An intragastric amino acid mixture influences extracellular amino acid profiles in the lateral hypothalamic area of freely moving rats

1999 ◽  
Vol 77 (11) ◽  
pp. 827-834 ◽  
Author(s):  
Yang-Ho Choi ◽  
Nancy Chang ◽  
G Harvey Anderson
Keyword(s):  
Amino Acid ◽  
Amino Acid Mixture ◽  
Lateral Hypothalamic Area ◽  
Acid Mixture ◽  
Hypothalamic Area ◽  
Lateral Hypothalamic ◽  
Freely Moving Rats ◽  
Freely Moving ◽  
Amino Acid Concentrations ◽  
Extracellular Amino Acid

We tested the effect of equicaloric loads of glucose (0.89 g) or a balanced amino acid mixture (0.85 g) on extracellular amino acid concentrations in the brains of freely moving rats. At 15:30 hours, the microdialysis probe was inserted into the lateral hypothalamic area of ambulatory rats, and food and water were removed. Dialysates were collected every 20 min from 1 h prior to gavage (18:00 hours) and until 3 h after the gavage. Amino acid concentrations in the dialysate were determined by reverse-phase HPLC. Following the amino acid gavage, extracellular amino acid concentrations significantly increased from baseline for alanine, isoleucine, leucine, methionine, threonine, tyrosine, and valine. Those elevations occurred within 20-40 min following the amino acid load, and lasted up to 100 min. After the glucose and water treatments, amino acid concentrations were either not affected or gradually diminished from baseline. We conclude that extracellular amino acid concentration in the lateral hypothalamus is influenced by the composition of food consumed.Key words: blood-brain barrier, food intake, glucose, microdialysis, protein.

TrophAmine

PEDIATRICS ◽  
1988 ◽  
Vol 82 (3) ◽  
pp. 389-390
Author(s):  
WILLIAM C. HEIRD
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
Low Birth Weight ◽  
Controlled Trial ◽  
Nitrogen Retention ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Concerted Effort ◽  
Low Birth Weight Infants ◽  
Amino Acid Concentrations

In Reply.— The purpose of the study reported in the paper1 to which Zlotkin refers was to evaluate the efficacy of a new parenteral amino acid mixture (ie, TrophAmine) with respect to maintaining "normal" plasma amino acid concentrations and promoting nitrogen retention in low birth weight infants. Because the study was not a controlled trial in which this amino acid mixture was compared with another mixture, a concerted effort was made to avoid drawing conclusions or stating claims regarding the efficacy of this amino acid mixture relative to other mixtures.

Uptake and metabolism of amino acids by the dog liver perfused in situ

1962 ◽  
Vol 202 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Rapier H. McMenamy ◽  
William C. Shoemaker ◽  
Jonas E. Richmond ◽  
David Elwyn
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Sharp Rise ◽  
Dog Blood ◽  
Dog Liver ◽  
Amino Acid Concentrations ◽  
Uptake And Metabolism

Dog livers were perfused in situ for periods up to 6 hr with dog blood recycled through a pump-oxygenator. An amino acid mixture was administered for 90 min. Concentrations of amino acids were determined at intervals of 30 min or more. Rates of uptake and metabolism were calculated. After the start of perfusion, there is a fall in most plasma amino acid concentrations and a reciprocal rise in liver amino acids. Addition of amino acids causes a sharp rise in plasma amino acids. There is a rapid uptake of most of the amino acids by liver, although the concentrations of amino acids in liver fail to rise appreciably. Notable exceptions are valine, leucine, and isoleucine. Uptake of amino acids stimulates: a) an increase in the rate of synthesis of urea which ultimately accounts for 90% of the metabolized amino acids; b) a net synthesis of ornithine; and c) net noncatabolic metabolism of amino acids which may in part be protein synthesis. The results support the view that the liver temporarily stores a part of ingested amino acids as proteins, and subsequently makes them available to other organs.

scholarly journals Changes in plasma amino acid concentrations in man after ingestion of an amino acid mixture simulating casein, and a tryptic hydrolysate of casein

1975 ◽  
Vol 34 (2) ◽  
pp. 259-265 ◽  
Author(s):  
T. C. Marrs ◽  
Jill M. Addison ◽  
D. Burston ◽  
D. M. Matthews
Keyword(s):  
Amino Acid ◽  
Amino Acid Mixture ◽  
Plasma Amino Acid ◽  
Acid Mixture ◽  
Protein Digestion ◽  
Endogenous Protein ◽  
Small Doses ◽  
Tryptic Hydrolysate ◽  
Amino Acid Levels ◽  
Amino Acid Concentrations

1. Plasma amino acid levels have been estimated at 0, 15, 30 and 45 min after ingestion of doses of (1) an amino acid mixture simulating casein and (2) a tryptic hydrolysate of casein consisting mainly of oligopeptides. Both doses contained the same amount of nitrogen.2. After ingestion of both preparations, there was a prompt increase in plasma amino acid levels, followed by a decrease. No such change occurred in fasting subjects. There were no significant differences between increments in plasma amino acid levels after ingestion of the amino acid mixture and the corresponding increments after ingestion of the tryptic hydrolysate.3. Correlations were found between the areas under the curves for individual amino acid concentrations, after ingestion of the two preparations, and the amino acid composition of casein. The results do not suggest that increases in plasma amino acid levels following small doses of protein digestion products are the result of circadian changes, or that such increases are ‘swamped’ by absorption of amino acids from endogenous protein in the lumen of the small intestine.

Amino Acid Concentrations in Portal Venous Plasma during Absorption from the Small Intestine of the Guinea Pig of an Amino Acid Mixture Simulating Casein and a Partial Enzymic Hydrolysate of Casein

1977 ◽  
Vol 52 (3) ◽  
pp. 259-267
Author(s):  
M. H. Sleisenger ◽  
D. Pelling ◽  
D. Burston ◽  
D. M. Matthews
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Guinea Pig ◽  
Preliminary Investigation ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Analytical Technique ◽  
Amino Acid Mixtures ◽  
Amino Acid Concentrations ◽  
Venous Plasma

1. The characteristics of absorption of individual amino acids from amino acid mixtures simulating casein and from enzymic hydrolysates of casein containing oligopeptides as well as free amino acids are known to be different. The differences, which are attributable to mucosal uptake of small peptides, involve more rapid absorption from the enzymic hydrolysates of certain amino acids which are relatively slowly absorbed from the amino acid mixtures. This could lead to more effective utilization of amino acids from the enzymic hydrolysates than from the amino acid mixtures. 2. To obtain further information bearing on this hypothesis, we have used a recently developed technique for portal cannulation in the guinea pig to make a preliminary investigation of amino acid concentrations in the portal venous plasma at intervals after the infusion into the duodenum of equivalent amounts of (a) an amino acid mixture simulating casein and (b) a partial enzymic (papain followed by kidney peptidases) hydrolysate of casein, the two preparations being infused in separate experiments. 3. For some amino acids, such as leucine, isoleucine, valine, phenylalanine and lysine, the curves after the enzymic hydrolysate were fairly similar to the corresponding curves after the amino acid mixture, though usually slightly lower. With other amino acids, the curves after the enzymic hydrolysate were very much lower than the corresponding curves after the amino acid mixture. With serine, glutamine, proline and glycine this discrepancy was particularly great. 4. The results cannot yet be fully explained, but their main features are explicable by the hypothesis that the lower amino acid concentrations in portal plasma after the enzymic hydrolysate are the result of entry of amino acids into the portal blood in peptide form, in which they would not be detectable by the analytical technique employed, and possibly also of more rapid clearance of amino acids from the blood during absorption of this preparation.

Physiological augmentation of amino acid-induced insulin secretion by GIP and GLP-I but not by CCK-8

1995 ◽  
Vol 268 (5) ◽  
pp. E949-E955 ◽  
Author(s):  
P. Fieseler ◽  
S. Bridenbaugh ◽  
R. Nustede ◽  
J. Martell ◽  
C. Orskov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plasma Glucose ◽  
Gastric Inhibitory Polypeptide ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Slight Reduction ◽  
Acid Infusion ◽  
C Peptide ◽  
Amino Acid Infusion ◽  
Amino Acid Concentrations

It was the aim of this study to test insulinotropic actions of cholecystokinin octapeptide (CCK-8), gastric inhibitory polypeptide (GIP), and glucagon-like peptide I (GLP-I)-(7--36) amide at basal glucose but physiologically elevated amino acid concentrations. Therefore, in nine fasting healthy volunteers, an amino acid mixture was infused intravenously (12.6 g/h over 120 min). On separate occasions, from 30 to 120 min, placebo (0.9% NaCl-1% human serum albumin), synthetic sulfated CCK-8 (0.5 pmol.kg-1.min-1), human GIP (1 pmol.kg-1.min-1), or GLP-I-(7--36) amide (0.3 pmol.kg-1.min-1) was infused intravenously to mimic physiological increments after a meal. The amino acid infusion lead to a small increment in plasma glucose from 4.8 +/- 0.2 to 5.0 +/- 0.2 mmol/l and significantly elevated insulin and C-peptide concentrations. GIP and GLP-I-(7--36) amide further stimulated insulin (1.8-fold, P = 0.0001 and 0.004, respectively) and C-peptide (1.3-fold, P = 0.0003 and 0.013, respectively), with a subsequent slight reduction in plasma glucose (P < 0.0001). Insulin and C-peptide then decreased again in parallel. CCK-8 was without effect on insulin and C-peptide levels. In conclusion, GIP and GLP-I-(7--36) amide are not only able to interact with elevated plasma glucose but are insulinotropic also with physiologically raised amino acid concentrations. Such an interaction could play a role after the ingestion of mixed meals. Cholecystokinin, on the other hand, is not a physiological incretin also under these conditions.

An open-label, single-center pilot study to test the effects of an amino acid mixture in older patients admitted to internal medicine wards

Nutrition ◽  
2020 ◽  
Vol 69 ◽  
pp. 110588 ◽  
Author(s):  
Francesco Bellanti ◽  
Aurelio Lo Buglio ◽  
Elena Di Stasio ◽  
Giorgia di Bello ◽  
Rosanna Tamborra ◽  
...  
Keyword(s):  
Internal Medicine ◽  
Amino Acid ◽  
Pilot Study ◽  
Older Patients ◽  
Amino Acid Mixture ◽  
Acid Mixture ◽  
Single Center ◽  
Open Label ◽  
Internal Medicine Wards

Choosing A Balanced Amino Acid Mixture

1970 ◽  
Vol 100 (3) ◽  
pp. 380-380 ◽  
Author(s):  
Hans Fisher
Keyword(s):  
Amino Acid ◽  
Amino Acid Mixture ◽  
Acid Mixture
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