Amino Acids in Premature Infants

PEDIATRICS ◽  
1988 ◽  
Vol 82 (4) ◽  
pp. 680-680
Author(s):  
NIELS C. R. RÄIHÄ

To the Editor.— In a recent paper in Pediatrics, Heird et al1 reported their evaluation of the use of a new amino acid mixture for parenteral nutrition in low birth weight infants. On the basis of their results the authors made the following statement: "These observations refute the concept that the metabolic capacity of LBW infants for amino acids is limited in comparison to that of term infants, older infants, and chi1dren."1(p49) Such a conclusion is not justified on the basis of the presented data.

PEDIATRICS ◽  
1988 ◽  
Vol 82 (3) ◽  
pp. 389-390
Author(s):  
WILLIAM C. HEIRD

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.


PEDIATRICS ◽  
1988 ◽  
Vol 82 (3) ◽  
pp. 388-389
Author(s):  
STANLEY H. ZLOTKIN

To the Editor.— Heird et al1 recently described the use of a new parenteral amino acid mixture for low birth weight infants which included a peptide of tyrosine (N-acetyl-l-tyrosine). They concluded that infants tolerated the new mixture well and stated that it was "more efficacious with respect to nitrogen retention and weight gain than other available mixtures." It is my contention that their results do not substantiate their claims. First, the efficiency of nitrogen retention with TrophAmine (70% retention) is not superior to older amino acid solutions.


1990 ◽  
Vol 259 (2) ◽  
pp. G173-G178 ◽  
Author(s):  
W. H. Nealon ◽  
J. R. Upp ◽  
R. W. Alexander ◽  
G. Gomez ◽  
C. M. Townsend ◽  
...  

Gallbladder stasis during prolonged total parenteral nutrition (TPN) has been documented. We have examined the effect of intravenous amino acid infusion on human gallbladder contraction and release of cholecystokinin (CCK). Five healthy adult volunteers were given amino acid infusions at different rates (65, 125, 240, and 600 mg.kg-1.h-1). The volume of the gallbladder was calculated by means of ultrasonographic measurements. Plasma samples were analyzed for CCK immunoreactivity. Gallbladder and hormone responses after intravenous amino acids were compared with responses after a fat meal, after a protein meal, and after ingestion of an oral amino acid mixture. We found that intravenous amino acids stimulated human gallbladder contraction in a dose-related manner. The mechanism of stimulation may be through the release of CCK although significant correlation was not demonstrated. The magnitude of response is similar to that seen after meal stimulation. To compare the delivery of amino acids during a standard meal and during each dose of intravenous amino acids, peripheral plasma levels of dietary amino acids were measured after a standard commercially prepared enteral supplement meal and after each dose of intravenous amino acids. Our lower doses of amino acid infused resulted in levels of circulating amino acid comparable to those after a meal. The induction of gallbladder contraction and release of CCK in human recipients of parenteral nutrition may be of value in some circumstances.


2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.


1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.


1997 ◽  
Vol 273 (1) ◽  
pp. E122-E129 ◽  
Author(s):  
G. Biolo ◽  
K. D. Tipton ◽  
S. Klein ◽  
R. R. Wolfe

Six normal untrained men were studied during the intravenous infusion of a balanced amino acid mixture (approximately 0.15 g.kg-1.h-1 for 3 h) at rest and after a leg resistance exercise routine to test the influence of exercise on the regulation of muscle protein kinetics by hyperaminoacidemia. Leg muscle protein kinetics and transport of selected amino acids (alanine, phenylalanine, leucine, and lysine) were isotopically determined using a model based on arteriovenous blood samples and muscle biopsy. The intravenous amino acid infusion resulted in comparable increases in arterial amino acid concentrations at rest and after exercise, whereas leg blood flow was 64 +/- 5% greater after exercise than at rest. During hyperaminoacidemia, the increases in amino acid transport above basal were 30-100% greater after exercise than at rest. Increases in muscle protein synthesis were also greater after exercise than at rest (291 +/- 42% vs. 141 +/- 45%). Muscle protein breakdown was not significantly affected by hyperminoacidemia either at rest or after exercise. We conclude that the stimulatory effect of exogenous amino acids on muscle protein synthesis is enhanced by prior exercise, perhaps in part because of enhanced blood flow. Our results imply that protein intake immediately after exercise may be more anabolic than when ingested at some later time.


1982 ◽  
Vol 242 (1) ◽  
pp. E53-E58
Author(s):  
J. G. Yovos ◽  
T. M. O'Dorisio ◽  
T. N. Pappas ◽  
S. Cataland ◽  
F. B. Thomas ◽  
...  

Insulin release following intravenous administration of an amino acid solution with and without a simultaneous infusion of varying amounts of porcine gastric inhibitory polypeptide (GIP) was studied in dogs. Group I received a 10-amino acid mixture (300 mosmol/kg iv) at 16.6 ml/min for 1 h; group II, amino acid mixture plus 0.5 micrograms.kg-1.h-1 porcine GIP; group III, amino acid mixture plus 1.0 micrograms.kg-1.h-1 of GIP; group IV (a and b) received either 0.5 or 1.0 micrograms.kg-1.h-1 of GIP alone. Compared to group I, groups II and III had a greater insulin response during the first 30 min of the infusion. Group] IV (a and b) showed no insulin release. Glucose concentrations showed no significant change in all groups. From these results, it is concluded that insulin release after intravenous infusion of an amino acid mixture plus GIP is greater than after amino acids or GIP alone. It appears that this effect is more pronounced in the early phase of insulin release.


1962 ◽  
Vol 202 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Rapier H. McMenamy ◽  
William C. Shoemaker ◽  
Jonas E. Richmond ◽  
David Elwyn

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.


1971 ◽  
Vol 54 (1) ◽  
pp. 61-65
Author(s):  
Arthur Russell Johnson ◽  
Richard L Corliss ◽  
Enrique Fernandez-Flores

Abstract Qualitative chromatographic methods for the separation of free amino acids in table sirups are presented to aid in the development of chemical indices of composition which may be useful in establishing the identity of sirups and detecting their adulteration. Free amino acids in 2 table sirups were isolated on ion exchange columns and eluted with dilute ammonia. The concentrated amino acid mixture in the eluate was spotted directly on silica gel G plates for TLC analysis, or the amino acids were converted to their N-trifluoroacetyl n-butyl esters for GLC analysis. As many as 16 amino acids were qualitatively separated and identified and a potential for quantitative analysis was demonstrated.


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