scholarly journals Efficiency of utilization of essential amino acids in growing rats at different levels of intake

1985 ◽  
Vol 54 (2) ◽  
pp. 499-508 ◽  
Author(s):  
J. Heger ◽  
Z. Frydrych
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
N Balance ◽  
Growing Rats ◽  
Dietary Concentration ◽  
Limiting Amino Acid ◽  
Maintenance Requirements ◽  
Different Levels

1. Nitrogen balance was studied in growing male SPF-rats fed on diets in which each essential amino acid was varied from zero to about 120% of optimum requirement. From the balance results, optimum and maintenance requirements were estimated as well as the efficiency of utilization of amino acids for growth and growth + maintenance.2. N balance increased with increasing dietary level of the deficient amino acid; the response gradually diminished as the content of the amino acid approached optimum. At zero level of intake, negative N balance was found for all amino acids except histidine. The highest loss of body N was found in the sulphur-amino-acid-free diet and the lowest one in the lysine-free diet.3. Maximal utilization of essential amino acids for growth was found at dietary levels corresponding to 30–60% of optimum requirement and ranged from about 0.65 to 0.85 except for S amino acids and histidine. The utilization of S amino acids was about 0.55 while that of histidine exceeded 1.0. The utilization of amino acids for growth-tmaintenance was maximal at the lowest levels of intake and gradually decreased as the dietary concentration of the limiting amino acid increased. At dietary levels near optimum the utilization was about 06–07, except for S amino acids where the utilization was less than 0.5.

Effect of dietary limiting amino acid in prepyriform cortex on meal patterns

1990 ◽  
Vol 259 (4) ◽  
pp. R716-R723 ◽  
Author(s):  
J. L. Beverly ◽  
D. W. Gietzen ◽  
Q. R. Rogers
Keyword(s):  
Amino Acids ◽  
Cerebrospinal Fluid ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Dark Period ◽  
Essential Amino Acids ◽  
Dark Phase ◽  
Artificial Cerebrospinal Fluid ◽  
Limiting Amino Acid ◽  
Prepyriform Cortex

Microinjection of the dietary limiting essential amino acid (DLAA) into the prepyriform cortex (PPC) increased intake of a diet having an imbalance among the essential amino acids (imbalanced diet) from 50-55% of baseline, when artificial cerebrospinal fluid (aCSF) was injected, to 70-75% of baseline. The increase in intake of the imbalanced diet by DLAA injection became apparent after 3-6 h and was maintained throughout the dark period. Meal size, meal duration, and the number of meals returned to normal after bilateral injections of the DLAA into the PPC of rats fed the imbalanced diet. Injection of the DLAA 30 min before the onset of the dark phase increased intake of imbalanced diet to 70% of baseline intake. When injections of threonine or isoleucine were made 6 and 3 h, respectively, prior to onset of the dark phase, intake of imbalanced diet increased to 85% of baseline intake. Results suggest that some form of processing of the injected DLAA within the PPC is necessary to increase the intake of imbalanced diets.

scholarly journals Non-essential nitrogen and protein utilization in the growing rat

1990 ◽  
Vol 64 (3) ◽  
pp. 653-661 ◽  
Author(s):  
J. Heger
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Protein Utilization ◽  
Biological Value ◽  
Growing Rats ◽  
Growing Rat ◽  
Per Se

Three series of nitrogen-balance experiments were carried out on growing rats fed on purified isonitrogenous diets (16 g N/kg) to study the importance of non-essential N and the essential:total N (E:T) ratio for attaining maximum N balance (NB) and biological value (BV) of protein. Minimum dietary levels of asparagine, proline and glutamic acid required for maximum NB and BV were estimated to be 1.0, 2.0 and 5.0 g/kg respectively. In an essential amino acid-based diet, the levels of individual amino acids were successively reduced to 110% of the requirement. Reducing the level of arginine, lysine or methionine + cystine resulted in a significant increase in NB and BV while the response of rats given the isoleucine-reduced diet significantly decreased. Addition of asparagine, proline and glutamic acid in the estimated minimum amounts to an essential amino acid-based diet resulted in a significant increase in NB and BV. A further significant increase was found when the levels of arginine, lysine and methionine + cystine in the diet were reduced to 110 % of the requirement. The performance of rats fed on the latter diet was similar to that of rats given a diet with the optimum E:T ratio. It is concluded that the optimum protein utilization may be influenced by the presence of some non-essential amino acids and by the surplus of some essential amino acids rather than by the E:T ratio per se.

scholarly journals Amino Acid Profiles of the Flesh of the Heterosexual Pairs of Neopetrolisthes maculatus

2017 ◽  
Vol 61 ◽  
pp. 23-35 ◽  
Author(s):  
Emmanuel Ilesanmi Adeyeye
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Efficiency Ratio ◽  
Amino Acids Composition ◽  
Amino Acid Requirements ◽  
Amino Acid Profiles ◽  
Limiting Amino Acid ◽  
Acid Index

This paper reports on amino acid profiles of the flesh of heterosexuals of porcellanids collected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. Results showed that high values of amino acids were observed in the heterosexual flesh of Neopetrolisthes maculatus (g 100g-1 protein): 17.7 – 17.8 (Glu), 9.90 – 10.0 (Asp), 8.70 – 9.07 (Arg), 7.23 – 7.94 (Leu) and 5.81 – 6.06 (Gly). Total essential amino acid values ranged from 45.2 – 46.2 g 100-1g. Predicted protein efficiency ratio was 3.82 – 4.14, the range of essential amino acid index was 86.9 – 89.9, the biological values ranged from 83.0 – 86.3. The Lys/Trp was 3.31-4.27. Serine was limiting amino acid (0.513 – 0.516) in the egg score comparison; under the essential amino acids scores, Lys (0.840) was limiting in female but Val (0.823) was limiting in the male; Lys (0.796 – 0.905) was limiting in both samples in the pre-school child amino acid requirements. It was observed that out of the twenty parameters determined, male flesh was more concentrated in 60% values than the female flesh and 40% better in female than male. Correlation coefficient result showed that significant differences existed in the amino acids composition at r = 0.01 of the N. maculatus samples.

scholarly journals The Diverse Functions of Non-Essential Amino Acids in Cancer

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 675 ◽  
Author(s):  
Bo-Hyun Choi ◽  
Jonathan L. Coloff
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cancer Therapy ◽  
Metabolic Pathways ◽  
Essential Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Essential Amino Acids ◽  
Redox Status ◽  
Antioxidant Systems

Far beyond simply being 11 of the 20 amino acids needed for protein synthesis, non-essential amino acids play numerous important roles in tumor metabolism. These diverse functions include providing precursors for the biosynthesis of macromolecules, controlling redox status and antioxidant systems, and serving as substrates for post-translational and epigenetic modifications. This functional diversity has sparked great interest in targeting non-essential amino acid metabolism for cancer therapy and has motivated the development of several therapies that are either already used in the clinic or are currently in clinical trials. In this review, we will discuss the important roles that each of the 11 non-essential amino acids play in cancer, how their metabolic pathways are linked, and how researchers are working to overcome the unique challenges of targeting non-essential amino acid metabolism for cancer therapy.

An optimal dietary amino acid pattern for growing pigs

1997 ◽  
Vol 1987 ◽  
pp. 91-91 ◽  
Author(s):  
T. C. Wang ◽  
M. F. Fuller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Retention ◽  
Essential Amino Acids ◽  
Growing Pigs ◽  
Amino Acid Pattern ◽  
Dietary Amino Acid ◽  
Ideal Protein ◽  
Limiting Amino Acid ◽  
The Ideal

An animal's rate of protein accretion (or nitrogen retention) is determined by the most deficient (or first limiting) amino acid in the diet, in a perfectly balanced (or ideal) protein all essential amino acids and the sum of the non-essential amino acids are equally limiting. If a dietary protein had any amino acids in excess of the ideal pattern, then the removal of any of the excess should not affect nitrogen retention. This principle was used to determine the ideal dietary amino acid pattern for growing pigs.Three nitrogen balance trials were carried out with a total of 64 gilts of weight from 30 to 55 kg. Casein and a mixture of amino acids were used in the semi-purified diets. The animals were given the diets at the rate of 93 g/kg BW0.75/d in three equal meals mixed with 0.3 L water. The feeding times were 08.30, 12.30 and 17.30. All pigs received their experimental diets for 7 days, made up of 3 days preliminary and a 4-day collection, except that the preliminary period before the first collection in the first period was 7 days. Before the first collection bladder catheters were introduced.

scholarly journals Nutritional interventions in sarcopenia: a critical review

2015 ◽  
Vol 74 (4) ◽  
pp. 378-386 ◽  
Author(s):  
Mary Hickson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscle Mass ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Protein Supplementation ◽  
Nutrition Intervention ◽  
Nutritional Interventions ◽  
Intervention Trials ◽  
Nutritional Studies

The aim of the present paper is to critically review the details of the published nutrition intervention trials, with and without exercise, targeting sarcopenia. Sarcopenia is the loss of muscle mass, strength and/or performance with age. Since amino acids and energy are required for muscle synthesis it is possible that nutritional intake influences sarcopenia. Nutritional studies are challenging to carry out because of the complexity of modulating dietary intake. It is very difficult to change one nutrient without influencing many others, which means that many of the published studies are problematic to interpret. The studies included evaluate whole protein, essential amino acids and β-hydroxyl β-methylbutyrate (HMB). Whole-protein supplementation failed to show a consistent effect on muscle mass, strength or function. This can be explained by the variations in study design, composition of the protein supplement and the failure to monitor voluntary food intake, adherence and baseline nutritional status. Essential amino-acid supplements showed an inconsistent effect but there are only two trials that have significant differences in methodology and the supplement used. The HMB studies are suggestive of a beneficial effect on older adults, but larger well-controlled studies are required that measure outcomes relevant to sarcopenia, ideally in sarcopenic populations. The issues of timing and distribution of protein intake, and increased splanchnic amino-acid sequestration are discussed, and recommendations for future trials are made.

Optimum dietary amino acid pattern and limiting order of some essential amino acids for growing-furring blue foxes (Alopex lagopus)

2004 ◽  
Vol 78 (1) ◽  
pp. 77-86 ◽  
Author(s):  
T. Dahlman ◽  
J. Valaja ◽  
E. Venäläinen ◽  
T. Jalava ◽  
I. Pölönen
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Control Diet ◽  
Essential Amino Acids ◽  
Amino Acid Pattern ◽  
N Retention ◽  
Low Protein ◽  
Acid Control ◽  
Blue Fox ◽  
Limiting Amino Acid

AbstractThe optimum pattern and limiting order of some essential amino acids for growing-furring blue foxes were assessed from nitrogen (N) retention responses. Total tract digestibility and N balance trials were carried out on 24 weaned blue fox males in an 8 ✕ 5 cyclic change-over experiment. Eight experimental diets were prepared by removing proportionately about 0·4 of each of the amino acids studied – methionine + cystine, lysine, threonine, tryptophan and histidine – successively from the amino acid control diet. The main source of protein in the amino acid control diet was casein and an amino acid mixture was added to bring the calculated crude protein (CP) content up to the level of 170 g/kg dry matter (DM). Low-protein (CP 95·7 g/kg DM) and high-protein (CP 166·6 g/kg DM) diets, the protein proportion of which was casein protein, served as negative and positive control diets, respectively. The reduction in N retention when one amino acid in turn was deleted from the amino acid control diet was calculated, and a regression analysis was made between N retention and relative amino acid intake. Data on the animals’ intake of each limiting amino acid and those on the amino acid control diet were used. The optimum amino acid pattern, expressed relative to lysine = 100, proved to be: methionine + cystine 77, threonine 64, histidine 55 and tryptophan 22. The first-limiting amino acids were methionine + cystine. Blue fox responses (N retention, weight gain) to deletion of methionine + cystine from the diet were very severe and exceeded those to deletion of any other amino acid. Moreover, removing methionine + cystine from the diet significantly impaired the apparent digestibility of organic matter, reducing it to a level even lower than that of the low-protein diet. After methionine + cystine, the next-limiting amino acid in casein-based diets was threonine, followed by histidine and tryptophan. The results show the importance of verifying the sufficiency of dietary methionine + cystine in the practical feeding of blue foxes.

Effect of diet and infusion of volatile fatty acids into the rumen on the concentration of plasma free amino acids in sheep

1982 ◽  
Vol 48 (3) ◽  
pp. 519-526 ◽  
Author(s):  
J. R. Mercer ◽  
E. L. Miller
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Volatile Fatty Acids ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Protein Nitrogen ◽  
Post Infusion ◽  
Limiting Amino Acid ◽  
The Mean

1. The effect of supplementing barley diets with urea (U), extracted decorticated groundnut meal (GNM) or Peruvian fish meal (PFM) on plasma free amino acid concentrations in sheep have been examined and the first limiting amino acid has been indicated by measuring the changes in the concentration of the plasma essential amino acids (PEAA) during a rumen infusion of a volatile fatty acid (VFA) mixture.2. Three wethers fitted with rumen and re-entrant duodenal cannulas were given isonitrogenous, isoenergetic diets containing (g/kg dry matter (DM)) U 20, GNM 106 or PFM 78, the crude protein (nitrogen × 6.25) contents being 139, 145 and 148 respectively. The sheep were fed hourly, the mean daily dm intake being 0.634 kg.3. Plasma concentrations of valine, threonine, lysine, isoleucine and leucine were linearly related to their concentrations in duodenal digesta.4. A VFA mixture was infused into the rumen for 6 h to supply (mmol/min) acetate 1.47, propionate 0.22 and n-butyrate 0.27. Blood samples were taken 6 h before, during and 12 h after the end of the infusion.5. The concentration of all PEAA decreased relative to the pre-infusion and post-infusion controls but there were no significant differences between diets.6. The mean decreases in concentration averaged over all three diets showed that the decrease in concentration of methionine (41.5%) was far greater than for any other essential amino acid suggesting that under these conditions methionine was the first limiting amino acid.

scholarly journals Current World Supplies of and Requirements for Essential Amino Acids

1991 ◽  
Vol 13 (1) ◽  
pp. 1-12
Author(s):  
Hoshiai Kazuo
Keyword(s):  
Amino Acid ◽  
Essential Amino Acid ◽  
Essential Amino Acids ◽  
Gdp Per Capita ◽  
Amino Acid Requirement ◽  
Balance Sheets ◽  
Amino Acid Data ◽  
Limiting Amino Acid ◽  
Per Capita ◽  
Food Commodities

Correlations of GDP per capita per year with total protein supplies per capita per day and animal-protein ratios were computed by pooling data prom 164 countries. Average supplies for 1972–1974, 1975–1977, 1979–1981, and 1984–1986 were determined from FAO food balances sheets. Essential amino acid (EAA) supplies by country were computed using amino acid data for food commodities shown in FAO food balance sheets and other data. The EAA requirements for the four periods were estimated by country. When the latest amino acid requirement estimates are used, lysine is the limiting amino acid in all predominantly cereal diets.

scholarly journals Symbiotic bacteria enable insect to use a nutritionally inadequate diet

2008 ◽  
Vol 276 (1658) ◽  
pp. 987-991 ◽  
Author(s):  
E Akman Gündüz ◽  
A.E Douglas
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Essential Amino Acid ◽  
Acyrthosiphon Pisum ◽  
Amino Acid Content ◽  
Symbiotic Bacterium ◽  
Essential Amino Acids ◽  
Symbiotic Bacteria ◽  
Protein Amino Acid ◽  
Phloem Sap

Animals generally require a dietary supply of various nutrients (vitamins, essential amino acids, etc.) because their biosynthetic capabilities are limited. The capacity of aphids to use plant phloem sap, with low essential amino acid content, has been attributed to their symbiotic bacteria, Buchnera aphidicola , which can synthesize these nutrients; but this has not been demonstrated empirically. We demonstrate here that phloem sap obtained from the severed stylets of pea aphids Acyrthosiphon pisum feeding on Vicia faba plants generally provided inadequate amounts of at least one essential amino acid to support aphid growth. Complementary analyses using aphids reared on chemically defined diets with each amino acid individually omitted revealed that the capacity of the symbiotic bacterium B. aphidicola to synthesize essential amino acids exceeded the dietary deficit of all phloem amino acids except methionine. It is proposed that this shortfall of methionine was met by aphid usage of the non-protein amino acid 5-methylmethionine in the phloem sap. This study provides the first quantitative demonstration that bacterial symbiosis can meet the nutritional demand of plant-reared aphids. It shows how symbiosis with micro-organisms has enabled this group of animals to escape from the constraint of requiring a balanced dietary supply of amino acids.

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