scholarly journals The regulation of l-asparaginase activity in rats and mice. Effects of normal and malignant growth, of sex and of dietary changes

1969 ◽  
Vol 115 (3) ◽  
pp. 597-601 ◽  
Author(s):  
E. Bonetti ◽  
Ada Abbondanza ◽  
E. Della Corte ◽  
F. Stirpe
Keyword(s):  
Enzyme Activity ◽  
High Protein Diet ◽  
Protein Diet ◽  
Regenerating Liver ◽  
Newborn Rats ◽  
Malignant Growth ◽  
Low Protein ◽  
Morris Hepatoma ◽  
Asparaginase Activity ◽  
Rats And Mice

1. The activity of l-asparaginase was very low in the liver of newborn rats and mice, and increased within a few days of birth. 2. In rats, but not in mice, the enzyme activity was higher in females than in males, was enhanced by administration of oestradiol, and was decreased by gonadectomy. 3. The enzyme activity decreased in mice starved or fed on a low-protein diet; in rats it was enhanced by starvation, by feeding them on a high-protein diet, or by administration of l-asparagine. 4. The asparaginase activity was decreased in regenerating liver, and was almost absent in the Morris hepatoma 5123.

Regulation and Characterization of L-Serine: Pyruvate Aminotransferase in Rat Liver Cytosol and Mitochondria

1977 ◽  
Vol 32 (3-4) ◽  
pp. 249-253 ◽  
Author(s):  
Jiro Hoshino ◽  
Uta Kühne ◽  
Branka Filjak ◽  
Hans Kröger
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
High Protein Diet ◽  
Mitochondrial Fraction ◽  
Protein Diet ◽  
Low Protein ◽  
Rat Liver Cytosol

Abstract Distribution of rat liver serine: pyruvate aminotransferase between cytosol and mitochondria varies considerably with the dietary and hormonal state of animals. Feeding a high-protein diet or fasting the animals results in an increase in the enzyme activity of both fractions but more marked in the mitochondrial fraction. A low-protein diet exerts the reverse effect. A single administration of dibutyryl cyclic AMP causes a rapid elevation of the enzyme activity in both fractions, which is effectively prevented by cycloheximide, actinomycin D and cortisone. The activity in mitochondria increases with a lag of 2 h following injection of the nucleotide inducer, in contrast to the cytosol enzyme, which increases without any lag. Gel filtration and DEAE cellulose chromatography of the enzyme from both fractions revealed the similar pattern and some kinetic constants of these two types of the enzyme were not significantly different from each other. These results indicate that rat liver serine: pyruvate aminotransferase is synthesized in the extra-mitochondrial site and transfered to mitochondria.

scholarly journals Adaptive changes in the capacity of systems used for the synthesis of citrulline in rat liver mitochondria in response to high- and low-protein diets

1974 ◽  
Vol 142 (2) ◽  
pp. 359-364 ◽  
Author(s):  
J. D. McGivan ◽  
Norah M. Bradford ◽  
J. B. Chappell
Keyword(s):  
Nitrogen Source ◽  
High Protein Diet ◽  
Liver Mitochondria ◽  
High Protein ◽  
Protein Diet ◽  
Rat Liver Mitochondria ◽  
Standard Diet ◽  
Adaptive Changes ◽  
Low Protein ◽  
Citrulline Synthesis

1. Citrulline synthesis was measured in mitochondria from rats fed on a standard diet, a high-protein diet, or on glucose. 2. With NH4Cl as the nitrogen source the rate of citrulline synthesis was higher in mitochondria from rats fed on a high-protein diet than in those from rats fed on a standard diet. When rats were fed solely on glucose the rate of synthesis of citrulline from NH4Cl was very low. 3. With glutamate as the nitrogen source the relative rates of citrulline synthesis were much lower than when NH4Cl was present, but similar adaptive changes occurred. 4. The activity of the mitochondrial glutamate-transporting system increased two to three times on feeding rats on a high-protein diet, but the Km for glutamate was unchanged. 5. Adaptive changes in certain intramitochondrial enzymes were also measured. 6. The results were interpreted to indicate that when an excess of substrate was present, citrulline synthesis from NH4Cl was rate-limited by the intramitochondrial concentration of N-acetyl-glutamate, but citrulline synthesis from glutamate was rate-limited primarily by the activity of the glutamate-transporting system.

Effect of High-Salt, High-Carbohydrate, Low-Protein Diet on Hypertension in the Rat

1973 ◽  
Vol 45 (s1) ◽  
pp. 99s-102s
Author(s):  
Hideo Ueda
Keyword(s):  
Blood Pressure ◽  
High Protein Diet ◽  
Normal Diet ◽  
High Salt ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Heart Weight ◽  
Hypertensive Rats ◽  
High Carbohydrate ◽  
Low Protein

1. High-salt, high-carbohydrate and low-protein diet induces remarkable elevation of blood pressure in spontaneous hypertensive rats (SHR). 2. These animals have low serum potassium, low blood urea nitrogen and high blood sugar. 3. Heart weight is increased in proportion to the elevation of blood pressure. 4. Kidney weight of rats receiving the high-salt, high-carbohydrate and low-protein diet was, by contrast, smaller than SHR receiving a normal diet. 5. The kidneys of SHR receiving a high-salt, high-protein diet were twice as heavy as the kidneys of normal rats. 6. Similar dietary modifications in Goldblatt hypertensive rats to those in SHR produced similar changes in blood pressure and heart weight.

scholarly journals Performance of Broilers Fed Low Protein Diets with Lysine and Methionine Supplements

2006 ◽  
Vol 6 (1) ◽  
pp. 47-59
Author(s):  
Nancy Montilla ◽  
◽  
Lolito Bestil ◽  
Sulpecio Bantugan ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
High Protein Diet ◽  
Protein Diet ◽  
Amino Acid Supplementation ◽  
Feed Conversion ◽  
Broiler Performance ◽  
Acid Supplementation ◽  
Low Protein

A feeding trial with broilers was conducted to evaluate the effects of amino acids (lysine and methionine) supplementation of diets low in protein content on the voluntary intake, feed conversion efficiency, broiler performance, and cost and return of broiler production. Results showed cumulative voluntary feed intake was not significantly affected by lowering the protein content of the diet. Cumulative weight gain of broilers was lower with diet when supplemented iwht lysine and methionine to meet requirements. Birds fed with diets low in protein has less efficient feed converstion, but became comparable with those receiveing diets high in protein when supplemented with amino acids. Feed cost per kilogram broiler produced was not significantly affected by diets used in the study, although the low-protien diet with amino acid supplement had the lowest values. In terms of return above feed and chick cost, broilers fed with high-protein diet had the greatest value, but not significantly different from birds fed with low-protien diet with amino acid supplementation which gave about P10 per bird higher returns than those fed low-protein diet without amino acid supplementation.

scholarly journals High‐protein diet more effectively reduces hepatic fat than low‐protein diet despite lower autophagy and FGF21 levels

2020 ◽  
Vol 40 (12) ◽  
pp. 2982-2997 ◽  
Author(s):  
Chenchen Xu ◽  
Mariya Markova ◽  
Nicole Seebeck ◽  
Anne Loft ◽  
Silke Hornemann ◽  
...  
Keyword(s):  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Low Protein Diet ◽  
Low Protein ◽  
Hepatic Fat

Digestion by sheep of concentrate diets containing formaldehyde-treated peanut meal

1972 ◽  
Vol 23 (5) ◽  
pp. 859 ◽  
Author(s):  
GJ Faichney
Keyword(s):  
Organic Matter ◽  
Peanut Meal ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Plasma Urea ◽  
Protein Levels ◽  
Low Protein ◽  
Formaldehyde Treatment ◽  
Protein Diets

The effect of formaldehyde treatment of peanut meal on the digestion of barley-peanut meal diets was studied in fistulated crossbred sheep at two peanut meal and therefore dietary protein levels. There were no differences either between protein levels or due to treatment in the overall digestion of organic matter, but more of this digestion took place in the stomach when the low protein diets were given. Dietary starch was completely digested. There was no effect of protein level or of formaldehyde treatment on the partition of starch digestion between the stomach and the intestines. About 10% of the dietary nitrogen disappeared from the stomach when the high protein diet containing untreated peanut meal was given; treatment resulted in a small net gain of nitrogen in the stomach. There was a net gain of nitrogen in the stomach when the low protein diets were given, the gain tending to be greater when the peanut meal was treated. When the meal was treated, there was a small but not significant increase (c. 2%) for the low protein diet and a substantial increase (c. 31 %) for the high protein diet in the amount of crude protein digested in the intestines per unit of digestible organic matter intake. Changes observed in the composition and flow of digesta and in plasma urea and cc-amino nitrogen levels are discussed in relation to the digestion of organic matter and protein.

scholarly journals RECIPROCAL CHANGES IN PLASMA PROTEIN AND PLASMA ACACIA AS RESULT OF HIGH AND LOW PROTEIN DIETS

1950 ◽  
Vol 91 (4) ◽  
pp. 425-431 ◽  
Author(s):  
R. E. Knutti ◽  
J. B. Goetsch ◽  
R. A. Warrick
Keyword(s):  
Protein Content ◽  
Plasma Protein ◽  
Protein Concentration ◽  
High Protein Diet ◽  
The Body ◽  
Protein Diet ◽  
Plasma Protein Concentration ◽  
Gum Acacia ◽  
Normal Limits ◽  
Low Protein

Dogs were made hypoproteinemic by repeated injections of gum acacia, and the acacia injections were discontinued. Diets of varying protein content were then given. When a high protein diet is provided the plasma protein concentration increases; with a low protein diet, or under conditions of fasting, the plasma protein concentration diminishes. Similarly, plasma acacia concentration shows increases and decreases which are reciprocal to the protein variations. Total circulating plasma protein and total circulating plasma acacia show similar changes. In all instances total circulating colloid (acacia plus protein) concentration adds up to an amount within normal limits for protein alone. The results indicate that under these conditions, acacia stored in the body (principally in the liver) can be removed from its site of deposit and returned to the blood. The data also show that dogs in which acacia is deposited in large quantities, require a larger amount of protein in the diet to maintain a constant plasma protein content than do normal dogs. It appears that the mechanism for maintenance of peripheral colloidal material may be dependent on differences in intracellular and extracellular colloidal osmotic pressure. The experiments also support the idea that plasma protein molecules, as well as gum acacia, may pass in and out of cells through the cell membranes.

Analysis of hormonal–dietary interactions and the role of gluconeogenesis in the regulation of tyrosine aminotransferase in rats

1969 ◽  
Vol 47 (11) ◽  
pp. 1053-1061 ◽  
Author(s):  
C. Mavrides ◽  
E. A. Lane
Keyword(s):  
Enzyme Activity ◽  
High Protein Diet ◽  
Tyrosine Aminotransferase ◽  
High Carbohydrate Diet ◽  
Protein Diet ◽  
Carbohydrate Diet ◽  
Hormonal Stimulation ◽  
High Carbohydrate ◽  
Hormonal Effect ◽  
Stimulation Of

The extent of stimulation of rat liver tyrosine aminotransferase by Cortisol and glucagon is inversely proportional to the basal activity of the enzyme in adrenalectomized and hypophysectomized rats. The basal activity is low in animals fed a high-carbohydrate diet leading to high hormonal stimulation of the enzyme, and high in animals fed a high-protein diet leading to minimal or no hormonal stimulation. The dietary modifications of the hormonal effects have been analyzed into two independent processes. Upon short-term starvation, the enzyme activity declines rapidly in animals previously fed a high-protein diet but rises rapidly in animals previously fed a high-carbohydrate diet. Superimposing a positive (hormonal) effect on these two diametrically opposite processes results in profound modification of the hormonal effect on the enzyme activity. The experiments further suggest that the regulation of tyrosine aminotransferase is coupled with gluconeogenic activity per se rather than with a primary hormonal action at the genetic level.

Effect of adrenalectomy and hypophysectomy on responses of rat liver enzymes to high-protein diets

1968 ◽  
Vol 46 (10) ◽  
pp. 1253-1260 ◽  
Author(s):  
R. A. Freedland
Keyword(s):  
Enzyme Activity ◽  
Rat Liver ◽  
Liver Enzymes ◽  
High Protein Diet ◽  
High Protein ◽  
Protein Diet ◽  
Metabolic Function ◽  
Simple Pattern ◽  
High Protein Diets ◽  
Protein Diets

Although many enzymes are increased by either a high-protein diet or cortisol adminstration, there was no evidence of a glucocorticoid requirement for the high-protein mediated increases. This was particularly noticeable for enzymes markedly increased by feeding a high-protein diet. Neither adrenalectomy nor hypophysectomy prevented the diet-mediated increases, although in certain instances the responses were decreased. Many enzymes which were unaffected or decreased in the intact rat by feeding a high-protein diet had markedly different responses after endocrine removal. There did not appear to be a general or simple pattern of these altered responses. Therefore predictions on possible activity changes could not be made, except for those enzymes normally increased by a high-protein diet on the basis of metabolic function or hormonal effects. Possible hormonal controls of these changes in enzyme activity are discussed.

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