Effect of Prior High Protein Intake on Food Intake, Serine Dehydratase Activity and Plasma Amino Acids of Rats Fed Amino Acid-imbalanced Diets

1969 ◽  
Vol 97 (4) ◽  
pp. 463-474 ◽  
Author(s):  
Helen L. Anderson ◽  
N. J. Benevenga ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Protein Intake ◽  
High Protein ◽  
Plasma Amino Acids ◽  
High Protein Intake ◽  
Serine Dehydratase ◽  
Dehydratase Activity

High Protein Intake during Continuous Hemodiafiltration: Impact on Amino Acids and Nitrogen Balance

2002 ◽  
Vol 25 (4) ◽  
pp. 261-268 ◽  
Author(s):  
R. Bellomo ◽  
H. K. Tan ◽  
S. Bhonagiri ◽  
I. Gopal ◽  
J. Seacombe ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Balance ◽  
Protein Intake ◽  
Protein Supplementation ◽  
High Protein ◽  
Total Serum ◽  
Amino Acid Supplementation ◽  
Continuous Hemodiafiltration ◽  
High Protein Intake

Aims To study the effect of combined continuous veno-venous hemodiafiltration (CVVHDF) and high (2.5 g/kg/day) parenteral amino acid supplementation on nitrogen balance, amino acid losses and azotemic control in a cohort of patients with severe acute renal failure (ARF). Methods We administered 2.5 grams/kg/day of amino acids intravenously to seven critically ill patients with ARF. We obtained paired blood and ultrafiltrate (UF) samples (n=20) and calculated amino acid clearances and losses, nitrogen balance, protein catabolic rate and total nitrogen losses. Results The median total serum amino acid concentration was high at 5.2 mmol/L with particularly high concentrations of ornithine, lysine, and phenylalanine, but a low level of histidine. The median overall amino acid clearance was 18.6 ml/min (range: 12 to 29 ml/min). UF losses as percentage of administered dose were high for tyrosine (53.6 %) but low for methionine (3.0 %) and arginine (2.3 %). A positive nitrogen balance was achieved in 7 (35%) of the 20 study days with an overall median nitrogen balance of -1.8 g/day. Urea levels were maintained at a median of 26.6 mmol/L. Conclusions High protein intake increases the serum concentrations of most amino acids. Such protein supplementation, when coupled with CVVHDF, achieves a slightly negative overall nitrogen balance in extremely catabolic patients while still allowing adequate azotemic control.

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)

Food Intake Regulation: Amino Acid Toxicity and Changes in Rat Brain and Plasma Amino Acids

1973 ◽  
Vol 103 (4) ◽  
pp. 608-617 ◽  
Author(s):  
Y. Peng ◽  
J. Gubin ◽  
A. E. Harper ◽  
M. G. Vavich ◽  
A. R. Kemmerer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Rat Brain ◽  
Plasma Amino Acids ◽  
Food Intake Regulation ◽  
Acid Toxicity ◽  
Intake Regulation

Amino acid imbalance protein intake, and changes in rat brain and plasma amino acids

1972 ◽  
Vol 223 (6) ◽  
pp. 1497-1497
Author(s):  
Y. Peng ◽  
J. K. Tews ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rat Brain ◽  
Protein Intake ◽  
Plasma Amino Acids ◽  
Amino Acid Imbalance

Page 314: Y. Peng, J. K. Tews, and A. E. Harper. "Amino acid imbalance protein intake, and changes in rat brain and plasma amino acids." Page 317, Fig. 5: the top section should carry the heading "HISTIDINE IMBALANCE (liver)."

Influence of protein and amino acids on food intake in the rat

1965 ◽  
Vol 209 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Ronald M. Krauss ◽  
Jean Mayer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Food Intake ◽  
Protein Intake ◽  
Safety Valve ◽  
Constant Amount ◽  
Catabolic Activity ◽  
Low Protein ◽  
Amino Acid Intake ◽  
Hypothalamic Mechanism

The depression of food intake by high levels of dietary protein and by an excess of l-leucine in a low-protein diet was found to be independent of the presence of the hypothalamic mechanism regulating food intake. At extremely high levels of protein or amino acid intake, the amount of diet ingested was restricted to a similar level in normal and hyperphagic rats. The fact that hyperphagic rats consumed a relatively constant amount of casein in diets containing 60– 90% of protein suggested the possibility that a physiological "safety valve" operated to limit dietary intake so that protein intake did not exceed a certain threshold. An accumulation of amino acids that could not be metabolized or diverted into protein synthesis may have mediated the appetite effects. This suggestion was consistent with the finding that prefeeding high levels of protein (40 or 60% of casein), a procedure which is known to enhance amino acid catabolic activity, temporarily eliminated the appetite depression normally caused by subsequent ingestion of a high-leucine diet.

scholarly journals Does Habituation To High Protein Intake Affect Amino Acid Handling?

2018 ◽  
Vol 50 (5S) ◽  
pp. 838
Author(s):  
Grith Højfeldt ◽  
Jacob Bülow ◽  
Lene Rørdam ◽  
Peter Schjerling ◽  
Jens Bülow ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protein Intake ◽  
High Protein ◽  
High Protein Intake
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