scholarly journals Glycolytic origin of alanine formed in rat diaphragm muscle in vitro

1985 ◽  
Vol 231 (3) ◽  
pp. 801-804 ◽  
Author(s):  
M A Caldecourt ◽  
D J Cox ◽  
M C Sugden ◽  
T N Palmer
Keyword(s):  
Amino Acids ◽  
De Novo ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Acid Cycle ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Alanine Production

In quarter-diaphragms from 40 h-starved rats the rate of glycogen mobilization is sufficient to account for the rate of lactate+pyruvate+alanine production. It is concluded, therefore, that alanine derives its carbon skeleton predominantly via glycolysis and not via synthesis de novo from tricarboxylic acid-cycle intermediates and related amino acids.

scholarly journals Metabolic phases during the development of granulation tissue

1967 ◽  
Vol 105 (1) ◽  
pp. 333-341 ◽  
Author(s):  
Kirsti Lampiaho ◽  
E. Kulonen
Keyword(s):  
Granulation Tissue ◽  
Collagen Synthesis ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Pentose Phosphate ◽  
Acid Cycle ◽  
Short Period ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Observation Period

1. The metabolism of incubated slices of sponge-induced granulation tissue, harvested 4–90 days after the implantation, was studied with special reference to the capacity of collagen synthesis and to the energy metabolism. Data are also given on the nucleic acid contents during the observation period. Three metabolic phases were evident. 2. The viability of the slices for the synthesis of collagen was studied in various conditions. Freezing and homogenization destroyed the capacity of the tissue to incorporate proline into collagen. 3. Consumption of oxygen reached the maximum at 30–40 days. There was evidence that the pentose phosphate cycle was important, especially during the phases of the proliferation and the involution. The formation of lactic acid was maximal at about 20 days. 4. The capacity to incorporate proline into collagen hydroxyproline in vitro was limited to a relatively short period at 10–30 days. 5. The synthesis of collagen was dependent on the supply of oxygen and glucose, which latter could be replaced in the incubation medium by other monosaccharides but not by the metabolites of glucose or tricarboxylic acid-cycle intermediates.

scholarly journals Studies on the Metabolism of Locust Fat Body

1959 ◽  
Vol 36 (4) ◽  
pp. 665-675
Author(s):  
A. N. CLEMENTS
Keyword(s):  
Amino Acids ◽  
Sodium Acetate ◽  
Flight Muscle ◽  
Fat Body ◽  
Enzyme System ◽  
Tricarboxylic Acid Cycle ◽  
Succinic Dehydrogenase ◽  
Tricarboxylic Acid ◽  
Acid Cycle

1. The incorporation of glycine-14C (G), leucine-14C (G), sodium acetate-2-14C and glucose-14C (G) into Schistocerca fat body was studied under in vitro conditions, and the distribution of radioactivity in the various fat body fractions and the labelling of compounds within the fractions is described. 2. The overall picture was of high incorporation into fat and protein and of very low incorporation into glycogen. 3. Incubation with glycine-14C led to radioactivity appearing in the glycine and serine of the protein and of the amino acid pool. Incubation with sodium acetate-2-14C led to radioactivity appearing in glutamate, proline, aspartate and alanine, showing that the intermediates of the tricarboxylic acid cycle provide the carbon skeletons of certain amino acids. Glucose-14C was largely converted to trehalose. 4. Succinic dehydrogenase and the condensing enzyme system were shown to be present in fat body, contrary to previous reports. The succinic oxidase system was highly labile on homogenizing the tissue. 5. Fat body, unlike flight muscle, used glycine-14C and leucine-14C as respiratory substrates, and it is suggested that fat body acts like the vertebrate liver by transdeaminating amino acids and making them available for further metabolism by other tissues.

C14-labeled glucose metabolism by bone from normal and parathyroid-treated rats

1965 ◽  
Vol 208 (5) ◽  
pp. 1036-1041 ◽  
Author(s):  
Haripada Chattopadhyay ◽  
Smith Freeman
Keyword(s):  
Glucose Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Bone Matrix ◽  
Tricarboxylic Acid ◽  
Bicarbonate Buffer ◽  
Acid Cycle ◽  
Growing Rats ◽  
Parathyroid Extract ◽  
Tricarboxylic Acid Cycle Intermediates

Calvaria and the metaphyseal and epiphyseal sections of tibia and femora freed of bone marrow from young growing rats were incubated in vitro for 2 hr at 37 C in Krebs-Ringer bicarbonate buffer containing 2 mm glucose. The glucose was labeled either in the 1 position or in the 6 position or uniformly in all positions with C14. The incorporation of C14 into citrate, lactate, and various tricarboxylic acid cycle intermediates was studied. The release of C14O2 and the incorporation of C14 into bone matrix were also measured. Results obtained from bones of untreated control, parathyroid extract-treated, and parathyroidectomized animals were compared. It was found that treatment of animals with parathyroid extract increased the total accumulation of labeled citrate and malate as well as the incorporation of these acids into bone mineral. Bones from extract-treated animals also exhibited a significant decrease in the total accumulation of radioactive fumarate, succinate, and pyruvate. Lactate was the major end product of glucose metabolism, but its accumulation was only slightly influenced by parathyroid extract.

scholarly journals Effects of insulin on the pattern of glucose metabolism in the perfused working and Lagendorff heart of normal and insulin-deficient rats

1969 ◽  
Vol 115 (3) ◽  
pp. 537-546 ◽  
Author(s):  
E B Chain ◽  
K. R. L. Mansford ◽  
L. H. Opie
Keyword(s):  
Glucose Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Work Load ◽  
Tricarboxylic Acid ◽  
Diaphragm Muscle ◽  
Perfusion Fluid ◽  
Acid Cycle ◽  
14Co2 Production ◽  
Tricarboxylic Acid Cycle Intermediates ◽  
Phosphorylated Sugars

1. The metabolic pattern of [U−14C]glucose in the isolated rat heart has been studied, with both retrograde aortic (Langendorff) and atrially (working) perfused preparations in the presence and absence of insulin, in normal animals, animals rendered insulin-deficient (by injection of anti-insulin serum 1hr. before excision of the heart) and animals rendered diabetic by streptozotocin injection 7 days before use. 2. Radioautochromatograms of heart extracts show that the pattern of glucose metabolism in heart muscle is more complex than in diaphragm muscle. In addition to 14CO2, glycogen, oligosaccharides, phosphorylated sugars and lactate (the main metabolites formed from [14C]glucose in diaphragm muscle), 14C label from [14C]glucose appears in heart muscle in glutamate, glutamine, aspartate and alanine, and in tricarboxylic acid-cycle intermediates. 3. By a quantitative scanning technique of two-dimensional chromatograms it was found that a mechanical work load stimulates glucose metabolism, increasing by a factor of 2–3 incorporation of 14C into all the metabolites mentioned above except lactate and phosphorylated sugars, into which 14C incorporation is in fact diminished; 14CO2 production is equally stimulated. 4. Addition of insulin to the perfusion fluid of the working heart causes increases in 14C incorporation, by a factor of about 1·5 into 14CO2, by a factor of about 3–5 into glycogen, lactate and phosphorylated sugars, by a factor of about 2–3 into glutamate and tricarboxylic acid-cycle intermediates and by a factor of about 0·5 into aspartate, whereas incorporation into alanine and glutamine is not affected. The effect of a work load on the pattern of glucose metabolism is thus different from that of insulin. 5. Increasing the concentration of glucose in the perfusion fluid from 1 to 20mm leads to changes of the pattern of glucose metabolism different from that brought about by insulin. 14CO2 production steadily increases whereas [14C]lactate and glycogen production levels off at 10mm-glucose, at values well below those reached in the presence of insulin. 6. In Langendorff hearts of animals rendered insulin-deficient by anti-insulin serum or streptozotocin, glucose uptake, formation of 14CO2 and [14C]lactate, and 14C incorporation into glycogen and oligosaccharides are decreased. In insulin-deficient working hearts, however, glucose uptake and 14CO2 production are normal, whereas incorporation of 14C into glycogen and [14C]lactate production are greatly decreased. 7. Insulin added to the perfusion fluid restores 14C incorporation from glucose into 14CO2, glycogen and lactate in the Langendorff heart from animals rendered insulin-deficient by anti-insulin serum; in hearts from streptozotocin-diabetic animals addition of insulin restores 14C incorporation into glycogen and lactate, but 14CO2 production remains about 50% below normal. 8. The bearing of these results on the problem of the mode of action of insulin is discussed.

scholarly journals Effects of denervation on the activities of some tricarboxylic acid-cycle-associated dehydrogenases and adenine-metabolizing enzymes in rat diaphragm muscle

1972 ◽  
Vol 128 (4) ◽  
pp. 803-809 ◽  
Author(s):  
L. V. Turner ◽  
K. L. Manchester
Keyword(s):  
Glutathione Reductase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Diaphragm Muscle ◽  
Rat Diaphragm ◽  
Nerve Section ◽  
Metabolizing Enzymes ◽  
Acid Cycle ◽  
Red Muscle ◽  
Left And Right

1. The activity of several tricarboxylic acid-cycle-associated dehydrogenases, adenine-metabolizing enzymes and glutathione reductase and the content of myoglobin were measured in rat diaphragm muscle after unilateral nerve section. 2. Consistent with morphological disintegration of the mitochondria there was a rapid diminution in activity of NAD- and NADP-linked isocitrate dehydrogenase, malate dehydrogenase and glutamate dehydrogenase. 3. Creatine phosphokinase and adenylate kinase, by contrast, showed little change in activity; adenylate deaminase and glutathione reductase activities increased during the hypertrophic phase. The concentration of myoglobin at first declined, then increased again. 4. The distribution of enzymes between the left and right hemidiaphragms was found not to be uniform. 5. Activities of adenine-metabolizing enzymes in the diaphragm were as great as in white muscle. It is suggested that their reputedly lower activities in red muscle properly refer to muscle containing a high proportion of intermediate fibres, which is not the case with diaphragm. 6. The possible causes of the transient hypertrophy after nerve section are discussed.

scholarly journals Chemotaxis of Silicibacter sp. Strain TM1040 toward Dinoflagellate Products

2004 ◽  
Vol 70 (8) ◽  
pp. 4692-4701 ◽  
Author(s):  
Todd R. Miller ◽  
Kristin Hnilicka ◽  
Amanda Dziedzic ◽  
Paula Desplats ◽  
Robert Belas
Keyword(s):  
Amino Acids ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Chemotactic Response ◽  
Organosulfur Compounds ◽  
Screening Assay ◽  
Acid Cycle ◽  
Exogenous Addition ◽  
Pure Compounds ◽  
Tricarboxylic Acid Cycle Intermediates

ABSTRACT The α-proteobacteria phylogenetically related to the Roseobacter clade are predominantly responsible for the degradation of organosulfur compounds, including the algal osmolyte dimethylsulfoniopropionate (DMSP). Silicibacter sp. strain TM1040, isolated from a DMSP-producing Pfiesteria piscicida dinoflagellate culture, degrades DMSP, producing 3-methylmercaptopropionate. TM1040 possesses three lophotrichous flagella and is highly motile, leading to a hypothesis that TM1040 interacts with P. piscicida through a chemotactic response to compounds produced by its dinoflagellate host. A combination of a rapid chemotaxis screening assay and a quantitative capillary assay were used to measure chemotaxis of TM1040. These bacteria are highly attracted to dinoflagellate homogenates; however, the response decreases when homogenates are preheated to 80°C. To help identify the essential attractant molecules within the homogenates, a series of pure compounds were tested for their ability to serve as attractants. The results show that TM1040 is strongly attracted to amino acids and DMSP metabolites, while being only mildly responsive to sugars and the tricarboxylic acid cycle intermediates. Adding pure DMSP, methionine, or valine to the chemotaxis buffer resulted in a decreased response to the homogenates, indicating that exogenous addition of these chemicals blocks chemotaxis and suggesting that DMSP and amino acids are essential attractant molecules in the dinoflagellate homogenates. The implication of Silicibacter sp. strain TM1040 chemotaxis in establishing and maintaining its interaction with P. piscicida is discussed.

scholarly journals Triheptanoin partially restores levels of tricarboxylic acid cycle intermediates in the mouse pilocarpine model of epilepsy

2013 ◽  
Vol 129 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Mussie G. Hadera ◽  
Olav B. Smeland ◽  
Tanya S. McDonald ◽  
Kah Ni Tan ◽  
Ursula Sonnewald ◽  
...  
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Pilocarpine Model ◽  
Tricarboxylic Acid Cycle Intermediates
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