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Articoli di riviste sul tema "Pyruvate"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 14 marzo 2023

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1

Mallet, Robert T., Jie Sun, E. Marty Knott, Arti B. Sharma e Albert H. Olivencia-Yurvati. "Metabolic Cardioprotection by Pyruvate: Recent Progress". Experimental Biology and Medicine 230, n. 7 (luglio 2005): 435–43. http://dx.doi.org/10.1177/153537020523000701.

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Pyruvate, a natural metabolic fuel and antioxidant in myocardium and other tissues, exerts a variety of cardioprotective actions when provided at supraphysiological concentrations. Pyruvate increases cardiac contractile performance and myocardial energy state, bolsters endogenous antioxidant systems, and protects myocardium from ischemia-reperfusion injury and oxidant stress. This article reviews and discusses basic and clinically oriented research conducted over the last several years that has yielded fundamental information on pyruvate's inotropic and cardioprotective mechanisms. Particular attention is placed on pyruvate's enhancement of sarcoplasmic reticular Ca2+ transport, its antioxidant properties, and its ability to mitigate reversible and irreversible myocardial injury. These research efforts are establishing the essential foundation for clinical application of pyruvate therapy in numerous settings including cardiopulmonary bypass surgery, cardiopulmonary resuscitation, myocardial stunning, and cardiac failure.

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2

Mallet, Robert T., Albert H. Olivencia-Yurvati e Rolf Bünger. "Pyruvate enhancement of cardiac performance: Cellular mechanisms and clinical application". Experimental Biology and Medicine 243, n. 2 (20 novembre 2017): 198–210. http://dx.doi.org/10.1177/1535370217743919.

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Cardiac contractile function is adenosine-5'-triphosphate (ATP)-intensive, and the myocardium’s high demand for oxygen and energy substrates leaves it acutely vulnerable to interruptions in its blood supply. The myriad cardioprotective properties of the natural intermediary metabolite pyruvate make it a potentially powerful intervention against the complex injury cascade ignited by myocardial ischemia–reperfusion. A readily oxidized metabolic substrate, pyruvate augments myocardial free energy of ATP hydrolysis to a greater extent than the physiological fuels glucose, lactate and fatty acids, particularly when it is provided at supra-physiological plasma concentrations. Pyruvate also exerts antioxidant effects by detoxifying reactive oxygen and nitrogen intermediates, and by increasing nicotinamide adenine dinucleotide phosphate reduced form (NADPH) production to maintain glutathione redox state. These enhancements of free energy and antioxidant defenses combine to augment sarcoplasmic reticular Ca2+ release and re-uptake central to cardiac mechanical performance and to restore β-adrenergic signaling of ischemically stunned myocardium. By minimizing Ca2+ mismanagement and oxidative stress, pyruvate suppresses inflammation in post-ischemic myocardium. Thus, pyruvate administration stabilized cardiac performance, augmented free energy of ATP hydrolysis and glutathione redox systems, and/or quelled inflammation in a porcine model of cardiopulmonary bypass, a canine model of cardiac arrest–resuscitation, and a caprine model of hypovolemia and hindlimb ischemia–reperfusion. Pyruvate’s myriad benefits in preclinical models provide the mechanistic framework for its clinical application as metabolic support for myocardium at risk. Phase one trials have demonstrated pyruvate’s safety and efficacy for intravenous resuscitation for septic shock, intracoronary infusion for heart failure and as a component of cardioplegia for cardiopulmonary bypass. The favorable outcomes of these trials, which argue for expanded, phase three investigations of pyruvate therapy, mirror findings in isolated, perfused hearts, underscoring the pivotal role of preclinical research in identifying clinical interventions for cardiovascular diseases. Impact statement This article reviews pyruvate’s cardioprotective properties as an energy-yielding metabolic fuel, antioxidant and anti-inflammatory agent in mammalian myocardium. Preclinical research has shown these properties make pyruvate a powerful intervention to curb the complex injury cascade ignited by ischemia and reperfusion. In ischemically stunned isolated hearts and in large mammal models of cardiopulmonary bypass, cardiac arrest–resuscitation and hypovolemia, intracoronary pyruvate supports recovery of myocardial contractile function, intracellular Ca2+ homeostasis and free energy of ATP hydrolysis, and its antioxidant actions restore β-adrenergic signaling and suppress inflammation. The first clinical trials of pyruvate for cardiopulmonary bypass, fluid resuscitation and intracoronary intervention for congestive heart failure have been reported. Receiver operating characteristic analyses show remarkable concordance between pyruvate’s beneficial functional and metabolic effects in isolated, perfused hearts and in patients recovering from cardiopulmonary bypass in which they received pyruvate- vs. L-lactate-fortified cardioplegia. This research exemplifies the translation of mechanism-oriented preclinical studies to clinical application and outcomes.

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3

Abysalamah, Hazzar M. "Sodium Pyruvate Alters the Immune Response to Influenza A Virus Infection in Macrophages". Journal of Immunology 200, n. 1_Supplement (1 maggio 2018): 108.21. http://dx.doi.org/10.4049/jimmunol.200.supp.108.21.

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Abstract Pyruvate is the end product of glycolysis. It can either be transported into the mitochondria for use in the TCA cycle or be used to regenerate NAD+ during aerobic glycolysis. We recently discovered that addition of sodium pyruvate to the culture medium during infection of macrophages with influenza A virus affects the production of cytokines involved in immune signaling. The purpose of the present study was to determine whether sodium pyruvate’s role in energy production in the macrophages may alter the immune response to the infection. While infection of macrophages with influenza A virus resulted in high levels of cytokines (IL-6, IL-1β, and TNF-α) in the absence of sodium pyruvate, the addition of sodium pyruvate significantly impaired cytokine production. Furthermore, sodium pyruvate did not affect virus growth, suggesting the effect of sodium pyruvate is on the immune response produced by the macrophages and not the viability of the virus.

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4

Reel, Jessica M., e Christopher R. Lupfer. "Sodium Pyruvate Ameliorates Influenza a Virus Infection In Vivo". Microbiology Research 12, n. 2 (26 marzo 2021): 258–67. http://dx.doi.org/10.3390/microbiolres12020018.

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Influenza A virus (IAV) causes seasonal epidemics annually and pandemics every few decades. Most antiviral treatments used for IAV are only effective if administered during the first 48 h of infection and antiviral resistance is possible. Therapies that can be initiated later during IAV infection and that are less likely to elicit resistance will significantly improve treatment options. Pyruvate, a key metabolite, and an end product of glycolysis, has been studied for many uses, including its anti-inflammatory capabilities. Sodium pyruvate was recently shown by us to decrease inflammasome activation during IAV infection. Here, we investigated sodium pyruvate’s effects on IAV in vivo. We found that nebulizing mice with sodium pyruvate decreased morbidity and weight loss during infection. Additionally, treated mice consumed more chow during infection, indicating improved symptoms. There were notable improvements in pro-inflammatory cytokine production (IL-1β) and lower virus titers on day 7 post-infection in mice treated with sodium pyruvate compared to control animals. As pyruvate acts on the host immune response and metabolic pathways and not directly on the virus, our data demonstrate that sodium pyruvate is a promising treatment option that is safe, effective, and unlikely to elicit antiviral resistance.

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5

&NA;. "Pyruvate". Reactions Weekly &NA;, n. 376 (novembre 1991): 7–8. http://dx.doi.org/10.2165/00128415-199103760-00042.

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6

Vassault, Anne. "Pyruvate". EMC - Biologie Médicale 1, n. 3 (gennaio 2006): 1–3. http://dx.doi.org/10.1016/s2211-9698(06)76497-4.

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7

Priestman, David A., Karen A. Orfali e Mary C. Sugden. "Pyruvate inhibition of pyruvate dehydrogenase kinase". FEBS Letters 393, n. 2-3 (16 settembre 1996): 174–78. http://dx.doi.org/10.1016/0014-5793(96)00877-0.

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8

Hasona, Adnan, Youngnyun Kim, F. G. Healy, L. O. Ingram e K. T. Shanmugam. "Pyruvate Formate Lyase and Acetate Kinase Are Essential for Anaerobic Growth of Escherichia coli on Xylose". Journal of Bacteriology 186, n. 22 (15 novembre 2004): 7593–600. http://dx.doi.org/10.1128/jb.186.22.7593-7600.2004.

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ABSTRACT During anaerobic growth of bacteria, organic intermediates of metabolism, such as pyruvate or its derivatives, serve as electron acceptors to maintain the overall redox balance. Under these conditions, the ATP needed for cell growth is derived from substrate-level phosphorylation. In Escherichia coli, conversion of glucose to pyruvate yields 2 net ATPs, while metabolism of a pentose, such as xylose, to pyruvate only yields 0.67 net ATP per xylose due to the need for one (each) ATP for xylose transport and xylulose phosphorylation. During fermentative growth, E. coli produces equimolar amounts of acetate and ethanol from two pyruvates, and these reactions generate one additional ATP from two pyruvates (one hexose equivalent) while still maintaining the overall redox balance. Conversion of xylose to acetate and ethanol increases the net ATP yield from 0.67 to 1.5 per xylose. An E. coli pfl mutant lacking pyruvate formate lyase cannot convert pyruvate to acetyl coenzyme A, the required precursor for acetate and ethanol production, and could not produce this additional ATP. E. coli pfl mutants failed to grow under anaerobic conditions in xylose minimal medium without any negative effect on their survival or aerobic growth. An ackA mutant, lacking the ability to generate ATP from acetyl phosphate, also failed to grow in xylose minimal medium under anaerobic conditions, confirming the need for the ATP produced by acetate kinase for anaerobic growth on xylose. Since arabinose transport by AraE, the low-affinity, high-capacity, arabinose/H+ symport, conserves the ATP expended in pentose transport by the ABC transporter, both pfl and ackA mutants grew anaerobically with arabinose. AraE-based xylose transport, achieved after constitutively expressing araE, also supported the growth of the pfl mutant in xylose minimal medium. These results suggest that a net ATP yield of 0.67 per pentose is only enough to provide for maintenance energy but not enough to support growth of E. coli in minimal medium. Thus, pyruvate formate lyase and acetate kinase are essential for anaerobic growth of E. coli on xylose due to energetic constraints.

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9

El-Harairy, Ahmed, Mennatallah Shaheen, Jun Li, Yuzhou Wu, Minghao Li e Yanlong Gu. "Synthesis of α-indolylacrylates as potential anticancer agents using a Brønsted acid ionic liquid catalyst and the butyl acetate solvent". RSC Advances 10, n. 23 (2020): 13507–16. http://dx.doi.org/10.1039/d0ra00990c.

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4lNew α-indolylacrylate derivatives were synthesized by reaction of 2-substituted indoles with various pyruvates using a Brønsted acid ionic liquid catalyst in butyl acetate solvent. This is the first application of pyruvate compounds for the synthesis of indolylacrylates.

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10

Max-Audit, Isabelle. "Pyruvate kinase". EMC - Biologie Médicale 1, n. 3 (gennaio 2006): 1–4. http://dx.doi.org/10.1016/s2211-9698(06)76498-6.

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11

Wallace, J. C., S. Jitrapakdee e A. Chapman-Smith. "Pyruvate carboxylase". International Journal of Biochemistry & Cell Biology 30, n. 1 (marzo 1998): 1–5. http://dx.doi.org/10.1016/s1357-2725(97)00147-7.

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12

Scrutton, M. C. "Pyruvate carboxylase". FEBS Letters 206, n. 1 (29 settembre 1986): 169–70. http://dx.doi.org/10.1016/0014-5793(86)81365-5.

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13

Fink, Mitchell P. "Ethyl pyruvate". Current Opinion in Anaesthesiology 21, n. 2 (aprile 2008): 160–67. http://dx.doi.org/10.1097/aco.0b013e3282f63c2e.

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14

Tullu, Milind S., Ankita A. Kulkarni e Mukesh Agrawal. "Pyruvate Kinase Deficiency: A Near Miss". Indian Journal of Trauma and Emergency Pediatrics 11, n. 2 (2019): 41–44. http://dx.doi.org/10.21088/ijtep.2348.9987.11219.3.

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15

Treu, Becky L., Daria Sokic-Lazic e Shelley Minteer. "Bioelectrocatalysis of Pyruvate with PQQ-dependent Pyruvate Dehydrogenase". ECS Transactions 25, n. 28 (17 dicembre 2019): 1–11. http://dx.doi.org/10.1149/1.3309672.

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16

MOTONAKA, Junko, Kazuhisa MIYATA e Sanae IKEDA. "Pyruvate Sensor Based on Tetradecylammonium Pyruvate Ion-pair". Denki Kagaku oyobi Kogyo Butsuri Kagaku 64, n. 12 (5 dicembre 1996): 1341–44. http://dx.doi.org/10.5796/kogyobutsurikagaku.64.1341.

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17

Mascini, M., e F. Mazzei. "Amperometric sensor for pyruvate with immobilized pyruvate oxidase". Analytica Chimica Acta 192 (1987): 9–16. http://dx.doi.org/10.1016/s0003-2670(00)85683-4.

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18

Sugden, Mary C., e Mark J. Holness. "The pyruvate carboxylase-pyruvate dehydrogenase axis in islet pyruvate metabolism: Going round in circles?" Islets 3, n. 6 (novembre 2011): 302–19. http://dx.doi.org/10.4161/isl.3.6.17806.

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19

Kerbey, A. L., e P. J. Randle. "Pyruvate dehydrogenase kinase activity of pig heart pyruvate dehydrogenase (E1 component of pyruvate dehydrogenase complex)". Biochemical Journal 231, n. 3 (1 novembre 1985): 523–29. http://dx.doi.org/10.1042/bj2310523.

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The pyruvate dehydrogenase (E1) and acetyltransferase (E2) components of pig heart and ox kidney pyruvate dehydrogenase (PDH) complex were separated and purified. The E1 component was phosphorylated (alpha-chain) and inactivated by MgATP. Phosphorylation was mainly confined to site 1. Addition of E2 accelerated phosphorylation of all three sites in E1 alpha and inactivation of E1. On the basis of histone H1 phosphorylation, E2 is presumed to contain PDH kinase, which was removed (greater than 98%) by treatment with p-hydroxymercuriphenylsulphonate. Stimulation of ATP-dependent inactivation of E1 by E2 was independent of histone H1 kinase activity of E2. The effect of E2 is attributed to conformational change(s) induced in E1 and/or E1-associated PDH kinase. PDH kinase activity associated with E1 could not be separated from it be gel filtration or DEAE-cellulose chromatography. Subunits of PDH kinase were not detected on sodium dodecyl sulphate/polyacrylamide gels of E1 or E2, presumably because of low concentration. The activity of pig heart PDH complex was increased by E2, but not by E1, indicating that E2 is rate-limiting in the holocomplex reaction. ATP-dependent inactivation of PDH complex was accelerated by E1 or by phosphorylated E1 plus associated PDH kinase, but not by E2 plus presumed PDH kinase. It is suggested that a substantial proportion of PDH kinase may accompany E1 when PDH complex is dissociated into its component enzymes. The possibility that E1 may possess intrinsic PDH kinase activity is considered unlikely, but may not have been fully excluded.

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20

Robinson, Brian H., e Kathy Chun. "The relationships between transketolase, yeast pyruvate decarboxylase and pyruvate dehydrogenase of the pyruvate dehydrogenase complex". FEBS Letters 328, n. 1-2 (9 agosto 1993): 99–102. http://dx.doi.org/10.1016/0014-5793(93)80973-x.

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21

Eram, Mohammad S., Erica Oduaran e Kesen Ma. "The Bifunctional Pyruvate Decarboxylase/Pyruvate Ferredoxin Oxidoreductase fromThermococcus guaymasensis". Archaea 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/349379.

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The hyperthermophilic archaeonThermococcus guaymasensisproduces ethanol as a metabolic end product, and an alcohol dehydrogenase (ADH) catalyzing the reduction of acetaldehyde to ethanol has been purified and characterized. However, the enzyme catalyzing the formation of acetaldehyde has not been identified. In this study an enzyme catalyzing the production of acetaldehyde from pyruvate was purified and characterized fromT. guaymasensisunder strictly anaerobic conditions. The enzyme had both pyruvate decarboxylase (PDC) and pyruvate ferredoxin oxidoreductase (POR) activities. It was oxygen sensitive, and the optimal temperatures were 85°C and >95°C for the PDC and POR activities, respectively. The purified enzyme had activities of3.8±0.22 U mg−1and20.2±1.8 U mg−1, with optimal pH-values of 9.5 and 8.4 for each activity, respectively. Coenzyme A was essential for both activities, although it did not serve as a substrate for the former. Enzyme kinetic parameters were determined separately for each activity. The purified enzyme was a heterotetramer. The sequences of the genes encoding the subunits of the bifunctional PDC/POR were determined. It is predicted that all hyperthermophilicβ-keto acids ferredoxin oxidoreductases are bifunctional, catalyzing the activities of nonoxidative and oxidative decarboxylation of the correspondingβ-keto acids.

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22

Robinson, B. H., N. MacKay, K. Chun e M. Ling. "Disorders of pyruvate carboxylase and the pyruvate dehydrogenase complex". Journal of Inherited Metabolic Disease 19, n. 4 (luglio 1996): 452–62. http://dx.doi.org/10.1007/bf01799106.

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23

Jones, C. G., S. K. Hothi e M. A. Titheradge. "Effect of dexamethasone on gluconeogenesis, pyruvate kinase, pyruvate carboxylase and pyruvate dehydrogenase flux in isolated hepatocytes". Biochemical Journal 289, n. 3 (1 febbraio 1993): 821–28. http://dx.doi.org/10.1042/bj2890821.

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Treatment of 18 h-starved rats with dexamethasone and subsequent isolation and incubation of the hepatocytes in the presence of the steroid increased gluconeogenic flux with both 1.0 mM pyruvate and 1.0 mM lactate plus 0.2 mM pyruvate as the substrate. The magnitude of stimulation was comparable with both substrates. The increase in glucose output was accompanied by an increased flux through pyruvate carboxylase, although the absolute flux and magnitude were considerably less in the presence of the more reduced substrate. The effect of the steroid on the flux through pyruvate dehydrogenase was substrate-dependent, an inhibition occurring with the more oxidized substrate. There was no effect of steroid treatment on [1-14C]lactate or pyruvate oxidation or on tricarboxylic-acid-cycle flux as measured by [3-14C]pyruvate oxidation. Dexamethasone treatment resulted in a parallel increase in both pyruvate kinase flux and glucose synthesis with both substrates employed, indicating that the steroid had no effect on the partitioning of phosphoenolpyruvate between pyruvate and lactate formation and gluconeogenesis. Similarly there was no effect of the steroid on either the activity ratio or the total pyruvate kinase activity in the cells. It is suggested that the acute effect of the dexamethasone to increase gluconeogenesis resides at the level of phosphoenolpyruvate formation, i.e. pyruvate carboxylase and possibly phosphoenolpyruvate carboxykinase.

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24

Schadewaldt, P., E. Lammers e W. Staib. "Influence of insulin and glucose on pyruvate catabolism in perfused rat hindlimbs". Biochemical Journal 227, n. 1 (1 aprile 1985): 177–82. http://dx.doi.org/10.1042/bj2270177.

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The effects of insulin and glucose on the oxidative decarboxylation of pyruvate in isolated rat hindlimbs was studied in non-recirculating perfusion with [1-14C]pyruvate. Insulin increased the calculated pyruvate decarboxylation rate in a concentration-dependent manner. At supramaximal insulin concentrations, the calculated pyruvate decarboxylation rate was increased by about 40% in perfusions with 0.15-1.5 mM-pyruvate. Glucose up to 20 mM had no effect. In the presence of insulin and low physiological pyruvate concentrations (0.15 mM), glucose increased the calculated pyruvate oxidation. This effect was abolished by high concentrations of pyruvate (1 mM). The data provide evidence that in resting perfused rat skeletal muscle insulin primarily increased the activity of the pyruvate dehydrogenase complex. The effect of glucose was due to increased intracellular pyruvate supply.

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Johnson, Matthew L., Rajaa Hussien, Michael A. Horning e George A. Brooks. "Transpulmonary pyruvate kinetics". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 301, n. 3 (settembre 2011): R769—R774. http://dx.doi.org/10.1152/ajpregu.00206.2011.

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Shuttling of intermediary metabolites, such as pyruvate, contributes to the dynamic energy and biosynthetic needs of tissues. Tracer kinetic studies offer a powerful tool to measure the metabolism of substrates like pyruvate that are simultaneously taken up from and released into the circulation by organs. However, we understood that during each circulatory passage, the entire cardiac output transits the pulmonary circulation. Therefore, we examined the transpulmonary pyruvate kinetics in an anesthetized rat model during an unstimulated (Con), lactate clamp (LC), and epinephrine infusion (Epi) conditions using a primed-continuous infusion of [U-13C]pyruvate. Compared with Con and Epi stimulation, LC significantly increased mixed central venous ([v̄]) and arterial ([a]) pyruvate concentrations ( P < 0.05). We hypothesized that the lungs, specifically the pulmonary capillary beds are sites of simultaneous production and removal of pyruvate and contributes significantly to whole body carbohydrate intermediary metabolism. Transpulmonary net pyruvate balances were positive during all three conditions, indicating net pyruvate uptake. Net balance was significantly greater during epinephrine stimulation compared with the unstimulated control ( P < 0.05). Tracer-measured pyruvate fractional extraction averaged 42.8 ± 5.8% for all three conditions and was significantly higher during epinephrine stimulation ( P < 0.05) than during either Con or LC conditions, that did not differ from each other. Pyruvate total release (tracer measured uptake − net balance) was significantly higher during epinephrine stimulation (400 ± 100 μg/min) vs. Con (30 ± 20 μg/min) ( P < 0.05). These data are interpreted to mean that significant pyruvate extraction occurs during circulatory transport across lung parenchyma. The extent of pulmonary parenchymal pyruvate extraction predicts high expression of monocarboxylate (lactate/pyruvate) transporters (MCTs) in the tissue. Western blot analysis of whole lung homogenates detected three isoforms, MCT1, MCT2, and MCT4. We conclude that a major site of circulating pyruvate extraction resides with the lungs and that during times of elevated circulating lactate, pyruvate, or epinephrine stimulation, pyruvate extraction is increased.

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Wagner, Nicole, Quang Hon Tran, Hanno Richter, Paul M. Selzer e Gottfried Unden. "Pyruvate Fermentation by Oenococcus oeni and Leuconostoc mesenteroides and Role of Pyruvate Dehydrogenase in Anaerobic Fermentation". Applied and Environmental Microbiology 71, n. 9 (settembre 2005): 4966–71. http://dx.doi.org/10.1128/aem.71.9.4966-4971.2005.

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ABSTRACT The heterofermentative lactic acid bacteria Oenococcus oeni and Leuconostoc mesenteroides are able to grow by fermentation of pyruvate as the carbon source (2 pyruvate → 1 lactate + 1 acetate + 1 CO2). The growth yields amount to 4.0 and 5.3 g (dry weight)/mol of pyruvate, respectively, suggesting formation of 0.5 mol ATP/mol pyruvate. Pyruvate is oxidatively decarboxylated by pyruvate dehydrogenase to acetyl coenzyme A, which is then converted to acetate, yielding 1 mol of ATP. For NADH reoxidation, one further pyruvate molecule is reduced to lactate. The enzymes of the pathway were present after growth on pyruvate, and genome analysis showed the presence of the corresponding structural genes. The bacteria contain, in addition, pyruvate oxidase activity which is induced under microoxic conditions. Other homo- or heterofermentative lactic acid bacteria showed only low pyruvate fermentation activity.

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Burnell, JN, CLD Jenkins e MD Hatch. "Regulation of C4 Photosynthesis A Role for Pyruvate in Regulating Pyruvate,Pi Dikinase Activity in vivo". Functional Plant Biology 13, n. 2 (1986): 203. http://dx.doi.org/10.1071/pp9860203.

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Results are presented in support of the view that pyruvate levels are critical in the light-dark regulation of pyruvate,PI dikinase in vivo. In an in vitro system containing purified Zea mays pyruvate,PI dikinase, increasing pyruvate reduced both the initial rate and the final extent of ADP-mediated inactivation of the enzyme. Pyruvate also reversed the inhibitory effect of ADP on the initial rate of PI-mediated activation of pyruvate,P*i dikinase. With intact Zea mays leaves, inactivation of pyruvate,PI dikinase in darkened leaves was prevented by anaerobic conditions or reduced temperature; both treatments resulted in elevated steady-state levels of pyruvate. Added pyruvate was shown to substantially increase the level of active pyruvate,PI dikinase in chloroplasts incubated with PI in the dark but not in the light. The likely physiological significance of these results is discussed.

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Moreno, Karlos X., Scott M. Sabelhaus, Matthew E. Merritt, A. Dean Sherry e Craig R. Malloy. "Competition of pyruvate with physiological substrates for oxidation by the heart: implications for studies with hyperpolarized [1-13C]pyruvate". American Journal of Physiology-Heart and Circulatory Physiology 298, n. 5 (maggio 2010): H1556—H1564. http://dx.doi.org/10.1152/ajpheart.00656.2009.

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Carbon 13 nuclear magnetic resonance (NMR) isotopomer analysis was used to measure the rates of oxidation of long-chain fatty acids, ketones, and pyruvate to determine the minimum pyruvate concentration ([pyruvate]) needed to suppress oxidation of these alternative substrates. Substrate mixtures were chosen to represent either the fed or fasted state. At physiological [pyruvate], fatty acids and ketones supplied the overwhelming majority of acetyl-CoA. Under conditions mimicking the fed state, 3 mM pyruvate provided ∼80% of acetyl-CoA, but under fasting conditions 6 mM pyruvate contributed only 33% of acetyl-CoA. Higher [pyruvate], 10–25 mM, was associated with transient reduced cardiac output, but overall hemodynamic performance was unchanged after equilibration. These observations suggested that 3–6 mM pyruvate in the coronary arteries would be an appropriate target for studies with hyperpolarized [1-13C]pyruvate. However, the metabolic products of 3 mM hyperpolarized [1-13C]pyruvate could not be detected in the isolated heart during perfusion with a physiological mixture of substrates including 3% albumin. In the presence of albumin even at high concentrations of pyruvate, 20 mM, hyperpolarized H13CO3− could be detected only in the absence of competing substrates. Highly purified albumin (but not albumin from plasma) substantially reduced the longitudinal relaxation time of [1-13C]pyruvate. In conclusion, studies of cardiac metabolism using hyperpolarized [1-13C]pyruvate are sensitive to the effects of competing substrates on pyruvate oxidation.

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Panchal, Ashish R., Blandine Comte, Hazel Huang, Todd Kerwin, Ahmed Darvish, Christine Des Rosiers, Henri Brunengraber e William C. Stanley. "Partitioning of pyruvate between oxidation and anaplerosis in swine hearts". American Journal of Physiology-Heart and Circulatory Physiology 279, n. 5 (1 novembre 2000): H2390—H2398. http://dx.doi.org/10.1152/ajpheart.2000.279.5.h2390.

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The goal of this study was to measure flux through pyruvate carboxylation and decarboxylation in the heart in vivo. These rates were measured in the anterior wall of normal anesthetized swine hearts by infusing [U-13C3]lactate and/or [U-13C3] pyruvate into the left anterior descending (LAD) coronary artery. After 1 h, the tissue was freeze-clamped and analyzed by gas chromatography-mass spectrometry for the mass isotopomer distribution of citrate and its oxaloacetate moiety. LAD blood pyruvate and lactate enrichments and concentrations were constant after 15 min of infusion. Under near-normal physiological concentrations of lactate and pyruvate, pyruvate carboxylation and decarboxylation accounted for 4.7 ± 0.3 and 41.5 ± 2.0% of citrate formation, respectively. Similar relative fluxes were found when arterial pyruvate was raised from 0.2 to 1.1 mM. Addition of 1 mM octanoate to 1 mM pyruvate inhibited pyruvate decarboxylation by 93% without affecting carboxylation. The absence of M1 and M2 pyruvate demonstrated net irreversible pyruvate carboxylation. Under our experimental conditions we found that pyruvate carboxylation in the in vivo heart accounts for at least 3–6% of the citric acid cycle flux despite considerable variation in the flux through pyruvate decarboxylation.

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Curi, R., P. Newsholme e E. A. Newsholme. "Metabolism of pyruvate by isolated rat mesenteric lymphocytes, lymphocyte mitochondria and isolated mouse macrophages". Biochemical Journal 250, n. 2 (1 marzo 1988): 383–88. http://dx.doi.org/10.1042/bj2500383.

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1. The activities of pyruvate dehydrogenase in rat lymphocytes and mouse macrophages are much lower than those of the key enzymes of glycolysis and glutaminolysis. However, the rates of utilization of pyruvate (at 2 mM), from the incubation medium, are not markedly lower than the rate of utilization of glucose by incubated lymphocytes or that of glutamine by incubated macrophages. This suggests that the low rate of oxidation of pyruvate produced from either glucose or glutamine in these cells is due to the high capacity of lactate dehydrogenase, which competes with pyruvate dehydrogenase for pyruvate. 2. Incubation of either macrophages or lymphocytes with dichloroacetate had no effect on the activity of subsequently isolated pyruvate dehydrogenase; incubation of mitochondria isolated from lymphocytes with dichloroacetate had no effect on the rate of conversion of [1-14C]pyruvate into 14CO2, and the double-reciprocal plot of [1-14C]pyruvate concentration against rate of 14CO2 production was linear. In contrast, ADP or an uncoupling agent increased the rate of 14CO2 production from [1-14C]pyruvate by isolated lymphocyte mitochondria. These data suggest either that pyruvate dehydrogenase is primarily in the a form or that pyruvate dehydrogenase in these cells is not controlled by an interconversion cycle, but by end-product inhibition by NADH and/or acetyl-CoA. 3. The rate of conversion of [3-14C]pyruvate into CO2 was about 15% of that from [1-14C]pyruvate in isolated lymphocytes, but was only 1% in isolated lymphocyte mitochondria. The inhibitor of mitochondrial pyruvate transport, alpha-cyano-4-hydroxycinnamate, inhibited both [1-14C]- and [3-14C]-pyruvate conversion into 14CO2 to the same extent, and by more than 80%. 4. Incubations of rat lymphocytes with concanavalin A had no effect on the rate of conversion of [1-14C]pyruvate into 14CO2, but increased the rate of conversion of [3-14C]pyruvate into 14CO2 by about 50%. This suggests that this mitogen causes a stimulation of the activity of pyruvate carboxylase.

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31

Zanella, A., P. Bianchi e E. Fermo. "Pyruvate kinase deficiency". Haematologica 92, n. 6 (1 giugno 2007): 721–23. http://dx.doi.org/10.3324/haematol.11469.

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32

Oria-Hernández, Jesús, Nallely Cabrera, Ruy Pérez-Montfort e Leticia Ramírez-Silva. "Pyruvate Kinase Revisited". Journal of Biological Chemistry 280, n. 45 (7 settembre 2005): 37924–29. http://dx.doi.org/10.1074/jbc.m508490200.

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33

Brown, G. K., L. J. Otero, M. LeGris e R. M. Brown. "Pyruvate dehydrogenase deficiency." Journal of Medical Genetics 31, n. 11 (1 novembre 1994): 875–79. http://dx.doi.org/10.1136/jmg.31.11.875.

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34

Miwa, S., e H. Fujii. "Pyruvate kinase deficiency". Clinical Biochemistry 23, n. 2 (aprile 1990): 155–57. http://dx.doi.org/10.1016/0009-9120(90)80029-i.

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35

VAN COSTER, R. N., P. M. FERNHOFF e D. C. DE VIVO. "Pyruvate Carboxylase Deficiency". Pediatric Research 30, n. 1 (luglio 1991): 1???4. http://dx.doi.org/10.1203/00006450-199107010-00001.

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36

Ambasht, P. K., e Arvind M. Kayastha. "Plant Pyruvate Kinase". Biologia plantarum 45, n. 1 (1 marzo 2002): 1–10. http://dx.doi.org/10.1023/a:1015173724712.

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37

O'Donnell-Tormey, J., C. F. Nathan, K. Lanks, C. J. DeBoer e J. de la Harpe. "Secretion of pyruvate. An antioxidant defense of mammalian cells." Journal of Experimental Medicine 165, n. 2 (1 febbraio 1987): 500–514. http://dx.doi.org/10.1084/jem.165.2.500.

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Cells in culture are exposed to marked oxidative stress, H2O2 being one of the predominant agents. Pyruvate and other alpha-ketoacids reacted rapidly, stoichiometrically, and nonenzymatically with H2O2, and they protected cells from its cytolytic effects. All five human and murine cell types studied, both malignant and nonmalignant, released pyruvate at an initial rate of 35-60 microM/h/2.5 X 10(6) cells when placed in 1 ml pyruvate-free medium. After 6-12 h a plateau of 60-150 microM pyruvate was attained, corresponding to concentrations reported for normal human serum and plasma. The rate of pyruvate accumulation was almost doubled in the presence of exogenous catalase, suggesting that released pyruvate functions as an antioxidant. The rate of pyruvate accumulation was dependent on cell number. Succinate, fumarate, citrate, oxaloacetate, alpha-ketoglutarate, and malate were not secreted in significant amounts from P815 cells; export was specific for pyruvate and lactate among the metabolites tested. Extracellular pyruvate was in equilibrium with intracellular stores. Thus, cells conditioned the extracellular medium with pyruvate at the expense of intracellular pyruvate, until homeostatic levels were attained in both compartments. We propose that cells plated at low density in the absence of exogenous pyruvate fail to thrive for two reasons: prolonged depletion of intracellular pyruvate and prolonged vulnerability to oxidant stress.

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38

Bender, Tom, Gabrielle Pena e Jean‐Claude Martinou. "Regulation of mitochondrial pyruvate uptake by alternative pyruvate carrier complexes". EMBO Journal 34, n. 7 (11 febbraio 2015): 911–24. http://dx.doi.org/10.15252/embj.201490197.

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39

Knyzhnykova, D. V., Ya V. Topolnikova, I. S. Kucherenko e O. O. Soldatkin. "Development of pyruvate oxidase-based amperometric biosensor for pyruvate determination". Biopolymers and Cell 34, n. 1 (28 febbraio 2018): 14–23. http://dx.doi.org/10.7124/bc.00096c.

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40

Zangari, Joséphine, Francesco Petrelli, Benoît Maillot e Jean-Claude Martinou. "The Multifaceted Pyruvate Metabolism: Role of the Mitochondrial Pyruvate Carrier". Biomolecules 10, n. 7 (17 luglio 2020): 1068. http://dx.doi.org/10.3390/biom10071068.

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Abstract (sommario):

Pyruvate, the end product of glycolysis, plays a major role in cell metabolism. Produced in the cytosol, it is oxidized in the mitochondria where it fuels the citric acid cycle and boosts oxidative phosphorylation. Its sole entry point into mitochondria is through the recently identified mitochondrial pyruvate carrier (MPC). In this review, we report the latest findings on the physiology of the MPC and we discuss how a dysfunctional MPC can lead to diverse pathologies, including neurodegenerative diseases, metabolic disorders, and cancer.

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41

Rosche, Bettina, Michael Breuer, Bernhard Hauer e Peter L. Rogers. "Role of pyruvate in enhancing pyruvate decarboxylase stability towards benzaldehyde". Journal of Biotechnology 115, n. 1 (gennaio 2005): 91–99. http://dx.doi.org/10.1016/j.jbiotec.2004.08.002.

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42

Lindqvist, Ylva, e Gunter Schneider. "Thiamin diphosphate dependent enzymes: transketolase, pyruvate oxidase and pyruvate decarboxylase". Current Opinion in Structural Biology 3, n. 6 (gennaio 1993): 896–901. http://dx.doi.org/10.1016/0959-440x(93)90153-c.

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43

Carter, Tonia C., e Haldane G. Coore. "Effects of pyruvate on pyruvate dehydrogenase kinase of rat heart". Molecular and Cellular Biochemistry 149-150, n. 1 (agosto 1995): 71–75. http://dx.doi.org/10.1007/bf01076565.

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44

Lyn, Deborah, e Haldane G. Coore. "Pyruvate inhibition of pyruvate dehydrogenase kinase is a physiological variable". Biochemical and Biophysical Research Communications 126, n. 3 (febbraio 1985): 992–98. http://dx.doi.org/10.1016/0006-291x(85)90283-9.

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45

Soo, Po-Chi, Yu-Tze Horng, Meng-Jiun Lai, Jun-Rong Wei, Shang-Chen Hsieh, Yung-Lin Chang, Yu-Huan Tsai e Hsin-Chih Lai. "Pirin Regulates Pyruvate Catabolism by Interacting with the Pyruvate Dehydrogenase E1 Subunit and Modulating Pyruvate Dehydrogenase Activity". Journal of Bacteriology 189, n. 1 (15 settembre 2006): 109–18. http://dx.doi.org/10.1128/jb.00710-06.

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ABSTRACT The protein pirin, which is involved in a variety of biological processes, is conserved from prokaryotic microorganisms, fungi, and plants to mammals. It acts as a transcriptional cofactor or an apoptosis-related protein in mammals and is involved in seed germination and seedling development in plants. In prokaryotes, while pirin is stress induced in cyanobacteria and may act as a quercetinase in Escherichia coli, the functions of pirin orthologs remain mostly uncharacterized. We show that the Serratia marcescens pirin (pirin Sm ) gene encodes an ortholog of pirin protein. Protein pull-down and bacterial two-hybrid assays followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electrospray ionization-tandem mass spectrometry analyses showed the pyruvate dehydrogenase (PDH) E1 subunit as a component interacting with the pirin Sm gene. Functional analyses showed that both PDH E1 subunit activity and PDH enzyme complex activity are inhibited by the pirin Sm gene in S. marcescens CH-1. The S. marcescens CH-1 pirin Sm gene was subsequently mutated by insertion-deletion homologous recombination. Accordingly, the PDH E1 and PDH enzyme complex activities and cellular ATP concentration increased up to 250%, 140%, and 220%, respectively, in the S. marcescens CH-1 pirin Sm mutant. Concomitantly, the cellular NADH/NAD+ ratio increased in the pirin Sm mutant, indicating increased tricarboxylic acid (TCA) cycle activity. Our results show that the pirin Sm gene plays a regulatory role in the process of pyruvate catabolism to acetyl coenzyme A through interaction with the PDH E1 subunit and inhibiting PDH enzyme complex activity in S. marcescens CH-1, and they suggest that pirin Sm is an important protein involved in determining the direction of pyruvate metabolism towards either the TCA cycle or the fermentation pathways.

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46

Burgess, Shawn C., Katsumi Iizuka, Nam Ho Jeoung, Robert A. Harris, Yoshihiro Kashiwaya, Richard L. Veech, Tatsuya Kitazume e Kosaku Uyeda. "Carbohydrate-response Element-binding Protein Deletion Alters Substrate Utilization Producing an Energy-deficient Liver". Journal of Biological Chemistry 283, n. 3 (27 novembre 2007): 1670–78. http://dx.doi.org/10.1074/jbc.m706540200.

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Livers from mice lacking the carbohydrate-responsive element-binding protein (ChREBP) were compared with wild type (WT) mice to determine the effect of this transcription factor on hepatic energy metabolism. The pyruvate dehydrogenase complex was considerably more active in ChREBP-/- mice because of diminished pyruvate dehydrogenase kinase activity. Greater pyruvate dehydrogenase complex activity caused a stimulation of lactate and pyruvate oxidation, and it significantly impaired fatty acid oxidation in perfused livers from ChREBP-/- mice. This shift in mitochondrial substrate utilization led to a 3-fold reduction of the free cytosolic [NAD+]/[NADH] ratio, a 1.7-fold increase in the free mitochondrial [NAD+]/[NADH] ratio, and a 2-fold decrease in the free cytosolic [ATP]/[ADP][Pi] ratio in the ChREBP-/- liver compared with control. Hepatic pyruvate carboxylase flux was impaired with ChREBP deletion secondary to decreased fatty acid oxidation, increased pyruvate oxidation, and limited pyruvate availability because of reduced activity of liver pyruvate kinase and malic enzyme, which replenish pyruvate via glycolysis and pyruvate cycling. Overall, the shift from fat utilization to pyruvate and lactate utilization resulted in a decrease in the energy of ATP hydrolysis and a hypo-energetic state in the livers of ChREBP-/- mice.

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47

Ledee, Dolena R., Masaki Kajimoto, Colleen M. O'Kelly Priddy, Aaron K. Olson, Nancy Isern, Isabelle Robillard-Frayne, Christine Des Rosiers e Michael A. Portman. "Pyruvate modifies metabolic flux and nutrient sensing during extracorporeal membrane oxygenation in an immature swine model". American Journal of Physiology-Heart and Circulatory Physiology 309, n. 1 (1 luglio 2015): H137—H146. http://dx.doi.org/10.1152/ajpheart.00011.2015.

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Extracorporeal membrane oxygenation (ECMO) provides mechanical circulatory support for infants and children with postoperative cardiopulmonary failure. Nutritional support is mandatory during ECMO although specific actions for substrates on the heart have not been delineated. Prior work shows that enhancing pyruvate oxidation promotes successful weaning from ECMO. Accordingly, we tested the hypothesis that prolonged systemic pyruvate supplementation activates pyruvate oxidation in an immature swine model in vivo. Twelve male mixed-breed Yorkshire piglets (age 30–49 days) received systemic infusion of either normal saline (group C) or pyruvate (group P) during the final 6 h of 8 h of ECMO. Over the final hour, piglets received [2-13C] pyruvate, as a reference substrate for oxidation, and [13C6]-l-leucine, as an indicator for amino acid oxidation and protein synthesis. A significant increase in lactate and pyruvate concentrations occurred, along with an increase in the absolute concentration of the citric acid cycle intermediates. An increase in anaplerotic flux through pyruvate carboxylation in group P occurred compared with no change in pyruvate oxidation. Additionally, pyruvate promoted an increase in the phosphorylation state of several nutrient-sensitive enzymes, like AMP-activated protein kinase and acetyl CoA carboxylase, suggesting activation for fatty acid oxidation. Pyruvate also promoted O-GlcNAcylation through the hexosamine biosynthetic pathway. In conclusion, although prolonged pyruvate supplementation did not alter pyruvate oxidation, it did elicit changes in nutrient- and energy-sensitive pathways. Therefore, the observed results support the further study of pyruvate and its downstream effect on cardiac function.

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48

Fang-Qiang, Zhou. "Pyruvate Research and Clinical Application Outlooks A Revolutionary Medical Advance". International Journal of Nutrition 5, n. 1 (14 gennaio 2020): 1–9. http://dx.doi.org/10.14302/issn.2379-7835.ijn-20-3159.

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Abstract (sommario):

Pyruvate holds superior biomedical properties in increase of hypoxia tolerance, correction of severe acidosis, exertion of anti-oxidative stress and protection of mitochondria against apoptosis, so that it improves multi-organ function in various pathogenic insults. Particularly, pyruvate preserves key enzyme: pyruvate dehydrogenase (PDH) activity through direct inhibition of pyruvate dehydrogenase kinas (PDK), as a PDH activator, in hypoxia. Therefore, pyruvate is robustly beneficial for cell/organ function over citrate, acetate, lactate, bicarbonate and chloride as anions in current medical fluids. Pyruvate-enriched oral rehydration salt/solution (Pyr-ORS) and pyruvate-based intravenous (IV) fluids would be more beneficial than WHO-ORS and current IV fluids in both crystalloids and colloids, respectively. Pyruvate-containing fluids as the new generation would be not only a volume expander, but also a therapeutic agent simultaneously in fluid resuscitation in critical care patients. Pyruvate may be also beneficial in prevent and treatment of diabetes, aging and even cancer. Pyruvate clinical applications indicates a new revolutionary medical advance, following the WHO-ORS prevalence, this century.

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49

Jones, C. G., e M. A. Titheradge. "The effect of treatment of the rat with bacterial endotoxin on gluconeogenesis and pyruvate metabolism in subsequently isolated hepatocytes". Biochemical Journal 289, n. 1 (1 gennaio 1993): 169–72. http://dx.doi.org/10.1042/bj2890169.

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Abstract (sommario):

The effect of treatment of rats with bacterial endotoxin on gluconeogenesis and the flux through pyruvate kinase, phosphoenolpyruvate carboxykinase (PEPCK), pyruvate carboxylase and pyruvate dehydrogenase (PDH) was measured in isolated hepatocytes, prepared from animals starved for 18 h, incubated in the presence of 1 mM pyruvate. The lipopolysaccharide reduced gluconeogenesis by 50% and lowered the flux through pyruvate kinase, PEPCK and pyruvate carboxylase by comparable amounts. There was no effect of endotoxaemia on PDH flux, indicating that the lowered rate of gluconeogenesis is not the result of a redistribution of pyruvate metabolism between oxidation and carboxylation. The results confirm that a stimulation of pyruvate kinase activity following treatment with lipopolysaccharide is not involved in the inhibition of gluconeogenesis, but that the effect resides at the level of phosphoenolpyruvate formation. The most favoured mechanism for the inhibition of glucose synthesis is via an inhibition of PEPCK and subsequent feedback inhibition of pyruvate carboxylase, although a secondary effect at the level of the mitochondria and pyruvate carboxylase cannot be excluded.

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50

Wu, Jianting, Yannan Li, Zhiming Cai e Ye Jin. "Pyruvate-Associated Acid Resistance in Bacteria". Applied and Environmental Microbiology 80, n. 14 (2 maggio 2014): 4108–13. http://dx.doi.org/10.1128/aem.01001-14.

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ABSTRACTGlucose confers acid resistance on exponentially growing bacteria by repressing formation of the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex and consequently activating acid resistance genes. Therefore, in a glucose-rich growth environment, bacteria are capable of resisting acidic stresses due to low levels of cAMP-CRP. Here we reveal a second mechanism for glucose-conferred acid resistance. We show that glucose induces acid resistance in exponentially growing bacteria through pyruvate, the glycolysis product. Pyruvate and/or the downstream metabolites induce expression of the small noncoding RNA (sncRNA) Spot42, and the sncRNA, in turn, activates expression of the master regulator of acid resistance, RpoS. In contrast to glucose, pyruvate has little effect on levels of the cAMP-CRP complex and does not require the complex for its effects on acid resistance. Another important difference between glucose and pyruvate is that pyruvate can be produced by bacteria. This means that bacteria have the potential to protect themselves from acidic stresses by controlling glucose-derived generation of pyruvate, pyruvate-acetate efflux, or reversion from acetate to pyruvate. We tested this possibility by shutting down pyruvate-acetate efflux and found that the resulting accumulation of pyruvate elevated acid resistance. Many sugars can be broken into glucose, and the subsequent glycolysis generates pyruvate. Therefore, pyruvate-associated acid resistance is not confined to glucose-grown bacteria but is functional in bacteria grown on various sugars.

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