scholarly journals Amino acids do not suppress proteolysis in premature neonates

2001 ◽  
Vol 281 (3) ◽  
pp. E472-E478 ◽  
Author(s):  
Brenda B. Poindexter ◽  
Cheryl A. Karn ◽  
Catherine A. Leitch ◽  
Edward A. Liechty ◽  
Scott C. Denne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glucose Production ◽  
Essential Amino Acids ◽  
Endogenous Glucose Production ◽  
Full Term ◽  
Term Neonates ◽  
Premature Neonates ◽  
Amino Acid Infusion ◽  
Amino Acid Availability

To determine whether increased amino acid availability can reduce proteolysis in premature neonates and to assess the capacity of infants born prematurely to acutely increase the irreversible catabolism of the essential amino acids leucine (via oxidation) and phenylalanine (via hydroxylation to form tyrosine), leucine and phenylalanine kinetics were measured under basal conditions and in response to a graded infusion of intravenous amino acids (1.2 and 2.4 g · kg−1 · day−1) in clinically stable premature (∼32 wk gestation) infants in the 1st wk of life. In contrast to the dose-dependent suppression of proteolysis seen in healthy full-term neonates, the endogenous rates of appearance of leucine and phenylalanine (reflecting proteolysis) were unchanged in response to amino acids (297 ± 21, 283 ± 19, and 284 ± 31 μmol · kg−1 · h−1 for leucine and 92 ± 6, 92 ± 4, and 84 ± 7 μmol · kg−1 · h−1 for phenylalanine). Similar to full-term neonates, leucine oxidation (40 ± 5, 65 ± 6, and 99 ± 7 μmol · kg−1 · h−1) and phenylalanine hydroxylation (12 ± 1, 16 ± 1, and 20 ± 2 μmol · kg−1 · h−1) increased in a stepwise fashion in response to graded amino acids. This capacity to increase phenylalanine hydroxylation may be crucial to meet tyrosine needs when exogenous supply is limited. Finally, to determine whether amino acids stimulate glucose production in premature neonates, glucose rate of appearance was measured during each study period. In response to amino acid infusion, rates of endogenous glucose production were unchanged (and near zero).

Effects of infused amino acids on glucose production and utilization in healthy human subjects

1992 ◽  
Vol 262 (6) ◽  
pp. E826-E833 ◽  
Author(s):  
L. Tappy ◽  
K. Acheson ◽  
S. Normand ◽  
D. Schneeberger ◽  
A. Thelin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glucose Oxidation ◽  
Human Subjects ◽  
Glucose Production ◽  
Endogenous Glucose Production ◽  
Amino Acid Infusion ◽  
Glucose Synthesis ◽  
Normal Human ◽  
Endogenous Glucose

Amino acids have been reported to increase endogenous glucose production in normal human subjects during hyperinsulinemia: however, controversy exists as to whether insulin-mediated glucose disposal is inhibited under these conditions. The effect of an amino acid infusion on glucose oxidation rate has so far not been determined. Substrate oxidation rates, endogenous glucose production, and [13C]glucose synthesis from [13C]bicarbonate were measured in six normal human subjects during sequential infusions of exogenous glucose and exogenous glucose with (n = 5) or without (n = 5) exogenous amino acids. Amino acids increased endogenous glucose production by 84% and [13C]glucose synthesis by 235%. Glucose oxidation estimated from indirect calorimetry decreased slightly after amino acids, but glucose oxidation estimated from [13C]glucose-13CO2 data was increased by 14%. It is concluded that gluconeogenesis is the major pathway of amino acid degradation. During amino acid administration, indirect calorimetry underestimates the true rate of glucose oxidation, whereas glucose oxidation calculated from the 13C enrichment of expired CO2 during [U-13C]glucose infusion does not. A slight stimulation of glucose oxidation during amino acid infusion, concomitant with an increased plasma insulin concentration, indicates that amino acids do not inhibit glucose oxidation.

Amino acids suppress proteolysis independent of insulin throughout the neonatal period

1997 ◽  
Vol 272 (4) ◽  
pp. E592-E599 ◽  
Author(s):  
B. B. Poindexter ◽  
C. A. Karn ◽  
J. A. Ahlrichs ◽  
J. Wang ◽  
C. A. Leitch ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Neonatal Period ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Amino Acid Availability ◽  
Dose Dependent Fashion ◽  
Term Newborns ◽  
Dose Dependent ◽  
Acid Administration

To determine how increased amino acid availability alters rates of whole body proteolysis and the irreversible catabolism of the essential amino acids leucine and phenylalanine throughout the neonatal period, leucine and phenylalanine kinetics were measured under basal conditions and in response to intravenous amino acids in two separate groups of healthy, full-term newborns (at 3 days and 3 wk of age). The endogenous rates of appearance of leucine and phenylalanine (reflecting proteolysis) were suppressed equally in both groups and in a dose-dependent fashion (by approximately 10% with 1.2 g x kg(-1) x day(-1) and by approximately 20% with 2.4 g x kg(-1) x day(-1)) in response to intravenous amino acid delivery. Insulin concentrations remained unchanged from basal values during amino acid administration. The irreversible catabolism of leucine and phenylalanine increased in a stepwise fashion in response to intravenous amino acids; again, no differences were observed between the two groups. This study clearly demonstrates that the capacity to acutely increase rates of leucine oxidation and phenylalanine hydroxylation is fully present early in the neonatal period in normal newborns. Furthermore, these data suggest that amino acid availability is a primary regulator of proteolysis in normal newborns throughout the neonatal period.

EFFECT OF STEAM PELLETING AND REGRINDING ON THE DIGESTIBILITY OF PROTEIN IN CEREAL GRAINS, SOYBEAN MEAL AND WHEAT BRAN BY THE RAT

1968 ◽  
Vol 48 (1) ◽  
pp. 35-39 ◽  
Author(s):  
E. M. Olsen ◽  
S. J. Slinger
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Wheat Bran ◽  
Soybean Meal ◽  
Protein Digestibility ◽  
Essential Amino Acids ◽  
Cereal Grains ◽  
Protein Utilization ◽  
Amino Acid Availability ◽  
Net Protein

The effect if steam pelleting and regrinding on digestibility of protein in corn, wheat, barley, oats, soybean meal and wheat bran was tested with rats. Percentage amino acid absorption and net protein utilization (NPU) were determined for the wheat bran. Pelleting and regrinding improved the digestibility of protein in bran but had no effect on the digestibility of protein in the other ingredients tested. Increased absorption of amino acids caused by the increased digestibility of protein in bran varied considerably for individual amino acids, being greatest for isoleucine, lysine, methionine and threonine of the essential amino acids. The improvement in protein digestibility and amino acid availability was reflected in a higher NPU.

Protein degradation and synthesis measured with multiple amino acid tracers in vivo

1996 ◽  
Vol 271 (4) ◽  
pp. E733-E741 ◽  
Author(s):  
P. Tessari ◽  
R. Barazzoni ◽  
M. Zanetti ◽  
M. Vettore ◽  
S. Normand ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein S ◽  
Essential Amino Acids ◽  
Body Protein ◽  
Amino Acid Availability ◽  
Before And After ◽  
Branched Chain ◽  
Multiple Amino Acid

Whether tracers of different essential amino acids yield the same estimates of body protein turnover is still uncertain. Therefore, we have simultaneously determined leucine (Leu; using [14C]Leu), phenylalanine (Phe; using [13C]Phe), and tyrosine (Tyr; using [2H2]Tyr) rates of appearance (Ra) from proteolysis (PD), as well as Leu and Phe disposal, into protein synthesis (PS) both before and after an anabolic stimulus in healthy volunteers. Protein anabolism was stimulated by insulin plus a branched-chain amino acid-enriched aromatic amino acid-deficient amino acid solution, which increased Leu (from 145 +/- 9 to 266 +/- 10 mumol/l) but decreased Phe (from 57 +/- 2 to 46 +/- 3) and Tyr (from 58.7 +/- 5.5 to 21.0 +/- 2.2) concentrations. Postabsorptive endogenous Leu Ra (2.04 +/- 0.12 mumol.kg-1.min-1), Phe Ra (0.66 +/- 0.03), and Tyr Ra (0.45 +/- 0.06), as well as rates of PS determined with the leucine (1.65 +/- 0.10 mumol.kg-1.min-1) and the phenylalanine tracer (0.57 +/- 0.03), agreed well with the known abundance of these amino acids in body protein(s). After insulin and amino acids, PD was suppressed (P < 0.001) using all tracers. However, although percent suppression of endogenous Leu Ra (-->1.49 +/- 0.10 mumol.kg-1.min-1, 26 +/- 5%) and Phe Ra (-->0.53 +/- 0.02 mumol.kg-1.min-1, -20 +/- 2%) were comparable, endogenous Tyr Ra was suppressed to a larger extent (-->0.23 +/- 0.02 mumol.kg-1.min-1, -46 +/- 3% P = 0.038). PS was stimulated using the Leu (+24 +/- 7%, P < 0.02) but not the Phe (+6 +/- 4%, not significant) data. We conclude that isotopes of different essential amino acid: provide comparable estimates of PD and PS in the postabsorptive state. However, their responses to an anabolic stimulus may differ, possibly depending on exogenous amino acid availability and/or the resulting plasma levels.

scholarly journals Amino acid availability is not essential for lifespan extension by dietary restriction in the fly

2021 ◽  
Author(s):  
Sarah L Gautrey ◽  
Mirre J P Simons
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Restriction ◽  
Large Scale ◽  
Essential Amino Acids ◽  
Nutrient Sensing ◽  
Amino Acid Availability ◽  
Environmental Interactions ◽  
Optimal Health ◽  
Dietary Component

Dietary restriction (DR) is one of the most potent ways to extend health- and lifespan. Key progress in understanding the mechanisms of DR, and ageing more generally, was made when dietary protein, and more specifically essential amino acids (EAA), were identified as the key dietary component to restrict to obtain DRs health and lifespan benefits. This role of dietary amino acids has strongly influenced work on ageing mechanisms, especially in nutrient sensing, e.g. Tor and insulin(-like) signalling networks. Experimental biology in Drosophila melanogaster has been instrumental in generating and confirming the now dominant hypothesis that EAA availability is central to ageing. Here, we expand on previous work testing the involvement of EAA in DR through large scale (N=6,238) supplementation experiments across four diets and two genotypes in female flies. Surprisingly, we find that EAA are not essential to DRs lifespan benefits. Importantly, we do identify the fecundity benefits of EAA supplementation suggesting the supplemented EAA were bioavailable. Furthermore, we find that the effects of amino acids on lifespan vary by diet and genetic line studied and that at our most restricted diet fecundity is constrained by other nutrients than EAA. We suggest that DR for optimal health is a concert of nutritional effects, orchestrated by genetic, diet and environmental interactions. Our results question the universal importance of amino acid availability in the biology of ageing and DR.

Screening of amino acid constituents from date palm fruits

2016 ◽  
Vol 5 (10) ◽  
pp. 4972
Author(s):  
Lata Birlangi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
United Arab Emirates ◽  
Nutritional Value ◽  
Date Palm ◽  
Amino Acid Content ◽  
Essential Amino Acids ◽  
Cultivated Plants ◽  
Palm Fruits ◽  
Social Part

The date palm (Phoenix dactylifera L.) is one of mankind’s oldest cultivated plants. The fruit of the date palm is an important crop of the hot arid and semi-arid regions of the world. It has always played a genuine economic and social part in the lives of the people of these areas. The present objective in examining the amino acid content of different varieties of date palm fruits from Middle-East region; is to determine whether its protein could effectively supplement the nutritional value and it is also aimed in finding which variety is rich in number of amino acids. The phytochemical screening revealed the presence of eight essential amino acids and five non-essential amino acids in the date fruits. Among all the date fruit varieties taken as samples for the study, Dabbas cultivar of United Arab Emirates found to exhibit eight types of amino acids which includes five as non-essential ones. Total of thirteen amino acids were detected in the seven date cultivars. Determination of amino acid can serve as a guide to the possible nutritional value.

scholarly journals Progress towards reduced-crude protein diets for broiler chickens and sustainable chicken-meat production

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sonia Yun Liu ◽  
Shemil P. Macelline ◽  
Peter V. Chrystal ◽  
Peter H. Selle
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Broiler Chickens ◽  
Crude Protein ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Chicken Meat ◽  
Meat Production ◽  
Accurate Identification ◽  
Reduced Crude Protein

AbstractThe prime purpose of this review is to explore the pathways whereby progress towards reduced-crude protein (CP) diets and sustainable chicken-meat production may be best achieved. Reduced-CP broiler diets have the potential to attenuate environmental pollution from nitrogen and ammonia emissions; moreover, they have the capacity to diminish the global chicken-meat industry’s dependence on soybean meal to tangible extents. The variable impacts of reduced-CP broiler diets on apparent amino acid digestibility coefficients are addressed. The more accurate identification of amino acid requirements for broiler chickens offered reduced-CP diets is essential as this would diminish amino acid imbalances and the deamination of surplus amino acids. Deamination of amino acids increases the synthesis and excretion of uric acid for which there is a requirement for glycine, this emphasises the value of so-called “non-essential” amino acids. Starch digestive dynamics and their possible impact of glucose on pancreatic secretions of insulin are discussed, although the functions of insulin in avian species require clarification. Maize is probably a superior feed grain to wheat as the basis of reduced-CP diets; if so, the identification of the underlying reasons for this difference should be instructive. Moderating increases in starch concentrations and condensing dietary starch:protein ratios in reduced-CP diets may prove to be advantageous as expanding ratios appear to be aligned to inferior broiler performance. Threonine is specifically examined because elevated free threonine plasma concentrations in birds offered reduced-CP diets may be indicative of compromised performance. If progress in these directions can be realised, then the prospects of reduced-CP diets contributing to sustainable chicken-meat production are promising.

scholarly journals Further evidence that mechanisms of host/symbiont integration are dissimilar in the maternal versus embryonic Acyrthosiphon pisum bacteriome

EvoDevo ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Celeste R. Banfill ◽  
Alex C. C. Wilson ◽  
Hsiao-ling Lu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acyrthosiphon Pisum ◽  
Essential Amino Acids ◽  
Developmental Time ◽  
Follicular Epithelium ◽  
Future Research ◽  
Buchnera Aphidicola ◽  
Bacterial Endosymbionts ◽  
Asexual Embryogenesis

Abstract Background Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis. Results During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity. Conclusions Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.

The screening and preliminary construction of quality mutant population for cultivar “Nipponbare” in japonica rice (Oryza sativa)

Biologia ◽  
2012 ◽  
Vol 67 (6) ◽  
Author(s):  
Da Zhang ◽  
Jian Wu ◽  
Guan Li ◽  
Chun Shi
Keyword(s):  
Amino Acids ◽  
Oryza Sativa ◽  
Amino Acid ◽  
Mutation Frequency ◽  
Near Infrared ◽  
Essential Amino Acids ◽  
Japonica Rice ◽  
Near Infrared Reflectance ◽  
Mutant Population ◽  
Nonessential Amino Acids

AbstractProgenies of Oryza sativa cv. Nipponbare induced with 0.4% ethyl methane sulphonate (EMS) were screened for quality mutants and the preliminary quality mutant population was constructed in present experiment. A total of 2210 materials were first screened using near infrared reflectance spectroscopy (NIRS) from which 208 quality mutants were obtained for a second screening and then yielded 73 quality mutants including amylase content (AC), gel consistency (GC), gelatinization temperature (GT), protein content (PC), rapid viscosity analysis (RVA) parameters and amino acid contents. The screening yielded 11 PC mutants with a mutation frequency of 4.98‰, followed by 7 rice floury viscosity mutants (3.17‰), 5 AC mutants (2.26‰), 4 chalky mutants, GT and GC mutants (1.81‰), and 2 ASV mutants (0.9‰). The relative contents of 17 kinds of amino acid mutations, including 7 kinds for essential amino acids and 10 kinds for nonessential amino acids were identified. With the variation of 10% as the screening standard, mutants were obtained for lysine and leucine at 0.45‰ and for valine at 4.98‰, but no mutants were found for isoleucine, phenylalanine, threonine. For nonessential amino acids, mutants of glutamic (0.45‰), arginine (3.62‰), alanine (3.17‰), serine (0.45‰), glycine (0.45‰), tyrosine (1.81‰), proline (2.71‰), and histidine (0.45‰) were obtained, but none was found for aspartic, phenylalanine nor threonine. At 100% as the screening standard for methionine and cysteines, the mutation frequency of these two amino acid mutants were 0.9‰ and 4.98‰ respectively. Quality mutants in this preliminary library of rice could play important role in gene function and breeding of rice quality.

MATHEMATICAL MODELS FOR THE SYNTHESIS OF PLANT-BASED COMPOSITIONS WITH IMPROVED AMINO ACID COMPOSITION

2021 ◽  
Author(s):  
Irina Gaivoronskaya ◽  
Valenitna Kolpakova
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mathematical Models ◽  
Functional Properties ◽  
Amino Nitrogen ◽  
Essential Amino Acids ◽  
Major Allergen ◽  
Structural Features ◽  
Covalent Bonds ◽  
Pea Protein

The aim of the work was to optimize the process of obtaining multicomponent protein compositions with high biological value and higher functional properties than the original vegetable protein products. Was realized studies to obtain biocomposites on the base of pea protein-oat protein and pea protein-rice protein. Developed composites were enriched with all limited amino acids. For each of the essential amino acids, the amino acid score was 100% and higher. Protein products used in these compositions are not in major allergen list, which allows to use these compositions in allergen-free products and specialized nutrition. To determine biosynthesis parameters for compositions from pea protein and various protein concentrates with the use of transglutaminase enzyme, was studied effect of concentration and exposition time on the amount of amino nitrogen released during the reaction. Decreasing of amino nitrogen in the medium indicated the occurrence of a protein synthesis reaction with the formation of new covalent bonds. Were determined optimal parameters of reaction: the hydromodule, the exposure time, the concentration of EP of the preparation, were obtained mathematical models. Studies on the functional properties of composites, the physicochemical properties of the proteins that make up their composition, and structural features will make it possible to determine the uses in the manufacture of food products based on their ability to bind fat, water, form foam, gels, and etc.

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