scholarly journals The nitrogen-sparing effect of methionine sulphoxide and some other sulphur-containing amino acids

1982 ◽  
Vol 48 (3) ◽  
pp. 565-570 ◽  
Author(s):  
L. R. Njaa ◽  
A. Aksnes
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
High Protein Diet ◽  
Negative Control ◽  
High Protein ◽  
Protein Diet ◽  
Short Term ◽  
Sparing Effect ◽  
Protein Free Diet

1. The nitrogen-sparing effect of methionine, methionine sulphoxide, homocystme, cystine and choline was studied in rats by determining daily N excretions during 5 d after changing from a high-protein diet to a protein-free diet, L-glutamic acid was used as a negative control.2. L-, D- and DL-methionine were equally active in sparing N. L-methionine sulphoxide, DL-homocystine and L-cystine were as active as L-methionine. D-methionine sulphoxide was slightly less active than L-methionine sulphoxide, Choline hydrogen tartrate was not different from the negative control.3. It is concluded that in short-term experiments cystine is the key substance in the N-sparing effect.

Excretion of Taurine during Healing of Experimental Wounds

1960 ◽  
Vol 6 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Martin B Williamson ◽  
John M Passmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Total Nitrogen ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Nitrogen Excretion ◽  
Amino Acid Nitrogen ◽  
Protein Free Diet

Abstract A comparison of the excretion of amino acids by normal and wounded rats on a high protein and protein-free diet was made. The nontaurine amino acid nitrogen excretion was found to be the same the control and wounded animals, although the rats on the high protein diet excreted considerably more amino acid nitrogen than did those on the protein-free diet. The wounded animals on the high protein diet had the same total nitrogen output but excreted significantly larger amounts of taurine than did the nonwounded controls. The wounded animals given the protein-free diet excreted the same amount of taurine but produced more total nitrogen than did the control rats. On the basis of the total nitrogen-taurine excretion ratios, data indicate that cystine is conserved by the wounded as compared to the normal animals.

scholarly journals The PROMOTE study (High-protein and resistance-training combination in overweight and obesity) for short-term weight loss and long-term weight maintenance for Chinese people: a protocol for a pilot randomized controlled trial

Trials ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Shaoyong Xu ◽  
Juan Zhang ◽  
Yuxiang Dong ◽  
Ruikun Chen ◽  
Wenlei Xu ◽  
...  
Keyword(s):  
Weight Loss ◽  
Resistance Training ◽  
Controlled Trial ◽  
Weight Maintenance ◽  
High Protein Diet ◽  
Diet Group ◽  
High Protein ◽  
Protein Diet ◽  
Short Term ◽  
Low Fat Diet

Abstract Background It is very important for clinicians and dieticians to explore reasonable weight management strategies for obese people that address both short-term weight loss and subsequent weight maintenance. We hypothesized that resistance training combined with a high-protein diet would result in similar short-term weight loss but better long-term weight maintenance than either a conventional low-fat diet control or a high-protein diet alone. Methods/design This is an 8-week randomized parallel controlled trial followed by a 24-week observational follow-up study. A 48-week supplementary follow-up study will be carried out if necessary. The study will be conducted between June 2019 and October 2020. The 90 overweight or obese participants will be randomly assigned to the conventional low-fat diet group, the high-protein diet group and the high-protein diet and resistance training combination group. Primary outcomes are body weight change at week 8 and week 24 compared with the baseline level. Discussion High-quality research on the effect of a high-protein diet combined resistance training on weight loss and weight maintenance is limited in the Chinese population. Our study will provide a basis for obesity management in China and will promote the development of exercise- and diet-related studies. Trial registration Chinese Clinical Trial Registry, ChiCTR1900023841. Registered on 14 June 2019.

Supplementing An Energy Adequate High Protein Diet With Additional Protein Is Not Necessary For Recovery Of Lean Body Mass After Short-term Starvation

2016 ◽  
Vol 48 ◽  
pp. 443
Author(s):  
John J. Sepowitz ◽  
Holly L. McClung ◽  
Claire E. Berryman ◽  
Nicholes J. Armstrong ◽  
Arny A. Ferrando ◽  
...  
Keyword(s):  
Lean Body Mass ◽  
Body Mass ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Short Term ◽  
Additional Protein

scholarly journals The effects of a combination of high-protein diet and resistance training on short-term weight loss and long-term weight maintenance in overweight and obese Chinese people: a study protocol

2019 ◽  
Author(s):  
Xu Shaoyong ◽  
Juan Zhang ◽  
Yuxiang Dong ◽  
Ruikun Chen ◽  
Wenlei Xu ◽  
...  
Keyword(s):  
Weight Loss ◽  
Resistance Training ◽  
Weight Maintenance ◽  
High Protein Diet ◽  
Diet Group ◽  
High Protein ◽  
Protein Diet ◽  
Short Term ◽  
Low Fat Diet

Abstract Background It is very important for clinicians and dieticians to explore reasonable weight management strategies for obese people that address both short-term weight loss and subsequent weight maintenance. We hypothesized that resistance training combined with a high-protein diet would result in similar short-term weight loss but better long-term weight maintenance than either conventional low-fat diet control or high-protein diet alone.Methods/design This is an 8-week randomized parallel controlled trial followed by a 24-week observational follow-up study. A 48-week supplementary follow-up study will be carried out if necessary. The study will be conducted between June 2019 and October 2020. The 90 overweight or obese participants will be randomly assigned to the conventional low-fat diet group, the high-protein diet group and the high-protein diet and resistance training combination group. Primary outcomes are body weight changes at week 8 and week 24 compared with the baseline level.Discussion High-quality research on the effect of a high-protein diet combined resistance training on weight loss and weight maintenance is limited in Chinese population. Our study will provide a basis for obesity management in China, and promote the development of exercise and diet-related studies.Trials registration ChiCTR1900023841, 14 June 2019

Splanchnic sequestration of amino acids in aged rats: in vivo and ex vivo experiments using a model of isolated perfused liver

2008 ◽  
Vol 294 (3) ◽  
pp. R748-R755 ◽  
Author(s):  
M. Jourdan ◽  
L. Cynober ◽  
C. Moinard ◽  
M. C. Blanc ◽  
N. Neveux ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ex Vivo ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Aged Rats ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Urea Production

Splanchnic sequestration of amino acids (SSAA) is a process observed during aging that leads to decreased peripheral amino acid (AA) availability. The mechanisms underlying SSAA remain unknown. The aim of the present study was to determine whether a high-protein diet could increase nitrogen retention in aged rats by saturating SSAA and whether SSAA could be explained by dysregulation of hepatic nitrogen metabolism. Adult and aged male Sprague-Dawley rats were housed in individual metabolic cages and fed a normal-protein (17% protein) or high-protein diet (27%) for 2 wk. Nitrogen balance (NB) was calculated daily. On day 14, livers were isolated and perfused for 90 min to study AA and urea fluxes. NB was lower in aged rats fed a normal-protein diet than in adults, but a high-protein diet restored NB to adult levels. Isolated perfused livers from aged rats showed decreased urea production and arginine uptake, together with a release of alanine (vs. uptake in adult rats) and a hepatic accumulation of alanine. The in vivo data suggest that SSAA is a saturable process that responds to an increase in dietary protein content. The hepatic metabolism of AA in aged rats is greatly modified, and urea production decreases. This result refutes the hypothesis that SSAA is associated with an increase in AA disposal via urea production.

Fluxes and membrane transport of amino acids in rat liver under different protein diets

1990 ◽  
Vol 259 (5) ◽  
pp. E614-E625 ◽  
Author(s):  
P. Fafournoux ◽  
C. Remesy ◽  
C. Demigne
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aromatic Amino Acids ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Transport Systems ◽  
Low Concentrations ◽  
Significant Uptake

The aim of the present work was to evaluate in vivo the role of the transport step in hepatic amino acid metabolism. To vary hepatic utilization of amino acids, rats were adapted to diets containing various concentrations of casein (5, 15, and 60%). In rats fed 5 or 15% casein diets, Gln and Glu were released by the liver, and there was a significant uptake of Ala. Hepatic fluxes of amino acids increased considerably after adaptation to high-casein diet (up to 1.55 mumol.min-1.g liver-1 for Ala), because of the rise in afferent concentrations as well as enhanced uptake percentage (peaking at 60–75% for most glucogenic amino acids). Adaptation to a high-protein diet led to induction of not only system A but also of most of the other transport systems (Gly, anionic, T, y+, and to a lesser extent system N); only systems ASC and L were unchanged. The study of amino acid repartition between liver and plasma with different diets indicates that transport could modulate utilization of Ala, Ser, Thr, Gly, Gln, and Asp. For Arg and Asn, present in very low concentrations in liver under any condition, the transport step should be the major locus of control of their metabolism. For amino acids chiefly transported by nonconcentrative systems, such as aromatic amino acids, cellular metabolism could also be limited by the transport process. In conclusion, during adaptation to a high-protein diet, there is apparently a coordinated adaptation of amino acid transport and of their intracellular metabolism. For some amino acids, induction of catabolic enzymes seems greater than that of transport, so that the transport step may play an important role in control of metabolic fluxes. For example, concentration of amino acids such as Thr may be markedly depressed in rats adapted to a high-protein diet.

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