scholarly journals Protein nutrition of the neonate

2000 ◽  
Vol 59 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Peter J. Reeds ◽  
Douglas G. Burrin ◽  
Teresa A. Davis ◽  
Marta L. Fiorotto ◽  
Barbara Stoll ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Milk Proteins ◽  
Well Being ◽  
High Rate ◽  
Anabolic Response ◽  
Nutrient Density ◽  
Tissue Protein Synthesis ◽  
General Aspects

The period of growth and development between birth and weaning is crucial for the long-term well-being of the organism. Protein deposition is very rapid, is achieved with a high nutritional efficiency, and is accompanied by marked differences in the growth rates of individual tissues and a series of maturational processes. These important aspects of development occur while the neonate is consuming a single and highly-specific food source, milk. Surprisingly, although there is a clear relationship between the nutrient density of milk and the growth rate of its recipient, this relationship does not apply to the overall amino acid composition of mixed milk proteins. Some amino acids, notably glycine and arginine, are supplied in milk in quantities that are much less than the needs of the neonate. The milk-fed neonate is therefore capable of carrying out a tightly-regulated transfer of N from amino acids in excess to those that are deficient. The rapid growth of the neonate is supported by a high rate of tissue protein synthesis. This process appears to be activated by the consumption of the first meals of colostrum. Recent research has identified that skeletal muscle and the brain are specifically responsive to an unidentified factor in colostrum. Following the initial anabolic response the rate of protein synthesis in some tissues, notably muscle, falls from birth to weaning. This decrease reflects a progressively smaller anabolic response to nutrient intake, which not only involves an overall fall in the capacity for protein synthesis, but also in responses to insulin and amino acids. The study of growth and protein metabolism, and their regulation in the neonate is not only important for pediatrics, but may provide important pointers to more general aspects of regulation that could be applied to the nutrition of the mature animal.

Long-term organic and conventional farming effects on nutrient density of oats

2021 ◽  
pp. 1-15
Author(s):  
Emmanuel Chiwo Omondi ◽  
Marisa Wagner ◽  
Atanu Mukherjee ◽  
Kristine Nichols
Keyword(s):  
Amino Acids ◽  
Cropping Systems ◽  
Vitamin B1 ◽  
Essential Amino Acids ◽  
Total Carbon ◽  
Nutrient Concentrations ◽  
Amino Acid Synthesis ◽  
Organic Systems ◽  
Nutrient Density

Abstract Declining nutrient densities of crops in the past 50–70 years have been attributed to unsound agricultural practices and plant breeding focus on yield rather than quality. Few studies have quantified the soil and nutritional quality of grains in organic and conventional farms and reported results are scarce and inconsistent. The Rodale Institute's Farming Systems Trial (FST) was established in 1981 to quantify the effects of long-term organic and conventional grain cropping systems and tillage practices. A 2014 study to quantify effects on the nutrient density of oat grains was integrated into three systems within the long-term trial: organic manure-based (MNR), organic legume-based (LEG), and conventional synthetic input-based (CNV), split between tilled (T) and no-till (NT) practices. Oat grains with hulls removed were analyzed for minerals (n = 24), vitamins (n = 24), amino acids (n = 24) and proteins (n = 24), while soil samples to a depth of 10 cm were analyzed for elemental minerals, and total carbon (C), nitrogen (N) and sulfur (S). Organic systems increased six out ten soil minerals whose concentrations were influenced by cropping systems: aluminum (Al), iron (Fe), chromium (Cr), calcium (Ca), barium (B) and strontium (Sr). All essential amino acids were greater in oat grains under LEG systems compared with other systems except lysine, histidine and methionine. Both LEG systems also increased 12 out of 13 non-essential amino acids in oat grains. Total oat N, C and S required for amino acid synthesis tended to be greater in organic systems. Soil N, C and S were highly correlated with total oat amino acids under organic systems compared to CNV. Organic LEG had significantly greater vitamin B1 than MNR and CNV. These results suggest that nutrient concentrations of oat grains were greater in organic systems compared to CNV systems, and the increase could be partially explained by the long-term soil management differences between the systems.

Effects of milk proteins supplementation on muscle protein synthesis

2019 ◽  
Vol 49 (6) ◽  
pp. 1275-1286
Author(s):  
Milena Casagranda ◽  
Priscila Berti Zanella ◽  
Alexandra Ferreira Vieira ◽  
Rodrigo Cauduro Oliveira Macedo
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Protein Biosynthesis ◽  
Nitrogen Compound ◽  
Milk Proteins ◽  
Control Group ◽  
Content Type ◽  
Protein Sources

Purpose The purpose of the study was to evaluate the acute effect of milk proteins supplementation, compared to another nitrogen compound on muscle protein synthesis. Design/methodology/approach The search was conducted on MEDLINE® (via PUBMED®), Cochrane and Embase databases, using the terms “whey proteins,” “caseins,” “milk proteins,” “protein biosynthesis,” “human” and its related entry terms. The selected outcome was fractional synthetic rate (FSR) before (0) and 3 h after consumption of milk proteins, compared to supplementation with other protein sources or isolated amino acids. Findings The results were expressed as mean difference (MD) of absolute values between treatments with confidence interval (CI) of 95 per cent. Of the 1,913 identified studies, 4 were included, with a total of 74 participants. Milk proteins generated a greater FSR (MD 0.03 per cent/h, CI 95 per cent 0.02-0.04; p < 0.00001), compared to control group. Acute consumption of milk proteins promotes higher increase in FSR than other protein sources or isolated amino acids. Originality/value This paper is a systematic review of the effects of milk proteins supplementation, which is considered an important subject because of its large consumption among athletes and physical exercise practitioners.

scholarly journals Acute IGF-I infusion stimulates protein synthesis in skeletal muscle and other tissues of neonatal pigs

2002 ◽  
Vol 283 (4) ◽  
pp. E638-E647 ◽  
Author(s):  
Teresa A. Davis ◽  
Marta L. Fiorotto ◽  
Douglas G. Burrin ◽  
Rhonda C. Vann ◽  
Peter J. Reeds ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Cardiac Muscle ◽  
Liver Protein ◽  
Tissue Protein ◽  
Neonatal Pigs ◽  
Igf I ◽  
Tissue Protein Synthesis ◽  
Insulin Replacement

Studies have shown that protein synthesis in skeletal muscle of neonatal pigs is uniquely sensitive to a physiological rise in both insulin and amino acids. Protein synthesis in cardiac muscle, skin, and spleen is responsive to insulin but not amino acid stimulation, whereas in the liver, protein synthesis responds to amino acids but not insulin. To determine the response of protein synthesis to insulin-like growth factor I (IGF-I) in this model, overnight-fasted 7- and 26-day-old pigs were infused with IGF-I (0, 20, or 50 μg · kg−1 · h−1) to achieve levels within the physiological range, while amino acids and glucose were clamped at fasting levels. Because IGF-I infusion lowers circulating insulin levels, an additional group of high-dose IGF-I-infused pigs was also provided replacement insulin (10 ng · kg−0.66 · min−1). Tissue protein synthesis was measured using a flooding dose ofl-[4-3H]phenylalanine. In 7-day-old pigs, low-dose IGF-I increased protein synthesis by 25–60% in various skeletal muscles as well as in cardiac muscle (+38%), skin (+24%), and spleen (+32%). The higher dose of IGF-I elicited no further increase in protein synthesis above that found with the low IGF-I dose. Insulin replacement did not alter the response of protein synthesis to IGF-I in any tissue. The IGF-I-induced increases in tissue protein synthesis decreased with development. IGF-I infusion, with or without insulin replacement, had no effect on protein synthesis in liver, jejunum, pancreas, or kidney. Thus the magnitude, tissue specificity, and developmental change in the response of protein synthesis to acute physiological increases in plasma IGF-I are similar to those previously observed for insulin. This study provides in vivo data indicating that circulating IGF-I and insulin act on the same signaling components to stimulate protein synthesis and that this response is highly sensitive to stimulation in skeletal muscle of the neonate.

Suppression of muscle protein turnover and amino acid degradation by dietary protein deficiency

1992 ◽  
Vol 263 (2) ◽  
pp. E317-E325 ◽  
Author(s):  
N. E. Tawa ◽  
A. L. Goldberg
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dietary Protein ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Normal Diet ◽  
High Rate ◽  
Acid Uptake ◽  
Rapid Weight Gain

To define the adaptations that conserve amino acids and muscle protein when dietary protein intake is inadequate, rats (60-70 g final wt) were fed a normal or protein-deficient (PD) diet (18 or 1% lactalbumin), and their muscles were studied in vitro. After 7 days on the PD diet, both protein degradation and synthesis fell 30-40% in skeletal muscles and atria. This fall in proteolysis did not result from reduced amino acid supply to the muscle and preceded any clear decrease in plasma amino acids. Oxidation of branched-chain amino acids, glutamine and alanine synthesis, and uptake of alpha-aminoisobutyrate also fell by 30-50% in muscles and adipose tissue of PD rats. After 1 day on the PD diet, muscle protein synthesis and amino acid uptake decreased by 25-40%, and after 3 days proteolysis and leucine oxidation fell 30-45%. Upon refeeding with the normal diet, protein synthesis also rose more rapidly (+30% by 1 day) than proteolysis, which increased significantly after 3 days (+60%). These different time courses suggest distinct endocrine signals for these responses. The high rate of protein synthesis and low rate of proteolysis during the first 3 days of refeeding a normal diet to PD rats contributes to the rapid weight gain ("catch-up growth") of such animals.

scholarly journals Differential effects of long-term leucine infusion on tissue protein synthesis in neonatal pigs

Amino Acids ◽  
2010 ◽  
Vol 40 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Fiona A. Wilson ◽  
Agus Suryawan ◽  
Renán A. Orellana ◽  
María C. Gazzaneo ◽  
Hanh V. Nguyen ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Tissue Protein ◽  
Differential Effects ◽  
Neonatal Pigs ◽  
Tissue Protein Synthesis

scholarly journals Optimal well-being in the aftermath of anxiety disorders: A 10-year longitudinal investigation

2021 ◽  
Author(s):  
David Disabato ◽  
Todd Barrett Kashdan ◽  
James Doorley ◽  
Kerry Kelso ◽  
Kristina Volgenau ◽  
...  
Keyword(s):  
Anxiety Disorder ◽  
Well Being ◽  
The United States ◽  
High Rate ◽  
Major Depressive ◽  
Longitudinal Investigation ◽  
Nationally Representative ◽  
Primary Hypothesis

Background: Although preliminary research has explored the possibility of optimal well-being after depression, it is unclear how rates compare to anxiety. Using Generalized Anxiety Disorder (GAD) and Panic Disorder (PD) as exemplars of anxiety, we tested the rates of optimal well-being one decade after being diagnosed with an anxiety disorder. Based on reward deficits in depression, we pre-registered our primary hypothesis that optimal well-being would be more prevalent after anxiety than depression as well as tested two exploratory hypotheses.Method: We used data from the Midlife in the United States (MIDUS) study, which contains a nationally representative sample across two waves, 10 years apart. To reach optimal well-being, participants needed to have no symptoms of GAD, PD, or major depressive disorder (MDD) at the 10 year follow-up and exceed cut-offs across nine dimensions of well-being.Results: The results failed to support our primary hypothesis. Follow-up optimal well-being rates were highest for adults previously diagnosed with MDD (8.7%), then PD (6.1%), and finally GAD (0%). Exploratory analyses revealed optimal well-being was approximately twice as prevalent in people without anxiety or depression at baseline and provided partial support for baseline well-being predicting optimal well-being after anxiety. Results were largely replicated across different classifications of optimal well-being.Limitations: Findings are limited by the somewhat unique measurement of anxiety in the MIDUS sample as well as the relatively high rate of missing data.Conclusions: We discuss possible explanations for less prevalent optimal well-being after anxiety vs. depression and the long-term positivity deficits from GAD.

Changes in protein synthesis in embryonic axes after long-term storage of maize seeds

1992 ◽  
Vol 2 (4) ◽  
pp. 191-198
Author(s):  
R. Aguilar ◽  
E. Reynoso ◽  
M. Albores ◽  
E. Sánchez de Jiménez
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Protein Synthesis ◽  
Seed Storage ◽  
Specific Cell ◽  
Embryonic Axes ◽  
Maize Seeds ◽  
Long Term Storage ◽  
Layer Chromatography

AbstractThe aim of this work was to analyse the capacity for protein synthesis in embryonic axes from long-term-stored maize seeds, including the role of proline. Embryonic axes from seeds stored for 13 years (S) and non-stored seeds (NS) were incubated in nutrient media after application of [14C]proline. Transformation of [14C]proline into other amino acids was analysed by thin-layer chromatography. After 6 h of incubation, no other labelled amino acids were found. Incorporation of 14C into total soluble and cell-wall (proline-rich) proteins was assessed during this period. Incorporation of [14C]proline into specific cell-wall proteins was lower in S than in NS axes.Studies using [35S]methionine showed that protein synthesis was slower in axes of S than in NS seeds. Analyses of these proteins by gel electrophoresis and fluorography revealed qualitative differences between the [35S]methionine proteins synthesized by both types of axes. The NS: S ratios for the [35S]proteins were larger than those from the [14C]proline assays. These data may be interpreted as an indication of differential deterioration of transcription or translation in the axes during long-term seed storage.

scholarly journals Glutathione Supplementation of Parenteral Nutrition Prevents Oxidative Stress and Sustains Protein Synthesis in Guinea Pig Model

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2063 ◽  
Author(s):  
Guillaume Morin ◽  
Clémence Guiraut ◽  
Marisol Perez Marcogliese ◽  
Ibrahim Mohamed ◽  
Jean-Claude Lavoie
Keyword(s):  
Oxidative Stress ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Parenteral Nutrition ◽  
Lipid Emulsion ◽  
Gastrocnemius Muscle ◽  
Limited Growth ◽  
Low Levels ◽  
Guinea Pig Model

Peroxides contaminating parenteral nutrition (PN) limit the use of methionine as a precursor of cysteine. Thus, PN causes a cysteine deficiency, characterized by low levels of glutathione, the main molecule used in peroxide detoxification, and limited growth in individuals receiving long-term PN compared to the average population. We hypothesize that glutathione supplementation in PN can be used as a pro-cysteine that improves glutathione levels and protein synthesis and reduces oxidative stress caused by PN. One-month-old guinea pigs (7–8 per group) were used to compare glutathione-enriched to a non-enriched PN, animals on enteral nutrition were used as a reference. PN: Dextrose, amino acids (Primene), lipid emulsion (Intralipid), multivitamins, electrolytes; five-day infusion. Glutathione (GSH, GSSG, redox potential) and the incorporation of radioactive leucine into the protein fraction (protein synthesis index) were measured in the blood, lungs, liver, and gastrocnemius muscle. Data were analysed by ANOVA; p < 0.05 was considered significant. The addition of glutathione to PN prevented the PN-induced oxidative stress in the lungs and muscles and supported protein synthesis in liver and muscles. The results potentially support the recommendation to add glutathione to the PN and demonstrate that glutathione could act as a biologically available cysteine precursor.

Measurement of human tissue protein synthesis: an optimal approach

1994 ◽  
Vol 266 (3) ◽  
pp. E298-E307 ◽  
Author(s):  
M. J. Rennie ◽  
K. Smith ◽  
P. W. Watt
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Continuous Infusion ◽  
Human Tissue ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Whole Body ◽  
Skeletal Muscle Protein ◽  
Tissue Protein ◽  
Tissue Protein Synthesis

This paper reviews the evidence for and against the adoption of methods for the measurement of human tissue protein synthesis based upon the incorporation of stable isotopically labeled amino acids administered either as a continuous infusion or as a flooding dose. The practical advantages of the flooding dose method are the relative ease of application of the tracer and the ability to make a repeat measurement within approximately 2 h. For the method depending upon continuous infusion of labeled amino acid, the advantages include the use of labeled amino acids at true tracer doses (i.e., with no disturbance of metabolism) and the ability to make simultaneous measurements of whole body turnover and limb or organ turnover (given appropriate sampling techniques). The crucial question concerning the accuracy of the two methods (e.g., the 2-fold difference in the rate of skeletal muscle protein synthesis) remains unresolved, but in our opinion more evidence exists in favor of the values obtained from the continuous infusion method. Furthermore, as techniques for measurement of stable isotopically labelled amino acids improve, the length of time necessary for tracer infusion will fall, and the practical advantages of the flooding dose protocol will lessen in comparison.

scholarly journals Glycine restores the anabolic response to leucine in a mouse model of acute inflammation

2016 ◽  
Vol 310 (11) ◽  
pp. E970-E981 ◽  
Author(s):  
Daniel J. Ham ◽  
Marissa K. Caldow ◽  
Victoria Chhen ◽  
Annabel Chee ◽  
Xuemin Wang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Muscle Wasting ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Antioxidant Properties ◽  
Anabolic Response ◽  
Anti Inflammatory

Amino acids, especially leucine, potently stimulate protein synthesis and reduce protein breakdown in healthy skeletal muscle and as a result have received considerable attention as potential treatments for muscle wasting. However, the normal anabolic response to amino acids is impaired during muscle-wasting conditions. Although the exact mechanisms of this anabolic resistance are unclear, inflammation and ROS are believed to play a central role. The nonessential amino acid glycine has anti-inflammatory and antioxidant properties and preserves muscle mass in calorie-restricted and tumor-bearing mice. We hypothesized that glycine would restore the normal muscle anabolic response to amino acids under inflammatory conditions. Relative rates of basal and leucine-stimulated protein synthesis were measured using SUnSET methodology 4 h after an injection of 1 mg/kg lipopolysaccharide (LPS). Whereas leucine failed to stimulate muscle protein synthesis in LPS-treated mice pretreated with l-alanine (isonitrogenous control), leucine robustly stimulated protein synthesis (+51%) in mice pretreated with 1 g/kg glycine. The improvement in leucine-stimulated protein synthesis was accompanied by a higher phosphorylation status of mTOR, S6, and 4E-BP1 compared with l-alanine-treated controls. Despite its known anti-inflammatory action in inflammatory cells, glycine did not alter the skeletal muscle inflammatory response to LPS in vivo or in vitro but markedly reduced DHE staining intensity, a marker of oxidative stress, in muscle cross-sections and attenuated LPS-induced wasting in C2C12 myotubes. Our observations in male C57BL/6 mice suggest that glycine may represent a promising nutritional intervention for the attenuation of skeletal muscle wasting.

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