The effect of dietary protein quality on free amino acids in plasma, muscle and liver of growing chickens

1993 ◽  
Vol 57 (2) ◽  
pp. 309-318 ◽  
Author(s):  
I. Fernández-Figares ◽  
M. Lachica ◽  
L. Pérez ◽  
R. Nieto ◽  
J. F. Aguilera ◽  
...  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Quality ◽  
Sole Source ◽  
Metabolizable Energy ◽  
Low Protein ◽  
Protein Diets

AbstractFree amino acid (AA) levels in plasma, muscle and liver were measured in growing chickens given either high or low protein diets varying in quality. In experiment 1, they were force-fed once a day (09.00 h), for 4 days, at about 1·5 × M level, a nitrogen-free (NF) diet and then, on day 5, they were given either diet NF or isoenergetic (13·1 kj metabolizable energy (ME) per g dry matter (DM)) and isonitrogenous high protein diets (200 g crude protein (CP) per kg) based on casein (C), lupin (L), soya bean (SB), faba bean (FB), field pea (FP), vetch (V) or bitter vetch (B) as the sole source of protein. In experiment 2, chickens were force-fed twice a day (09.00 h and 18.00 h), for 3 days, at about 1·9 × M level, with four isoenergetic (13·1 k) ME per kg DM) and isonitrogenous low protein diets (120 g CP per kg) based on SB, FP, V or B as the sole source of protein. On days 5 (experiment 1) and 4 (experiment 2) samples of plasma, muscle and liver were taken for AA analysis over 3 to 4h after morning meal.In general, within experiments, no significant differences in AA concentrations in plasma, muscle or liver among diets were found. However, there was a qualitative but not a quantitative agreement between the AA abundance in tissues and the AA rank of dietary protein. Moreover, when pooling data from experiments 1 and 2, significant regressions were found between the levels of threonine, aspartic acid, glutamic acid, glycine and proline in plasma, of lysine, alanine, glutamic acid, glycine and proline in muscle or that of proline in liver and the corresponding amounts ingested with the different diets. Under the conditions of these experiments, however, it was not possible to establish conclusively a direct relationship between the level of free amino acids in tissues and dietary protein quality.

Effects of dietary protein and potassium contents on plasma urea nitrogen and amino acids in relation to performance of swine

1996 ◽  
Vol 76 (3) ◽  
pp. 351-355 ◽  
Author(s):  
Yongjiu Cai ◽  
Richard C. Ewan ◽  
Dean R. Zimmerman
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Diet ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Protein Diets ◽  
Potassium Addition

Ninty-six 51 kg-pigs were used to determine effects of dietary protein and potassium levels on concentrations of plasma urea nitrogen (PUN) and free amino acids. Pigs were fed four diets containing 13 or 15% of protein and 0 or 0.4% of potassium addition. Gilts took more days to reach an average weight of 110 kg with lower PUN and less backfat than barrows (P < 0.05), but sex did not affect concentrations of plasma free amino acids (P > 0.10). The pigs fed 15% protein diets had higher PUN (P < 0.01) and plasma threonine and isoleucine (P < 0.05), but lower (P < 0.05) plasma lysine, glutamic acid and glycine than pigs fed 13% protein diets. The 0.4% potassium addition resulted in a tendency to increase PUN (P = 0.06) and a decrease in concentrations of plasma alanine, glutamic acid and glycine (P < 0.05). There was an interaction between protein and potassium treatments (P < 0.05) in which plasma lysine concentration decreased with potassium addition to the 13% protein diet but increased with potassium addition to the 15% protein diet. The results indicate that lower PUN concentrations in gilts were associated with improved efficiency of deposition of dietary nitrogen, resulting in improved carcass grade compared with barrows receiving the same dietary treatments. Key words: Plasma urea nitrogen, free amino acids, protein, potassium, pigs

Milk Protein Quantity and Quality in Low-Birth-Weight Infants: II. Effects on Selected Aliphatic Amino Acids in Plasma and Urine

PEDIATRICS ◽  
1977 ◽  
Vol 59 (3) ◽  
pp. 407-422 ◽  
Author(s):  
David K. Rassin ◽  
Gerald E. Gaull ◽  
Kirsti Heinonen ◽  
Niels C. R. Räihäa
Keyword(s):  
Amino Acids ◽  
Birth Weight ◽  
Low Birth Weight ◽  
Human Milk ◽  
Free Amino Acids ◽  
Free Amino ◽  
Plasma Concentrations ◽  
Low Birth Weight Infants ◽  
Low Protein ◽  
Protein Diets

The optimal quantity and quality of protein for low-birth-weight infants is undefined. In this study, 106 well, appropriate-for-gestational-age, low-birth-weight infants weighing 2,100 gm or less were divided into three gestational age groups and assigned randomly within each age group to one of five feeding regimens: pooled human milk; formula 1 (protein content, 1.5 gm/100 ml, 60 parts bovine whey proteins to 40 parts bovine caseins); formula 2 (3.0 gm/100 ml, 60:40); formula 3 (1.5 gm/100 ml, 18:82); and formula 4 (3.0 gm/100 ml, 18:82). The concentrations of the free amino acids in the plasma and urine of these infants were determined. The plasma concentrations of free amino acids were generally far greater in the infants fed the 3.0-gm/100 ml protein diets than they were in the infants fed pooled human milk. The plasma concentrations of free amino acids of the infants fed the 1.5-gm/100 ml protein diets were intermediate. In general, the concentrations of the free amino acids in the plasma of the infants fed the 3.0-gm/100 ml caseinpredominant formula (F4) were furthest from those fed pooled human milk. Glutamate showed the highest plasma amino acid concentrations in infants fed both the high- and low-protein casein-predominant formulas. This was true despite the fact that the intake of glutamate on the high-protein, whey-predominant formula was twice that on the low-protein, casein-predominant formula. The differences between groups in the essential amino acids in plasma were generally greater than those of the nonessential amino acids. The concentrations of amino acids in the urine tended to parallel those of the plasma.

Dietary regulation of intestinal transport of the dipeptide carnosine

1988 ◽  
Vol 255 (2) ◽  
pp. G143-G150 ◽  
Author(s):  
R. P. Ferraris ◽  
J. Diamond ◽  
W. W. Kwan
Keyword(s):  
Amino Acids ◽  
Cell Surface ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Intestinal Transport ◽  
Dietary Regulation ◽  
Dietary Protein Level ◽  
Low Protein ◽  
Hydrolysis Of

Uptake of the dipeptide L-carnosine was measured in everted intestinal sleeves of mice whose dietary protein level or else proportion of protein in the form of free amino acids was varied experimentally. Carnosine uptake was highest in the jejunum, regardless of ration. Compared with a low-protein (18%) ration, a high-protein (72%) ration stimulated carnosine uptake by 30-70% in duodenum and jejunum (but not in ileum). This stimulation was observed even in the presence of peptidase inhibitors that inhibit cell surface hydrolysis of dipeptides. Measured carnosine hydrolysis was low or negligible. Carnosine uptake was the same in mice fed 54% unhydrolyzed casein, 54% partly hydrolyzed casein, and 54% free amino acids formulated so as to stimulate a complete hydrolysate of casein. Thus carnosine uptake is regulated by dietary levels of amino acids, peptides, and proteins, all of which seem equally effective at inducing carnosine transporters.

scholarly journals Effect of low protein diets on free amino acids in plasma of young men: Effect of wheat gluten diet.

1979 ◽  
Vol 25 (5) ◽  
pp. 427-439 ◽  
Author(s):  
Yoshiaki FUJITA ◽  
Takashi YAMAMOTO ◽  
Toru RIKIMARU ◽  
Goro INOUE
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Wheat Gluten ◽  
Young Men ◽  
Low Protein ◽  
Protein Diets

INFLUENCE OF DIETARY ANTIBIOTICS ON NITROGEN, AMINO ACID AND ENERGY DIGESTION BY RATS AND ADULT ROOSTERS

1982 ◽  
Vol 62 (2) ◽  
pp. 537-545 ◽  
Author(s):  
L. D. CAMPBELL ◽  
B. O. EGGUM ◽  
J. WOLSTRUP
Keyword(s):  
Amino Acids ◽  
Dietary Protein ◽  
Protein Quality ◽  
Positive Influence ◽  
Metabolizable Energy ◽  
Biological Value ◽  
Key Words Antibiotics ◽  
True Digestibility ◽  
Neomycin Sulfate ◽  
Net Protein

The influence of antibiotics (a 2:1 mixture of bacitracin and neomycin sulfate at 0.7% of the diet) on the availability of energy from barley-fishmeal-based diets was assessed using rats and adult roosters. Changes in estimates of protein quality, as influenced by dietary antibiotics were also determined in the study with rats. Gut biomass content was estimated by measuring the content of adenosine triphosphate (ATP) in gut samples of rats and fresh excreta samples of roosters. Antibiotic addition to the diet significantly (P < 0.01) reduced apparent digestible energy in rats and tended to reduce the true metabolizable energy measured with roosters. Biological value of the protein for rats was increased significantly (P < 0.01) by antibiotics as were net protein utilization values even though true digestibility of protein was decreased significantly (P < 0.01). The availability of some amino acids (e.g. histidine) showed a marked depression (12.1 percentage units) when antibiotics were added to the diet while others were not influenced (e.g. lysine and methionine) or markedly (7.6 percentage units) increased (e.g. alanine). The extent of microbial activity, which was shown to be markedly higher in the hindgut of rats fed no antibiotics as compared to rats fed antibiotics, may have contributed to the positive influence of antibiotic feeding on biological value of dietary protein and to the changes noted in excretion of amino acids by rats and roosters. Key words: Antibiotics, Nitrogen, amino acids, energy, rats, rosters

scholarly journals Utilization in vivo of glucose and volatile fatty acids by sheep brain for the synthesis of acidic amino acids

1966 ◽  
Vol 101 (3) ◽  
pp. 591-597 ◽  
Author(s):  
R M O'Neal ◽  
R E Koeppe ◽  
E I Williams
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Sheep Brain ◽  
The Brain

1. Free glutamic acid, aspartic acid, glutamic acid from glutamine and, in some instances, the glutamic acid from glutathione and the aspartic acid from N-acetyl-aspartic acid were isolated from the brains of sheep and assayed for radioactivity after intravenous injection of [2-(14)C]glucose, [1-(14)C]acetate, [1-(14)C]butyrate or [2-(14)C]propionate. These brain components were also isolated and analysed from rats that had been given [2-(14)C]propionate. The results indicate that, as in rat brain, glucose is by far the best precursor of the free amino acids of sheep brain. 2. Degradation of the glutamate of brain yielded labelling patterns consistent with the proposal that the major route of pyruvate metabolism in brain is via acetyl-CoA, and that the short-chain fatty acids enter the brain without prior metabolism by other tissue and are metabolized in brain via the tricarboxylic acid cycle. 3. When labelled glucose was used as a precursor, glutamate always had a higher specific activity than glutamine; when labelled fatty acids were used, the reverse was true. These findings add support and complexity to the concept of the metabolic; compartmentation' of the free amino acids of brain. 4. The results from experiments with labelled propionate strongly suggest that brain metabolizes propionate via succinate and that this metabolic route may be a limited but important source of dicarboxylic acids in the brain.

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