scholarly journals Amino acid oxidation by young pigs receiving diets with varying levels of sulphur amino acids

1983 ◽  
Vol 50 (2) ◽  
pp. 383-390 ◽  
Author(s):  
Kyu-Il Kim ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Choline Chloride ◽  
Milk Powder ◽  
Skim Milk ◽  
Essential Amino Acids ◽  
Acid Oxidation ◽  
Amino Acid Requirement

1. Piglets were weaned at 3 d of age and were introduced to liquid diets in which 400 g/kg protein was supplied as skim-milk powder and the balance as a mixture of free amino acids. The skim milk contributed 2·3 g methionine and 1·4 g cystine/kg diet; the experimental diets were made by supplementing these levels with free amino acids.2. The adequacy of the test level of the amino acid in the diet was assessed by measuring the oxidation of [1−14]phenylalanine as an indicator of the partition of the essential amino acids between incorporation into protein and degradation. Radioactivity recovered as carbon dioxide was used as a measure of catabolism.3. Addition of 0·2, 0·4, 0·7, 1·2 and 1·7 g L-methione/kg to a diet containing 5 g cystine and 3 g choline chloride/kg showed that phenylalanine catabolism was minimal for the diet with 2·7 g methionine/kg indicating that this is the dietary requirement for methionine to serve as a source of methionine residues for protein synthesis.4. Addition of D-methionine to produce a series of diets with graded levels of methionine showed that the D-isomer was less effective than the L-isomer in reducing phenylalanine catabolism: the addition of 0·8 g D-methionine/kg diet was needed to produce the same effect as 0·4 g L-methionine/kg diet showing that the replacement value of D-methionine for L-methionine was 50% in the young pig.5. To investigate the influence of cystine on methionine requirement, diets with varying levels of methionine and cystine were prepared. Oxidation of [U-14C]methionine was used as an indication of an excess of methionine, and the results showed that increasing the dietary methionine level above 3·0 g/kg in diets containing 1·4 g cystine/kg provided an excess of methionine for oxidation. This indicated a sulphur amino acid requirement of 4·4 g/kg, one-third of this being supplied as cystine.

scholarly journals Metabolism of heat-damaged proteins in the rat

1971 ◽  
Vol 26 (2) ◽  
pp. 311-322 ◽  
Author(s):  
J. E. Ford ◽  
C. Shorrock
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Total Amino Acid ◽  
Carbohydrate Complex ◽  
Urinary Peptide

1. Freeze-dried cod muscle and casein were subjected to various conditions of heat treat-ment. Diets containing the different products, or the unheated materials, were given to a group of four adult male rats during successive 48 h periods, and urine was collected during the second 24 h of each 48 h period. A further collection of urine was made from the rats after they had been given protein isolated from heated skim-milk powder. The content and amino acid composition of the ‘peptide’ and ‘free amino acids’ in the urines were determined.2. Heat damage to the cod-fillet protein increased the total urinary excretion of peptide-bound amino acids, from 18·6 to 48·8 µmol/rat.d. The composition of the peptide also changed, and in particular there was a marked increase in lysine, from 2·98 to 20·30 µmol %. Three amino acids - lysine, aspartic acid and glutamic acid - together comprised nearly 70 % of the total amino acid residues. There was a corresponding increase in urinary excretion of free amino acids, from 53·7 to I 14·4 µmol/rat.d. The combined losses of lysine in urinary peptide and free amino acids were 1·5 % of the total lysine ingested, as against 0·3 % for the unheated cod fillet.3. The effects of similar heat treatment of casein on the composition of the urinary peptide and free amino acids were less marked. There was no increase in total urinary peptide excretion and there was a smaller increase in the lysine content of the peptide.4. In urine of rats given protein isolated from heated skim-milk powder, the peptide hydro-lysate was rich in lysine and in furosine, which together comprised 41 mol % of the total amino acid composition. These compounds were presumably formed, together with a smaller quantity of pyridosine, from lysine-carbohydrate complex in the urine. It is probable that, as compared with free lysine, the lysine-carbohydrate complex was absorbed relatively in-efficiently from the rat intestine.5. The findings are discussed in relation to the wider question of the metabolism of the ‚unavailable peptide’ that is released in the course of digestion of heat-damaged protein.

Intracellular Free Amino Acids in Muscle Tissue of Patients with Chronic Uraemia: Effect of Peritoneal Dialysis and Infusion of Essential Amino Acids

1978 ◽  
Vol 54 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J. Bergström ◽  
P. Fürst ◽  
L.-O. Norée ◽  
E. Vinnars
Keyword(s):  
Amino Acids ◽  
Peritoneal Dialysis ◽  
Amino Acid ◽  
Muscle Tissue ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Chronic Uraemia ◽  
Muscle Water ◽  
Intracellular Concentrations

1. Free amino acids were determined in the plasma and in the muscle tissue of 14 patients with chronic uraemia; eight were not on dialysis and six were having regular peritoneal dialysis. The concentration of each amino acid in muscle water was calculated with the chloride method. 2. In both groups of patients there were low intracellular concentrations of threonine, valine, tyrosine and carnosine, and high glycine/valine and phenylalanine/tyrosine ratios. Both groups of patients had increased amounts of 1- and 3-methylhistidine in plasma and in muscle water. 3. The non-dialysed patients had low intracellular concentrations of lysine, and the dialysed patients had high intracellular concentrations of lysine, isoleucine, leucine and of some of the non-essential amino acids. 4. After peritoneal dialysis for 22 h, the plasma concentration of several amino acids decreased but the intracellular concentrations of most amino acids did not change significantly. 5. Intravenous administration of essential amino acids and histidine during the last 4 h of dialysis increased in muscle the total free amino acids, the ratio of essential to non-essential amino acids and the valine and phenylalanine concentrations. 6. The results demonstrated that the plasma and muscle concentrations of several amino acids are grossly abnormal in chronic uraemia. Non-dialysed and dialysed patients exhibit important differences, especially in the intracellular amino acid patterns. Infusion of essential amino acids may result in enhancement of 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.

scholarly journals Influence of dietary protein concentration on the oxidation of phenylalanine by the young pig

1986 ◽  
Vol 55 (3) ◽  
pp. 651-658 ◽  
Author(s):  
Ronald O. Ball ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
G Protein ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Crude Protein ◽  
Protein Concentration ◽  
Skim Milk ◽  
Intact Protein

1. Piglets were weaned at 3 d of age and reared to 2.5 kg on a liquid diet in which the protein was supplied by dried skim milk and a mixture of free amino acids. The oxidation of L-[l-14C]phenyIalanine was measured as an indication of the partition of amino acids between retention and catabolism in pigs (2.5 kg) offered meals containing vaned concentrations of crude protein (nitrogen x 6.25).2. The dietary protein concentration was varied either by increasing the inclusion of a mixture of free amino acids in a series of diets containing 100 g protein/kg from skim milk, or by increasing the level of inclusion of the skim milk in a series of diets containing the equivalent of 100 g protein/kg from the free amino acid mixture.3. The oxidation of phenylalanine was minimized by dietary protein concentrations of 240 and 258 g/kg for the diets containing increasing concentrations of free amino acids or skim milk respectively.4. These results show that a mixture of free amino acids is used more effectively than intact protein for promoting retention of essential amino acids.5. The recovery of radioactivity in expired carbon dioxide was inversely related to the recovery of radioactivity in liver tissue when the concentration of dietary crude protein was increased from deficient to adequate, demonstrating that the fractional oxidation of the indicator amino acid was inversely related to protein synthesis.

scholarly journals The effects of maternal protein restriction on the growth of the rat fetus and its amino acid supply

1999 ◽  
Vol 81 (3) ◽  
pp. 243-250 ◽  
Author(s):  
William D. Rees ◽  
Susan M. Hay ◽  
Viv Buchan ◽  
Christos Antipatis ◽  
Robert M. Palmer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
G Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Maternal Serum ◽  
Rat Fetus ◽  
Adult Disease ◽  
Low Protein

Maternal protein deficiency causes fetal growth retardation which has been associated with the programming of adult disease. The growth of the rat fetus was examined when the mothers were fed on diets containing 180, 90 and 60 g protein/kg. The numbers of fetuses were similar in animals fed on the 180 and 90 g protein/kg diets but the number was significantly reduced in the animals fed on the 60 g protein/kg diet. The fetuses carried by the mothers fed on the 90 g protein/kg diet were 7·5% heavier than those of mothers fed on 180 g protein/kg diet on day 19 of gestation, but by day 21 the situation was reversed and the fetuses in the protein-deficient mothers were 14% smaller. Analysis of the free amino acids in the maternal serum showed that on day 19 the diets containing 90 and 60 g protein/kg led to threonine concentrations that were reduced to 46 and 20% of those found in animals fed on the control (180 g/kg) diet. The other essential amino acids were unchanged, except for a small decrease in the branched-chain amino acids in animals fed on the 60 g protein/kg diet. Both low-protein diets significantly increased the concentrations of glutamic acid+glutamine and glycine in the maternal serum. On day 21 the maternal serum threonine levels were still reduced by about one third in the group fed on the 90 g protein/kg diet. Dietary protein content had no effect on serum threonine concentrations in non-pregnant animals. Analysis of the total free amino acids in the fetuses on day 19 showed that feeding the mother on a low-protein diet did not change amino acid concentrations apart from a decrease in threonine concentrations to 45 and 26% of the control values at 90 and 60 g protein/kg respectively. The results suggest that threonine is of particular importance to the protein-deficient mother and her fetuses. Possible mechanisms for the decrease in free threonine in both mother and fetuses and the consequences of the change in amino acid metabolism are discussed.

scholarly journals Determination of amino acid requirements of young pigs using an indicator amino acid

1983 ◽  
Vol 50 (2) ◽  
pp. 369-382 ◽  
Author(s):  
Kyu-Il Kim ◽  
Ian McMillan ◽  
Henry S. Bayley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Essential Amino Acid ◽  
Free Amino ◽  
Skim Milk ◽  
Linear Increase ◽  
Deficient Diet ◽  
Direct Estimate ◽  
Phenylalanine Level

1. Mixtures of skim milk and free amino acids were compared as diets for pigs which would allow manipulation of dietary amino acid levels. Piglets gained 208 g/d between 3 and 14 d of age on the skim-milk diet, but replacement of 600 g/kg of the dietary nitrogen with free amino acids reduced growth rate to 148 g/d.2. Supplementation of a lysine-deficient diet with lysine reduced the catabolism of [14C]phenylalanine showing that phenylalanine catabolism could be used as an indicator of the adequacy of diet with respect to another essential amino acid.3. The dietary level of phenylalanine which would provide an excess for catabolism by the piglet was estimated directly by measuring the influence of dietary phenylalanine level on [14C]phenylalanine oxidation. Reduction of the dietary phenylalanine level below 7 g/kg had no effect on phenylalanine oxidation, whereas increasing the dietary phenylalanine level above 7 g/kg resulted in a linear increase in phenylalanine oxidation.4. An indirect estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]phenylalanine oxidation. In diets containing more than 4 g histidine/kg, phenylalanine oxidation was minimal. In diets containing less than 4 g histidine/kg, [14C]phenylalanine oxidation increased as the level of dietary histidine was reduced. This showed that the utilization of the essential amino acid phenylalanine, for protein synthesis, was not limited by histidine supply in diets containing more than 4 g histidine/kg.5. A direct estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]histidine oxidation. Diets with more than 4 g histidine/kg contained an excess which was catabolized: there was a linear increase in histidine oxidation in response to dietary histidine levels greater than 4 g/kg. This confirmed the previous indirect estimate of histidine requirement.

scholarly journals Changes in the plasma concentrations of free amino acids in relation to egg formation in the hen

1970 ◽  
Vol 24 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
T. G. Taylor ◽  
J. J. Waring ◽  
R. K. Scougall
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Egg Production ◽  
Nutritive Value ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Egg Formation ◽  
Amino Acid Requirements

1. The changes occurring in the free amino acids of the plasma of laying hens in relation to egg formation have been investigated in fed and starved hens in three experiments, each with eight birds.2. The mean concentrations of most amino acids and of the totals were higher at night than in the morning.3. In general, egg formation was associated with increases in the concentrations of non- essential and decreases in the concentrations of essential amino acids. Cystine and glutamic acid tended to behave like the essential amino acids.4. After 40 h starvation seven amino acids, particularly serine, histidine and lysine, in- creased in concentration and only three, proline, ornithine and arginine, decreased significantly.5. When eight cocks were injected with oestrogen most of the amino acids increased in con-centration. The essential amino acids (with the exception of phenylalanine), serine, proline, cystine and ornithine showed the greatest increases.6. The results are discussed in relation to the possibility that the voluntary food intake of hens may be influenced by changes in the plasma levels of one or more essential amino acids associated with the synthesis of egg albumen. Arginine appeared to be the only amino acid that might possibly fulfil this role.7. It was concluded that investigations of changes in the free amino acids of hen plasma are unlikely to provide a useful approach to a study of the amino acid requirements or the nutritive value of particular proteins for egg production.

scholarly journals AMINO ACID PROFILE OF PHASEOLUS VULGARIS PODS AND DRY EXTRACT PREPARED OF THEM

2019 ◽  
pp. 40-48
Author(s):  
L. V. Vronska ◽  
A. Ye. Demyd
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Phaseolus Vulgaris ◽  
Free Amino Acids ◽  
Free Amino ◽  
Total Content ◽  
Essential Amino Acids ◽  
Amino Acid Profile ◽  
Raw Material ◽  
Dry Extract

The aim of the research was to study the amino acid profile of the phaseolus vulgaris pods and extract prepared of them. Materials and methods. Five samples of raw material of phaseolus vulgaris pods (erect herbaceous bushes varieties with white seeds) were collected in the Ternopil and Volyn regions, dry extract of phaseolus vulgaris pods was obtained according to previously developed technology. The study of amino acid composition of the raw materials of phaseolus vulgaris pods and extract prepared of them was carried out using a thin-layer chromatography (TLC) and a high-performance liquid chromatography (HPLC). Results and discussion. The better separation of amino acids in TLC-research of the raw material of phaseolus vulgaris pods was observed in the system of solvents isopropanol - formic acid - water (40: 2: 10). As a result of the study, aspartic and glutamic acids, glycine, valine, tyrosine and leucine were identified. The amino acid profile of the studied samples of raw material is quite homogeneous in composition: 7 essential amino acids (histidine, threonine, valine, methionine, phenylalanine, isoleucine and leucine) and 8 non-essential amino acids (aspartic and glutamic acids, arginine, serine, glycine, alanine, tyrosine and proline); lysine was found among the bound amino acids in the 4th sample of raw material. Proline predominates in all samples of raw materials among free amino acids. Among the bound amino acids the content of glutamic acid, which is the product of the glutamine hydrolysis, is the highest. The content of glycine, serine and alanine is also high. Among the essential amino acids, leucine, phenylalanine, histidine, threonine, isoleucine, valine were determined in content descending order. The quantitative determination of amino acids in the extract of phaseolus vulgaris pods proved that the content of proline was the highest (12.47 mg / g); the content of some compounds was also high: aspartic (5.41 mg / g) and glutamic (3.41 mg / g) acids, arginine (5.10 mg / g; both in free and bound forms), glycine (1.02 mg / g) and serine (1.04 mg / g). Among the essential amino acids in the extract, the amount of valine (0.80 mg / g), phenylalanine (0.67 mg / g), threonine (0.66 mg / g), leucine (0.63 mg / g) and isoleucine (0.58 mg / g) was a little different. The total content of amino acids in the extract was 3.2%. Conclusions. 1. The amino acid profile of five samples of phaseolus vulgaris pods was studied by the HPLC method. It has been established that the composition is quite homogeneous, and the total content varies within 0.7-1.1%. 2. In the dry extract of phaseolus vulgaris pods the content of 5 essential and 7 non-essential amino acids has been determined. The content of free amino acids in the extract is 0.52%; the total content of free and bound amino acids is 3.2%. 3. When studying the stability and establishing the shelf life of the dry extract of phaseolus vulgaris pods, it is necessary to take into account the presence of free amino acids and protein substances.  

PARTIAL REPLACEMENT OF SKIM MILK WITH FREE AMINO ACIDS IN DIETS FOR THE PIGLET

1984 ◽  
Vol 64 (4) ◽  
pp. 1019-1022 ◽  
Author(s):  
R. O. BALL ◽  
K. I. KIM ◽  
H. S. BAYLEY
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Control Diet ◽  
Skim Milk ◽  
Partial Replacement ◽  
Synthetic Diet ◽  
Acid Diet ◽  
Amino Acid Requirements

A semi-synthetic diet in which 60% of the nitrogen from dried skim milk was replaced with a mixture of free amino acids supported gains of 236 g/day between 3 and 18 days of age, as compared with a gain of 282 g/day for a control diet in which skim milk provided all the protein. Neutralizing the acidity of the free amino acid diet increased its palatability. All of the indispensible amino acids may be made deficient in the experimental diet, thus providing the opportunity to evaluate the amino acid requirements of the piglet. Key words: Piglets, growth, amino acids, semi-synthetic diet

Effect of a Test Meal, without and with Protein, on Muscle and Plasma Free Amino Acids

1990 ◽  
Vol 79 (4) ◽  
pp. 331-337 ◽  
Author(s):  
J. Bergström ◽  
P. Fürst ◽  
E. Vinnars
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Free Amino Acids ◽  
Free Amino ◽  
Essential Amino Acids ◽  
Muscle Concentration ◽  
Protein Rich

1. The effect of a protein-free meal and a protein-rich meal on the concentration of free amino acids in plasma and muscle tissue was studied in eight healthy subjects. The energy content of the protein-free meal was 3800 kJ. The protein-rich meal was identical in composition except that 50 g of bovine serum albumin was added. Plasma and samples from the quadriceps femoris muscle (percutaneous muscle biopsy) for amino acid determination were collection before and at 1, 3, 5 and 7 h after the meal. 2. After the protein-free meal the concentrations of most essential amino acids and of some non-essential amino acids in plasma decreased continuously below basal levels at 5–7 h. The muscle concentration of essential amino acids fell too, reaching its nadir 3–5 h after the meal. The decrease in plasma amino acid concentration was smaller than the decrease in muscle concentration for all essential amino acids except phenylalanine. 3. The concentrations of most amino acids in plasma increased transiently 1 and 3 h after the protein-rich meal; histidine and several non-essential amino acids fell below the basal levels at 5–7 h after the meal. In muscle, threonine, valine, leucine, lysine and alanine were increased at 1 and 3 h after the protein-rich meal; isoleucine, serine and glycine fell below the basal level after 5 and 7 h. For the essential amino acids except threonine and lysine, the increase in plasma concentration was greater than the increase in muscle concentration. 4. Correlations were observed between the relative content of the essential amino acids in the bovine serum albumin and the increase in concentration of these amino acids in plasma and muscle. Methionine and isoleucine, which had the lowest content in bovine serum albumin, fell below basal levels in plasma and (for isoleucine) in muscle 5–7 h after the meal, suggesting that these two amino acids might have been limiting for protein synthesis. 5. Amino acid analysis in plasma and muscle samples taken postprandially should be evaluated with caution considering the strong influence of meal composition on plasma and muscle free amino acid profiles.

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