scholarly journals Changes in the concentration of specific amino acids in the serum of experimentally malnourished pigs

1970 ◽  
Vol 24 (2) ◽  
pp. 557-564 ◽  
Author(s):  
R. F. Grimble ◽  
R. G. Whitehead
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Protein Content ◽  
Branched Chain Amino Acids ◽  
Serum Amino Acids ◽  
Branched Chain ◽  
Free Serum ◽  
Metabolic Significance

1. The concentrations of individual free serum amino acids have been studied during the course of chronic protein malnutrition in experimentally malnourished pigs.2. Until growth was markedly impaired, reducing the protein content of the diet had no significant effect on serum amino acid composition.3. During the period when growth had practically ceased but kcal intake per kg body-weight was normal the concentrations of valine, leucine, isoleucine, threonine and eventually tyrosine fell, the levels of alanine and serine were above control levels and aspartic acid, glycine, methionine, phenylalanine, proline, arginine, histidine and lysine remained unaltered.4. When the kcal intake per kg fell below control levels, owing to anorexia, and the animals began to lose weight, the levels of alanine, glycine, serine and methionine fell and valine, leucine, isoleucine, threonine and tyrosine remained well below control levels.5. The physiological, nutritional and metabolic significance of these findings is considered. The changes in alanine and glycine concentration are discussed in terms of the regulation of gluconeogenesis. The reduction of the branched-chain amino acids is interpreted on the basis of their availability for synthetic and catabolic needs.

Tumour and Host Tissue Responses to Branched-Chain Amino Acid Supplementation of Patients with Cancer

1994 ◽  
Vol 86 (3) ◽  
pp. 339-345 ◽  
Author(s):  
M. A. McNurlan ◽  
S. D. Heys ◽  
K. G. M. Park ◽  
J. Broom ◽  
D. S. Brown ◽  
...  
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Cancer Patients ◽  
Muscle Tissue ◽  
Branched Chain Amino Acids ◽  
Saline Control ◽  
Intravenous Nutrition ◽  
Branched Chain

1 Rates of protein synthesis have been measured from the incorporation of 57 mg of l-[1-13C]leucine/kg for 90 min into muscle tissue and colorectal tumours removed at surgery from cancer patients. 2. For the 20 h preceding surgery and during the measurement of protein synthesis, the patients received intravenous saline, conventional intravenous nutrition (0.2 g of N and 103 non-protein kJ/kg body weight) or intravenous nutrition enriched with the branched-chain amino acids leucine, isoleucine and valine (0.2 g of N with 30% from branched-chain amino acids and 103 non-protein kJ/kg body weight). 3. Conventional intravenous nutrition resulted in a significant stimulation of the rate of protein synthesis in both muscle tissue (2.64 ± 0.75%/day versus 1.78 ± 0.51%/day in saline control, means ± SD) and tumour tissue (43.9 ± 10.3%/day versus 22.6 ± 5.6%/day in saline control). 4. Pre-operative nutrition enriched with branched-chain amino acids was less effective than conventional intravenous nutrition in stimulating protein synthesis in both muscle and tumour. The rates of protein synthesis were 2.12 ± 0.41%/day in muscle and 33.7 ± 5.3%/day in the tumours. 5. The expression of proliferating cell nuclear antigen in sections of the tumours showed changes with intravenous feeding of the two different amino acid mixtures that were similar to the changes in protein synthesis, and these two variables were significantly correlated. This is evidence that feeding with conventional mixtures and mixtures enriched with branched-chain amino acids stimulates tumour growth. 6. In this study the mixture enriched with branched-chain amino acids provided no clear advantage for cancer patients, since a smaller response to branched-chain amino acids was observed in both tumours and host muscle tissue.

scholarly journals Effects of amino acid preparations on the amino acid composition of the liver of rats under subchronic alcohol intoxication

2020 ◽  
Vol 17 (3) ◽  
pp. 337-345
Author(s):  
Yu. E. Razvodovsky ◽  
V. Yu. Smirnov ◽  
I. N. Semenenya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Free Amino Acids ◽  
Free Amino ◽  
Alcohol Intoxication ◽  
Branched Chain Amino Acids ◽  
Nitrogen Utilization ◽  
Branched Chain

The effects of complex compositions, containing branched-chain amino acids (BCAA), taurine and tryptophan, on the pool of free amino acids in the liver of rats were studied under the conditions of subchronic alcohol intoxication (SHAI). It was established that SHAI led to the decreased levels of treonine, lysine, oxyproline, arginine, b-alanine, as well as the depletion of the pool of irreplaceable amino acids in the liver of rats. Administration of the composition of BCAA and taurine was found to normalize the ratio of replaceable irreplaceable amino acids, the ratio of glycogenic and ketogenic amino acids, to activate the reaction of nitrogen utilization, and to increase Fisher’s index. The effects of the composition, containing BCAA, taurine and tryptophan, were similar to those of amino acid composition that did not contain tryptophan.

scholarly journals Effect of abomasal glucose infusion on alanine metabolism and urea production in sheep

2000 ◽  
Vol 84 (2) ◽  
pp. 157-163 ◽  
Author(s):  
T. Obitsu ◽  
D. Bremner ◽  
E. Milne ◽  
G. E. Lobley
Keyword(s):  
Amino Acids ◽  
Body Weight ◽  
Branched Chain Amino Acids ◽  
Flux Rate ◽  
Plasma Urea ◽  
Exogenous Glucose ◽  
Abomasal Infusion ◽  
Urea Production ◽  
Branched Chain ◽  
N Flux

The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0·75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0·75), based on hay and grass pellets. Glucose provision reduced urinary N (P= 0·040) and urea (P= 0·009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822v. 619 mmol/d,P= 0·024) by glucose while plasma alanine-N flux rate was elevated (295v. 342 mmol/d,P= 0·011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15 %). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.

EFFECT OF VARIETY AND GROWING CONDITIONS ON THE PROTEIN AND AMINO ACID COMPOSITION OF RAPESEED

1963 ◽  
Vol 43 (1) ◽  
pp. 65-67 ◽  
Author(s):  
D. R. Clandinin ◽  
Louise Bayly
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Protein Content ◽  
Essential Amino Acids ◽  
Lysine Content ◽  
Amino Acid Distribution ◽  
Cent Level ◽  
Growing Conditions ◽  
Polish Variety

The protein content and the distribution of essential amino acids in the protein of six varieties or strains of rapeseed grown at three widely separated locations in Alberta, Beaverlodge, Edmonton and Lethbridge, were studied. Differences in protein content and amino acid distribution in the protein of the seed attributable to varietal or strain effects were noted. Turkish and Polish rapeseed were significantly lower in protein content than rapeseed of the Argentine variety. The Argentine variety and the two strains of Argentine-type studied were significantly lower in lysine than the Polish variety. Station differences in protein content approached significance at the 5 per cent level while location had a highly significant effect on the lysine content of the protein of the seed and significant effects on the histidine, arginine, phenylalanine and leucine content.

Removal of infused amino acids by splanchnic and leg tissues in humans

1986 ◽  
Vol 250 (4) ◽  
pp. E407-E413 ◽  
Author(s):  
R. A. Gelfand ◽  
M. G. Glickman ◽  
R. Jacob ◽  
R. S. Sherwin ◽  
R. A. DeFronzo
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Branched Chain Amino Acids ◽  
Acid Uptake ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Significant Uptake ◽  
Branched Chain

To compare the contributions of splanchnic and skeletal muscle tissues to the disposal of intravenously administered amino acids, regional amino acid exchange was measured across the splanchnic bed and leg in 11 normal volunteers. Postabsorptively, net release of amino acids by leg (largely alanine and glutamine) was complemented by the net splanchnic uptake of amino acids. Amino acid infusion via peripheral vein (0.2 g X kg-1 X h-1) caused a doubling of plasma insulin and glucagon levels and a threefold rise in blood amino acid concentrations. Both splanchnic and leg tissues showed significant uptake of infused amino acids. Splanchnic tissues accounted for approximately 70% of the total body amino acid nitrogen disposal; splanchnic uptake was greatest for the glucogenic amino acids but also included significant quantities of branched-chain amino acids. In contrast, leg amino acid uptake was dominated by the branched-chain amino acids. Based on the measured leg balance, body skeletal muscle was estimated to remove approximately 25-30% of the total infused amino acid load and approximately 65-70% of the infused branched-chain amino acids. Amino acid infusion significantly stimulated both the leg efflux and the splanchnic uptake of glutamine (not contained in the infusate). We conclude that when amino acids are infused peripherally in normal humans, splanchnic viscera (liver and gut) are the major sites of amino acid disposal.

Interorgan metabolism of amino acids in streptozotocin-diabetic ketoacidotic rat

1983 ◽  
Vol 244 (2) ◽  
pp. E151-E158 ◽  
Author(s):  
J. T. Brosnan ◽  
K. C. Man ◽  
D. E. Hall ◽  
S. A. Colbourne ◽  
M. E. Brosnan
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Branched Chain Amino Acids ◽  
Diabetic Rats ◽  
Normal Rat ◽  
Diabetic Brain ◽  
Streptozotocin Diabetic Rats ◽  
Branched Chain ◽  
Amino Acid Concentrations

Amino acid concentrations in whole blood, liver, kidney, skeletal muscle, and brain were measured and arteriovenous differences calculated for head, hindlimb, kidney, gut, and liver in control and streptozotocin-diabetic rats. In the control rats, glutamine was released by muscle and utilized by intestine, intestine released citrulline and alanine, liver removed alanine, and the kidneys removed glycine and produced serine. In diabetic rats, the major changes from the pattern of fluxes seen in the normal rat were the release of many amino acids from muscle, with glutamine and alanine predominating, and the uptake of these amino acids by the liver. Glutamine removal by the intestine was suppressed in diabetes, but a large renal uptake of glutamine was evident. Branched-chain amino acids were removed by the diabetic brain, and consequently, brain levels of a number of large neutral amino acids were decreased in diabetes.

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