scholarly journals Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in young chicks

1997 ◽  
Vol 78 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Hardy M Edwards III ◽  
David H Baker ◽  
Sergio R Fernandez ◽  
Carl M Parsons
Keyword(s):  
Amino Acids ◽  
Weight Gain ◽  
Amino Acid ◽  
Feed Efficiency ◽  
Regression Line ◽  
Whole Body ◽  
Broiler Chicks ◽  
Body Protein ◽  
Maximal Weight ◽  
Indispensable Amino Acids

Broiler chicks were fed on chemically-defined crystalline amino acid diets containing graded levels of L-threonine (Thr) during the period 10–20 d post-hatching. Doses of Thr represented 5,10,15,40,55,70 and 95% of its ideal level for maximal weight gain and feed efficiency. Other amino acids were maintained at minimized excess levels that were 15% (of ideal) above the various doses of Thr. Following 10d of feeding and a 24h fast, chicks were killed for whole-body protein and amino acid analysis. Using pen accretion means, weight gain (r20·98), protein accretion (r2 0·99), and Thr accretion (r2 0·99) were linear (P<0·01) functions of Thr intake. Slope of the Thr accretion regression line indicated that 82% of the Thr intake was recovered in whole-body protein. At zero Thr intake, chicks lost 11·9 mg Thr/d. The Thr maintenance requirement was 45·7 mg/d per kg body weight 0·75. Increasing doses of Thr resulted in increased (P<0·05) concentrations of methionine, isoleucine, histidine and lysine in whole-body protein. Other indispensable amino acids, including Thr, also tended to increase. Whole-body glycine, proline, serine and cystine concentrations decreased (P<0·05) as Thr was increased in the diet. The maintenance need for Thr represented 5·5% of the total need for Thr. The data suggest that efficiency of Thr utilization is constant at all levels of Thr intake between 5 and 95% of the level required for maximal weight gain and feed efficiency.

scholarly journals Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in Atlantic salmon (Salmo salar L.) fry

2006 ◽  
Vol 95 (2) ◽  
pp. 234-245 ◽  
Author(s):  
Rollin Xavier ◽  
Jean-Baptiste Wauters ◽  
Noélie Bodin ◽  
Yvan Larondelle ◽  
Wilfried Ooghe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Regression Line ◽  
Whole Body ◽  
Body Protein ◽  
Protein Deposition ◽  
Salmon Fry ◽  
Indispensable Amino Acids

Eighteen groups of seventy Atlantic salmon (Salmo salar L.) fry (initial mean body weight 0·8 (sd 0·01) g) were fed on semi-purified diets containing graded levels of l-threonine (Thr) in 15 litres aquaria at a temperature of 14·5±1°C. Doses of Thr represented 1, 31, 41, 51, 62, 72, 83 and 93% of its ideal level for optimumprotein deposition. Indispensable amino acids other than Thr were included in the same proportion (on a g/16g N basis) as in the Atlantic salmon fry whole-body carcass. Following 36d of feeding and a 36h fast, fry were killed for whole-body protein and amino acid analysis. Weight gain (r2 0·98), protein accretion (r2 0·97), and Thr accretion (r2 0·97) were linear (P<0·01) functions of Thr intake. Slope of the Thr accretion regression line showed that the efficiency of Thr utilisation above maintenance was 76%. At zero Thr intake, fry lost 5·4mg Thr/kg body weight0·75 per d. The Thr maintenance requirement was 7·2mg/kg body weight0·75 per d and the Thr requirement for growth was 66mg for 1g protein deposition. Increasing doses of Thr resulted in increased (P<0·05) concentrations of histidine and lysine, and decreased concentrations of isoleucine in whole-body protein. The maintenance need for Thr represented 13·4% of the total need for Thr. The data suggest that efficiency of Thr utilisation above maintenance is constant at all levels of Thr intake between 1 and 93% of the level required for optimum protein deposition.

scholarly journals Nonessential amino acid usage for protein replenishment in humans: a method of estimation

2019 ◽  
Vol 110 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Paolo Tessari
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Quality ◽  
Essential Amino Acids ◽  
World Health ◽  
Whole Body ◽  
Published Data ◽  
Total Proteins ◽  
Body Protein ◽  
Amino Acid Turnover

ABSTRACT Background Essential amino acids (EAAs) are key factors in determining dietary protein quality. Their RDAs have been estimated. However, although nonessential amino acids (NEAAs) are utilized for protein synthesis too, no estimates of their usage for body protein replenishment have been proposed so far. Objective The aim of this study was to provide minimum, approximate estimates of NEAA usage for body protein replenishment/conservation in humans. Methods A correlation between the pattern of both EAAs and NEAAs in body proteins, and their usage, was assumed. In order to reconstruct an “average” amino acid pattern/composition of total body proteins (as grams of amino acid per gram of protein), published data of relevant human organs/tissues (skeletal muscle, liver, kidney, gut, and collagen, making up ∼74% of total proteins) were retrieved. The (unknown) amino acid composition of residual proteins (∼26% of total proteins) was assumed to be the same as for the sum of the aforementioned organs excluding collagen. Using international EAA RDA values, an average ratio of EAA RDA to the calculated whole-body EAA composition was derived. This ratio was then used to back-calculate NEAA usage for protein replenishment. The data were calculated also using estimated organ/tissue amino acid turnover. Results The individual ratios of World Health Organization/Food and Agriculture Organization/United Nations University RDA to EAA content ranged between 1.35 (phenylalanine + tyrosine) and 3.68 (leucine), with a mean ± SD value of 2.72 ± 0.81. In a reference 70-kg subject, calculated NEAA usage for body protein replenishment ranged from 0.73 g/d for asparagine to 3.61 g/d for proline. Use of amino acid turnover data yielded similar results. Total NEAA usage for body protein replenishment was ∼19 g/d (45% of total NEAA intake), whereas ∼24 g/d was used for other routes. Conclusion This method may provide indirect minimum estimates of the usage of NEAAs for body protein replacement in humans.

scholarly journals Consumption of a Specially-Formulated Mixture of Essential Amino Acids Promotes Gain in Whole-Body Protein to a Greater Extent than a Complete Meal Replacement in Older Women with Heart Failure

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1360 ◽  
Author(s):  
Il-Young Kim ◽  
Sanghee Park ◽  
Ellen T. H. C. Smeets ◽  
Scott Schutzler ◽  
Gohar Azhar ◽  
...  
Keyword(s):  
Heart Failure ◽  
Amino Acids ◽  
Amino Acid ◽  
Body Mass ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Meal Replacement ◽  
Anabolic Response ◽  
Body Protein ◽  
Net Protein

Heart failure in older individuals is normally associated with a high body mass index and relatively low lean body mass due to, in part, a resistance to the normal anabolic effect of dietary protein. In this study we have investigated the hypothesis that consumption of a specially-formulated composition of essential amino acids (HiEAAs) can overcome anabolic resistance in individuals with heart failure and stimulate the net gain of body protein to a greater extent than a commercially popular protein-based meal replacement beverage with greater caloric but lower essential amino acid (EAA) content (LoEAA). A randomized cross-over design was used. Protein kinetics were determined using primed continuous infusions of L-(2H5)phenylalanine and L-(2H2)tyrosine in the basal state and for four hours following consumption of either beverage. Both beverages induced positive net protein balance (i.e., anabolic response). However, the anabolic response was more than two times greater with the HiEAA than the LoEAA (p < 0.001), largely through a greater suppression of protein breakdown (p < 0.001). Net protein accretion (g) was also greater in the HiEAA when data were normalized for either amino acid or caloric content (p < 0.001). We conclude that a properly formulated EAA mixture can elicit a greater anabolic response in individuals with heart failure than a protein-based meal replacement. Since heart failure is often associated with obesity, the minimal caloric value of the HiEAA formulation is advantageous.

Meal stimulation of albumin synthesis: a significant contributor to whole body protein synthesis in humans

1992 ◽  
Vol 263 (4) ◽  
pp. E794-E799 ◽  
Author(s):  
P. De Feo ◽  
F. F. Horber ◽  
M. W. Haymond
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Combined Treatment ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Albumin Synthesis ◽  
Body Protein ◽  
Peripheral Tissues ◽  
Stimulation Of

The present studies were performed to test the hypothesis that the liver, by increasing the synthesis of specific plasma proteins during the absorption of an amino acid meal, may play an important role in the temporary "storage" of ingested essential amino acids and to explore the effects of glucocorticosteroids and recombinant human growth hormone (rhGH) on these processes. The fractional synthetic rates of albumin and fibrinogen were determined using simultaneous infusions of intravenous [1-14C]leucine and intraduodenal [4,5-3H]leucine after 22 h fasting and during absorption of glucose and amino acids in four groups of normal subjects treated for 1 wk with placebo, prednisone (0.8 mg.kg-1.day-1), rhGH (0.1 mg.kg-1.day-1), or combined treatment. When compared with the fasted state and independent of the route of tracer delivery and hormonal treatment, albumin, but not fibrinogen, synthesis increased (P < 0.0001) during absorption of a mixed glucose amino acid meal in all groups. This increase in albumin synthesis accounted for 28% of the increase in whole body protein synthesis associated with feeding and for 24, 22, and 14% in the prednisone, rhGH, and combined treatment groups, respectively. These data suggest that the stimulation of albumin synthesis observed during feeding prevents irreversible oxidative losses of a significant fraction of ingested essential amino acids and may serve as a vehicle to capture excess dietary amino acids and transport them to peripheral tissues to sustain local protein synthesis.

scholarly journals Splanchnic-bed transfers of amino acids in sheep blood and plasma, as monitored through use of a multiple U-13C-labelled amino acid mixture

1996 ◽  
Vol 75 (2) ◽  
pp. 217-235 ◽  
Author(s):  
G. E. Lobley ◽  
A. Connell ◽  
D. K. Revell ◽  
B. J. Bequette ◽  
D. S. Brown ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Gas Chromatography Mass Spectrometry ◽  
Acid Mixture ◽  
Body Protein ◽  
Hydrolysis Of

AbstractThe response in whole-body and splanchnic tissue mass and isotope amino acid transfers in both plasma and blood has been studied in sheep offered 800 g lucerne (Medicago sutiva) pellets/d. Amino acid mass transfers were quantified over a 4 h period,by arterio-venous procedures, across the portal-drained viscera (PDV) and liver on day 5 of an intravenous infusion of either vehicle or the methylated products, choline (0.5 g/d) plus creatine (10 g/d). Isotopic movements were monitored over the same period during a 10 h infusion of a mixture of U-13C-labelled amino acids obtained from hydrolysis of labelled algal cells. Sixteen amino acids were monitored by gas chromatography-mass spectrometry, with thirteen of these analysed within a single chromatographic analysis. Except for methionine, which is discussed in a previous paper, no significant effects of choline plus creatine infusion were observed on any of the variables reported. Whole-body protein irreversible-loss rates ranged from 158 to 245 g/d for the essential amino acids, based on the relative enrichments (dilution of the U-13C molecules by those unlabelled) of free amino acids in arterial plasma, and 206-519 g/d, when blood free amino acid relative enrichments were used for the calculations. Closer agreement was obtained between lysine, threonine, phenylalanine and the branched-chain amino acids. Plasma relative enrichments always exceeded those in blood (P < 0.001), possibly due to hydrolysis of peptides or degradation of protein within the erythrocyte or slow equilibration between plasma and the erythrocyte. Net absorbed amino acids across the PDV were carried predominantly in the plasma. Little evidence was obtained of any major and general involvement of the erythrocytes in the transport of free amino acids from the liver. Net isotope movements also supported these findings. Estimates of protein synthesis rates across the PDV tissues from [U-13C] leucine kinetics showed good agreement with previous values obtained with single-labelled leucine. Variable rates were obtained between the essential amino acids, probably due to different intracellular dilutions. Isotope dilution across the liver was small and could be attributed predominantly to uni-directional transfer from extracellular sources into the hepatocytes and this probably dominates the turnover of the intracellular hepatic amino acid pools.

Whole body protein synthesis: studies with different amino acids in the rat

1989 ◽  
Vol 257 (5) ◽  
pp. E639-E646 ◽  
Author(s):  
C. Obled ◽  
F. Barre ◽  
D. J. Millward ◽  
M. Arnal
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Turnover ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Body Protein ◽  
Tissue Specific ◽  
Dose Method ◽  
Infusion Method

These studies were undertaken to determine to what extent constant infusion measurements and plasma sampling could provide sensible answers for rates of whole body protein turnover and also which amino acid would be the most representative probe of whole body protein turnover. Whole body protein synthesis rates were estimated in 70-g rats with L-[U-14C]threonine, L-[U-14C]lysine, L-[U-14C]tyrosine, L-[U-14C]phenylalanine, and L-[1-14C]leucine by either simultaneous tracer infusion of four amino acids or by injections of large quantities of 14C-labeled amino acids. In the infusion experiment, indirect estimates of whole body protein turnover based on free amino acid specific radioactivity and stochastic modeling were compared with direct measurement of the incorporation of the tracer into proteins. These two methods of analysis provided similar results for each amino acid, although in each case fractional synthesis rates were lower (by between 26 and 63%) when calculations were based on plasma rather than tissue specific radioactivity. With the flooding-dose method, whole body fractional protein synthesis rates were 41.4, 25.6, 31.1, and 31.4% with threonine, lysine, phenylalanine, and leucine, respectively. These values were similar to those obtained by the continuous infusion method using tissue specific radioactivity for threonine and lysine. For leucine, however, the flooding-dose method provided an intermediate value between the two estimates derived either from the plasma or the tissue specific radioactivity in the infusion method.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino acid requirements of the growing meat rabbit 2. Comparative growth performance on practical diets of equal lysine concentration but decreasing levels of other amino acids

1988 ◽  
Vol 47 (2) ◽  
pp. 303-310 ◽  
Author(s):  
W. H. Schultze ◽  
W. C. Smith ◽  
P. J. Moughan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Growth Performance ◽  
Crude Protein ◽  
Regression Line ◽  
National Research Council ◽  
Essential Amino Acids ◽  
Whole Body ◽  
Asymptotic Model ◽  
Amino Acid Requirement

ABSTRACTOver a 40-day period nine rabbits were each given one of nine isocaloric diets with progressively reduced amounts of crude protein (159 to 97 g/kg) but a fixed level of lysine; the latter was slightly below the higher of the National Research Council (NRC, 1977) and Societe de Chime Organique et Biologique (AEC, 1978) recommendations. The proportion of each other essential amino acid in the diet of highest crude protein concentration was close to a balance derived from the higher of each independently determined amino acid requirement given by NRC (1977) and AEC (1978), while the proportions in the two diets of lowest crude protein level were below those in a theoretical amino acid balance based on rabbit whole-body tissue composition. When an intersecting linear regression line model was fitted to growth performance data over the period, performance was found to be similar on the first six diets (159 to 123 g crude protein per kg) but further reductions in dietary protein were accompanied by a decline in growth rate and concomitant increase in food conversion ratio. Fitting of an asymptotic model to the data showed that growth performance first declined markedly between diets four and five (130 to 120 g crude protein per kg). These findings suggest that if a balance of essential amino acids relative to lysine, based on current amino acid recommendations, is adhered to in diet formulation for the growing rabbit, several of these amino acids will be in excess of requirement

Amino Acid and Protein Metabolism in Hospitalized Patients as Measured by l-[U-14C]Tyrosine and l-[1-14C]Leucine

1983 ◽  
Vol 65 (5) ◽  
pp. 499-505 ◽  
Author(s):  
Sukumar P. Desai ◽  
Lyle L. Moldawer ◽  
Bruce R. Bistrian ◽  
George L. Blackburn
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Chloride ◽  
Hospitalized Patients ◽  
Whole Body ◽  
Protein Kinetics ◽  
Body Protein ◽  
Sodium Chloride Solutions ◽  
Isotonic Sodium Chloride ◽  
Plasma Tyrosine

1. Plasma amino acid kinetics were determined in hospitalized patients receiving one of three intravenous solutions: isotonic amino acids, isotonic sodium chloride, or total parenteral nutrition. 2. Whole body amino acid appearance, oxidation and incorporation into protein were estimated with two different isotopically labelled amino acids: l-[1-14C]leucine and l-[U-14C]tyrosine. 3. A positive correlation was obtained between whole body amino acid appearance, oxidation and incorporation into protein with the two isotopically labelled amino acids. 4. Derivation of whole body protein kinetics with l-[U-14C]tyrosine consistently gave higher values than those obtained from l-[1-14C]leucine, presumably due in part to the contribution of phenylalanine hydroxylation to plasma tyrosine appearance. However, the percentages of amino acid appearance oxidized and used for protein synthesis were similar. 5. It can be concluded that estimates of whole body protein kinetics are qualitatively similar when measured with l-[U-14C]tyrosine and l-[1-14C]leucine in hospitalized patients receiving either isotonic sodium chloride solutions or balanced amino acid intakes.

Characterization of whole body compositional growth of male ducks during the twenty-nine day post-hatch period

2013 ◽  
Vol 93 (1) ◽  
pp. 113-122 ◽  
Author(s):  
A. P. Schinckel ◽  
M. E. Einstein ◽  
K. M. Ajuwon ◽  
O. Adeola
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dry Matter ◽  
The Body ◽  
Whole Body ◽  
Nutrient Requirements ◽  
Accretion Rates ◽  
Indispensable Amino Acids ◽  
Hatch Period

Schinckel, A. P., Einstein, M. E., Ajuwon, K. M. and Adeola, O. 2013. Characterization of whole body compositional growth of male ducks during the twenty-nine day post-hatch period. Can. J. Anim. Sci. 93: 113–122. Changes in whole body dry matter, lipid, ash, energy, crude protein, and amino acids were evaluated during a 29 d post-hatch period in White Pekin ducks. Drakes were assigned to slaughter 1, 8, 15, 22, or 29 d post-hatch with four replicates of four ducks per slaughter period. The body weight (BW) data were fitted to the Weibull function with the form:[Formula: see text]where BWit is the BW of the ith duck at t days of age and A, B, C, and IP are parameters. The value of IP, the inflection point, which minimized the residual SD, was 40 d. Values of A (8591 g, SE=190), B (42.87, SE=11.5), and C (1.7399, SE=0.050) resulted in an R 2 of 0.9836 and residual SD of 83.7 g. Allometric (Y=A BWB), linear-quadratic and exponential (Y=exp (b0+b1BW+b2 (BW)2) functions of BW were fitted to the chemical component and amino acid mass data. Dry matter percentage of the ducks increased (P<0.01) with age. The protein content of the dry matter decreased (P<0.01) from day 1 to day 8 (69 to 58.2%) and then increased to 60% by d 29. Concentrations of several amino acids were affected (P<0.05) by age. The predicted accretion rates of Lys, Trp, and Met relative to protein accretion increased as age increased. The predicted daily accretion rates for major indispensable amino acids increased rapidly the first 5 d post-hatch and subsequently increased but at a decreasing rate to day 29 post-hatch. The relative growth rates of chemical components and indispensable amino acids were affected by age indicating that the nutrient requirements of ducks differ from day 1 to day 29 post-hatch. Compositional growth and amino acid accretion data can be used to model the nutrient requirements of ducks.

Whole body protein kinetics in women: effect of pregnancy and IDDM during anabolic stimulation

2000 ◽  
Vol 279 (5) ◽  
pp. E978-E988 ◽  
Author(s):  
Paul G. Whittaker ◽  
Choy H. Lee ◽  
Roy Taylor
Keyword(s):  
Amino Acids ◽  
Type 1 Diabetes ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Metabolism ◽  
Whole Body ◽  
Protein Breakdown ◽  
Body Protein ◽  
In Pregnancy

The effects of pregnancy and type 1 diabetes [insulin-dependent diabetes mellitus (IDDM)] on protein metabolism are still uncertain. Therefore, six normal and five IDDM women were studied during and after pregnancy, using [13C]leucine and [2H5]phenylalanine with a hyperinsulinemic-euglycemic clamp and amino acid infusion. Fasting total plasma amino acids were lower in pregnancy in normal but not IDDM women (2,631 ± 427 vs. 2,057 ± 471 and 2,523 ± 430 vs. 2,500 ± 440 μmol/l, respectively). Whole body protein breakdown (leucine) increased in pregnancy [change in normal (ΔN) and IDDM women (ΔD) 0.59 ± 0.40 and 0.48 ± 0.26 g · kg−1 · day−1, both P < 0.001], whereas reductions in protein breakdown due to insulin/amino acids (ΔN −0.57 ± 0.19, ΔD −0.58 ± 0.20 g · kg−1 · day−1, both P < 0.001) were unaffected by pregnancy. Protein breakdown in IDDM women was not higher than normal, and neither pregnancy nor type 1 diabetes altered the insulin sensitivity of amino acid turnover. Nonoxidized leucine disposal (protein synthesis) increased in pregnancy (ΔN 0.67 ± 0.45, ΔD 0.64 ± 0.34 g · kg−1 · day−1, both P < 0.001). Pregnancy reduced the response of phenylalanine hydroxylation to insulin/amino acids in both groups (ΔN −1.14 ± 0.74, ΔD −1.12 ± 0.77 g · kg−1 · day−1, both P < 0.05). These alterations may enable amino acid conservation for protein synthesis and accretion in late pregnancy. Well-controlled type 1 diabetes caused no abnormalities in the regulation of basal or stimulated protein metabolism.

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