Effects of early amino acid administration during total parenteral nutrition on protein metabolism in pre-term infants

1992 ◽  
Vol 82 (2) ◽  
pp. 199-203 ◽  
Author(s):  
R. A. van Lingen ◽  
J. B. van Goudoever ◽  
I. H. T. Luijendijk ◽  
J. L. D. Wattimena ◽  
P. J. J. Sauer
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Birth Weight ◽  
Amino Acid ◽  
Protein Breakdown ◽  
Protein Balance ◽  
15N Enrichment ◽  
Group A ◽  
Group B ◽  
Acid Administration

1. We investigated the effects of starting amino acid administration on post-natal day 2 on protein turnover and nitrogen balance in appropriate-for-gestational-age, very-low-birth-weight infants. Eighteen infants were divided into two groups. Group A received from day 2 onwards an amino acid solution, whereas group B started on this solution after day 4. Both groups were exclusively parenterally fed, 200 kJ day−1 kg−1 on post-natal days 3 and 4. Group A (birth weight 1.5 ± 0.3 kg) received 4.6 g of glucose, 1.9 g of fat and 2.3 g of amino acids day−1 kg−1 body weight. Group B (birth weight 1.4 ± 0.2 kg) received 7.0 g of glucose and 1.9 g of fat day−1 kg−1 body weight. 2. At post-natal day 3, a primed constant infusion of 3 mg of [15N]glycine day−1 kg−1 was given. Protein flux, protein synthesis and protein breakdown were calculated from the 15N enrichment in urinary ammonia. In five out of nine infants in group B no plateau of 15N enrichment in urinary urea could be detected, whereas in group A two out of nine infants did not reach a plateau. For this reason we did not use the end product urea for our calculations. 3. The administration of the amino acids resulted in a higher protein flux (6.9 ± 1.5 g day−1 kg−1 versus 5.2 ± 0.9 g day−1 kg−1) and a higher protein synthesis rate (6.0 ± 1.4 g day−1 kg−1 versus 4.6 ± 0.8 g day−1 kg−1) in group A. There was no statistically significant difference in protein breakdown. The administration of amino acids reversed a negative protein balance (−0.6 ± 0.2 g day−1 kg−1) into a positive one (1.4 ± 0.2 g day−1 kg−1. No adverse effects of the amino acid infusion were seen. 4. We conclude that the early introduction of amino acids has, even at this relatively low energy intake of 200 kJ day−1 kg−1, a positive effect on protein balance by increasing protein synthesis.

Effect of hyperinsulinemia and hyperaminoacidemia on muscle and liver protein synthesis in lactating goats

1994 ◽  
Vol 267 (6) ◽  
pp. E877-E885 ◽  
Author(s):  
I. Tauveron ◽  
D. Larbaud ◽  
C. Champredon ◽  
E. Debras ◽  
S. Tesseraud ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Skeletal Muscles ◽  
Constant Infusion ◽  
Acid Mixture ◽  
Liver Protein ◽  
Group I ◽  
Lactating Goats ◽  
Group A

The experiment was carried out to clarify the roles of insulin and amino acids on protein synthesis in fed lactating goats (30 days postpartum). Protein synthesis in the liver and various skeletal muscles was assessed after an intravenous injection of a large dose of unlabeled valine containing a tracer dose of L-[2,3,4-3H]valine. The animals were divided into three groups. Group I was infused with insulin (1.7 mumol/min) for 2.5 h under glucose, potassium, and amino acid replacement. Group A was infused with an amino acid mixture to create stable hyperaminoacidemia for 2.5 h. Group C animals were controls. The fractional synthesis rates (FSR) were 31.5 +/- 2.2, 6.5 +/- 0.4, 4.3 +/- 0.8, 4.0 +/- 1.2, 3.9 +/- 1.2, and 3.6 +/- 0.4%/day (SD) in liver, masseter, diaphragm, anconeus, semitendinosus, and longissimus dorsi, respectively, for group C. Neither hyperinsulinemia in group I nor hyperaminoacidemia in group A had not affected by hyperinsulinemia but was stimulated by hyperaminoacidemia (+30%, P < 0.05). In contrast to previous experiments in which a labeled amino acid was constantly infused, this study revealed a stimulating effect of amino acids on protein synthesis in the liver but not in skeletal muscles. As previously observed in studies with the constant-infusion method, insulin had no effect on protein synthesis.

scholarly journals A Single Amino Acid Change within Antigenic Domain II of the Spike Protein of Bovine Coronavirus Confers Resistance to Virus Neutralization

2001 ◽  
Vol 8 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Dongwan Yoo ◽  
Dirk Deregt
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Spike Protein ◽  
Single Amino Acid ◽  
Single Point Mutation ◽  
Bovine Coronavirus ◽  
Single Amino Acid Change ◽  
Group A ◽  
Escape Mutants ◽  
Group B

ABSTRACT The spike glycoprotein is a major neutralizing antigen of bovine coronavirus (BCV). Conformational neutralizing epitopes of group A and group B monoclonal antibodies (MAbs) have previously been mapped to two domains at amino acids 351 to 403 (domain I) and amino acids 517 to 621 (domain II). To further map antigenic sites, neutralization escape mutants of BCV were selected with a group A MAb which has both in vitro and in vivo virus-neutralizing ability. The escape mutants were demonstrated to be neutralization resistant to the selecting group A MAb and remained sensitive to neutralization by a group B MAb. In radioimmunoprecipitation assays, the spike proteins of neutralization escape mutants were shown to have lost their reactivities with the selecting group A MAb. Sequence analysis of the spike protein genes of the escape mutants identified a single nucleotide substitution of C to T at position 1583, resulting in the change of alanine to valine at amino acid position 528 (A528V). The mutation occurs in domain II and in a location which corresponds to the hypervariable region of the spike protein of the coronavirus mouse hepatitis virus. Experimental introduction of the A528V mutation into the wild-type spike protein resulted in the loss of MAb binding of the mutant protein, confirming that the single point mutation was responsible for the escape of BCV from immunological selective pressure.

scholarly journals Postexercise net protein synthesis in human muscle from orally administered amino acids

1999 ◽  
Vol 276 (4) ◽  
pp. E628-E634 ◽  
Author(s):  
Kevin D. Tipton ◽  
Arny A. Ferrando ◽  
Stuart M. Phillips ◽  
David Doyle ◽  
Robert R. Wolfe
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Random Order ◽  
Essential Amino Acids ◽  
Constant Infusion ◽  
Protein Balance

We examined the response of net muscle protein synthesis to ingestion of amino acids after a bout of resistance exercise. A primed, constant infusion ofl-[ ring-2H5]phenylalanine was used to measure net muscle protein balance in three male and three female volunteers on three occasions. Subjects consumed in random order 1 liter of 1) a mixed amino acid (40 g) solution (MAA), 2) an essential amino acid (40 g) solution (EAA), and 3) a placebo solution (PLA). Arterial amino acid concentrations increased ∼150–640% above baseline during ingestion of MAA and EAA. Net muscle protein balance was significantly increased from negative during PLA ingestion (−50 ± 23 nmol ⋅ min−1 ⋅ 100 ml leg volume−1) to positive during MAA ingestion (17 ± 13 nmol ⋅ min−1 ⋅ 100 ml leg volume−1) and EAA (29 ± 14 nmol ⋅ min−1 ⋅ 100 ml leg volume−1; P < 0.05). Because net balance was similar for MAA and EAA, it does not appear necessary to include nonessential amino acids in a formulation designed to elicit an anabolic response from muscle after exercise. We concluded that ingestion of oral essential amino acids results in a change from net muscle protein degradation to net muscle protein synthesis after heavy resistance exercise in humans similar to that seen when the amino acids were infused.

Whole body protein kinetics in women: effect of pregnancy and IDDM during anabolic stimulation

2000 ◽  
Vol 279 (5) ◽  
pp. E978-E988 ◽  
Author(s):  
Paul G. Whittaker ◽  
Choy H. Lee ◽  
Roy Taylor
Keyword(s):  
Amino Acids ◽  
Type 1 Diabetes ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Metabolism ◽  
Whole Body ◽  
Protein Breakdown ◽  
Body Protein ◽  
In Pregnancy

The effects of pregnancy and type 1 diabetes [insulin-dependent diabetes mellitus (IDDM)] on protein metabolism are still uncertain. Therefore, six normal and five IDDM women were studied during and after pregnancy, using [13C]leucine and [2H5]phenylalanine with a hyperinsulinemic-euglycemic clamp and amino acid infusion. Fasting total plasma amino acids were lower in pregnancy in normal but not IDDM women (2,631 ± 427 vs. 2,057 ± 471 and 2,523 ± 430 vs. 2,500 ± 440 μmol/l, respectively). Whole body protein breakdown (leucine) increased in pregnancy [change in normal (ΔN) and IDDM women (ΔD) 0.59 ± 0.40 and 0.48 ± 0.26 g · kg−1 · day−1, both P < 0.001], whereas reductions in protein breakdown due to insulin/amino acids (ΔN −0.57 ± 0.19, ΔD −0.58 ± 0.20 g · kg−1 · day−1, both P < 0.001) were unaffected by pregnancy. Protein breakdown in IDDM women was not higher than normal, and neither pregnancy nor type 1 diabetes altered the insulin sensitivity of amino acid turnover. Nonoxidized leucine disposal (protein synthesis) increased in pregnancy (ΔN 0.67 ± 0.45, ΔD 0.64 ± 0.34 g · kg−1 · day−1, both P < 0.001). Pregnancy reduced the response of phenylalanine hydroxylation to insulin/amino acids in both groups (ΔN −1.14 ± 0.74, ΔD −1.12 ± 0.77 g · kg−1 · day−1, both P < 0.05). These alterations may enable amino acid conservation for protein synthesis and accretion in late pregnancy. Well-controlled type 1 diabetes caused no abnormalities in the regulation of basal or stimulated protein metabolism.

Splanchnic and whole body L-[1-13C,15N]leucine kinetics in relation to enteral and parenteral amino acid supply

1992 ◽  
Vol 262 (5) ◽  
pp. E687-E694 ◽  
Author(s):  
Y. M. Yu ◽  
J. F. Burke ◽  
J. A. Vogt ◽  
L. Chambers ◽  
V. R. Young
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Jugular Vein ◽  
Whole Body ◽  
Protein Breakdown ◽  
Metabolic Fate ◽  
Amino Acid Solution ◽  
Leucine Kinetics ◽  
Body Parameters ◽  
Acid Administration

The effect of the route of administration of a complete amino acid solution (0.24 g.kg-1.h-1) on leucine (Leu) and alpha-ketoisocaproate (KIC) metabolism in the splanchnic region (Sp) was assessed in nine chronically catherized mongrel dogs receiving, for 6 h, amino acids by jugular vein (PN feeding). Results were compared with those obtained previously [Y. M. Yu, D. A. Wagner, E. E. Tredget, J.A. Waleszewski, J. F. Burke, and V. R. Young. Am. J. Physiol. 259 (Endocrinol. Metab. 22): E36-E51, 1990] in eight dogs similarly studied but given amino acids by constant enteral feeding (EN). We used primed continuous intravenous infusions of L-[1-13C,15N]Leu and measurements of arteriovenous isotope and Leu balance across the gut, liver, and Sp to estimate parameters of whole body and organ Leu metabolism [Leu-N and Leu-C flux, Leu----KIC; KIC----Leu, Leu oxidation and rates of Leu appearance (B) from and disappearance (S) into proteins]. Whole body Leu kinetics were the same for both routes of amino acid administration. With PN, KIC----Leu, Leu----KIC, and total metabolic processing were lower than for EN in Sp, and overall Leu balance (S - B) was higher in Sp for EN. Leu appearance from protein breakdown in gut was higher with PN. The rate of KIC----Leu was higher in liver for EN. These findings reveal that route of amino acid (Leu) administration, under these acute feeding conditions, alters the processing and metabolic fate of Leu in Sp but that whole body parameters of Leu metabolism are stable. The implications of these metabolic findings in relation to the maintenance of intestinal function and integrity are discussed.

Amino acid repletion does not decrease muscle protein catabolism during hemodialysis

2007 ◽  
Vol 292 (6) ◽  
pp. E1534-E1542 ◽  
Author(s):  
Dominic S. C. Raj ◽  
Oladipo Adeniyi ◽  
Elizabeth A. Dominic ◽  
Michel A. Boivin ◽  
Sandra McClelland ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Breakdown ◽  
Protein Catabolism ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Muscle Protein Breakdown

Intradialytic protein catabolism is attributed to loss of amino acids in the dialysate. We investigated the effect of amino acid infusion during hemodialysis (HD) on muscle protein turnover and amino acid transport kinetics by using stable isotopes of phenylalanine, leucine, and lysine in eight patients with end-stage renal disease (ESRD). Subjects were studied at baseline (pre-HD), 2 h of HD without amino acid infusion (HD-O), and 2 h of HD with amino acid infusion (HD+AA). Amino acid depletion during HD-O augmented the outward transport of amino acids from muscle into the vein. Increased delivery of amino acids to the leg during HD+AA facilitated the transport of amino acids from the artery into the intracellular compartment. Increase in muscle protein breakdown was more than the increase in synthesis during HD-O (46.7 vs. 22.3%, P < 0.001). Net balance (nmol·min−1·100 ml −1) was more negative during HD-O compared with pre-HD (−33.7 ± 1.5 vs. −6.0 ± 2.3, P < 0.001). Despite an abundant supply of amino acids, the net balance (−16.9 ± 1.8) did not switch from net release to net uptake. HD+AA induced a proportional increase in muscle protein synthesis and catabolism. Branched chain amino acid catabolism increased significantly from baseline during HD-O and did not decrease during HD+AA. Protein synthesis efficiency, the fraction of amino acid in the intracellular pool that is utilized for muscle protein synthesis decreased from 42.1% pre-HD to 33.7 and 32.6% during HD-O and HD+AA, respectively ( P < 0.01). Thus amino acid repletion during HD increased muscle protein synthesis but did not decrease muscle protein breakdown.

scholarly journals Genetic Variability among Group A and Group B Respiratory Syncytial Viruses in a Children’s Hospital

1998 ◽  
Vol 36 (12) ◽  
pp. 3552-3557 ◽  
Author(s):  
Wanicha Buraphacheep Coggins ◽  
Elliot J. Lefkowitz ◽  
Wayne M. Sullender
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Genetic Variability ◽  
G Protein ◽  
Variable Region ◽  
Children's Hospital ◽  
Children’S Hospital ◽  
Group A ◽  
Protein Amino Acids ◽  
Group B

Respiratory syncytial (RS) viruses isolated over three epidemic periods in a children’s hospital in the United States were analyzed. The viruses (n = 174) were characterized as to major antigenic group (group A or B) by a PCR-based assay. Group A RS viruses were dominant the first 2 years, followed by a year with group B dominance (ratios of group A to group B viruses for epidemic periods, 56/4 for 1993–1994, 42/3 for 1994–1995, and 19/50 for 1995–1996). Genetic variability within the groups was assessed by restriction fragment analysis of PCR products; 79 isolates were also analyzed by nucleotide sequence determination of a variable region of the glycoprotein G gene. Among the group A RS virus isolates, this G-protein variable region had amino acid differences of as great as 38%. The G-protein amino acids of the group A viruses differed by up to 31% from the G-protein amino acids of a prototype (A2) group A virus. Among the group B RS virus G proteins, amino acid differences were as great as 14%. The G-protein amino acids of the group B viruses differed by up to 27% from the G-protein amino acids of a prototype (18537) group B virus. The group A and group B RS viruses demonstrated genetic variability between years and within individual years. Phylogenetic analysis revealed that there were multiple evolutionary lineages among both the group A and group B viruses. Among the recent group B isolates, variability was less than that seen for the group A viruses. However, comparisons to prototype strains revealed that the group B RS viruses may vary more extensively than was observed over the 3 years studied in the present investigation.

scholarly journals Inverse Regulation of Protein Turnover and Amino Acid Transport in Skeletal Muscle of Hypercatabolic Patients

2002 ◽  
Vol 87 (7) ◽  
pp. 3378-3384 ◽  
Author(s):  
Gianni Biolo ◽  
R. Y. Declan Fleming ◽  
Sergio P. Maggi ◽  
Thuan T. Nguyen ◽  
David N. Herndon ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Transmembrane Transport ◽  
Protein Breakdown ◽  
Balance Technique

We have investigated the relationships between the rates of muscle protein synthesis and degradation and of transmembrane transport of selected amino acids in leg skeletal muscle of 19 severely burned patients and 18 normal controls in the postabsorptive state. Patients were studied on the 14 ± 5 postburn day, and their mean burn size was 66% ± 18% of total body surface area. Methods were based on the leg arteriovenous balance technique in combination with biopsies of the vastus lateralis muscle and infusions of isotopic tracers of amino acids. Net muscle protein breakdown was greater in the patients because of an 83% increase in the rate of muscle protein degradation. The rate of muscle protein synthesis was also increased in the patients but to a lesser extent than protein degradation, i.e. by 50% with the arteriovenous phenylalanine balance technique and by 49% with the direct tracer incorporation method. The absolute values of inward transport of phenylalanine, leucine, and lysine were not significantly different in the two groups. However, the ability of transport systems to take up amino acids from the bloodstream, as assessed by dividing inward transport by amino acid delivery to leg muscle, were 50–63% lower in the patients. In contrast, outward phenylalanine and lysine transport were 40% and 67% greater in the patients than in the controls, respectively. We conclude the primary alteration in muscle protein metabolism is an acceleration of protein breakdown, and the increase in protein synthesis likely is due to increased intracellular amino acid availability as a result of accelerated breakdown. Transmembrane transport in the outward direction is accelerated, presumably to facilitate the export of amino acids from muscle to other tissues. In contrast, transmembrane transport in the inward direction is impaired relatively to the increased delivery of circulating amino acid to skeletal muscle secondary to accelerated blood flow.

scholarly journals Diminished Systemic Amino Acids Metabolome and Lipid Peroxidation in Ureteropelvic Junction Obstruction (UPJO) Infants Requiring Surgery

2021 ◽  
Vol 10 (7) ◽  
pp. 1467
Author(s):  
Olga Begou ◽  
Antigoni Pavlaki ◽  
Olga Deda ◽  
Alexander Bollenbach ◽  
Kathrin Drabert ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lipid Peroxidation ◽  
Statistical Analysis ◽  
Ureteropelvic Junction Obstruction ◽  
Ureteropelvic Junction ◽  
Obstructive Nephropathy ◽  
Conservative Group ◽  
Surgery Group ◽  
Group A ◽  
Group B

Congenital anomalies of the urinary tract, and particularly of obstructive nephropathy such as ureteropelvic junction obstruction (UPJO) in infants, can later lead to chronic kidney disease and hypertension. Fundamental questions regarding underlying mechanisms remain unanswered. The aim of the present study was to quantitate the systemic amino acids metabolome in 21 UPJO infants requiring surgery (Group A) and 21 UPJO infants under conservative treatment (Group B). Nineteen healthy age-matched infants served as controls (Group C). Serum amino acids involved in several pathways and representative metabolites, including the L-arginine-derived nitric oxide (NO) metabolites nitrite and nitrate and the lipid peroxidation biomarker malondialdehyde (MDA) were measured by gas chromatography–mass spectrometry (GC–MS) methods using their stable-isotope labeled analogs as internal standards after derivatization to their methyl esters N-pentafluoropropionic amides (amino acids) and to their pentafluorobenzyl derivatives (nitrite, nitrate, MDA). The concentrations of the majority of the biomarkers were found to be lower in Group A compared to Group B. Statistical analysis revealed clear differentiation between the examined study groups. Univariate statistical analysis highlighted serum homoarginine (q = 0.006), asymmetric dimethylarginine (q = 0.05) and malondialdehyde (q = 0.022) as potential biomarkers for UPJO infants requiring surgery. Group A also differed from Group B with respect to the diameter of the preoperative anterior–posterior renal pelvis (AP) as well as regarding the number and extent of inverse correlations between AP and the serum concentrations of the biomarkers. In Group A, but not in Group B, the AP diameter strongly correlated with hydroxy-proline (r = −0.746, p = 0.0002) and MDA (r = −0.754, p = 0.002). Our results indicate a diminished amino acids metabolome in the serum of UPJO infants requiring surgery comparing to a conservative group.

scholarly journals 146 Prematurity Blunts the Protein Synthetic Response of Skeletal Muscle to Insulin and Amino Acids

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 118-119
Author(s):  
Teresa A Davis ◽  
Marko Rudar ◽  
Jane Naberhuis ◽  
Agus Suryawan ◽  
Marta Fiorotto
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Body Weight Gain ◽  
Human Infant ◽  
Long Term Effects ◽  
Plasma Insulin Concentration ◽  
Akt Phosphorylation ◽  
Relative Body Weight

Abstract Livestock animals are important dual-purpose models that benefit both agricultural and biomedical research. The neonatal pig is an appropriate model for the human infant to assess long-term effects of early life nutrition on growth and metabolic outcomes. Previously we have demonstrated that prematurity blunts the feeding-induced stimulation of translation initiation and protein synthesis in skeletal muscle of neonatal pigs. The objective of this study was to determine whether reduced sensitivity to insulin and/or amino acids drives this blunted response. Pigs were delivered by caesarean section at preterm (PT, 103 d gestation) or at term (T, 112 d gestation) and fed parenterally for 4 d. On day 4, pigs were subject to euinsulinemic-euaminoacidemic-euglycemic (FAST), hyperinsulinemic-euaminoacidemic-euglycemic (INS), or euinsulinemic-hyperaminoacidemic-euglycemic (AA) clamps for 120 min, yielding six treatments: PT-FAST (n = 7), PT-INS (n = 9), PT-AA (n = 9), T-FAST (n = 8), T-INS (n = 9), and T-AA (n = 9). A flooding dose of L-[4-3H]Phe was injected into pigs 30 min before euthanasia. Birth weight and relative body weight gain were lower in PT than T pigs (P &lt; 0.001). Plasma insulin concentration was increased from ~3 to ~100 µU/mL in INS compared to FAST and AA pigs (P &lt; 0.001); plasma BCAA concentration was increased from ~250 to ~1,000 µmol/L in AA compared to FAST and INS pigs (P &lt; 0.001). Despite achieving similar insulin and amino acid levels, longissimus dorsi AKT phosphorylation, mechanistic target of rapamycin (mTOR)·Rheb abundance, mTOR activation, and protein synthesis were lower in PT-INS than T-INS pigs (Table 1). Although amino-acid induced dissociation of Sestrin2 from GATOR2 was not affected by prematurity, mTOR·RagA abundance, mTOR·RagC abundance, mTOR activation, and protein synthesis were lower in PT-AA than T-AA pigs. The impaired capacity of premature skeletal muscle to respond to insulin or amino acids and promote protein synthesis likely contributes to reduced lean mass accretion. Research was supported by NIH and USDA.

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