scholarly journals Changes in the activity of rat muscle AMP deaminase in relation to the proportion of dietary protein

1974 ◽  
Vol 32 (3) ◽  
pp. 539-548 ◽  
Author(s):  
L. V. Turner ◽  
E. B. Fern
Keyword(s):  
Amino Acid ◽  
Glutamate Dehydrogenase ◽  
Dietary Protein ◽  
Metabolizable Energy ◽  
Amp Deaminase ◽  
Purine Nucleotide ◽  
Alternative Scheme ◽  
Protein Energy ◽  
Purine Nucleotide Cycle ◽  
Nutritional Studies

1. The purine nucleotide cycle has been proposed (Lowenstein, 1972) as an alternative scheme for amino acid deamination in tissues, such as skeletal muscle, having low concentrations of glutamate dehydrogenase (EC 1.4.1.2).2. Activities of AMP deaminase (EC 3.5.4.6), one of the enzymes of the cycle, have been measured in soleus, plantaris and extensor digitorum longus muscles of rats maintained for 18 d on diets providing 0, 0·035 or 0·10 net dietary protein energy (energy supplied by utilizable protein: total metabolizable energy, NDp:E), and in rats given the 0·10 NDp:E diet for 3 d after the 0 or 0·035 NDp:E regimens.3. Concentration of AMP deaminase in the different muscles from the control (0·10 NDp:E diet) rats appeared to bear an inverse relationship to the proportion of mitochondria-rich fibres (i.e. rich in glutamate dehydrogenase) in each muscle.4. Dietary protein deprivation (0 or 0·035 NDp:E) led to adaptive reductions in AMP-deaminase activity in the soleus and plantaris muscles, but in the extensor muscle the 0·035 NDp:E diet produced no change, while the 0 NDp:E diet caused an increase in activity.5. Refeeding the 0·10 NDp:E diet to the protein-deprived rats caused reductions of AMP-deaminase activity to lower levels in all three muscles, except in the instance of soleus in rats refed after the 0·035 NPp:E diet.6. In view of the different responses shown by the three muscles to the dietary treatments, the importance of specifying the particular muscles used in future nutritional studies is emphasized.7. The adaptive changes in AMP deaminase are discussed in terms of operation of the purine nucleotide cycle for amino acid deamination responding to the changes in amino acid catabolism known to be caused in muscle by these protein-deficient diets.

scholarly journals Characteristics of aspartate deamination by the puring nucleotide cycle in the cytosol fraction of rat liver

1975 ◽  
Vol 150 (2) ◽  
pp. 275-283 ◽  
Author(s):  
K M Moss ◽  
J D McGivan
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Nucleoside Triphosphate ◽  
Amp Deaminase ◽  
Purine Nucleotide ◽  
Major Pathway ◽  
Cytosol Fraction ◽  
Purine Nucleotide Cycle

1. The component reactions of the puring nucleotide cycle were studied in cytosol extracts of rat liver. 2. AMP deaminase was strongly activated by ATP and analogues of ATP. 3. IMP was converted into ATP by a system requiring the presence of aspartate, GTP and a nucleoside triphosphate-regenerating system. 4. Under appropriate conditions, NH3 was produced from aspartate. 5. From the rates at which these reactions occur it is concluded that the purine nucleotide cycle may have sufficient activity to be a major pathway of amino acid deamination in liver.

scholarly journals Effects of dietary protein, energy and β-mannanase on laying performance, egg quality, and ileal amino acid digestibility in laying hens.

2021 ◽  
pp. 101312
Author(s):  
Dima White ◽  
Roshan Adhikari ◽  
Jinquan Wang ◽  
Chongxiao Chen ◽  
Jae Hwan Lee ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dietary Protein ◽  
Laying Hens ◽  
Egg Quality ◽  
Protein Energy ◽  
Laying Performance

scholarly journals The effect of protein- and non-protein-nitrogen supplements to maize silage on total amino acid supply in young cattle

1982 ◽  
Vol 48 (3) ◽  
pp. 527-541 ◽  
Author(s):  
B. R. Cottrill ◽  
D. E. Beever ◽  
A. R. Austin ◽  
D. F. Osbourn
Keyword(s):  
Amino Acids ◽  
Small Intestine ◽  
Amino Acid ◽  
Dietary Protein ◽  
Fish Meal ◽  
Metabolizable Energy ◽  
Low Energy ◽  
Maize Silage ◽  
Protein Nitrogen ◽  
Microbial N

1. A total of six diets based on maize silage were formulated to examine the effect of protein- and non-protein-nitrogen, and energy supplementation on the flow of amino acids to the small intestine and the synthesis of microbial amino acids in the rumen of growing cattle. All diets contained 24 g totai nitrogen (N)/kg dry matter (DM), of which 550 g N/kg total N was supplied by either urea or fish meal. Four diets contained low levels of barley (estimated total dietary metabolizable energy content of 10·4 M J/kgDM) and urea-N and fish meal-N were supplied in the ratios 3:1, 1·4:1, 0·6:1 and 0·3:1. The other two diets contained between 300 and 400 g barley/kg total diet (11·3 MJ metabolizable energy/kg DM) and the urea-N to fish meal-N ratios were 3:1 and 0·3:1.2. On the four low-energy diets, fish meal inclusion tended to reduce the extent of organic matter (OM) digestion in the rumen but significantly increased duodenal amino acid supply (P< 0·05) in a quadratic manner. Microbial-N synthesis was increased by the two intermediate levels of fish meal supplementation but declined at the highest level of inclusion. With increasing levels of fish meal inclusion, a greater proportion of the dietary protein was found to escape rumen degradation and the apparent degradabilities of fish meal and maize-silage protein of all four diets were estimated to be 0·22 and 0·73 respectively.3. The substitution of barley for part of the maize silage enhanced duodenal supply of amino acids, irrespective of the form of the N supplement, and stimulated microbial amino acid synthesis. For all diets efficiency of microbial-N synthesis was found to vary between 22·5 and 46 g N/kg rumen-digested OM. Contrary to what was found for low-energy diets, the inclusion of fish meal tended to reduce the flow of dietary protein to the small intestine, but these differences were not statistically significant.4. The results appertaining to microbial synthesis, dietary protein degradabilities and duodenal amino acid flow for all diets are discussed in relation to the Agricultural Research Council (1980) proposals for the protein requirements of ruminants, and the production responses observed when similar diets were fed to growing cattle.

scholarly journals Sources of ammonia for mammalian urea synthesis

1978 ◽  
Vol 176 (3) ◽  
pp. 733-737 ◽  
Author(s):  
H A Krebs ◽  
R Hems ◽  
P Lund ◽  
D Halliday ◽  
W W Read
Keyword(s):  
Glutamate Dehydrogenase ◽  
Initial Rate ◽  
Adenine Nucleotides ◽  
Rat Hepatocytes ◽  
The Other ◽  
Amino Group ◽  
Urea Synthesis ◽  
Purine Nucleotide ◽  
Carbamoyl Phosphate ◽  
Purine Nucleotide Cycle

The initial rate of incorporation of [15N]alanine into the 6-amino group of the adenine nucleotides in rat hepatocytes was about one-eighteenth of the rate of incorporation into urea. Thus the purine nucleotide cycle cannot provide most of the ammonia needed in urea synthesis for the carbamoyl phosphate synthase reaction (EC 2.7.2.5). On the other hand, contrary to the view expressed by McGivan & Chappell [(1975) FEBS Lett. 52, 1–7], the experiments support the view that hepatic glutamate dehydrogenase can supply the required ammonia.

scholarly journals The relationship between glutamate deamination and gluconeogenesis in kidney

1983 ◽  
Vol 210 (3) ◽  
pp. 695-698 ◽  
Author(s):  
R T Bogusky ◽  
L M Lowenstein ◽  
T T Aoki
Keyword(s):  
Glutamate Dehydrogenase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Fold Increase ◽  
Purine Nucleotide ◽  
Single Intraperitoneal Injection ◽  
Purine Nucleotide Cycle ◽  
Kidney Perfusion ◽  
Nh3 Formation ◽  
The Relationship ◽  
Glucose Formation

The effect of 3-mercaptopicolinate, an inhibitor of phosphoenolpyruvate carboxykinase [GTP:oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.32], was tested on NH3 formation via the purine nucleotide cycle and glutamate dehydrogenase (EC 1.4.1.2). NH3 excretion in rats increased 70-fold after 48 h of NH4Cl feeding, from 12.2 +/- 4.5 to 862 +/- 190 mumol/mg of creatinine. At 4 h after a single intraperitoneal injection of 3-mercaptopicolinate into NH4Cl-fed rats, NH3 excretion was inhibited by 93%. Kidneys of NH4Cl-fed plus 3-mercaptopicolinate-treated rats, compared with those of NH4Cl-fed rats, showed a 3.5-fold increase in the content of IMP, 5-fold increase in adenylosuccinate, 4-fold increase in aspartate, and a 30% increase in AMP. 3-Mercaptopicolinate completely inhibited NH3 and glucose formation from glutamate in tubules from acidotic rats and NH3 formation from aspartate in kidney perfusion experiments. When transamination in tubules was prevented by 2-amino-4-methoxy-trans-but-3-enoic acid, formation of glucose, but not of NH3, from glutamate was inhibited. 3-Mercaptopicolinate completely inhibited NH3 formation from aspartate in the presence of the aminotransferase inhibitor in kidney tubules. The data show that NH3 can be formed via glutamate dehydrogenase and the purine nucleotide cycle at significant and approximately equal rates. 3-Mercaptopicolinate has no direct effect on NH3 formation via glutamate dehydrogenase, but inhibits that via the purine nucleotide cycle. We conclude that gluconeogenesis is not regulatory for NH3 formation in kidney.

Ammonia and amino acid metabolism in human skeletal muscle during exercise

1992 ◽  
Vol 70 (1) ◽  
pp. 132-141 ◽  
Author(s):  
T. E. Graham ◽  
D. A. MacLean
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Steady State ◽  
Amino Acid ◽  
Human Skeletal Muscle ◽  
Branched Chain Amino Acids ◽  
Ammonia Production ◽  
Purine Nucleotide ◽  
Purine Nucleotide Cycle ◽  
Branched Chain

This review focuses on the ammonia and amino acid metabolic responses of active human skeletal muscle, with a particular emphasis on steady-state exercise. Ammonia production in skeletal muscle involves the purine nucleotide cycle and the amino acids glutamate, glutamine, and alanine and probably also includes the branched chain amino acids as well as aspartate. Ammonia production is greatest during prolonged, steady state exercise that requires 60–80% [Formula: see text] and is associated with glutamine and alanine metabolism. Under these circumstances it is unresolved whether the purine nucleotide cycle (AMP deamination) is active; if so, it must be cycling with no IMP accumulation. It is proposed that under these circumstances the ammonia is produced from slow twitch fibers by the deamination of the branched chain amino acids. The ammonia response can be suppressed by increasing the carbohydrate availability and this may be mediated by altering the availability of the branched chain amino acids. The fate of the ammonia released into the circulation is unresolved, but there is indirect evidence that a considerable portion may be excreted by the lung in expired air.Key words: glutamine, branched chain amino acids, glutamate dehydrogenase, purine nucleotide cycle.

Effects of different dietary protein‐energy ratios on growth, carcass amino acid and fatty acid profile of male and female Cherax quadricarinatus (von Martens, 1868) pre‐adults

2021 ◽  
Author(s):  
Yuniel Méndez‐Martínez ◽  
Carlos Ernesto Ceseña ◽  
Antonio Luna‐González ◽  
Marcelo U. García‐Guerrero ◽  
Marcel Martinez‐Porchas ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Amino Acid ◽  
Fatty Acid Profile ◽  
Dietary Protein ◽  
Male And Female ◽  
Cherax Quadricarinatus ◽  
Protein Energy ◽  
Energy Ratios

scholarly journals The purine nucleotide cycle in the regulation of ammoniagenesis during induction and cessation of chronic acidosis in the rat kidney

1981 ◽  
Vol 196 (1) ◽  
pp. 323-326 ◽  
Author(s):  
R T Bogusky ◽  
K A Steele ◽  
L M Lowenstein
Keyword(s):  
Glutamate Dehydrogenase ◽  
Rat Kidney ◽  
Recovery Period ◽  
Purine Nucleotide ◽  
Sprague Dawley ◽  
Metabolic Intermediates ◽  
Control Value ◽  
Sprague Dawley Rats ◽  
Purine Nucleotide Cycle ◽  
Subsequent Withdrawal

The effect of chronic acid feeding and its subsequent withdrawal was determined on the amounts of the metabolic intermediates and enzymic activities of the purine nucleotide cycle. Sprague-Dawley rats were given 1.5% (w/v) NH4Cl in their drinking water for 5 days. The renal excretion of NH3 rose 70-fold and the rats developed acidosis. The amount of renal IMP rose from a control value of 4.5 +/- 2.2 to 20.4 +/- 3.7nmol/g of kidney after 48h of acid feeding (P less than 0.001) and fell to normal within 48h of the recovery. Adenylosuccinate concentrations fell from a control value of 4.5 +/- 0.9nmol/g of kidney to 1.2 +/- 0.3nmol/g (P less than 0.005) by day 5 of acidosis and continued to fall to undetectable values by 48h after recovery. The amount of AMP remained constant through the acid-feeding and the recovery periods. The activity of adenylosuccinate synthetase, the rate-limiting enzyme of the purine nucleotide cycle, paralleled the rise and fall in NH3 excretion. The activities of phosphate-dependent glutaminase and glutamate dehydrogenase were elevated during the acid-feeding and the recovery period. Thus changes in the purine nucleotide cycle correlate with changes in NH3 excretion to a more parallel degree than does the activity of glutaminase or glutamate dehydrogenase.

scholarly journals Dietary protein level alters oxidative phosphorylation in heart and liver mitochondria of chicks

1992 ◽  
Vol 68 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Masaaki Toyomizu ◽  
Daisuke Kirihara ◽  
Masahiro Tanaka ◽  
Kunioki Hayashi ◽  
Yuichiro Tomita
Keyword(s):  
Oxidative Phosphorylation ◽  
Body Fat ◽  
Dietary Protein ◽  
Protein Level ◽  
Mitochondrial Protein ◽  
Liver Mitochondria ◽  
Metabolizable Energy ◽  
Mitochondrial Oxidative Phosphorylation ◽  
Dietary Protein Level ◽  
Protein Energy

To determine the effects of dietary protein level on cardiac and hepatic mitochondrial oxidative phosphorylation, chicks were fed on semi-purified diets of different protein levels (7, 25, 43 and 61% of metabolizable energy content) for 7, 14 and 21 d. All diets were formulated to contain equivalent fat, mineral and vitamin contents on a gross energy basis. Cardiac and hepatic mitochondrial oxidative phosphorylation rates were assessed polarographically with pyruvate and malate as substrates. Cardiac mitochondria isolated from chicks fed on a 43 or 61% protein-energy diet for 7 d exhibited significantly reduced ADP:oxygen (ADP:O) ratios when compared with mitochondria isolated from chicks fed on a lower-protein-energy diet. Feeding low- (7%) protein-energy diets for 14 d resulted in a relatively increased ADP:O ratio in the heart. Responses of ADP:O ratios to protein level in hepatic mitochondria showed more dependency on protein level than in heart muscle; at all feeding periods the ADP:O ratio decreased with an increase in protein level. As a result, ATP synthesized in the liver, expressed as nmol/mg mitochondrial protein per min, significantly decreased with increased dietary protein level. A parallel correlation was observed, in chicks fed on diets with different levels of protein, between ADP:O ratio for liver mitochondria and body fat. These results suggest that the reduction in oxidative phosphorylation in the heart and liver of animals fed on a higher protein-energy diet may partly contribute to the depression of body fat.

scholarly journals Tissue- and substrate-dependent responses of oxidative phosphorylation to dietary protein level in chicks

1993 ◽  
Vol 70 (2) ◽  
pp. 459-469 ◽  
Author(s):  
Masahiro Tanaka ◽  
Teru Ishibashi ◽  
Katsuyuki Okamoto ◽  
Masaaki Toyomizu
Keyword(s):  
Oxidative Phosphorylation ◽  
Dietary Protein ◽  
Protein Level ◽  
Skeletal Muscles ◽  
Energy Content ◽  
Electron Flow ◽  
Liver Mitochondria ◽  
Metabolizable Energy ◽  
Protein Levels ◽  
Protein Energy

The ADP:O values in both cardiac and hepatic mitochondria have significantly decreased with an increase in protein level after 7, 14 and 21 d of feeding (Toyomizu et al. 1992). The present studies were undertaken to clarify tissue-specific effects of dietary protein levels on oxidative phosphorylation in the liver, kidney, skeletal muscles and small intestine and to characterize oxidative metabolism with diverse substrates in the liver. Chicks were fed on semi-purified diets of different protein levels (7, 25, 43 and 61% of metabolizable energy content) for 21 d. The responses of protein levels to oxidative phosphorylation showed tissue-dependency; although liver mitochondria of chickens fed on higher- protein diets exhibited reduced ADP:O values and state 3, neither changes in ADP:O value nor state 3 and state 4 rates were observed in the isolated mitochondria from kidney and skeletal muscles. Small intestinal mucosal mitochondria from chickens fed on a high (61%)-protein-energy diet showed significantly reduced ADP:O value and respiratory control ratio when compared with medium-protein- energy diets (25 and 43%). In liver mitochondria showing the most sensitive dependency to the levels of dietary protein, the ADP:O value decreased with increasing protein levels when pyruvate + malate- or glutamate-requiring complexes I, III and IV of the electron transport chain were used as substrates, but it did not change when succinate-requiring complexes II, III and IV or ascorbate + tetramethyl-p- phenylenediamine requiring complex IV was used. These results imply that impaired oxidative phosphorylation capacities with increasing dietary protein levels may be associated with functional damage to the respiratory chain for electron flow from NAD-linked substrates to the ubiquinone pool.

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