatoor ◽  
M. R. Crouchman ◽  
A. R. Harrison ◽  
F. W. Light ◽  
L. W. Loughridge ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Intestinal Transport ◽  
Tolerance Test ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Test Technique ◽  
Rat Gut

1. The intestinal transport of oligopeptides containing either lysine or arginine has been compared with that of the corresponding free amino acids in six homozygous cystinuric patients and in six normal adult subjects by use of the oral tolerance test technique. 2. No difference was found in the absorption of lysine from l-lysylglycine and an equivalent mixture of free lysine and glycine. 3. In comparisons of serum increments of lysine and arginine after oral casein and an equivalent free amino acid mixture there was no difference in the case of lysine but rise of serum arginine was higher in three cystinuric patients after the whole protein than after the amino acids. 4. Studies of urinary piperidine and pyrrolidine output in a single cystinuric patient supported the results of the tolerance tests. 5. Absorption rates of the dipeptides l-lysylglycine and l-arginyl-l-aspartate from an isolated loop of rat gut are compared with those of an equivalent free amino acid mixture. No difference was found for the former peptide, but in the latter absorption rates of arginine were higher after the amino acid mixture.

Biochemical investigations of CAPD: Plasma levels of trace elements and amino acids and impaired glucose tolerance during the course of treatment

1980 ◽  
Vol 3 (4) ◽  
pp. 237-241
Author(s):  
V.W. Armstrong ◽  
U. Buschmann ◽  
R. Ebert ◽  
C. Fuchs ◽  
J. Rieger ◽  
...  
Keyword(s):  
Amino Acids ◽  
Trace Elements ◽  
Glucose Tolerance ◽  
Impaired Glucose Tolerance ◽  
Preliminary Investigation ◽  
Plasma Concentrations ◽  
Tolerance Test ◽  
Oral Glucose ◽  
Normal Range ◽  
Aluminium Fluoride

Investigations have been initiated into the effect of CAPD on the plasma concentrations of trace elements and amino acids, and in particular the response of patients to an oral glucose tolerance test (OGTT) during the course of treatment. Six months CAPD had no effect on the plasma concentrations of aluminium, fluoride, zinc and copper. Levels of aluminium and fluoride were above the normal range. Loss of amino acids in the dialysate correlated with their plasma concentrations. No changes were observed in the E/NE, Val/Gly or Tyr/Phe ratios during nine months treatment. Five CAPD patients demonstrated an impaired glucose tolerance in response to an OGTT after one month of treatment and a further deterioration occurred in the glucose tolerance of three patients after another six months CAPD. In a preliminary investigation with fructose substituted for glucose in the dialysate of one patient, an improvement in the OGTT and rate of insulin secretion was observed after 3 days dialysis against fructose.

scholarly journals Amino Acid Metabolism in Apicomplexan Parasites

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 61
Author(s):  
Aarti Krishnan ◽  
Dominique Soldati-Favre
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Current Knowledge ◽  
Acid Biosynthesis ◽  
Apicomplexan Parasites ◽  
Obligate Intracellular ◽  
Metabolic Functions ◽  
Transcriptomics Data

Obligate intracellular pathogens have coevolved with their host, leading to clever strategies to access nutrients, to combat the host’s immune response, and to establish a safe niche for intracellular replication. The host, on the other hand, has also developed ways to restrict the replication of invaders by limiting access to nutrients required for pathogen survival. In this review, we describe the recent advancements in both computational methods and high-throughput –omics techniques that have been used to study and interrogate metabolic functions in the context of intracellular parasitism. Specifically, we cover the current knowledge on the presence of amino acid biosynthesis and uptake within the Apicomplexa phylum, focusing on human-infecting pathogens: Toxoplasma gondii and Plasmodium falciparum. Given the complex multi-host lifecycle of these pathogens, we hypothesize that amino acids are made, rather than acquired, depending on the host niche. We summarize the stage specificities of enzymes revealed through transcriptomics data, the relevance of amino acids for parasite pathogenesis in vivo, and the role of their transporters. Targeting one or more of these pathways may lead to a deeper understanding of the specific contributions of biosynthesis versus acquisition of amino acids and to design better intervention strategies against the apicomplexan parasites.

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