Concurrent and carryover effects of feeding blends of protein and amino acids in high-protein diets with different concentrations of forage fiber to fresh cows. 1. Production and blood metabolites

2021 ◽  
Author(s):  
A.W. Tebbe ◽  
W.P. Weiss
Keyword(s):  
Amino Acids ◽  
High Protein ◽  
Blood Metabolites ◽  
Carryover Effects ◽  
High Protein Diets ◽  
Protein Diets

Dietary protein paradox: decrease of amino acid availability induced by high-protein diets

1993 ◽  
Vol 264 (6) ◽  
pp. G1057-G1065 ◽  
Author(s):  
C. Moundras ◽  
C. Remesy ◽  
C. Demigne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dietary Protein ◽  
High Protein ◽  
Glutamine Metabolism ◽  
Metabolic Adaptation ◽  
Casein Diet ◽  
Serine Dehydratase ◽  
High Protein Diets ◽  
Protein Diets

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Stimulation of amino acid transport into liver cells from rats adapted to a high-protein diet

1982 ◽  
Vol 206 (1) ◽  
pp. 13-18 ◽  
Author(s):  
P Fafournoux ◽  
C Rémésy ◽  
C Demigné
Keyword(s):  
Amino Acids ◽  
Decisive Role ◽  
High Protein Diet ◽  
Isolated Hepatocytes ◽  
Hepatic Uptake ◽  
High Protein ◽  
Protein Diet ◽  
High Protein Diets ◽  
Protein Diets

After adaptation of rats to a 90%-casein diet, hepatic uptake of alanine is strikingly increased in vivo, with concomitant appearance of a concentration of favourable for uptake. With a high-protein diet, uptake of 2-aminoisobutyrate by isolated hepatocytes in the presence of various concentrations of substrates suggested induction of the A system (high-affinity system), whose emergence has been reported during starvation or after glucagon treatment. The other system (ASC, L) were characterized: induction processes only affected the A system. Dibutyryl cyclic AMP addition resulted in an increase in 2-aminoisobutyrate transport at low substrate concentration, the response being greater after adaptation to a high-protein diet. Evidence is presented suggesting that the increased uptake of amino acids by the liver of rats fed on high-protein diets is obtained by developing favourable gradients and enhancing transport capacities. These adaptations allow sufficient amounts of amino acids to enter the liver, where accelerated metabolism plays a decisive role.

Familial Hypoglycemia Precipitated by Amino Acids

PEDIATRICS ◽  
1956 ◽  
Vol 18 (2) ◽  
pp. 192-192
Keyword(s):  
Amino Acids ◽  
Isovaleric Acid ◽  
High Protein ◽  
Dramatic Effect ◽  
Low Protein ◽  
Normal Individuals ◽  
True Blood ◽  
Protein Feeding ◽  
High Protein Diets ◽  
Protein Diets

This paper reports three cases of hypoglycemia in one family and an unrelated case in which profound hypoglycemia and convulsions were produced by the administration of proteins or amino acids. The patients described are similar to the group which have been reported in the literature as infantile idiopathic hypoglycemosis. Casein, leucine, and isovaleric acid fed to the patients caused a marked fall in the fasting concentration of true blood sugar. High protein feeding led to more convulsions and lower concentrations of sugar in the blood than did a low protein diet. Leucine had the most dramatic effect. Casein and leucine did not produce a fall in the sugar in the blood in normal individuals. The literature on metabolic interrelations between amino acids and carbohydrates and the concentration of sugar in the blood is reviewed. The mode of action of amino acids in depressing the concentration of sugar in the blood in infants with spontaneous hypoglycemia is considered and several hypotheses proposed. This paper is of unusual interest and of great importance for the treatment of infants with spontaneous idiopathic hypoglycemia. It is suggested that in this particular type of hypoglycemia high protein diets should be avoided. Small amounts of carbohydrate may be given 30 to 40 minutes after the ingestion of a meal containing protein to offset the effect of protein in lowering the concentration of sugar in the blood.

scholarly journals Parsing the life-shortening effects of dietary protein: effects of individual amino acids

2017 ◽  
Vol 284 (1846) ◽  
pp. 20162052 ◽  
Author(s):  
Sara Arganda ◽  
Sofia Bouchebti ◽  
Sepideh Bazazi ◽  
Sophie Le Hesran ◽  
Camille Puga ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Protein Diet ◽  
Amino Acid Profile ◽  
High Protein ◽  
Regulate Food Intake ◽  
High Protein Diets ◽  
Protein Diets

High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins; (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves; (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins; and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome; surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan.

scholarly journals THE EFFECT OF HIGH PROTEIN DIETS ON THE KIDNEYS OF RATS

1926 ◽  
Vol 67 (1) ◽  
pp. 101-107
Author(s):  
Henry Jackson ◽  
Margaret D. Riggs
Keyword(s):  
High Protein ◽  
High Protein Diets ◽  
Protein Diets
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