EFFECT OF TIME FACTOR ON THE NITROGEN SPARING EFFECT OF DIETARY CARBOHYDRATE

1967 ◽  
Vol 45 (11) ◽  
pp. 1653-1658 ◽  
Author(s):  
M. Narayana Rao ◽  
J. M. McLaughlan
Keyword(s):  
Amino Acids ◽  
Liver Glycogen ◽  
Time Factor ◽  
Dietary Carbohydrate ◽  
Elevated Plasma ◽  
Growing Rats ◽  
Amino Acid Levels ◽  
Low Levels ◽  
Sparing Effect ◽  
Glycogen Formation

The effect of the time factor on the nitrogen sparing effect of dietary carbohydrate was studied in growing rats. During a 10-day feeding period no significant differences were observed in weight gains of rats receiving carbohydrate with the dietary protein (casein) or 8 h after protein was fed. Rats receiving carbohydrate with the protein retained significantly more nitrogen during the first day of the experiment than those receiving protein and carbohydrate separately, but this difference was not evident after the first day.Rats receiving casein alone had elevated plasma amino acid levels, which remained high until carbohydrate was fed 8 h later. The pattern of fall of the amino acids bore a resemblance to the pattern of amino acids in carcass protein.Rats fasted for 16 h had low levels of liver glycogen; when protein was given alone, some was utilized for glycogen formation. Carbohydrate, given 8 h after the protein, increased liver glycogen to normal levels and spared the protein fed at the next meal.

Interrelationship between hepatic ureagenesis and gluconeogenesis in early sepsis

1991 ◽  
Vol 260 (3) ◽  
pp. E453-E458 ◽  
Author(s):  
Y. Ohtake ◽  
M. G. Clemens
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Substrate Preference ◽  
Hormone Sensitivity ◽  
Urea Production ◽  
Urea Release ◽  
Amino Acid Levels ◽  
Early Sepsis ◽  
Septic Group

This study was performed to investigate the interrelationship between gluconeogenesis and ureagenesis during sepsis. In isolated perfused livers, gluconeogenesis was assessed using either lactate or a combination of lactate, glutamine, and alanine as substrate. Ureagenesis was assessed using either NH4Cl or glutamine plus alanine as substrate. NH4Cl stimulated urea production in livers from both septic and sham-operated control rats. Urea release was approximately 1.2 and 2.0 mg urea nitrogen.g-1.h-1 for 1 and 5 mM NH4Cl, respectively, and was equal for both groups. With amino acids as substrate, urea production was significantly greater in livers from septic animals compared with controls. Phenylephrine stimulated urea production in the sham-operated group by about twofold, whereas in the septic group urea release was slightly inhibited. Gluconeogenesis from lactate was inhibited by NH4Cl (1 and 5 mM) in both groups, with no difference between groups. In contrast to enhanced ureagenesis from amino acids in septic rats, gluconeogenesis was decreased by approximately 24% (P less than 0.5). Similarly, phenylephrine (1 microM) stimulated gluconeogenesis by 13 +/- 1 mumol.g-1.h-1 in sham-operated rats but only by 9 +/- 1 mumol.g-1.h-1 in septic rats (P less than 0.02). These results suggest that hepatic gluconeogenic and ureagenic pathways are intact in sepsis but that altered substrate preference and hormone sensitivity may result in decreased gluconeogenesis in the presence of elevated amino acid levels.

Liver Glycogen Reserves of Interacting Resident and Introduced Trout Populations

1961 ◽  
Vol 18 (1) ◽  
pp. 125-135 ◽  
Author(s):  
P. W. Hochachka
Keyword(s):  
Population Density ◽  
Liver Glycogen ◽  
Salmo Gairdneri ◽  
Recovery Rates ◽  
Introduced Populations ◽  
Wild Trout ◽  
Low Levels ◽  
Glycogen Stores ◽  
Salmo Clarki

Three groups of trout, two introduced populations of Salmo gairdneri and a resident Salmo clarki, were studied in stream sections. Liver glycogen deposits, which were reduced to low levels during transportation to the stream, were restored in 2 to 3 weeks in all groups, with recovery rates being approximately inverse to the population density. Within the hatchery groups, larger fish laid down greater glycogen stores. Wild trout maintained their high glycogen reserves throughout the experiment.

scholarly journals Amino acids whose intracellular levels change most during aging alter chronological lifespan of fission yeast

2020 ◽  
Author(s):  
Charalampos Rallis ◽  
Michael Mülleder ◽  
Graeme Smith ◽  
Yan Zi Au ◽  
Markus Ralser ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fission Yeast ◽  
Yeast Cells ◽  
Total Amino Acid ◽  
Wild Type ◽  
Chronological Lifespan ◽  
Biomarkers Of Aging ◽  
Concentration Changes ◽  
Amino Acid Levels

AbstractAmino acid deprivation or supplementation can affect cellular and organismal lifespan, but we know little about the role of concentration changes in free, intracellular amino acids during aging. Here, we determine free amino-acid levels during chronological aging of non-dividing fission yeast cells. We compare wild-type with long-lived mutant cells that lack the Pka1 protein of the protein kinase A signalling pathway. In wild-type cells, total amino-acid levels decrease during aging, but much less so in pka1 mutants. Two amino acids strongly change as a function of age: glutamine decreases, especially in wild-type cells, while aspartate increases, especially in pka1 mutants. Supplementation of glutamine is sufficient to extend the chronological lifespan of wild-type but not of pka1Δ cells. Supplementation of aspartate, on the other hand, shortens the lifespan of pka1Δ but not of wild-type cells. Our results raise the possibility that certain amino acids are biomarkers of aging, and their concentrations during aging can promote or limit cellular lifespan.

Utilisation of the end products of ruminant digestion

1957 ◽  
Vol 1957 ◽  
pp. 3-15 ◽  
Author(s):  
D. G. Armstrong ◽  
K. L. Blaxter ◽  
N. McC. Graham
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Quantitative Data ◽  
Volatile Fatty Acids ◽  
Energy Requirement ◽  
The Body ◽  
Energy Requirements ◽  
Dietary Carbohydrate ◽  
Body Tissues ◽  
End Products

The work of the late Sir Joseph Barcroft and his collaborators (see Elsden & Phillipson, 1948) left little doubt that, in ruminants, the end products of the bacterial dissimilation of dietary carbohydrate included large amounts of the steam-volatile fatty acids—acetic, propionic and butyric acids. More recently, el Shazly (1952a, b) has shown that the steam-volatile fatty acids also arise together with ammonia during the bacterial breakdown of amino-acids in the rumen. Studies by Pfander & Phillipson (1953) and Schambye (1955) further indicate that the acids are absorbed from the digestive tract in amounts that suggest they make a major contribution to the energy requirement of the animal. Quantitative data relative to the amounts absorbed, however, are difficult to obtain. Carroll & Hungate (1954) have calculated that in cattle some 6,000-12,000 Cal. of energy are available from the acids produced by fermentation in the rumen. With sheep, Phillipson & Cuthbertson (1956) have calculated from the results of Schambye (1951a, b; 1955) that at least 600-1,200 Cal. of energy in the form of steam-volatile fatty acids could be absorbed every 24 hrs. Since the fasting heat production of the steer is about 6,500 Cal./24 hrs. and that of the sheep about 1,100 Cal./24 hrs. it is clear that if the fatty acids can be utilised efficiently by the body tissues, they could make a major contribution to the energy requirements, at least those for maintenance.

Comparison of the Ileal Digestibility of Amino Acids in Meat and Bone Meal for Broiler Chickens and Growing Rats

2005 ◽  
Vol 4 (4) ◽  
pp. 192-196 ◽  
Author(s):  
V. Ravindran . ◽  
W.H. Hendriks . ◽  
D.V. Thomas . ◽  
P.C.H. Morel . ◽  
C.A. Butts .
Keyword(s):  
Amino Acids ◽  
Broiler Chickens ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Ileal Digestibility ◽  
Growing Rats

Effect of free fatty acids on blood amino acid levels in human

1986 ◽  
Vol 250 (6) ◽  
pp. E686-E694 ◽  
Author(s):  
E. Ferrannini ◽  
E. J. Barrett ◽  
S. Bevilacqua ◽  
R. Jacob ◽  
M. Walesky ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Insulin ◽  
Plasma Free Fatty Acid ◽  
Blood Levels ◽  
Experimental Conditions ◽  
Lipid Infusion ◽  
Amino Acid Levels ◽  
Branched Chain

Raised plasma free fatty acid (FFA) levels effectively impede glucose uptake in vivo, thereby conserving plasma glucose and sparing glycogen. To test whether FFA have any effect on blood amino acid levels, we infused Intralipid plus heparin or saline into healthy volunteers under four different experimental conditions: A) overnight fast; B) euglycemic hyperinsulinemia (approximately 100 microU/ml); C) hyperglycemic (approximately 200 mg/100 ml) hyperinsulinemia (approximately 50 microU/ml); and D) hyperglycemic (approximately 300 mg/100 ml) normoinsulinemia (approximately 20 microU/ml). In the fasting state (A), lipid infusion was associated with lower blood levels of most amino acids, both branched chain and glucogenic. This effect, however, could not be ascribed to lipid infusion alone, because plasma insulin levels were also stimulated. The clamp studies (B, C, and D) allowed to assess the influence of lipid on blood amino acid levels at similar plasma insulin and glucose levels. It was thus observed that lipid infusion has a significant hypoaminoacidemic effect of its own under both euglycemic (B) and hyperglycemic (C) conditions; this effect involved many glucogenic amino acids (alanine, glycine, phenylalanine, serine, threonine, and cystine) but none of the branched-chain amino acids (leucine, isoleucine, and valine). In marked contrast, normoinsulinemic hyperglycemia (D), with or without lipid infusion, caused no change in the blood level of any measured amino acid. We conclude that lipid infusion has a hypoaminoacidemic action. We also suggest that this action is permitted by insulin and may involve specific metabolic interactions (e.g., reduced availability of glucose-derived pyruvate or glycerophosphate) as well as enhanced uptake by the liver.

scholarly journals Supplementation with Bovine Milk or Soy Beverages Recovers Bone Mineralization in Young Growing Rats Fed an Insufficient Diet, in Contrast to an Almond Beverage

2019 ◽  
Vol 3 (11) ◽  
Author(s):  
Julie A Cakebread ◽  
Olivia A M Wallace ◽  
Marlena C Kruger ◽  
Mark H Vickers ◽  
Alison J Hodgkinson
Keyword(s):  
Amino Acids ◽  
Bone Density ◽  
Bone Mineralization ◽  
Bovine Milk ◽  
Biomechanical Properties ◽  
Intact Protein ◽  
Sprague Dawley ◽  
Uht Milk ◽  
Growing Rats ◽  
Sustainable Products

ABSTRACT Background Nondairy beverages, produced from soy, rice, oat, almond, or coconut, are increasingly being used as alternatives to dairy milk, with the perception that they are healthier and/or more sustainable products than dairy products. Objective The aim of this study was to compare the effects of supplementing either bovine milk, soy, or almond-based beverages to young, growing rats fed an intact-protein diet or a diet that had protein substituted with amino acids (AA-diet). Methods Three-week-old male Sprague-Dawley rats were randomly assigned to 5 groups (n = 10/group) and fed ad libitum for 4 wk. Two control groups were fed either standard AIN-93G food [20% casein (CN) protein] or AIN-93G with amino acids (AAs) equivalent to CN protein, and water to drink. Three treatment groups were fed AIN-93G AA and supplemented with either bovine ultra-heat treatment (UHT) milk or soy or almond UHT beverages. Rat weight gain and food intakes were recorded. During week 4, body composition was assessed using DEXA to determine lean soft tissue, fat, and bone mass. At trial end, bone biomechanical properties and blood plasma mineral concentrations were measured. Results At the end of the trial, animals supplemented with almond beverage were lightest (P > 0.05), with higher plasma calcium concentrations (P > 0.05) and lower bone mineral content (BMC) and bone density (P > 0.05) than animals supplemented with milk or soy beverage. Soy-supplemented animals had similar BMC and bone density compared with milk-supplemented animals, although the soy group gained most weight (P > 0.05) and had the highest fat:lean ratio (P > 0.05) compared with other groups. Conclusions In the model tested, supplementing rats with bovine UHT milk and soy UHT beverage provided favorable bone health outcomes. Conversely, almond UHT beverage was not an effective supplement and could be detrimental to bone mineralization and strength outcomes.

scholarly journals How formaldehyde reacts with amino acids

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Jos J. A. G. Kamps ◽  
Richard J. Hopkinson ◽  
Christopher J. Schofield ◽  
Timothy D. W. Claridge
Keyword(s):  
Amino Acids ◽  
Carbonyl Compounds ◽  
Lysine Methylation ◽  
Low Levels

Abstract Formaldehyde is a biological electrophile produced via processes including enzymatic demethylation. Despite its apparent simplicity, the reactions of formaldehyde with even basic biological components are incompletely defined. Here we report NMR-based studies on the reactions of formaldehyde with common proteinogenic and other nucleophilic amino acids. The results reveal formaldehyde reacts at different rates, forming hydroxymethylated, cyclised, cross-linked, or disproportionated products of varying stabilities. Of the tested common amino acids, cysteine reacts most efficiently, forming a stable thiazolidine. The reaction with lysine is less efficient; low levels of an Nε-methylated product are observed, raising the possibility of non-enzymatic lysine methylation by formaldehyde. Reactions with formaldehyde are faster than reactions with other tested biological carbonyl compounds, and the adducts are also more stable. The results reveal reactions of formaldehyde with amino acids, and by extension peptides and proteins, have potential roles in healthy and diseased biology, as well as in evolution.

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