Sample records for lactate dehydrogenase level

  1. 21 CFR 862.1440 - Lactate dehydrogenase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Systems § 862.1440 Lactate dehydrogenase test system. (a) Identification. A lactate dehydrogenase test system is a device intended to measure the activity of the enzyme lactate dehydrogenase in serum. Lactate... hepatitis, cirrhosis, and metastatic carcinoma of the liver, cardiac diseases such as myocardial infarction...

  2. Biochemical and structural characterization of Cryptosporidium parvum Lactate dehydrogenase.

    PubMed

    Cook, William J; Senkovich, Olga; Hernandez, Agustin; Speed, Haley; Chattopadhyay, Debasish

    2015-03-01

    The protozoan parasite Cryptosporidium parvum causes waterborne diseases worldwide. There is no effective therapy for C. parvum infection. The parasite depends mainly on glycolysis for energy production. Lactate dehydrogenase is a major regulator of glycolysis. This paper describes the biochemical characterization of C. parvum lactate dehydrogenase and high resolution crystal structures of the apo-enzyme and four ternary complexes. The ternary complexes capture the enzyme bound to NAD/NADH or its 3-acetylpyridine analog in the cofactor binding pocket, while the substrate binding site is occupied by one of the following ligands: lactate, pyruvate or oxamate. The results reveal distinctive features of the parasitic enzyme. For example, C. parvum lactate dehydrogenase prefers the acetylpyridine analog of NADH as a cofactor. Moreover, it is slightly less sensitive to gossypol inhibition compared with mammalian lactate dehydrogenases and not inhibited by excess pyruvate. The active site loop and the antigenic loop in C. parvum lactate dehydrogenase are considerably different from those in the human counterpart. Structural features and enzymatic properties of C. parvum lactate dehydrogenase are similar to enzymes from related parasites. Structural comparison with malate dehydrogenase supports a common ancestry for the two genes. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Evolution of D-lactate dehydrogenase activity from glycerol dehydrogenase and its utility for D-lactate production from lignocellulose.

    PubMed

    Wang, Qingzhao; Ingram, Lonnie O; Shanmugam, K T

    2011-11-22

    Lactic acid, an attractive, renewable chemical for production of biobased plastics (polylactic acid, PLA), is currently commercially produced from food-based sources of sugar. Pure optical isomers of lactate needed for PLA are typically produced by microbial fermentation of sugars at temperatures below 40 °C. Bacillus coagulans produces L(+)-lactate as a primary fermentation product and grows optimally at 50 °C and pH 5, conditions that are optimal for activity of commercial fungal cellulases. This strain was engineered to produce D(-)-lactate by deleting the native ldh (L-lactate dehydrogenase) and alsS (acetolactate synthase) genes to impede anaerobic growth, followed by growth-based selection to isolate suppressor mutants that restored growth. One of these, strain QZ19, produced about 90 g L(-1) of optically pure D(-)-lactic acid from glucose in < 48 h. The new source of D-lactate dehydrogenase (D-LDH) activity was identified as a mutated form of glycerol dehydrogenase (GlyDH; D121N and F245S) that was produced at high levels as a result of a third mutation (insertion sequence). Although the native GlyDH had no detectable activity with pyruvate, the mutated GlyDH had a D-LDH specific activity of 0.8 μmoles min(-1) (mg protein)(-1). By using QZ19 for simultaneous saccharification and fermentation of cellulose to D-lactate (50 °C and pH 5.0), the cellulase usage could be reduced to 1/3 that required for equivalent fermentations by mesophilic lactic acid bacteria. Together, the native B. coagulans and the QZ19 derivative can be used to produce either L(+) or D(-) optical isomers of lactic acid (respectively) at high titers and yields from nonfood carbohydrates.

  4. Evolution of D-lactate dehydrogenase activity from glycerol dehydrogenase and its utility for D-lactate production from lignocellulose

    PubMed Central

    Wang, Qingzhao; Ingram, Lonnie O.; Shanmugam, K. T.

    2011-01-01

    Lactic acid, an attractive, renewable chemical for production of biobased plastics (polylactic acid, PLA), is currently commercially produced from food-based sources of sugar. Pure optical isomers of lactate needed for PLA are typically produced by microbial fermentation of sugars at temperatures below 40 °C. Bacillus coagulans produces L(+)-lactate as a primary fermentation product and grows optimally at 50 °C and pH 5, conditions that are optimal for activity of commercial fungal cellulases. This strain was engineered to produce D(−)-lactate by deleting the native ldh (L-lactate dehydrogenase) and alsS (acetolactate synthase) genes to impede anaerobic growth, followed by growth-based selection to isolate suppressor mutants that restored growth. One of these, strain QZ19, produced about 90 g L-1 of optically pure D(−)-lactic acid from glucose in < 48 h. The new source of D-lactate dehydrogenase (D-LDH) activity was identified as a mutated form of glycerol dehydrogenase (GlyDH; D121N and F245S) that was produced at high levels as a result of a third mutation (insertion sequence). Although the native GlyDH had no detectable activity with pyruvate, the mutated GlyDH had a D-LDH specific activity of 0.8 μmoles min-1 (mg protein)-1. By using QZ19 for simultaneous saccharification and fermentation of cellulose to D-lactate (50 °C and pH 5.0), the cellulase usage could be reduced to 1/3 that required for equivalent fermentations by mesophilic lactic acid bacteria. Together, the native B. coagulans and the QZ19 derivative can be used to produce either L(+) or D(−) optical isomers of lactic acid (respectively) at high titers and yields from nonfood carbohydrates. PMID:22065761

  5. Genetics Home Reference: lactate dehydrogenase deficiency

    MedlinePlus

    ... dehydrogenase-B pieces (subunits) of the lactate dehydrogenase enzyme. This enzyme is found throughout the body and is important ... cells. There are five different forms of this enzyme, each made up of four protein subunits. Various ...

  6. 21 CFR 862.1445 - Lactate dehydrogenase isoenzymes test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... dehydrogenase isoenzymes test system is a device intended to measure the activity of lactate dehydrogenase isoenzymes (a group of enzymes with similar biological activity) in serum. Measurements of lactate...

  7. 21 CFR 862.1445 - Lactate dehydrogenase isoenzymes test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... dehydrogenase isoenzymes test system is a device intended to measure the activity of lactate dehydrogenase isoenzymes (a group of enzymes with similar biological activity) in serum. Measurements of lactate...

  8. High brain lactate is a hallmark of aging and caused by a shift in the lactate dehydrogenase A/B ratio

    PubMed Central

    Ross, Jaime M.; Öberg, Johanna; Brené, Stefan; Coppotelli, Giuseppe; Terzioglu, Mügen; Pernold, Karin; Goiny, Michel; Sitnikov, Rouslan; Kehr, Jan; Trifunovic, Aleksandra; Larsson, Nils-Göran; Hoffer, Barry J.; Olson, Lars

    2010-01-01

    At present, there are few means to track symptomatic stages of CNS aging. Thus, although metabolic changes are implicated in mtDNA mutation-driven aging, the manifestations remain unclear. Here, we used normally aging and prematurely aging mtDNA mutator mice to establish a molecular link between mitochondrial dysfunction and abnormal metabolism in the aging process. Using proton magnetic resonance spectroscopy and HPLC, we found that brain lactate levels were increased twofold in both normally and prematurely aging mice during aging. To correlate the striking increase in lactate with tissue pathology, we investigated the respiratory chain enzymes and detected mitochondrial failure in key brain areas from both normally and prematurely aging mice. We used in situ hybridization to show that increased brain lactate levels were caused by a shift in transcriptional activities of the lactate dehydrogenases to promote pyruvate to lactate conversion. Separation of the five tetrameric lactate dehydrogenase (LDH) isoenzymes revealed an increase of those dominated by the Ldh-A product and a decrease of those rich in the Ldh-B product, which, in turn, increases pyruvate to lactate conversion. Spectrophotometric assays measuring LDH activity from the pyruvate and lactate sides of the reaction showed a higher pyruvate → lactate activity in the brain. We argue for the use of lactate proton magnetic resonance spectroscopy as a noninvasive strategy for monitoring this hallmark of the aging process. The mtDNA mutator mouse allows us to conclude that the increased LDH-A/LDH-B ratio causes high brain lactate levels, which, in turn, are predictive of aging phenotypes. PMID:21041631

  9. High brain lactate is a hallmark of aging and caused by a shift in the lactate dehydrogenase A/B ratio.

    PubMed

    Ross, Jaime M; Öberg, Johanna; Brené, Stefan; Coppotelli, Giuseppe; Terzioglu, Mügen; Pernold, Karin; Goiny, Michel; Sitnikov, Rouslan; Kehr, Jan; Trifunovic, Aleksandra; Larsson, Nils-Göran; Hoffer, Barry J; Olson, Lars

    2010-11-16

    At present, there are few means to track symptomatic stages of CNS aging. Thus, although metabolic changes are implicated in mtDNA mutation-driven aging, the manifestations remain unclear. Here, we used normally aging and prematurely aging mtDNA mutator mice to establish a molecular link between mitochondrial dysfunction and abnormal metabolism in the aging process. Using proton magnetic resonance spectroscopy and HPLC, we found that brain lactate levels were increased twofold in both normally and prematurely aging mice during aging. To correlate the striking increase in lactate with tissue pathology, we investigated the respiratory chain enzymes and detected mitochondrial failure in key brain areas from both normally and prematurely aging mice. We used in situ hybridization to show that increased brain lactate levels were caused by a shift in transcriptional activities of the lactate dehydrogenases to promote pyruvate to lactate conversion. Separation of the five tetrameric lactate dehydrogenase (LDH) isoenzymes revealed an increase of those dominated by the Ldh-A product and a decrease of those rich in the Ldh-B product, which, in turn, increases pyruvate to lactate conversion. Spectrophotometric assays measuring LDH activity from the pyruvate and lactate sides of the reaction showed a higher pyruvate → lactate activity in the brain. We argue for the use of lactate proton magnetic resonance spectroscopy as a noninvasive strategy for monitoring this hallmark of the aging process. The mtDNA mutator mouse allows us to conclude that the increased LDH-A/LDH-B ratio causes high brain lactate levels, which, in turn, are predictive of aging phenotypes.

  10. Lactate dehydrogenase activity drives hair follicle stem cell activation

    PubMed Central

    Aimee, Flores; John, Schell; Abby, Krall; David, Jelinek; Matilde, Miranda; Melina, Grigorian; Daniel, Braas; White Andrew, C; Jessica, Zhou; Nick, Graham; Thomas, Graeber; Pankaj, Seth; Denis, Evseenko; Hilary, Coller; Jared, Rutter; Heather, Christofk; Lowry William, E

    2017-01-01

    Summary While normally dormant, Hair Follicle Stem Cells (HFSCs) quickly become activated to divide during a new hair cycle. The quiescence of HFSCs is known to be regulated by a number of intrinsic and extrinsic mechanisms. Here we provide several lines of evidence to demonstrate that HFSCs utilize glycolytic metabolism and produce significantly more lactate than other cells in the epidermis. Furthermore, lactate generation appears to be critical for the activation of HFSCs as deletion of lactate dehydrogenase (Ldha) prevented their activation. Conversely, genetically promoting lactate production in HFSCs through mitochondrial pyruvate carrier (Mpc1) deletion accelerated their activation and the hair cycle. Finally, we identify small molecules that increase lactate production by stimulating Myc levels or inhibiting Mpc1 carrier activity and can topically induce the hair cycle. These data suggest that HFSCs maintain a metabolic state that allow them to remain dormant and yet quickly respond to appropriate proliferative stimuli. PMID:28812580

  11. Expression of Lactate Dehydrogenase in Aspergillus niger for L-Lactic Acid Production

    PubMed Central

    Dave, Khyati K.; Punekar, Narayan S.

    2015-01-01

    Different engineered organisms have been used to produce L-lactate. Poor yields of lactate at low pH and expensive downstream processing remain as bottlenecks. Aspergillus niger is a prolific citrate producer and a remarkably acid tolerant fungus. Neither a functional lactate dehydrogenase (LDH) from nor lactate production by A. niger is reported. Its genome was also investigated for the presence of a functional ldh. The endogenous A. niger citrate synthase promoter relevant to A. niger acidogenic metabolism was employed to drive constitutive expression of mouse lactate dehydrogenase (mldhA). An appraisal of different branches of the A. niger pyruvate node guided the choice of mldhA for heterologous expression. A high copy number transformant C12 strain, displaying highest LDH specific activity, was analyzed under different growth conditions. The C12 strain produced 7.7 g/l of extracellular L-lactate from 60 g/l of glucose, in non-neutralizing minimal media. Significantly, lactate and citrate accumulated under two different growth conditions. Already an established acidogenic platform, A. niger now promises to be a valuable host for lactate production. PMID:26683313

  12. Catalytic properties of thermophilic lactate dehydrogenase and halophilic malate dehydrogenase at high temperature and low water activity.

    PubMed

    Hecht, K; Wrba, A; Jaenicke, R

    1989-07-15

    Thermophilic lactate dehydrogenases from Thermotoga maritima and Bacillus stearothermophilus are stable up to temperature limits close to the optimum growth temperature of their parent organisms. Their catalytic properties are anomalous in that Km shows a drastic increase with increasing temperature. At low temperatures, the effect levels off. Extreme halophilic malate dehydrogenase from Halobacterium marismortui exhibits a similar anomaly. Increasing salt concentration (NaCl) leads to an optimum curve for Km, oxaloacctate while Km, NADH remains constant. Previous claims that the activity of halophilic malate dehydrogenase shows a maximum at 1.25 M NaCl are caused by limiting substrate concentration; at substrate saturation, specific activity of halophilic malate dehydrogenase reaches a constant value at ionic strengths I greater than or equal to 1 M. Non-halophilic (mitochondrial) malate dehydrogenase shows Km characteristics similar to those observed for the halophilic enzyme. The drastic decrease in specific activity of the mitochondrial enzyme at elevated salt concentrations is caused by the salt-induced increase in rigidity of the enzyme, rather than gross structural changes.

  13. Pyruvate dehydrogenase complex and lactate dehydrogenase are targets for therapy of acute liver failure.

    PubMed

    Ferriero, Rosa; Nusco, Edoardo; De Cegli, Rossella; Carissimo, Annamaria; Manco, Giuseppe; Brunetti-Pierri, Nicola

    2018-03-24

    Acute liver failure is a rapidly progressive deterioration of hepatic function resulting in high mortality and morbidity. Metabolic enzymes can translocate to the nucleus to regulate histone acetylation and gene expression. Levels and activities of pyruvate dehydrogenase complex (PDHC) and lactate dehydrogenase (LDH) were evaluated in nuclear fractions of livers of mice exposed to various hepatotoxins including CD95-antibody, α-amanitin, and acetaminophen. Whole-genome gene expression profiling by RNA-seq was performed in livers of mice with acute liver failure and analyzed by gene ontology enrichment analysis. Cell viability was evaluated in cell lines knocked-down for PDHA1 or LDH-A and in cells incubated with the LDH inhibitor galloflavin after treatment with CD95-antibody. We evaluated whether the histone acetyltransferase inhibitor garcinol or galloflavin could reduce liver damage in mice with acute liver failure. Levels and activities of PDHC and LDH were increased in nuclear fractions of livers of mice with acute liver failure. The increase of nuclear PDHC and LDH was associated with increased concentrations of acetyl-CoA and lactate in nuclear fractions, and histone H3 hyper-acetylation. Gene expression in livers of mice with acute liver failure suggested that increased histone H3 acetylation induces the expression of genes related to damage response. Reduced histone acetylation by the histone acetyltransferase inhibitor garcinol decreased liver damage and improved survival in mice with acute liver failure. Knock-down of PDHC or LDH improved viability in cells exposed to a pro-apoptotic stimulus. Treatment with the LDH inhibitor galloflavin that was also found to inhibit PDHC, reduced hepatic necrosis, apoptosis, and expression of pro-inflammatory cytokines in mice with acute liver failure. Mice treated with galloflavin also showed a dose-response increase in survival. PDHC and LDH translocate to the nucleus, leading to increased nuclear concentrations of

  14. 21 CFR 862.1440 - Lactate dehydrogenase test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lactate dehydrogenase test system. 862.1440 Section 862.1440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test...

  15. Prognostic significance of serum lactate dehydrogenase levels in Ewing's sarcoma: A meta-analysis.

    PubMed

    Li, Suoyuan; Yang, Qing; Wang, Hongsheng; Wang, Zhuoying; Zuo, Dongqing; Cai, Zhengdong; Hua, Yingqi

    2016-12-01

    A number of studies have investigated the role of serum lactate dehydrogenase (LDH) levels in patients with Ewing's sarcoma, although these have yielded inconsistent and inconclusive results. Therefore, the present study aimed to systematically review the published studies and conduct a meta-analysis to assess its prognostic value more precisely. Cohort studies assessing the prognostic role of LDH levels in patients with Ewing's sarcoma were included. A pooled hazard ratio (HR) with 95% confidence intervals (CIs) of overall survival (OS) or 5-year disease-free survival (DFS) was used to assess the prognostic role of the levels of serum LDH. Nine studies published between 1980 and 2014, with a total of 1,412 patients with Ewing's sarcoma, were included. Six studies, with a total of 644 patients, used OS as the primary endpoint and four studies, with 795 patients, used 5-year DFS. Overall, the pooled HR evaluating high LDH levels was 2.90 (95% CI: 2.09-4.04) for OS and 2.40 (95% CI: 1.93-2.98) for 5-year DFS. This meta-analysis demonstrates that high levels of serum LDH are associated with lower OS and 5-year DFS rates in patients with Ewing's sarcoma. Therefore, serum LDH levels are an effective biomarker of Ewing's sarcoma prognosis.

  16. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae)

    PubMed Central

    Wang, Yang; Wei, Lian; Wei, Dengbang; Li, Xiao; Xu, Lina; Wei, Linna

    2016-01-01

    Testis-specific lactate dehydrogenase (LDH-C4) is one of the lactate dehydrogenase (LDH) isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae) belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4), Lactate Dehydrogenase B4 (LDH-B4), and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis (PAGE). The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km) of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki) of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L), LDH-B4 (Ki = 23.800 mmol/L), and LDH-C4 (Ki = 65.500 mmol/L). These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4. PMID:26751442

  17. 21 CFR 862.1445 - Lactate dehydrogenase isoenzymes test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lactate dehydrogenase isoenzymes test system. 862.1445 Section 862.1445 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  18. Peroxisomal lactate dehydrogenase is generated by translational readthrough in mammals

    PubMed Central

    Schueren, Fabian; Lingner, Thomas; George, Rosemol; Hofhuis, Julia; Dickel, Corinna; Gärtner, Jutta; Thoms, Sven

    2014-01-01

    Translational readthrough gives rise to low abundance proteins with C-terminal extensions beyond the stop codon. To identify functional translational readthrough, we estimated the readthrough propensity (RTP) of all stop codon contexts of the human genome by a new regression model in silico, identified a nucleotide consensus motif for high RTP by using this model, and analyzed all readthrough extensions in silico with a new predictor for peroxisomal targeting signal type 1 (PTS1). Lactate dehydrogenase B (LDHB) showed the highest combined RTP and PTS1 probability. Experimentally we show that at least 1.6% of the total cellular LDHB is targeted to the peroxisome by a conserved hidden PTS1. The readthrough-extended lactate dehydrogenase subunit LDHBx can also co-import LDHA, the other LDH subunit, into peroxisomes. Peroxisomal LDH is conserved in mammals and likely contributes to redox equivalent regeneration in peroxisomes. DOI: http://dx.doi.org/10.7554/eLife.03640.001 PMID:25247702

  19. Insufficient filling of vacuum tubes as a cause of microhemolysis and elevated serum lactate dehydrogenase levels. Use of a data-mining technique in evaluation of questionable laboratory test results.

    PubMed

    Tamechika, Yoshie; Iwatani, Yoshinori; Tohyama, Kaoru; Ichihara, Kiyoshi

    2006-01-01

    Experienced physicians noted unexpectedly elevated concentrations of lactate dehydrogenase in some patient samples, but quality control specimens showed no bias. To evaluate this problem, we used a "latent reference individual extraction method", designed to obtain reference intervals from a laboratory database by excluding individuals who have abnormal results for basic analytes other than the analyte in question, in this case lactate dehydrogenase. The reference interval derived for the suspected year was 264-530 U/L, while that of the previous year was 248-495 U/L. The only change we found was the introduction of an order entry system, which requests precise sampling volumes rather than complete filling of vacuum tubes. The effect of vacuum persistence was tested using ten freshly drawn blood samples. Compared with complete filling, 1/5 filling resulted in average elevations of lactate dehydrogenase, aspartic aminotransferase, and potassium levels of 8.0%, 3.8%, and 3.4%, respectively (all p<0.01). Microhemolysis was confirmed using a urine stick method. The length of time before centrifugation determined the degree of hemolysis, while vacuum during centrifugation did not affect it. Microhemolysis is the probable cause of the suspected pseudo-elevation noted by the physicians. Data-mining methodology represents a valuable tool for monitoring long-term bias in laboratory results.

  20. A Bacterial Multidomain NAD-Independent d-Lactate Dehydrogenase Utilizes Flavin Adenine Dinucleotide and Fe-S Clusters as Cofactors and Quinone as an Electron Acceptor for d-Lactate Oxidization

    PubMed Central

    Jiang, Tianyi; Guo, Xiaoting; Yan, Jinxin; Zhang, Yingxin; Wang, Yujiao; Zhang, Manman; Sheng, Binbin; Ma, Cuiqing; Xu, Ping

    2017-01-01

    ABSTRACT Bacterial membrane-associated NAD-independent d-lactate dehydrogenase (Fe-S d-iLDH) oxidizes d-lactate into pyruvate. A sequence analysis of the enzyme reveals that it contains an Fe-S oxidoreductase domain in addition to a flavin adenine dinucleotide (FAD)-containing dehydrogenase domain, which differs from other typical d-iLDHs. Fe-S d-iLDH from Pseudomonas putida KT2440 was purified as a His-tagged protein and characterized in detail. This monomeric enzyme exhibited activities with l-lactate and several d-2-hydroxyacids. Quinone was shown to be the preferred electron acceptor of the enzyme. The two domains of the enzyme were then heterologously expressed and purified separately. The Fe-S cluster-binding motifs predicted by sequence alignment were preliminarily verified by site-directed mutagenesis of the Fe-S oxidoreductase domain. The FAD-containing dehydrogenase domain retained 2-hydroxyacid-oxidizing activity, although it decreased compared to the full Fe-S d-iLDH. Compared to the intact enzyme, the FAD-containing dehydrogenase domain showed increased catalytic efficiency with cytochrome c as the electron acceptor, but it completely lost the ability to use coenzyme Q10. Additionally, the FAD-containing dehydrogenase domain was no longer associated with the cell membrane, and it could not support the utilization of d-lactate as a carbon source. Based on the results obtained, we conclude that the Fe-S oxidoreductase domain functions as an electron transfer component to facilitate the utilization of quinone as an electron acceptor by Fe-S d-iLDH, and it helps the enzyme associate with the cell membrane. These functions make the Fe-S oxidoreductase domain crucial for the in vivo d-lactate utilization function of Fe-S d-iLDH. IMPORTANCE Lactate metabolism plays versatile roles in most domains of life. Lactate utilization processes depend on certain enzymes to oxidize lactate to pyruvate. In recent years, novel bacterial lactate-oxidizing enzymes have been

  1. Lactate dehydrogenase activity is inhibited by methylmalonate in vitro.

    PubMed

    Saad, Laura O; Mirandola, Sandra R; Maciel, Evelise N; Castilho, Roger F

    2006-04-01

    Methylmalonic acidemia (MMAemia) is an inherited metabolic disorder of branched amino acid and odd-chain fatty acid metabolism, involving a defect in the conversion of methylmalonyl-coenzyme A to succinyl-coenzyme A. Systemic and neurological manifestations in this disease are thought to be associated with the accumulation of methylmalonate (MMA) in tissues and biological fluids with consequent impairment of energy metabolism and oxidative stress. In the present work we studied the effect of MMA and two other inhibitors of mitochondrial respiratory chain complex II (malonate and 3-nitropropionate) on the activity of lactate dehydrogenase (LDH) in tissue homogenates from adult rats. MMA potently inhibited LDH-catalyzed conversion of lactate to pyruvate in liver and brain homogenates as well as in a purified bovine heart LDH preparation. LDH was about one order of magnitude less sensitive to inhibition by MMA when catalyzing the conversion of pyruvate to lactate. Kinetic studies on the inhibition of brain LDH indicated that MMA inhibits this enzyme competitively with lactate as a substrate (K (i)=3.02+/-0.59 mM). Malonate and 3-nitropropionate also strongly inhibited LDH-catalyzed conversion of lactate to pyruvate in brain homogenates, while no inhibition was observed by succinate or propionate, when present in concentrations of up to 25 mM. We propose that inhibition of the lactate/pyruvate conversion by MMA contributes to lactate accumulation in blood, metabolic acidemia and inhibition of gluconeogenesis observed in patients with MMAemia. Moreover, the inhibition of LDH in the central nervous system may also impair the lactate shuttle between astrocytes and neurons, compromising neuronal energy metabolism.

  2. Properties of lactate dehydrogenase from the isopod, Saduria entomon.

    PubMed

    Mulkiewicz, E; Zietara, M S; Stachowiak, K; Skorkowski, E F

    2000-07-01

    Saduria entomon lactate dehydrogenase (LDH-A4*) from thorax muscle was purified about 89 fold to specific activity 510 micromol NADH/min/mg using Cibacron Blue 3GA Agarose and Oxamate-Agarose chromatographies. The enzyme is a tetramer, with molecular weight of 140 kDa for the native enzyme and 36 kDa for the subunit. The isoelectric point was at pH 5.7. The enzyme possesses high heat stability (T50 = 71.5 degrees C). The optimum pH for pyruvate reduction reaction was 6.5, while for lactate oxidation one, the maximum activity was at pH 9.1. The Km for pyruvate was minimal at 5 degrees C, the average environmental temperature of the isopod. The Km values determined at 30 degrees C and optimal pH for pyruvate reduction and lactate oxidation were 0.18 and 90.04 mM, respectively. Amino acid compositional analyses showed the strongest resemblance of the isopod isoenzyme to cod (Gadus morhua) LDH-C4.

  3. LDHk, an unusual oxygen-sensitive lactate dehydrogenase expressed in human cancer.

    PubMed Central

    Anderson, G R; Kovacik, W P

    1981-01-01

    An unusual isozyme of lactate dehydrogenase (LDH; L-lactate:NAD+ oxidoreductase, EC 1.1.1.27), LDHk, has been described in cells transformed by the Kirsten murine sarcoma virus (KiMSV). This isozyme appears to contain one or more subunits encoded by the transforming gene of KiMSV and is readily distinguished from other isozymes of LDH. Specifically, it is more basic than other LDH isozymes, has an apparent subunit structure of (35,000)4(22,000)1, is essentially inactive if assayed under a normal atmosphere, and is strongly inhibited by GTP and various related compounds. We have examined human cancer and normal tissue controls for expression of an activity like LDHk. In 11 out of 16 human carcinomas, LDHk activity was increased 10- to 500-fold over the level seen in adjoining nontumor tissue. In contrast, other LDH isozymes were increased by only 2- to 5-fold. Images PMID:6942426

  4. Age related rise in lactate and its correlation with lactate dehydrogenase (LDH) status in post-mitochondrial fractions isolated from different regions of brain in mice.

    PubMed

    Datta, Siddhartha; Chakrabarti, Nilkanta

    2018-04-18

    Rise in brain lactate is the hallmark of ageing. Separate studies report that ageing is associated with elevation of lactate level and alterations of lactate dehydrogenase (LDH)-A/B mRNA-expression-ratio in cerebral cortex and hippocampus. However, age related lactate rise in brain and its association with LDH status and their brain regional variations are still elusive. In the present study, level of lactate, LDH (A and B) activity and LDH-A expression were evaluated in post-mitochondrial fraction of tissues isolated from four different brain regions (cerebral cortex, hippocampus, substantia nigra and cerebellum) of young and aged mice. Lactate levels elevated in four brain regions with maximum rise in substantia nigra of aged mice. LDH-A protein expression and its activity decreased in cerebral cortex, hippocampus and substantia nigra without any changes of these parameters in cerebellum of aged mice. LDH-B activity decreased in hippocampus, substantia nigra and cerebellum whereas its activity remains unaltered in cerebral cortex of aged mice. Accordingly, the ratio of LDH-A/LDH-B-activity remains unaltered in hippocampus and substantia nigra, decreased in cerebral cortex and increased in cerebellum. Therefore, rise of lactate in three brain regions (cerebral cortex, hippocampus, substantia nigra) appeared to be not correlated with the alterations of its regulatory enzymes activities in these three brain regions, rather it supports the fact of involvement of other mechanisms, like lactate transport and/or aerobic/anaerobic metabolism as the possible cause(s) of lactate rise in these three brain regions. The increase in LDH-A/LDH-B-activity-ratio appeared to be positively correlated with elevated lactate level in cerebellum of aged mice. Overall, the present study indicates that the mechanism of rise in lactate in brain varies with brain regions where LDH status plays an important role during ageing. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Reduction of ammonia and lactate through the coupling of glutamine synthetase selection and downregulation of lactate dehydrogenase-A in CHO cells.

    PubMed

    Noh, Soo Min; Park, Jin Hyoung; Lim, Myung Sin; Kim, Jong Won; Lee, Gyun Min

    2017-02-01

    Chinese hamster ovary (CHO) cell cultivation for production of therapeutic proteins is accompanied by production of metabolic wastes, mostly ammonia and lactate. To reduce ammonia production, the glutamine synthetase (GS) system was used to develop therapeutic monoclonal antibody (mAb)-producing CHO cells (SM-0.025). Additionally, the lactate dehydrogenase-A (LDH-A) was downregulated with shRNA to reduce lactate production in SM-0.025. The resulting mAb-producing cell lines (#2, #46, and #52) produced less ammonia than the host cell line during the exponential phase due to GS protein overexpression. LDH-A downregulation in SM-0.025 not only reduced lactate production but also further reduced ammonia production. Among the three LDH-A-downregulated clones, clone #2 had the highest mAb production along with significantly reduced specific lactate and ammonia production rates compared to those in SM-0.025. Waste reduction increased the galactosylation level of N-glycosylation, which improved mAb quality. LDH-A downregulation was also successfully applied to the host cell lines (CHO K1 and GS knockout CHO-K1). However, LDH-A downregulated host cells could not survive the pool-selection process wherein glutamine was excluded and methionine sulfoximine was added to the media. Taken together, LDH-A downregulation in the mAb-producing cell line generated with the GS system successfully reduced both ammonia and lactate levels, improving mAb galactosylation. However, LDH-A downregulation could not be applied to host cell lines because it hampered the selection process of the GS system.

  6. Overproduction and nucleotide sequence of the respiratory D-lactate dehydrogenase of Escherichia coli.

    PubMed Central

    Rule, G S; Pratt, E A; Chin, C C; Wold, F; Ho, C

    1985-01-01

    Recombinant DNA plasmids containing the gene for the membrane-bound D-lactate dehydrogenase (D-LDH) of Escherichia coli linked to the promoter PL from lambda were constructed. After induction, the levels of D-LDH were elevated 300-fold over that of the wild type and amounted to 35% of the total cellular protein. The nucleotide sequence of the D-LDH gene was determined and shown to agree with the amino acid composition and the amino-terminal sequence of the purified enzyme. Removal of the amino-terminal formyl-Met from D-LDH was not inhibited in cells which contained these high levels of D-LDH. Images PMID:3882663

  7. Purification, properties and immunological relationship of L (+)-lactate dehydrogenase from Lactobacillus casei.

    PubMed

    Gordon, G L; Doelle, H W

    1976-08-16

    The fructose-1,6-bisphosphate-activated L-lactate dehydrogenase (EC 1.1.1.27) from Lactobacillus casei ATCC 393 has been purified to homogenity by including affinity chromatography (cibacronblue-Sephadex-G-200) and preparative polyacrylamide gel electrophoresis into the purification procedures. The enzyme has an Mr of 132000-135000 with a subunit Mr of 34000. The pH optimum was found to be 5.4 insodium acetate buffer. Tris/maleate and citrate/phosphate buffers inhibited enzyme activity at this pH. The enzyme was completely inactivated by a temperature increase from 60 degrees C to 70 degrees C. Pyruvate saturation curves were sigmoidal in the absence of fructose 1,6-bisphosphate. In the presence of 20 muM fructose 1,6-bisphosphate a Km of 1.0 mM for pyruvate was obtained, whereas fructose 1,6-bisphosphate had no effect on the Km of 0.01 mM for NADH. The use of pyruvate analogues revealed two types of pyruvate binding sites, a catalytic and an effector site. The enzyme from L. casei appears to be subject to strict metabolic control, since ADP, ATP, dihydroxyacetone phosphate and 6-phosphogluconate are strong inhibitors. Immunodiffusion experiments with a rabbit antiserum to L. casei lactate dehydrogenase revealed that L. casei ATCC 393 L (+)-lactate dehydrogenase is probably not immunologically related to group D and group N streptococci. Of 24 lactic acid bacterial strains tested only 5 strains did cross-react: L. casei ATCC 393 = L. casei var. rhamnosus ATCC 7469 - L. casei var. alactosus NCDO 680 greater than L. casei UQM 95 greater than L. plantarum ATCC 14917.

  8. Deletion of lactate dehydrogenase in Enterobacter aerogenes to enhance 2,3-butanediol production.

    PubMed

    Jung, Moo-Young; Ng, Chiam Yu; Song, Hyohak; Lee, Jinwon; Oh, Min-Kyu

    2012-07-01

    2,3-Butanediol is an important bio-based chemical product, because it can be converted into several C4 industrial chemicals. In this study, a lactate dehydrogenase-deleted mutant was constructed to improve 2,3-butanediol productivity in Enterobacter aerogenes. To delete the gene encoding lactate dehydrogenase, λ Red recombination method was successfully adapted for E. aerogenes. The resulting strain produced a very small amount of lactate and 16.7% more 2,3-butanediol than that of the wild-type strain in batch fermentation. The mutant and its parental strain were then cultured with six different carbon sources, and the mutant showed higher carbon source consumption and microbial growth rates in all media. The 2,3-butanediol titer reached 69.5 g/l in 54 h during fed-batch fermentation with the mutant,which was 27.4% higher than that with the parental strain.With further optimization of the medium and aeration conditions,118.05 g/l 2,3-butanediol was produced in 54 h during fed-batch fermentation with the mutant. This is by far the highest titer of 2,3-butanediol with E. aerogenes achieved by metabolic pathway engineering.

  9. Diammonium phosphate stimulates transcription of L-lactate dehydrogenase leading to increased L-lactate production in the thermotolerant Bacillus coagulans strain.

    PubMed

    Sun, Lifan; Li, Yanfeng; Wang, Limin; Wang, Yanping; Yu, Bo

    2016-08-01

    Exploration of cost-effective fermentation substrates for efficient lactate production is an important economic objective. Although some organic nitrogen sources are also cheaper, inorganic nitrogen salts for lactate fermentation have additional advantages in facilitating downstream procedures and significantly improving the commercial competitiveness of lactate production. In this study, we first established an application of diammonium phosphate to replace yeast extract with a reduced 90 % nitrogen cost for a thermotolerant Bacillus coagulans strain. In vivo enzymatic and transcriptional analyses demonstrated that diammonium phosphate stimulates the gene expression of L-lactate dehydrogenase, thus providing higher specific enzyme activity in vivo and increasing L-lactic acid production. This new information provides a foundation for establishing a cost-effective process for polymer-grade L-lactic acid production in an industrial setting.

  10. [Characterization of D-lactate dehydrogenase isozymes from a D-lactic acid producing bacterium Sporolactobacillus inulinus].

    PubMed

    Zhang, Danru; Zheng, Lu; Wu, Bin; He, Bingfang

    2016-11-04

    Sporolactobacillus inulinus, a typical homofermentative lactic acid bacterium, is an efficient D-lactic acid producer. Various environment factors affect the productivity of S. inulinus. Glucokinase, phosphofructokinase, pyruvate kinase and lactic dehydrogenase are the key enzymes of D-lactic acid production from glucose by S. inulinus. The characteristics of these enzymes are important in controlling and regulating the fermentation process. According to the genome bioinformatics analysis of S. inulinus CASD, three putative D-lactate dehydrogenases were identified, among which the bifunctional protein had been reported. In this study, we provided insights into the characteristics of the other two D-lactate dehydrogenase isozymes. S. inulinus Y2-8 genome was used as the template to amplify D-lactate dehydrogenase gene (dldh) and D-isomer specific 2-hydroxyacid dehydrogenase gene (dhdh). The two recombinant strains E-pET-28a/dldh and E-pET-28a/dhdh were constructed for enzyme expression. Both recombinants DLDH and DHDH could convert pyruvic acid into D-lactic acid. Enzymes expressed by recombinant strains were purified by Ni-NTA chromatography. The apparent molecular mass of DLDH was approximately 37 kDa by SDS-PAGE analysis, and DLDH showed a high affinity to pyruvate with the Km value of (0.58±0.04) mmol/L. The optimal reaction temperature and pH for DLDH was 35℃ and 6.5, respectively. The apparent molecular mass of DHDH was approximately 39 kDa, and the Km of DHDH toward pyruvate was (1.70±0.08) mmol/L. The optimum catalysis temperature and pH of DHDH were 30℃ and 7.5, respectively. According to the Km and optimal reaction pH, DLDH was suggested as the main catalyst in formation D-lactic acid from pyruvate during the fermentation. The enzymatic properties would contribute to the regulation of the fermentation of S. inulinus.

  11. Fragment growing and linking lead to novel nanomolar lactate dehydrogenase inhibitors.

    PubMed

    Kohlmann, Anna; Zech, Stephan G; Li, Feng; Zhou, Tianjun; Squillace, Rachel M; Commodore, Lois; Greenfield, Matthew T; Lu, Xiaohui; Miller, David P; Huang, Wei-Sheng; Qi, Jiwei; Thomas, R Mathew; Wang, Yihan; Zhang, Sen; Dodd, Rory; Liu, Shuangying; Xu, Rongsong; Xu, Yongjin; Miret, Juan J; Rivera, Victor; Clackson, Tim; Shakespeare, William C; Zhu, Xiaotian; Dalgarno, David C

    2013-02-14

    Lactate dehydrogenase A (LDH-A) catalyzes the interconversion of lactate and pyruvate in the glycolysis pathway. Cancer cells rely heavily on glycolysis instead of oxidative phosphorylation to generate ATP, a phenomenon known as the Warburg effect. The inhibition of LDH-A by small molecules is therefore of interest for potential cancer treatments. We describe the identification and optimization of LDH-A inhibitors by fragment-based drug discovery. We applied ligand based NMR screening to identify low affinity fragments binding to LDH-A. The dissociation constants (K(d)) and enzyme inhibition (IC(50)) of fragment hits were measured by surface plasmon resonance (SPR) and enzyme assays, respectively. The binding modes of selected fragments were investigated by X-ray crystallography. Fragment growing and linking, followed by chemical optimization, resulted in nanomolar LDH-A inhibitors that demonstrated stoichiometric binding to LDH-A. Selected molecules inhibited lactate production in cells, suggesting target-specific inhibition in cancer cell lines.

  12. Ultrafiltration-LC-MS combined with semi-preparative HPLC for the simultaneous screening and isolation of lactate dehydrogenase inhibitors from Belamcanda chinensis.

    PubMed

    Li, Senlin; Li, Sainan; Tang, Ying; Liu, Chunming; Chen, Lina; Zhang, Yuchi

    2016-12-01

    Stroke represents the fourth leading cause of death in the USA and the second leading cause of death worldwide. Lactate dehydrogenase inhibitors are widely used in the treatment of ischemic stroke and natural products are considered a promising source of novel lactate dehydrogenase inhibitors. In this study, we used PC12 cells to determine the protective effect of extracts from the herb Belamcanda chinensis following toxic challenge. Using ultrafiltration high-performance liquid chromatography coupled with photo-diode array detection and electrospray ionization mass spectrometry, we screened and identified isoflavonoids from Belamcanda chinensis extracts. Semi-preparative high-performance liquid chromatography was then applied to separate and isolate the active constituents. Using these methods, we identified six major compounds in Belamcanda chinensis as lactate dehydrogenase inhibitors: tectoridin, iristectorin A, iridin, tectorigenin, irigenin, and irisflorentin, which were then isolated to >92% purity. This is the first report that Belamcanda chinensis extracts contain potent lactate dehydrogenase inhibitors. Our results demonstrate that the systematic isolation of bioactive components from Belamcanda chinensis guided by ultrafiltration high-performance liquid chromatography coupled with photo-diode array detection and electrospray ionization mass spectrometry represents a feasible and efficient technique that could be extended for the identification and isolation of other enzyme inhibitors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Positive selection on D-lactate dehydrogenases of Lactobacillus delbrueckii subspecies bulgaricus.

    PubMed

    Zhang, Jifeng; Gong, Guangyu; Wang, Xiao; Zhang, Hao; Tian, Weidong

    2015-08-01

    Lactobacillus delbrueckii has been widely used for yogurt fermentation. It has genes encoding both D- and L-type lactate dehydrogenases (LDHs) that catalyse the production of L(+) or D(-) stereoisomer of lactic acid. D-lactic acid is the primary lactate product by L. delbrueckii, yet it cannot be metabolised by human intestine. Since it has been domesticated for long time, an interesting question arises regarding to whether the selection pressure has affected the evolution of both L-LDH and D-LDH genes in the genome. To answer this question, in this study the authors first investigated the evolution of these two genes by constructing phylogenetic trees. They found that D-LDH-based phylogenetic tree could better represent the phylogenetic relationship in the acidophilus complex than L-LDH-based tree. They next investigated the evolutions of LDH genes of L. delbrueckii at amino acid level, and found that D-LDH gene in L. delbrueckii is positively selected, possibly a consequence of long-term domestication. They further identified four amino acids that are under positive selection. One of them, V261, is located at the centre of three catalytic active sites, indicating likely functional effects on the enzyme activity. The selection from the domestication process thus provides direction for future engineering of D-LDH.

  14. Some Lactobacillus l-Lactate Dehydrogenases Exhibit Comparable Catalytic Activities for Pyruvate and Oxaloacetate

    PubMed Central

    Arai, Kazuhito; Kamata, Takeo; Uchikoba, Hiroyuki; Fushinobu, Shinya; Matsuzawa, Hiroshi; Taguchi, Hayao

    2001-01-01

    The nonallosteric and allosteric l-lactate dehydrogenases of Lactobacillus pentosus and L. casei, respectively, exhibited broad substrate specificities, giving virtually the same maximal reaction velocity and substrate Km values for pyruvate and oxaloacetate. Replacement of Pro101 with Asn reduced the activity of the L. pentosus enzyme toward these alternative substrates to a greater extent than the activity toward pyruvate. PMID:11114942

  15. Purification and Properties of White Muscle Lactate Dehydrogenase from the Anoxia-Tolerant Turtle, the Red-Eared Slider, Trachemys scripta elegans

    PubMed Central

    Dawson, Neal J.; Bell, Ryan A. V.; Storey, Kenneth B.

    2013-01-01

    Lactate dehydrogenase (LDH; E.C. 1.1.1.27) is a crucial enzyme involved in energy metabolism in muscle, facilitating the production of ATP via glycolysis during oxygen deprivation by recycling NAD+. The present study investigated purified LDH from the muscle of 20 h anoxic and normoxic T. s. elegans, and LDH from anoxic muscle showed a significantly lower (47%) K m for L-lactate and a higher V max value than the normoxic form. Several lines of evidence indicated that LDH was converted to a low phosphate form under anoxia: (a) stimulation of endogenously present protein phosphatases decreased the K m of L-lactate of control LDH to anoxic levels, whereas (b) stimulation of kinases increased the K m of L-lactate of anoxic LDH to normoxic levels, and (c) dot blot analysis shows significantly less serine (78%) and threonine (58%) phosphorylation in anoxic muscle LDH as compared to normoxic LDH. The physiological consequence of anoxia-induced LDH dephosphorylation appears to be an increase in LDH activity to promote the reduction of pyruvate in muscle tissue, converting the glycolytic end product to lactate to maintain a prolonged glycolytic flux under energy-stressed anoxic conditions. PMID:23533717

  16. Purification and Properties of White Muscle Lactate Dehydrogenase from the Anoxia-Tolerant Turtle, the Red-Eared Slider, Trachemys scripta elegans.

    PubMed

    Dawson, Neal J; Bell, Ryan A V; Storey, Kenneth B

    2013-01-01

    Lactate dehydrogenase (LDH; E.C. 1.1.1.27) is a crucial enzyme involved in energy metabolism in muscle, facilitating the production of ATP via glycolysis during oxygen deprivation by recycling NAD(+). The present study investigated purified LDH from the muscle of 20 h anoxic and normoxic T. s. elegans, and LDH from anoxic muscle showed a significantly lower (47%) K m for L-lactate and a higher V max value than the normoxic form. Several lines of evidence indicated that LDH was converted to a low phosphate form under anoxia: (a) stimulation of endogenously present protein phosphatases decreased the K m of L-lactate of control LDH to anoxic levels, whereas (b) stimulation of kinases increased the K m of L-lactate of anoxic LDH to normoxic levels, and (c) dot blot analysis shows significantly less serine (78%) and threonine (58%) phosphorylation in anoxic muscle LDH as compared to normoxic LDH. The physiological consequence of anoxia-induced LDH dephosphorylation appears to be an increase in LDH activity to promote the reduction of pyruvate in muscle tissue, converting the glycolytic end product to lactate to maintain a prolonged glycolytic flux under energy-stressed anoxic conditions.

  17. Plasma Lactate Dehydrogenase Levels Predict Mortality in Acute Aortic Syndromes

    PubMed Central

    Morello, Fulvio; Ravetti, Anna; Nazerian, Peiman; Liedl, Giovanni; Veglio, Maria Grazia; Battista, Stefania; Vanni, Simone; Pivetta, Emanuele; Montrucchio, Giuseppe; Mengozzi, Giulio; Rinaldi, Mauro; Moiraghi, Corrado; Lupia, Enrico

    2016-01-01

    Abstract In acute aortic syndromes (AAS), organ malperfusion represents a key event impacting both on diagnosis and outcome. Increased levels of plasma lactate dehydrogenase (LDH), a biomarker of malperfusion, have been reported in AAS, but the performance of LDH for the diagnosis of AAS and the relation of LDH with outcome in AAS have not been evaluated so far. This was a bi-centric prospective diagnostic accuracy study and a cohort outcome study. From 2008 to 2014, patients from 2 Emergency Departments suspected of having AAS underwent LDH assay at presentation. A final diagnosis was obtained by aortic imaging. Patients diagnosed with AAS were followed-up for in-hospital mortality. One thousand five hundred seventy-eight consecutive patients were clinically eligible, and 999 patients were included in the study. The final diagnosis was AAS in 201 (20.1%) patients. Median LDH was 424 U/L (interquartile range [IQR] 367–557) in patients with AAS and 383 U/L (IQR 331–460) in patients with alternative diagnoses (P < 0.001). Using a cutoff of 450 U/L, the sensitivity of LDH for AAS was 44% (95% confidence interval [CI] 37–51) and the specificity was 73% (95% CI 69–76). Overall in-hospital mortality for AAS was 23.8%. Mortality was 32.6% in patients with LDH ≥ 450 U/L and 16.8% in patients with LDH < 450 U/L (P = 0.006). Following stratification according to LDH quartiles, in-hospital mortality was 12% in the first (lowest) quartile, 18.4% in the second quartile, 23.5% in the third quartile, and 38% in the fourth (highest) quartile (P = 0.01). LDH ≥ 450 U/L was further identified as an independent predictor of death in AAS both in univariate and in stepwise logistic regression analyses (odds ratio 2.28, 95% CI 1.11–4.66; P = 0.025), in addition to well-established risk markers such as advanced age and hypotension. Subgroup analysis showed excess mortality in association with LDH ≥ 450 U/L in elderly, hemodynamically stable

  18. Lactate Dehydrogenase in Hepatocellular Carcinoma: Something Old, Something New.

    PubMed

    Faloppi, Luca; Bianconi, Maristella; Memeo, Riccardo; Casadei Gardini, Andrea; Giampieri, Riccardo; Bittoni, Alessandro; Andrikou, Kalliopi; Del Prete, Michela; Cascinu, Stefano; Scartozzi, Mario

    2016-01-01

    Hepatocellular carcinoma (HCC) is the most common primary liver tumour (80-90%) and represents more than 5.7% of all cancers. Although in recent years the therapeutic options for these patients have increased, clinical results are yet unsatisfactory and the prognosis remains dismal. Clinical or molecular criteria allowing a more accurate selection of patients are in fact largely lacking. Lactic dehydrogenase (LDH) is a glycolytic key enzyme in the conversion of pyruvate to lactate under anaerobic conditions. In preclinical models, upregulation of LDH has been suggested to ensure both an efficient anaerobic/glycolytic metabolism and a reduced dependence on oxygen under hypoxic conditions in tumour cells. Data from several analyses on different tumour types seem to suggest that LDH levels may be a significant prognostic factor. The role of LDH in HCC has been investigated by different authors in heterogeneous populations of patients. It has been tested as a potential biomarker in retrospective, small, and nonfocused studies in patients undergoing surgery, transarterial chemoembolization (TACE), and systemic therapy. In the major part of these studies, high LDH serum levels seem to predict a poorer outcome. We have reviewed literature in this setting trying to resume basis for future studies validating the role of LDH in this disease.

  19. Increasing the Heme-Dependent Respiratory Efficiency of Lactococcus lactis by Inhibition of Lactate Dehydrogenase

    PubMed Central

    Arioli, Stefania; Zambelli, Daniele; Guglielmetti, Simone; De Noni, Ivano; Pedersen, Martin B.; Pedersen, Per Dedenroth; Dal Bello, Fabio

    2013-01-01

    The discovery of heme-induced respiration in Lactococcus lactis has radically improved the industrial processes used for the biomass production of this species. Here, we show that inhibition of the lactate dehydrogenase activity of L. lactis during growth under respiration-permissive conditions can stimulate aerobic respiration, thereby increasing not only growth efficiency but also the robustness of this organism. PMID:23064338

  20. Nuclear lactate dehydrogenase modulates histone modification in human hepatocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Castonguay, Zachary; Auger, Christopher; Thomas, Sean C.

    Highlights: • Nuclear LDH is up-regulated under oxidative stress. • SIRT1 is co-immunoprecipitated bound to nuclear LDH. • Nuclear LDH is involved in histone deacetylation and epigenetics. - Abstract: It is becoming increasingly apparent that the nucleus harbors metabolic enzymes that affect genetic transforming events. Here, we describe a nuclear isoform of lactate dehydrogenase (nLDH) and its ability to orchestrate histone deacetylation by controlling the availability of nicotinamide adenine dinucleotide (NAD{sup +}), a key ingredient of the sirtuin-1 (SIRT1) deacetylase system. There was an increase in the expression of nLDH concomitant with the presence of hydrogen peroxide (H{sub 2}O{sub 2})more » in the culture medium. Under oxidative stress, the NAD{sup +} generated by nLDH resulted in the enhanced deacetylation of histones compared to the control hepatocytes despite no discernable change in the levels of SIRT1. There appeared to be an intimate association between nLDH and SIRT1 as these two enzymes co-immunoprecipitated. The ability of nLDH to regulate epigenetic modifications by manipulating NAD{sup +} reveals an intricate link between metabolism and the processing of genetic information.« less

  1. Salivary lactate dehydrogenase and aminotransferases in diabetic patients

    PubMed Central

    Malicka, Barbara; Skoskiewicz-Malinowska, Katarzyna; Kaczmarek, Urszula

    2016-01-01

    Abstract Diabetes mellitus (DM) is a group of metabolic diseases resulting from impaired insulin secretion and/or action. DM is characterized by hyperglycemia that can lead to the dysfunction or damage of organs, including the salivary glands. The aim of this study was to compare the levels of salivary lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in diabetic patients. The study was approved by the Bioethics Committee of Wroclaw Medical University (Poland). The study comprised 90 adults of both sexes, aged 21 to 57 years. The patients were divided into 3 groups: type 1 diabetics (D1), type 2 diabetics (D2), and a healthy control group (C). Each group consisted of 30 age- and sex-matched subjects. Total protein (P, by Lowry method), LDH, AST, ALT (with Alpha Diagnostics kits), and salivary flow rate were measured in unstimulated mixed saliva. The level of glycosylated hemoglobin (HbA1c) was measured with DCA 2000 Reagent Kit. The obtained data were analyzed using the Mann–Whitney U test and the Spearman rank at a significance level of P < 0.05 with the use of STATISTICA 9.0 software. In comparison with C, D1 presented a significantly higher activity of LDH (P < 0.001), AST (P < 0.001), and ALT (P < 0.01), whereas D2 indicated higher levels of LDH (P < 0.001) and ALT (P < 0.05) compared with C. Comparing D1 to D2, approximately 3-fold higher activity of AST (P < 0.01) and approximately 4.5-fold higher activity of ALT (P < 0.01) was observed. Higher levels of salivary LDH, AST, and ALT in D1 compared with D2 and C confirm that salivary glands of D1 might be attributed to autoimmunological damage associated with the pathomechanism of DM. PMID:27893660

  2. Salivary lactate dehydrogenase and aminotransferases in diabetic patients.

    PubMed

    Malicka, Barbara; Skoskiewicz-Malinowska, Katarzyna; Kaczmarek, Urszula

    2016-11-01

    Diabetes mellitus (DM) is a group of metabolic diseases resulting from impaired insulin secretion and/or action. DM is characterized by hyperglycemia that can lead to the dysfunction or damage of organs, including the salivary glands.The aim of this study was to compare the levels of salivary lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) in diabetic patients.The study was approved by the Bioethics Committee of Wroclaw Medical University (Poland). The study comprised 90 adults of both sexes, aged 21 to 57 years. The patients were divided into 3 groups: type 1 diabetics (D1), type 2 diabetics (D2), and a healthy control group (C). Each group consisted of 30 age- and sex-matched subjects. Total protein (P, by Lowry method), LDH, AST, ALT (with Alpha Diagnostics kits), and salivary flow rate were measured in unstimulated mixed saliva. The level of glycosylated hemoglobin (HbA1c) was measured with DCA 2000 Reagent Kit. The obtained data were analyzed using the Mann-Whitney U test and the Spearman rank at a significance level of P < 0.05 with the use of STATISTICA 9.0 software.In comparison with C, D1 presented a significantly higher activity of LDH (P < 0.001), AST (P < 0.001), and ALT (P < 0.01), whereas D2 indicated higher levels of LDH (P < 0.001) and ALT (P < 0.05) compared with C. Comparing D1 to D2, approximately 3-fold higher activity of AST (P < 0.01) and approximately 4.5-fold higher activity of ALT (P < 0.01) was observed.Higher levels of salivary LDH, AST, and ALT in D1 compared with D2 and C confirm that salivary glands of D1 might be attributed to autoimmunological damage associated with the pathomechanism of DM.

  3. Purification and Electrophoretic Characterization of Lactate Dehydrogenase from Mammalian Blood: A Different Twist on a Classic Experiment

    ERIC Educational Resources Information Center

    Brunauer, Linda S.

    2016-01-01

    A multiweek protein purification suite, suitable for upper-division biochemistry or biotechnology undergraduate students, is described. Students work in small teams to isolate the enzyme lactate dehydrogenase (LDH) from a nontraditional tissue source, mammalian blood, using a sequence of three column chromatographic procedures: ion-exchange, size…

  4. Effect of chlorocamphene on the isoenzyme spectrum of lactate dehydrogenase in rat serum and liver.

    PubMed Central

    Kuz'minskaya, U A; Alekhina, S M

    1976-01-01

    Rats were used to study the general activity and the isoenzyme spectrum of lactate dehydrogenase (LDH) during single-instance and long-term introduction of polychlorocamphene. Total lactate dehydrogenase activity decreases in the liver during the single-instance introduction of half the LD50 (120 mg/kg). The isoenzyme spectrum of LDH is characterized by an increase in the quantity of LDH1, LDH2, and LDH3 and by a decrease in the amount of LDH4. The overall LDH activity does not change in blood serum. The isoform ratio changes insignificantly and LDH1 falls, but normalized 15 days after the introduction of the compound. Long-term introduction of polychlorocamphene at levels 1/100 the LD50 dose over 1.3 and 6 months causes a reduction in the overall LDH activity, both in the liver and in the serum. A decrease in the activity of the basic LDH isoenzyme of the liver (LDH5) and a sharp increase in LDH3 are characteristic for the isoenzyme spectrum of the liver. LDH1 and LDH4 decrease and LDH2 and LDH3 increase in blood serum. Beginning with the third month of polychlorocamphene introduction, LDH1 tends to return to normal levels. LDH2, LDH3, and LDH4 do return to normal levels, while LDH5 increases regularly. This results in a reduction of the number of H subunits and an increase of M subunits. This is characteristic of hypoxic states. On comparing the changes in the LDH enzymes of the liver and blood serum, it can be considered that the introduction of polychlorocamphene does not result in an increase in the permeability of the cellular membranes of the liver for LDH isoenzymes, while the observed isoenzyme spectrum shifts in blood serum are either the result of the biosynthesis of the isoforms of this enzyme changed by the compound or the result of the permeability for them of cells of other tissues. PMID:1269500

  5. Altered Kinetics Properties of Erythrocyte Lactate Dehydrogenase in Type II Diabetic Patients and Its Implications for Lactic Acidosis.

    PubMed

    Mali, Aniket V; Bhise, Sunita S; Katyare, Surendra S; Hegde, Mahabaleshwar V

    2018-01-01

    Recent studies have been noted that the erythrocytes from Type II diabetic patients show significantly altered structural and functional characteristics along with the changed intracellular concentrations of glycolytic intermediates. More recent studies from our laboratory have shown that the activities of enzymes of glycolytic pathway changed significantly in RBCs from Type II diabetic patients. In particular the levels of lactate dehydrogenase (LDH) increased significantly. Lactic acidosis is an established feature of diabetes and LDH plays a crucial role in conversion of pyruvate to lactate and reportedly, the levels of lactate are significantly high which is consistent with our observation on increased levels of LDH. Owing to this background, we examined the role of erythrocyte LDH in lactic acidosis by studying its kinetics properties in Type II diabetic patients. Km, Vmax and apparent catalytic efficiency were determined using pyruvate and NADH as the substrates. With pyruvate as the substrate the Km values were comparable but Vmax increased significantly in the diabetic group. With NADH as the substrate the enzyme activity of the diabetic group resolved in two components as against a single component in the controls. The Apparent Kcat and Kcat/Km values for pyruvate increased in the diabetic group. The Ki for pyruvate increased by two fold for the enzyme from diabetic group with a marginal decrease in Ki for NADH. The observed changes in catalytic attributes are conducive to enable the enzyme to carry the reaction in forward direction towards conversion of pyruvate to lactate leading to lactic acidosis.

  6. Radiation-induced enzyme efflux from rat heart: sedentary animals. [Gamma radiation, lactate dehydrogenase, creative kinase, glutamate oxaloacetate transaminase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    MacWilliam, L.D.; Bhakthan, N.M.G.

    1976-01-01

    Serum levels of lactate dehydrogenase, creatine kinase, and glutamate oxaloacetate transaminase show initial elevations within 12 hr of exposure to 2,000 rads of ..gamma..-radiation to the thoracic region of rats. Significant decreases in heart muscle homogenate levels of these enzymes parallel initial elevations in the serum and may suggest that enhanced leakage of enzymes is a consequence of radiation injury to heart muscle. Insignificant alterations in mitochondrial glutamate oxaloacetate transaminase levels after exposure indicate that in vivo injury to the mitochondria from therapeutic levels of ..gamma..-radiation is questionable. The results support the contention that ionizing radiation instigates alterations in themore » dynamic permeability of membranes, allowing leakage of biologically active material out of the injured cell.« less

  7. Lactate dehydrogenase inhibition: exploring possible applications beyond cancer treatment.

    PubMed

    Di Stefano, Giuseppina; Manerba, Marcella; Di Ianni, Lorenza; Fiume, Luigi

    2016-04-01

    Lactate dehydrogenase (LDH) inhibition is considered a worthwhile attempt in the development of innovative anticancer strategies. Unfortunately, in spite of the involvement of several research institutions and pharma-companies, the discovery of LDH inhibitors with drug-like properties seems a hardly resolvable challenge. While awaiting new advancements, in the present review we will examine other pathologic conditions characterized by increased glycolysis and LDH activity, which could potentially benefit from LDH inhibition. The rationale for targeting LDH activity in these contexts is the same justifying the LDH-based approach in anticancer therapy: because of the enzyme position at the end of glycolytic pathway, LDH inhibitors are not expected to hinder glucose metabolism of normal cells. Moreover, we will summarize the latest contributions in the discovery of enzyme inhibitors and try to glance over the reasons underlying the complexity of this research.

  8. Salivary lactate dehydrogenase levels can provide early diagnosis of hypoxic-ischaemic encephalopathy in neonates with birth asphyxia.

    PubMed

    Mehta, Akshay; Chawla, Deepak; Kaur, Jasbinder; Mahajan, Vidushi; Guglani, Vishal

    2015-06-01

    Timely detection of hypoxic-ischaemic encephalopathy (HIE) is crucial for selecting neonates who are likely to benefit from neuroprotective therapy. This study evaluated the efficacy of salivary lactate dehydrogenase (LDH) in the early diagnosis of HIE among neonates with perinatal asphyxia. We prospectively enrolled 30 neonates who needed resuscitation at birth or had a history of delayed cry into the HIE group if they developed HIE within 12 h of birth. The control group comprised 30 neonates who had no evidence of HIE, but had intrapartum foetal distress or needed resuscitation at birth. LDH was measured using saliva samples collected within 12 h of birth. Salivary LDH was significantly higher in the HIE group, with a median of 2578 and an interquartile range (IQR) of 1379-3408 international units per litre (IU/L), than in the control group (median 558.5, IQR: 348-924 IU/L, p < 0.001). The test demonstrated excellent discriminating ability: the area under the curve was 0.92 and the levels of 893 IU/L showed a sensitivity of 90% and a specificity of 73.3%. Measuring salivary LDH among neonates with birth asphyxia provided an early and accurate diagnosis of HIE and could be used as a triage tool. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  9. l-Lactate metabolism in HEP G2 cell mitochondria due to the l-lactate dehydrogenase determines the occurrence of the lactate/pyruvate shuttle and the appearance of oxaloacetate, malate and citrate outside mitochondria.

    PubMed

    Pizzuto, Roberto; Paventi, Gianluca; Porcile, Carola; Sarnataro, Daniela; Daniele, Aurora; Passarella, Salvatore

    2012-09-01

    As part of an ongoing study of l-lactate metabolism both in normal and in cancer cells, we investigated whether and how l-lactate metabolism occurs in mitochondria of human hepatocellular carcinoma (Hep G2) cells. We found that Hep G2 cell mitochondria (Hep G2-M) possess an l-lactate dehydrogenase (ml-LDH) restricted to the inner mitochondrial compartments as shown by immunological analysis, confocal microscopy and by assaying ml-LDH activity in solubilized mitochondria. Cytosolic and mitochondrial l-LDHs were found to differ from one another in their saturation kinetics. Having shown that l-lactate itself can enter Hep G2 cells, we found that Hep G2-M swell in ammonium l-lactate, but not in ammonium pyruvate solutions, in a manner inhibited by mersalyl, this showing the occurrence of a carrier-mediated l-lactate transport in these mitochondria. Occurrence of the l-lactate/pyruvate shuttle and the appearance outside mitochondria of oxaloacetate, malate and citrate arising from l-lactate uptake and metabolism together with the low oxygen consumption and membrane potential generation are in favor of an anaplerotic role for l-LAC in Hep G2-M. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. The Core of Allosteric Motion in Thermus caldophilus l-Lactate Dehydrogenase*

    PubMed Central

    Ikehara, Yoko; Arai, Kazuhito; Furukawa, Nayuta; Ohno, Tadashi; Miyake, Tatsuya; Fushinobu, Shinya; Nakajima, Masahiro; Miyanaga, Akimasa; Taguchi, Hayao

    2014-01-01

    For Thermus caldophilus l-lactate dehydrogenase (TcLDH), fructose 1,6-bisphosphate (FBP) reduced the pyruvate S0.5 value 103-fold and increased the Vmax value 4-fold at 30 °C and pH 7.0, indicating that TcLDH has a much more T state-sided allosteric equilibrium than Thermus thermophilus l-lactate dehydrogenase, which has only two amino acid replacements, A154G and H179Y. The inactive (T) and active (R) state structures of TcLDH were determined at 1.8 and 2.0 Å resolution, respectively. The structures indicated that two mobile regions, MR1 (positions 172–185) and MR2 (positions 211–221), form a compact core for allosteric motion, and His179 of MR1 forms constitutive hydrogen bonds with MR2. The Q4(R) mutation, which comprises the L67E, H68D, E178K, and A235R replacements, increased Vmax 4-fold but reduced pyruvate S0.5 only 5-fold in the reaction without FBP. In contrast, the P2 mutation, comprising the R173Q and R216L replacements, did not markedly increase Vmax, but 102-reduced pyruvate S0.5, and additively increased the FBP-independent activity of the Q4(R) enzyme. The two types of mutation consistently increased the thermal stability of the enzyme. The MR1-MR2 area is a positively charged cluster, and its center approaches another positively charged cluster (N domain cluster) across the Q-axis subunit interface by 5 Å, when the enzyme undergoes the T to R transition. Structural and kinetic analyses thus revealed the simple and unique allosteric machinery of TcLDH, where the MR1-MR2 area pivotally moves during the allosteric motion and mediates the allosteric equilibrium through electrostatic repulsion within the protein molecule. PMID:25258319

  11. The diagnostic significance of lactate dehydrogenase isoenzymes in urinary cytology.

    PubMed Central

    Nishikawa, A.; Tanaka, T.; Takeuchi, T.; Fujihiro, S.; Mori, H.

    1991-01-01

    Lactate dehydrogenase (LDH) isoenzyme distribution was examined in 106 urine samples being tested cytologically for evidence of bladder cancer; the samples were selected to have less than 20 leucocytes and erythrocytes per high power field and the LDH pattern determined by electrophoresis. The Papanicolaou stained-smears showed 68 negative, 17 suspicious and 21 positive. The LDH M-fraction of the urinary supernatant in cytologically positive cases was significantly greater than in negative cases, although the latter included a few false negative samples. Some of the false negatives gave positive results for the LDH M-fraction; these results suggest that the determination of LDH isoenzymes in the urine is useful in diagnosing urinary tract cancers, including early stage, and for follow-up of patients with bladder cancers after surgical resection. PMID:2039708

  12. Melanoma inhibiting activity protein (MIA), beta-2 microglobulin and lactate dehydrogenase (LDH) in metastatic melanoma.

    PubMed

    Cao, M González; Auge, J M; Molina, R; Martí, R; Carrera, C; Castel, T; Vilella, R; Conill, C; Sánchez, M; Malvehy, J; Puig, S

    2007-01-01

    Serum levels of melanoma markers may have a role in monitoring disease evolution in metastatic melanoma. Serial measurements of melanoma inhibiting activity protein (MIA), lactate dehydrogenase (LDH), S-100 and beta2-microglubulin were obtained from 42 metastatic melanoma patients during their biochemotherapy treatment. High pre-treatment serum levels of S-100, LDH, MIA and P2-microglobulin were detected in 50%, 57%, 50% and 24% of the patients, respectively. Only S-100 had prognostic significance for both disease-free (p=0.011) and overall survival (p=0.021). In patients who responded to treatment, S-100 levels decreased significantly from pre-treatment to the time of response (p = 0.050). When patients progressed, levels of MIA and P2-microglobulin increased significantly (p =0.028 and p =0.030, respectively). Correlation with disease evolution was found for S-100, MIA and P2-microglobulin levels. Despite the small sample size of the study, S-100 was a significant prognostic marker for overall survival and disease-free survival.

  13. Lactate Dehydrogenase Activity in Gingival Crevicular Fluid as a Marker in Orthodontic Tooth Movement

    PubMed Central

    Alfaqeeh, Sarah A; Anil, Sukumaran

    2011-01-01

    Objectives: This study aims at analyzing the changes in gingival crevicular fluid (GCF) lactate dehydrogenase (LDH) activity during orthodontic movement. Methods: Twenty patients all requiring first premolar extractions were selected and treated with conventional straight wire mechanotherapy. Canine retraction was done using 125 g Nitinol closed coil springs. The maxillary canine on one side served as the experimental site while the contralateral canine served as the control. GCF was collected from the canines before initiation of retraction, then 1 hour after initiating canine retraction, followed by 1 day, 7 days, 14 days and 21 days. GCF LDH levels were estimated and compared with the control site. Results The results revealed significantly higher LDH levels on the 7th, 14th and 21st day at the sites where orthodontic force had been applied. The levels also showed a significant increase from 0 hour to the 21st day. Peak levels were seen on 14th and 21st day following initiation of retraction. Conclusions: The study showed that LDH could be successfully estimated in the GCF and its increased levels could indicate active tooth movement, which could aid the clinician in monitoring active orthodontic tooth movement. PMID:21760863

  14. Evidence of lactate dehydrogenase-B allozyme effects in the teleost, Fundulus heteroclitus.

    PubMed

    DiMichele, L; Paynter, K T; Powers, D A

    1991-08-23

    The evolutionary significance of protein polymorphisms has long been debated. Exponents of the balanced theory advocate that selection operates to maintain polymorphisms, whereas the neoclassical school argues that most genetic variation is neutral. Some studies have suggested that protein polymorphisms are not neutral, but their significance has been questioned because one cannot eliminate the possibility that linked loci were responsible for the observed differences. Evidence is presented that an enzymatic phenotype can affect carbon flow through a metabolic pathway. Glucose flux differences between lactate dehydrogenase-B phenotypes of Fundulus heteroclitus were reversed by substituting the Ldh-B gene product of one homozygous genotype with that of another.

  15. Empirical evaluation of a virtual laboratory approach to teach lactate dehydrogenase enzyme kinetics.

    PubMed

    Booth, Christine; Cheluvappa, Rajkumar; Bellinson, Zack; Maguire, Danni; Zimitat, Craig; Abraham, Joyce; Eri, Rajaraman

    2016-06-01

    Personalised instruction is increasingly recognised as crucial for efficacious learning today. Our seminal work delineates and elaborates on the principles, development and implementation of a specially-designed adaptive, virtual laboratory. We strived to teach laboratory skills associated with lactate dehydrogenase (LDH) enzyme kinetics to 2nd-year biochemistry students using our adaptive learning platform. Pertinent specific aims were to:(1)design/implement a web-based lesson to teach lactate dehydrogenase(LDH) enzyme kinetics to 2nd-year biochemistry students(2)determine its efficacious in improving students' comprehension of enzyme kinetics(3)assess their perception of its usefulness/manageability(vLab versus Conventional Tutorial). Our tools were designed using HTML5 technology. We hosted the program on an adaptive e-learning platform (AeLP). Provisions were made to interactively impart informed laboratory skills associated with measuring LDH enzyme kinetics. A series of e-learning methods were created. Tutorials were generated for interactive teaching and assessment. The learning outcomes herein were on par with that from a conventional classroom tutorial. Student feedback showed that the majority of students found the vLab learning experience "valuable"; and the vLab format/interface "well-designed". However, there were a few technical issues with the 1st roll-out of the platform. Our pioneering effort resulted in productive learning with the vLab, with parity with that from a conventional tutorial. Our contingent discussion emphasises not only the cornerstone advantages, but also the shortcomings of the AeLP method utilised. We conclude with an astute analysis of possible extensions and applications of our methodology.

  16. Meta-analysis of serum lactate dehydrogenase and prognosis for osteosarcoma.

    PubMed

    Fu, Yucheng; Lan, Tao; Cai, Hongliu; Lu, Anwei; Yu, Wei

    2018-05-01

    A large number of studies have reported the relationships between serum lactate dehydrogenase (LDH) and prognosis of osteosarcoma. However, the result is still controversial and no consensus has been reached. Therefore, we performed a meta-analysis to evaluate the prognostic role of serum LDH in osteosarcoma patients. We performed the systematic computerized search for eligible articles from PubMed, Embase, and Cochrane databases until December 21, 2017. The pooled hazard ratio (HR) and 95% confidence intervals (CIs) of overall survival (OS) and event-free survival (EFS) were obtained to assess the prognostic value of serum LDH. A total of 18 studies with 2543 osteosarcoma patients were included. Overall, 15 studies assessed the elevated serum LDH level on OS and the pooled HR was 1.87 (95% CI = 1.58-2.20). Meanwhile, the pooled HR to evaluate the relationship between serum LDH and EFS in 9 studies was 1.78 (95% CI = 1.51-2.10). The same results were acquired when these studies were stratified by Enneking stage, geographic region, and sample size. No heterogeneity existed between these subgroups (P > .05). Begg's funnel plot and Egger's test (OS: P = .04; EFS: P = .34) showed that possible publication bias might exist in OS studies. Sensitivity analysis suggested the pooled HR was robust. This meta-analysis demonstrates that elevated serum LDH level is apparently associated with lower EFS rate and serum LDH could be a prognostic biomarker for osteosarcoma patients.

  17. Resting oxygen consumption varies among lactate dehydrogenase genotypes in the sow bug, Porcellio scaber

    PubMed Central

    Mitton, J. B.; Carter, P. A.; DiGiacomo, A.

    1997-01-01

    Laboratory studies of respiration in the sow bug, Porcellio scaber, reveal that respiration rates are related to genetic variation at the lactate dehydrogenase (Ldh) locus. In population samples taken from Burlington, North Carolina and Pacific Grove, California, respiration rates differed among Ldh genotypes, but not among genotypes at the other enzyme polymorphisms. In both population samples, the respiration rate of the common Ldh homozygote exceeded the respiration rate of the heterozygote by more than 50 per cent. The differences in respiration rates are consistent with previously reported viability differentials at the Ldh polymorphism.

  18. Divergent lactate dehydrogenase isoenzyme profile in cellular compartments of primate forebrain structures.

    PubMed

    Duka, Tetyana; Collins, Zachary; Anderson, Sarah M; Raghanti, Mary Ann; Ely, John J; Hof, Patrick R; Wildman, Derek E; Goodman, Morris; Grossman, Lawrence I; Sherwood, Chet C

    2017-07-01

    The compartmentalization and association of lactate dehydrogenase (LDH) with specific cellular structures (e.g., synaptosomal, sarcoplasmic or mitochondrial) may play an important role in brain energy metabolism. Our previous research revealed that LDH in the synaptosomal fraction shifts toward the aerobic isoforms (LDH-B) among the large-brained haplorhine primates compared to strepsirrhines. Here, we further analyzed the subcellular localization of LDH in primate forebrain structures using quantitative Western blotting and ELISA. We show that, in cytosolic and mitochondrial subfractions, LDH-B expression level was relatively elevated and LDH-A declined in haplorhines compared to strepsirrhines. LDH-B expression in mitochondrial fractions of the neocortex was preferentially increased, showing a particularly significant rise in the ratio of LDH-B to LDH-A in chimpanzees and humans. We also found a significant correlation between the protein levels of LDH-B in mitochondrial fractions from haplorhine neocortex and the synaptosomal LDH-B that suggests LDH isoforms shift from a predominance of A-subunits toward B-subunits as part of a system that spatially buffers dynamic energy requirements of brain cells. Our results indicate that there is differential subcellular compartmentalization of LDH isoenzymes that evolved among different primate lineages to meet the energy requirements in neocortical and striatal cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Analysis of the Mycoplasma bovis lactate dehydrogenase reveals typical enzymatic activity despite the presence of an atypical catalytic site motif.

    PubMed

    Masukagami, Yumiko; Tivendale, Kelly Anne; Browning, Glenn Francis; Sansom, Fiona Margaret

    2018-02-01

    The lactate dehydrogenase (LDH) of Mycoplasma genitalium has been predicted to also act as a malate dehydrogenase (MDH), but there has been no experimental validation of this hypothesized dual function for any mollicute. Our analysis of the metabolite profile of Mycoplasma bovis using gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) detected malate, suggesting that there may be MDH activity in M. bovis. To investigate whether the putative l-LDH enzyme of M. bovis has a dual function (MDH and LDH), we performed bioinformatic and functional biochemical analyses. Although the amino acid sequence and predicted structural analysis of M. bovisl-LDH revealed unusual residues within the catalytic site, suggesting that it may have the flexibility to possess a dual function, our biochemical studies using recombinant M. bovis -LDH did not detect any MDH activity. However, we did show that the enzyme has typical LDH activity that could be inhibited by both MDH substrates oxaloacetate (OAA) and malate, suggesting that these substrates may be able to bind to M. bovis LDH. Inhibition of the conversion of pyruvate to lactate by OAA may be one method the mycoplasma cell uses to reduce the potential for accumulation of intracellular lactate.

  20. Interaction of cytoplasmic dehydrogenases: quantitation of pathways of ethanol metabolism.

    PubMed

    Vind, C; Grunnet, N

    1983-01-01

    The interaction between xylitol, alcohol and lactate dehydrogenase has been studied in hepatocytes from rats by applying specifically tritiated substrates. A simple model, describing the metabolic fate of tritium from [2-3H] xylitol and (1R) [1-3H]ethanol is presented. The model allows calculation of the specific radioactivity of free, cytosolic NADH, based on transfer of tritium to lactate, glucose and water. From the initial labelling rate of lactate and the specific radioactivity of cytosolic NADH, we have determined the reversible flow through the lactate dehydrogenase catalyzed reaction to 1-5 mumol/min . g wet wt. The results suggest that xylitol, alcohol and lactate dehydrogenase share the same pool of NAD(H) in the cytoplasma. This finding allows estimation of the ethanol oxidation rate by the non-alcohol dehydrogenase pathways from the relative yield of tritium in water and glucose. The calculations are based on a comparison of the fate of the 1-pro-R hydrogen of ethanol and the hydrogen bound to carbon 2 of xylitol or carbon 2 of lactate under identical conditions.

  1. Role of malate dehydrogenase in facilitating lactate dehydrogenase to support the glycolysis pathway in tumors.

    PubMed

    Mansouri, Siavash; Shahriari, Ali; Kalantar, Hadi; Moini Zanjani, Taraneh; Haghi Karamallah, Mojtaba

    2017-04-01

    High aerobic glycolysis, as one of the hallmarks of cancer cells, requires nicotinamide adenine dinucleotide (NAD + ) as a vital co-factor, to guarantee the flow of glycolysis. Malate dehydrogenase (MDH), as an important enzyme in cancer metabolism, is a source of NAD + additional to lactate dehydrogenase (LDH). The current study aimed to elucidate the kinetic parameters of MDH in human breast cancer and evaluate its supportive role in the glycolysis pathway. The Michaelis-Menten constant (K m ) and maximum velocity (V max ) of MDH were determined in the crude extracts of human breast tumors and healthy tissue samples, which were obtained directly from the operating theatre. To assess the potential role of MDH in supporting glycolysis, the MDH activity was measured when the LDH activity was inhibited by different concentrations of oxamate, an inhibitor of LDH in breast cancer cell lines. The K m of cancerous MDH (C-MDH) was the same as the healthy MDH, although the V max of C-MDH was higher relative to the healthy MDH. Notably, the MDH activity was increased in the MDA-MB-231 cell line, which was treated with the LDH inhibitor (oxamate), but not in the MCF-7 cell line (P<0.05). The higher tendency of C-MDH for NAD + and malate generation in cancer cells is an effective approach for supporting glycolysis. Increasing MDH activity in the absence of LDH demonstrates the supportive role of MDH in glycolysis. Therefore, decreasing MDH activity and expression in a forward reaction may present as a valid molecular target to abolish its potential effect on tumor metabolism.

  2. White shrimp Litopenaeus vannamei recombinant lactate dehydrogenase: Biochemical and kinetic characterization.

    PubMed

    Fregoso-Peñuñuri, Ambar A; Valenzuela-Soto, Elisa M; Figueroa-Soto, Ciria G; Peregrino-Uriarte, Alma B; Ochoa-Valdez, Manuel; Leyva-Carrillo, Lilia; Yepiz-Plascencia, Gloria

    2017-09-01

    Shrimp lactate dehydrogenase (LDH) is induced in response to environmental hypoxia. Two protein subunits deduced from different transcripts of the LDH gene from the shrimp Litopenaeus vannamei (LDHvan-1 and LDHvan-2) were identified. These subunits are expressed by alternative splicing. Since both subunits are expressed in most tissues, the purification of the enzyme from the shrimp will likely produce hetero LDH containing both subunits. Therefore, the aim of this study was to overexpress, purify and characterize only one subunit as a recombinant protein, the LDHvan-2. For this, the cDNA from muscle was cloned and overexpressed in E. coli as a fusion protein containing an intein and a chitin binding protein domain (CBD). The recombinant protein was purified by chitin affinity chromatography column that retained the CBD and released solely the full and active LDH. The active protein appears to be a tetramer with molecular mass of approximately 140 kDa and can use pyruvate or lactate as substrates, but has higher specific activity with pyruvate. The enzyme is stable between pH 7.0 to 8.5, and between 20 and 50 °C with an optimal temperature of 50 °C. Two pK a of 9.3 and 6.6, and activation energy of 44.8 kJ/mol°K were found. The kinetic constants K m for NADH was 23.4 ± 1.8 μM, and for pyruvate was 203 ± 25 μM, while V max was 7.45 μmol/min/mg protein. The shrimp LDH that is mainly expressed in shrimp muscle preferentially converts pyruvate to lactate and is an important enzyme for the response to hypoxia. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Quinoline 3-sulfonamides inhibit lactate dehydrogenase A and reverse aerobic glycolysis in cancer cells

    PubMed Central

    2013-01-01

    Background Most normal cells in the presence of oxygen utilize glucose for mitochondrial oxidative phosphorylation. In contrast, many cancer cells rapidly convert glucose to lactate in the cytosol, a process termed aerobic glycolysis. This glycolytic phenotype is enabled by lactate dehydrogenase (LDH), which catalyzes the inter-conversion of pyruvate and lactate. The purpose of this study was to identify and characterize potent and selective inhibitors of LDHA. Methods High throughput screening and lead optimization were used to generate inhibitors of LDHA enzymatic activity. Effects of these inhibitors on metabolism were evaluated using cell-based lactate production, oxygen consumption, and 13C NMR spectroscopy assays. Changes in comprehensive metabolic profile, cell proliferation, and apoptosis were assessed upon compound treatment. Results 3-((3-carbamoyl-7-(3,5-dimethylisoxazol-4-yl)-6-methoxyquinolin-4-yl) amino) benzoic acid was identified as an NADH-competitive LDHA inhibitor. Lead optimization yielded molecules with LDHA inhibitory potencies as low as 2 nM and 10 to 80-fold selectivity over LDHB. Molecules in this family rapidly and profoundly inhibited lactate production rates in multiple cancer cell lines including hepatocellular and breast carcinomas. Consistent with selective inhibition of LDHA, the most sensitive breast cancer cell lines to lactate inhibition in hypoxic conditions were cells with low expression of LDHB. Our inhibitors increased rates of oxygen consumption in hepatocellular carcinoma cells at doses up to 3 microM, while higher concentrations directly inhibited mitochondrial function. Analysis of more than 500 metabolites upon LDHA inhibition in Snu398 cells revealed that intracellular concentrations of glycolysis and citric acid cycle intermediates were increased, consistent with enhanced Krebs cycle activity and blockage of cytosolic glycolysis. Treatment with these compounds also potentiated PKM2 activity and promoted apoptosis in Snu

  4. Epitopes of human testis-specific lactate dehydrogenase deduced from a cDNA sequence

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Millan, J.L.; Driscoll, C.E.; LeVan, K.M.

    The sequence and structure of human testis-specific L-lactate dehydrogenase (LDHC/sub 4/, LDHX; (L)-lactate:NAD/sup +/ oxidoreductase, EC 1.1.1.27) has been derived from analysis of a complementary DNA (cDNA) clone comprising the complete protein coding region of the enzyme. From the deduced amino acid sequence, human LDHC/sub 4/ is as different from rodent LDHC/sub 4/ (73% homology) as it is from human LDHA/sub 4/ (76% homology) and porcine LDHB/sub 4/ (68% homology). Subunit homologies are consistent with the conclusion that the LDHC gene arose by at least two independent duplication events. Furthermore, the lower degree of homology between mouse and human LDHC/submore » 4/ and the appearance of this isozyme late in evolution suggests a higher rate of mutation in the mammalian LDHC genes than in the LDHA and -B genes. Comparison of exposed amino acid residues of discrete anti-genic determinants of mouse and human LDHC/sub 4/ reveals significant differences. Knowledge of the human LDHC/sub 4/ sequence will help design human-specific peptides useful in the development of a contraceptive vaccine.« less

  5. Lactate dehydrogenase-A is indispensable for vascular smooth muscle cell proliferation and migration.

    PubMed

    Kim, Ji-Hyun; Bae, Kwi-Hyun; Byun, Jun-Kyu; Lee, Sungwoo; Kim, Jung-Guk; Lee, In Kyu; Jung, Gwon-Soo; Lee, You Mie; Park, Keun-Gyu

    2017-10-07

    The proliferation and migration of vascular smooth muscle cells (VSMCs) have been implicated in the pathogenesis of atherosclerosis. Increased aerobic glycolysis is a key feature of cellular phenotypes including cancer and immune cells. However, the role of aerobic glycolysis in the atherogenic phenotype of VSMCs remains largely unknown. Here, we investigated the role of lactate dehydrogenase-A (LDHA), which is a key enzyme for glycolysis, in the proliferation and migration of VSMCs. Activation of primary rat VSMCs with fetal bovine serum (FBS) or platelet-derived growth factor (PDGF) increased their proliferation and migration, glycolytic activity, and expression of LDHA. Wound healing and transwell migration assays demonstrated that small interfering RNA-mediated knockdown of LDHA and pharmacological inhibition of LDHA by oxamate both effectively inhibited VSMC proliferation and migration. Inhibition of LDHA activity by oxamate reduced PDGF-stimulated glucose uptake, lactate production, and ATP production. Taken together, this study shows that enhanced glycolysis in PDGF- or FBS-stimulated VSMCs plays an important role in their proliferation and migration and suggests that LDHA is a potential therapeutic target to prevent vessel lumen constriction during the course of atherosclerosis and restenosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Cloning of D-lactate dehydrogenase genes of Lactobacillus delbrueckii subsp. bulgaricus and their roles in D-lactic acid production.

    PubMed

    Huang, Yanna; You, Chunping; Liu, Zhenmin

    2017-07-01

    Lactobacillus delbrueckii subsp. bulgaricus is a heterogenous lactic acid bacterium that converts pyruvate mainly to D-lactic acid using D-lactate dehydrogenases (D-LDHs), whose functional properties remain poorly characterized. Here, the D-LDHs genes (ldb0101, ldb0813, ldb1010, ldb1147 and ldb2021) were cloned and overexpressed in Escherichia coli JM109 from an inducible pUC18 vector, respectively, and the resulting strains were compared in terms of D-lactic acid production. The strain expressing ldb0101 and ldb1010 gene individually produced more D-lactate than other three strains. Further study revealed that Ldb0101 activity was down-regulated by the oxygen and, therefore, achieved a highest titer of D-lactate (1.94 g/L) under anaerobic condition, and introduction of ldb1010 gene enhanced D-lactate formation (0.94 and 0.85 g/L, respectively) both in aerobic and anaerobic conditions due to a relatively stable q d-lactate . Our results suggested that the enzyme Ldb0101 and Ldb1010 played a role of more importance in D-lactate formation. To the best of our knowledge, we demonstrate for the first time the roles of different D-LDH homologs from L. bulgaricus in D-lactic acid production.

  7. Cloning and polymorphisms of yak lactate dehydrogenase B gene.

    PubMed

    Wang, Guosheng; Zhao, Xingbo; Zhong, Juming; Cao, Meng; He, Qinghua; Liu, Zhengxin; Lin, Yaqiu; Xu, Yaou; Zheng, Yucai

    2013-06-05

    The main objective of this work was to study the unique polymorphisms of the lactate dehydrogenase-1 (LDH1) gene in yak (Bos grunniens). Native polyacrylamide gel electrophoresis revealed three phenotypes of LDH1 (a tetramer of H subunit) in yak heart and longissimus muscle extracts. The corresponding gene, ldhb, encoding H subunits of three LDH1 phenotypes was obtained by RT-PCR. A total of six nucleotide differences were detected in yak ldhb compared with that of cattle, of which five mutations cause amino acid substitutions. Sequence analysis shows that the G896A and C689A, mutations of ldhb gene, result in alterations of differently charged amino acids, and create the three phenotypes (F, M, and S) of yak LDH1. Molecular modeling of the H subunit of LDH indicates that the substituted amino acids are not located within NAD+ or substrate binding sites. PCR-RFLP examination of G896A mutation demonstrated that most LDH1-F samples are actually heterozygote at this site. These results help to elucidate the molecular basis and genetic characteristic of the three unique LDH1 phenotypes in yak.

  8. Cloning and Polymorphisms of Yak Lactate Dehydrogenase b Gene

    PubMed Central

    Wang, Guosheng; Zhao, Xingbo; Zhong, Juming; Cao, Meng; He, Qinghua; Liu, Zhengxin; Lin, Yaqiu; Xu, Yaou; Zheng, Yucai

    2013-01-01

    The main objective of this work was to study the unique polymorphisms of the lactate dehydrogenase-1 (LDH1) gene in yak (Bos grunniens). Native polyacrylamide gel electrophoresis revealed three phenotypes of LDH1 (a tetramer of H subunit) in yak heart and longissimus muscle extracts. The corresponding gene, ldhb, encoding H subunits of three LDH1 phenotypes was obtained by RT-PCR. A total of six nucleotide differences were detected in yak ldhb compared with that of cattle, of which five mutations cause amino acid substitutions. Sequence analysis shows that the G896A and C689A, mutations of ldhb gene, result in alterations of differently charged amino acids, and create the three phenotypes (F, M, and S) of yak LDH1. Molecular modeling of the H subunit of LDH indicates that the substituted amino acids are not located within NAD+ or substrate binding sites. PCR-RFLP examination of G896A mutation demonstrated that most LDH1-F samples are actually heterozygote at this site. These results help to elucidate the molecular basis and genetic characteristic of the three unique LDH1 phenotypes in yak. PMID:23739677

  9. Towards development of aptamers that specifically bind to lactate dehydrogenase of Plasmodium falciparum through epitopic targeting.

    PubMed

    Frith, Kelly-Anne; Fogel, Ronen; Goldring, J P Dean; Krause, Robert G E; Khati, Makobetsa; Hoppe, Heinrich; Cromhout, Mary E; Jiwaji, Meesbah; Limson, Janice L

    2018-05-03

    Early detection is crucial for the effective treatment of malaria, particularly in those cases infected with Plasmodium falciparum. There is a need for diagnostic devices with the capacity to distinguish P. falciparum from other strains of malaria. Here, aptamers generated against targeted species-specific epitopes of P. falciparum lactate dehydrogenase (rPfLDH) are described. Two classes of aptamers bearing high binding affinity and specificity for recombinant P. falciparum lactate dehydrogenase (rPfLDH) and P. falciparum-specific lactate dehydrogenase epitopic oligopeptide (LDHp) were separately generated. Structurally-relevant moieties with particular consensus sequences (GGTAG and GGCG) were found in aptamers reported here and previously published, confirming their importance in recognition of the target, while novel moieties particular to this work (ATTAT and poly-A stretches) were identified. Aptamers with diagnostically-supportive functions were synthesized, prime examples of which are the aptamers designated as LDHp 1, LDHp 11 and rLDH 4 and rLDH 15 in work presented herein. Of the sampled aptamers raised against the recombinant protein, rLDH 4 showed the highest binding to the target rPfLDH in the ELONA assay, with both rLDH 4 and rLDH 15 indicating an ability to discriminate between rPfLDH and rPvLDH. LDHp 11 was generated against a peptide selected as a unique P. falciparum LDH peptide. The aptamer, LDHp 11, like antibodies against the same peptide, only detected rPfLDH and discriminated between rPfLDH and rPvLDH. This was supported by affinity binding experiments where only aptamers generated against a unique species-specific epitope showed an ability to preferentially bind to rPfLDH relative to rPvLDH rather than those generated against the whole recombinant protein. In addition, rLDH 4 and LDHp 11 demonstrated in situ binding to P. falciparum cells during confocal microscopy. The utilization and application of LDHp 11, an aptamer generated against a

  10. Reference values of blood parameters in beef cattle of different ages and stages of lactation.

    PubMed Central

    Doornenbal, H; Tong, A K; Murray, N L

    1988-01-01

    Reference (normal) values for 12 blood serum components were determined for 48 Shorthorn cows (2-10 years old) and their 48 calves, 357 crossbred cows (12-14 years old), 36 feedlot bulls and 36 feedlot steers. In addition, hemoglobin, hematocrit, triiodothyronine, thyroxine and cortisol levels were determined for the crossbred cows, and feedlot bulls and steers. Reference values were tabulated according to sex, age and stage of lactation. Serum concentrations of urea, total protein and bilirubin, and serum activity of aspartate aminotransferase and lactate dehydrogenase increased with age (P less than 0.05), while calcium, phosphorus and alkaline phosphatase decreased with age (P less than 0.05) from birth to the age of ten years. The Shorthorn cows had the highest levels of glucose at parturition (P less than 0.05) with decreasing levels during lactation. Creatinine concentration decreased during lactation and increased during postweaning. Both lactate dehydrogenase and aspartate aminotransferase levels increased (P less than 0.05) during lactation. Urea and uric acid were present at higher concentrations in lactating than nonlactating cows (P less than 0.05). The values reported, based on a wide age range and large number of cattle, could serve as clinical guides and a basis for further research. PMID:3349406

  11. Supplementation of medium with diammonium hydrogen phosphate enhanced the D-lactate dehydrogenase levels leading to increased D-lactic acid productivity.

    PubMed

    Singhvi, Mamata; Jadhav, Akanksha; Gokhale, Digambar

    2013-10-01

    The production of D-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5 g/l peptone and 1 g/l (NH4)2HPO4 enhanced D-lactic acid production by 32%, as compared to that obtained from non supplemented media, with a productivity of 3.0 g/l/h. Lactate dehydrogenase (LDH) expression profile in these different media was studied which resulted in appearance of additional LDH isoform produced by cells when they were grown in HSYE supplemented with (NH4)2HPO4. The additional LDH appears to be L-LDH contributing to production of L-lactic acid in the fermented broth. This is totally new information in the lactic acid fermentation and could be very useful to industries engaged in D-lactic acid production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Misconceptions regarding basic thermodynamics and enzyme kinetics have led to erroneous conclusions regarding the metabolic importance of lactate dehydrogenase isoenzyme expression.

    PubMed

    Bak, Lasse K; Schousboe, Arne

    2017-11-01

    Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate involving the coenzyme NAD + . Part of the foundation for the proposed shuttling of lactate from astrocytes to neurons during brain activation is the differential distribution of LDH isoenzymes between the two cell types. In this short review, we outline the basic kinetic properties of the LDH isoenzymes expressed in neurons and astrocytes, and argue that the distribution of LDH isoenzymes does not in any way govern directional flow of lactate between the two cellular compartments. The two main points are as follows. First, in line with the general concept of chemical catalysis, enzymes do not influence the thermodynamic equilibrium of a chemical reaction but merely the speed at which equilibrium is obtained. Thus, differential distribution of LDH isoenzymes with different kinetic parameters does not predict which cells are producing and which are consuming lactate. Second, the thermodynamic equilibrium of the reaction is toward the reduced substrate (i.e., lactate), which is reflected in the concentrations measured in brain tissue, suggesting that the reaction is at near-equilibrium at steady state. To conclude, the cellular distribution of LDH isoenzymes is of little if any consequence in determining any directional flow of lactate between neurons and astrocytes. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  13. Molecular Characterization of Two Lactate Dehydrogenase Genes with a Novel Structural Organization on the Genome of Lactobacillus sp. Strain MONT4

    PubMed Central

    Weekes, Jennifer; Yüksel, Gülhan Ü.

    2004-01-01

    Two lactate dehydrogenase (ldh) genes from Lactobacillus sp. strain MONT4 were cloned by complementation in Escherichia coli DC1368 (ldh pfl) and were sequenced. The sequence analysis revealed a novel genomic organization of the ldh genes. Subcloning of the individual ldh genes and their Northern blot analyses indicated that the genes are monocistronic. PMID:15466577

  14. From Gene to Structure: "Lactobacillus Bulgaricus" D-Lactate Dehydrogenase from Yogurt as an Integrated Curriculum Model for Undergraduate Molecular Biology and Biochemistry Laboratory Courses

    ERIC Educational Resources Information Center

    Lawton, Jeffrey A.; Prescott, Noelle A.; Lawton, Ping X.

    2018-01-01

    We have developed an integrated, project-oriented curriculum for undergraduate molecular biology and biochemistry laboratory courses spanning two semesters that is organized around the "ldhA" gene from the yogurt-fermenting bacterium "Lactobacillus bulgaricus," which encodes the enzyme d-lactate dehydrogenase. The molecular…

  15. Stringency of substrate specificity of Escherichia coli malate dehydrogenase.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boernke, W. E.; Millard, C. S.; Stevens, P. W.

    1995-09-10

    Malate dehydrogenase and lactate dehydrogenase are members of the structurally and functionally homologous family of 2-ketoacid dehydrogenases. Both enzymes display high specificity for their respective keto substrates, oxaloacetate and pyruvate. Closer analysis of their specificity, however, reveals that the specificity of malate dehydrogenase is much stricter and less malleable than that of lactate dehydrogenase. Site-specific mutagenesis of the two enzymes in an attempt to reverse their specificity has met with contrary results. Conversion of a specific active-site glutamine to arginine in lactate dehydrogenase from Bacillus stearothermophilus generated an enzyme that displayed activity toward oxaloacetate equal to that of the nativemore » enzyme toward pyruvate (H. M. Wilks et al. (1988) Science 242, 1541-1544). We have constructed a series of mutants in the mobile, active site loop of the Escherichia coli malate dehydrogenase that incorporate the complementary change, conversion of arginine 81 to glutamine, to evaluate the role of charge distribution and conformational flexibility within this loop in defining the substrate specificity of these enzymes. Mutants incorporating the change R81Q all had reversed specificity, displaying much higher activity toward pyruvate than to the natural substrate, oxaloacetate. In contrast to the mutated lactate dehydrogenase, these reversed-specificity mutants were much less active than the native enzyme. Secondary mutations within the loop of the E. coli enzyme (A80N, A80P, A80P/M85E/D86T) had either no or only moderately beneficial effects on the activity of the mutant enzyme toward pyruvate. The mutation A80P, which can be expected to reduce the overall flexibility of the loop, modestly improved activity toward pyruvate. The possible physiological relevance of the stringent specificity of malate dehydrogenase was investigated. In normal strains of E. coli, fermentative metabolism was not affected by expression of the

  16. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants.

    PubMed

    Morales-Alamo, David; Guerra, Borja; Santana, Alfredo; Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Dorado, Cecilia; Calbet, José A L

    2018-01-01

    Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH) activation and reactive nitrogen and oxygen species (RNOS) in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test) on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (P I O 2 = 75 mmHg) or room air (P I O 2 = 143 mmHg). Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO 2 . Immediately after the sprints, Ser 293 - and Ser 300 -PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively). However, 30 min into recovery Ser 293 -PDH-E1α phosphorylation reached pre-exercise values while Ser 300 -PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser 293 -PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser 293 and Ser 300 -PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo ( r = 0.74, P < 0.001; n = 18), but not after antioxidants ingestion ( r = 0.35, P = 0.15). In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser 293 re-phosphorylates at a faster rate than Ser 300 -PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms.

  17. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants

    PubMed Central

    Morales-Alamo, David; Guerra, Borja; Santana, Alfredo; Martin-Rincon, Marcos; Gelabert-Rebato, Miriam; Dorado, Cecilia; Calbet, José A. L.

    2018-01-01

    Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH) activation and reactive nitrogen and oxygen species (RNOS) in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test) on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (PIO2 = 75 mmHg) or room air (PIO2 = 143 mmHg). Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO2. Immediately after the sprints, Ser293- and Ser300-PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively). However, 30 min into recovery Ser293-PDH-E1α phosphorylation reached pre-exercise values while Ser300-PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser293-PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser293 and Ser300-PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo (r = 0.74, P < 0.001; n = 18), but not after antioxidants ingestion (r = 0.35, P = 0.15). In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser293 re-phosphorylates at a faster rate than Ser300-PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms. PMID:29615918

  18. Importance of measuring lactate levels in children with sepsis.

    PubMed

    Anil, Nisha

    2017-10-10

    Sepsis is a major public health problem as well as one of the leading causes of preventable death in children because of failure to recognise the early signs and symptoms and to resuscitate rapidly. Blood lactate levels are used to assess the severity of sepsis and the effectiveness of resuscitation. Lactate levels are easily obtainable and should be checked in all patients admitted with suspected sepsis within six hours of presentation. The test should be repeated four and eight-hours post-diagnosis of sepsis. For the diagnosis of sepsis, patients' clinical symptoms, along with the combined analysis of partial pressure of oxygen, carbon dioxide and lactate levels, should be used. A multitude of factors can cause elevated lactate levels and so clinicians should use elevated levels cautiously by considering all other aetiologies. This article, which focuses on practice in Australia but makes reference to the UK, discusses the importance of measuring lactate levels in sepsis, the pathophysiology of lactate production, causes of elevated lactate levels, lactate measurement, nursing management of patients with elevated lactate levels, limitations of using lactate as a biomarker for diagnosing sepsis and implications for practice. ©2012 RCN Publishing Company Ltd. All rights reserved. Not to be copied, transmitted or recorded in any way, in whole or part, without prior permission of the publishers.

  19. Stilbene Glucoside, a Putative Sleep Promoting Constituent from Polygonum multiflorum Affects Sleep Homeostasis by Affecting the Activities of Lactate Dehydrogenase and Salivary Alpha Amylase.

    PubMed

    Wei, Qian; Ta, Guang; He, Wenjing; Wang, Wei; Wu, Qiucheng

    2017-01-01

    Chinese herbal medicine (CHM) has been used for treating insomnia for centuries. The most used CHM for insomnia was Polygonum multiflorum. However, the molecular mechanism for CHM preventing insomnia is unknown. Stilbene glucoside (THSG), an important active component of P. multiflorum, may play an important role for treating insomnia. To test the hypothesis, Kunming mice were treated with different dosages of THSG. To examine the sleep duration, a computer-controlled sleep-wake detection system was implemented. Electroencephalogram (EEG) and electromyogram (EMG) electrodes were implanted to determine sleep-wake state. RT-PCR and Western blot was used to measure the levels of lactate dehydrogenase (LDH) and saliva alpha amylase. Spearman's rank correlation coefficient was used to identify the strength of correlation between the variables. The results showed that THSG significantly prolonged the sleep time of the mice (p<0.01). THSG changed sleep profile by reducing wake and rapid eye movement (REM) period, and increasing non-REM period. RT-PCR and Western blot analysis showed that THSG could down-regulate the levels of LDH and saliva alpha amylase (p<0.05). The level of lactate and glucose was positively related with the activity of LDH and saliva alpha amylase (p<0.05), respectively. On the other hand, the activities of LDH and amylase were negatively associated with sleep duration (p<0.05). The levels of lactate and glucose affect sleep homeostasis. Thus, THSG may prevent insomnia by regulating sleep duration via LDH and salivary alpha amylase.

  20. Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans

    PubMed Central

    Wang, Limin; Cai, Yumeng; Zhu, Lingfeng; Guo, Honglian

    2014-01-01

    Bacillus coagulans 2-6 is an excellent producer of optically pure l-lactic acid. However, little is known about the mechanism of synthesis of the highly optically pure l-lactic acid produced by this strain. Three enzymes responsible for lactic acid production—NAD-dependent l-lactate dehydrogenase (l-nLDH; encoded by ldhL), NAD-dependent d-lactate dehydrogenase (d-nLDH; encoded by ldhD), and glycolate oxidase (GOX)—were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid. Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (a d-lactic acid producer) and Lactobacillus plantarum subsp. plantarum DSM 20174 (a dl-lactic acid producer) were also examined in this study as comparative strains, in addition to B. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterized in vivo and in vitro, and the levels of transcription of the ldhL, ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities of l-nLDH and d-nLDH were different in l-, d-, and dl-lactic acid producers. Only l-nLDH activity was detected in B. coagulans 2-6 under native conditions, and the level of transcription of ldhL in B. coagulans 2-6 was much higher than that of ldhD or the GOX gene at all growth phases. However, for the two Lactobacillus strains used in this study, ldhD transcription levels were higher than those of ldhL. The high catalytic efficiency of l-nLDH toward pyruvate and the high transcription ratios of ldhL to ldhD and ldhL to the GOX gene provide the key explanations for the high optical purity of l-lactic acid produced by B. coagulans 2-6. PMID:25217009

  1. Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans.

    PubMed

    Wang, Limin; Cai, Yumeng; Zhu, Lingfeng; Guo, Honglian; Yu, Bo

    2014-12-01

    Bacillus coagulans 2-6 is an excellent producer of optically pure l-lactic acid. However, little is known about the mechanism of synthesis of the highly optically pure l-lactic acid produced by this strain. Three enzymes responsible for lactic acid production-NAD-dependent l-lactate dehydrogenase (l-nLDH; encoded by ldhL), NAD-dependent d-lactate dehydrogenase (d-nLDH; encoded by ldhD), and glycolate oxidase (GOX)-were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid. Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (a d-lactic acid producer) and Lactobacillus plantarum subsp. plantarum DSM 20174 (a dl-lactic acid producer) were also examined in this study as comparative strains, in addition to B. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterized in vivo and in vitro, and the levels of transcription of the ldhL, ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities of l-nLDH and d-nLDH were different in l-, d-, and dl-lactic acid producers. Only l-nLDH activity was detected in B. coagulans 2-6 under native conditions, and the level of transcription of ldhL in B. coagulans 2-6 was much higher than that of ldhD or the GOX gene at all growth phases. However, for the two Lactobacillus strains used in this study, ldhD transcription levels were higher than those of ldhL. The high catalytic efficiency of l-nLDH toward pyruvate and the high transcription ratios of ldhL to ldhD and ldhL to the GOX gene provide the key explanations for the high optical purity of l-lactic acid produced by B. coagulans 2-6. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Microcomputer Assisted Interpretative Reporting of Sequential Creatine Kinase (CK) and Lactate Dehydrogenase (LDH) Isoenzyme Determination

    PubMed Central

    Talamo, Thomas S.; Losos, Frank J.; Mercer, Donald W.

    1984-01-01

    We have developed a microcomputer based system for interpretative reporting of creatine kinase (CK) and lactate dehydrogenase (LDH) isoenzyme studies. Patient demographic data and test results (total CK, CK-MB, LD-1, and LD-2) are entered manually through the keyboard. The test results are compared with normal range values and an interpretative report is generated. This report consists of all pertinent demographic information with a graphic display of up to 12 previous CK and LDH isoenzyme determinations. Diagnostic interpretative statements are printed beneath the graphic display following analysis of previously entered test results. The combination of graphic data display and interpretations based on analysis of up to 12 previous specimens provides useful and accurate information to the cardiologist.

  3. Free energy landscape of the Michaelis complex of lactate dehydrogenase: A network analysis of atomistic simulations

    NASA Astrophysics Data System (ADS)

    Pan, Xiaoliang; Schwartz, Steven

    2015-03-01

    It has long been recognized that the structure of a protein is a hierarchy of conformations interconverting on multiple time scales. However, the conformational heterogeneity is rarely considered in the context of enzymatic catalysis in which the reactant is usually represented by a single conformation of the enzyme/substrate complex. Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate with concomitant interconversion of two forms of the cofactor nicotinamide adenine dinucleotide (NADH and NAD+). Recent experimental results suggest that multiple substates exist within the Michaelis complex of LDH, and they are catalytic competent at different reaction rates. In this study, millisecond-scale all-atom molecular dynamics simulations were performed on LDH to explore the free energy landscape of the Michaelis complex, and network analysis was used to characterize the distribution of the conformations. Our results provide a detailed view of the kinetic network the Michaelis complex and the structures of the substates at atomistic scale. It also shed some light on understanding the complete picture of the catalytic mechanism of LDH.

  4. Free energy surface of the Michaelis complex of lactate dehydrogenase: a network analysis of microsecond simulations.

    PubMed

    Pan, Xiaoliang; Schwartz, Steven D

    2015-04-30

    It has long been recognized that the structure of a protein creates a hierarchy of conformations interconverting on multiple time scales. The conformational heterogeneity of the Michaelis complex is of particular interest in the context of enzymatic catalysis in which the reactant is usually represented by a single conformation of the enzyme/substrate complex. Lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and lactate with concomitant interconversion of two forms of the cofactor nicotinamide adenine dinucleotide (NADH and NAD(+)). Recent experimental results suggest that multiple substates exist within the Michaelis complex of LDH, and they show a strong variance in their propensity toward the on-enzyme chemical step. In this study, microsecond-scale all-atom molecular dynamics simulations were performed on LDH to explore the free energy landscape of the Michaelis complex, and network analysis was used to characterize the distribution of the conformations. Our results provide a detailed view of the kinetic network of the Michaelis complex and the structures of the substates at atomistic scales. They also shed light on the complete picture of the catalytic mechanism of LDH.

  5. Kinetic characterization of recombinant Bacillus coagulans FDP-activated l-lactate dehydrogenase expressed in Escherichia coli and its substrate specificity.

    PubMed

    Jiang, Ting; Xu, Yanbing; Sun, Xiucheng; Zheng, Zhaojuan; Ouyang, Jia

    2014-03-01

    Bacillus coagulans is a homofermentative, acid-tolerant and thermophilic sporogenic lactic acid bacterium, which is capable of producing high yields of optically pure lactic acid. The l-(+)-lactate dehydrogenase (l-LDH) from B. coagulans is considered as an ideal biocatalyst for industrial production. In this study, the gene ldhL encoding a thermostable l-LDH was amplified from B. coagulans NL01 genomic DNA and successfully expressed in Escherichia coli BL21 (DE3). The recombinant enzyme was partially purified and its enzymatic properties were characterized. Sequence analysis demonstrated that the l-LDH was a fructose 1,6-diphosphate-activated NAD-dependent lactate dehydrogenase (l-nLDH). Its molecular weight was approximately 34-36kDa. The Km and Vmax values of the purified l-nLDH for pyruvate were 1.91±0.28mM and 2613.57±6.43μmol(minmg)(-1), respectively. The biochemical properties of l-nLDH showed that the specific activity were up to 2323.29U/mg with optimum temperature of 55°C and pH of 6.5 in the pyruvate reduction and 351.01U/mg with temperature of 55°C and pH of 11.5 in the lactate oxidation. The enzyme also showed some activity in the absence of FDP, with a pH optimum of 4.0. Compared to other lactic acid bacterial l-nLDHs, the enzyme was found to be relatively stable at 50°C. Ca(2+), Ba(2+), Mg(2+) and Mn(2+) ions had activated effects on the enzyme activity, and the enzyme was greatly inhibited by Ni(2+) ion. Besides these, l-nLDH showed the higher specificity towards pyruvate esters, such as methyl pyruvate and ethyl pyruvate. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Contributory roles of two l-lactate dehydrogenases for l-lactic acid production in thermotolerant Bacillus coagulans.

    PubMed

    Sun, Lifan; Zhang, Caili; Lyu, Pengcheng; Wang, Yanping; Wang, Limin; Yu, Bo

    2016-11-25

    Thermotolerant Bacillus coagulans is considered to be a more promising producer for bio-chemicals, due to its capacity to withstand harsh conditions. Two L-lactate dehydrogenase (LDH) encoding genes (ldhL1 and ldhL2) and one D-LDH encoding gene (ldhD) were annotated from the B. coagulans DSM1 genome. Transcriptional analysis revealed that the expression of ldhL2 was undetectable while the ldhL1 transcription level was much higher than that of ldhD at all growth phases. Deletion of the ldhL2 gene revealed no difference in fermentation profile compared to the wild-type strain, while ldhL1 single deletion or ldhL1ldhL2 double deletion completely blocked L-lactic acid production. Complementation of ldhL1 in the above knockout strains restored fermentation profiles to those observed in the wild-type strain. This study demonstrates ldhL1 is crucial for L-lactic acid production and NADH balance in B. coagulans DSM1 and lays the fundamental for engineering the thermotolerant B. coagulans strain as a platform chemicals producer.

  7. [Experience in using the latent activity of leukocytic lactate dehydrogenase isoenzymes for the integral estimate of the level of free radical oxidation in patients with neurotic disorders].

    PubMed

    Kuskov, M V

    2006-06-01

    The aggregatory properties of a leukocytic homogenate were studied by analyzing the activity of its lactate dehydrogenase (LDH) isoenzymes from patients with neurotic disorders on admission and during treatment. As a parameter reflecting the aggregatory properties of the leukocytic homogenate, the latent activity of LDH isoenzymes was studied. On admission, the patients were shown to have a lower latent activity, which restored during treatment to the control values, than in the control group. There was also a synchronous pattern of a change in the osmotic stability of red blood cells with the latent activity of leukocytic LDH isoenzymes in the treated patients. It is obvious that latent activity values reflect the level of free radical oxidation in the body. For detailed testing of the aggregatory properties of a cellular lysate, the trends in the latent activity of LDH isoenzymes were examined, which failed to reveal an unambiguous recovery of the observed parameters during therapy. Based on the findings, the author discusses whether this method can be used to analyze the time course of changes in a psychopathological process and to predict its outcome.

  8. Correlation of low levels of nitrite and high levels of fetal hemoglobin in patients with sickle cell disease at baseline

    PubMed Central

    Elias, Darcielle Bruna Dias; Rocha, Lilianne Brito da Silva; Cavalcante, Maritza Barbosa; Pedrosa, Alano Martins; Justino, Izabel Cristina Bandeira; Gonçalves, Romélia Pinheiro

    2012-01-01

    Background Sickle cell disease is a hemoglobinopathy characterized by hemolytic anemia, increased susceptibility to infections and recurrent vaso-occlusive crises that reduces the quality of life of sufferers. Objective To evaluate the correlation of the levels of lactate dehydrogenase, malonaldehyde and nitrite to fetal hemoglobin in patients with sickle cell disease not under treatment with hydroxyurea in outpatients at a university hospital in Fortaleza, Ceará, Brazil. Methods Forty-four patients diagnosed with sickle cell disease were enrolled at baseline. Diagnosis was confirmed by evaluating the beta globin gene using polymerase chain reaction-restriction fragment length polymorphism. The concentration of fetal hemoglobin was obtained by high-performance liquid chromatography. Serum levels of nitrite, malonaldehyde and lactate dehydrogenase were measured by biochemical methods. Results Significantly higher levels of lactate dehydrogenase, nitrite and malonaldehyde were observed in patients with sickle cell disease compared to a control group. The study of the correlation between fetal hemoglobin levels and these variables showed a negative correlation with nitrite levels. No correlation was found between fetal hemoglobin and malonaldehyde or lactate dehydrogenase. When the study population was stratified according to fetal hemoglobin levels, a decrease in the levels of nitrite was observed with higher levels of fetal hemoglobin (p-value = 0.0415). Conclusion The results show that, similar to fetal hemoglobin levels, the concentration of nitrite can predict the clinical course of the disease, but should not be used alone as a modulator of prognosis in patients with sickle cell disease. PMID:23049438

  9. Vitamin D levels among pregnant and lactating women.

    PubMed

    Sharif, Saima; Farasat, Tasnim; Shoaib, Hamna; Saqib, Muhammad; Fazal, Sabiha

    2013-12-01

    To assess the serum level of vitamin D in pregnant and lactating women. Case-control study. Gynaecological Unit 1 of Jinnah Hospital, Lahore, from December 2010 to May 2011. A total of 100 women comprised of three groups: pregnant (n = 40), lactating (n = 40) and control (n = 20) groups. The information regarding age, educational level, socioeconomic status, exposure to sunlight and dietary vitamin D intake were collected through self-structured questionnaire. Serum concentration of vitamin D was measured by ELISA and serum calcium and phosphate levels were measured by chemistry analyzer. Statistical analysis was done using SPSS (version 13). The values were considered significant at 0.05 level of significance. The mean serum vitamin D level in the pregnant and lactating mothers was 26.5 ± 17.1 nmol/L and 21.4 ± 16.3 nmol/L respectively and in control group was 33.8 ± 21.1 nmol/L. The mean calcium level in the pregnant, lactating and control group was 10.3 ± 1.2 mg/dL, 9.7 ± 1.3 mg/dL and 9.7 ± 1.3 mg/dL respectively. The mean phosphate in pregnant was 3.2 ± 0.76 mg/dl, in lactating was 3.3 ± 0.76 mg/dl and in control was 3.5 ± 0.92 mg/dl. Significant difference (p = 0.041 and p = 0.037 respectively) in the serum levels of vitamin D and calcium was observed among the pregnant and lactating women as compared to control group. Low serum vitamin D concentration was observed in lactating women and pregnant women as compared to control group.

  10. Molecular cloing and bioinformatics analysis of lactate dehydrogenase from Taenia multiceps.

    PubMed

    Guo, Cheng; Wang, Yu; Huang, Xing; Wang, Ning; Yan, Ming; He, Ran; Gu, Xiaobin; Xie, Yue; Lai, Weimin; Jing, Bo; Peng, Xuerong; Yang, Guangyou

    2017-10-01

    Coenurus cerebralis, the larval stage (metacestode or coenurus) of Taenia multiceps, parasitizes sheep, goats, and other ruminants and causes coenurosis. In this study, we isolated and characterized complementary DNAs that encode lactate dehydrogenase A (Tm-LDHA) and B (Tm-LDHB) from the transcriptome of T. multiceps and expressed recombinant Tm-LDHB (rTm-LDHB) in Escherichia coli. Bioinformatic analysis showed that both Tm-LDH genes (LDHA and LDHB) contain a 996-bp open reading frame and encode a protein of 331 amino acids. After determination of the immunogenicity of the recombinant Tm-LDHB, an indirect enzyme-linked immunosorbent assay (ELISA) was developed for preliminary evaluation of the serodiagnostic potential of rTm-LDHB in goats. However, the rTm-LDHB-based indirect ELISA developed here exhibited specificity of only 71.42% (10/14) and sensitivity of 1:3200 in detection of goats infected with T. multiceps in the field. This study is the first to describe LDHA and LDHB of T. multiceps; meanwhile, our results indicate that rTm-LDHB is not a specific antigen candidate for immunodiagnosis of T. multiceps infection in goats.

  11. Computational analyses of mammalian lactate dehydrogenases: human, mouse, opossum and platypus LDHs.

    PubMed

    Holmes, Roger S; Goldberg, Erwin

    2009-10-01

    Computational methods were used to predict the amino acid sequences and gene locations for mammalian lactate dehydrogenase (LDH) genes and proteins using genome sequence databanks. Human LDHA, LDHC and LDH6A genes were located in tandem on chromosome 11, while LDH6B and LDH6C genes were on chromosomes 15 and 12, respectively. Opossum LDHC and LDH6B genes were located in tandem with the opossum LDHA gene on chromosome 5 and contained 7 (LDHA and LDHC) or 8 (LDH6B) exons. An amino acid sequence prediction for the opossum LDH6B subunit gave an extended N-terminal sequence, similar to the human and mouse LDH6B sequences, which may support the export of this enzyme into mitochondria. The platypus genome contained at least 3 LDH genes encoding LDHA, LDHB and LDH6B subunits. Phylogenetic studies and sequence analyses indicated that LDHA, LDHB and LDH6B genes are present in all mammalian genomes examined, including a monotreme species (platypus), whereas the LDHC gene may have arisen more recently in marsupial mammals.

  12. Computational analyses of mammalian lactate dehydrogenases: human, mouse, opossum and platypus LDHs

    PubMed Central

    Holmes, Roger S; Goldberg, Erwin

    2009-01-01

    Computational methods were used to predict the amino acid sequences and gene locations for mammalian lactate dehydrogenase (LDH) genes and proteins using genome sequence databanks. Human LDHA, LDHC and LDH6A genes were located in tandem on chromosome 11, while LDH6B and LDH6C genes were on chromosomes 15 and 12, respectively. Opossum LDHC and LDH6B genes were located in tandem with the opossum LDHA gene on chromosome 5 and contained 7 (LDHA and LDHC) or 8 (LDH6B) exons. An amino acid sequence prediction for the opossum LDH6B subunit gave an extended N-terminal sequence, similar to the human and mouse LDH6B sequences, which may support the export of this enzyme into mitochondria. The platypus genome contained at least 3 LDH genes encoding LDHA, LDHB and LDH6B subunits. Phylogenetic studies and sequence analyses indicated that LDHA, LDHB and LDH6B genes are present in all mammalian genomes examined, including a monotreme species (platypus), whereas the LDHC gene may have arisen more recently in marsupial mammals. PMID:19679512

  13. Adaptations in lactate dehydrogenase and its isozymes in aging mammalian myocardium: interaction of exercise and temperature.

    PubMed

    Prathima, S; Devi, S A

    1999-04-01

    The responses of the left and right ventricles (LV and RV) to physical conditioning in cold (25 degrees C) and thermoneutral temperatures (35 degrees C), with special reference to lactate dehydrogenase (LDH) and its isoenzyme profile, were studied in the 2-month (young)- and 12-month (middle-aged)-old rats. Moderate hypertrophy was a common observation irrespective of age, region and swim temperature. LV, however, hypertrophied to a significantly lesser extent in the middle-aged, than the RV. Blood Lactate (La) content showed a decline in the trained rather than their untrained counterparts. LDH activity decreased with age. Swim training induced elevations in the enzyme activity. The isoenzyme profile was suitably and efficiently altered in the LV and RV of trained animals to meet the arising O2 demands. The above adaptations were best seen in the young and in the animals trained at thermoneutral temperatures. Thus it is suggested that young age is very apt for initiation of training programs although middle-age is not so late. Swimming in water near body temperature is emphasised as a more preferred environment to cold water, in order to derive maximal exercise-associated beneficial effects.

  14. Malate dehydrogenase of the cytosol. A kinetic investigation of the reaction mechanism and a comparison with lactate dehydrogenase.

    PubMed Central

    Lodola, A; Shore, J D; Parker, D M; Holbrook, J

    1978-01-01

    1. The mechanisms of the reduction of oxaloacetate and of 3-fluoro-oxaloacetate by NADH catalysed by cytoplasmic pig heart malate dehydrogenase (MDH) were investigated. 2. One mol of dimeric enzyme produces 1.7+/-0.4 mol of enzyme-bound NADH when mixed with saturating NAD+ and L-malate at a rate much higher than the subsequent turnover at pH 7.5. 3. Transient measurements of protein and nucleotide fluorescence show that the steady-state complex in the forward direction is MDH-NADH and in the reverse direction MDH-NADH-oxaloacetate. 4. The rate of dissociation of MDH-NADH was measured and is the same as Vmax. in the forward direction at pH 7.5. Both NADH-binding sites are kinetically equivalent. The rate of dissociation varies with pH, as does the equilibrium binding constant for NADH. 5. 3-Fluoro-oxaloacetate is composed of three forms (F1, F2 and S) of which F1 and F2 are immediately substrates for the enzyme. The third form, S, is not a substrate, but when the F forms are used up form S slowly and non-enzymically equilibrates to yield the active substrate forms. S is 2,2-dihydroxy-3-fluorosuccinate. 6. The steady-state compound during the reduction of form F1 is an enzyme form that does not contain NADH, probably MDH-NAD+-fluoromalate. The steady-state compound for form F2 is an enzyme form containing NADH, probably MDH-NADH-fluoro-oxaloacetate. 7. The rate-limiting reaction in the reduction of form F2 shows a deuterium isotope rate ratio of 4 when NADH is replaced by its deuterium analogue, and the rate-limiting reaction is concluded to be hydride transfer. 8. A novel titration was used to show that dimeric cytoplasmic malate dehydrogenase contains two sites that can rapidly reduce the F1 form of 3-fluoro-oxaloacetate. The enzyme shows 'all-of-the-sites' behaviour. 9. Partial mechanisms are proposed to explain the enzyme-catalysed transformations of the natural and the fluoro substrates. These mechanisms are similar to the mechanism of pig heart lactate

  15. Inhibiting Sperm Pyruvate Dehydrogenase Complex and Its E3 Subunit, Dihydrolipoamide Dehydrogenase Affects Fertilization in Syrian Hamsters

    PubMed Central

    Sailasree, Purnima; Singh, Durgesh K.; Kameshwari, Duvurri B.; Shivaji, Sisinthy

    2014-01-01

    Background/Aims The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc) and its E3 subunit, dihydrolipoamide dehydrogenase (DLD) in hamster in vitro fertilization (IVF) via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. Methodology and Principal Findings Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid). Oocytes fertilized with MICA-treated (MT) [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. Conclusions This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In addition, the

  16. Influence of disposable, concentric needle electrodes on muscle enzyme and lactate serum levels.

    PubMed

    Finsterer, Josef; Mittendorfer, Bettina; Neuhuber, Werner; Löscher, Wolfgang N

    2002-08-01

    Several studies addressed the question whether needle-EMG causes elevation of muscle enzymes [aspartate-aminotransferase, alanine-aminotransferase, lactate-dehydrogenase, creatine-phosphokinase (CPK), isoenzyme-MB, aldolase] and lactate with conflicting results. However, these studies used sterilizable needle electrodes and different protocols and methods to record EMGs and determine muscle enzymes. This study examined if muscle enzymes are elevated immediately after or 24 h following EMGs with disposable, concentric needle-electrodes, and if they are dependent on age, sex, muscle, number of investigated sites and previous CPK-elevation. In 53 subjects, 24 woman, 29 men, aged 17-88 years, muscle enzymes were determined before, immediately after and 24 h following EMG with disposable, concentric needle-electrodes. Muscle enzymes were not different before, immediately after and 24 h following the EMG. Muscle enzymes were not different between patients 60 years of age. Apart from higher CPK in men than women, muscle enzymes were not different between the genders. Apart from CPK, muscle enzymes were not different between the brachial biceps and anterior tibial muscle. Muscle enzymes were not different if 20 sites were investigated and were independent on pre-EMG CPK-levels. In conclusion this study shows that muscle enzymes do not increase immediately or 24 h following EMG with disposable, concentric needle-electrodes, irrespective of age, gender, muscle, number of investigated sites and pre-EMG CK-levels.

  17. Contributory roles of two l-lactate dehydrogenases for l-lactic acid production in thermotolerant Bacillus coagulans

    PubMed Central

    Sun, Lifan; Zhang, Caili; Lyu, Pengcheng; Wang, Yanping; Wang, Limin; Yu, Bo

    2016-01-01

    Thermotolerant Bacillus coagulans is considered to be a more promising producer for bio-chemicals, due to its capacity to withstand harsh conditions. Two L-lactate dehydrogenase (LDH) encoding genes (ldhL1 and ldhL2) and one D-LDH encoding gene (ldhD) were annotated from the B. coagulans DSM1 genome. Transcriptional analysis revealed that the expression of ldhL2 was undetectable while the ldhL1 transcription level was much higher than that of ldhD at all growth phases. Deletion of the ldhL2 gene revealed no difference in fermentation profile compared to the wild-type strain, while ldhL1 single deletion or ldhL1ldhL2 double deletion completely blocked L-lactic acid production. Complementation of ldhL1 in the above knockout strains restored fermentation profiles to those observed in the wild-type strain. This study demonstrates ldhL1 is crucial for L-lactic acid production and NADH balance in B. coagulans DSM1 and lays the fundamental for engineering the thermotolerant B. coagulans strain as a platform chemicals producer. PMID:27885267

  18. Development of L-lactate dehydrogenase biosensor based on porous silicon resonant microcavities as fluorescence enhancers.

    PubMed

    Jenie, S N Aisyiyah; Prieto-Simon, Beatriz; Voelcker, Nicolas H

    2015-12-15

    The up-regulation of L-lactate dehydrogenase (LDH), an intracellular enzyme present in most of all body tissues, is indicative of several pathological conditions and cellular death. Herein, we demonstrate LDH detection using porous silicon (pSi) microcavities as a luminescence-enhancing optical biosensing platform. Non-fluorescent resazurin was covalently attached onto the pSi surface via thermal hydrocarbonisation, thermal hydrosylilation and acylation. Each surface modification step was confirmed by means of FTIR and the optical shifts of the resonance wavelength of the microcavity. Thermal hydrocarbonisation also afforded excellent surface stability, ensuring that the resazurin was not reduced on the pSi surface. Using a pSi microcavity biosensor, the fluorescence signal upon detection of LDH was amplified by 10 and 5-fold compared to that of a single layer and a detuned microcavity, respectively, giving a limit of detection of 0.08 U/ml. The biosensor showed a linear response between 0.16 and 6.5 U/ml, covering the concentration range of LDH in normal as well as damaged tissues. The biosensor was selective for LDH and did not produce a signal upon incubation with another NAD-dependant enzyme L-glutamic dehydrogenase. The use of the pSi microcavity as a sensing platform reduced reagent usage by 30% and analysis time threefold compared to the standard LDH assay in solution. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Physiological and fermentation properties of Bacillus coagulans and a mutant lacking fermentative lactate dehydrogenase activity.

    PubMed

    Su, Yue; Rhee, Mun Su; Ingram, Lonnie O; Shanmugam, K T

    2011-03-01

    Bacillus coagulans, a sporogenic lactic acid bacterium, grows optimally at 50-55 °C and produces lactic acid as the primary fermentation product from both hexoses and pentoses. The amount of fungal cellulases required for simultaneous saccharification and fermentation (SSF) at 55 °C was previously reported to be three to four times lower than for SSF at the optimum growth temperature for Saccharomyces cerevisiae of 35 °C. An ethanologenic B. coagulans is expected to lower the cellulase loading and production cost of cellulosic ethanol due to SSF at 55 °C. As a first step towards developing B. coagulans as an ethanologenic microbial biocatalyst, activity of the primary fermentation enzyme L-lactate dehydrogenase was removed by mutation (strain Suy27). Strain Suy27 produced ethanol as the main fermentation product from glucose during growth at pH 7.0 (0.33 g ethanol per g glucose fermented). Pyruvate dehydrogenase (PDH) and alcohol dehydrogenase (ADH) acting in series contributed to about 55% of the ethanol produced by this mutant while pyruvate formate lyase and ADH were responsible for the remainder. Due to the absence of PDH activity in B. coagulans during fermentative growth at pH 5.0, the l-ldh mutant failed to grow anaerobically at pH 5.0. Strain Suy27-13, a derivative of the l-ldh mutant strain Suy27, that produced PDH activity during anaerobic growth at pH 5.0 grew at this pH and also produced ethanol as the fermentation product (0.39 g per g glucose). These results show that construction of an ethanologenic B. coagulans requires optimal expression of PDH activity in addition to the removal of the LDH activity to support growth and ethanol production.

  20. Changes in lactate dehydrogenase are associated with central gray matter lesions in newborns with hypoxic-ischemic encephalopathy.

    PubMed

    Yum, Sook Kyung; Moon, Cheong-Jun; Youn, Young-Ah; Sung, In Kyung

    2017-05-01

    Biomarkers may predict neurological prognosis in infants with hypoxic-ischemic encephalopathy (HIE). We evaluated the relationship between serum lactate dehydrogenase (LDH) and brain magnetic resonance imaging (MRI), which predicts neurodevelopmental outcomes, in order to assess whether LDH levels are similarly predictive. Medical records were reviewed for infants with HIE and LDH levels were assessed on the first (LDH 1 ) and third (LDH 3 ) days following birth. Receiver operating characteristic curves were obtained in relation to central gray matter hypoxic-ischemic lesions. Of 92 patients, 52 (56.5%) had hypoxic-ischemic lesions on brain MRI, and 21 of these infants (40.4%) had central gray matter lesions. LDH 1 and LDH 3 did not differ; however, the percentage change (ΔLDH%) was significantly higher in infants with central gray matter lesions (36.9% versus 6.6%, p = 0.006). With cutoffs of 187 (IU/L, ΔLDH) and 19.4 (%, ΔLDH%), the sensitivity, specificity, positive predictive value and negative predictive value were 71.4, 69.0, 40.5 and 89.1%, respectively. The relative risk was 5.57 (p = 0.001). Changes in serum LDH may be a useful biomarker for predicting future neurodevelopmental prognosis in infants with HIE.

  1. Metabolic Engineering of Escherichia coli K12 for Homofermentative Production of L-Lactate from Xylose.

    PubMed

    Jiang, Ting; Zhang, Chen; He, Qin; Zheng, Zhaojuan; Ouyang, Jia

    2018-02-01

    The efficient utilization of xylose is regarded as a technical barrier to the commercial production of bulk chemicals from biomass. Due to the desirable mechanical properties of polylactic acid (PLA) depending on the isomeric composition of lactate, biotechnological production of lactate with high optical pure has been increasingly focused in recent years. The main objective of this work was to construct an engineered Escherichia coli for the optically pure L-lactate production from xylose. Six chromosomal deletions (pflB, ldhA, ackA, pta, frdA, adhE) and a chromosomal integration of L-lactate dehydrogenase-encoding gene (ldhL) from Bacillus coagulans was involved in construction of E. coli KSJ316. The recombinant strain could produce L-lactate from xylose resulting in a yield of 0.91 g/g xylose. The chemical purity of L-lactate was 95.52%, and the optical purity was greater than 99%. Moreover, three strategies, including overexpression of L-lactate dehydrogenase, intensification of xylose catabolism, and addition of additives to medium, were designed to enhance the production. The results showed that they could increase the concentration of L-lactate by 32.90, 20.13, and 233.88% relative to the control, respectively. This was the first report that adding formate not only could increase the xylose utilization but also led to the fewer by-product levels.

  2. Specific Inhibition of Hepatic Lactate Dehydrogenase Reduces Oxalate Production in Mouse Models of Primary Hyperoxaluria.

    PubMed

    Lai, Chengjung; Pursell, Natalie; Gierut, Jessica; Saxena, Utsav; Zhou, Wei; Dills, Michael; Diwanji, Rohan; Dutta, Chaitali; Koser, Martin; Nazef, Naim; Storr, Rachel; Kim, Boyoung; Martin-Higueras, Cristina; Salido, Eduardo; Wang, Weimin; Abrams, Marc; Dudek, Henryk; Brown, Bob D

    2018-06-15

    Primary hyperoxalurias (PHs) are autosomal recessive disorders caused by the overproduction of oxalate leading to calcium oxalate precipitation in the kidney and eventually to end-stage renal disease. One promising strategy to treat PHs is to reduce the hepatic production of oxalate through substrate reduction therapy by inhibiting liver-specific glycolate oxidase (GO), which controls the conversion of glycolate to glyoxylate, the proposed main precursor to oxalate. Alternatively, diminishing the amount of hepatic lactate dehydrogenase (LDH) expression, the proposed key enzyme responsible for converting glyoxylate to oxalate, should directly prevent the accumulation of oxalate in PH patients. Using RNAi, we provide the first in vivo evidence in mammals to support LDH as the key enzyme responsible for converting glyoxylate to oxalate. In addition, we demonstrate that reduction of hepatic LDH achieves efficient oxalate reduction and prevents calcium oxalate crystal deposition in genetically engineered mouse models of PH types 1 (PH1) and 2 (PH2), as well as in chemically induced PH mouse models. Repression of hepatic LDH in mice did not cause any acute elevation of circulating liver enzymes, lactate acidosis, or exertional myopathy, suggesting further evaluation of liver-specific inhibition of LDH as a potential approach for treating PH1 and PH2 is warranted. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Homo-D-lactic acid fermentation from arabinose by redirection of the phosphoketolase pathway to the pentose phosphate pathway in L-lactate dehydrogenase gene-deficient Lactobacillus plantarum.

    PubMed

    Okano, Kenji; Yoshida, Shogo; Tanaka, Tsutomu; Ogino, Chiaki; Fukuda, Hideki; Kondo, Akihiko

    2009-08-01

    Optically pure d-lactic acid fermentation from arabinose was achieved by using the Lactobacillus plantarum NCIMB 8826 strain whose l-lactate dehydrogenase gene was deficient and whose phosphoketolase gene was substituted with a heterologous transketolase gene. After 27 h of fermentation, 38.6 g/liter of d-lactic acid was produced from 50 g/liter of arabinose.

  4. Blood lactate levels in 31 female dogs with pyometra

    PubMed Central

    Hagman, Ragnvi; Reezigt, Bert Jan; Bergström Ledin, Hanna; Karlstam, Erika

    2009-01-01

    Background Canine pyometra is a life-threatening disease common in countries where spaying of dogs is not routinely performed. The disease is associated with endotoxemia, sepsis, systemic inflammatory response syndrome (SIRS) and a 3–4% mortality rate. Blood lactate analysis is clinically valuable in predicting prognosis and survival, evaluating tissue perfusion and treatment response in human and veterinary critical care settings. The aims of the present study were to investigate 1) the blood lactate levels of female dogs with pyometra by a hand-held analyser and 2) if these levels are related with the clinical status or other biochemical or hematological disorders. Methods In total 31 female dogs with pyometra admitted for surgical ovariohysterectomy and 16 healthy female control dogs were included in the present study. A complete physical examination including SIRS-status determination was performed. Blood samples for lactate concentrations, hematological and biochemical parameters, acid-base and blood gas analysis and other laboratory parameters were collected and subsequently analysed. The diagnosis pyometra was verified with histopathological examination of the uterus and ovaries. Increased hospitalisation length and presence of SIRS were used as indicators of outcome. Results In the pyometra group the median blood lactate level was 1,6 mmol l-1 (range <0.8–2.7 mmol l-1). In the control group the median lactate level was 1,2 mmol l-1 (range <0.8–2.1 mmol l-1). Of the 31 bitches 19 (61%) fulfilled 2 or more criteria for SIRS at inclusion, 10 bitches (32%) fulfilled 3 of the SIRS criteria whereas none accomplished more than 3 criteria. Lactate levels did not differ significantly between the pyometra and control group, or between the SIRS positive and SIRS negative dogs with pyometra. Increased lactate concentration (>2.5 mmol l-1) was demonstrated in one female dog with pyometra (3%), and was not associated with longer hospitalisation or presence of SIRS

  5. Plasma Lactate Dehydrogenase Levels Predict Mortality in Acute Aortic Syndromes: A Diagnostic Accuracy and Observational Outcome Study.

    PubMed

    Morello, Fulvio; Ravetti, Anna; Nazerian, Peiman; Liedl, Giovanni; Veglio, Maria Grazia; Battista, Stefania; Vanni, Simone; Pivetta, Emanuele; Montrucchio, Giuseppe; Mengozzi, Giulio; Rinaldi, Mauro; Moiraghi, Corrado; Lupia, Enrico

    2016-02-01

    In acute aortic syndromes (AAS), organ malperfusion represents a key event impacting both on diagnosis and outcome. Increased levels of plasma lactate dehydrogenase (LDH), a biomarker of malperfusion, have been reported in AAS, but the performance of LDH for the diagnosis of AAS and the relation of LDH with outcome in AAS have not been evaluated so far.This was a bi-centric prospective diagnostic accuracy study and a cohort outcome study. From 2008 to 2014, patients from 2 Emergency Departments suspected of having AAS underwent LDH assay at presentation. A final diagnosis was obtained by aortic imaging. Patients diagnosed with AAS were followed-up for in-hospital mortality.One thousand five hundred seventy-eight consecutive patients were clinically eligible, and 999 patients were included in the study. The final diagnosis was AAS in 201 (20.1%) patients. Median LDH was 424 U/L (interquartile range [IQR] 367-557) in patients with AAS and 383 U/L (IQR 331-460) in patients with alternative diagnoses (P < 0.001). Using a cutoff of 450 U/L, the sensitivity of LDH for AAS was 44% (95% confidence interval [CI] 37-51) and the specificity was 73% (95% CI 69-76). Overall in-hospital mortality for AAS was 23.8%. Mortality was 32.6% in patients with LDH ≥ 450 U/L and 16.8% in patients with LDH < 450 U/L (P = 0.006). Following stratification according to LDH quartiles, in-hospital mortality was 12% in the first (lowest) quartile, 18.4% in the second quartile, 23.5% in the third quartile, and 38% in the fourth (highest) quartile (P = 0.01). LDH ≥ 450 U/L was further identified as an independent predictor of death in AAS both in univariate and in stepwise logistic regression analyses (odds ratio 2.28, 95% CI 1.11-4.66; P = 0.025), in addition to well-established risk markers such as advanced age and hypotension. Subgroup analysis showed excess mortality in association with LDH ≥ 450 U/L in elderly, hemodynamically stable and in nonsurgically

  6. D-Lactate transport and metabolism in rat liver mitochondria.

    PubMed

    de Bari, Lidia; Atlante, Anna; Guaragnella, Nicoletta; Principato, Giovanni; Passarella, Salvatore

    2002-07-15

    In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize D-lactate. We found the following: (1) externally added D-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation)=2] and membrane potential (Delta(psi)) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by alpha-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (D-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate D-lactate traffic across the mitochondrial inner membrane: the D-lactate/H(+) symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the D-lactate/oxoacid antiporter (which mediates both the D-lactate/pyruvate and D-lactate/oxaloacetate exchanges) and D-lactate/malate antiporter studied by monitoring photometrically the appearance of the D-lactate counteranions outside mitochondria. The D-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the V(max) values and in the inhibition and pH profiles and were shown to regulate mitochondrial D-lactate metabolism in vitro. The D-lactate translocators and the D-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for D-lactate-dependent gluconeogenesis.

  7. CONVERSION OF LACTATE-C14 TO PROPIONATE BY THE RUMEN MICROFLORA12

    PubMed Central

    Baldwin, R. L.; Wood, W. A.; Emery, R. S.

    1962-01-01

    Baldwin, R. L. (Michigan State University, East Lansing), W. A. Wood, and R. S. Emery. Conversion of lactate-C14 to propionate by the rumen microflora. J. Bacteriol. 83:907–913. 1962.—Rumen microflora enriched on five different diets calculated to present increasing carbohydrate or lactate availability were used to determine the contribution of the randomizing (succinate) and nonrandomizing (acrylate) routes to propionate with lactate-2-C14 and -3-C14 as substrates. Propionate was labeled as though 70 to 90% was formed via the nonrandomizing route. This percentage was highest on diets containing high levels of carbohydrate or lactate or both. Evidence for the presence of succinic dehydrogenase, acetokinase, phosphotransacetylase, and coenzyme A transphorase was obtained with cell-free extracts. Propionate-2-C14 and lactate-2-C14 were converted by extracts to the activated derivatives of acrylate, lactate, propionate, and acetate. PMID:13864343

  8. 21 CFR 862.1440 - Lactate dehydrogenase test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... dehydrogenase measurements are used in the diagnosis and treatment of liver diseases such as acute viral hepatitis, cirrhosis, and metastatic carcinoma of the liver, cardiac diseases such as myocardial infarction...

  9. Estrogen-Related Receptor Alpha Modulates Lactate Dehydrogenase Activity in Thyroid Tumors

    PubMed Central

    Mirebeau-Prunier, Delphine; Le Pennec, Soazig; Jacques, Caroline; Fontaine, Jean-Fred; Gueguen, Naig; Boutet-Bouzamondo, Nathalie; Donnart, Audrey; Malthièry, Yves; Savagner, Frédérique

    2013-01-01

    Metabolic modifications of tumor cells are hallmarks of cancer. They exhibit an altered metabolism that allows them to sustain higher proliferation rates in hostile environment outside the cell. In thyroid tumors, the expression of the estrogen-related receptor α (ERRα), a major factor of metabolic adaptation, is closely related to the oxidative metabolism and the proliferative status of the cells. To elucidate the role played by ERRα in the glycolytic adaptation of tumor cells, we focused on the regulation of lactate dehydrogenases A and B (LDHA, LDHB) and the LDHA/LDHB ratio. Our study included tissue samples from 10 classical and 10 oncocytic variants of follicular thyroid tumors and 10 normal thyroid tissues, as well as samples from three human thyroid tumor cell lines: FTC-133, XTC.UC1 and RO82W-1. We identified multiple cis-acting promoter elements for ERRα, in both the LDHA and LDHB genes. The interaction between ERRα and LDH promoters was confirmed by chromatin immunoprecipitation assays and in vitro analysis for LDHB. Using knock-in and knock-out cellular models, we found an inverse correlation between ERRα expression and LDH activity. This suggests that thyroid tumor cells may reprogram their metabolic pathways through the up-regulation of ERRα by a process distinct from that proposed by the recently revisited Warburg hypothesis. PMID:23516535

  10. Secondary metabolites of Mirabilis jalapa structurally inhibit Lactate Dehydrogenase A in silico: a potential cancer treatment

    NASA Astrophysics Data System (ADS)

    Kusumawati, R.; Nasrullah, A. H.; Pesik, R. N.; Muthmainah; Indarto, D.

    2018-03-01

    Altered energy metabolism from phosphorylated oxidation to aerobic glycolysis is one of the cancer hallmarks. Lactate dehydrogenase A (LDHA) is a major enzyme that catalyses pyruvate to lactate in such condition. The aim of this study was to explore LDHA inhibitors derived from Indonesian herbal plants. In this study, LDHA and oxamate molecular structures were obtained from protein data bank. As a standard ligand inhibitor, oxamate was molecularly re-validated using Autodock Vina 1.1.2 software and showed binding energy -4.26 ± 0.006 kcal/mol and interacted with LDHA at Gln99, Arg105, Asn137, Arg168, His192, and Thr247 residues. Molecular docking was used to visualize interaction between Indonesian phytochemicals and LDHA. Indonesian phytochemicals with the lowest binding energy and similar residues with standard ligand was Miraxanthin-III (-8.53 ± 0.006 kcal/mol), Vulgaxanthin-I (-8.46 ± 0.006 kcal/mol), Miraxanthin-II (-7.9 ± 0.2 kcal/mol) and Miraxanthin-V (-7.96 ± kcal/mol). Lower energy binding to LDHA and binding site at these residues was predicted to inhibit LDHA activity better than standard ligand. All phytochemicals were found in Mirabilis jalapa plant. Secondary metabolites in Mirabilis jalapa have LDHA inhibitor property in silico. Further in vitro study should be performed to confirm this result.

  11. Trehalose Mediated Inhibition of Lactate Dehydrogenase from Rabbit Muscle. The Application of Kramers' Theory in Enzyme Catalysis.

    PubMed

    Hernández-Meza, Juan M; Sampedro, José G

    2018-04-19

    Lactate dehydrogenase (LDH) catalyzes the reduction of pyruvate to lactate by using NADH. LDH kinetics has been proposed to be dependent on the dynamics of a loop over the active site. Kramers' theory has been useful in the study of enzyme catalysis dependent on large structural dynamics. In this work, LDH kinetics was studied in the presence of trehalose and at different temperatures. In the absence of trehalose, temperature increase raised exponentially the LDH V max and revealed a sigmoid transition of K m toward a low-affinity state similar to protein unfolding. Notably, LDH V max diminished when in the presence of trehalose, while pyruvate affinity increased and the temperature-mediated binding site transition was hindered. The effect of trehalose on k cat was viscosity dependent as described by Kramers' theory since V max correlated inversely with the viscosity of the medium. As a result, activation energy ( E a ) for pyruvate reduction was dramatically increased by trehalose presence. This work provides experimental evidence that the dynamics of a structural component in LDH is essential for catalysis, i.e., the closing of the loop on the active site. While the trehalose mediated-increased of pyruvate affinity is proposed to be due to the compaction and/or increase of structural order at the binding site.

  12. Measurements of C-reactive protein in serum and lactate dehydrogenase in serum and synovial fluid of patients with osteoarthritis.

    PubMed

    Hurter, K; Spreng, D; Rytz, U; Schawalder, P; Ott-Knüsel, F; Schmökel, H

    2005-03-01

    Diagnosis of osteoarthritis (OA) is based upon the clinical orthopaedic examination and the radiographic assessment, both of which can be non-specific and insensitive in early joint disease. The aim of our study was to investigate if there is an increase in serum levels of C-reactive protein (CRP) in degenerative joint disease (DJD) and if CRP could be used to help diagnose OA. We also wished to investigate whether it was possible to distinguish a joint with clinically and radiographically confirmed OA from a healthy joint by comparing lactate dehydrogenase (LDH) levels within the synovial fluid and the serum. We have shown a difference in synovial LDH levels between diseased and healthy joints (P<0.0001). There was also a significant difference between LDH in arthritic synovial fluid and serum, with no correlation between the values. Despite the fact that the values of our clinical patients tended to be higher than the values of our control group (P=0.05) all measured values were within the normal limits of previous publications. From these data, we conclude that single measurements of serum CRP do not permit detection of OA in clinical patients and that serum LDH is not a reliable marker for osteoarthritis. LDH levels in the synovial fluid could be of diagnostic value for identifying osteoarthritis.

  13. Effect of a marathon run on serum lipoproteins, creatine kinase, and lactate dehydrogenase in recreational runners.

    PubMed

    Kobayashi, Yoshio; Takeuchi, Toshiko; Hosoi, Teruo; Yoshizaki, Hidekiyo; Loeppky, Jack A

    2005-12-01

    The objective of this study was to determine the effect of a marathon run on serum lipid and lipoprotein concentrations and serum muscle enzyme activities and follow their recovery after the run. These blood concentrations were measured before, immediately after, and serially after a marathon run in 15 male recreational runners. The triglyceride level was significantly elevated postrace, then fell 30% below baseline 1 day after the run, and returned to baseline after 1 week. Total cholesterol responded less dramatically but with a similar pattern. High-density lipoprotein cholesterol remained significantly elevated and low-density lipoprotein cholesterol was transiently reduced for 3 days after the run. The total cholesterol/high-density cholesterol ratio was significantly lowered for 3 days. Serum lactate dehydrogenase activity significantly doubled postrace and then declined but remained elevated for 2 weeks. Serum creatine kinase activity peaked 24 hr after the run, with a 15-fold rise, and returned to baseline after 1 week. The rise of these enzymes reflects mechanically damaged muscle cells leaking contents into the interstitial fluid. It is concluded that a prolonged strenuous exercise bout in recreational runners, such as a marathon, produces beneficial changes in lipid blood profiles that are significant for only 3 days. However, muscle damage is also evident for 1 week or more from the dramatic and long-lasting effect on enzyme levels. Laboratory values for these runners were outside normal ranges for some days after the race.

  14. Two separate pathways for d-lactate oxidation by Saccharomyces cerevisiae mitochondria which differ in energy production and carrier involvement.

    PubMed

    Pallotta, Maria Luigia; Valenti, Daniela; Iacovino, Michelina; Passarella, Salvatore

    2004-02-15

    In this work we looked at whether and how mitochondria isolated from Saccharomyces cerevisiae (SCM) oxidize d-lactate. We found that: (1). externally added d-lactate causes oxygen uptake by SCM with P/O ratio equal to 1.5; in the presence of antimycin A (AA), P/O ratio was 1.8, differently in the presence of the non-penetrant alpha-cyanocinnamate (alpha-CCN-) no P/O ratio could be measured. Consistently, mitochondrial electrical membrane potential (deltapsi) generation was found, due to externally added d-lactate in the presence of antimycin A, but not of alpha-CCN-. (2). SCM oxidize d-lactate in two different manners: (i). via inner membrane d-lactate dehydrogenase which leads to d-lactate oxidation without driving deltapsi generation and ATP synthesis and (ii). via the matrix d-lactate dehydrogenase, which drives deltapsi generation and ATP synthesis by using taken up d-lactate. (3). Pyruvate newly synthesised in the mitochondrial matrix is exported via the novel d-lactate/pyruvate antiporter. d-Lactate/pyruvate antiport proved to regulate the rate of pyruvate efflux in vitro. (4). The existence of the d-lactate/H+ symporter is also proposed as shown by mitochondrial swelling. The d-lactate carriers and d-lactate dehydrogenases could account for the removal of the toxic methylglyoxal from cytosol, as well as for the d-lactate-dependent gluconeogenesis.

  15. Blood lactate accumulation in top level swimmers following competition.

    PubMed

    Bonifazi, M; Martelli, G; Marugo, L; Sardella, F; Carli, G

    1993-03-01

    The purposes of this study were to evaluate the significance of blood lactate values after competitions and the blood lactate-swimming speed relationship to swimming performances. Auricular blood samples (N = 421) were collected in 203 top level Italian swimmers (116 males and 87 females) at the end of competitions performed in a 25 m swimming pool. The distribution of all lactate values differed between males and females. The lowest lactate values occurred in swimmers performing the longest distances both in males (1500 m) and females (800 m). In swimmers performing freestyle events a relationship between V-4 mM (swimming speed at 4 mmol/l blood lactate value) and competition velocities was observed, in males, at 200, 400 and 1500 m and, in females, at 400 and 800 m. The predicted velocity corresponding to the competition lactate value assessed by the individual blood lactate-swimming speed relationship was found to be highly related to the actual competition velocity. Results suggest that blood lactate values in swimmers are a useful indication of individual aptitudes.

  16. Blocking Lactate Export by Inhibiting the Myc Target MCT1 Disables Glycolysis and Glutathione Synthesis

    PubMed Central

    Doherty, Joanne R.; Yang, Chunying; Scott, Kristen E. N.; Cameron, Michael D.; Fallahi, Mohammad; Li, Weimin; Hall, Mark A.; Amelio, Antonio L.; Mishra, Jitendra K.; Li, Fangzheng; Tortosa, Mariola; Genau, Heide Marika; Rounbehler, Robert J.; Lu, Yunqi; Dang, Chi. V.; Kumar, K. Ganesh; Butler, Andrew A.; Bannister, Thomas D.; Hooper, Andrea T.; Unsal-Kacmaz, Keziban; Roush, William R.; Cleveland, John L.

    2014-01-01

    Myc oncoproteins induce genes driving aerobic glycolysis, including lactate dehydrogenase-A that generates lactate. Here we report that Myc controls transcription of the lactate transporter SLC16A1/MCT1, and that elevated MCT1 levels are manifest in premalignant and neoplastic Eμ-Myc transgenic B cells and in human malignancies with MYC or MYCN involvement. Notably, disrupting MCT1 function leads to an accumulation of intracellular lactate that rapidly disables tumor cell growth and glycolysis, provoking marked alterations in glycolytic intermediates, and reductions in glucose transport, and in levels of ATP, NADPH and glutathione. Reductions in glutathione then lead to increases in hydrogen peroxide, mitochondrial damage and, ultimately, cell death. Finally, forcing glycolysis by metformin treatment augments this response and the efficacy of MCT1 inhibitors, suggesting an attractive combination therapy for MYC/MCT1-expressing malignancies. PMID:24285728

  17. Blocking lactate export by inhibiting the Myc target MCT1 Disables glycolysis and glutathione synthesis.

    PubMed

    Doherty, Joanne R; Yang, Chunying; Scott, Kristen E N; Cameron, Michael D; Fallahi, Mohammad; Li, Weimin; Hall, Mark A; Amelio, Antonio L; Mishra, Jitendra K; Li, Fangzheng; Tortosa, Mariola; Genau, Heide Marika; Rounbehler, Robert J; Lu, Yunqi; Dang, Chi V; Kumar, K Ganesh; Butler, Andrew A; Bannister, Thomas D; Hooper, Andrea T; Unsal-Kacmaz, Keziban; Roush, William R; Cleveland, John L

    2014-02-01

    Myc oncoproteins induce genes driving aerobic glycolysis, including lactate dehydrogenase-A that generates lactate. Here, we report that Myc controls transcription of the lactate transporter SLC16A1/MCT1 and that elevated MCT1 levels are manifest in premalignant and neoplastic Eμ-Myc transgenic B cells and in human malignancies with MYC or MYCN involvement. Notably, disrupting MCT1 function leads to an accumulation of intracellular lactate that rapidly disables tumor cell growth and glycolysis, provoking marked alterations in glycolytic intermediates, reductions in glucose transport, and in levels of ATP, NADPH, and ultimately, glutathione (GSH). Reductions in GSH then lead to increases in hydrogen peroxide, mitochondrial damage, and ultimately, cell death. Finally, forcing glycolysis by metformin treatment augments this response and the efficacy of MCT1 inhibitors, suggesting an attractive combination therapy for MYC/MCT1-expressing malignancies.

  18. Regulator LdhR and d-Lactate Dehydrogenase LdhA of Burkholderia multivorans Play Roles in Carbon Overflow and in Planktonic Cellular Aggregate Formation.

    PubMed

    Silva, Inês N; Ramires, Marcelo J; Azevedo, Lisa A; Guerreiro, Ana R; Tavares, Andreia C; Becker, Jörg D; Moreira, Leonilde M

    2017-10-01

    LysR-type transcriptional regulators (LTTRs) are the most commonly found regulators in Burkholderia cepacia complex, comprising opportunistic pathogens causing chronic respiratory infections in cystic fibrosis (CF) patients. Despite LTTRs being global regulators of pathogenicity in several types of bacteria, few have been characterized in Burkholderia Here, we show that gene ldhR of B. multivorans encoding an LTTR is cotranscribed with ldhA encoding a d-lactate dehydrogenase and evaluate their implication in virulence traits such as exopolysaccharide (EPS) synthesis and biofilm formation. A comparison of the wild type (WT) and its isogenic Δ ldhR mutant grown in medium with 2% d-glucose revealed a negative impact on EPS biosynthesis and on cell viability in the presence of LdhR. The loss of viability in WT cells was caused by intracellular acidification as a consequence of the cumulative secretion of organic acids, including d-lactate, which was absent from the Δ ldhR mutant supernatant. Furthermore, LdhR is implicated in the formation of planktonic cellular aggregates. WT cell aggregates reached 1,000 μm in size after 24 h in liquid cultures, in contrast to Δ ldhR mutant aggregates that never grew more than 60 μm. The overexpression of d-lactate dehydrogenase LdhA in the Δ ldhR mutant partially restored the formed aggregate size, suggesting a role for fermentation inside aggregates. Similar results were obtained for surface-attached biofilms, with WT cells producing more biofilm. A systematic evaluation of planktonic aggregates in Burkholderia CF clinical isolates showed aggregates in 40 of 74. As CF patients' lung environments are microaerophilic and bacteria are found as free aggregates/biofilms, LdhR and LdhA might have central roles in adapting to this environment. IMPORTANCE Cystic fibrosis patients often suffer from chronic respiratory infections caused by several types of microorganisms. Among them are the Burkholderia cepacia complex bacteria, which

  19. Myasthenia gravis: long-term prognostic value of thymus lactate dehydrogenase isoenzyme pattern of hyperplastic thymus and thymoma.

    PubMed Central

    Szathmáry, I; Selmeci, L; Pósch, E; Szobor, A; Molnár, J

    1985-01-01

    Lactate dehydrogenase (LDH) isoenzyme pattern and the percent of H-subunit content were determined in the thymus of 62 patients (55 with hyperplasia, 7 with tumours) after thymectomy. An increase in LDH1 relative activity indicates that in the thymus of patients with myasthenia gravis the ratio of mature differentiated thymocytes was higher than in the thymus of control subjects. LDH isoenzyme profiles of thymus tumours were similar to those described in other neoplasms, except that thymomas with apparent predominance of epithelial cells and with minimal lymphocytic reaction exhibited a marked elevation only in LDH2 relative activity, presumably associated with the specific (secretory) function of epithelial cells. The elevation of H-subunit content, a parameter characteristic of both thymic components (lymphoid and epithelial), correlated closely with a poor clinical condition in patients several years after surgery. PMID:4031927

  20. Variants of glycerol dehydrogenase having D-lactate dehydrogenase activity and uses thereof

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Qingzhao; Shanmugam, Keelnatham T.; Ingram, Lonnie O'Neal

    The present invention provides methods of designing and generating glycerol dehydrogenase (GlyDH) variants that have altered function as compared to a parent polypeptide. The present invention further provides nucleic acids encoding GlyDH polypeptide variants having altered function as compared to the parent polypeptide. Host cells comprising polynucleotides encoding GlyDH variants and methods of producing lactic acids are also provided in various aspects of the invention.

  1. Stimulation of d- and l-lactate dehydrogenases transcriptional levels in presence of diammonium hydrogen phosphate resulting to enhanced lactic acid production by Lactobacillus strain.

    PubMed

    Singhvi, Mamata; Zendo, Takeshi; Iida, Hiroshi; Gokhale, Digambar; Sonomoto, Kenji

    2017-12-01

    The present study revealed the effect of nitrogen sources on lactic acid production and stimulation of d- and l-lactate dehydrogenases (LDH) of parent Lactobacillus lactis NCIM 2368 and its mutant RM2-24 generated after UV mutagenesis. Both the parent and mutant strains were evaluated for d-lactic acid production in control and modified media. The modified media did not show remarkable effect on lactic acid production in case of parent whereas mutant exhibited significant enhancement in d-lactic acid production along with the appearance of l-lactic acid in the broth. Both LDH activities and specific activities were found to be higher in mutant than the parent strain. These results suggested that the diammonium hydrogen phosphate in modified media triggered the expression of LDH genes leading to enhanced lactic acid production. This observation has been proved by studying the expression levels of d- and l-LDH genes of parent and mutant in control and modified media using quantitative RT-PCR technique. In case of mutant, the transcriptional levels of d-LDH and l-LDH increased ∼17 fold and ∼1.38 fold respectively in modified medium compared to the values obtained with control medium. In case of parent, no significant change in transcriptional levels of d- and l-LDH was found when the cells were grown in either control medium or modified medium. This study suggested that the mutant, RM2-24 has l-LDH gene which is expressed in presence of (NH 4 ) 2 HPO 4 resulting in l-lactic acid production. Co-production of l-lactic acid in d-lactic acid fermentation may be detrimental in the PLA production. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. [Temperature-switched high-efficiency D-lactate production from glycerol].

    PubMed

    Tian, Kangming; Zhou, Li; Chen, Xianzhong; Shen, Wei; Shi, Guiyang; Singh, Suren; Lu, Fuping; Wang, Zhengxiang

    2013-01-01

    Glycerol from oil hydrolysis industry is being considered as one of the abundent raw materials for fermentation industry. In present study, the aerobic and anaerobic metabolism and growth properties on glycerol by Esherichia coli CICIM B0013-070, a D-lactate over-producing strain constructed previously, at different temperatures were investigated, followed by a novel fermentation process, named temperature-switched process, was established for D-lactate production from glycerol. Under the optimal condition, lactate yield was increased from 64.0% to 82.6%. Subsequently, the yield of D-lactate from glycerol was reached up to 88.9% while a thermo-inducible promoter was used to regulate D-lactate dehydrogenase transcription.

  3. Cytochemical Localization of Glycolate Dehydrogenase in Mitochondria of Chlamydomonas1

    PubMed Central

    Beezley, Belinda B.; Gruber, Peter J.; Frederick, Sue Ellen

    1976-01-01

    Mildly disrupted cells of Chlamydomonas reinhardi Dangeard were incubated in a reaction medium containing glycolate, ferricyanide, and cupric ions, and then processed for electron microscopy. As a result of the cytochemical treatment, an electron opaque product was deposited specifically in the outer compartment of mitochondria; other cellular components, including microbodies, did not accumulate stain. Incubation with d-lactate yielded similar results, while treatment with l-lactate produced only a weak reaction. Oxamate, which inhibits glycolate dehydrogenase activity in cell-free extracts, also inhibited the cytochemical reaction. These findings demonstrate in situ that glycolate dehydrogenase is localized in mitochondria, and thus corroborate similar conclusions reached on the basis of enzymic studies of isolated algal organelles. Images PMID:16659670

  4. Procalcitonin, C-reactive protein and serum lactate dehydrogenase in the diagnosis of bacterial sepsis, SIRS and systemic candidiasis.

    PubMed

    Miglietta, Fabio; Faneschi, Maria Letizia; Lobreglio, Giambattista; Palumbo, Claudio; Rizzo, Adriana; Cucurachi, Marco; Portaccio, Gerolamo; Guerra, Francesco; Pizzolante, Maria

    2015-09-01

    The aim of this study was to evaluate procalcitonin (PCT), C-reactive protein (CRP), platelet count (PLT) and serum lactate dehydrogenase (LDH) as early markers for diagnosis of SIRS, bacterial sepsis and systemic candidiasis in intensive care unit (ICU) patients. Based on blood culture results, the patients were divided into a sepsis group (70 patients), a SIRS group (42 patients) and a systemic candidiasis group (33 patients). PCT, CRP, LDH and PLT levels were measured on day 0 and on day 2 from the sepsis symptom onset. PCT levels were higher in Gram negative sepsis than those in Gram positive sepsis, although the P value between the two subgroups is not significant (P=0.095). Bacterial sepsis group had higher PCT and CRP levels compared with the systemic candidiasis group, whereas PLT and LDH levels showed similar levels in these two subgroups. The AUC for PCT (AUC: 0.892, P <0.001) was larger than for CRP (AUC: 0.738, P <0.001). The best cut-off values for PCT and CRP were 0.99 ng/mL and 76.2 mg/L, respectively. Diagnostic sensitivity and specificity for PCT were 84.3% and 81.8% whereas CRP showed a sensitivity of 77.2% and a specificity of 63.6%. However, PCT was unable to discriminate between SIRS and systemic candidiasis groups (P=0.093 N.S.). In conclusion, PCT can be used as a preliminary marker in the event of clinical suspicion of systemic candidiasis; however, low PCT levels (<0.99 ng/mL) necessarily require the use of other specific markers of candidaemia to confirm the diagnosis, due to great uniformity of PCT levels in systemic candidiasis and SIRS groups.

  5. A membrane-associated adenylate cyclase modulates lactate dehydrogenase and creatine kinase activities required for bull sperm capacitation induced by hyaluronic acid.

    PubMed

    Fernández, Silvina; Córdoba, Mariana

    2017-04-01

    Hyaluronic acid, as well as heparin, is a glycosaminoglycan present in the female genital tract of cattle. The aim of this study was to evaluate oxidative metabolism and intracellular signals mediated by a membrane-associated adenylate cyclase (mAC), in sperm capacitation with hyaluronic acid and heparin, in cryopreserved bull sperm. The mAC inhibitor, 2',5'-dideoxyadenosine, was used in the present study. Lactate dehydrogenase (LDH) and creatine kinase (CK) activities and lactate concentration were determined spectrophotometrically in the incubation medium. Capacitation and acrosome reaction were evaluated by chlortetracycline technique, while plasma membrane and acrosome integrity were determined by trypan blue stain/differential interference contrast microscopy. Heparin capacitated samples had a significant decrease in LDH and CK activities, while in hyaluronic acid capacitated samples LDH and CK activities both increased compared to control samples, in heparin and hyaluronic acid capacitation conditions, respectively. A significant increase in lactate concentration in the incubation medium occurred in hyaluronic acid-treated sperm samples compared to heparin treatment, indicating this energetic metabolite is produced during capacitation. The LDH and CK enzyme activities and lactate concentrations in the incubation medium were decreased with 2',5'-dideoxyadenosine treatment in hyaluronic acid samples. The mAC inhibitor significantly inhibited heparin-induced capacitation of sperm cells, but did not completely inhibit hyaluronic acid capacitation. Therefore, hyaluronic acid and heparin are physiological glycosaminoglycans capable of inducing in vitro capacitation in cryopreserved bull sperm, stimulating different enzymatic pathways and intracellular signals modulated by a mAC. Hyaluronic acid induces sperm capacitation involving LDH and CK activities, thereby reducing oxidative metabolism, and this process is mediated by mAC. Copyright © 2017 Elsevier B.V. All

  6. Change in Lactate Levels After Hemodialysis in Patients With End-Stage Renal Disease.

    PubMed

    Hourmozdi, Justin J; Gill, Jasreen; Miller, Joseph B; Markin, Abraham; Adams, Beth; Soi, Vivek; Jaehne, Anja K; Taylor, Andrew R; Langberg, Sam; Rodriguez, Lauren; Fox, Carynne; Uduman, Junior; Yessayan, Lenar T; Rivers, Emanuel P

    2018-06-01

    Patients with end-stage renal disease commonly visit the emergency department (ED). The purpose of this investigation is to examine the prevalence of baseline abnormal lactate levels and to evaluate the effects of hemodialysis on serum lactate levels. This was a prospective observational cohort study performed at an outpatient dialysis facility at an urban tertiary care hospital. The study consisted of 226 patients with end-stage renal disease who were receiving long-term hemodialysis and were enrolled during a 2-day period at the beginning of December 2015. Blood drawn for lactate levels was immediately analyzed before and after hemodialysis sessions. All patients completed their hemodialysis sessions. The prevalence of an abnormal lactate level (greater than 1.8 mmol/L) before hemodialysis was 17.7% (n=40). Overall, lactate levels decreased by 27% (SD 35%) after hemodialysis, with a decrease of 37% (SD 31%) for subgroups with a lactate level of 1.9 to 2.4 mmol/L, and 62% (SD 14%) with a lactate of 2.5 to 3.9 mmol/L. The data presented help providers understand the prevalence of abnormal lactate values in an outpatient end-stage renal disease population. After hemodialysis, lactate levels decreased significantly. This information may help medical providers interpret lactate values when patients with end-stage renal disease present to the ED. Copyright © 2017 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

  7. Lactic acid-producing yeast cells having nonfunctional L- or D-lactate:ferricytochrome C oxidoreductase cells

    DOEpatents

    Miller, Matthew [Boston, MA; Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Highland Ranch, CO; Hause, Benjamin Matthew [Currie, MN; Van Hoek, Pim [Camarillo, CA; Dundon, Catherine Asleson [Minneapolis, MN

    2012-03-20

    Yeast cells having an exogenous lactate dehydrogenase gene ae modified by reducing L- or D-lactate:ferricytochrome c oxidoreductase activity in the cell. This leads to reduced consumption of lactate by the cell and can increase overall lactate yields in a fermentation process. Cells having the reduced L- or D-lactate:ferricytochrome c oxidoreductase activity can be screened for by resistance to organic acids such as lactic or glycolic acid.

  8. Lactate shuttles in nature.

    PubMed

    Brooks, G A

    2002-04-01

    Once thought to be the consequence of oxygen lack in contracting skeletal muscle, the glycolytic product lactate is formed and utilized continuously under fully aerobic conditions. "Cell-cell" and "intracellular lactate shuttle" concepts describe the roles of lactate in the delivery of oxidative and gluconeogenic substrates, as well as in cell signalling. Examples of cell-cell shuttles include lactate exchanges between white-glycolytic and red-oxidative fibres within a working muscle bed, between working skeletal muscle and heart, and between tissues of net lactate release and gluconeogenesis. Lactate exchange between astrocytes and neurons that is linked to glutamatergic signalling in the brain is an example of a lactate shuttle supporting cell-cell signalling. Lactate uptake by mitochondria and pyruvate-lactate exchange in peroxisomes are examples of intracellular lactate shuttles. Lactate exchange between sites of production and removal is facilitated by monocarboxylate transport proteins, of which there are several isoforms, and, probably, also by scaffolding proteins. The mitochondrial lactate-pyruvate transporter appears to work in conjunction with mitochondrial lactate dehydrogenase, which permits lactate to be oxidized within actively respiring cells. Hence mitochondria function to establish the concentration and proton gradients necessary for cells with high mitochondrial densities (e.g. cardiocytes) to take up and oxidize lactate. Arteriovenous difference measurements on working cardiac and skeletal muscle beds as well as NMR spectral analyses of these tissues show that lactate is formed and oxidized within the cells of formation in vivo. Glycolysis and lactate oxidation within cells permits high flux rates and the maintenance of redox balance in the cytosol and mitochondria. Other examples of intracellular lactate shuttles include lactate uptake and oxidation in sperm mitochondria and the facilitation of beta-oxidation in peroxisomes by pyruvate-lactate

  9. Stability and activity of lactate dehydrogenase on biofunctional layers deposited by activated vapor silanization (AVS) and immersion silanization (IS)

    NASA Astrophysics Data System (ADS)

    Calvo, Jorge Nieto-Márquez; Elices, Manuel; Guinea, Gustavo V.; Pérez-Rigueiro, José; Arroyo-Hernández, María

    2017-09-01

    The interaction between surfaces and biological elements, in particular, proteins is critical for the performance of biomaterials and biosensors. This interaction can be controlled by modifying the surface in a process known as biofunctionalization. In this work, the enzyme lactate dehydrogenase (LDH) is used to study the stability of the interaction between a functional protein and amine-functionalized surfaces. Two different functionalization procedures were compared: Activated Vapor Silanization (AVS) and Immersion Silanization (IS). Adsorption kinetics is shown to follow the Langmuir model for AVS-functionalized samples, while IS-functionalized samples show a certain instability if immersed in an aqueous medium for several hours. In turn, the enzymatic activity of LDH is preserved for longer times by using glutaraldehyde as crosslinker between the AVS biofunctional surface and the enzyme.

  10. Distribution of lactate dehydrogenase in healthy and degenerative canine stifle joint cartilage.

    PubMed

    Walter, Eveline L C; Spreng, David; Schmöckel, Hugo; Schawalder, Peter; Tschudi, Peter; Friess, Armin E; Stoffel, Michael H

    2007-07-01

    In dogs, degenerative joint diseases (DJD) have been shown to be associated with increased lactate dehydrogenase (LDH) activity in the synovial fluid. The goal of this study was to examine healthy and degenerative stifle joints in order to clarify the origin of LDH in synovial fluid. In order to assess the distribution of LDH, cartilage samples from healthy and degenerative knee joints were investigated by means of light and transmission electron microscopy in conjunction with immunolabeling and enzyme cytochemistry. Morphological analysis confirmed DJD. All techniques used corroborated the presence of LDH in chondrocytes and in the interterritorial matrix of healthy and degenerative stifle joints. Although enzymatic activity of LDH was clearly demonstrated in the territorial matrix by means of the tetrazolium-formazan reaction, immunolabeling for LDH was missing in this region. With respect to the distribution of LDH in the interterritorial matrix, a striking decrease from superficial to deeper layers was present in healthy dogs but was missing in affected joints. These results support the contention that LDH in synovial fluid of degenerative joints originates from cartilage. Therefore, we suggest that (1) LDH is transferred from chondrocytes to ECM in both healthy dogs and dogs with degenerative joint disease and that (2) in degenerative joints, LDH is released from chondrocytes and the ECM into synovial fluid through abrasion of cartilage as well as through enhanced diffusion as a result of increased water content and degradation of collagen.

  11. Effect of Exercise-Induced Lactate Elevation on Brain Lactate Levels During Hypoglycemia in Patients With Type 1 Diabetes and Impaired Awareness of Hypoglycemia.

    PubMed

    Wiegers, Evita C; Rooijackers, Hanne M; Tack, Cees J; Groenewoud, Hans J M M; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

    2017-12-01

    Since altered brain lactate handling has been implicated in the development of impaired awareness of hypoglycemia (IAH) in type 1 diabetes, the capacity to transport lactate into the brain during hypoglycemia may be relevant in its pathogenesis. High-intensity interval training (HIIT) increases plasma lactate levels. We compared the effect of HIIT-induced hyperlacticacidemia on brain lactate during hypoglycemia between 1 ) patients with type 1 diabetes and IAH, 2 ) patients with type 1 diabetes and normal awareness of hypoglycemia, and 3 ) healthy participants without diabetes ( n = 6 per group). All participants underwent a hypoglycemic (2.8 mmol/L) clamp after performing a bout of HIIT on a cycle ergometer. Before HIIT (baseline) and during hypoglycemia, brain lactate levels were determined continuously with J-difference-editing 1 H-MRS, and time curves were analyzed using nonlinear mixed-effects modeling. At the beginning of hypoglycemia (after HIIT), brain lactate levels were elevated in all groups but most pronounced in patients with IAH. During hypoglycemia, brain lactate decreased ∼30% below baseline in patients with IAH but returned to baseline levels and remained there in the other two groups. Our results support the concept of enhanced lactate transport as well as increased lactate oxidation in patients with type 1 diabetes and IAH. © 2017 by the American Diabetes Association.

  12. Effect of Controlled Ice Nucleation on Stability of Lactate Dehydrogenase During Freeze-Drying.

    PubMed

    Fang, Rui; Tanaka, Kazunari; Mudhivarthi, Vamsi; Bogner, Robin H; Pikal, Michael J

    2018-03-01

    Several controlled ice nucleation techniques have been developed to increase the efficiency of the freeze-drying process as well as to improve the quality of pharmaceutical products. Owing to the reduction in ice surface area, these techniques have the potential to reduce the degradation of proteins labile during freezing. The objective of this study was to evaluate the effect of ice nucleation temperature on the in-process stability of lactate dehydrogenase (LDH). LDH in potassium phosphate buffer was nucleated at -4°C, -8°C, and -12°C using ControLyo™ or allowed to nucleate spontaneously. Both the enzymatic activity and tetramer recovery after freeze-thawing linearly correlated with product ice nucleation temperature (n = 24). Controlled nucleation also significantly improved batch homogeneity as reflected by reduced inter-vial variation in activity and tetramer recovery. With the correlation established in the laboratory, the degradation of protein in manufacturing arising from ice nucleation temperature differences can be quantitatively predicted. The results show that controlled nucleation reduced the degradation of LDH during the freezing process, but this does not necessarily translate to vastly superior stability during the entire freeze-drying process. The capability of improving batch homogeneity provides potential advantages in scaling-up from lab to manufacturing scale. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Lactate Dehydrogenase Undergoes a Substantial Structural Change to Bind its Substrate

    PubMed Central

    Qiu, Linlin; Gulotta, Miriam; Callender, Robert

    2007-01-01

    Employing temperature-jump relaxation spectroscopy, we investigate the kinetics and thermodynamics of the formation of a very early ternary binding intermediate formed when lactate dehydrogenase (LDH) binds a substrate mimic on its way to forming the productive LDH/NADH·substrate Michaelis complex. Temperature-jump scans show two distinct submillisecond processes are involved in the formation of this ternary binding intermediate, called the encounter complex here. The on-rate of the formation of the encounter complex from LDH/NADH with oxamate (a substrate mimic) is determined as a function of temperature and in the presence of small concentrations of a protein destabilizer (urea) and protein stabilizer (TMAO). It shows a strong temperature dependence with inverse Arrhenius behavior and a temperature-dependent enthalpy (heat capacity of 610 ± 84 cal/Mol K), is slowed in the presence of TMAO and speeded up in the presence of urea. These results suggest that LDH/NADH occupies a range of conformations, some competent to bind substrate (open structure; a minority population) and others noncompetent (closed), in fast equilibrium with each other in accord with a select fit model of binding. From the thermodynamic results, the two species differ in the rearrangement of low energy hydrogen bonds as would arise from changes in internal hydrogen bonding and/or increases in the solvation of the protein structure. The binding-competent species can bind ligand at or very near diffusion-limited speeds, suggesting that the binding pocket is substantially exposed to solvent in these species. This would be in contrast to the putative closed structure where the binding pocket resides deep within the protein interior. PMID:17483169

  14. The determination and arrangement of a combination of enzyme lactate dehydrogenase of bacteria Acinetobacter sp. as a device the identity important bacteria agent composts

    NASA Astrophysics Data System (ADS)

    Sukmawati, D.; Puspitaningrum, R.; Muzajjanah

    2017-07-01

    The number of garbage generated by the industry or society is a usual problem encountered by almost all urban centers, especially large cities such as Jakarta. Waste prevention strategy required quickly and accurately. One strategy for tackling the Junk was getting lactic acid-producing bacteria. It has been shown that lactic acid can increase the acceleration of organic matter such as an overhaul of lignin and cellulose as well as out causing toxic compounds arising from decay. This research will be conducted on the determination and characterization of the enzyme-producing compost bacteria LDH lactate dehydrogenase LDH - which in isolation from the garbage Landfill Rawasari. Methodology: Research carried out consists: isolation of lactic acid-producing bacteria; identification of microscopic, macroscopic and staining Gram; cellulose assay, and optimization of PCR conditions LDH enzymes producing bacteria. Isolation is performed by dilution method and the direct method. As many as 5-point sampling. Each stage is conducted from 10 grams of soil from the top surface of the compost. Isolation results obtained 100 isolate the bacteria. Base on the characteristic of macroscopic and microscopic observations retrieved 14 isolates of bacteria have shaped rods and brought forth a negative kind of Gram positive staining. Bacterial isolates with codes (BK1; BK3; BK4; BK5; BK6; BK7; BK8; BK9; BK10; BK11: BK12; BK 13). The potential bacteria with ability produce lactate dehydrogenase was BK1 and BK3. Base for analysis phylogenetic there was identification bacteria bak1 and bak3 where Acinetobacter sp.

  15. Myoclonic epilepsy with ragged-red fibers without increased lactate levels.

    PubMed

    Kimura, Shigemi; Ozasa, Shiro; Nakamura, Kyoko; Nomura, Keiko; Kosuge, Hirofumi

    2009-07-01

    Myoclonic epilepsy associated with ragged-red fibers is one of the mitochondrial encephalomyopathies. Pathogenic mitochondrial DNA mutations have been identified in the mitochondrial transfer RNA (tRNA)(Lys) at positions 8344 and 8356. Characteristics of myoclonic epilepsy associated with ragged-red fibers include myoclonic epilepsy, generalized epilepsy, hearing loss, exercise intolerance, lactic acidosis, and ragged-red fibers. The elevated lactate level is one of the most important symptoms needed to make a diagnosis of mitochondrial encephalomyopathy. In the present case, however, myoclonic epilepsy was associated with ragged-red fibers but without increased lactate levels. Therefore, myoclonic epilepsy associated with ragged-red fibers should be suspected in a patient who has myoclonic epilepsy that is difficult to control with antiepileptic medications and who has other symptoms of mitochondrial disease, such as mental retardation, even if the patient's lactate level is normal.

  16. Efficient reduction of the formation of by-products and improvement of production yield of 2,3-butanediol by a combined deletion of alcohol dehydrogenase, acetate kinase-phosphotransacetylase, and lactate dehydrogenase genes in metabolically engineered Klebsiella oxytoca in mineral salts medium.

    PubMed

    Jantama, Kaemwich; Polyiam, Pattharasedthi; Khunnonkwao, Panwana; Chan, Sitha; Sangproo, Maytawadee; Khor, Kirin; Jantama, Sirima Suvarnakuta; Kanchanatawee, Sunthorn

    2015-07-01

    Klebsiella oxytoca KMS005 (∆adhE∆ackA-pta∆ldhA) was metabolically engineered to improve 2,3-butanediol (BDO) yield. Elimination of alcohol dehydrogenase E (adhE), acetate kinase A-phosphotransacetylase (ackA-pta), and lactate dehydrogenase A (ldhA) enzymes allowed BDO production as a primary pathway for NADH re-oxidation, and significantly reduced by-products. KMS005 was screened for the efficient glucose utilization by metabolic evolution. KMS005-73T improved BDO production at a concentration of 23.5±0.5 g/L with yield of 0.46±0.02 g/g in mineral salts medium containing 50 g/L glucose in a shake flask. KMS005-73T also exhibited BDO yields of about 0.40-0.42 g/g from sugarcane molasses, cassava starch, and maltodextrin. During fed-batch fermentation, KMS005-73T produced BDO at a concentration, yield, and overall and specific productivities of 117.4±4.5 g/L, 0.49±0.02 g/g, 1.20±0.05 g/Lh, and 27.2±1.1 g/gCDW, respectively. No acetoin, lactate, and formate were detected, and only trace amounts of acetate and ethanol were formed. The strain also produced the least by-products and the highest BDO yield among other Klebsiella strains previously developed. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  17. Characterization of Plasmodium Lactate Dehydrogenase and Histidine-Rich Protein 2 Clearance Patterns via Rapid On-Bead Detection from a Single Dried Blood Spot

    PubMed Central

    Markwalter, Christine F.; Gibson, Lauren E.; Mudenda, Lwiindi; Kimmel, Danielle W.; Mbambara, Saidon; Thuma, Philip E.; Wright, David W.

    2018-01-01

    Abstract. A rapid, on-bead enzyme-linked immunosorbent assay for Plasmodium lactate dehydrogenase (pLDH) and Plasmodium falciparum histidine-rich protein 2 (HRP2) was adapted for use with dried blood spot (DBS) samples. This assay detected both biomarkers from a single DBS sample with only 45 minutes of total incubation time and detection limits of 600 ± 500 pM (pLDH) and 69 ± 30 pM (HRP2), corresponding to 150 and 24 parasites/μL, respectively. This sensitive and reproducible on-bead detection method was used to quantify pLDH and HRP2 in patient DBS samples from rural Zambia collected at multiple time points after treatment. Biomarker clearance patterns relative to parasite clearance were determined; pLDH clearance followed closely with parasite clearance, whereas most patients maintained detectable levels of HRP2 for 35–52 days after treatment. Furthermore, weak-to-moderate correlations between biomarker concentration and parasite densities were found for both biomarkers. This work demonstrates the utility of the developed assay for epidemiological study and surveillance of malaria. PMID:29557342

  18. Carbon Flux Trapping: Highly Efficient Production of Polymer-Grade d-Lactic Acid with a Thermophilic d-Lactate Dehydrogenase.

    PubMed

    Li, Chao; Tao, Fei; Xu, Ping

    2016-08-17

    High production of polymer-grade d-lactic acid is urgently required, particularly for the synthesis of polylactic acid. High-temperature fermentation has multiple advantages, such as lower equipment requirement and energy consumption, which are essential for lowering operating costs. We identified and introduced a unique d-lactate dehydrogenase into a thermotolerant butane-2,3-diol-producing strain. Carbon flux "trapping" was achieved by a "trapping point" created by combination of the introduced enzyme and the host efflux pump, which afforded irreversible transport of d-lactic acid. The overall carbon flux of the engineered strain was significantly enhanced and was redistributed predominantly to d-lactic acid. Under optimized conditions at 50 °C, d-lactic acid reached the highest titer (226.6 g L(-1) ) reported to date. This discovery allows us to extend the carbon flux trapping strategy to engineering complex metabolic networks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Global sequence diversity of the lactate dehydrogenase gene in Plasmodium falciparum.

    PubMed

    Simpalipan, Phumin; Pattaradilokrat, Sittiporn; Harnyuttanakorn, Pongchai

    2018-01-09

    Antigen-detecting rapid diagnostic tests (RDTs) have been recommended by the World Health Organization for use in remote areas to improve malaria case management. Lactate dehydrogenase (LDH) of Plasmodium falciparum is one of the main parasite antigens employed by various commercial RDTs. It has been hypothesized that the poor detection of LDH-based RDTs is attributed in part to the sequence diversity of the gene. To test this, the present study aimed to investigate the genetic diversity of the P. falciparum ldh gene in Thailand and to construct the map of LDH sequence diversity in P. falciparum populations worldwide. The ldh gene was sequenced for 50 P. falciparum isolates in Thailand and compared with hundreds of sequences from P. falciparum populations worldwide. Several indices of molecular variation were calculated, including the proportion of polymorphic sites, the average nucleotide diversity index (π), and the haplotype diversity index (H). Tests of positive selection and neutrality tests were performed to determine signatures of natural selection on the gene. Mean genetic distance within and between species of Plasmodium ldh was analysed to infer evolutionary relationships. Nucleotide sequences of P. falciparum ldh could be classified into 9 alleles, encoding 5 isoforms of LDH. L1a was the most common allelic type and was distributed in P. falciparum populations worldwide. Plasmodium falciparum ldh sequences were highly conserved, with haplotype and nucleotide diversity values of 0.203 and 0.0004, respectively. The extremely low genetic diversity was maintained by purifying selection, likely due to functional constraints. Phylogenetic analysis inferred the close genetic relationship of P. falciparum to malaria parasites of great apes, rather than to other human malaria parasites. This study revealed the global genetic variation of the ldh gene in P. falciparum, providing knowledge for improving detection of LDH-based RDTs and supporting the candidacy of

  20. Expression, purification, crystallization and preliminary X-ray crystallographic analysis of L-lactate dehydrogenase and its H171C mutant from Bacillus subtilis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Yanfeng; Gao, Xiaoli

    2012-08-31

    L-Lactate dehydrogenase (LDH) is an important enzyme involved in the last step of glycolysis that catalyzes the reversible conversion of pyruvate to L-lactate with the simultaneous oxidation of NADH to NAD{sup +}. In this study, wild-type LDH from Bacillus subtilis (BsLDH-WT) and the H171C mutant (BsLDH-H171C) were expressed in Escherichia coli and purified to near-homogeneity. BsLDH-WT was crystallized in the presence of fructose 1,6-bisphosphate (FBP) and NAD{sup +} and the crystal diffracted to 2.38 {angstrom} resolution. The crystal belonged to space group P3, with unit-cell parameters a = b = 171.04, c = 96.27 {angstrom}. BsLDH-H171C was also crystallized asmore » the apoenzyme and in complex with NAD{sup +}, and data sets were collected to 2.20 and 2.49 {angstrom} resolution, respectively. Both BsLDH-H171C crystals belonged to space group P3, with unit-cell parameters a = b = 133.41, c = 99.34 {angstrom} and a = b = 133.43, c = 99.09 {angstrom}, respectively. Tetramers were observed in the asymmetric units of all three crystals.« less

  1. INACTIVATION OF LACTATE DEHYDROGENASE BY SEVERAL CHEMICALS: IMPLICATIONS FOR IN VITRO TOXICOLOGY STUDIES

    PubMed Central

    Kendig, Derek M.; Tarloff, Joan B.

    2007-01-01

    Lactate dehydrogenase (LDH) release is frequently used as an end-point for cytotoxicity studies. We have been unable to measure LDH release during studies using para-aminophenol (PAP) in LLC-PK1 cells. When LLC-PK1 cells were incubated with either PAP (0–10 mM) or menadione (0–1000 μM), viability was markedly reduced when assessed by alamar Blue or total LDH activity but not by release of LDH into the incubation medium. In addition, we incubated cells with PAP or menadione and compared LDH activity using two different assays. Both assays confirmed our observation of decreased LDH activity in cell lysates without corresponding increases in LDH activity in incubation media. Using purified LDH and 10 mM PAP, we that PAP produced loss of LDH activity that was inversely proportional to the amount of LDH initially added. In additional experiments, we incubated 0.5 units of LDH for 1 h with varying concentrations of PAP, menadione, hydrogen peroxide (H2O2) or cisplatin. All four chemicals produced concentration-dependent decreases in LDH activity. In previous experiments, inclusion of antioxidants such as reduced glutathione (GSH) and ascorbate protected cells from PAP toxicity. GSH (1 mM) preserved LDH activity in the presence of toxicants while ascorbate (1 mM) only prevented LDH loss induced by PAP. These studies suggest that LDH that is released into the incubation medium is susceptible to degradation when reactive chemicals are present. PMID:17079110

  2. Activity of select dehydrogenases with sepharose-immobilized N(6)-carboxymethyl-NAD.

    PubMed

    Beauchamp, Justin; Vieille, Claire

    2015-01-01

    N(6)-carboxymethyl-NAD (N(6)-CM-NAD) can be used to immobilize NAD onto a substrate containing terminal primary amines. We previously immobilized N(6)-CM-NAD onto sepharose beads and showed that Thermotoga maritima glycerol dehydrogenase could use the immobilized cofactor with cofactor recycling. We now show that Saccharomyces cerevisiae alcohol dehydrogenase, rabbit muscle L-lactate dehydrogenase (type XI), bovine liver L-glutamic dehydrogenase (type III), Leuconostoc mesenteroides glucose-6-phosphate dehydro-genase, and Thermotoga maritima mannitol dehydrogenase are active with soluble N(6)-CM-NAD. The products of all enzymes but 6-phospho-D-glucono-1,5-lactone were formed when sepharose-immobilized N(6)-CM-NAD was recycled by T. maritima glycerol dehydrogenase, indicating that N(6)-immobilized NAD is suitable for use by a variety of different dehydrogenases. Observations of the enzyme active sites suggest that steric hindrance plays a greater role in limiting or allowing activity with the modified cofactor than do polarity and charge of the residues surrounding the N(6)-amine group on NAD.

  3. Highly elevated serum lactate dehydrogenase is associated with central nervous system relapse in patients with diffuse large B-cell lymphoma: Results of a multicenter prospective cohort study.

    PubMed

    Kim, Seok Jin; Hong, Jun Sik; Chang, Myung Hee; Kim, Jeong-A; Kwak, Jae-Yong; Kim, Jin Seok; Yoon, Dok Hyun; Lee, Won Sik; Do, Young Rok; Kang, Hye Jin; Eom, Hyeon-Seok; Park, Yong; Won, Jong-Ho; Mun, Yeung-Chul; Kim, Hyo Jung; Kwon, Jung Hye; Kong, Jee Hyun; Oh, Sung Yong; Lee, Sunah; Bae, Sung Hwa; Yang, Deok-Hwan; Jun, Hyun Jung; Kim, Yang Soo; Yun, Hwan Jung; Lee, Soon Il; Kim, Min Kyoung; Park, Eun Kyung; Kim, Won Seog; Suh, Cheolwon

    2016-11-01

    Central nervous system involvement remains a challenging issue in the treatment of patients with diffuse large B-cell lymphoma. We conducted a prospective cohort study with newly diagnosed diffuse large B-cell lymphoma patients receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone to identify incidence and risk factors for central nervous system involvement. Among 595 patients, 279 patients received pre-treatment central nervous system evaluation, and 14 patients had central nervous system involvement at diagnosis (2.3% out of entire patients and 5.0% out of the 279 patients). For those patients, median follow-up duration was 38.2 months and some of them achieved long-term survival. Out of 581 patients who did not have central nervous system involvement at diagnosis, 26 patients underwent secondary central nervous system relapse with a median follow-up of 35 months, and the median time to central nervous system involvement was 10.4 months (range: 3.4-29.2). Serum lactate dehydrogenase > ×3 upper limit of normal range, the Eastern Cooperative Oncology Group performance status ≥ 2, and involvement of sinonasal tract or testis, were independent risk factors for central nervous system relapse in multivariate analysis. Our study suggests that enhanced stratification of serum lactate dehydrogenase according to the National Comprehensive Cancer Network-International Prognostic Index may contribute to better prediction for central nervous system relapse in patients with diffuse large B-cell lymphoma. This trial was registered at clinicaltrials.gov identifier: 01202448.

  4. Highly elevated serum lactate dehydrogenase is associated with central nervous system relapse in patients with diffuse large B-cell lymphoma: Results of a multicenter prospective cohort study

    PubMed Central

    Kim, Seok Jin; Hong, Jun Sik; Chang, Myung Hee; Kim, Jeong-A; Kwak, Jae-Yong; Kim, Jin Seok; Yoon, Dok Hyun; Lee, Won Sik; Do, Young Rok; Kang, Hye Jin; Eom, Hyeon-Seok; Park, Yong; Won, Jong-Ho; Mun, Yeung-Chul; Kim, Hyo Jung; Kwon, Jung Hye; Kong, Jee Hyun; Oh, Sung Yong; Lee, Sunah; Bae, Sung Hwa; Yang, Deok-Hwan; Jun, Hyun Jung; Kim, Yang Soo; Yun, Hwan Jung; Il Lee, Soon; Kim, Min Kyoung; Park, Eun Kyung; Kim, Won Seog; Suh, Cheolwon

    2016-01-01

    Central nervous system involvement remains a challenging issue in the treatment of patients with diffuse large B-cell lymphoma. We conducted a prospective cohort study with newly diagnosed diffuse large B-cell lymphoma patients receiving rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone to identify incidence and risk factors for central nervous system involvement. Among 595 patients, 279 patients received pre-treatment central nervous system evaluation, and 14 patients had central nervous system involvement at diagnosis (2.3% out of entire patients and 5.0% out of the 279 patients). For those patients, median follow-up duration was 38.2 months and some of them achieved long-term survival. Out of 581 patients who did not have central nervous system involvement at diagnosis, 26 patients underwent secondary central nervous system relapse with a median follow-up of 35 months, and the median time to central nervous system involvement was 10.4 months (range: 3.4–29.2). Serum lactate dehydrogenase > ×3 upper limit of normal range, the Eastern Cooperative Oncology Group performance status ≥ 2, and involvement of sinonasal tract or testis, were independent risk factors for central nervous system relapse in multivariate analysis. Our study suggests that enhanced stratification of serum lactate dehydrogenase according to the National Comprehensive Cancer Network-International Prognostic Index may contribute to better prediction for central nervous system relapse in patients with diffuse large B-cell lymphoma. This trial was registered at clinicaltrials.gov identifier: 01202448. PMID:27713132

  5. Minimizing the effects of oxygen interference on l-lactate sensors by a single amino acid mutation in Aerococcus viridansl-lactate oxidase.

    PubMed

    Hiraka, Kentaro; Kojima, Katsuhiro; Lin, Chi-En; Tsugawa, Wakako; Asano, Ryutaro; La Belle, Jeffrey T; Sode, Koji

    2018-04-30

    l-lactate biosensors employing l-lactate oxidase (LOx) have been developed mainly to measure l-lactate concentration for clinical diagnostics, sports medicine, and the food industry. Some l-lactate biosensors employ artificial electron mediators, but these can negatively impact the detection of l-lactate by competing with the primary electron acceptor: molecular oxygen. In this paper, a strategic approach to engineering an AvLOx that minimizes the effects of oxygen interference on sensor strips was reported. First, we predicted an oxygen access pathway in Aerococcus viridans LOx (AvLOx) based on its crystal structure. This was subsequently blocked by a bulky amino acid substitution. The resulting Ala96Leu mutant showed a drastic reduction in oxidase activity using molecular oxygen as the electron acceptor and a small increase in dehydrogenase activity employing an artificial electron acceptor. Secondly, the Ala96Leu mutant was immobilized on a screen-printed carbon electrode using glutaraldehyde cross-linking method. Amperometric analysis was performed with potassium ferricyanide as an electron mediator under argon or atmospheric conditions. Under argon condition, the response current increased linearly from 0.05 to 0.5mM l-lactate for both wild-type and Ala96Leu. However, under atmospheric conditions, the response of wild-type AvLOx electrode was suppressed by 9-12% due to oxygen interference. The Ala96Leu mutant maintained 56-69% of the response current at the same l-lactate level and minimized the relative bias error to -19% from -49% of wild-type. This study provided significant insight into the enzymatic reaction mechanism of AvLOx and presented a novel approach to minimize oxygen interference in sensor applications, which will enable accurate detection of l-lactate concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Lactate dehydrogenase isoenzyme patterns upon chronic exposure to cigarette smoke: Protective effect of bacoside A.

    PubMed

    Anbarasi, Kothandapani; Sabitha, Kuruvimalai Ekambaram; Devi, Chennam Srinivasulu Shyamala

    2005-09-01

    Despite a strong association between cigarette smoking and alarming increase in mortality rate from smoking-related diseases, around 35-40% of the world's population continues to smoke and many more are being exposed to environmental tobacco smoke. Since the role of free radicals and oxidative damage in the pathogenesis of smoking-related diseases has been suggested, bacoside A, a potent antioxidant was tested for its ability to protect against cigarette smoking-induced toxicity in terms of lactate dehydrogenase (LDH) and its isoenzymes. Rats were exposed to cigarette smoke and simultaneously administered with bacoside A, for a period of 12 weeks. Total LDH activity was assayed in serum, lung, heart, brain, liver and kidney, and serum LDH isoforms were separated electrophoretically. Cigarette smoke exposure resulted in significant increase in serum LDH and its isoenzymes with a concomitant decrease in these organs. These alterations were prevented by administration of bacoside A. Excessive oxidants from cigarette smoke is known to cause peroxidation of membrane lipids leading to cellular damage, thereby resulting in the leakage of LDH into the circulation. Bacoside A could have rendered protection to the organs by stabilizing their cell membranes and prevented the release of LDH, probably through its free radical scavenging and anti-lipid peroxidative effect.

  7. Oxygen-Inducible Conversion of Lactate to Acetate in Heterofermentative Lactobacillus brevis ATCC 367.

    PubMed

    Guo, Tingting; Zhang, Li; Xin, Yongping; Xu, ZhenShang; He, Huiying; Kong, Jian

    2017-11-01

    Lactobacillus brevis is an obligatory heterofermentative lactic acid bacterium that produces high levels of acetate, which improve the aerobic stability of silages against deterioration caused by yeasts and molds. However, the mechanism involved in acetate accumulation has yet to be elucidated. Here, experimental evidence indicated that aerobiosis resulted in the conversion of lactate to acetate after glucose exhaustion in L. brevis ATCC 367 (GenBank accession number NC_008497). To elucidate the conversion pathway, in silico analysis showed that lactate was first converted to pyruvate by the reverse catalytic reaction of lactate dehydrogenase (LDH); subsequently, pyruvate conversion to acetate might be mediated by pyruvate dehydrogenase (PDH) or pyruvate oxidase (POX). Transcriptional analysis indicated that the pdh and pox genes of L. brevis ATCC 367 were upregulated 37.92- and 18.32-fold, respectively, by oxygen and glucose exhaustion, corresponding to 5.32- and 2.35-fold increases in the respective enzyme activities. Compared with the wild-type strain, the transcription and enzymatic activity of PDH remained stable in the Δ pox mutant, while those of POX increased significantly in the Δ pdh mutant. More lactate but less acetate was produced in the Δ pdh mutant than in the wild-type and Δ pox mutant strains, and more H 2 O 2 (a product of the POX pathway) was produced in the Δ pdh mutant. We speculated that the high levels of aerobic acetate accumulation in L. brevis ATCC 367 originated mainly from the reuse of lactate to produce pyruvate, which was further converted to acetate by the predominant and secondary functions of PDH and POX, respectively. IMPORTANCE PDH and POX are two possible key enzymes involved in aerobic acetate accumulation in lactic acid bacteria (LAB). It is currently thought that POX plays the major role in aerobic growth in homofermentative LAB and some heterofermentative LAB, while the impact of PDH remains unclear. In this study, we

  8. Oxygen-Inducible Conversion of Lactate to Acetate in Heterofermentative Lactobacillus brevis ATCC 367

    PubMed Central

    Guo, Tingting; Zhang, Li; Xin, Yongping; Xu, ZhenShang; He, Huiying

    2017-01-01

    ABSTRACT Lactobacillus brevis is an obligatory heterofermentative lactic acid bacterium that produces high levels of acetate, which improve the aerobic stability of silages against deterioration caused by yeasts and molds. However, the mechanism involved in acetate accumulation has yet to be elucidated. Here, experimental evidence indicated that aerobiosis resulted in the conversion of lactate to acetate after glucose exhaustion in L. brevis ATCC 367 (GenBank accession number NC_008497). To elucidate the conversion pathway, in silico analysis showed that lactate was first converted to pyruvate by the reverse catalytic reaction of lactate dehydrogenase (LDH); subsequently, pyruvate conversion to acetate might be mediated by pyruvate dehydrogenase (PDH) or pyruvate oxidase (POX). Transcriptional analysis indicated that the pdh and pox genes of L. brevis ATCC 367 were upregulated 37.92- and 18.32-fold, respectively, by oxygen and glucose exhaustion, corresponding to 5.32- and 2.35-fold increases in the respective enzyme activities. Compared with the wild-type strain, the transcription and enzymatic activity of PDH remained stable in the Δpox mutant, while those of POX increased significantly in the Δpdh mutant. More lactate but less acetate was produced in the Δpdh mutant than in the wild-type and Δpox mutant strains, and more H2O2 (a product of the POX pathway) was produced in the Δpdh mutant. We speculated that the high levels of aerobic acetate accumulation in L. brevis ATCC 367 originated mainly from the reuse of lactate to produce pyruvate, which was further converted to acetate by the predominant and secondary functions of PDH and POX, respectively. IMPORTANCE PDH and POX are two possible key enzymes involved in aerobic acetate accumulation in lactic acid bacteria (LAB). It is currently thought that POX plays the major role in aerobic growth in homofermentative LAB and some heterofermentative LAB, while the impact of PDH remains unclear. In this study, we

  9. Regulation of the Activity of Lactate Dehydrogenases from Four Lactic Acid Bacteria*

    PubMed Central

    Feldman-Salit, Anna; Hering, Silvio; Messiha, Hanan L.; Veith, Nadine; Cojocaru, Vlad; Sieg, Antje; Westerhoff, Hans V.; Kreikemeyer, Bernd; Wade, Rebecca C.; Fiedler, Tomas

    2013-01-01

    Despite high similarity in sequence and catalytic properties, the l-lactate dehydrogenases (LDHs) in lactic acid bacteria (LAB) display differences in their regulation that may arise from their adaptation to different habitats. We combined experimental and computational approaches to investigate the effects of fructose 1,6-bisphosphate (FBP), phosphate (Pi), and ionic strength (NaCl concentration) on six LDHs from four LABs studied at pH 6 and pH 7. We found that 1) the extent of activation by FBP (Kact) differs. Lactobacillus plantarum LDH is not regulated by FBP, but the other LDHs are activated with increasing sensitivity in the following order: Enterococcus faecalis LDH2 ≤ Lactococcus lactis LDH2 < E. faecalis LDH1 < L. lactis LDH1 ≤ Streptococcus pyogenes LDH. This trend reflects the electrostatic properties in the allosteric binding site of the LDH enzymes. 2) For L. plantarum, S. pyogenes, and E. faecalis, the effects of Pi are distinguishable from the effect of changing ionic strength by adding NaCl. 3) Addition of Pi inhibits E. faecalis LDH2, whereas in the absence of FBP, Pi is an activator of S. pyogenes LDH, E. faecalis LDH1, and L. lactis LDH1 and LDH2 at pH 6. These effects can be interpreted by considering the computed binding affinities of Pi to the catalytic and allosteric binding sites of the enzymes modeled in protonation states corresponding to pH 6 and pH 7. Overall, the results show a subtle interplay among the effects of Pi, FBP, and pH that results in different regulatory effects on the LDHs of different LABs. PMID:23720742

  10. Investigation of Risk Factors Affecting Lactate Levels in Japanese Patients Treated with Metformin.

    PubMed

    Yokoyama, Shota; Tsuji, Hideyuki; Hiraoka, Sachiko; Nishihara, Masayuki

    2016-01-01

    Metformin is a biguanaide antidiabetic drug used worldwide, and its effectiveness and benefits have already been established. However, the safety of high doses of metformin in Japanese patients, especially in elderly patients with a decreased renal function, remains unclear. Among the side effects of metformin, lactate acidosis is the most problematic due to a high mortality rate. Therefore, we assessed plasma lactate levels in metformin-treated patients to identify independent risk factors for hyperlactemia. 290 outpatients receiving various doses of metformin at our hospital were enrolled between March and July 2014. Serum electrolytes, Cre (creatinine), BUN (blood urea nitrogen), UA (uric acid), HbA1c (hemoglobin A1c), and lactate levels were investigated. Lactate levels did not significantly differ between the elderly (≥75 years) and non-elderly (<75 years) groups. Patients in the elderly group had a significantly lower daily metformin dose and estimated glomerular filtration rate (eGFR), compared with the non-elderly group (both p<0.005). Between with and without hyperlactemia groups, no significant differences were observed in either Cre or age. On the other hand, patients with hyperlactemia had a significantly higher dose of metformin than those without hyperlactemia (p<0.05). In this study, we found that old age and mildly impaired kidney function were not associated with increased lactate levels, and that a higher dose of metformin may be an independent risk factor for elevated lactate levels in Japanese patients.

  11. Impact of critical process and formulation parameters affecting in-process stability of lactate dehydrogenase during the secondary drying stage of lyophilization: a mini freeze dryer study.

    PubMed

    Luthra, Sumit; Obert, Jean-Philippe; Kalonia, Devendra S; Pikal, Michael J

    2007-09-01

    The stresses during the secondary-drying stage of lyophilization were investigated using a controlled humidity mini-freeze-dryer [Luthra S, Obert J-P, Kalonia DS, Pikal MJ. 2007. Investigation of drying stresses on proteins during lyophilization: Differentiation between primary and secondary-drying stresses on lactate dehydrogenase using a humidity controlled mini freeze-dryer. J Pharm Sci 96: 61-70.]. Lactate dehydrogenase (LDH), was formulated in: (1) Tween 80, (2) citrate buffer, and (3) both Tween 80 and citrate buffer. Protein activity recovery was measured as a function of relative humidity (RH), product temperature, and drying duration. Studies were also conducted with different concentrations of sucrose, sorbitol, and poly (vinyl pyrrolidone) (PVP). LDH stability was affected to a small extent by RH and significantly by drying temperature and duration. Complete stabilization of LDH was observed when lyophilized with sucrose and PVP but only a partial stabilization was observed with sorbitol. The mini-freeze-dryer enabled studying the process parameters independently, unlike a conventional study where these effects are generally convoluted. The results suggest that the stability of the protein is a function of the dynamics of the system during lyophilization. The origin of the stabilization effect of sucrose, which could, in principle, be attributed both to direct interaction with the protein or vitrification of the protein was elucidated using lyoprotectants that can either hydrogen bond well with the protein (sorbitol) or form a good glass (PVP). It appears both effects are required for complete stabilization of the protein. (c) 2007 Wiley-Liss, Inc. and the American Pharmacists Association.

  12. Saccharomyces cerevisiae Forms d-2-Hydroxyglutarate and Couples Its Degradation to d-Lactate Formation via a Cytosolic Transhydrogenase*♦

    PubMed Central

    Becker-Kettern, Julia; Paczia, Nicole; Conrotte, Jean-François; Kay, Daniel P.; Guignard, Cédric; Jung, Paul P.; Linster, Carole L.

    2016-01-01

    The d or l form of 2-hydroxyglutarate (2HG) accumulates in certain rare neurometabolic disorders, and high d-2-hydroxyglutarate (d-2HG) levels are also found in several types of cancer. Although 2HG has been detected in Saccharomyces cerevisiae, its metabolism in yeast has remained largely unexplored. Here, we show that S. cerevisiae actively forms the d enantiomer of 2HG. Accordingly, the S. cerevisiae genome encodes two homologs of the human d-2HG dehydrogenase: Dld2, which, as its human homolog, is a mitochondrial protein, and the cytosolic protein Dld3. Intriguingly, we found that a dld3Δ knock-out strain accumulates millimolar levels of d-2HG, whereas a dld2Δ knock-out strain displayed only very moderate increases in d-2HG. Recombinant Dld2 and Dld3, both currently annotated as d-lactate dehydrogenases, efficiently oxidized d-2HG to α-ketoglutarate. Depletion of d-lactate levels in the dld3Δ, but not in the dld2Δ mutant, led to the discovery of a new type of enzymatic activity, carried by Dld3, to convert d-2HG to α-ketoglutarate, namely an FAD-dependent transhydrogenase activity using pyruvate as a hydrogen acceptor. We also provide evidence that Ser3 and Ser33, which are primarily known for oxidizing 3-phosphoglycerate in the main serine biosynthesis pathway, in addition reduce α-ketoglutarate to d-2HG using NADH and represent major intracellular sources of d-2HG in yeast. Based on our observations, we propose that d-2HG is mainly formed and degraded in the cytosol of S. cerevisiae cells in a process that couples d-2HG metabolism to the shuttling of reducing equivalents from cytosolic NADH to the mitochondrial respiratory chain via the d-lactate dehydrogenase Dld1. PMID:26774271

  13. Phosphorylation status of pyruvate dehydrogenase distinguishes metabolic phenotypes of cultured rat brain astrocytes and neurons.

    PubMed

    Halim, Nader D; Mcfate, Thomas; Mohyeldin, Ahmed; Okagaki, Peter; Korotchkina, Lioubov G; Patel, Mulchand S; Jeoung, Nam Ho; Harris, Robert A; Schell, Michael J; Verma, Ajay

    2010-08-01

    Glucose metabolism in nervous tissue has been proposed to occur in a compartmentalized manner with astrocytes contributing largely to glycolysis and neurons being the primary site of glucose oxidation. However, mammalian astrocytes and neurons both contain mitochondria, and it remains unclear why in culture neurons oxidize glucose, lactate, and pyruvate to a much larger extent than astrocytes. The objective of this study was to determine whether pyruvate metabolism is differentially regulated in cultured neurons versus astrocytes. Expression of all components of the pyruvate dehydrogenase complex (PDC), the rate-limiting step for pyruvate entry into the Krebs cycle, was determined in cultured astrocytes and neurons. In addition, regulation of PDC enzymatic activity in the two cell types via protein phosphorylation was examined. We show that all components of the PDC are expressed in both cell types in culture, but that PDC activity is kept strongly inhibited in astrocytes through phosphorylation of the pyruvate dehydrogenase alpha subunit (PDH alpha). In contrast, neuronal PDC operates close to maximal levels with much lower levels of phosphorylated PDH alpha. Dephosphorylation of astrocytic PDH alpha restores PDC activity and lowers lactate production. Our findings suggest that the glucose metabolism of astrocytes and neurons may be far more flexible than previously believed. (c) 2010 Wiley-Liss, Inc.

  14. Type II flavohemoglobin of Mycobacterium smegmatis oxidizes d-lactate and mediate electron transfer.

    PubMed

    Thakur, Naveen; Kumar, Ashwani; Dikshit, Kanak L

    2018-06-01

    Two distantly related flavohemoglobins (FHbs), MsFHbI and MsFHbII, having crucial differences in their heme and reductase domains, co-exist in Mycobacterium smegmatis. Function of MsFHbI is associated with nitric-oxide detoxification but physiological relevance of MsFHbII remains unknown. This study unravels some unique spectral and functional characteristics of MsFHbII. Unlike conventional type I FHbs, MsFHbII lacks nitric-oxide dioxygenase and NADH oxidase activities but utilizes d-lactate as an electron donor to mediate electron transfer. MsFHbII carries a d-lactate dehydrogenase type FAD binding motif in its reductase domain and oxidizes d-lactate in a FAD dependent manner to reduce the heme iron, suggesting that the globin is acting as an electron acceptor. Importantly, expression of MsFHbII in Escherichia coli imparted protection under oxidative stress, suggesting its important role in stress management of its host. Since M. smegmatis lacks the gene encoding for d-lactate dehydrogenase and d-lactate is produced during aerobic metabolism and also as a by-product of lipid peroxidation, the ability of MsFHbII to metabolize d-lactate may provide it a unique ability to balance the oxidative stress generated due to accumulation of d-lactate in the cell and at the same time sequester electrons and pass it to the respiratory apparatus. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Dorsal Anterior Cingulate Lactate and Glutathione Levels in Euthymic Bipolar I Disorder: 1H-MRS Study.

    PubMed

    Soeiro-de-Souza, Márcio Gerhardt; Pastorello, Bruno F; Leite, Cláudia da Costa; Henning, Anke; Moreno, Ricardo A; Garcia Otaduy, Maria Concepción

    2016-08-01

    Oxidative stress and mitochondrial dysfunction are 2 closely integrated processes implicated in the physiopathology of bipolar disorder. Advanced proton magnetic resonance spectroscopy techniques enable the measurement of levels of lactate, the main marker of mitochondrial dysfunction, and glutathione, the predominant brain antioxidant. The objective of this study was to measure brain lactate and glutathione levels in bipolar disorder and healthy controls. Eighty-eight individuals (50 bipolar disorder and 38 healthy controls) underwent 3T proton magnetic resonance spectroscopy in the dorsal anterior cingulate cortex (2x2x4.5cm(3)) using a 2-D JPRESS sequence. Lactate and glutathione were quantified using the ProFit software program. Bipolar disorder patients had higher dorsal anterior cingulate cortex lactate levels compared with controls. Glutathione levels did not differ between euthymic bipolar disorder and controls. There was a positive correlation between lactate and glutathione levels specific to bipolar disorder. No influence of medications on metabolites was observed. This is the most extensive magnetic resonance spectroscopy study of lactate and glutathione in bipolar disorder to date, and results indicated that euthymic bipolar disorder patients had higher levels of lactate, which might be an indication of altered mitochondrial function. Moreover, lactate levels correlated with glutathione levels, indicating a compensatory mechanism regardless of bipolar disorder diagnosis. © The Author 2016. Published by Oxford University Press on behalf of CINP.

  16. Dorsal Anterior Cingulate Lactate and Glutathione Levels in Euthymic Bipolar I Disorder: 1H-MRS Study

    PubMed Central

    Pastorello, Bruno F.; Leite, Cláudia da Costa; Henning, Anke; Moreno, Ricardo A.; Garcia Otaduy, Maria Concepción

    2016-01-01

    Objective: Oxidative stress and mitochondrial dysfunction are 2 closely integrated processes implicated in the physiopathology of bipolar disorder. Advanced proton magnetic resonance spectroscopy techniques enable the measurement of levels of lactate, the main marker of mitochondrial dysfunction, and glutathione, the predominant brain antioxidant. The objective of this study was to measure brain lactate and glutathione levels in bipolar disorder and healthy controls. Methods: Eighty-eight individuals (50 bipolar disorder and 38 healthy controls) underwent 3T proton magnetic resonance spectroscopy in the dorsal anterior cingulate cortex (2x2x4.5cm3) using a 2-D JPRESS sequence. Lactate and glutathione were quantified using the ProFit software program. Results: Bipolar disorder patients had higher dorsal anterior cingulate cortex lactate levels compared with controls. Glutathione levels did not differ between euthymic bipolar disorder and controls. There was a positive correlation between lactate and glutathione levels specific to bipolar disorder. No influence of medications on metabolites was observed. Conclusion: This is the most extensive magnetic resonance spectroscopy study of lactate and glutathione in bipolar disorder to date, and results indicated that euthymic bipolar disorder patients had higher levels of lactate, which might be an indication of altered mitochondrial function. Moreover, lactate levels correlated with glutathione levels, indicating a compensatory mechanism regardless of bipolar disorder diagnosis. PMID:27207914

  17. Structure and Function of Plasmodium falciparum malate dehydrogenase: Role of Critical Amino Acids in C-substrate Binding Procket

    USDA-ARS?s Scientific Manuscript database

    Malaria parasite thrives on anaerobic fermentation of glucose for energy. Earlier studies from our lab have demonstrated that a cytosolic malate dehydrogenase (PfMDH) with striking similarity to lactate dehydrogenase (PfLDH) might complement PfLDH function in Plasmodium falciparum. The N-terminal g...

  18. Elevated levels of liver methylglyoxal and d-lactate in early-stage hepatitis in rats.

    PubMed

    Wang, Wen-Chuang; Chou, Chu-Kuang; Chuang, Ming-Cheng; Li, Yi-Chieh; Lee, Jen-Ai

    2018-02-01

    Methylglyoxal (MGO) is highly cytotoxic and its levels are elevated in diabetes, nephropathy and atherosclerosis. However, it has never been studied in liver disease. For this reason, we aimed to assess the levels of MGO and its metabolite d-lactate in an early hepatitis model. Wistar rats were administered CCl 4 (0.75 mL/kg, i.p.) to induce hepatitis. In either CCl 4 -treated or untreated rats, alanine transaminase and aspartate transaminase levels did not change over the course of the study, indicating that significant liver damage did not occur following CCl 4 treatment. However, the levels of MGO and d-lactate were higher in the livers of CCl 4 -treated animals than in untreated animals (MGO: 128.2 ± 18.8 and 248.1 ± 64.9 μg/g protein, p < 0.01; d-lactate: 0.860 ± 0.040 and 1.293 ± 0.078 μmol/g protein, respectively p < 0.01). Furthermore, in untreated and treated animals, serum d-lactate levels were 57.65 ± 2.59 and 92.16 ± 16.69 μm and urine d-lactate levels were 1.060 ± 0.007 and 1.555 ± 0.366 μmol/mg UCr, respectively (p < 0.01). These data show that in this model of early-stage liver damage, the levels of MGO and its metabolite d-lactate are elevated and that d-lactate could be useful as a reference marker for the early stage of hepatitis. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

    PubMed

    Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

    2014-09-01

    Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (p<0.05). Aging also reduced LDH-A mRNA abundance, however there was no age effect on LDH-B mRNA abundance. In 5-month muscle, both ND and OV decreased LDH-A and LDH-B activity. However, there was no synergistic or additive effect. In 5-month muscle, ND and OV decreased LDH-A mRNA expression with no change in LDH-B expression. In 25-month muscle, ND and OV increased LDH-A and LDH-B activity. LDH-A mRNA expression was not altered by ND or OV in aged muscle. However, there was a main effect of OV to decrease LDH-B mRNA expression. There was also an age-induced LDH isoform shift. ND and OV treatment increased the "fast" LDH isoforms in aged muscle, whereas ND and OV increased the "slow" isoforms in young muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid

  20. CSF lactate level: a useful diagnostic tool to differentiate acute bacterial and viral meningitis.

    PubMed

    Abro, Ali Hassan; Abdou, Ahmed Saheh; Ustadi, Abdulla M; Saleh, Ahmed Alhaj; Younis, Nadeem Javeed; Doleh, Wafa F

    2009-08-01

    To evaluate the potential role of CSF lactate level in the diagnosis of acute bacterial meningitis and in the differentiation between viral and bacterial meningitis. This was a hospital based observational study, conducted at Infectious Diseases Unit, Rashid Hospital Dubai, United Arab Emirates, from July 2004 to June 2007. The patients with clinical diagnosis of acute bacterial meningitis and who had CSF Gram stain/culture positive, CSF analysis suggestive of bacterial meningitis with negative Gram stain and culture but blood culture positive for bacteria and patients with clinical diagnosis suggestive of viral meningitis supported by CSF chemical analysis with negative Gram stain and culture as well as negative blood culture for bacteria were included in the study. CT scan brain was done for all patients before lumber puncture and CSF and blood samples were collected immediately after admission. CSF chemical analysis including lactate level was done on first spinal tap. The CSF lactate level was tested by Enzymatic Colorimetric method. A total 95 adult patients of acute meningitis (53 bacterial and 42 viral) fulfilled the inclusion criteria. Among 53 bacterial meningitis patients, Neisseria meningitides were isolated in 29 (54.7%), Strept. Pneumoniae in 18 (33.96%), Staph. Aureus in 2 (3.77%), Klebsiell Pneumoniae in 2 (3.77%), Strept. Agalactiae in 1 (1.8%) and E. Coli in 1 (1.8%). All the patients with bacterial meningitis had CSF lactate > 3.8 mmol/l except one, whereas none of the patients with viral meningitis had lactate level > 3.8 mmol/l. The mean CSF lactate level in bacterial meningitis cases amounted to 16.51 +/- 6.14 mmol/l, whereas it was significantly lower in viral group 2.36 +/- 0.6 mmol/l, p < .0001. CSF lactate level was significantly high in bacterial than viral meningitis and it can provide pertinent, rapid and reliable diagnostic information. Furthermore, CSF lactate level can also differentiate bacterial meningitis from viral one in a quick

  1. Urinary excretion levels of water-soluble vitamins in pregnant and lactating women in Japan.

    PubMed

    Shibata, Katsumi; Fukuwatari, Tsutomu; Sasaki, Satoshi; Sano, Mitsue; Suzuki, Kahoru; Hiratsuka, Chiaki; Aoki, Asami; Nagai, Chiharu

    2013-01-01

    Recent studies have shown that the urinary excretion levels of water-soluble vitamins can be used as biomarkers for the nutritional status of these vitamins. To determine changes in the urinary excretion levels of water-soluble vitamins during pregnant and lactating stages, we surveyed and compared levels of nine water-soluble vitamins in control (non-pregnant and non-lactating women), pregnant and lactating women. Control women (n=37), women in the 2nd (16-27 wk, n=24) and 3rd trimester of pregnancy (over 28 wk, n=32), and early- (0-5 mo, n=54) and late-stage lactating (6-11 mo, n=49) women took part in the survey. The mean age of subjects was ~30 y, and mean height was ~160 cm. A single 24-h urine sample was collected 1 d after the completion of a validated, self-administered comprehensive diet history questionnaire to measure water-soluble vitamins or metabolites. The average intake of each water-soluble vitamin was ≍ the estimated average requirement value and adequate intake for the Japanese Dietary Reference Intakes in all life stages, except for vitamin B6 and folate intakes during pregnancy. No change was observed in the urinary excretion levels of vitamin B2, vitamin B6, vitamin B12, biotin or vitamin C among stages. Urine nicotinamide and folate levels were higher in pregnant women than in control women. Urine excretion level of vitamin B1 decreased during lactation and that of pantothenic acid decreased during pregnancy and lactation. These results provide valuable information for setting the Dietary Reference Intakes of water-soluble vitamins for pregnant and lactating women.

  2. Effect of level of chronic immune system activation on the lactational performance of sows.

    PubMed

    Sauber, T E; Stahly, T S; Nonnecke, B J

    1999-08-01

    The effect of the level of chronic immune system (IS) activation on sow lactational performance was determined in 11 pairs of littermate, primiparous sows. Sows with a low level of IS activation were created by rearing the animals via early weaning, isolated rearing schemes. During lactation, two levels of IS activation were achieved in each littermate sow pair by subcutaneous administration of either 0 (saline) or 5 microg/kg of sow BW of Escherichia coli lipopolysaccharide (LPS) in a mineral oil adjuvant emulsion on d 2 and 10 of lactation. Litters were standardized to 13 pigs by 8 h postpartum. Sows were offered daily 6.0 kg of a corn-soy diet formulated to contain a minimum of 250% of the dietary nutrient concentrations estimated to be needed by lactating sows. Based on antibody titers to LPS and serum concentrations of alpha-1 acid glycoprotein (AGP), high IS sows mounted an immune response to the LPS during lactation, and low IS sows maintained a low level of IS activation. Over an 18-d lactation, a high level of chronic activation of the sows' immune systems depressed daily sow feed intakes by .56 kg, litter weight gains by .32 kg, and daily milk by 1.4 kg, milk energy by 1.7 Mcal, and milk protein yields by 71 g, but did not alter sow body weight loss. The reductions in yields of milk and milk nutrients likely were because of proinflammatory cytokine-induced inhibition of the lactogenic hormones resulting from high chronic IS activation. Based on these data, the level of chronic IS activation alters the lactational performance of sows.

  3. Improved production of homo-D-lactic acid via xylose fermentation by introduction of xylose assimilation genes and redirection of the phosphoketolase pathway to the pentose phosphate pathway in L-Lactate dehydrogenase gene-deficient Lactobacillus plantarum.

    PubMed

    Okano, Kenji; Yoshida, Shogo; Yamada, Ryosuke; Tanaka, Tsutomu; Ogino, Chiaki; Fukuda, Hideki; Kondo, Akihiko

    2009-12-01

    The production of optically pure d-lactic acid via xylose fermentation was achieved by using a Lactobacillus plantarum NCIMB 8826 strain whose l-lactate dehydrogenase gene was deficient and whose phosphoketolase genes were replaced with a heterologous transketolase gene. After 60 h of fermentation, 41.2 g/liter of d-lactic acid was produced from 50 g/liter of xylose.

  4. SYNAPTOSOMAL LACTATE DEHYDROGENASE ISOENZYME COMPOSITION IS SHIFTED TOWARD AEROBIC FORMS IN PRIMATE BRAIN EVOLUTION

    PubMed Central

    Duka, Tetyana; Anderson, Sarah M.; Collins, Zachary; Raghanti, Mary Ann; Ely, John J.; Hof, Patrick R.; Wildman, Derek E.; Goodman, Morris; Grossman, Lawrence I.; Sherwood, Chet C.

    2014-01-01

    With the evolution of a relatively large brain size in haplorhine primates (i.e., tarsiers, monkeys, apes and humans), there have been associated changes in the molecular machinery that delivers energy to the neocortex. Here we investigated variation in lactate dehydrogenase (LDH) expression and isoenzyme composition of the neocortex and striatum in primates using quantitative Western blotting and isoenzyme analysis of total homogenates and synaptosomal fractions. Analysis of isoform expression revealed that LDH in the synaptosomal fraction from both forebrain regions shifted towards a predominance of the heart-type, aerobic isoforms, LDHB, among haplorhines as compared to strepsirrhines (i.e., lorises and lemurs), while in total homogenate of neocortex and striatum there was no significant difference in the LDH isoenzyme composition between the primate suborders. The largest increase occurred in synapse-associated LDH-B expression in the neocortex, displaying an especially remarkable elevation in the ratio of LDH-B to LDH-A in humans. The phylogenetic variation in LDH-B to LDH-A ratio was correlated with species typical brain mass, but not encephalization quotient. A significant LDHB increase in the sub-neuronal fraction from haplorhine neocortex and striatum suggests a relatively higher rate of aerobic glycolysis that is linked to synaptosomal mitochondrial metabolism. Our results indicate that there is differential composition of LDH isoenzymes and metabolism in synaptic terminals that evolved in primates to meet increased energy requirements in association with brain enlargement. PMID:24686273

  5. Molecular cloning, characterization, and immunolocalization of two lactate dehydrogenase homologous genes from Taenia solium.

    PubMed

    Du, Wuying; Hu, Fengyu; Yang, Yabo; Hu, Dong; Hu, Xuchu; Yu, Xinbing; Xu, Jin; Dai, Jialin; Liao, Xinjiang; Huang, Jiang

    2011-09-01

    Two novel genes encoding lactate dehydrogenase A (LDHA) and B (LDHB) homologues, respectively, were identified from the cDNA libraries of adult Taenia solium (T. solium). The two deduced amino acid sequences both show more than 50% identity to the homologues for Danio rerio, Xenopus laevis, Schistosoma japonicum, Sus scrofa, Homo sapiens, et al. The identity of the amino acid sequence between TsLDHA and TsLDHB is 57.4%, and that of the nucleotide sequence is 61.5%. Recombinant TsLDHA homologue (rTsLDHA) and TsLDHB homologue (rTsLDHB) were expressed in Escherichia coli BL21/DE3 and purified. Though there were some differences in the sequence, the two LDH isozyme homologues show similarity in the conserved LDH domain, topological structure, primary immunological traits, localization on the tegument of T. solium adult, and partial physicochemical properties. The linear B-cell epitope analysis of TsLDHA and TsLDHB discovered a TsLDHA specific epitope. The purified rTsLDHA and rTsLDHB could be recognized by rat immuno-sera, serum from swine, or a patient infected with T. solium, respectively, but Western blot analysis showed cross-reactions, not only between these two LDH members but also with other common human tapeworms or helminths. The results suggested that the two LDH homologues are similar in the characteristics of LDH family, and they are not specific antigens for immunodiagnosis.

  6. Is there an association between body temperature and serum lactate levels in hip fracture patients?

    PubMed Central

    Murtuza, F; Farrier, AJ; Venkatesan, M; Smith, R; Khan, A; Uzoigwe, CE; Chami, G

    2015-01-01

    Introduction Hyperlactataemia is associated with adverse outcomes in trauma cases. It is thought to be the result of anaerobic respiration during hypoperfusion. This produces much less energy than complete aerobic glycolysis. Low body temperature in the injured patient carries an equally poor prognosis. Significant amounts of energy are expended in maintaining euthermia. Consequently, there may be a link between lactate levels and dysthermia. Hyperlactataemia may be indicative of inefficient energy production and therefore insufficient energy to maintain euthermia. Alternatively, significant amounts of available oxygen may be sequestered in thermoregulation, resulting in anaerobic respiration and lactate production. Our study investigated whether there is an association between lactate levels and admission body temperature in hip fracture patients. Furthermore, it looked at whether there is a difference in the mean lactate levels between hip fracture patients with low (<36.5°C), normal (36.5–37.5°C) and high (>37.5°C) body temperature on admission, and for patients who have low body temperature, whether there is a progressive rise in serum lactate levels as body temperature falls. Methods The admission temperature and serum lactate of 1,162 patients presenting with hip fracture were recorded. Patients were divided into the euthermic (body temperature 36.5–37.5°C), the pyrexial (>37.5°C) and those with low body temperature (<36.5°C). Admission lactate and body temperature were compared. Results There was a significant difference in age between the three body temperature groups (p=0.007). The pyrexial cohort was younger than the low body temperature group (mean: 78 vs 82 years). Those with low body temperature had a higher mean lactate level than the euthermic (2.2mmol/l vs 2.0mmol/l, p=0.03). However, there was no progressive rise in serum lactate level as admission temperature fell. Conclusions The findings suggest that in hip fracture patients, the body

  7. Is there an association between body temperature and serum lactate levels in hip fracture patients?

    PubMed

    Murtuza, F; Farrier, A J; Venkatesan, M; Smith, R; Khan, A; Uzoigwe, C E; Chami, G

    2015-10-01

    Introduction Hyperlactataemia is associated with adverse outcomes in trauma cases. It is thought to be the result of anaerobic respiration during hypoperfusion. This produces much less energy than complete aerobic glycolysis. Low body temperature in the injured patient carries an equally poor prognosis. Significant amounts of energy are expended in maintaining euthermia. Consequently, there may be a link between lactate levels and dysthermia. Hyperlactataemia may be indicative of inefficient energy production and therefore insufficient energy to maintain euthermia. Alternatively, significant amounts of available oxygen may be sequestered in thermoregulation, resulting in anaerobic respiration and lactate production. Our study investigated whether there is an association between lactate levels and admission body temperature in hip fracture patients. Furthermore, it looked at whether there is a difference in the mean lactate levels between hip fracture patients with low (<36.5°C), normal (36.5-37.5°C) and high (>37.5°C) body temperature on admission, and for patients who have low body temperature, whether there is a progressive rise in serum lactate levels as body temperature falls. Methods The admission temperature and serum lactate of 1,162 patients presenting with hip fracture were recorded. Patients were divided into the euthermic (body temperature 36.5-37.5°C), the pyrexial (>37.5°C) and those with low body temperature (<36.5°C). Admission lactate and body temperature were compared. Results There was a significant difference in age between the three body temperature groups (p=0.007). The pyrexial cohort was younger than the low body temperature group (mean: 78 vs 82 years). Those with low body temperature had a higher mean lactate level than the euthermic (2.2mmol/l vs 2.0mmol/l, p=0.03). However, there was no progressive rise in serum lactate level as admission temperature fell. Conclusions The findings suggest that in hip fracture patients, the body

  8. Lactate is oxidized outside of the mitochondrial matrix in rodent brain.

    PubMed

    Herbst, Eric A F; George, Mitchell A J; Brebner, Karen; Holloway, Graham P; Kane, Daniel A

    2018-05-01

    The nature and existence of mitochondrial lactate oxidation is debated in the literature. Obscuring the issue are disparate findings in isolated mitochondria, as well as relatively low rates of lactate oxidation observed in permeabilized muscle fibres. However, respiration with lactate has yet to be directly assessed in brain tissue with the mitochondrial reticulum intact. To determine if lactate is oxidized in the matrix of brain mitochondria, oxygen consumption was measured in saponin-permeabilized mouse brain cortex samples, and rat prefrontal cortex and hippocampus (dorsal) subregions. While respiration in the presence of ADP and malate increased with the addition of lactate, respiration was maximized following the addition of exogenous NAD + , suggesting maximal lactate metabolism involves extra-matrix lactate dehydrogenase. This was further supported when NAD + -dependent lactate oxidation was significantly decreased with the addition of either low-concentration α-cyano-4-hydroxycinnamate or UK-5099, inhibitors of mitochondrial pyruvate transport. Mitochondrial respiration was comparable between glutamate, pyruvate, and NAD + -dependent lactate oxidation. Results from the current study demonstrate that permeabilized brain is a feasible model for assessing lactate oxidation, and support the interpretation that lactate oxidation occurs outside the mitochondrial matrix in rodent brain.

  9. Cerebrospinal fluid lactate level as a diagnostic biomarker for bacterial meningitis in children

    PubMed Central

    2014-01-01

    Background Cerebrospinal fluid (CSF) lactate is a potential biomarker for bacterial meningitis in children. To this end, we performed a single-center retrospective cohort study of children from Sao Paulo, Brazil, with CSF pleocytosis to evaluate the ability of CSF lactate to distinguish between children with bacterial and aseptic meningitis. We determined the optimum cutoff point for CSF lactate using receiver-operator curve (ROC) analysis. Findings We identified 451 children of whom 40 (9%) had bacterial meningitis. Children with bacterial meningitis had a higher median CSF lactate level [9.6 mmol/l, interquartile range (IQR) 3.2-38.5 mmol/l bacterial meningitis vs. 2.0 mmol/l, IQR 1.2-2.8 mmol/l aseptic meningitis]. A CSF lactate cutoff point of 3.0 mmol/l had a sensitivity of 95% [95% confidence interval (CI) 83-99%), specificity of 94% (95% CI 90-96%) and negative predictive value of 99.3% (95% CI 97.7-99.9%) for bacterial meningitis. Conclusions In combination with a validated meningitis clinical prediction rule, the CSF lactate level can be used to distinguish between bacterial and aseptic meningitis in children with CSF pleocytosis. PMID:24576334

  10. Cerebrospinal fluid lactate level as a diagnostic biomarker for bacterial meningitis in children.

    PubMed

    Mekitarian Filho, Eduardo; Horita, Sérgio Massaru; Gilio, Alfredo Elias; Nigrovic, Lise E

    2014-02-27

    Cerebrospinal fluid (CSF) lactate is a potential biomarker for bacterial meningitis in children. To this end, we performed a single-center retrospective cohort study of children from Sao Paulo, Brazil, with CSF pleocytosis to evaluate the ability of CSF lactate to distinguish between children with bacterial and aseptic meningitis. We determined the optimum cutoff point for CSF lactate using receiver-operator curve (ROC) analysis. We identified 451 children of whom 40 (9%) had bacterial meningitis. Children with bacterial meningitis had a higher median CSF lactate level [9.6 mmol/l, interquartile range (IQR) 3.2-38.5 mmol/l bacterial meningitis vs. 2.0 mmol/l, IQR 1.2-2.8 mmol/l aseptic meningitis]. A CSF lactate cutoff point of 3.0 mmol/l had a sensitivity of 95% [95% confidence interval (CI) 83-99%), specificity of 94% (95% CI 90-96%) and negative predictive value of 99.3% (95% CI 97.7-99.9%) for bacterial meningitis. In combination with a validated meningitis clinical prediction rule, the CSF lactate level can be used to distinguish between bacterial and aseptic meningitis in children with CSF pleocytosis.

  11. Effects and Mechanism of Atmospheric-Pressure Dielectric Barrier Discharge Cold Plasma on Lactate Dehydrogenase (LDH) Enzyme

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Xu, Zimu; Shen, Jie; Li, Xu; Ding, Lili; Ma, Jie; Lan, Yan; Xia, Weidong; Cheng, Cheng; Sun, Qiang; Zhang, Zelong; Chu, Paul K.

    2015-05-01

    Proteins are carriers of biological functions and the effects of atmospheric-pressure non-thermal plasmas on proteins are important to applications such as sterilization and plasma-induced apoptosis of cancer cells. Herein, we report our detailed investigation of the effects of helium-oxygen non-thermal dielectric barrier discharge (DBD) plasmas on the inactivation of lactate dehydrogenase (LDH) enzyme solutions. Circular dichroism (CD) and dynamic light scattering (DLS) indicate that the loss of activity stems from plasma-induced modification of the secondary molecular structure as well as polymerization of the peptide chains. Raising the treatment intensity leads to a reduced alpha-helix content, increase in the percentage of the beta-sheet regions and random sequence, as well as gradually decreasing LDH activity. However, the structure of the LDH plasma-treated for 300 seconds exhibits a recovery trend after storage for 24 h and its activity also increases slightly. By comparing direct and indirect plasma treatments, plasma-induced LDH inactivation can be attributed to reactive species (RS) in the plasma, especially ones with a long lifetime including hydrogen peroxide, ozone, and nitrate ion which play the major role in the alteration of the macromolecular structure and molecular diameter in lieu of heat, UV radiation, and charged particles.

  12. Identification of proteins interacting with lactate dehydrogenase in claw muscle of the porcelain crab Petrolisthes cinctipes

    PubMed Central

    Cayenne, Andrea P.; Gabert, Beverly; Stillman, Jonathon H.

    2011-01-01

    Biochemical adaptation of enzymes involves conservation of activity, stability and affinity across a wide range of intracellular and environmental conditions. Enzyme adaptation by alteration of primary structure is well known, but the roles of protein-protein interactions in enzyme adaptation are less well understood. Interspecific differences in thermal stability of lactate dehydrogenase (LDH) in porcelain crabs (genus Petrolisthes) are related to intrinsic differences among LDH molecules and by interactions with other stabilizing proteins. Here, we identified proteins that interact with LDH in porcelain crab claw muscle tissue using co-immunoprecipitation, and showed LDH exists in high molecular weight complexes using size exclusion chromatography and Western blot analyses. Co-immunoprecipitated proteins were separated using 2D SDS PAGE and analyzed by LC/ESI using peptide MS/MS. Peptide MS/MS ions were compared to an EST database for Petrolisthes cinctipes to identify proteins. Identified proteins included cytoskeletal elements, glycolytic enzymes, a phosphagen kinase, and the respiratory protein hemocyanin. Our results support the hypothesis that LDH interacts with glycolytic enzymes in a metabolon structured by cytoskeletal elements that may also include the enzyme for transfer of the adenylate charge in glycolytically produced ATP. Those interactions may play specific roles in biochemical adaptation of glycolytic enzymes. PMID:21968246

  13. Ectoparasite Caligus rogercresseyi modifies the lactate response in Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynchus kisutch).

    PubMed

    Vargas-Chacoff, L; Muñoz, J L P; Hawes, C; Oyarzún, R; Pontigo, J P; Saravia, J; González, M P; Mardones, O; Labbé, B S; Morera, F J; Bertrán, C; Pino, J; Wadsworth, S; Yáñez, A

    2017-08-30

    Although Caligus rogercresseyi negatively impacts Chilean salmon farming, the metabolic effects of infection by this sea louse have never been completely characterized. Therefore, this study analyzed lactate responses in the plasma, as well as the liver/muscle lactate dehydrogenase (LDH) activity and gene expression, in Salmo salar and Oncorhynchus kisutch infested by C. rogercresseyi. The lactate responses of Atlantic and Coho salmon were modified by the ectoparasite. Both salmon species showed increasing in plasma levels, whereas enzymatic activity increased in the muscle but decreased in the liver. Gene expression was overexpressed in both Coho salmon tissues but only in the liver for Atlantic salmon. These results suggest that salmonids need more energy to adapt to infection, resulting in increased gene expression, plasma levels, and enzyme activity in the muscles. The responses differed between both salmon species and over the course of infection, suggesting potential species-specific responses to sea-lice infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Diagnostic accuracy of routine blood examinations and CSF lactate level for post-neurosurgical bacterial meningitis.

    PubMed

    Zhang, Yang; Xiao, Xiong; Zhang, Junting; Gao, Zhixian; Ji, Nan; Zhang, Liwei

    2017-06-01

    To evaluate the diagnostic accuracy of routine blood examinations and Cerebrospinal Fluid (CSF) lactate level for Post-neurosurgical Bacterial Meningitis (PBM) at a large sample-size of post-neurosurgical patients. The diagnostic accuracies of routine blood examinations and CSF lactate level to distinguish between PAM and PBM were evaluated with the values of the Area Under the Curve of the Receiver Operating Characteristic (AUC -ROC ) by retrospectively analyzing the datasets of post-neurosurgical patients in the clinical information databases. The diagnostic accuracy of routine blood examinations was relatively low (AUC -ROC <0.7). The CSF lactate level achieved rather high diagnostic accuracy (AUC -ROC =0.891; CI 95%, 0.852-0.922). The variables of patient age, operation duration, surgical diagnosis and postoperative days (the interval days between the neurosurgery and examinations) were shown to affect the diagnostic accuracy of these examinations. The variables were integrated with routine blood examinations and CSF lactate level by Fisher discriminant analysis to improve their diagnostic accuracy. As a result, the diagnostic accuracy of blood examinations and CSF lactate level was significantly improved with an AUC -ROC value=0.760 (CI 95%, 0.737-0.782) and 0.921 (CI 95%, 0.887-0.948) respectively. The PBM diagnostic accuracy of routine blood examinations was relatively low, whereas the accuracy of CSF lactate level was high. Some variables that are involved in the incidence of PBM can also affect the diagnostic accuracy for PBM. Taking into account the effects of these variables significantly improves the diagnostic accuracies of routine blood examinations and CSF lactate level. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. (1-3)-beta-D-glucan in association with lactate dehydrogenase as biomarkers of Pneumocystis pneumonia (PcP) in HIV-infected patients.

    PubMed

    Esteves, F; Lee, C-H; de Sousa, B; Badura, R; Seringa, M; Fernandes, C; Gaspar, J F; Antunes, F; Matos, O

    2014-07-01

    Pneumocystis pneumonia (PcP) is a major HIV-related illness caused by Pneumocystis jirovecii. Definitive diagnosis of PcP requires microscopic detection of P. jirovecii in pulmonary specimens. The objective of this study was to evaluate the usefulness of two serum markers in the diagnosis of PcP. Serum levels of (1-3)-beta-d-glucan (BG) and lactate dehydrogenase (LDH) were investigated in 100 HIV-positive adult patients and 50 healthy blood donors. PcP cases were confirmed using indirect immunofluorescence with monoclonal anti-Pneumocystis antibodies and nested-PCR to amplify the large subunit mitochondrial rRNA gene of P. jirovecii in pulmonary specimens. BG and LDH levels in serum were measured using quantitative microplate-based assays. BG and LDH positive sera were statistically associated with PcP cases (P ≤ 0.001). Sensitivity, specificity, positive/negative predictive values (PPV/NPV), and positive/negative likelihood ratios (PLR/NLR) were 91.3 %, 61.3 %, 85.1 %, 79.2 %, 2.359, and 0.142, respectively, for the BG kit assay, and 91.3 %, 35.5 %, 75.9 %, 64.7 %, 1.415 and 0.245, respectively, for the LDH test. Serologic markers levels combined with the clinical diagnostic criteria for PcP were evaluated for their usefulness in diagnosis of PcP. The most promising cutoff levels for diagnosis of PcP were determined to be 400 pg/ml of BG and 350 U/l of LDH, which combined with clinical data presented 92.8 % sensitivity, 83.9 % specificity, 92.8 % PPV, 83.9 % NPV, 5.764 PLR and 0.086 NLR (P < 0.001). This study confirmed that BG is a reliable indicator for detecting P. jirovecii infection. The combination between BG/LDH levels and clinical data is a promising alternative approach for PcP diagnosis.

  16. Partial reconstruction of in vitro gluconeogenesis arising from mitochondrial l-lactate uptake/metabolism and oxaloacetate export via novel L-lactate translocators.

    PubMed

    De Bari, Lidia; Atlante, Anna; Valenti, Daniela; Passarella, Salvatore

    2004-05-15

    In the light of the occurrence of L-lactate dehydrogenase inside the mitochondrial matrix, we looked at whether isolated rat liver mitochondria can take up and metabolize L-lactate, and provide oxaloacetate outside mitochondria, thus contributing to a partial reconstruction of gluconeogenesis in vitro. We found that: (1) L-lactate (10 mM), added to mitochondria in the presence of a cocktail of glycolysis/gluconeogenesis enzymes and cofactors, can lead to synthesis of glyceraldehyde-3-phosphate at a rate of about 7 nmol/min per mg mitochondrial protein. (2) Three novel translocators exist to mediate L-lactate traffic across the inner mitochondrial membrane. An L-lactate/H+ symporter was identified by measuring fluorimetrically the rate of endogenous pyridine nucleotide reduction. Consistently, L-lactate oxidation was found to occur with P/O ratio=3 (where P/O ratio is the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation) and with generation of membrane potential. Proton uptake, which occurred as a result of addition of L-lactate to RLM together with electron flow inhibitors, and mitochondrial swelling in ammonium L-lactate solutions were also monitored. L-Lactate/oxaloacetate and L-lactate/pyruvate anti-porters were identified by monitoring photometrically the appearance of L-lactate counter-anions outside mitochondria. These L-lactate translocators, which are distinct from the monocarboxylate carrier, were found to differ from each other in V(max) values and in inhibition and pH profiles, and proved to regulate mitochondrial L-lactate metabolism in vitro. The role of lactate/mitochondria interactions in gluconeogenesis is discussed.

  17. Saccharomyces cerevisiae Forms D-2-Hydroxyglutarate and Couples Its Degradation to D-Lactate Formation via a Cytosolic Transhydrogenase.

    PubMed

    Becker-Kettern, Julia; Paczia, Nicole; Conrotte, Jean-François; Kay, Daniel P; Guignard, Cédric; Jung, Paul P; Linster, Carole L

    2016-03-18

    The D or L form of 2-hydroxyglutarate (2HG) accumulates in certain rare neurometabolic disorders, and high D-2-hydroxyglutarate (D-2HG) levels are also found in several types of cancer. Although 2HG has been detected in Saccharomyces cerevisiae, its metabolism in yeast has remained largely unexplored. Here, we show that S. cerevisiae actively forms the D enantiomer of 2HG. Accordingly, the S. cerevisiae genome encodes two homologs of the human D-2HG dehydrogenase: Dld2, which, as its human homolog, is a mitochondrial protein, and the cytosolic protein Dld3. Intriguingly, we found that a dld3Δ knock-out strain accumulates millimolar levels of D-2HG, whereas a dld2Δ knock-out strain displayed only very moderate increases in D-2HG. Recombinant Dld2 and Dld3, both currently annotated as D-lactate dehydrogenases, efficiently oxidized D-2HG to α-ketoglutarate. Depletion of D-lactate levels in the dld3Δ, but not in the dld2Δ mutant, led to the discovery of a new type of enzymatic activity, carried by Dld3, to convert D-2HG to α-ketoglutarate, namely an FAD-dependent transhydrogenase activity using pyruvate as a hydrogen acceptor. We also provide evidence that Ser3 and Ser33, which are primarily known for oxidizing 3-phosphoglycerate in the main serine biosynthesis pathway, in addition reduce α-ketoglutarate to D-2HG using NADH and represent major intracellular sources of D-2HG in yeast. Based on our observations, we propose that D-2HG is mainly formed and degraded in the cytosol of S. cerevisiae cells in a process that couples D-2HG metabolism to the shuttling of reducing equivalents from cytosolic NADH to the mitochondrial respiratory chain via the D-lactate dehydrogenase Dld1. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Lactate Utilization Is Regulated by the FadR-Type Regulator LldR in Pseudomonas aeruginosa

    PubMed Central

    Gao, Chao; Hu, Chunhui; Zheng, Zhaojuan; Jiang, Tianyi; Dou, Peipei; Zhang, Wen; Che, Bin; Wang, Yujiao; Lv, Min

    2012-01-01

    NAD-independent l-lactate dehydrogenase (l-iLDH) and NAD-independent d-lactate dehydrogenase (d-iLDH) activities are induced coordinately by either enantiomer of lactate in Pseudomonas strains. Inspection of the genomic sequences of different Pseudomonas strains revealed that the lldPDE operon comprises 3 genes, lldP (encoding a lactate permease), lldD (encoding an l-iLDH), and lldE (encoding a d-iLDH). Cotranscription of lldP, lldD, and lldE in Pseudomonas aeruginosa strain XMG starts with the base, C, that is located 138 bp upstream of the lldP ATG start codon. The lldPDE operon is located adjacent to lldR (encoding an FadR-type regulator, LldR). The gel mobility shift assays revealed that the purified His-tagged LldR binds to the upstream region of lldP. An XMG mutant strain that constitutively expresses d-iLDH and l-iLDH was found to contain a mutation in lldR that leads to an Ile23-to-serine substitution in the LldR protein. The mutated protein, LldRM, lost its DNA-binding activity. A motif with a hyphenated dyad symmetry (TGGTCTTACCA) was identified as essential for the binding of LldR to the upstream region of lldP by using site-directed mutagenesis. l-Lactate and d-lactate interfered with the DNA-binding activity of LldR. Thus, l-iLDH and d-iLDH were expressed when the operon was induced in the presence of l-lactate or d-lactate. PMID:22408166

  19. Prognostic significance of blood lactate and lactate clearance in trauma patients.

    PubMed

    Régnier, Marie-Alix; Raux, Mathieu; Le Manach, Yannick; Asencio, Yves; Gaillard, Johann; Devilliers, Catherine; Langeron, Olivier; Riou, Bruno

    2012-12-01

    Lactate has been shown to be a prognostic biomarker in trauma. Although lactate clearance has already been proposed as an intermediate endpoint in randomized trials, its precise role in trauma patients remains to be determined. Blood lactate levels and lactate clearance (LC) were calculated at admission and 2 and 4 h later in trauma patients. The association of initial blood lactate level and lactate clearance with mortality was tested using receiver-operating characteristics curve, logistic regression using triage scores, Trauma Related Injury Severity Score as a reference standard, and reclassification method. The authors evaluated 586 trauma patients (mean age 38±16 yr, 84% blunt and 16% penetrating, mortality 13%). Blood lactate levels at admission were elevated in 327 (56%) patients. The lactate clearance should be calculated within the first 2 h after admission as LC0-2 h was correlated with LC0-4 h (R=0.55, P<0.001) but not with LC2-4 h (R=0.04, not significant). The lactate clearance provides additional predictive information to initial blood lactate levels and triage scores and the reference score. This additional information may be summarized using a categorical approach (i.e., less than or equal to -20 %/h) in contrast to initial blood lactate. The results were comparable in patients with high (5 mM/l or more) initial blood lactate. Early (0-2 h) lactate clearance is an important and independent prognostic variable that should probably be incorporated in future decision schemes for the resuscitation of trauma patients.

  20. Rapamycin (mTORC1 inhibitor) reduces the production of lactate and 2-hydroxyglutarate oncometabolites in IDH1 mutant fibrosarcoma cells.

    PubMed

    Hujber, Zoltán; Petővári, Gábor; Szoboszlai, Norbert; Dankó, Titanilla; Nagy, Noémi; Kriston, Csilla; Krencz, Ildikó; Paku, Sándor; Ozohanics, Olivér; Drahos, László; Jeney, András; Sebestyén, Anna

    2017-06-02

    Multiple studies concluded that oncometabolites (e.g. D-2-hydroxyglutarate (2-HG) related to mutant isocitrate dehydrogenase 1/2 (IDH1/2) and lactate) have tumour promoting potential. Regulatory mechanisms implicated in the maintenance of oncometabolite production have great interest. mTOR (mammalian target of rapamycin) orchestrates different pathways, influences cellular growth and metabolism. Considering hyperactivation of mTOR in several malignancies, the question has been addressed whether mTOR operates through controlling of oncometabolite accumulation in metabolic reprogramming. HT-1080 cells - carrying originally endogenous IDH1 mutation - were used in vitro and in vivo. Anti-tumour effects of rapamycin were studied using different assays. The main sources and productions of the oncometabolites (2-HG and lactate) were analysed by 13 C-labeled substrates. Alterations at protein and metabolite levels were followed by Western blot, flow cytometry, immunohistochemistry and liquid chromatography mass spectrometry using rapamycin, PP242 and different glutaminase inhibitors, as well. Rapamycin (mTORC1 inhibitor) inhibited proliferation, migration and altered the metabolic activity of IDH1 mutant HT-1080 cells. Rapamycin reduced the level of 2-HG sourced mainly from glutamine and glucose derived lactate which correlated to the decreased incorporation of 13 C atoms from 13 C-substrates. Additionally, decreased expressions of lactate dehydrogenase A and glutaminase were also observed both in vitro and in vivo. Considering the role of lactate and 2-HG in regulatory network and in metabolic symbiosis it could be assumed that mTOR inhibitors have additional effects besides their anti-proliferative effects in tumours with glycolytic phenotype, especially in case of IDH1 mutation (e.g. acute myeloid leukemias, gliomas, chondrosarcomas). Based on our new results, we suggest targeting mTOR activity depending on the metabolic and besides molecular genetic phenotype of

  1. Tungsten and Molybdenum Regulation of Formate Dehydrogenase Expression in Desulfovibrio vulgaris Hildenborough ▿

    PubMed Central

    da Silva, Sofia M.; Pimentel, Catarina; Valente, Filipa M. A.; Rodrigues-Pousada, Claudina; Pereira, Inês A. C.

    2011-01-01

    Formate is an important energy substrate for sulfate-reducing bacteria in natural environments, and both molybdenum- and tungsten-containing formate dehydrogenases have been reported in these organisms. In this work, we studied the effect of both metals on the levels of the three formate dehydrogenases encoded in the genome of Desulfovibrio vulgaris Hildenborough, with lactate, formate, or hydrogen as electron donors. Using Western blot analysis, quantitative real-time PCR, activity-stained gels, and protein purification, we show that a metal-dependent regulatory mechanism is present, resulting in the dimeric FdhAB protein being the main enzyme present in cells grown in the presence of tungsten and the trimeric FdhABC3 protein being the main enzyme in cells grown in the presence of molybdenum. The putatively membrane-associated formate dehydrogenase is detected only at low levels after growth with tungsten. Purification of the three enzymes and metal analysis shows that FdhABC3 specifically incorporates Mo, whereas FdhAB can incorporate both metals. The FdhAB enzyme has a much higher catalytic efficiency than the other two. Since sulfate reducers are likely to experience high sulfide concentrations that may result in low Mo bioavailability, the ability to use W is likely to constitute a selective advantage. PMID:21498650

  2. Effect of LED phototherapy on blood lactate level in Taekwondo contest

    NASA Astrophysics Data System (ADS)

    Park, H. C.; Lee, B. K.; Lee, S. J.; Lim, S.

    2017-02-01

    The effect of LED phototherapy on blood lactate level in the muscle was studied. A 450cm2 large red and near infrared LED pad with its irradiance of 10mW/cm2 was applied for 10 minutes to brachial muscle and quadriceps muscle of thigh to the participants before and after the Taekwondo contest. Blood samples from the participants were taken at 5 minutes after the competition and 10 minutes after the recovery. The test results showed that the LED therapy (LEDT) before and after the competition had a significant effect on the decrease of blood lactate level of the participants.

  3. Fructose intake during gestation and lactation differentially affects the expression of hippocampal neurosteroidogenic enzymes in rat offspring.

    PubMed

    Mizuno, Genki; Munetsuna, Eiji; Yamada, Hiroya; Ando, Yoshitaka; Yamazaki, Mirai; Murase, Yuri; Kondo, Kanako; Ishikawa, Hiroaki; Teradaira, Ryoji; Suzuki, Koji; Ohashi, Koji

    2017-02-01

    Neurosteroids, steroidal hormones synthesized de novo from cholesterol within the brain, stimulate hippocampal functions such as neuron protection and synapse formation. Previously, we examined the effect of maternal fructose on the transcriptional regulation of neurosteroidogenic enzymes. We found that the mRNA expression level of the steroidogenic acute regulatory protein (StAR), peripheral benzodiazepine receptor (PBR), cytochrome P450(11β), 11β-hydroxysteroid dehydrogenase (HSD), and 17β-HSD was altered. However, we could not determine whether maternal fructose intake played a role in the gestation or lactation period because the dam rats were fed fructose solution during both periods. Thus, in this study, we analyzed the hippocampi of the offspring of dams fed fructose during the gestation or lactation period. Maternal fructose consumption during either the gestation or lactation period did not affect the mRNA levels of StAR, P450(17α), 11β-HSD-2, and 17β-HSD-1. PBR expression was down-regulated, even when rats consumed fructose during the lactation period only, while fructose consumption during gestation tended to activate the expression of P450(11β)-2. We found that maternal fructose intake during gestation and lactation differentially affected the expression of hippocampal neurosteroidogenic enzymes in the offspring.

  4. Changes in creatine kinase, lactate dehydrogenase and aspartate aminotransferase in saliva samples after an intense exercise: a pilot study.

    PubMed

    Barranco, Tomas; Tvarijonaviciute, Asta; Tecles, Fernando; Carrillo, Jose M; Sánchez-Resalt, Cristina; Jimenez-Reyes, Pedro; Rubio, Monica; García-Balletbó, Monserrat; Cerón, Jose J; Cugat, Ramon

    2018-06-01

    The aim of this study was to evaluate changes in the enzymes creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) in saliva before and after an intense exercise consisting of a futsal match. CK, LDH and AST were analyzed in saliva and serum samples of eleven, injury-free, amateur young men before and 30 minutes, 12 hours and 36 hours after a futsal match. A significant increase in CK, LDH and AST was observed after the game in serum samples. In saliva, although a high interindividual variability was found with some individuals no showing increases, significant increases in CK and LDH were observed after the game. No significant changes were observed in saliva AST after the game. Our study showed for first time that CK and LDH can increase in saliva after an intensive exercise consisting on a futsal match. Results suggest that measurements of CK and LDH in saliva could be potentially used to evaluate possible muscle stress or damage in cases of intensive exercise.

  5. Lactate oxidation coupled to energy production in mitochondria like particles from Setaria digitata, a filarial parasite.

    PubMed

    Sivan, V M; Raj, R K

    1994-10-14

    In the filarial parasite, Setaria digitata, the mitochondria like particles (MLP) show NAD reduction with sodium lactate. The MLP also reduces dye and ferricyanide with lactate. The ferricyanide reduction by lactate is found to be sensitive to the cytochrome o inhibitor orthohydroxy diphenyl (OHD) and complex I inhibitor rotenone, modulated by ADP (+) and ATP (-) and inhibited by pyruvate and oxaloacetate. MLP shows lactate oxidation sensitive to OHD, rotenone and sodium malonate. Thus, the lactate utilizing complex system, consisting of an NADH generating MLP bound lactate dehydrogenase and a lactate flavocytochrome reductase tightly linked to complex I and cytochrome o, produces ATP in functional association with fumarate reductase complex and other enzyme systems. Hence, this study provides new dimensions to the study of metabolism in filarial parasites.

  6. Effects of Systemic Metabolic Fuels on Glucose and Lactate Levels in the Brain Extracellular Compartment of the Mouse

    PubMed Central

    Béland-Millar, Alexandria; Larcher, Jeremy; Courtemanche, Justine; Yuan, Tina; Messier, Claude

    2017-01-01

    Classic neuroenergetic research has emphasized the role of glucose, its transport and its metabolism in sustaining normal neural function leading to the textbook statement that it is the necessary and sole metabolic fuel of the mammalian brain. New evidence, including the Astrocyte-to-Neuron Lactate Shuttle hypothesis, suggests that the brain can use other metabolic substrates. To further study that possibility, we examined the effect of intraperitoneally administered metabolic fuels (glucose, fructose, lactate, pyruvate, ß-hydroxybutyrate, and galactose), and insulin, on blood, and extracellular brain levels of glucose and lactate in the adult male CD1 mouse. Primary motor cortex extracellular levels of glucose and lactate were monitored in freely moving mice with the use of electrochemical electrodes. Blood concentration of these same metabolites were obtained by tail vein sampling and measured with glucose and lactate meters. Blood and extracellular fluctuations of glucose and lactate were monitored for a 2-h period. We found that the systemic injections of glucose, fructose, lactate, pyruvate, and ß-hydroxybutyrate increased blood lactate levels. Apart for a small transitory rise in brain extracellular lactate levels, the main effect of the systemic injection of glucose, fructose, lactate, pyruvate, and ß-hydroxybutyrate was an increase in brain extracellular glucose levels. Systemic galactose injections produced a small rise in blood glucose and lactate but almost no change in brain extracellular lactate and glucose. Systemic insulin injections led to a decrease in blood glucose and a small rise in blood lactate; however brain extracellular glucose and lactate monotonically decreased at the same rate. Our results support the concept that the brain is able to use alternative fuels and the current experiments suggest some of the mechanisms involved. PMID:28154523

  7. [Evaluation of the increasing serum lactate dehydrogenase caused by recombinant human granulocyte-colony stimulating factor].

    PubMed

    Sawa, Toshiyuki; Yoshida, Tsutomu; Ikoma, Tetsuroh; Toyoda, Miki; Ohno, Yasushi; Fujiwara, Hisayoshi

    2003-01-01

    Increasing serum lactate dehydrogenase (LDH) is often caused by granulocyte-colony stimulating factor (G-CSF) for leukopenia following chemotherapy in patients with lung cancer. To evaluate the increase in LDH, we investigated the significance of its elevation and LDH isozyme during chemotherapy supported by recombinant human G-CSF (rhG-CSF). To exclude effects of liver diseases and chemotherapy-induced liver dysfunction, only patients in whom laboratory findings concerning liver function were within normal range were entered in this study. If leukocyte or neutrophil counts were less than grade 3, subcutaneous injection of 50 micrograms/m2 of filgrastim was given daily until leukocyte counts increased to more than 10,000/mm3. Sixty patients with unresectable lung cancer were enrolled in this study and the LDH isozyme was evaluable in 54 patients. Increasing LDH was observed in 38 patients(70.4%), and LDH isozyme was measured in these 38 patients. Increases in granulocytes and LDH isozymes were found to have a positive correlation. LDH2, LDH3, LDH4 and LDH5 increased significantly after rhG-CSF administration, although LDH 1 did not increase. It was found that a rapid increase in leukocytes by rhG-CSF induced an increase in LDH, especially LDH 3.4. Considering the results of principal component analysis and the distribution ratio of LDH isozymes in neutrophils, it is thought that elevation of LDH is reflected in the rapid production and consumption of neutrophils.

  8. DNA Sequence Polymorphism of the Lactate Dehydrogenase Genefrom Iranian Plasmodium vivax and Plasmodium falciparum Isolates.

    PubMed

    Getacher Feleke, Daniel; Nateghpour, Mehdi; Motevalli Haghi, Afsaneh; Hajjaran, Homa; Farivar, Leila; Mohebali, Mehdi; Raoofian, Reza

    2015-01-01

    Parasite lactate dehydrogenase (pLDH) is extensively employed as malaria rapid diagnostic tests (RDTs). Moreover, it is a well-known drug target candidate. However, the genetic diversity of this gene might influence performance of RDT kits and its drug target candidacy. This study aimed to determine polymorphism of pLDH gene from Iranian isolates of P. vivax and P. falciparum. Genomic DNA was extracted from whole blood of microscopically confirmed P. vivax and P. falciparum infected patients. pLDH gene of P. falciparum and P. vivax was amplified using conventional PCR from 43 symptomatic malaria patients from Sistan and Baluchistan Province, Southeast Iran from 2012 to 2013. Sequence analysis of 15 P. vivax LDH showed fourteen had 100% identity with P. vivax Sal-1 and Belem strains. Two nucleotide substitutions were detected with only one resulted in amino acid change. Analysis of P. falciparum LDH sequences showed six of the seven sequences had 100% homology with P. falciparum 3D7 and Mzr-1. Moreover, PfLDH displayed three nucleotide changes that resulted in changing only one amino acid. PvLDH and PfLDH showed 75%-76% nucleotide and 90.4%-90.76% amino acid homology. pLDH gene from Iranian P. falciparum and P. vivax isolates displayed 98.8-100% homology with 1-3 nucleotide substitutions. This indicated this gene was relatively conserved. Additional studies can be done weather this genetic variation can influence the performance of pLDH based RDTs or not.

  9. Basal levels of metabolic activity are elevated in Genetic Absence Epilepsy Rats from Strasbourg (GAERS): measurement of regional activity of cytochrome oxidase and lactate dehydrogenase by histochemistry.

    PubMed

    Dufour, Franck; Koning, Estelle; Nehlig, Astrid

    2003-08-01

    The Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are considered an isomorphic, predictive, and homologous model of human generalized absence epilepsy. It is characterized by the expression of spike-and-wave discharges in the thalamus and cortex. In this strain, basal regional rates of cerebral glucose utilization measured by the quantitative autoradiographic [(14)C]2-deoxyglucose technique display a widespread consistent increase compared to a selected strain of genetically nonepileptic rats (NE). In order to verify whether these high rates of glucose metabolism are paralleled by elevated activities of the enzymes of the glycolytic and tricarboxylic acid cycle pathways, we measured by histochemistry the regional activity of the two key enzymes of glucose metabolism, lactate dehydrogenase (LDH) for the anaerobic pathway and cytochrome oxidase (CO) for the aerobic pathway coupled to oxidative phosphorylation. CO and LDH activities were significantly higher in GAERS than in NE rats in 24 and 28 of the 30 brain regions studied, respectively. The differences in CO and LDH activity between both strains were widespread, affected all brain systems studied, and ranged from 12 to 63%. The data of the present study confirm the generalized increase in cerebral glucose metabolism in GAERS, occurring both at the glycolytic and at the oxidative step. However, they still do not allow us to understand why the ubiquitous mutation(s) generates spike-and-wave discharges only in the thalamocortical circuit.

  10. In vitro effects of bicarbonate and bicarbonate-lactate buffered peritoneal dialysis solutions on mesothelial and neutrophil function.

    PubMed

    Topley, N; Kaur, D; Petersen, M M; Jörres, A; Williams, J D; Faict, D; Holmes, C J

    1996-02-01

    The inclusion of bicarbonate in the formulation of peritoneal dialysis solutions may avoid the in vitro impairment of certain cell functions seen with acidic lactate-based fluids. The supranormal physiological levels of HCO3- and PCO2 inherent in such formulations may, however, not be biocompatible. This study compared the in vitro biocompatibility of a pH 5.2 lactate-based formulation with formulations containing either 40 mM lactate at pH 7.4, 38 mM HCO3- at pH 6.8 (PCO2 at approximately 240 mm Hg) or 7.4 (PCO2 at approximately 60 mm Hg), and 25 mM HCO3- plus 15 mM lactate at pH 6.8 (PCO2 at approximately 160 mm Hg) or 7.4 (PCO2 at approximately 40 mm Hg). Significant release of lactate dehydrogenase or decreases in ATP content by human peritoneal mesothelial cells (HPMC) and human peripheral polymorphonuclear leukocytes (PMN) after a 30-min exposure to each test solution was only seen with the pH 5.2 lactate-based fluid. The ATP content of HPMC exposed to this fluid returned to control levels after 30 min of recovery in M199 control medium but showed a trend toward decreasing ATP content at 240 min. Similarly, interleukin (IL)-1 beta-induced IL-6 synthesis by HPMC was also only significantly reduced by the pH 5.2 lactate solution. PMN chemiluminescence was unaffected by 30-min exposure to all test solutions except for the pH 5.2 lactate formulation. Staphylococcus epidermidis phagocytosis was reduced to between 46 to 57% of control with all test solutions except the pH 5.2 lactate solution, which further suppressed the chemiluminescence response to 17% of control. These data suggest that short exposure to supranormal physiological levels of HCO3- and PCO2 does not impair HPMC or PMN viability and function. Furthermore, neutral pH lactate-containing solutions show equivalent biocompatibility to bicarbonate-based ones.

  11. Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

    PubMed

    Fitzgerald, R J; Adams, B O; Sandham, H J; Abhyankar, S

    1989-03-01

    A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

  12. A comparative proteomic analysis of Bacillus coagulans in response to lactate stress during the production of L-lactic acid.

    PubMed

    Wang, Xiuwen; Qin, Jiayang; Wang, Landong; Xu, Ping

    2014-12-01

    The growth rate and maximum biomass of Bacillus coagulans 2-6 were inhibited by lactate; inhibition by sodium lactate was stronger than by calcium lactate. The differences of protein expressions by B. coagulans 2-6 under the lactate stress were determined using two-dimensional electrophoresis coupled with mass spectrometric identification. Under the non-stress condition, calcium lactate stress and sodium lactate stress, the number of detected protein spots was 1,571 ± 117, 1,281 ± 231 and 904 ± 127, respectively. Four proteins with high expression under lactate stress were identified: lactate dehydrogenase, cysteine synthase A, aldo/keto reductase and ribosomal protein L7/L12. These proteins are thus potential targets for the reconstruction of B. coagulans to promote its resistance to lactate stress.

  13. Trimethylamine-N-oxide counteracts urea effects on rabbit muscle lactate dehydrogenase function: a test of the counteraction hypothesis.

    PubMed Central

    Baskakov, I; Wang, A; Bolen, D W

    1998-01-01

    Trimethylamine-N-oxide (TMAO) in the cells of sharks and rays is believed to counteract the deleterious effects of the high intracellular concentrations of urea in these animals. It has been hypothesized that TMAO has the generic ability to counteract the effects of urea on protein structure and function, regardless of whether that protein actually evolved in the presence of these two solutes. Rabbit muscle lactate dehydrogenase (LDH) did not evolve in the presence of either solute, and it is used here to test the validity of the counteraction hypothesis. With pyruvate as substrate, results show that its Km and the combined Km of pyruvate and NADH are increased by urea, decreased by TMAO, and in 1:1 and 2:1 mixtures of urea:TMAO the Km values are essentially equivalent to the Km values obtained in the absence of the two solutes. In contrast, values of k(cat) and the Km for NADH as a substrate are unperturbed by urea, TMAO, or urea:TMAO mixtures. All of these effects are consistent with TMAO counteraction of the effects of urea on LDH kinetic parameters, supporting the premise that counteraction is a property of the solvent system and is independent of the evolutionary history of the protein. PMID:9591690

  14. Total lactate dehydrogenase activity of tail muscle is not cold-adapted in nocturnal lizards from cool-temperate habitats.

    PubMed

    Hare, K M; Miller, J H; Clark, A G; Daugherty, C H

    2005-12-01

    The dependence of metabolic processes on temperature constrains the behavior, physiology and ecology of many ectothermic animals. The evolution of nocturnality in lizards, especially in temperate regions, requires adaptations for activity at low temperatures when optimal body temperatures are unlikely to be obtained. We examined whether nocturnal lizards have cold-adapted lactate dehydrogenase (LDH). LDH was chosen as a representative metabolic enzyme. We measured LDH activity of tail muscle in six lizard species (n=123: three nocturnal, two diurnal and one crepuscular) between 5 and 35 degrees C and found no differences in LDH-specific activity or thermal sensitivity among the species. Similarly, the specific activity and thermal sensitivity of LDH were similar between skinks and geckos. Similar enzyme activities among nocturnal and diurnal lizards indicate that there is no selection of temperature specific LDH enzyme activity at any temperature. As many nocturnal lizards actively thermoregulate during the day, LDH may be adapted for a broad range of temperatures rather than adapted specifically for the low temperatures encountered when the animals are active. The total activity of LDH in tropical and temperate lizards is not cold-adapted. More data are required on biochemical adaptations and whole animal thermal preferences before trends can be established.

  15. Mitochondrial Respiratory Defect Causes Dysfunctional Lactate Turnover via AMP-activated Protein Kinase Activation in Human-induced Pluripotent Stem Cell-derived Hepatocytes*

    PubMed Central

    Im, Ilkyun; Jang, Mi-jin; Park, Seung Ju; Lee, Sang-Hee; Choi, Jin-Ho; Yoo, Han-Wook; Kim, Seyun; Han, Yong-Mahn

    2015-01-01

    A defective mitochondrial respiratory chain complex (DMRC) causes various metabolic disorders in humans. However, the pathophysiology of DMRC in the liver remains unclear. To understand DMRC pathophysiology in vitro, DMRC-induced pluripotent stem cells were generated from dermal fibroblasts of a DMRC patient who had a homoplasmic mutation (m.3398T→C) in the mitochondrion-encoded NADH dehydrogenase 1 (MTND1) gene and that differentiated into hepatocytes (DMRC hepatocytes) in vitro. DMRC hepatocytes showed abnormalities in mitochondrial characteristics, the NAD+/NADH ratio, the glycogen storage level, the lactate turnover rate, and AMPK activity. Intriguingly, low glycogen storage and transcription of lactate turnover-related genes in DMRC hepatocytes were recovered by inhibition of AMPK activity. Thus, AMPK activation led to metabolic changes in terms of glycogen storage and lactate turnover in DMRC hepatocytes. These data demonstrate for the first time that energy depletion may lead to lactic acidosis in the DMRC patient by reduction of lactate uptake via AMPK in liver. PMID:26491018

  16. Response of lactate metabolism in brain glucosensing areas of rainbow trout (Oncorhynchus mykiss) to changes in glucose levels.

    PubMed

    Otero-Rodiño, Cristina; Librán-Pérez, Marta; Velasco, Cristina; Álvarez-Otero, Rosa; López-Patiño, Marcos A; Míguez, Jesús M; Soengas, José L

    2015-12-01

    There is no evidence in fish brain demonstrating the existence of changes in lactate metabolism in response to alterations in glucose levels. We induced in rainbow trout through intraperitoneal (IP) treatments, hypoglycaemic or hyperglycaemic changes to assess the response of parameters involved in lactate metabolism in glucosensing areas like hypothalamus and hindbrain. To distinguish those effects from those induced by peripheral changes in the levels of metabolites or hormones, we also carried out intracerebroventricular (ICV) treatments with 2-deoxy-D-glucose (2-DG, a non-metabolizable glucose analogue thus inducing local glucopenia) or glucose. Finally, we also incubated hypothalamus and hindbrain in vitro in the presence of increased glucose concentrations. The changes in glucose availability were in general correlated to changes in the amount of lactate in both areas. However, when we assessed in these areas the response of parameters related to lactate metabolism, the results obtained were contradictory. The increase in glucose levels did not produce in general the expected changes in those pathways with only a minor increase in their capacity of lactate production. The decrease in glucose levels was, however, more clearly related to a decreased capacity of the pathways involved in the production and use of lactate, and this was especially evident after ICV treatment with 2-DG in both areas. In conclusion, the present results while addressing the existence of changes in lactate metabolism after inducing changes in glucose levels in brain glucosensing areas only partially support the possible existence of an astrocyte-neuron lactate shuttle in hypothalamus and hindbrain of rainbow trout relating glucose availability to lactate production and use.

  17. Brain lactate kinetics: Modeling evidence for neuronal lactate uptake upon activation.

    PubMed

    Aubert, Agnès; Costalat, Robert; Magistretti, Pierre J; Pellerin, Luc

    2005-11-08

    A critical issue in brain energy metabolism is whether lactate produced within the brain by astrocytes is taken up and metabolized by neurons upon activation. Although there is ample evidence that neurons can efficiently use lactate as an energy substrate, at least in vitro, few experimental data exist to indicate that it is indeed the case in vivo. To address this question, we used a modeling approach to determine which mechanisms are necessary to explain typical brain lactate kinetics observed upon activation. On the basis of a previously validated model that takes into account the compartmentalization of energy metabolism, we developed a mathematical model of brain lactate kinetics, which was applied to published data describing the changes in extracellular lactate levels upon activation. Results show that the initial dip in the extracellular lactate concentration observed at the onset of stimulation can only be satisfactorily explained by a rapid uptake within an intraparenchymal cellular compartment. In contrast, neither blood flow increase, nor extracellular pH variation can be major causes of the lactate initial dip, whereas tissue lactate diffusion only tends to reduce its amplitude. The kinetic properties of monocarboxylate transporter isoforms strongly suggest that neurons represent the most likely compartment for activation-induced lactate uptake and that neuronal lactate utilization occurring early after activation onset is responsible for the initial dip in brain lactate levels observed in both animals and humans.

  18. Induction of triglyceride accumulation and mitochondrial maintenance in muscle cells by lactate

    PubMed Central

    Sun, Jingquan; Ye, Xin; Xie, Minhao; Ye, Jianping

    2016-01-01

    Muscle exercise induces intramuscular triglyceride (TG) accumulation and promotes mitochondrial maintenance in myotubes. However, the mechanism underlying exercise effects remains unknown. In this study, lactic acid was tested as a signaling molecule in C2C12 myotubes to understand the mechanism. Intracellular TG storage was induced in the cells by sodium lactate. The lactate activity was observed with an inhibition of the cAMP-PKA pathway as indicated by a reduction in the phosphorylation status of CREB (pCREB). Induction of pCREB signal by forskolin was blocked by pretreatment of cells with lactate. The impact of lactate on mitochondrial function was examined with a focus on the activities of two enzymes, MCAT (malonylCoA:ACP transferase) and PDH (pyruvate dehydrogenase). The enzyme activities were induced in the cells by lactate. Expression of the lactate receptor (GPR81) and lactate transporters (MCT1/4) were induced as well by lactate. The lactate activities were observed at concentrations between 4–64 mM, and were not dependent on the increase in intracellular pyruvate. Pyruvate treatment did not generate the same effects in the cells. Those results suggest that lactate may induce intramuscular TG storage and mitochondrial maintenance in myotubes through inhibition of the cAMP pathway by activation of GPR81 in a positive feedback manner. PMID:27645401

  19. Metabolic engineering of Methanosarcina acetivorans for lactate production from methane.

    PubMed

    McAnulty, Michael J; Poosarla, Venkata Giridhar; Li, Jine; Soo, Valerie W C; Zhu, Fayin; Wood, Thomas K

    2017-04-01

    We previously demonstrated anaerobic conversion of the greenhouse gas methane into acetate using an engineered archaeon that produces methyl-coenzyme M reductase (Mcr) from unculturable microorganisms from a microbial mat in the Black Sea to create the first culturable prokaryote that reverses methanogenesis and grows anaerobically on methane. In this work, we further engineered the same host with the goal of converting methane into butanol. Instead, we discovered a process for converting methane to a secreted valuable product, L-lactate, with sufficient optical purity for synthesizing the biodegradable plastic poly-lactic acid. We determined that the 3-hydroxybutyryl-CoA dehydrogenase (Hbd) from Clostridium acetobutylicum is responsible for lactate production. This work demonstrates the first metabolic engineering of a methanogen with a synthetic pathway; in effect, we produce a novel product (lactate) from a novel substrate (methane) by cloning the three genes for Mcr and one for Hbd. We further demonstrate the utility of anaerobic methane conversion with an increased lactate yield compared to aerobic methane conversion to lactate. Biotechnol. Bioeng. 2017;114: 852-861. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Brain lactate kinetics: Modeling evidence for neuronal lactate uptake upon activation

    PubMed Central

    Aubert, Agnès; Costalat, Robert; Magistretti, Pierre J.; Pellerin, Luc

    2005-01-01

    A critical issue in brain energy metabolism is whether lactate produced within the brain by astrocytes is taken up and metabolized by neurons upon activation. Although there is ample evidence that neurons can efficiently use lactate as an energy substrate, at least in vitro, few experimental data exist to indicate that it is indeed the case in vivo. To address this question, we used a modeling approach to determine which mechanisms are necessary to explain typical brain lactate kinetics observed upon activation. On the basis of a previously validated model that takes into account the compartmentalization of energy metabolism, we developed a mathematical model of brain lactate kinetics, which was applied to published data describing the changes in extracellular lactate levels upon activation. Results show that the initial dip in the extracellular lactate concentration observed at the onset of stimulation can only be satisfactorily explained by a rapid uptake within an intraparenchymal cellular compartment. In contrast, neither blood flow increase, nor extracellular pH variation can be major causes of the lactate initial dip, whereas tissue lactate diffusion only tends to reduce its amplitude. The kinetic properties of monocarboxylate transporter isoforms strongly suggest that neurons represent the most likely compartment for activation-induced lactate uptake and that neuronal lactate utilization occurring early after activation onset is responsible for the initial dip in brain lactate levels observed in both animals and humans. PMID:16260743

  1. Two Levels of Caffeine Ingestion on Blood Lactate and Free Fatty Acid Responses during Incremental Exercise.

    ERIC Educational Resources Information Center

    McNaughton, Lars

    1987-01-01

    Research was conducted to determine the effects of two doses of caffeine on the lactate threshold and also to examine the effects on substrate utilization during incremental cycle ergometry. Results found that caffeine increased heart rates and free fatty acid levels for all workloads and decreased blood lactate levels at some of the workloads.…

  2. Genetic polymorphism and isoenzyme patterns of lactate dehydrogenase in tench (Tinca tinca), crucian carp (Carassius carassius) and carp (Cyprinus carpio).

    PubMed

    Valenta, M; Slechta, V; Slechtová, V; Kálal, L

    1977-01-01

    Isoenzyme patterns and the polymorphism of lactate dehydrogenase (LDH) were investigated in 3 fish species of family Cyprinidae, i.e. tench (Tinca tinca), crucian carp (Carassius carassius) and carp (Cyprinus carpio). The isoenzyme patterns were tissue and species specific. In crucian carp subunits with different electrophoretic mobility are present, which are genetically controlled from the B1, B2, A1, A2 and C loci, while the set of loci in carp is B1, B2, A, C1 and C2 and in tench B, A, C. The locus B of LDH in tench, the locus B2 in crucian carp, and the loci B1, C1 and C2 in carp are polymorphic and have two different alleles in each case. The polymorphism did not affect the total LDH activity in the tissues. All the populations investigated were in Hardy-Weinberg equilibrium. The genetic control of the polymorphism in B1 and C1 loci in carp was proved by test matings. The polymorphism in B loci tested in erythrocytes may be utilized as genetic markers in the fish breeding.

  3. Inhibition of lactation.

    PubMed

    Llewellyn-Jones, D

    1975-01-01

    The mechanism and hormonal regulation of lactation is explained and illustrated with a schematic representation. Circulating estrogen above a critical amount seems to be the inhibitory factor controlling lactation during pregnancy. Once delivery occurs, the level of estrogen falls, that of prolactin rises, and lactation begins. Nonsuckling can be used to inhibit lactation. Estrogens can also be used to inhibit lactation more quickly and with less pain. The reported association between estrogens and puerperal thromboembolism cannot be considered conclusive due to defects in the reporting studies. There is no reason not to use estrogens in lactation inhibition except for women over 35 who experienced a surgical delivery. Alternative therapy is available for these women. The recently-developed drug, brom-ergocryptine, may replace other methods of lactation inhibition.

  4. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is necessary for ethanol production in Clostridium thermocellum and Thermoanaerobacterium saccharolyticum.

    PubMed

    Lo, Jonathan; Zheng, Tianyong; Hon, Shuen; Olson, Daniel G; Lynd, Lee R

    2015-04-01

    Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are anaerobic thermophilic bacteria being investigated for their ability to produce biofuels from plant biomass. The bifunctional alcohol and aldehyde dehydrogenase gene, adhE, is present in these bacteria and has been known to be important for ethanol formation in other anaerobic alcohol producers. This study explores the inactivation of the adhE gene in C. thermocellum and T. saccharolyticum. Deletion of adhE reduced ethanol production by >95% in both T. saccharolyticum and C. thermocellum, confirming that adhE is necessary for ethanol formation in both organisms. In both adhE deletion strains, fermentation products shifted from ethanol to lactate production and resulted in lower cell density and longer time to reach maximal cell density. In T. saccharolyticum, the adhE deletion strain lost >85% of alcohol dehydrogenase (ADH) activity. Aldehyde dehydrogenase (ALDH) activity did not appear to be affected, although ALDH activity was low in cell extracts. Adding ubiquinone-0 to the ALDH assay increased activity in the T. saccharolyticum parent strain but did not increase activity in the adhE deletion strain, suggesting that ALDH activity was inhibited. In C. thermocellum, the adhE deletion strain lost >90% of ALDH and ADH activity in cell extracts. The C. thermocellum adhE deletion strain contained a point mutation in the lactate dehydrogenase gene, which appears to deregulate its activation by fructose 1,6-bisphosphate, leading to constitutive activation of lactate dehydrogenase. Thermoanaerobacterium saccharolyticum and Clostridium thermocellum are bacteria that have been investigated for their ability to produce biofuels from plant biomass. They have been engineered to produce higher yields of ethanol, yet questions remain about the enzymes responsible for ethanol formation in these bacteria. The genomes of these bacteria encode multiple predicted aldehyde and alcohol dehydrogenases which could be

  5. Systematic Engineering of Escherichia coli for d-Lactate Production from Crude Glycerol.

    PubMed

    Wang, Zei Wen; Saini, Mukesh; Lin, Li-Jen; Chiang, Chung-Jen; Chao, Yun-Peng

    2015-11-04

    Crude glycerol resulting from biodiesel production is an abundant and renewable resource. However, the impurities in crude glycerol usually make microbial fermentation problematic. This issue was addressed by systematic engineering of Escherichia coli for the production of d-lactate from crude glycerol. First, mgsA and the synthetic pathways of undesired products were eliminated in E. coli, rendering the strain capable of homofermentative production of optically pure d-lactate. To direct carbon flux toward d-lactate, the resulting strain was endowed with an enhanced expression of glpD-glpK in the glycerol catabolism and of a heterologous gene encoding d-lactate dehydrogenase. Moreover, the strain was evolved to improve its utilization of cruder glycerol and subsequently equipped with the FocA channel to export intracellular d-lactate. Finally, the fed-batch fermentation with two-phase culturing was carried out with a bioreactor. As a result, the engineered strain enabled production of 105 g/L d-lactate (99.9% optical purity) from 121 g/L crude glycerol at 40 h. The result indicates the feasibility of our approach to engineering E. coli for the crude glycerol-based fermentation.

  6. Responses of blood pressure and lactate levels to various aquatic exercise movements in postmenopausal women.

    PubMed

    Chien, K-Y; Chen, W-C; Kan, N-W; Hsu, M-C; Lee, S-L

    2015-12-01

    Middle-aged and elderly women represent the main attending group in head-out aquatic exercise (HOAE). Blood pressure (BP) significantly increases both during water immersion and aquatic walking. Based on risk concerns, it is important to evaluate BP responses in postmenopausal women doing HOAE. The aim of this study was to determine BP, lactate levels, and rating of perceived exertion (RPE) changes associated with performing 3 different movements at 3 levels of exercise intensity in water. Twelve postmenopausal women (59.9±0.6 years old) participated in 3 aquatic trials involving running (RU), rocking (RO), and scissor kicks (SK) on separate days. Systolic BP, mean arterial pressure (MAP), lactate levels, RPE, and motion cadence were measured at rest; upon reaching 50%, 65%, and 80% of heart rate reserve for 6 minutes; and 10 and 30 minutes after exercise. Under similar RPE responses at 3 levels of intensity, SK resulted in higher systolic BP, MAP, and lactate levels than RO at 10 minutes after exercise (P<0.05) and the lowest motion cadence (P<0.05). RO resulted in the lowest MAP and diastolic BP responses during exercise (P<0.05). RU resulted in lower responses of lactate levels at high exercise intensity (P<0.05). RO resulted in lower diastolic BP and MAP responses compared with RU and SK during exercise. These findings suggest that RO movement in aquatic exercises is more suitable for people at high risk for cardiovascular disease.

  7. Elevated lactate during psychogenic hyperventilation.

    PubMed

    ter Avest, E; Patist, F M; Ter Maaten, J C; Nijsten, M W N

    2011-04-01

    Elevated arterial lactate levels are closely related to morbidity and mortality in various patient categories. In the present retrospective study, the relation between arterial lactate, partial pressure of carbon dioxide (Pco(2)) and pH was systematically investigated in patients who visited the emergency department (ED) with psychogenic hyperventilation. Over a 5-month period, all the patients who visited the ED of a university hospital with presumed psychogenic hyperventilation were evaluated. Psychogenic hyperventilation was presumed to be present when an increased respiratory rate (>20 min) was documented at or before the ED visit and when somatic causes explaining the hyperventilation were absent. Arterial blood gas and lactate levels (reference values 0.5-1.5 mmol/l) were immediately measured by a point-of-care analyser that was managed and calibrated by the central laboratory. During the study period, 46 patients were diagnosed as having psychogenic hyperventilation. The median (range) Pco(2) for this group was 4.3 (2.0-5.5) kPa, the pH was 7.47 (7.40-7.68) and the lactate level was 1.2 (0.5-4.4) mmol/l. 14 participants (30%) had a lactate level above the reference value of 1.5 mmol/l. Pco(2) was the most important predictor of lactate in multivariate analysis. None of the participants underwent any medical treatment other than observation at the ED or had been hospitalised after their ED visit. In patients with psychogenic hyperventilation, lactate levels are frequently elevated. Whereas high lactates are usually associated with acidosis and an increased risk of poor outcome, in patients with psychogenic hyperventilation, high lactates are associated with hypocapnia and alkalosis. In this context, elevated arterial lactate levels should not be regarded as an adverse sign.

  8. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    DOE PAGES

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy; ...

    2016-02-23

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resultedmore » in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels.« less

  9. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resultedmore » in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels.« less

  10. Bioconversion of methane to lactate by an obligate methanotrophic bacterium

    PubMed Central

    Henard, Calvin A.; Smith, Holly; Dowe, Nancy; Kalyuzhnaya, Marina G.; Pienkos, Philip T.; Guarnieri, Michael T.

    2016-01-01

    Methane is the second most abundant greenhouse gas (GHG), with nearly 60% of emissions derived from anthropogenic sources. Microbial conversion of methane to fuels and value-added chemicals offers a means to reduce GHG emissions, while also valorizing this otherwise squandered high-volume, high-energy gas. However, to date, advances in methane biocatalysis have been constrained by the low-productivity and limited genetic tractability of natural methane-consuming microbes. Here, leveraging recent identification of a novel, tractable methanotrophic bacterium, Methylomicrobium buryatense, we demonstrate microbial biocatalysis of methane to lactate, an industrial platform chemical. Heterologous overexpression of a Lactobacillus helveticus L-lactate dehydrogenase in M. buryatense resulted in an initial titer of 0.06 g lactate/L from methane. Cultivation in a 5 L continuously stirred tank bioreactor enabled production of 0.8 g lactate/L, representing a 13-fold improvement compared to the initial titer. The yields (0.05 g lactate/g methane) and productivity (0.008 g lactate/L/h) indicate the need and opportunity for future strain improvement. Additionally, real-time analysis of methane utilization implicated gas-to-liquid transfer and/or microbial methane consumption as process limitations. This work opens the door to develop an array of methanotrophic bacterial strain-engineering strategies currently employed for biocatalytic sugar upgrading to “green” chemicals and fuels. PMID:26902345

  11. Effects of Sesame (Sesamum indicum L.) Supplementation on Creatine Kinase, Lactate Dehydrogenase, Oxidative Stress Markers, and Aerobic Capacity in Semi-Professional Soccer Players

    PubMed Central

    Barbosa, Carlos V. da Silva; Silva, Alexandre S.; de Oliveira, Caio V. C.; Massa, Nayara M. L.; de Sousa, Yasmim R. F.; da Costa, Whyara K. A.; Silva, Ayice C.; Delatorre, Plínio; Carvalho, Rhayane; Braga, Valdir de Andrade; Magnani, Marciane

    2017-01-01

    Nutritional intervention with antioxidants rich foods has been considered a strategy to minimize the effects of overtraining in athletes. This experimental, randomized, and placebo-controlled study evaluated the effects of consumption of sesame (Sesamum indicum L.) on muscle damage markers, oxidative stress, systemic inflammation, and aerobic performance in male semi-professional soccer players. Twenty athletes were randomly assigned to groups that received 40 g (two tablespoons) per day of sesame or a placebo during 28 days of regular training (exposed to routine training that includes loads of heavy training in the final half of the season). Before and after intervention, creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), C-reactive protein (hs-CRP), and aerobic capacity were evaluated. Before intervention, a physiologic imbalance was noted in both groups related to CK and LDH levels. Sesame intake caused a reduction of CK (19%, p < 0.05), LDH (37%, p < 0.05), MDA (55%, p < 0.05) and hs-CRP (53%, p < 0.05) and increased SOD (14%, p < 0.05), vitamin A (25%, p < 0.05), and vitamin E (65%, p < 0.05) in the experimental group. These phenomena were accompanied by increased aerobic capacity (17%, p < 0.05). The placebo group showed an increase in CK (5%, p < 0.05) and no significant change in LDH, SOD or vitamin A. MDA levels decreased (21%, p < 0.05) and vitamin E increased (14%, p < 0.05) in the placebo group, but to a much lesser extent than in the experimental group. These results show that sesame consumption may reduce muscle damage and oxidative stress while improving the aerobic capacity in soccer players. PMID:28408889

  12. Hair cortisol levels of lactating dairy cows in cold- and warm-temperate regions in Japan.

    PubMed

    Uetake, Katsuji; Morita, Shigeru; Sakagami, Nobutada; Yamamoto, Kazuaki; Hashimura, Shinji; Tanaka, Toshio

    2018-02-01

    We compared the hair cortisol levels of lactating dairy cows in a cold- and a warm-temperate region out of four climatic zones in Japan. We simultaneously investigated the effects of calving number, lactation period and month of hair sampling. Hair of nine Holstein lactating cows chosen from each region (i.e. 18 cows per sampling) was sampled in March, June, September and December. Number of calvings (1, 2, ≥3) and lactation duration (early: <100, middle: 101-200, and late: >201 days) were balanced between regions. Cortisol was extracted from hair by methanol, and its level was determined with a cortisol immunoassay kit. A multi-way analysis of variance revealed that the effects of month of hair sampling (P < 0.001) and its combination with region (P < 0.05) were significant. In a multiple comparison test, significant differences (P < 0.01) in hair cortisol level (pg/mg of hair) were found between June (13.0 ± 1.0) and the other 3 months, and between September (1.6 ± 0.2) and December (4.5 ± 0.3). The rise in cortisol level from March to June was more intense in the cold-temperate region. These results demonstrate the necessity of considering seasonal variations in each climatic region when we use hair cortisol level as an indicator of stress. © 2017 Japanese Society of Animal Science.

  13. Antimalarial Activity of Potential Inhibitors of Plasmodium falciparum Lactate Dehydrogenase Enzyme Selected by Docking Studies

    PubMed Central

    Penna-Coutinho, Julia; Cortopassi, Wilian Augusto; Oliveira, Aline Alves; França, Tanos Celmar Costa; Krettli, Antoniana Ursine

    2011-01-01

    The Plasmodium falciparum lactate dehydrogenase enzyme (PfLDH) has been considered as a potential molecular target for antimalarials due to this parasite's dependence on glycolysis for energy production. Because the LDH enzymes found in P. vivax, P. malariae and P. ovale (pLDH) all exhibit ∼90% identity to PfLDH, it would be desirable to have new anti-pLDH drugs, particularly ones that are effective against P. falciparum, the most virulent species of human malaria. Our present work used docking studies to select potential inhibitors of pLDH, which were then tested for antimalarial activity against P. falciparum in vitro and P. berghei malaria in mice. A virtual screening in DrugBank for analogs of NADH (an essential cofactor to pLDH) and computational studies were undertaken, and the potential binding of the selected compounds to the PfLDH active site was analyzed using Molegro Virtual Docker software. Fifty compounds were selected based on their similarity to NADH. The compounds with the best binding energies (itraconazole, atorvastatin and posaconazole) were tested against P. falciparum chloroquine-resistant blood parasites. All three compounds proved to be active in two immunoenzymatic assays performed in parallel using monoclonals specific to PfLDH or a histidine rich protein (HRP2). The IC50 values for each drug in both tests were similar, were lowest for posaconazole (<5 µM) and were 40- and 100-fold less active than chloroquine. The compounds reduced P. berghei parasitemia in treated mice, in comparison to untreated controls; itraconazole was the least active compound. The results of these activity trials confirmed that molecular docking studies are an important strategy for discovering new antimalarial drugs. This approach is more practical and less expensive than discovering novel compounds that require studies on human toxicology, since these compounds are already commercially available and thus approved for human use. PMID:21779323

  14. The prognostic value of blood lactate levels relative to that of vital signs in the pre-hospital setting: a pilot study

    PubMed Central

    Jansen, Tim C; van Bommel, Jasper; Mulder, Paul G; Rommes, Johannes H; Schieveld, Selma JM; Bakker, Jan

    2008-01-01

    Introduction A limitation of pre-hospital monitoring is that vital signs often do not change until a patient is in a critical stage. Blood lactate levels are suggested as a more sensitive parameter to evaluate a patient's condition. The aim of this pilot study was to find presumptive evidence for a relation between pre-hospital lactate levels and in-hospital mortality, corrected for vital sign abnormalities. Methods In this prospective observational study (n = 124), patients who required urgent ambulance dispatching and had a systolic blood pressure below 100 mmHg, a respiratory rate less than 10 or more than 29 breaths/minute, or a Glasgow Coma Scale (GCS) below 14 were enrolled. Nurses from Emergency Medical Services measured capillary or venous lactate levels using a hand-held device on arrival at the scene (T1) and just before or on arrival at the emergency department (T2). The primary outcome measured was in-hospital mortality. Results The average (standard deviation) time from T1 to T2 was 27 (10) minutes. Non-survivors (n = 32, 26%) had significantly higher lactate levels than survivors at T1 (5.3 vs 3.7 mmol/L) and at T2 (5.4 vs 3.2 mmol/L). Mortality was significantly higher in patients with lactate levels of 3.5 mmol/L or higher compared with those with lactate levels below 3.5 mmol/L (T1: 41 vs 12% and T2: 47 vs 15%). Also in the absence of hypotension, mortality was higher in those with higher lactate levels. In a multivariable Cox proportional hazard analysis including systolic blood pressure, heart rate, GCS (all at T1) and delta lactate level (from T1 to T2), only delta lactate level (hazard ratio (HR) = 0.20, 95% confidence interval (CI) = 0.05 to 0.76, p = 0.018) and GCS (HR = 0.93, 95% CI = 0.88 to 0.99, p = 0.022) were significant independent predictors of in-hospital mortality. Conclusions In a cohort of patients that required urgent ambulance dispatching, pre-hospital blood lactate levels were associated with in-hospital mortality and provided

  15. Changes in Plasma Progesterone Levels in the Caudal Vena Cava and the Jugular Vein and Luteinizing Hormone Secretion Pattern After Feeding in Lactating and Non-lactating Dairy Cows

    PubMed Central

    ENDO, Natsumi; NAGAI, Kiyosuke; TANAKA, Tomomi; KAMOMAE, Hideo

    2012-01-01

    Abstract The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a catheter inserted from the coccygeal vein) and the jugular vein every 15 min for 12 h (0500–1700 h) during the functional luteal phase. Cows were fed 50% of the daily diet 6 h after the start of blood sampling. During the 12-h sampling period, mean progesterone concentrations in the caudal vena cava did not differ between lactating and non-lactating cows (49.0 ± 2.9 and 53.3 ± 3.7 ng/ml; mean ± SE), whereas mean progesterone concentrations in the jugular vein in lactating cows were higher than those in non-lactating cows (6.4 ± 0.1 and 5.6 ± 0.1 ng/ml, P < 0.001). Lactating cows had a higher frequency of LH pulses than non-lactating cows (7.0 ± 0.7 and 4.3 ± 0.9 pulses/12 h, P<0.05). The influence of feeding was not observed on LH profiles but was observed on progesterone profiles in both veins. Progesterone concentrations in the caudal vena cava increased after feeding in both groups. Progesterone concentrations in the jugular vein decreased after feeding in lactating cows but not in non-lactating cows. These results indicate the difference in feeding-related changes in progesterone dynamics between lactating and non-lactating cows. PMID:23171608

  16. Transport of pyruvate and lactate in yeast mitochondria.

    PubMed

    Briquet, M

    1977-02-07

    Evidence for the existence of mediated transport of pyruvate and lactate in isolated mitochondria of Saccharomyces cerevisiae is presented. 1. The mitochondrial oxidation of pyruvate is specifically inhibited by the monocarboxylic oxoacids alpha-ketoisocaproate and by alpha-cyano-3-hydroxycinnamate, while pyruvate and malate dehydrogenases activities are not inhibited. 2. The stimulation of the mitochondrial oxidations of succinate, alpha-ketoglutarate and citrate by pyruvate are also inhibited by alpha-cyano-3-hydroxycinnamate. 3. The [14C]pyruvate uptake by yeast mitochondria follows saturation kinetics and is completely inhibited by alpha-cyano-3-hydroxycinnamate. 4. Large amplitude passive swellings of mitochondria of the wild type and of cytoplasmic rho- and rho-n mutants are induced by isoosmotic ammonium pyruvate and lactate. These pH-dependent swellings are inhibited by alpha-cyano-3-hydroxycinnamate suggesting that the carrier system is not coded by mitochondrial DNA.

  17. Secondary Increase of Lactate Levels in Asphyxiated Newborns during Hypothermia Treatment: Reflect of Suboptimal Hemodynamics (A Case Series and Review of the Literature)

    PubMed Central

    Al Balushi, Asim; Guilbault, Marie-Pier; Wintermark, Pia

    2015-01-01

    Objective To evaluate whether a secondary increase of serum lactate levels in asphyxiated newborns during hypothermia treatment may reflect suboptimal dynamics. Methods–Retrospective case series and review of the literature. We present the clinical course of four asphyxiated newborns treated with hypothermia who presented with hypotension requiring inotropic support, and who displayed a secondary increase of serum lactate levels during hypothermia treatment. Serial serum lactate levels are correlated with blood pressure and inotropic support within the first 96 hours of life. Results Lactate levels initially decreased in the four patients. However, each of them started to present lower blood pressure, and lactate levels started to increase again. Inotropic support was started to raise blood pressure. The introduction of an epinephrine drip consistently worsened the increase of lactate levels in these newborns, whereas dopamine and dobutamine enabled the clearance of lactate in addition to raising the blood pressure. Rewarming was associated with hemodynamics perturbations (a decrease of blood pressure and/or an increase of lactate levels) in the three newborns who survived. Conclusions Lactate levels during the first 4 days of life should be followed as a potential marker for suboptimal hemodynamic status in term asphyxiated newborns treated with hypothermia, for whom the maintenance of homeostasis during hypothermia treatment is of utmost importance to alleviate brain injury. PMID:26929870

  18. [Variations of peripheral blood autoantibody, immunoglobuliln, and complement levels in patients with non-lactational mastitis and their clinical significances].

    PubMed

    Xu, Rui; Guo, Qian-Qian; Yang, Le-Ping; Lai, Mi-Lin; Tong, Lin

    2016-08-20

    To detect the variations in peripheral blood levels of autoantibodies, immunoglobulilns and complements in patients with non-lactational mastitis and investigate whether non-lactational mastitis is an autoimmune disease with immune dysfunction. Seven-eight patients with non-lactational mastitis treated in our hospital between September 2013 and May 2015 and 88 healthy women (control) were examined for peripheral blood levels of antinuclear antibody (ANA), anti-histone antibody (AHA), immunoglobulins (IgA, IgM, and IgG) and complements (C3, C4, and total complements). s Of the 78 patients with non-lactational mastitis, 50 (64.10%) were positive of ANA showing mainly the granular and cytoplasmic granular fluorescence patterns, and the positivity rate was significantly higher than that in the control group (P<0.000). Twenty-eight (36.00%) of the patients were positive of AHA, a rate significantly higher than that in the control group (P<0.000). The levels of IgA, IgM, C4, and total complements levels were all significantly elevated in the patients compared with those in the control group (P<0.05). Patients with non-lactational mastitis have abnormal changes in peripheral blood levels of immunoglobulins and complements with high positivity rates for ANA and AHA, indicating that non-lactational mastitis is an autoimmune disease with immune dysfunction.

  19. Lactate dehydrogenase downregulation mediates the inhibitory effect of diallyl trisulfide on proliferation, metastasis, and invasion in triple-negative breast cancer.

    PubMed

    Cheng, Shi-Yann; Yang, Yao-Chih; Ting, Kuan-Lun; Wen, Su-Ying; Viswanadha, Vijaya Padma; Huang, Chih-Yang; Kuo, Wei-Wen

    2017-04-01

    The Warburg effect plays a critical role in tumorigenesis, suggesting that specific agents targeting Warburg effect key proteins may be a promising strategy for cancer therapy. Previous studies have shown that diallyl trisulfide (DATS) inhibits proliferation of breast cancer cells by inducing apoptosis in vitro and in vivo. However, whether the Warburg effect is involved with the apoptosis-promoting action of DATS is unclear. Here, we show that the action of DATS is associated with downregulation of lactate dehydrogenase A (LDHA), an essential protein of the Warburg effect whose upregulation is closely related to tumorigenesis. Interestingly, inhibition of the Warburg effect by DATS in breast cancer cells did not greatly affect normal cells. Furthermore, DATS inhibited growth of breast cancer cells, particularly in MDA-MB-231, a triple-negative breast cancer (TNBC) cell, and reduced proliferation and migration; invasion was reversed by over-expression of LDHA. These data suggest that DATS inhibits breast cancer growth and aggressiveness through a novel pathway targeting the key enzyme of the Warburg effect. Our study shows that LDHA downregulation is involved in the apoptotic effect of DATS on TNBC. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1390-1398, 2017. © 2016 Wiley Periodicals, Inc.

  20. The negative impact of α-ketoglutarate dehydrogenase complex deficiency on matrix substrate-level phosphorylation

    PubMed Central

    Kiss, Gergely; Konrad, Csaba; Doczi, Judit; Starkov, Anatoly A.; Kawamata, Hibiki; Manfredi, Giovanni; Zhang, Steven F.; Gibson, Gary E.; Beal, M. Flint; Adam-Vizi, Vera; Chinopoulos, Christos

    2013-01-01

    A decline in α-ketoglutarate dehydrogenase complex (KGDHC) activity has been associated with neurodegeneration. Provision of succinyl-CoA by KGDHC is essential for generation of matrix ATP (or GTP) by substrate-level phosphorylation catalyzed by succinyl-CoA ligase. Here, we demonstrate ATP consumption in respiration-impaired isolated and in situ neuronal somal mitochondria from transgenic mice with a deficiency of either dihydrolipoyl succinyltransferase (DLST) or dihydrolipoyl dehydrogenase (DLD) that exhibit a 20–48% decrease in KGDHC activity. Import of ATP into the mitochondrial matrix of transgenic mice was attributed to a shift in the reversal potential of the adenine nucleotide translocase toward more negative values due to diminished matrix substrate-level phosphorylation, which causes the translocase to reverse prematurely. Immunoreactivity of all three subunits of succinyl-CoA ligase and maximal enzymatic activity were unaffected in transgenic mice as compared to wild-type littermates. Therefore, decreased matrix substrate-level phosphorylation was due to diminished provision of succinyl-CoA. These results were corroborated further by the finding that mitochondria from wild-type mice respiring on substrates supporting substrate-level phosphorylation exhibited ∼30% higher ADP-ATP exchange rates compared to those obtained from DLST+/− or DLD+/− littermates. We propose that KGDHC-associated pathologies are a consequence of the inability of respiration-impaired mitochondria to rely on “in-house” mitochondrial ATP reserves.—Kiss, G., Konrad, C., Doczi, J., Starkov, A. A., Kawamata, H., Manfredi, G., Zhang, S. F., Gibson, G. E., Beal, M. F., Adam-Vizi, V., Chinopoulos, C. The negative impact of α-ketoglutarate dehydrogenase complex deficiency on matrix substrate-level phosphorylation. PMID:23475850

  1. Effects of interaction with gene carrier polyethyleneimines on conformation and enzymatic activity of pig heart lactate dehydrogenase.

    PubMed

    Wang, Fan; Mo, Junyong; Huang, Aimin; Zhang, Min; Ma, Lin

    2018-06-15

    Polyethyleneimine (PEI) has long been considered as "golden standard" for polymeric gene delivery carrier, however also induces cytotoxicity. To make a further insight into the molecular basis of PEI cytotoxicity, fluorescence, absorption and circular dichroism spectroscopy were conducted to investigate the influence of PEI (average molecular weight 25,000 and 1800 Da) on the conformation of pig heart lactate dehydrogenase (LDH) and its catalytic efficiency. Zeta-potential measurement and isothermal titration calorimetry were used to reveal the interaction between PEI and LDH. PEI was found to bind onto the surface of LDH predominantly via hydrophobic interaction, inducing a more compact conformation and an increased surface hydrophobicity of the enzyme. The conformational change of LDH induced by PEI binding had little influence on the complex formation between LDH and reduced nicotinamide adenine dinucleotide (NADH, the co-enzyme). However, the nonspecific binding of PEI on the surface of LDH retarded the turnover of the enzyme. Meanwhile, the large quantity of amine groups on the polymer chain made PEI subject to form complexes with NADH and pyruvate (the substrate) via hydrogen bond and electrostatic interaction, which greatly reduced the binding efficient of LDH. The polymer size played an important role in PEI-LDH interaction. The smaller size of lower molecular weight PEI facilitated the close contact with LDH and consequential reduction of the turnover number of the enzyme. However, higher molecular weight PEI was more favorable for competitive binding with NADH and pyruvate and generally decreased the catalytic efficient of LDH. Copyright © 2018. Published by Elsevier B.V.

  2. Mildly elevated lactate levels are associated with microcirculatory flow abnormalities and increased mortality: a microSOAP post hoc analysis.

    PubMed

    Vellinga, Namkje A R; Boerma, E Christiaan; Koopmans, Matty; Donati, Abele; Dubin, Arnaldo; Shapiro, Nathan I; Pearse, Rupert M; van der Voort, Peter H J; Dondorp, Arjen M; Bafi, Tony; Fries, Michael; Akarsu-Ayazoglu, Tulin; Pranskunas, Andrius; Hollenberg, Steven; Balestra, Gianmarco; van Iterson, Mat; Sadaka, Farid; Minto, Gary; Aypar, Ulku; Hurtado, F Javier; Martinelli, Giampaolo; Payen, Didier; van Haren, Frank; Holley, Anthony; Gomez, Hernando; Mehta, Ravindra L; Rodriguez, Alejandro H; Ruiz, Carolina; Canales, Héctor S; Duranteau, Jacques; Spronk, Peter E; Jhanji, Shaman; Hubble, Sheena; Chierego, Marialuisa; Jung, Christian; Martin, Daniel; Sorbara, Carlo; Bakker, Jan; Ince, Can

    2017-10-18

    Mildly elevated lactate levels (i.e., 1-2 mmol/L) are increasingly recognized as a prognostic finding in critically ill patients. One of several possible underlying mechanisms, microcirculatory dysfunction, can be assessed at the bedside using sublingual direct in vivo microscopy. We aimed to evaluate the association between relative hyperlactatemia, microcirculatory flow, and outcome. This study was a predefined subanalysis of a multicenter international point prevalence study on microcirculatory flow abnormalities, the Microcirculatory Shock Occurrence in Acutely ill Patients (microSOAP). Microcirculatory flow abnormalities were assessed with sidestream dark-field imaging. Abnormal microcirculatory flow was defined as a microvascular flow index (MFI) < 2.6. MFI is a semiquantitative score ranging from 0 (no flow) to 3 (continuous flow). Associations between microcirculatory flow abnormalities, single-spot lactate measurements, and outcome were analyzed. In 338 of 501 patients, lactate levels were available. For this substudy, all 257 patients with lactate levels ≤ 2 mmol/L (median [IQR] 1.04 [0.80-1.40] mmol/L) were included. Crude ICU mortality increased with each lactate quartile. In a multivariable analysis, a lactate level > 1.5 mmol/L was independently associated with a MFI < 2.6 (OR 2.5, 95% CI 1.1-5.7, P = 0.027). In a heterogeneous ICU population, a single-spot mildly elevated lactate level (even within the reference range) was independently associated with increased mortality and microvascular flow abnormalities. In vivo microscopy of the microcirculation may be helpful in discriminating between flow- and non-flow-related causes of mildly elevated lactate levels. ClinicalTrials.gov, NCT01179243 . Registered on August 3, 2010.

  3. Stable Suppression of Lactate Dehydrogenase Activity during Anoxia in the Foot Muscle of Littorina littorea and the Potential Role of Acetylation as a Novel Posttranslational Regulatory Mechanism

    PubMed Central

    Shahriari, Ali; Dawson, Neal J.; Bell, Ryan A. V.; Storey, Kenneth B.

    2013-01-01

    The intertidal marine snail, Littorina littorea, has evolved to withstand extended bouts of oxygen deprivation brought about by changing tides or other potentially harmful environmental conditions. Survival is dependent on a strong suppression of its metabolic rate and a drastic reorganization of its cellular biochemistry in order to maintain energy balance under fixed fuel reserves. Lactate dehydrogenase (LDH) is a crucial enzyme of anaerobic metabolism as it is typically responsible for the regeneration of NAD+, which allows for the continued functioning of glycolysis in the absence of oxygen. This study compared the kinetic and structural characteristics of the D-lactate specific LDH (E.C. 1.1.1.28) from foot muscle of aerobic control versus 24 h anoxia-exposed L. littorea. Anoxic LDH displayed a near 50% decrease in V max (pyruvate-reducing direction) as compared to control LDH. These kinetic differences suggest that there may be a stable modification and regulation of LDH during anoxia, and indeed, subsequent dot-blot analyses identified anoxic LDH as being significantly less acetylated than the corresponding control enzyme. Therefore, acetylation may be the regulatory mechanism that is responsible for the suppression of LDH activity during anoxia, which could allow for the production of alternative glycolytic end products that in turn would increase the ATP yield under fixed fuel reserves. PMID:24233354

  4. The relationship between lactate and thiamine levels in patients with diabetic ketoacidosis.

    PubMed

    Moskowitz, Ari; Graver, Amanda; Giberson, Tyler; Berg, Katherine; Liu, Xiaowen; Uber, Amy; Gautam, Shiva; Donnino, Michael W

    2014-02-01

    Thiamine functions as an important cofactor in aerobic metabolism and thiamine deficiency can contribute to lactic acidosis. Although increased rates of thiamine deficiency have been described in diabetic outpatients, this phenomenon has not been studied in relation to diabetic ketoacidosis (DKA). In the present study, we hypothesize that thiamine deficiency is associated with elevated lactate in patients with DKA. This was a prospective observational study of patients presenting to a tertiary care center with DKA. Patient demographics, laboratory results, and outcomes were recorded. A one-time blood draw was performed and analyzed for plasma thiamine levels. Thirty-two patients were enrolled. Eight patients (25%) were thiamine deficient, with levels lower than 9 nmol/L. A negative correlation between lactic acid and plasma thiamine levels was found (r = -0.56, P = .002). This relationship remained significant after adjustment for APACHE II scores (P = .009). Thiamine levels were directly related to admission serum bicarbonate (r = 0.44, P = .019), and patients with thiamine deficiency maintained lower bicarbonate levels over the first 24 hours (slopes parallel with a difference of 4.083, P = .002). Patients with DKA had a high prevalence of thiamine deficiency. Thiamine levels were inversely related to lactate levels among patients with DKA. A study of thiamine supplementation in DKA is warranted. © 2013.

  5. A novel mode of lactate metabolism in strictly anaerobic bacteria.

    PubMed

    Weghoff, Marie Charlotte; Bertsch, Johannes; Müller, Volker

    2015-03-01

    Lactate is a common substrate for major groups of strictly anaerobic bacteria, but the biochemistry and bioenergetics of lactate oxidation is obscure. The high redox potential of the pyruvate/lactate pair of E0 ' = -190 mV excludes direct NAD(+) reduction (E0 ' = -320 mV). To identify the hitherto unknown electron acceptor, we have purified the lactate dehydrogenase (LDH) from the strictly anaerobic, acetogenic bacterium Acetobacterium woodii. The LDH forms a stable complex with an electron-transferring flavoprotein (Etf) that exhibited NAD(+) reduction only when reduced ferredoxin (Fd(2-) ) was present. Biochemical analyses revealed that the LDH/Etf complex of A. woodii uses flavin-based electron confurcation to drive endergonic lactate oxidation with NAD(+) as oxidant at the expense of simultaneous exergonic electron flow from reduced ferredoxin (E0 ' ≈ -500 mV) to NAD(+) according to: lactate + Fd(2-)  + 2 NAD(+)  → pyruvate + Fd + 2 NADH. The reduced Fd(2-) is regenerated from NADH by a sequence of events that involves conversion of chemical (ATP) to electrochemical ( Δ μ ˜ Na + ) and finally redox energy (Fd(2-) from NADH) via reversed electron transport catalysed by the Rnf complex. Inspection of genomes revealed that this metabolic scenario for lactate oxidation may also apply to many other anaerobes. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Use of admission serum lactate and sodium levels to predict mortality in necrotizing soft-tissue infections.

    PubMed

    Yaghoubian, Arezou; de Virgilio, Christian; Dauphine, Christine; Lewis, Roger J; Lin, Matthew

    2007-09-01

    Simple admission laboratory values can be used to classify patients with necrotizing soft-tissue infection (NSTI) into high and low mortality risk groups. Chart review. Public teaching hospital. All patients with NSTI from 1997 through 2006. Variables analyzed included medical history, admission vital signs, laboratory values, and microbiologic findings. Data analyses included univariate and classification and regression tree analyses. Mortality. One hundred twenty-four patients were identified with NSTI. The overall mortality rate was 21 of 124 (17%). On univariate analysis, factors associated with mortality included a history of cancer (P = .03), intravenous drug abuse (P < .001), low systolic blood pressure on admission (P = .03), base deficit (P = .009), and elevated white blood cell count (P = .06). On exploratory classification and regression tree analysis, admission serum lactate and sodium levels were predictors of mortality, with a sensitivity of 100%, specificity of 28%, positive predictive value of 23%, and negative predictive value of 100%. A serum lactate level greater than or equal to 54.1 mg/dL (6 mmol/L) alone was associated with a 32% mortality, whereas a serum sodium level greater than or equal to 135 mEq/L combined with a lactate level less than 54.1 mg/dL was associated with a mortality of 0%. Mortality for NSTIs remains high. A simple model, using admission serum lactate and serum sodium levels, may help identify patients at greatest risk for death.

  7. Correlation between normal glucose-6-phosphate dehydrogenase level and haematological parameters.

    PubMed

    Ajlaan, S K; al-Naama, L M; al-Naama, M M

    2000-01-01

    The study involved 143 individuals and aimed to correlate normal glucose-6-phosphate dehydrogenase (G6PD) level with haematological parameters. A statistically significant negative correlation was found between G6PD level and haemoglobin, packed cell volume, red blood cell count, mean corpuscular haemoglobin and mean corpuscular volume. A statistically significant positive correlation was found between G6PD level and white blood cell count and reticulocyte count, but no significant correlation was found between G6PD level and mean corpuscular haemoglobin concentration. The negative correlation between G6PD level and haemoglobin suggests that anaemic people have higher G6PD levels than normal individuals. The positive correlation between G6PD level and white blood cell count indicates that white blood cells may play an important role in contributing to G6PD level.

  8. Acute and chronic effects of clofibrate and clofibric acid on the enzymes acetylcholinesterase, lactate dehydrogenase and catalase of the mosquitofish, Gambusia holbrooki.

    PubMed

    Nunes, B; Carvalho, F; Guilhermino, L

    2004-12-01

    The objective of this study was to investigate both acute and chronic effects of clofibrate and clofibric acid on the enzymes acetylcholinesterase (AChE), lactate dehydrogenase (LDH) and catalase (CAT) of the mosquitofish (Gambusia holbrooki). AChE, commonly used as a biomarker of neurotoxicity, was determined in the total head. LDH, an important enzyme of anaerobic metabolism, was quantified in dorsal muscle, and CAT, enzyme which has been used as indicative parameter of peroxisome proliferation, was determined in the liver. Furthermore, alterations of body and liver weight were also determined, through the calculation of the ratios final body weight/initial body weight, liver weight/final body weight, liver weight/gills weight and liver weight/head weight. Acute exposure of G. holbrooki to both clofibrate and clofibric acid induced a decrease in liver CAT activity, an increase in muscle LDH activity, while no effects were observed on AChE activity. However, chronic exposure did not alter significantly the enzymatic activities, suggesting reduced or null effects over these pathways, relative to effects reported in other species. No effects were observed for the calculated ratios, except a significant weight reduction for males chronically exposed to clofibrate.

  9. The relationship between lactate and thiamine levels in patients with diabetic ketoacidosis⋆

    PubMed Central

    Moskowitz, Ari; Graver, Amanda; Giberson, Tyler; Berg, Katherine; Liu, Xiaowen; Uber, Amy; Gautam, Shiva; Donnino, Michael W.

    2013-01-01

    Purpose Thiamine functions as an important cofactor in aerobic metabolism and thiamine deficiency can contribute to lactic acidosis. Although increased rates of thiamine deficiency have been described in diabetic outpatients, this phenomenon has not been studied in relation to diabetic ketoacidosis (DKA). In the present study, we hypothesize that thiamine deficiency is associated with elevated lactate in patients with DKA. Materials and Methods This was a prospective observational study of patients presenting to a tertiary care center with DKA. Patient demographics, laboratory results, and outcomes were recorded. A one-time blood draw was performed and analyzed for plasma thiamine levels. Results Thirty-two patients were enrolled. Eight patients (25%) were thiamine deficient, with levels lower than 9 nmol/L. A negative correlation between lactic acid and plasma thiamine levels was found (r = −0.56, P = .002). This relationship remained significant after adjustment for APACHE II scores (P = .009). Thiamine levels were directly related to admission serum bicarbonate (r = 0.44, P = .019), and patients with thiamine deficiency maintained lower bicarbonate levels over the first 24 hours (slopes parallel with a difference of 4.083, P = .002). Conclusions Patients with DKA had a high prevalence of thiamine deficiency. Thiamine levels were inversely related to lactate levels among patients with DKA. A study of thiamine supplementation in DKA is warranted. PMID:23993771

  10. Impaired hippocampal glucose metabolism during and after flurothyl-induced seizures in mice: Reduced phosphorylation coincides with reduced activity of pyruvate dehydrogenase.

    PubMed

    McDonald, Tanya S; Borges, Karin

    2017-07-01

    To determine changes in glucose metabolism and the enzymes involved in the hippocampus ictally and postictally in the acute mouse flurothyl seizure model. [U- 13 C]-Glucose was injected (i.p.) prior to, or following a 5 min flurothyl-induced seizure. Fifteen minutes later, mice were killed and the total metabolite levels and % 13 C enrichment were analyzed in the hippocampal formation using gas chromatography-mass spectrometry. Activities of key metabolic and antioxidant enzymes and the phosphorylation status of pyruvate dehydrogenase were measured, along with lipid peroxidation. During seizures, total lactate levels increased 1.7-fold; however, [M + 3] enrichment of both lactate and alanine were reduced by 30% and 43%, respectively, along with a 28% decrease in phosphofructokinase activity. Postictally the % 13 C enrichments of all measured tricarboxylic acid (TCA) cycle intermediates and the amino acids were reduced by 46-93%. At this time, pyruvate dehydrogenase (PDH) activity was 56% of that measured in controls, and there was a 1.9-fold increase in the phosphorylation of PDH at ser232. Phosphorylation of PDH is known to decrease its activity. Here, we show that the increase of lactate levels during flurothyl seizures is from a source other than [U- 13 C]-glucose, such as glycogen. Surprisingly, although we saw a reduction in phosphofructokinase activity during the seizure, metabolism of [U- 13 C]-glucose into the TCA cycle seemed unaffected. Similar to our recent findings in the chronic phase of the pilocarpine model, postictally the metabolism of glucose by glycolysis and the TCA cycle was impaired along with reduced PDH activity. Although this decrease in activity may be a protective mechanism to reduce oxidative stress, which is observed in the flurothyl model, ATP is critical to the recovery of ion and neurotransmitter balance and return to normal brain function. Thus we identified promising novel strategies to enhance energy metabolism and recovery from

  11. A lactate dehydrogenase ELISA-based assay for the in vitro determination of Plasmodium berghei sensitivity to anti-malarial drugs.

    PubMed

    Orjuela-Sánchez, Pamela; Duggan, Erika; Nolan, John; Frangos, John A; Carvalho, Leonardo Jm

    2012-11-05

    Plasmodium berghei rodent malaria is a well-known model for the investigation of anti-malarial drug efficacy in vivo. However, the availability of drug in vitro assays in P. berghei is reduced when compared with the spectrum of techniques existing for Plasmodium falciparum. New alternatives to the current manual or automated methods described for P. berghei are attractive. The present study reports a new ELISA drug in vitro assay for P. berghei using two monoclonal antibodies against the parasite lactate dehydrogenase (pLDH). This procedure includes a short-in vitro culture, the purification of schizonts and the further generation of synchronized mice infections. Early stages of the parasite are then incubated against different concentrations of anti-malarial drugs using micro-plates. The novelty of this procedure in P. berghei relies on the quantification of the drug activity derived from the amount of pLDH estimated by an ELISA assay using two monoclonal antibodies: 14C1 and 19G7. The IC₅₀s obtained through the ELISA assay were compared with those from the micro-test. The initial parameters of the synchronized samples used in the in vitro assays were a parasitaemia of 0.5% and haematocrit of 1%, with an incubation period of 22 hours at 36.5°C. pLDH detection using a 14C1 coating at 10 μg/ml and 19G7 at 2.5 × 10⁻³ μg/ml provided good readouts of optical densities with low background in negative controls and specific detection levels for all parasite stages. IC₅₀s values derived from the ELISA assay for artesunate, chloroquine, amodiaquine and quinine were: 15, 7, 2, and 144 nM, respectively. When artesunate and chloroquine IC₅₀s were evaluated using the micro-test similar values were obtained. This ELISA-based in vitro drug assay is easy to implement, fast, and avoids the use radioisotopes or expensive equipment. The utility of this simple assay for screening anti-malarial drug activity against P. berghei in vitro is demonstrated.

  12. Serum lactate dehydrogenase with a systemic inflammation score is useful for predicting response and survival in patients with newly diagnosed diffuse large B-cell lymphoma.

    PubMed

    Jung, Sung-Hoon; Yang, Deok-Hwan; Ahn, Jae-Sook; Kim, Yeo-Kyeoung; Kim, Hyeoung-Joon; Lee, Je-Jung

    2015-01-01

    We evaluated the relationship between serum lactate dehydrogenase (LDH) level with systemic inflammation score and survival in 213 patients with diffuse large B-cell lymphoma (DLBCL) receiving R-CHOP chemotherapy. The patients were classified into 3 groups based on LDH with the Glasgow Prognostic Score (L-GPS). A score of 2 was assigned to patients with elevated C-reactive protein, hypoalbuminemia and elevated LDH, a score of 1 to those with one or two abnormalities and a score of 0 to those with no abnormality. In multivariate analysis, independent poor prognostic factors for progression-free survival were L-GPS 2 [hazard ratio (HR) 5.415, p = 0.001], Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2 (HR 3.504, p = 0.001) and bulky lesion (HR 2.030, p = 0.039). Independent poor prognostic factors for overall survival were L-GPS 2 (HR 5.898, p = 0.001) and ECOG PS ≥2 (HR 3.525, p = 0.001). The overall response rate for the R-CHOP chemotherapy decreased according to the L-GPS; it was 96.7% at L-GPS 0, 87% at L-GPS 1 and 75% at L-GPS 2 (p = 0.009). L-GPS based on systemic inflammatory indicators may be a useful clinical prognostic indicator for survival, and predicts the response for R-CHOP chemotherapy in patients with newly diagnosed DLBCL. © 2014 S. Karger AG, Basel.

  13. Testicular lactate content is compromised in men with Klinefelter Syndrome.

    PubMed

    Alves, Marco G; Martins, Ana D; Jarak, Ivana; Barros, Alberto; Silva, Joaquina; Sousa, Mário; Oliveira, Pedro F

    2016-03-01

    Klinefelter syndrome (KS) is the most common genetic cause of human infertility, but the mechanism(s) responsible for its phenotype remain largely unknown. KS is associated with alterations in body composition and with a higher risk of developing metabolic diseases. We therefore hypothesized that KS men seeking fertility treatment possess an altered testicular metabolism profile that may hamper the nutritional support of spermatogenesis. Testicular biopsies from control (46, XY) (n = 6) and KS (47, XXY) (n = 6) individuals were collected and analyzed by proton high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy. The mRNA and protein expression of crucial glycolysis-associated enzymes and transporters were evaluated in parallel by quantitative PCR and Western blot, respectively. Our data revealed altered regulation of glucose transporters (GLUT1 and GLUT3); phosphofructokinase 1, liver isoform (PFKL); and lactate dehydrogenase A (LDHA) expression in the testis of KS patients. Moreover, we detected a severe reduction in lactate and creatine accumulation within testicular tissue from KS men. The aberrant levels of the biomarkers detected in testicular biopsies of KS men may therefore be associated with the infertility phenotypes presented by these men. Mol. Reprod. Dev. 83: 208-216, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  14. Higher thermostability of l-lactate dehydrogenases is a key factor in decreasing the optical purity of d-lactic acid produced from Lactobacillus coryniformis.

    PubMed

    Gu, Sol-A; Jun, Chanha; Joo, Jeong Chan; Kim, Seil; Lee, Seung Hwan; Kim, Yong Hwan

    2014-05-10

    Lactobacillus coryniformis is known to produce d-lactic acid as a dominant fermentation product at a cultivation temperature of approximately 30°C. However, the considerable production of l-lactic acid is observed when the fermentation temperature is greater than 40°C. Because optically pure lactates are synthesized from pyruvate by the catalysis of chiral-specific d- or l-lactate dehydrogenase, the higher thermostability of l-LDHs is assumed to be one of the key factors decreasing the optical purity of d-lactic acid produced from L. coryniformis at high temperature. To verify this hypothesis, two types of d-ldh genes and six types of l-ldh genes based on the genomic information of L. coryniformis were synthesized and expressed in Escherichia coli. Among the LDHs tested, five LDHs showed activity and were used to construct polyclonal antibodies. d-LDH1, l-LDH2, and l-LDH3 were found to be expressed in L. coryniformis by Western blotting analysis. The half-life values (t1/2) of the LDHs at 40°C were estimated to be 10.50, 41.76, and 2311min, and the T50(10) values were 39.50, 39.90, and 58.60°C, respectively. In addition, the Tm values were 36.0, 41.0, and 62.4°C, respectively, which indicates that l-LDH has greater thermostability than d-LDH. The higher thermostability of l-LDHs compared with that of d-LDH1 may be a major reason why the enantiopurity of d-lactic acid is decreased at high fermentation temperatures. The key enzymes characterized will suggest a direction for the design of genetically modified lactic acid bacteria to produce optically pure d-lactic acid. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Enhancing the light-driven production of D-lactate by engineering cyanobacterium using a combinational strategy

    NASA Astrophysics Data System (ADS)

    Li, Chao; Tao, Fei; Ni, Jun; Wang, Yu; Yao, Feng; Xu, Ping

    2015-05-01

    It is increasingly attractive to engineer cyanobacteria for bulk production of chemicals from CO2. However, cofactor bias of cyanobacteria is different from bacteria that prefer NADH, which hampers cyanobacterial strain engineering. In this study, the key enzyme D-lactate dehydrogenase (LdhD) from Lactobacillus bulgaricus ATCC11842 was engineered to reverse its favored cofactor from NADH to NADPH. Then, the engineered enzyme was introduced into Synechococcus elongatus PCC7942 to construct an efficient light-driven system that produces D-lactic acid from CO2. Mutation of LdhD drove a fundamental shift in cofactor preference towards NADPH, and increased D-lactate productivity by over 3.6-fold. We further demonstrated that introduction of a lactic acid transporter and bubbling CO2-enriched air also enhanced D-lactate productivity. Using this combinational strategy, increased D-lactate concentration and productivity were achieved. The present strategy may also be used to engineer cyanobacteria for producing other useful chemicals.

  16. Early changes in coagulation profiles and lactate levels in patients with septic shock undergoing extracorporeal membrane oxygenation

    PubMed Central

    Kim, Hyoung Soo; Cheon, Dae Young; Ha, Sang Ook; Han, Sang Jin; Kim, Hyun-Sook; Lee, Sun Hee; Kim, Sung Gyun

    2018-01-01

    Background To investigate the impact of coagulation profiles and lactate levels in patients with septic shock undergoing extracorporeal membrane oxygenation (ECMO). Methods A retrospective analysis of coagulation profiles, including disseminated intravascular coagulation (DIC) score, before and during 48 h of ECMO support [on day 0 (pre-ECMO), day 1, and day 2], was conducted in patients with septic shock undergoing ECMO. Results A total of 37 patients were included, and 15 (40.5%) patients survived. The initial DIC scores did not change in either the pre-ECMO overt-DIC (n=15) or non-overt-DIC (n=22) group after ECMO commencement. However, the DIC scores were significantly higher, at all three time-points, in non-survivors than in survivors. Additionally, the lactate levels improved considerably in the pre-ECMO non-overt-DIC group and in survivors during ECMO support, but not in the pre-ECMO overt DIC group or non-survivors. On a multivariate analysis, the pre-ECMO DIC score was significantly associated with hospital death [odds ratio (OR), 3.935; 95% confidence interval (CI), 1.170–13.230]. Receiver operating characteristic (ROC) curves revealed that the combination of pre-ECMO DIC score plus lactate level was the best predictor of hospital death (area under the curve, 0.879; 0.771–0.987); patients with combined scores >9.35 (the optimal cut-off) exhibited a three-fold higher mortality rate than did those with lower scores (81.8% vs. 26.7%, P=0.001). Conclusions During the early period of ECMO support, the coagulation profiles and lactate levels exhibited different trajectories in survivors and non-survivors. Furthermore, the pre-ECMO DIC score plus lactate level was the best predictor of hospital death. PMID:29707291

  17. Novel model of neuronal bioenergetics: postsynaptic utilization of glucose but not lactate correlates positively with Ca2+ signalling in cultured mouse glutamatergic neurons.

    PubMed

    Bak, Lasse K; Obel, Linea F; Walls, Anne B; Schousboe, Arne; Faek, Sevan A A; Jajo, Farah S; Waagepetersen, Helle S

    2012-04-05

    We have previously investigated the relative roles of extracellular glucose and lactate as fuels for glutamatergic neurons during synaptic activity. The conclusion from these studies was that cultured glutamatergic neurons utilize glucose rather than lactate during NMDA (N-methyl-d-aspartate)-induced synaptic activity and that lactate alone is not able to support neurotransmitter glutamate homoeostasis. Subsequently, a model was proposed to explain these results at the cellular level. In brief, the intermittent rises in intracellular Ca2+ during activation cause influx of Ca2+ into the mitochondrial matrix thus activating the tricarboxylic acid cycle dehydrogenases. This will lead to a lower activity of the MASH (malate-aspartate shuttle), which in turn will result in anaerobic glycolysis and lactate production rather than lactate utilization. In the present work, we have investigated the effect of an ionomycin-induced increase in intracellular Ca2+ (i.e. independent of synaptic activity) on neuronal energy metabolism employing 13C-labelled glucose and lactate and subsequent mass spectrometric analysis of labelling in glutamate, alanine and lactate. The results demonstrate that glucose utilization is positively correlated with intracellular Ca2+ whereas lactate utilization is not. This result lends further support for a significant role of glucose in neuronal bioenergetics and that Ca2+ signalling may control the switch between glucose and lactate utilization during synaptic activity. Based on the results, we propose a compartmentalized CiMASH (Ca2+-induced limitation of the MASH) model that includes intracellular compartmentation of glucose and lactate metabolism. We define pre- and post-synaptic compartments metabolizing glucose and glucose plus lactate respectively in which the latter displays a positive correlation between oxidative metabolism of glucose and Ca2+ signalling.

  18. High-Level Production of the Low-Calorie Sugar Sorbitol by Lactobacillus plantarum through Metabolic Engineering▿

    PubMed Central

    Ladero, Victor; Ramos, Ana; Wiersma, Anne; Goffin, Philippe; Schanck, André; Kleerebezem, Michiel; Hugenholtz, Jeroen; Smid, Eddy J.; Hols, Pascal

    2007-01-01

    Sorbitol is a low-calorie sugar alcohol that is largely used as an ingredient in the food industry, based on its sweetness and its high solubility. Here, we investigated the capacity of Lactobacillus plantarum, a lactic acid bacterium found in many fermented food products and in the gastrointestinal tract of mammals, to produce sorbitol from fructose-6-phosphate by reverting the sorbitol catabolic pathway in a mutant strain deficient for both l- and d-lactate dehydrogenase activities. The two sorbitol-6-phosphate dehydrogenase (Stl6PDH) genes (srlD1 and srlD2) identified in the genome sequence were constitutively expressed at a high level in this mutant strain. Both Stl6PDH enzymes were shown to be active, and high specific activity could be detected in the overexpressing strains. Using resting cells under pH control with glucose as a substrate, both Stl6PDHs were capable of rerouting the glycolytic flux from fructose-6-phosphate toward sorbitol production with a remarkably high efficiency (61 to 65% glucose conversion), which is close to the maximal theoretical value of 67%. Mannitol production was also detected, albeit at a lower level than the control strain (9 to 13% glucose conversion), indicating competition for fructose-6-phosphate rerouting by natively expressed mannitol-1-phosphate dehydrogenase. By analogy, low levels of this enzyme were detected in both the wild-type and the lactate dehydrogenase-deficient strain backgrounds. After optimization, 25% of sugar conversion into sorbitol was achieved with cells grown under pH control. The role of intracellular NADH pools in the determination of the maximal sorbitol production is discussed. PMID:17261519

  19. Increased circulating D-lactate levels predict risk of mortality after hemorrhage and surgical trauma in baboons.

    PubMed

    Sobhian, Babak; Kröpfl, Albert; Hölzenbein, Thomas; Khadem, Anna; Redl, Heinz; Bahrami, Soheyl

    2012-05-01

    Patients with hemorrhagic shock and/or trauma are at risk of developing colonic ischemia associated with bacterial translocation that may lead to multiple organ failure and death. Intestinal ischemia is difficult to diagnose noninvasively. The present retrospective study was designed to determine whether circulating plasma D-lactate is associated with mortality in a clinically relevant two-hit model in baboons. Hemorrhagic shock was induced in anesthetized baboons (n = 24) by controlled bleeding (mean arterial pressure, 40 mmHg), base excess (maximum -5 mmol/L), and time (maximum 3 h). To mimic clinical setting more closely, all animals underwent a surgical trauma after resuscitation including midshaft osteotomy stabilized with reamed femoral interlocking nailing and were followed for 7 days. Hemorrhagic shock/surgical trauma resulted in 66% mortality by day 7. In nonsurvivor (n = 16) hemorrhagic shock/surgical trauma baboons, circulating D-lactate levels were significantly increased (2-fold) at 24 h compared with survivors (n = 8), whereas the early increase during hemorrhage and resuscitation declined during the early postresuscitation phase with no difference between survivors and nonsurvivors. Moreover, D-lactate levels remained elevated in the nonsurvival group until death, whereas it decreased to baseline in survivors. Prediction of death (receiver operating characteristic test) by D-lactate was accurate with an area under the curve (days 1-3 after trauma) of 0.85 (95% confidence interval, 0.72-0.93). The optimal D-lactate cutoff value of 25.34 μg/mL produced sensitivity of 73% to 99% and specificity of 50% to 83%. Our data suggest that elevation of plasma D-lactate after 24 h predicts an increased risk of mortality after hemorrhage and trauma.

  20. Macromolecular crowding effect upon in vitro enzyme kinetics: mixed activation-diffusion control of the oxidation of NADH by pyruvate catalyzed by lactate dehydrogenase.

    PubMed

    Balcells, Cristina; Pastor, Isabel; Vilaseca, Eudald; Madurga, Sergio; Cascante, Marta; Mas, Francesc

    2014-04-17

    Enzyme kinetics studies have been usually designed as dilute solution experiments, which differ substantially from in vivo conditions. However, cell cytosol is crowded with a high concentration of molecules having different shapes and sizes. The consequences of such crowding in enzymatic reactions remain unclear. The aim of the present study is to understand the effect of macromolecular crowding produced by dextran of different sizes and at diverse concentrations in the well-known reaction of oxidation of NADH by pyruvate catalyzed by L-lactate dehydrogenase (LDH). Our results indicate that the reaction rate is determined by both the occupied volume and the relative size of dextran obstacles with respect to the enzyme present in the reaction. Moreover, we analyzed the influence of macromolecular crowding on the Michaelis-Menten constants, vmax and Km. The obtained results show that only high concentrations and large sizes of dextran reduce both constants suggesting a mixed activation-diffusion control of this enzymatic reaction due to the dextran crowding action. From our knowledge, this is the first experimental study that depicts mixed activation-diffusion control in an enzymatic reaction due to the effect of crowding.

  1. Serum lactate dehydrogenase profile as a retrospective indicator of uterine preparedness for labor: a prospective, observational study

    PubMed Central

    2013-01-01

    Background Lactate dehydrogenase (LDH) isoenzymes are required for adenosine triphosphate production, with each of five different isoenzymes having varying proficiencies in anaerobic versus aerobic environments. With advancing pregnancy, the isoenzyme profile in uterine muscle shifts toward a more anaerobic profile, speculatively to facilitate uterine efficiency during periods of low oxygen that accompany labor contractions. Profile shifting may even occur throughout labor. Maternal serum LDH levels between 24–48 hours following delivery predominantly originate from uterine muscle, reflecting the enzymatic state of the myometrium during labor. Our purpose was to describe serum LDH isoenzymes 24–30 hours post-delivery to determine if cervical dilation rates following labor admission were associated with a particular LDH profile. We also compared differences in post-delivery LDH isoenzyme profiles between women admitted in pre-active versus established active labor. Methods Low-risk, nulliparous women with spontaneous labor onset were sampled (n = 91). Maternal serum LDH was measured at labor admission and 24–30 hours post-vaginal delivery. Rates of cervical dilation during the first four hours after admission were also measured. Spearman’s rho coefficients were used for association testing and t tests evaluated for group and paired-sample differences. Results More efficient dilation following admission was associated with decreased LDH1 (p = 0.029) and increased LDH3 and LDH4 (p = 0.017 and p = 0.017, respectively) in the post-delivery period. Women admitted in established active labor had higher relative serum levels of LDH3 (t = 2.373; p = 0.023) and LDH4 (t = 2.268; p = 0.029) and lower levels of LDH1 (t = 2.073; p = 0.045) and LDH5 (t = 2.041; p = 0.048) when compared to women admitted in pre-active labor. Despite having similar dilatations at admission (3.4 ± 0.5 and 3.7 ± 0.6 cm, respectively

  2. Acute metformin overdose: examining serum pH, lactate level, and metformin concentrations in survivors versus nonsurvivors: a systematic review of the literature.

    PubMed

    Dell'Aglio, Damon M; Perino, Louis J; Kazzi, Ziad; Abramson, Jerome; Schwartz, Michael D; Morgan, Brent W

    2009-12-01

    Metformin is known to cause potentially fatal metabolic acidosis with an increased lactate level in both overdose and therapeutic use. No association between mortality and serum pH, lactate level, or metformin concentrations, though intuitive, has yet been described. This systematic literature review is designed to evaluate the association between mortality and serum pH, lactate level, and metformin concentrations in acute metformin overdose. We reviewed the literature by using the MEDLINE, EMBASE, CINAHL, and TOXNET databases for cases of metformin overdose with documented mortality data and values of serum pH, lactate level, and metformin concentrations. When available, patient age, patient sex, and whether patients received intravenous sodium bicarbonate therapy or hemodialysis were also analyzed. Cases meeting inclusion criteria were analyzed to determine whether a difference in distribution of nadir serum pH, peak serum lactate level, or peak serum metformin concentrations existed between overdose survivors and nonsurvivors. We identified 10 articles that had 1 or more cases meeting our inclusion criteria. In total, there were 22 cases of metformin overdose (5/22 died) that met inclusion criteria. No intentional overdose patients died whose serum pH nadir was greater than 6.9, maximum lactate concentration less than 25 mol/L, or maximum metformin concentration less than 50 microg/mL (therapeutic range 1 to 2 microg/mL). Intentional overdose patients with a nadir serum pH less than 6.9 had 83% mortality (5/6), those with lactate concentration greater than 25 mmol/L had 83% mortality (5/6), and those with metformin concentration greater than 50 microg/mL had 38% mortality (5/12). Nadir serum pH and peak serum lactate and metformin concentration distributions in survivors and nonsurvivors revealed that survivors had a median nadir pH of 7.30, interquartile range (IQR) 7.22, 7.36; nonsurvivors, a median nadir pH of 6.71, IQR 6.71, 6.73; survivors, a median peak

  3. Dacarbazine with or without oblimersen (a Bcl-2 antisense oligonucleotide) in chemotherapy-naive patients with advanced melanoma and low-normal serum lactate dehydrogenase: 'The AGENDA trial'.

    PubMed

    Bedikian, Agop Y; Garbe, Claus; Conry, Robert; Lebbe, Celeste; Grob, Jean J

    2014-06-01

    In a previous large randomized, open-label study, retrospective subset analysis revealed that the addition of the Bcl-2 antisense oligonucleotide oblimersen to dacarbazine (Dac) significantly improved overall survival, progression-free survival, and the response rate in chemotherapy-naive patients with advanced melanoma and normal baseline serum lactate dehydrogenase (LDH) levels. To confirm and expand on this observation, we conducted a prospective double-blind, placebo-controlled study to determine whether oblimersen augmented the efficacy of Dac in advanced melanoma patients with low-normal baseline LDH levels. A total of 314 chemotherapy-naive patients were randomly assigned to receive Dac (1000 mg/m(2)) preceded by a 5-day continuous intravenous infusion of either oblimersen sodium (7 mg/kg/day) or placebo every 21 days for less than eight cycles. Co-primary efficacy endpoints were overall survival and progression-free survival. Response and progression of the disease were assessed by independent blinded review of computed tomography scan images. No difference in overall nor progression-free survival was observed between the Dac-oblimersen and Dac-placebo groups. Although the overall (17.2 vs. 12.1%) and durable (10.8 vs. 7.6%) response rates numerically favored Dac-oblimersen over Dac-placebo, they did not differ significantly (P=0.19 and 0.32, respectively). The incidence of hematologic adverse events, particularly thrombocytopenia and neutropenia, was higher in the Dac-oblimersen group than in the Dac-placebo group. Withdrawals from the study because of treatment-related adverse events were low (i.e. <2.5%) in both groups. The addition of oblimersen to Dac did not significantly improve overall survival nor progression-free survival in patients with advanced melanoma and low-normal levels of LDH at baseline.

  4. Restraint stress in lactating mice alters the levels of sulfur-containing amino acids in milk.

    PubMed

    Nishigawa, Takuma; Nagamachi, Satsuki; Ikeda, Hiromi; Chowdhury, Vishwajit S; Furuse, Mitsuhiro

    2018-03-30

    It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring's body weight. Various causes of maternal stress during the lactation period, relating to, for example, maternal nutritional status and reduced maternal care, have been considered. However, little is known about the effects on milk of maternal stress during the lactation period. The current study aimed to determine whether free amino acids, with special reference to sulfur-containing amino acids in milk, are altered by restraint stress in lactating mice. The dams in the stress group were restrained for 30 min at postnatal days 2, 4, 6, 8, 10 and 12. Restraint stress caused a reduction in the body weight of lactating mice. The concentration of taurine and cystathionine in milk was significantly higher in the stress group, though stress did not alter their concentration in maternal plasma. The ratio of taurine concentration in milk to its concentration in maternal plasma was significantly higher in the stress group, suggesting that stress promoted taurine transportation into milk. Furthermore, taurine concentration in milk was positively correlated with corticosterone levels in plasma. In conclusion, restraint stress in lactating mice caused the changes in the metabolism and in the transportation of sulfur-containing amino acids and resulted in higher taurine concentration in milk. Taurine concentration in milk could also be a good parameter for determining stress status in dams.

  5. Lactate shuttling and lactate use as fuel after traumatic brain injury: metabolic considerations

    PubMed Central

    Dienel, Gerald A

    2014-01-01

    Lactate is proposed to be generated by astrocytes during glutamatergic neurotransmission and shuttled to neurons as ‘preferred' oxidative fuel. However, a large body of evidence demonstrates that metabolic changes during activation of living brain disprove essential components of the astrocyte–neuron lactate shuttle model. For example, some glutamate is oxidized to generate ATP after its uptake into astrocytes and neuronal glucose phosphorylation rises during activation and provides pyruvate for oxidation. Extension of the notion that lactate is a preferential fuel into the traumatic brain injury (TBI) field has important clinical implications, and the concept must, therefore, be carefully evaluated before implementation into patient care. Microdialysis studies in TBI patients demonstrate that lactate and pyruvate levels and lactate/pyruvate ratios, along with other data, have important diagnostic value to distinguish between ischemia and mitochondrial dysfunction. Results show that lactate release from human brain to blood predominates over its uptake after TBI, and strong evidence for lactate metabolism is lacking; mitochondrial dysfunction may inhibit lactate oxidation. Claims that exogenous lactate infusion is energetically beneficial for TBI patients are not based on metabolic assays and data are incorrectly interpreted. PMID:25204393

  6. Novel strategy for phenyllactic acid biosynthesis from phenylalanine by whole cell recombinant Escherichia coli coexpressing L-phenylalanine oxidase and L-lactate dehydrogenase.

    PubMed

    Zhang, Jianzhi; Li, Xi

    2018-01-01

    To enhance the efficiency of phenyllactic acid (PLA) production from L-phenylalanine (L-Phe) by introducing a novel artificial pathway into Escherichia coli RESULTS: The production of PLA from L-Phe by recombinant E. coli (ldh-lpox) coexpressing L-phenylalanine oxidase and L-lactate dehydrogenase was studied. The new PLA synthesis pathway was confirmed to be efficient in recombinant E. coli. Subsequently, two different biocatalyst processes were carried out and optimized for PLA production. In the whole cell biosynthesis process at high cell density using collected recombinant cells as catalyst, at optimal conditions (L-Phe 6 g/l, pH 7.5, 35 °C, CDW 24.5 g/l and 200 rpm), the recombinant E. coli (ldh-lpox) produced 1.62 g PLA/l with a conversion of 28% from L-Phe. Similarly, during the two-temperature-stage fermentation process in flasks using IPTG-induced cells, the temperature in the second stage was increased to 35 °C to benefit the biocatalyst process, and comparable phenyllactic acid production of 1.47 g/l was obtained from 12 g L-Phe/l. Recombinant E. coli (ldh-lpox) was efficient in PLA production realizing a high titer of several folds compared with studies using L-Phe as substrate.

  7. Increased titer and reduced lactate accumulation in recombinant retrovirus production through the down-regulation of HIF1 and PDK.

    PubMed

    Rodrigues, A F; Guerreiro, M R; Formas-Oliveira, A S; Fernandes, P; Blechert, A-K; Genzel, Y; Alves, P M; Hu, W S; Coroadinha, A S

    2016-01-01

    Many mammalian cell lines used in the manufacturing of biopharmaceuticals exhibit high glycolytic flux predominantly channeled to the production of lactate. The accumulation of lactate in culture reduces cell viability and may also decrease product quality. In this work, we engineered a HEK 293 derived cell line producing a recombinant gene therapy retroviral vector, by down-regulating hypoxia inducible factor 1 (HIF1) and pyruvate dehydrogenase kinase (PDK). Specific productivity of infectious viral titers could be increased more than 20-fold for single gene knock-down (HIF1 or PDK) and more than 30-fold under combined down-regulation. Lactate production was reduced up to 4-fold. However, the reduction in lactate production, alone, was not sufficient to enhance the titer: high-titer clones also showed significant enrollment of metabolic routes not related to lactate production. Transcriptome analysis indicated activation of biological amines metabolism, detoxification routes, including glutathione metabolism, pentose phosphate pathway, glycogen biosynthesis and amino acid catabolism. The latter were validated by enzyme activity assays and metabolite profiling, respectively. High-titer clones also presented substantially increased transcript levels of the viral genes expression cassettes. The results herein presented demonstrate the impact of HIF1 and PDK down-regulation on the production performance of a mammalian cell line, reporting one of the highest fold-increase in specific productivity of infectious virus titers achieved by metabolic engineering. They additionally highlight the contribution of secondary pathways, beyond those related to lactate production, that can be also explored to pursue improved metabolic status favoring a high-producing phenotype. © 2015 Wiley Periodicals, Inc.

  8. Characterization of the major dehydrogenase related to d-lactic acid synthesis in Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293.

    PubMed

    Li, Ling; Eom, Hyun-Ju; Park, Jung-Mi; Seo, Eunyoung; Ahn, Ji Eun; Kim, Tae-Jip; Kim, Jeong Hwan; Han, Nam Soo

    2012-10-10

    Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 is a lactic acid bacterium that converts pyruvate mainly to d-(-)-lactic acid by using d-(-)-lactate dehydrogenase (ldhD). The aim of this study was to identify the gene responsible for d-lactic acid formation in this organism and to characterize the enzyme to facilitate the production of optically pure d-lactic acid. A genomic analysis of L. mesenteroides ATCC 8293 revealed that 7 genes encode lactate-related dehydrogenase. According to transcriptomic, proteomic, and phylogenetic analyses, LEUM_1756 was the major gene responsible for the production of d-lactic acid. The LEUM_1756 gene, of 996bp and encoding 332 amino acids (36.5kDa), was cloned and overexpressed in Escherichia coli BL21(DE3) Star from an inducible pET-21a(+) vector. The enzyme was purified by Ni-NTA column chromatography and showed a specific activity of 4450U/mg, significantly higher than those of other previously reported ldhDs. The gel permeation chromatography analysis showed that the purified enzyme exists as tetramers in solution and this was the first report among lactic acid bacteria. The pH and temperature optima were pH 8.0 and 30°C, respectively, for the pyruvate reduction reaction, and pH 11.0 and 20°C, respectively, for the lactate oxidation reaction. The K(m) kinetic parameters for pyruvate and lactate were 0.58mM and 260mM, respectively. In addition, the k(cat) values for pyruvate and lactate were 2900s(-1) and 2280s(-1), respectively. The enzyme was not inhibited by Ca(2+), Co(2+), Cu(2+), Mg(2+), Mn(2+), Na(+), or urea, but was inhibited by 1mM Zn(2+) and 1mM SDS. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. [Prevalence of thyroid function in pregnant and lactating women in areas with different iodine levels of Shanxi province].

    PubMed

    Ren, Y T; Jia, Q Z; Zhang, X D; Guo, B S; Zhang, F F; Cheng, X T; Wang, Y P

    2018-05-10

    Objective: To investigate the effects of high iodine intake on thyroid function in pregnant and lactating women. Methods: A cross sectional epidemiological study was conducted among 130 pregnant women and 220 lactating women aged 19-40 years in areas with high environment iodine level (>300 μg/L) or proper environment iodine level (50-100 μg/L) in Shanxi in 2014. The general information, urine samples and blood samples of the women surveyed and water samples were collected. The water and urine iodine levels were detected with arsenic and cerium catalysis spectrophotometric method, the blood TSH level was detected with electrochemiluminescence immunoassay, and thyroid stimulating hormone (FT(4)), antithyroid peroxidase autoantibody (TPOAb) and anti-thyroglobulin antibodies (TGAb) were detected with chemiluminescence immunoassay. Results: The median urine iodine levels of the four groups were 221.9, 282.5, 814.1 and 818.6 μg/L, respectively. The median serum FT(4) of lactating women in high iodine area and proper iodine area were 12.96 and 13.22 pmol/L, and the median serum TSH was 2.45 and 2.17 mIU/L, respectively. The median serum FT(4) of pregnant women in high iodine area and proper iodine area were 14.66 and 16.16 pmol/L, and the median serum TSH was 2.13 and 1.82 mIU/L, respectively. The serum FT(4) levels were lower and the abnormal rates of serum TSH were higher in lactating women than in pregnant women in both high iodine area and proper iodine area, the difference was statistically significant (FT(4): Z =-6.677, -4.041, P <0.01; TSH: Z =8.797, 8.910, P <0.01). In high iodine area, the abnormal rate of serum FT(4) in lactating women was higher than that in pregnant women, the difference was statistically significant ( Z =7.338, P =0.007). The serum FT(4) level of lactating women in high iodine area was lower than that in proper iodine area, the difference was statistically significant ( Z =-4.687, P =0.000). In high iodine area, the median serum FT(4) in

  10. A metabolic switch in brain: glucose and lactate metabolism modulation by ascorbic acid.

    PubMed

    Castro, Maite A; Beltrán, Felipe A; Brauchi, Sebastián; Concha, Ilona I

    2009-07-01

    In this review, we discuss a novel function of ascorbic acid in brain energetics. It has been proposed that during glutamatergic synaptic activity neurons preferably consume lactate released from glia. The key to this energetic coupling is the metabolic activation that occurs in astrocytes by glutamate and an increase in extracellular [K(+)]. Neurons are cells well equipped to consume glucose because they express glucose transporters and glycolytic and tricarboxylic acid cycle enzymes. Moreover, neuronal cells express monocarboxylate transporters and lactate dehydrogenase isoenzyme 1, which is inhibited by pyruvate. As glycolysis produces an increase in pyruvate concentration and a decrease in NAD(+)/NADH, lactate and glucose consumption are not viable at the same time. In this context, we discuss ascorbic acid participation as a metabolic switch modulating neuronal metabolism between rest and activation periods. Ascorbic acid is highly concentrated in CNS. Glutamate stimulates ascorbic acid release from astrocytes. Ascorbic acid entry into neurons and within the cell can inhibit glucose consumption and stimulate lactate transport. For this switch to occur, an ascorbic acid flow is necessary between astrocytes and neurons, which is driven by neural activity and is part of vitamin C recycling. Here, we review the role of glucose and lactate as metabolic substrates and the modulation of neuronal metabolism by ascorbic acid.

  11. Effects of substitution of different levels of steam-flaked corn for finely ground corn on lactation and digestion in early lactation dairy cows.

    PubMed

    Zhong, R Z; Li, J G; Gao, Y X; Tan, Z L; Ren, G P

    2008-10-01

    Eight multiparous Holstein cows, 4 of them fitted with rumen cannulas, were used to test the effects of substitution of steam-flaked corn (SFC) for equal amounts of finely ground corn (FGC) in diets on feed intake and digestion, blood metabolites, and lactation performance in early lactation dairy cows. Cows were fed 4 diets in a replicated 4 x 4 Latin square design. The fistulated cows formed 1 replicate. Each experimental period lasted for 3 wk. The 4 diets contained 0, 10, 20, or 40% SFC and 40, 30, 20, or 0% FGC (dry matter basis), respectively. The milk protein content and yield, milk solid nonfat content and yield, plasma glucose concentration, and dry matter intake increased as the proportion of SFC increased in diets. Apparent total tract digestibilities of dry matter, organic matter, neutral detergent fiber, acid detergent fiber, and average ruminal fluid NH(3)-N concentration decreased with increasing levels of SFC. The ruminal fluid pH was not affected by the substitution of SFC for FGC. The 20% SFC substitution improved digestion of crude protein, yield of fat-corrected milk, milk lactose content, fat, and fat yield. The 40% SFC substitution increased urea concentration in both plasma and milk. It was concluded that 20% of SFC substitution for FGC appeared to be an appropriate level in diet for early lactation dairy cows.

  12. Milk trace elements in lactating cows environmentally exposed to higher level of lead and cadmium around different industrial units.

    PubMed

    Patra, R C; Swarup, D; Kumar, P; Nandi, D; Naresh, R; Ali, S L

    2008-10-01

    The present investigation was carried out to assess the trace mineral profile of milk from lactating cows reared around different industrial units and to examine the effect of blood and milk concentration of lead and cadmium on copper, cobalt, zinc and iron levels in milk. Respective blood and milk samples were collected from a total of 201 apparently healthy lactating cows above 3 years of age including 52 cows reared in areas supposed to be free from pollution. The highest milk lead (0.85+/-0.11 microg/ml) and cadmium (0.23+/-0.02 microg/ml) levels were recorded in lactating cows reared around lead-zinc smelter and steel manufacturing plant, respectively. Significantly (P<0.05) higher concentration of milk copper, cobalt, zinc and iron compared to control animals was recorded in cows around closed lead cum operational zinc smelter. Analysis of correlation between lead and other trace elements in milk from lactating cows with the blood lead level>0.20 microg/ml (n=79) revealed a significant negative correlations between milk iron and milk lead (r=-0.273, P=0.015). However, such trend was not recorded with blood lead level<0.20 microg/ml (n=122). The milk cobalt concentration was significantly correlated (r=0.365, P<0.001) with cadmium level in milk and the highest milk cadmium (>0.10 to 0.39 microg/ml) group had significantly (P<0.05) increased milk cobalt. It is concluded that increased blood and milk lead or cadmium level as a result of natural exposure of lactating cows to these environmental toxicants significantly influences trace minerals composition of milk and such alterations affect the milk quality and nutritional values.

  13. Oligosaccharide-based Surfactant/Citric Acid Buffer System Stabilizes Lactate Dehydrogenase during Freeze-drying and Storage without the Addition of Natural Sugar.

    PubMed

    Ogawa, Shigesaburo; Kawai, Ryuichiro; Koga, Maito; Asakura, Kouichi; Takahashi, Isao; Osanai, Shuichi

    2016-06-01

    Experiments were conducted to assess the maintenance effects of oligosaccharide-based surfactants on the enzymatic activity of a model protein, lactate dehydrogenase (LDH), during freeze-drying and room temperature storage using the citric acid buffer system. Oligosaccharide-based surfactants, which exhibit a high glass transition temperature (Tg), promoted the eminent retention of enzymatic activity during these protocols, whereas monosaccharide-based surfactants with a low Tg displayed poor performance at high concentration, albeit much better than that of Tween 80 at middle concentration. The increase in the alkyl chain length did not exert positive effects as observed for the maintenance effect during freeze-thawing, but an amphiphilic nature and a glass forming ability were crucial for the effective stabilization at a low excipient concentration during freeze-drying. Even a low oligosaccharide-based surfactant content (0.1 mg mL(-1)) could maintain LDH activity during freeze-drying, but a high surfactant content (1.0 mg mL(-1)) was required to prevent buffer precipitation and retain high LDH activity on storage. Regarding storage, glass formation restricted molecular mobility in the lyophilized matrix, and LDH activity was effectively retained. The present results describe a strategy based on the glass-forming ability of surfactant-type excipients that affords a natural sugar-free formulation or an alternative use for polysorbate-type surfactants.

  14. Effect of vitamin A administration on free radicals and lactate levels in individuals exercised to exhaustion.

    PubMed

    Patlar, Suleyman; Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim

    2016-09-01

    This study was performed to explore the effect of vitamin A administration on Free Radicals production and antioxidant system activity and lactate levels in individuals exercised to exhaustion The study registered 10 healthy sedentary males their mean age was 22,85±0,26 years. The subjects were orally administrated with 300 mg vitamin A (retinol) for 4 weeks and engaged in strenuous exercise (using the Bruce protocol) once a week. Blood samples were collected from the subjects at four different times, before and after the supplementation and before and after exercise to analyze Malondialdehyde (MDA), Nitric oxide (NO), Glutathione (GSH), Glutathione peroxidase (GSH-Px), Catalase (CAT), Superoxide dismutase (SOD) levels using colorimetric ELISA test kits and plasma lactate levels using an autoanalyzer. Exhaustion exercise leaded to an increase in both MDA, NO, and lactate, and GSH, GSH-Px, CAT and SOD levels compared to resting levels both before and after supplementation (p<0.05). Increased NO levels found in pre-supplementation exhaustion showed a significant decrease after the supplementation of vitamin A (p<0.05), but the other parameters were not changed after vitamin A administration. The results of our study demonstrate that the increase caused by 4-week strenuous exercise in the levels of the free radical NO was offset by vitamin A supplementation. It can be suggested that supplementation of vitamin A at physiological doses has a limited effect on lipid peroxidation caused by strenuous exercise.

  15. Novel model of neuronal bioenergetics: postsynaptic utilization of glucose but not lactate correlates positively with Ca2+ signalling in cultured mouse glutamatergic neurons

    PubMed Central

    Bak, Lasse K.; Obel, Linea F.; Walls, Anne B.; Schousboe, Arne; Faek, Sevan A.A.; Jajo, Farah S.; Waagepetersen, Helle S.

    2012-01-01

    We have previously investigated the relative roles of extracellular glucose and lactate as fuels for glutamatergic neurons during synaptic activity. The conclusion from these studies was that cultured glutamatergic neurons utilize glucose rather than lactate during NMDA (N-methyl-d-aspartate)-induced synaptic activity and that lactate alone is not able to support neurotransmitter glutamate homoeostasis. Subsequently, a model was proposed to explain these results at the cellular level. In brief, the intermittent rises in intracellular Ca2+ during activation cause influx of Ca2+ into the mitochondrial matrix thus activating the tricarboxylic acid cycle dehydrogenases. This will lead to a lower activity of the MASH (malate–aspartate shuttle), which in turn will result in anaerobic glycolysis and lactate production rather than lactate utilization. In the present work, we have investigated the effect of an ionomycin-induced increase in intracellular Ca2+ (i.e. independent of synaptic activity) on neuronal energy metabolism employing 13C-labelled glucose and lactate and subsequent mass spectrometric analysis of labelling in glutamate, alanine and lactate. The results demonstrate that glucose utilization is positively correlated with intracellular Ca2+ whereas lactate utilization is not. This result lends further support for a significant role of glucose in neuronal bioenergetics and that Ca2+ signalling may control the switch between glucose and lactate utilization during synaptic activity. Based on the results, we propose a compartmentalized CiMASH (Ca2+-induced limitation of the MASH) model that includes intracellular compartmentation of glucose and lactate metabolism. We define pre- and post-synaptic compartments metabolizing glucose and glucose plus lactate respectively in which the latter displays a positive correlation between oxidative metabolism of glucose and Ca2+ signalling. PMID:22385215

  16. Characterization of lactate utilization and its implication on the physiology of Haemophilus influenzae.

    PubMed

    Lichtenegger, Sabine; Bina, Isabelle; Roier, Sandro; Bauernfeind, Stilla; Keidel, Kristina; Schild, Stefan; Anthony, Mark; Reidl, Joachim

    2014-05-01

    Haemophilus influenzae is a Gram-negative bacillus and a frequent commensal of the human nasopharynx. Earlier work demonstrated that in H. influenzae type b, l-lactate metabolism is associated with serum resistance and in vivo survival of the organism. To further gain insight into lactate utilization of the non-typeable (NTHi) isolate 2019 and laboratory prototype strain Rd KW20, deletion mutants of the l-lactate dehydrogenase (lctD) and permease (lctP) were generated and characterized. It is shown, that the apparent KM of l-lactate uptake is 20.1μM as determined for strain Rd KW20. Comparison of the COPD isolate NTHi 2019-R with the corresponding lctP knockout strain for survival in human serum revealed no lactate dependent serum resistance. In contrast, we observed a 4-fold attenuation of the mutant strain in a murine model of nasopharyngeal colonization. Characterization of lctP transcriptional control shows that the lactate utilization system in H. influenzae is not an inductor inducible system. Rather negative feedback regulation was observed in the presence of l-lactate and this is dependent on the ArcAB regulatory system. Additionally, for 2019 it was found that lactate may have signaling function leading to increased cell growth in late log phase under conditions where no l-lactate is metabolized. This effect seems to be ArcA independent and was not observed in strain Rd KW20. We conclude that l-lactate is an important carbon-source and may act as host specific signal substrate which fine tunes the globally acting ArcAB regulon and may additionally affect a yet unknown signaling system and thus may contribute to enhanced in vivo survival. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. Disruption of lactate dehydrogenase and alcohol dehydrogenase for increased hydrogen production and its effect on metabolic flux in Enterobacter aerogenes.

    PubMed

    Zhao, Hongxin; Lu, Yuan; Wang, Liyan; Zhang, Chong; Yang, Cheng; Xing, Xinhui

    2015-10-01

    Hydrogen production by Enterobacter aerogenes from glucose was enhanced by deleting the targeted ldhA and adh genes responsible for two NADH-consuming pathways which consume most NADH generated from glycolysis. Compared with the wild-type, the hydrogen yield of IAM1183-ΔldhA increased 1.5 fold. Metabolic flux analysis showed both IAM1183-ΔldhA and IAM1183-Δadh exhibited significant changes in flux, including enhanced flux towards the hydrogen generation. The lactate production of IAM1183-ΔldhA significantly decreased by 91.42%, while the alcohol yield of IAM1183-Δadh decreased to 30%. The mutant IAM1183-ΔldhA with better hydrogen-producing performance was selected for further investigation in a 5-L fermentor. The hydrogen production of IAM1183-ΔldhA was 2.3 times higher than the wild-type. Further results from the fermentation process showed that the pH decreased to 5.39 levels, then gradually increased to 5.96, indicating that some acidic metabolites might be degraded or uptaken by cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Hepatic lipidosis in anorectic, lactating holstein cattle: a retrospective study of serum biochemical abnormalities.

    PubMed

    Cebra, C K; Garry, F B; Getzy, D M; Fettman, M J

    1997-01-01

    The association between hepatic lipidosis (HL) and disease in 59 anorectic, ketotic, lactating Holstein heifers and cows was investigated. Severe HL, as determined by histologic evaluation of liver tissue, was present in 46 animals; only half of these animals required intensive treatment for ketosis, and only half had serum biochemical evidence of liver disease, as determined by the presence of a last value of 2-fold or greater than the upper limit of the reference ranges for at least 2 of the 4 serum tests: gamma-glutamyl transferase, aspartate aminotransferase, and sorbitol dehydrogenase activities and bile acid concentrations. Most cattle with biochemical evidence of liver disease and severe HL had been lactating for 14 or more days. Cows that required intensive treatment inconsistently had serum biochemical evidence of liver disease. Although cattle with severe HL had significantly higher serum bilirubin concentrations and aspartate aminotransferase and sorbitol dehydrogenase activities than cattle with less severe lipidosis, the specificity of abnormally high serum sorbitol dehydrogenase activity or bilirubin concentration for severe lipidosis was only 8%. Abnormally high serum aspartate aminotransferase activity was 83% sensitive and 62% specific for severe lipidosis. Serum glucose and total carbon dioxide concentrations were significantly lower in cattle with severe lipidosis than in those with mild or moderate lipidosis, and low serum glucose or total carbon dioxide concentrations were rare in cattle without severe lipidosis. From these data, we conclude that the use of a single biochemical or histopathologic criterion to define severity of disease or degree of liver compromise in anorectic, ketotic cows results in the misidentification of many animals.

  19. The intrinsically disordered protein LEA7 from Arabidopsis thaliana protects the isolated enzyme lactate dehydrogenase and enzymes in a soluble leaf proteome during freezing and drying.

    PubMed

    Popova, Antoaneta V; Rausch, Saskia; Hundertmark, Michaela; Gibon, Yves; Hincha, Dirk K

    2015-10-01

    The accumulation of Late Embryogenesis Abundant (LEA) proteins in plants is associated with tolerance against stresses such as freezing and desiccation. Two main functions have been attributed to LEA proteins: membrane stabilization and enzyme protection. We have hypothesized previously that LEA7 from Arabidopsis thaliana may stabilize membranes because it interacts with liposomes in the dry state. Here we show that LEA7, contrary to this expectation, did not stabilize liposomes during drying and rehydration. Instead, it partially preserved the activity of the enzyme lactate dehydrogenase (LDH) during drying and freezing. Fourier-transform infrared (FTIR) spectroscopy showed no evidence of aggregation of LDH in the dry or rehydrated state under conditions that lead to complete loss of activity. To approximate the complex influence of intracellular conditions on the protective effects of a LEA protein in a convenient in-vitro assay, we measured the activity of two Arabidopsis enzymes (glucose-6-P dehydrogenase and ADP-glucose pyrophosphorylase) in total soluble leaf protein extract (Arabidopsis soluble proteome, ASP) after drying and rehydration or freezing and thawing. LEA7 partially preserved the activity of both enzymes under these conditions, suggesting its role as an enzyme protectant in vivo. Further FTIR analyses indicated the partial reversibility of protein aggregation in the dry ASP during rehydration. Similarly, aggregation in the dry ASP was strongly reduced by LEA7. In addition, mixtures of LEA7 with sucrose or verbascose reduced aggregation more than the single additives, presumably through the effects of the protein on the H-bonding network of the sugar glasses. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Karnofsky Performance Status and Lactate Dehydrogenase Predict the Benefit of Palliative Whole-Brain Irradiation in Patients With Advanced Intra- and Extracranial Metastases From Malignant Melanoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Partl, Richard, E-mail: richard.partl@medunigraz.at; Richtig, Erika; Avian, Alexander

    2013-03-01

    Purpose: To determine prognostic factors that allow the selection of melanoma patients with advanced intra- and extracerebral metastatic disease for palliative whole-brain radiation therapy (WBRT) or best supportive care. Methods and Materials: This was a retrospective study of 87 patients who underwent palliative WBRT between 1988 and 2009 for progressive or multiple cerebral metastases at presentation. Uni- and multivariate analysis took into account the following patient- and tumor-associated factors: gender and age, Karnofsky performance status (KPS), neurologic symptoms, serum lactate dehydrogenase (LDH) level, number of intracranial metastases, previous resection or stereotactic radiosurgery of brain metastases, number of extracranial metastasis sites,more » and local recurrences as well as regional lymph node metastases at the time of WBRT. Results: In univariate analysis, KPS, LDH, number of intracranial metastases, and neurologic symptoms had a significant influence on overall survival. In multivariate survival analysis, KPS and LDH remained as significant prognostic factors, with hazard ratios of 3.3 (95% confidence interval [CI] 1.6-6.5) and 2.8 (95% CI 1.6-4.9), respectively. Patients with KPS ≥70 and LDH ≤240 U/L had a median survival of 191 days; patients with KPS ≥70 and LDH >240 U/L, 96 days; patients with KPS <70 and LDH ≤240 U/L, 47 days; and patients with KPS <70 and LDH >240 U/L, only 34 days. Conclusions: Karnofsky performance status and serum LDH values indicate whether patients with advanced intra- and extracranial tumor manifestations are candidates for palliative WBRT or best supportive care.« less

  1. Striking differences in glucose and lactate levels between brain extracellular fluid and plasma in conscious human subjects: effects of hyperglycemia and hypoglycemia.

    PubMed

    Abi-Saab, Walid M; Maggs, David G; Jones, Tim; Jacob, Ralph; Srihari, Vinod; Thompson, James; Kerr, David; Leone, Paola; Krystal, John H; Spencer, Dennis D; During, Matthew J; Sherwin, Robert S

    2002-03-01

    Brain levels of glucose and lactate in the extracellular fluid (ECF), which reflects the environment to which neurons are exposed, have never been studied in humans under conditions of varying glycemia. The authors used intracerebral microdialysis in conscious human subjects undergoing electrophysiologic evaluation for medically intractable epilepsy and measured ECF levels of glucose and lactate under basal conditions and during a hyperglycemia-hypoglycemia clamp study. Only measurements from nonepileptogenic areas were included. Under basal conditions, the authors found the metabolic milieu in the brain to be strikingly different from that in the circulation. In contrast to plasma, lactate levels in brain ECF were threefold higher than glucose. Results from complementary studies in rats were consistent with the human data. During the hyperglycemia-hypoglycemia clamp study the relationship between plasma and brain ECF levels of glucose remained similar, but changes in brain ECF glucose lagged approximately 30 minutes behind changes in plasma. The data demonstrate that the brain is exposed to substantially lower levels of glucose and higher levels of lactate than those in plasma; moreover, the brain appears to be a site of significant anaerobic glycolysis, raising the possibility that glucose-derived lactate is an important fuel for the brain.

  2. Human mesenchymal stromal cell-secreted lactate induces M2-macrophage differentiation by metabolic reprogramming

    PubMed Central

    Civini, Sara; Pacelli, Consiglia; Dieng, Mame Massar; Lemieux, William; Jin, Ping; Bazin, Renée; Patey, Natacha; Marincola, Francesco M.; Moldovan, Florina; Zaouter, Charlotte; Trudeau, Louis-Eric; Benabdhalla, Basma; Louis, Isabelle; Beauséjour, Christian; Stroncek, David; Le Deist, Françoise; Haddad, Elie

    2016-01-01

    Human mesenchymal stromal cells (MSC) have been shown to dampen immune response and promote tissue repair, but the underlying mechanisms are still under investigation. Herein, we demonstrate that umbilical cord-derived MSC (UC-MSC) alter the phenotype and function of monocyte-derived dendritic cells (DC) through lactate-mediated metabolic reprogramming. UC-MSC can secrete large quantities of lactate and, when present during monocyte-to-DC differentiation, induce instead the acquisition of M2-macrophage features in terms of morphology, surface markers, migratory properties and antigen presentation capacity. Microarray expression profiling indicates that UC-MSC modify the expression of metabolic-related genes and induce a M2-macrophage expression signature. Importantly, monocyte-derived DC obtained in presence of UC-MSC, polarize naïve allogeneic CD4+ T-cells into Th2 cells. Treatment of UC-MSC with an inhibitor of lactate dehydrogenase strongly decreases lactate concentration in culture supernatant and abrogates the effect on monocyte-to-DC differentiation. Metabolic analysis further revealed that UC-MSC decrease oxidative phosphorylation in differentiating monocytes while strongly increasing the spare respiratory capacity proportional to the amount of secreted lactate. Because both MSC and monocytes are recruited in vivo at the site of tissue damage and inflammation, we propose the local increase of lactate concentration induced by UC-MSC and the consequent enrichment in M2-macrophage generation as a mechanism to achieve immunomodulation. PMID:27070086

  3. Multiple e-pharmacophore modelling pooled with high-throughput virtual screening, docking and molecular dynamics simulations to discover potential inhibitors of Plasmodium falciparum lactate dehydrogenase (PfLDH).

    PubMed

    Saxena, Shalini; Durgam, Laxman; Guruprasad, Lalitha

    2018-05-14

    Development of new antimalarial drugs continues to be of huge importance because of the resistance of malarial parasite towards currently used drugs. Due to the reliance of parasite on glycolysis for energy generation, glycolytic enzymes have played important role as potential targets for the development of new drugs. Plasmodium falciparum lactate dehydrogenase (PfLDH) is a key enzyme for energy generation of malarial parasites and is considered to be a potential antimalarial target. Presently, there are nearly 15 crystal structures bound with inhibitors and substrate that are available in the protein data bank (PDB). In the present work, we attempted to consider multiple crystal structures with bound inhibitors showing affinity in the range of 1.4 × 10 2 -1.3 × 10 6  nM efficacy and optimized the pharmacophore based on the energy involved in binding termed as e-pharmacophore mapping. A high throughput virtual screening (HTVS) combined with molecular docking, ADME predictions and molecular dynamics simulation led to the identification of 20 potential compounds which could be further developed as novel inhibitors for PfLDH.

  4. Dinosaur lactation?

    PubMed

    Else, Paul L

    2013-02-01

    Lactation is a process associated with mammals, yet a number of birds feed their newly hatched young on secretions analogous to the milk of mammals. These secretions are produced from various sections (crop organ, oesophageal lining and proventriculus) of the upper digestive tract and possess similar levels of fat and protein, as well as added carotenoids, antibodies and, in the case of pigeons and doves, epidermal growth factor. Parental care in avian species has been proposed to originate from dinosaurs. This study examines the possibility that some dinosaurs used secretory feeding to increase the rate of growth of their young, estimated to be similar to that of present day birds and mammals. Dinosaur 'lactation' could also have facilitated immune responses as well as extending parental protection as a result of feeding newly hatched young in nest environments. While the arguments for dinosaur lactation are somewhat generic, a case study for lactation in herbivorous site-nesting dinosaurs is presented. It is proposes that secretory feeding could have been used to bridge the gap between hatching and establishment of the normal diet in some dinosaurs.

  5. Clinical utility of serum lactate levels for differential diagnosis of generalized tonic-clonic seizures from psychogenic nonepileptic seizures and syncope.

    PubMed

    Doğan, Ebru Apaydın; Ünal, Ali; Ünal, Aslıhan; Erdoğan, Çağla

    2017-10-01

    The differential diagnosis of generalized tonic-clonic seizures (GTCS), psychogenic nonepileptic seizures (PNES), and syncope constitutes a major challenge. Misdiagnosis rates up to 20 to 30% are reported in the literature. To assess the clinical utility of serum lactate levels for differentiation of GTCS, PNES, and syncope based on gender differences. Data from 270 patients were evaluated retrospectively. Only patients ≥18 years old with the final diagnosis of GTCS, PNES, or syncope in their chart were recruited. Serum lactate levels were measured in the first 2h of the index event. Serum lactate levels in patients with GTCS (n=157) were significantly higher than in the patients with PNES (n=25) (p<0.001) and syncope (n=88) (p<0.001). When compared with the females, serum lactate levels in patients with GTCS were significantly higher in the male subgroup (p=0.004). In male patients the ROC analysis yielded a serum lactate value of 2.43mmol/l with a sensitivity of 0.85 and a specificity of 0.88 as the optimal cut-off value to distinguish GTCS from other events. The ROC analysis for the AUC yielded a high estimate of 0.94 (95% confidence interval: 0.91-0.98). When a cut-off value of 2.43mmol/l was chosen for the females, which was an optimal value for male patients, the specificity was 0.85, however, the sensitivity was 0.64. We propose that serum lactate level when measured in the first 2h after the index event has a high clinical utility in the differential diagnosis of GTCS, PNES, and syncope. With concomitant clinical signs and physical examination findings besides neuroimaging and EEG, elevated levels of lactate should be taken into account when evaluating a patient with impaired consciousness. On the other hand, the suggested cut-off value 2.43mmol/l might not have a discriminative effect between GTCS, PNES, and syncope in female patients. This finding should be verified in a prospectively designed study with a larger patient population. Copyright © 2017

  6. Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy/chronic fatigue syndrome

    PubMed Central

    Mella, Olav; Bruland, Ove; Risa, Kristin; Dyrstad, Sissel E.; Alme, Kine; Rekeland, Ingrid G.; Sapkota, Dipak; Røsland, Gro V.; Fosså, Alexander; Ktoridou-Valen, Irini; Lunde, Sigrid; Sørland, Kari; Lien, Katarina; Herder, Ingrid; Thürmer, Hanne; Gotaas, Merete E.; Baranowska, Katarzyna A.; Bohnen, Louis M.L.J.; Schäfer, Christoph; McCann, Adrian; Sommerfelt, Kristian; Helgeland, Lars; Ueland, Per M.; Dahl, Olav

    2016-01-01

    Myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is a debilitating disease of unknown etiology, with hallmark symptoms including postexertional malaise and poor recovery. Metabolic dysfunction is a plausible contributing factor. We hypothesized that changes in serum amino acids may disclose specific defects in energy metabolism in ME/CFS. Analysis in 200 ME/CFS patients and 102 healthy individuals showed a specific reduction of amino acids that fuel oxidative metabolism via the TCA cycle, mainly in female ME/CFS patients. Serum 3-methylhistidine, a marker of endogenous protein catabolism, was significantly increased in male patients. The amino acid pattern suggested functional impairment of pyruvate dehydrogenase (PDH), supported by increased mRNA expression of the inhibitory PDH kinases 1, 2, and 4; sirtuin 4; and PPARδ in peripheral blood mononuclear cells from both sexes. Myoblasts grown in presence of serum from patients with severe ME/CFS showed metabolic adaptations, including increased mitochondrial respiration and excessive lactate secretion. The amino acid changes could not be explained by symptom severity, disease duration, age, BMI, or physical activity level among patients. These findings are in agreement with the clinical disease presentation of ME/CFS, with inadequate ATP generation by oxidative phosphorylation and excessive lactate generation upon exertion. PMID:28018972

  7. Bio-Physicochemical Interactions of Engineered Nanomaterials in in Vitro Cell Culture Model

    DTIC Science & Technology

    2014-10-11

    are the important factors to study their toxicity . To investigate the potential role of oxidative stress as a mechanism of toxicity , reactive oxygen...of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO) lactate dehydrogenase (LDH) level and reduction in...potential role of oxidative stress as a mechanism of toxicity , reactive oxygen species (ROS), nitric oxide (NO), lactate dehydrogenase (LDH) level

  8. The Effects of Direct Oxygen Supply During Static Cold Preservation of Rat Livers: An Experimental Study.

    PubMed

    Zumrutdal, Emin; Karateke, Faruk; Eser, Pınar Eylem; Turan, Umit; Ozyazici, Sefa; Sozutek, Alper; Gulkaya, Mustafa; Kunt, Mevlut

    2016-12-01

    We aimed to determine the biochemical and histopathologic effects of direct oxygen supply to the preservation fluid of static cold storage system with a simple method on rat livers. Sixteen rats were randomly divided into 2 groups: the control group, which contained Ringer's lactate as preservation fluid; and the oxygen group, which contained oxygen and Ringer's lactate for preservation. Each liver was placed in a bag containing 50 mL Ringer's lactate and placed in ice-filled storage containers. One hundred percent oxygen supplies were given via a simple, inexpensive system created in our laboratory, to the livers in oxygen group. We obtained samples for histopathologic evaluation in the 12th hour. In addition, 3 mL of preservation fluid was subjected to biochemical analysis at 0, sixth, and twelfth hours. Aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and pH levels were measured from the preservation fluid. In oxygen-supplemented group, the acceleration speed of increase in alanine aminotransferase and lactate dehydrogenase levels at sixth hour and lactate dehydrogenase, alanine aminotransferase, and lactate dehydrogenase levels at 12th hour were statistically significantly reduced. In histopathologic examination, all parameters except ballooning were statistically significantly better in the oxygen-supplemented group. This simple system for oxygenation of liver tissues during static cold storage was shown to be effective with good results in biochemical and histopathologic assessments. Because this is a simple, inexpensive, and easily available method, larger studies are warranted to evaluate its effects (especially in humans).

  9. The investigation of plasma glucose-6-phosphate dehydrogenase, 6-phoshogluconate dehydrogenase, glutathione reductase in premenauposal patients with iron deficiency anemia.

    PubMed

    Ozcicek, Fatih; Aktas, Mehmet; Türkmen, Kultigin; Coban, T Abdulkadir; Cankaya, Murat

    2014-07-01

    Iron is an essential element that is necessary for all cells in the body. Iron deficiency anemia (IDA) is one of the most common nutritional disorders in both developed and developing countries. The glutathione pathway is paramount to antioxidant defense and glucose-6-phosphate dehydrogenase (G6PD)-deficient cells do not cope well with oxidative damage. The goal of this study was to check the activities of G6PD, 6-phosphogluconate dehydrogenase, glutathione reductase in patients with IDA. We analyzed the plasma samples of 102 premenopausal women with IDA and 88 healthy control subjects. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activity as compared to the reduction of NADP +, glutathione reductase activity was performed based on the oxidation of NADPH. 2 ml of plasma were used in all analyzes. SPSS program was used for all of the statistical analysis. Diagnosis of iron deficiency in patients belonging to the analysis of blood were ferritin 3.60 ± 2.7 ng / mL, hemoglobin 9.4 ± 1.5 mg / dl and hematocrit 30.7 ± 4.1% ratio; in healthy subjects ferritin 53.5 ± 41.7 ng/ml, hemoglobin level 13.9 ± 1.3 mg / dl and hematocrit ratio 42 ± 3.53%. When compared to healthy subjects the glutathione reductase level (P<0.001) was found to be significantly higher in patients with IDA. IDA patients with moderate and severe anemia had lower GR activity when compared to IDA patients with mild anemia. But the plasma levels of glucose-6-phosphate dehydrogenase (P<0,600) and 6-phosphogluconate dehydrogenase (P<0,671) did not show any differences between healthy subjects and in patients with IDA. It was shown that Glucose-6-Phosphate Dehydrogenase and 6-Phosphogluconate Dehydrogenase have no effect on iron-deficiency anemia in patients. The plasma GR levels of premenopausal women with IDA were found to be higher compared to healthy subjects, which could be secondary to erythrocyte protection against oxidative stress being commonly seen in IDA.

  10. Overcoming cetuximab resistance in Ewing's sarcoma by inhibiting lactate dehydrogenase-A.

    PubMed

    Fu, Jiaxin; Jiang, Han; Wu, Chenxuan; Jiang, Yi; Xiao, Lianping; Tian, Yonggang

    2016-07-01

    Ewing's sarcoma, the second most common type of malignant bone tumor, generally occurs in children and young adults. The current treatment of Ewing's sarcoma comprises systemic anti‑cancer chemotherapy with complete surgical resection. However, the majority of patients with Ewing's sarcoma develop resistance to chemotherapy. The present study revealed an oncogenic role of lactate dehydrogenase‑A (LDHA) in the resistance of Ewing's sarcoma to cetuximab. LDHA was shown to be upregulated at the protein and mRNA level in cetuximab‑resistant Ewing's sarcoma tissues and a cell line. In addition, a link between LDHA‑induced glycolysis and cetuximab resistance in Ewing's sarcoma cells was revealed. Of note, inhibition of LDHA by either small interfering RNA or LDHA inhibitor oxamate significantly re‑sensitized cetuximab‑resistant cells to cetuximab. Combined treatment with LDHA inhibitor and cetuximab synergistically reduced the viability of cetuximab-resistant cells through the suppression of LDHA. The present study revealed a novel mechanism of cetuximab resistance from the perspective of cancer‑cell metabolism and provided a sensitization approach, which may aid in the development of anti-chemoresistance strategies for the treatment of cetuximab-resistant Ewing's sarcoma.

  11. Efficient production of optically pure D-lactic acid from raw corn starch by using a genetically modified L-lactate dehydrogenase gene-deficient and alpha-amylase-secreting Lactobacillus plantarum strain.

    PubMed

    Okano, Kenji; Zhang, Qiao; Shinkawa, Satoru; Yoshida, Shogo; Tanaka, Tsutomu; Fukuda, Hideki; Kondo, Akihiko

    2009-01-01

    In order to achieve direct and efficient fermentation of optically pure D-lactic acid from raw corn starch, we constructed L-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum and introduced a plasmid encoding Streptococcus bovis 148 alpha-amylase (AmyA). The resulting strain produced only D-lactic acid from glucose and successfully expressed amyA. With the aid of secreting AmyA, direct D-lactic acid fermentation from raw corn starch was accomplished. After 48 h of fermentation, 73.2 g/liter of lactic acid was produced with a high yield (0.85 g per g of consumed sugar) and an optical purity of 99.6%. Moreover, a strain replacing the ldhL1 gene with an amyA-secreting expression cassette was constructed. Using this strain, direct D-lactic acid fermentation from raw corn starch was accomplished in the absence of selective pressure by antibiotics. This is the first report of direct D-lactic acid fermentation from raw starch.

  12. Efficient Production of Optically Pure d-Lactic Acid from Raw Corn Starch by Using a Genetically Modified l-Lactate Dehydrogenase Gene-Deficient and α-Amylase-Secreting Lactobacillus plantarum Strain▿

    PubMed Central

    Okano, Kenji; Zhang, Qiao; Shinkawa, Satoru; Yoshida, Shogo; Tanaka, Tsutomu; Fukuda, Hideki; Kondo, Akihiko

    2009-01-01

    In order to achieve direct and efficient fermentation of optically pure d-lactic acid from raw corn starch, we constructed l-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum and introduced a plasmid encoding Streptococcus bovis 148 α-amylase (AmyA). The resulting strain produced only d-lactic acid from glucose and successfully expressed amyA. With the aid of secreting AmyA, direct d-lactic acid fermentation from raw corn starch was accomplished. After 48 h of fermentation, 73.2 g/liter of lactic acid was produced with a high yield (0.85 g per g of consumed sugar) and an optical purity of 99.6%. Moreover, a strain replacing the ldhL1 gene with an amyA-secreting expression cassette was constructed. Using this strain, direct d-lactic acid fermentation from raw corn starch was accomplished in the absence of selective pressure by antibiotics. This is the first report of direct d-lactic acid fermentation from raw starch. PMID:19011066

  13. Poliomyelitis in MuLV-infected ICR-SCID mice after injection of basement membrane matrix contaminated with lactate dehydrogenase-elevating virus.

    PubMed

    Carlson Scholz, Jodi A; Garg, Rohit; Compton, Susan R; Allore, Heather G; Zeiss, Caroline J; Uchio, Edward M

    2011-10-01

    The arterivirus lactate dehydrogenase-elevating virus (LDV) causes life-long viremia in mice. Although LDV infection generally does not cause disease, infected mice that are homozygous for the Fv1(n) allele are prone to develop poliomyelitis when immunosuppressed, a condition known as age-dependent poliomyelitis. The development of age-dependent poliomyelitis requires coinfection with endogenous murine leukemia virus. Even though LDV is a common contaminant of transplantable tumors, clinical signs of poliomyelitis after inadvertent exposure to LDV have not been described in recent literature. In addition, LDV-induced poliomyelitis has not been reported in SCID or ICR mice. Here we describe the occurrence of poliomyelitis in ICR-SCID mice resulting from injection of LDV-contaminated basement membrane matrix. After exposure to LDV, a subset of mice presented with clinical signs including paresis, which was associated with atrophy of the hindlimb musculature, and tachypnea; in addition, some mice died suddenly with or without premonitory signs. Mice presenting within the first 6 mo after infection had regions of spongiosis, neuronal necrosis and astrocytosis of the ventral spinal cord, and less commonly, brainstem. Axonal degeneration of ventral roots prevailed in more chronically infected mice. LDV was identified by RT-PCR in 12 of 15 mice with typical neuropathology; positive antiLDV immunolabeling was identified in all PCR-positive animals (n = 7) tested. Three of 8 mice with neuropathology but no clinical signs were LDV negative by RT-PCR. RT-PCR yielded murine leukemia virus in spinal cords of all mice tested, regardless of clinical presentation or neuropathology.

  14. Dynamic Changes in Cytosolic ATP Levels in Cultured Glutamatergic Neurons During NMDA-Induced Synaptic Activity Supported by Glucose or Lactate.

    PubMed

    Lange, Sofie C; Winkler, Ulrike; Andresen, Lars; Byhrø, Mathilde; Waagepetersen, Helle S; Hirrlinger, Johannes; Bak, Lasse K

    2015-12-01

    We have previously shown that synaptic transmission fails in cultured neurons in the presence of lactate as the sole substrate. Thus, to test the hypothesis that the failure of synaptic transmission is a consequence of insufficient energy supply, ATP levels were monitored employing the ATP biosensor Ateam1.03YEMK. While inducing synaptic activity by subjecting cultured neurons to two 30 s pulses of NMDA (30 µM) with a 4 min interval, changes in relative ATP levels were measured in the presence of lactate (1 mM), glucose (2.5 mM) or the combination of the two. ATP levels reversibly declined following NMDA-induced neurotransmission activity, as indicated by a reversible 10-20 % decrease in the response of the biosensor. The responses were absent when the NMDA receptor antagonist memantine was present. In the presence of lactate alone, the ATP response dropped significantly more than in the presence of glucose following the 2nd pulse of NMDA (approx. 10 vs. 20 %). Further, cytosolic Ca(2+) homeostasis during NMDA-induced synaptic transmission is partially inhibited by verapamil indicating that voltage-gated Ca(2+) channels are activated. Lastly, we showed that cytosolic Ca(2+) homeostasis is supported equally well by both glucose and lactate, and that a pulse of NMDA causes accumulation of Ca(2+) in the mitochondrial matrix. In summary, we have shown that ATP homeostasis during neurotransmission activity in cultured neurons is supported by both glucose and lactate. However, ATP homeostasis seems to be negatively affected by the presence of lactate alone, suggesting that glucose is needed to support neuronal energy metabolism during activation.

  15. Prognosis of patients excluded by the definition of septic shock based on their lactate levels after initial fluid resuscitation: a prospective multi-center observational study.

    PubMed

    Ko, Byuk Sung; Kim, Kyuseok; Choi, Sung-Hyuk; Kang, Gu Hyun; Shin, Tae Gun; Jo, You Hwan; Ryoo, Seung Mok; Beom, Jin Ho; Kwon, Woon Yong; Han, Kap Su; Choi, Han Sung; Chung, Sung Phil; Suh, Gil Joon; Lim, Tae Ho; Kim, Won Young

    2018-02-24

    Septic shock can be defined both by the presence of hyperlactatemia and need of vasopressors. Lactate levels should be measured after volume resuscitation (as per the Sepsis-3 definition). However, currently, no studies have evaluated patients who have been excluded by the new criteria for septic shock. The aim of this study was to determine the clinical characteristics and prognosis of these patients, based on their lactate levels after initial fluid resuscitation. This observational study was performed using a prospective, multi-center registry of septic shock, with the participation of 10 hospitals in the Korean Shock Society, between October 2015 and February 2017. We compared the 28-day mortality between patients who were excluded from the new definition (defined as lactate level <2 mmol/L after volume resuscitation) and those who were not (≥2 mmol/L after volume resuscitation), from among a cohort of patients with refractory hypotension, and requiring the use of vasopressors. Other outcome variables such as in-hospital mortality, intensive care unit (ICU) stay (days), Sequential Organ Failure Assessment (SOFA) scores and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were also analyzed. Of 567 patients with refractory hypotension, requiring the use of vasopressors, 435 had elevated lactate levels, while 83 did not have elevated lactate levels (either initially or after volume resuscitation), and 49 (8.2%) had elevated lactate levels initially, which normalized after fluid resuscitation. Thus, these 49 patients were excluded by the new definition of septic shock. These patients, in whom perfusion was restored, demonstrated significantly lower age, platelet count, and initial and subsequent lactate levels (all p < 0.01). Similarly, significantly lower 28-day mortality was observed in these patients than in those who had not been excluded (8.2% vs 25.5%, p = 0.02). In-hospital mortality and the maximum SOFA score were also

  16. Alcohol Dehydrogenase and Ethanol in the Stems of Trees 1

    PubMed Central

    Kimmerer, Thomas W.; Stringer, Mary A.

    1988-01-01

    Anaerobic fermentation in plants is usually thought to be a transient phenomenon, brought about by environmental limitations to oxygen availability, or by structural constraints to oxygen transport. The vascular cambium of trees is separated from the air by the outer bark and secondary phloem, and we hypothesized that the cambium may experience sufficient hypoxia to induce anaerobic fermentation. We found high alcohol dehydrogenase activity in the cambium of several tree species. Mean activity of alcohol dehydrogenase in Populus deltoides was 165 micromoles NADH oxidized per minute per gram fresh weight in May. Pyruvate decarboxylase activity was also present in the cambium of P. deltoides, with mean activity of 26 micromoles NADH oxidized per minute per gram fresh weight in May. Lactate dehydrogenase activity was not present in any tree species we examined. Contrary to our expectation, alcohol dehydrogenase activity was inversely related to bark thickness in Acer saccharum and unrelated to bark thickness in two Populus species. Bark thickness may be less important in limiting oxygen availability to the cambium than is oxygen consumption by rapidly respiring phloem and cambium in actively growing trees. Ethanol was present in the vascular cambium of all species examined, with mean concentrations of 35 to 143 nanomoles per gram fresh weight, depending on species. Ethanol was also present in xylem sap and may have been released from the cambium into the transpiration stream. The presence in the cambium of the enzymes necessary for fermentation as well as the products of fermentation is evidence that respiration in the vascular cambium of trees may be oxygen-limited, but other biosynthetic origins of ethanol have not been ruled out. PMID:16666209

  17. Lactate Test

    MedlinePlus

    ... by cells as the body turns food into energy (cell metabolism). Depending on pH , it is sometimes ... level or when the primary way of producing energy in the body's cells is disrupted. Excess lactate ...

  18. Cumulative lactate and hospital mortality in ICU patients

    PubMed Central

    2013-01-01

    Background Both hyperlactatemia and persistence of hyperlactatemia have been associated with bad outcome. We compared lactate and lactate-derived variables in outcome prediction. Methods Retrospective observational study. Case records from 2,251 consecutive intensive care unit (ICU) patients admitted between 2001 and 2007 were analyzed. Baseline characteristics, all lactate measurements, and in-hospital mortality were recorded. The time integral of arterial blood lactate levels above the upper normal threshold of 2.2 mmol/L (lactate-time-integral), maximum lactate (max-lactate), and time-to-first-normalization were calculated. Survivors and nonsurvivors were compared and receiver operating characteristic (ROC) analysis were applied. Results A total of 20,755 lactate measurements were analyzed. Data are srpehown as median [interquartile range]. In nonsurvivors (n = 405) lactate-time-integral (192 [0–1881] min·mmol/L) and time-to-first normalization (44.0 [0–427] min) were higher than in hospital survivors (n = 1846; 0 [0–134] min·mmol/L and 0 [0–75] min, respectively; all p < 0.001). Normalization of lactate <6 hours after ICU admission revealed better survival compared with normalization of lactate >6 hours (mortality 16.6% vs. 24.4%; p < 0.001). AUC of ROC curves to predict in-hospital mortality was the largest for max-lactate, whereas it was not different among all other lactate derived variables (all p > 0.05). The area under the ROC curves for admission lactate and lactate-time-integral was not different (p = 0.36). Conclusions Hyperlactatemia is associated with in-hospital mortality in a heterogeneous ICU population. In our patients, lactate peak values predicted in-hospital mortality equally well as lactate-time-integral of arterial blood lactate levels above the upper normal threshold. PMID:23446002

  19. Regulation of bone mineral loss during lactation

    NASA Technical Reports Server (NTRS)

    Brommage, R.; Deluca, H. F.

    1985-01-01

    The effects of varyng dietary calcium and phosphorous levels, vitamin D deficiency, oophorectomy, adrenalectomy, and simultaneous pregnancy on bone mineral loss during lactation in rats are studied. The experimental procedures and evaluations are described. The femur ash weight of lactating and nonlactating rats are calculated. The data reveals that a decrease in dietary calcium of 0.02 percent results in an increased loss of bone mineral, an increase in calcium to 1.4 percent does not lessen bone mineral loss, and bone mineral loss in vitamin D deficient rats is independent of calcium levels. It is observed that changes in dietary phosphorous level, oophorectomy, adrenalectomy, and simultaneous pragnancy do not reduce bone mineral loss during lactation. The analysis of various hormones to determine the mechanism that triggers bone mineral loss during lactation is presented.

  20. [Bone loss in lactating women and post-pregnancy osteoporosis].

    PubMed

    Hirata, Go; Chaki, Osamu

    2011-09-01

    Measurement of the bone mineral density have shown that lactating women had 1 to 3% decrease in bone mineral density. Post pregnancy osteoporosis is rare condition that causes fragile fracture mostly in vertebrae. The bone loss in lactating women is caused by calcium loss, decrease in estrogen level, and increase in PTHrP (parathyroid hormone related protein) level. Some data have shown that extended lactation and amenorrhea had an association with the degree of bone loss. Mostly, the bone loss of the lactating women recovers to the baseline level, soon after the weaning, and there is no long term effect. Post pregnancy osteoporosis should be concerned, when we see a lactating woman with fragile fracture of the vertebrae.

  1. Clinical value of jointly detection serum lactate dehydrogenase/pleural fluid adenosine deaminase and pleural fluid carcinoembryonic antigen in the identification of malignant pleural effusion.

    PubMed

    Zhang, Fan; Hu, Lijuan; Wang, Junjun; Chen, Jian; Chen, Jie; Wang, Yumin

    2017-09-01

    Limited data are available for the diagnostic value, and for the diagnostic sensitivity and specificity of joint detection of serum lactate dehydrogenase (sLDH)/pleural fluid adenosine deaminase (pADA) and pleural fluid carcinoembryonic antigen (pCEA) in malignant pleural effusion (MPE). We collected 987 pleural effusion specimens (of which 318 were malignant pleural effusion, 374 were tubercular pleural effusion, and 295 were parapneumonic effusion specimens) from the First Affiliated Hospital of Wenzhou Medical University from July 2012 to March 2016. The pADA, sLDH, pleural fluid LDH (pLDH), serum C-reactive protein (sCRP), pleural fluid protein, pCEA, white blood cell (WBC), and red blood cell (RBC) were analyzed, and the clinical data of each group were collected for statistical analysis. The level of sLDH/pADA, pCEA, and RBC from the MPE group was markedly higher than the tuberculosis pleural effusion (TB) group (Mann-Whitney U=28422.000, 9278.000, 30518, P=.000, .000, .000) and the parapneumonic pleural fluid group (Mann-Whitney U=5972.500, 7113.000, 36750.500, P=.000, .000, .000). The receiver operating characteristic curve ROC showed that the area under the ROC curve (AUC) (=0.924, 0.841) of pCEA and sLDH/pADA (cutoff=4.9, 10.6) were significantly higher than other markers for the diagnosis of MPE. Thus, joint detection of pCEA and sLDH/pADA suggested that the sensitivity, specificity, and AUC was 0.94, 81.70, and 94.32 at the cutoff 0.16 and diagnostic performance was higher than pCEA or sLDH/pADA. Joint detection of sLDH/pADA and pCEA can be used as a good indicator for the identification of benign and MPE with higher sensitivity and specificity than pCEA or sLDH/pADA. © 2016 Wiley Periodicals, Inc.

  2. From gene to structure: Lactobacillus bulgaricus D-lactate dehydrogenase from yogurt as an integrated curriculum model for undergraduate molecular biology and biochemistry laboratory courses.

    PubMed

    Lawton, Jeffrey A; Prescott, Noelle A; Lawton, Ping X

    2018-05-01

    We have developed an integrated, project-oriented curriculum for undergraduate molecular biology and biochemistry laboratory courses spanning two semesters that is organized around the ldhA gene from the yogurt-fermenting bacterium Lactobacillus bulgaricus, which encodes the enzyme d-lactate dehydrogenase. The molecular biology module, which consists of nine experiments carried out over eleven sessions, begins with the isolation of genomic DNA from L. bulgaricus in yogurt and guides students through the process of cloning the ldhA gene into a prokaryotic expression vector, followed by mRNA isolation and characterization of recombinant gene expression levels using RT-PCR. The biochemistry module, which consists of nine experiments carried out over eight sessions, begins with overexpression of the cloned ldhA gene and guides students through the process of affinity purification, biochemical characterization of the purified LdhA protein, and analysis of enzyme kinetics using various substrates and an inhibitor, concluding with a guided inquiry investigation of structure-function relationships in the three-dimensional structure of LdhA using molecular visualization software. Students conclude by writing a paper describing their work on the project, formatted as a manuscript to be submitted for publication in a scientific journal. Overall, this curriculum, with its emphasis on experiential learning, provides hands-on training with a variety of common laboratory techniques in molecular biology and biochemistry and builds experience with the process of scientific reasoning, along with reinforcement of essential transferrable skills such as critical thinking, information literacy, and written communication, all within the framework of an extended project having the look and feel of a research experience. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):270-278, 2018. © 2018 The International Union of Biochemistry and Molecular Biology.

  3. [Bone histomorphometry of lactating and no lactating hyperthyroid rats].

    PubMed

    Serakides, Rogéria; Ocarino, Natália de Melo; Magalhães, Fernanda do Carmo; Souza, Cíntia de Almeida; Leite, Eveline Dias; Freitas, Edmilson Santos de

    2008-06-01

    The objective of this study was to verify if hyperthyroidism potentiates the osteopenia lactational. 24 adult female rats were distributed in four groups: euthyroid no lactating (control), euthyroid lactating, hyperthyroid no lactating and hyperthyroid lactating. 20 days after gestation, all the animals were necropsied. The thoracic and lumbar vertebrae, the femur and tibia were decalcified and processed for histomorphometric analysis. The euthyroid lactating group presented intense osteopenia in the studied bones. In the hyperthyroid no lactating group, there was not any change in trabecular bone percentage in none of the analyzed bone. In the hyperthyroid lactating group, there was osteopenia in the tibia and femur, similar to the one in the euthyroid lactating group. But the trabecular bone percentage in all the vertebral bodies was significantly larger in comparison with the euthyroid lactating group. It was concluded that the hyperthyroidism does not potentiate the osteopenia lactational in female rats, but it minimizes the vertebral osteopenia once it stimulates the osteoblastic activity.

  4. The presence of vaginal Lactobacillus species does not contribute to a measureable difference in amniotic fluid lactate levels collected from the vaginal tract of laboring women.

    PubMed

    Hall, Beverley; Wong, Diana; Healy, Clare; Tracy, Mark B; Tracy, Sally K; Rawlinson, William D

    2017-04-01

    Amniotic fluid lactate research is based on the hypothesis that a relationship exists between fatigued uterine muscles and raised concentrations of the metabolite lactate, which is excreted into the amniotic fluid during labor. To assess potentially confounding effects of lactate-producing organisms on amniotic fluid lactate measurements, we aimed to determine if the presence of vaginal Lactobacillus species was associated with elevated levels of amniotic fluid lactate, measured from the vaginal tract of women in labor. Results from this study contribute to a large prospective longitudinal study of amniotic fluid lactate at a teaching hospital in Sydney, Australia. Amniotic fluid lactate measurement was assessed at the time of routine vaginal examination, after membranes had ruptured, using a hand-held lactate meter StatStripXPress (Nova Biomedical). Vaginal swab samples were collected at the time of the first amniotic fluid lactate measurement and stored for later detection and quantification of Lactobacillus species using a TaqMan real-time PCR assay. Swab sample and amniotic fluid lactate results were paired and analyzed. The PCR assay detected Lactobacillus species in 48 of 388 (12%) vaginal swab specimens (8% positive, 4% low positive) collected from women in labor after membranes had ruptured. There was no significant difference in median and mean (respectively) amniotic fluid lactate levels with (8.35 mmol/L; 8.95 mmol/L) or without (8.5 mmol/L; 9.08 mmol/L) Lactobacillus species detected. There was no association between the presence or level of vaginal Lactobacillus species and the measurement of amniotic fluid lactate collected from the vaginal tract of women during labor. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  5. The functional readthrough extension of malate dehydrogenase reveals a modification of the genetic code

    PubMed Central

    Hofhuis, Julia; Schueren, Fabian; Nötzel, Christopher; Lingner, Thomas; Gärtner, Jutta; Jahn, Olaf

    2016-01-01

    Translational readthrough gives rise to C-terminally extended proteins, thereby providing the cell with new protein isoforms. These may have different properties from the parental proteins if the extensions contain functional domains. While for most genes amino acid incorporation at the stop codon is far lower than 0.1%, about 4% of malate dehydrogenase (MDH1) is physiologically extended by translational readthrough and the actual ratio of MDH1x (extended protein) to ‘normal' MDH1 is dependent on the cell type. In human cells, arginine and tryptophan are co-encoded by the MDH1x UGA stop codon. Readthrough is controlled by the 7-nucleotide high-readthrough stop codon context without contribution of the subsequent 50 nucleotides encoding the extension. All vertebrate MDH1x is directed to peroxisomes via a hidden peroxisomal targeting signal (PTS) in the readthrough extension, which is more highly conserved than the extension of lactate dehydrogenase B. The hidden PTS of non-mammalian MDH1x evolved to be more efficient than the PTS of mammalian MDH1x. These results provide insight into the genetic and functional co-evolution of these dually localized dehydrogenases. PMID:27881739

  6. Comparative performance of aldolase and lactate dehydrogenase rapid diagnostic tests in Plasmodium vivax detection

    PubMed Central

    2014-01-01

    Background Misdiagnosis of malaria by commercial rapid diagnostic tests (RDTs) is a major cause of concern in the diagnosis of malaria. This retrospective study was aimed at assessing the relative performance of four RDTs with emphasis on the detection of two Plasmodium vivax antigens: aldolase and lactate dehydrogenase (LDH). Methods Three commercially available Plasmodium LDH or aldolase antigen detection kits (One Step Malaria P.f/P.v, ParaHit Total ver. 1.0, SD Bioline Malaria) and an anti-P. vivax aldolase-specific monoclonal antibody (mAb) pair 1C3-12 F10 were evaluated with P. vivax positive as well as non-P. vivax samples and healthy samples using blood smear examination as standard. Each test was read according to the manufacturer’s instructions. Results MAb 1C3-12 F10 pair targeting P. vivax-specific aldolase exhibited very good specificity and sensitivity of 100 and 97.4%, respectively. Positive predictive value (PPV) and negative predictive value (NPV) of 100 and 99.5%, respectively, were also observed. The anti-P. vivax LDH in the One-Step Malaria P.f/P.v test showed sensitivity, specificity, PPV and NPV of 93.5, 98.0, 88.9 and 98.8%, respectively. ParaHit Total ver. 1.0 targeting the pan-aldolase antigen showed sensitivity, specificity of 97.4 and 99.6%, respectively. PPV and NPV were both 99.5%. SD Bioline had sensitivity, specificity, PPV and NPV of 93.5, 100, 100 and 98.8%, respectively. The overall sensitivity and specificity of all four RDTs were acceptable, especially for the aldolase detection tests. Five (6.5%) of the P. vivax-positive samples (n = 77) that were confirmed by microscopic examination as well as the two aldolase detection RDTs (mAb 1C3-12 F10 and ParaHit Total ver.1.0) were undetected by the two LDH detection RDTs (One Step Malaria P.f/P.v and SD Bioline). Similarly, two positive samples (2.6%) that were positively confirmed by the LDH detection RDTs were also undetected by the aldolase detection test kits. Conclusion

  7. Decreases in activation energy and substrate affinity in cold-adapted A4-lactate dehydrogenase: evidence from the Antarctic notothenioid fish Chaenocephalus aceratus.

    PubMed

    Fields, Peter A; Houseman, Daniel E

    2004-12-01

    Enzyme function is strongly affected by temperature, and orthologs from species adapted to different thermal environments often show temperature compensation in kinetic properties. Antarctic notothenioid fishes live in a habitat of constant, extreme cold (-1.86 +/- 2 degrees C), and orthologs of the enzyme A4-lactate dehydrogenase (A4-LDH) in these species have adapted to this environment through higher catalytic rates, lower Arrhenius activation energies (Ea), and increases in the apparent Michaelis constant for the substrate pyruvate (Km(PYR)). Here, site-directed mutagenesis was used to determine which amino acid substitutions found in A4-LDH of the notothenioid Chaenocephalus aceratus, with respect to orthologs from warm-adapted teleosts, are responsible for these adaptive changes in enzyme function. Km(PYR) was measured in eight single and two double mutants, and Ea was tested in five single and two double mutants in the temperature range 0 degrees C-20 degrees C. Of the four mutants that had an effect on these parameters, two increased Ea but did not affect Km(PYR) (Gly224Ser, Ala310Pro), and two increased both Ea and Km(PYR) (Glu233Met, Gln317Val). The double mutants Glu233Met/Ala310Pro and Glu233Met/Gln317Val increased Km(PYR) and Ea to levels not significantly different from the A4-LDH of a warm temperate fish (Gillichthys mirabilis, habitat temperature 10 degrees C-35 degrees C). The four single mutants are associated with two alpha-helices that move during the catalytic cycle; those that affect Ea but not Km(PYR) are further from the active site than those that affect both parameters. These results provide evidence that (1) cold adaptation in A4-LDH involves changes in mobility of catalytically important molecular structures; (2) these changes may alter activation energy alone or activation energy and substrate affinity together; and (3) the extent to which these parameters are affected may depend on the location of the substitutions within the mobile

  8. Function of muscle-type lactate dehydrogenase and citrate synthase of the Galápagos marine iguana, Amblyrhynchus cristatus, in relation to temperature.

    PubMed

    Fields, Peter A; Strothers, Chad M; Mitchell, Mark A

    2008-05-01

    The Galápagos marine iguana, Amblyrhynchus cristatus, is unique among lizards in foraging subtidally, leading to activity across a broad range of ambient temperatures ( approximately 14-40 degrees C). To determine whether the marine iguana shows any biochemical changes consistent with maintaining enzyme function at both warm and cold body temperatures, we examined the function of the aerobic enzyme citrate synthase (CS) and the muscle isoform of the anaerobic enzyme lactate dehydrogenase (A(4)-LDH) in A. cristatus and a confamilial species, Iguana iguana, from 14 to 46 degrees C. We also deduced amino acid sequences from cDNA of each enzyme. In CS, despite two amino acid substitutions, we found no difference in the apparent Michaelis-Menten constant K(m) of oxaloacetate at any temperature, indicating that the substrate affinity of CS in A. cristatus has not adapted to changes in thermal environment. In A(4)-LDH, we used site-directed mutagenesis to show that the substitutions T9A and I283V (A. cristatus --> I. iguana) individually have no effect on kinetics, but together significantly decrease the K(m) of pyruvate and catalytic rate constant (k(cat)) of the A. cristatus ortholog. Thus, our data show that A. cristatus A(4)-LDH has not become cold adapted in response to this species' aquatic foraging behavior, and instead may be consistent with moderate warm adaptation with respect to the I. iguana ortholog.

  9. Blood lactate changes in professional Indian divers under hyperbaric conditions

    PubMed Central

    Sikri, Gaurav; Singh, S.P.; Srinivasa, A.B.; Chaudhry, H.B.S.

    2016-01-01

    Background Hyperoxia due to hyperbaric conditions influences lactate metabolism. Previous studies on lactate levels in hyperbaric conditions have reported varied results depending on the depth of evaluation and breathing gas mixture used. Methods This study compared post-exercise blood lactate levels of Indian professional male divers (breathing ambient air under normobaric conditions) with their post-exercise blood lactate levels measured under simulated hyperbaric conditions. Result In the present study, blood lactate levels in divers were found to have decreased significantly during recovery phase of exercise in hyperbaric conditions of dry diving at 2.8 Atmospheres Absolute (ATA) as compared to normobaric conditions. A significant improvement was observed in physical performance in terms of HR max and duration of exercise. Conclusion This study revealed that hyperoxia due to moderate hyperbaric condition leads to improvement in lactate metabolism in muscles and organs (liver and heart) for its removal. PMID:26900221

  10. A protocol for resuscitation of severe burn patients guided by transpulmonary thermodilution and lactate levels: a 3-year prospective cohort study.

    PubMed

    Sánchez, Manuel; García-de-Lorenzo, Abelardo; Herrero, Eva; Lopez, Teresa; Galvan, Beatriz; Asensio, María; Cachafeiro, Lucia; Casado, Cesar

    2013-08-15

    The use of urinary output and vital signs to guide initial burn resuscitation may lead to suboptimal resuscitation. Invasive hemodynamic monitoring may result in over-resuscitation. This study aimed to evaluate the results of a goal-directed burn resuscitation protocol that used standard measures of mean arterial pressure (MAP) and urine output, plus transpulmonary thermodilution (TPTD) and lactate levels to adjust fluid therapy to achieve a minimum level of preload to allow for sufficient vital organ perfusion. We conducted a three-year prospective cohort study of 132 consecutive critically burned patients. These patients underwent resuscitation guided by MAP (>65 mmHg), urinary output (0.5 to 1 ml/kg), TPTD and lactate levels. Fluid therapy was adjusted to achieve a cardiac index (CI) >2.5 L/minute/m² and an intrathoracic blood volume index (ITBVI) >600 ml/m2, and to optimize lactate levels. Statistical analysis was performed using mixed models. We also used Pearson or Spearman methods and the Mann-Whitney U-test. A total of 98 men and 34 women (mean age, 48 ± 18 years) was studied. The mean total body surface area (TBSA) burned was 35% ± 22%. During the early resuscitation phase, lactate levels were elevated (2.58 ± 2.05 mmol/L) and TPTD showed initial hypovolemia by the CI (2.68 ± 1.06 L/minute/m²) and the ITBVI (709 ± 254 mL/m²). At 24 to 32 hours, the CI and lactic levels were normalized, although the ITBVI remained below the normal range (744 ± 276 ml/m²). The mean fluid rate required to achieve protocol targets in the first 8 hours was 4.05 ml/kg/TBSA burned, which slightly increased in the next 16 hours. Patients with a urine output greater than or less than 0.5 ml/kg/hour did not show differences in heart rate, mean arterial pressure, CI, ITBVI or lactate levels. Initial hypovolemia may be detected by TPTD monitoring during the early resuscitation phase. This hypovolemia might not be reflected by blood pressure and hourly urine output. An

  11. The effect of trinitrobenzene sulfonic acid (TNB) on colonocyte arachidonic acid metabolism.

    PubMed

    Stratton, M D; Sexe, R; Peterson, B; Kaminski, D L; Li, A P; Longo, W E

    1996-02-01

    In previous studies we found that luminal perfusion of the isolated left colon of the rabbit with the hapten, trinitrobenzene, resulted in the production of an acute inflammatory process associated with alterations in eicosanoid metabolism. As the colitis was attenuated by cyclooxygenase inhibitors it is possible that the inflammation was mediated by arachidonic acid metabolites. In the present study it was intended to evaluate the effect of trinitrobenzene on eicosanoid metabolism in transformed human colonic cells by exposing Caco-2++ cells to various doses of trinitrobenzene. Cell injury was evaluated by measuring lactate dehydrogenase levels and cyclooxygenase and lipoxygenase activity was evaluated by measuring prostanoid and leukotriene production. In separate experiments resting and trinitrobenzene stimulated cells were treated with indomethacin and dexamethasone. Trinitrobenzene produced increased prostaglandin E2 and 6-keto prostaglandin F1alpha++ and increased lactate dehydrogenase levels. Leukotriene B4 was significantly increased compared to control values at the highest TNB concentration administered. Indomethacin inhibited the lactate dehydrogenase and prostanoid changes, suggesting that the inflammatory changes produced were mediated by the prostanoids. Dexamethasone administered for 1 hr prior to trinitrobenzene decreased the 6-keto prostaglandin F1alpha but did not alter trinitrobenzene produced changes in lactate dehydrogenase concentrations. Exposure of Caco-2 cells to dexamethasone for 24 hr decreased the trinitrobenzene produced lactate dehydrogenase and eicosanoid changes. The results suggest that trinitrobenzene produces an acute injury to Caco-2 cells that may be mediated by the cyclooxygenase enzymes.

  12. Alcohol consumption decreases lactate clearance in acutely injured patients☆

    PubMed Central

    Dezman, Zachary D.W.; Comer, Angela C.; Narayan, Mayur; Scalea, Thomas M.; Hirshon, Jon Mark; Smith, Gordon S.

    2017-01-01

    Introduction Alcohol, a common risk factor for injury, has direct toxic effects on the liver. The use of lactate clearance has been well described as an indicator of the adequacy of resuscitation in injured patients. We investigated whether acutely injured patients with positive blood alcohol content (+BAC) had less lactate clearance than sober patients. Methods We conducted a retrospective cohort study of acutely injured patients treated at an urban Level 1 trauma centre between January 2010 and December 2012. Blood alcohol and venous lactate levels were measured on all patients at the time of arrival. Study subjects were patients transported directly from the scene of injury, who had an elevated lactate concentration on arrival (≥3.0 mmol/L) and at least one subsequent lactate measurement within 24 h after admission. Lactate clearance ([Lactate1 − Lactate2]/Lactate1) was calculated for all patients. Chi-squared tests were used to compare values from sober and intoxicated subjects. Lactate clearance was plotted against alcohol levels and stratified by age and Injury Severity Score (ISS). Results Serial lactate concentration measurements were obtained in 3910 patients; 1674 of them had +BAC. Patients with +BAC were younger (mean age: 36.6 [SD 14.7] vs 41.0 [SD 19.9] years [p = 0.0001]), were more often male (83.4% vs 75.9% [p = 0.0001]), had more minor injuries (ISS < 9) (33.8% vs 27.1% [p = 0.0001]), had a lower in-hospital mortality rate (1.4% vs 3.9% [p = 0.0001]), but also had lower average lactate clearance (37.8% vs 47.6% [p = 0.0001]). The lactate clearance of the sober patients (47.6 [SD 33.5]) was twice that of those with +BAC >400 (23.5 [SD 6.5]). Lactate clearance decreased with increasing BAC irrespective of age and ISS. Conclusions In a large group of acutely injured patients, a dose-dependent decrease in lactate clearance was seen in those with elevated BAC. This relationship will cause a falsely elevated lactate reading or prolong lactate

  13. Roles of pyruvate dehydrogenase and branched-chain α-keto acid dehydrogenase in branched-chain membrane fatty acid levels and associated functions in Staphylococcus aureus.

    PubMed

    Singh, Vineet K; Sirobhushanam, Sirisha; Ring, Robert P; Singh, Saumya; Gatto, Craig; Wilkinson, Brian J

    2018-04-01

    Membrane fluidity to a large extent is governed by the presence of branched-chain fatty acids (BCFAs). Branched-chain α-keto acid dehydrogenase (BKD) is the key enzyme in BCFA synthesis. A Staphylococcus aureus BKD-deficient strain still produced substantial levels of BCFAs. Pyruvate dehydrogenase (PDH) with structural similarity to BKD has been speculated to contribute to BCFAs in S. aureus. This study was carried out using BKD-, PDH- and BKD : PDH-deficient derivatives of methicillin-resistant S. aureus strain JE2. Differences in growth kinetics were evaluated spectrophotometrically, membrane BCFAs using gas chromatography and membrane fluidity by fluorescence polarization. Carotenoid levels were estimated by measuring A465 of methanol extracts from 48 h cultures. MIC values were determined by broth microdilution.Results/Key findings. BCFAs made up 50 % of membrane fatty acids in wild-type but only 31 % in the BKD-deficient mutant. BCFA level was ~80 % in the PDH-deficient strain and 38 % in the BKD : PDH-deficient strain. BKD-deficient mutant showed decreased membrane fluidity, the PDH-deficient mutant showed increased membrane fluidity. The BKD- and PDH-deficient strains grew slower and the BKD : PDH-deficient strain grew slowest at 37 °C. However at 20 °C, the BKD- and BKD : PDH-deficient strains grew only a little followed by autolysis of these cells. The BKD-deficient strain produced higher levels of staphyloxanthin. The PDH-deficient and BKD : PDH-deficient strains produced very little staphyloxanthin. The BKD-deficient strain showed increased susceptibility to daptomycin. The BCFA composition of the cell membrane in S. aureus seems to significantly impact cell growth, membrane fluidity and resistance to daptomycin.

  14. DB Dehydrogenase: an online integrated structural database on enzyme dehydrogenase.

    PubMed

    Nandy, Suman Kumar; Bhuyan, Rajabrata; Seal, Alpana

    2012-01-01

    Dehydrogenase enzymes are almost inevitable for metabolic processes. Shortage or malfunctioning of dehydrogenases often leads to several acute diseases like cancers, retinal diseases, diabetes mellitus, Alzheimer, hepatitis B & C etc. With advancement in modern-day research, huge amount of sequential, structural and functional data are generated everyday and widens the gap between structural attributes and its functional understanding. DB Dehydrogenase is an effort to relate the functionalities of dehydrogenase with its structures. It is a completely web-based structural database, covering almost all dehydrogenases [~150 enzyme classes, ~1200 entries from ~160 organisms] whose structures are known. It is created by extracting and integrating various online resources to provide the true and reliable data and implemented by MySQL relational database through user friendly web interfaces using CGI Perl. Flexible search options are there for data extraction and exploration. To summarize, sequence, structure, function of all dehydrogenases in one place along with the necessary option of cross-referencing; this database will be utile for researchers to carry out further work in this field. The database is available for free at http://www.bifku.in/DBD/

  15. Effect of various kinds of beverages on stress oxidative, F2 isoprostane, serum lipid and blood glucose of elite taekwondo players.

    PubMed

    Maghsoudi, Zahra; Shiranian, Ashfin; Askai, Gholamreza; Ghaisvand, Reza

    2016-01-01

    Athletes' recovery is important in improving their performance. Nutritional strategies can be effective in enhancing recovery rate. Choosing the best food items in appropriate intervals can play effective roles in resynthesis of fuels and recovery of muscle injury. Beverage micro and macronutrient content are helpful in fuel restoration. In this study, we assess the effects of various kinds of beverages on oxidative stress, muscle injury, and metabolic risk factors in taekwondo players. This quasi-experimental study was performed on 21 taekwondo players of Isfahan. After collecting fasting blood, they performed runningbased anaerobic sprint test (RAST). Blood lactate was tested again and participants were divided into 3 intervention groups, that is, receiving 500 cc dough, non-alcoholic beer, and chocolate milk at 4 day intervals. After a 2-h recovery period, blood sampling was repeated. Elites consumed other beverages in later phases. Dietary intake and fasting triglyceride, cholesterol, blood sugar, lactate dehydrogenase, and F 2 -isoprostane concentrations were determined. Data were analyzed with a simple repeated-measures test and post-hoc tests using the Statistical Package for the Social Sciences software. Data showed that cholesterol levels non-significantly decreased after intervention. Triglyceride level was lower after taking dough and carbohydrate replacement drink. Blood glucose concentration increased after intervention periods, however, this increase was significant only after non-alcoholic beverage consumption. Lactate dehydrogenase levels reduced after all cycles, however, F 2 -isoprostane level showed no significant change. There was not significant change in lactate dehydrogenase and F 2 -isoprostane levels. Non-alcoholic beer consumption can reduce lactate dehydrogenase concentration; however, it leads to blood sugar increase. Moreover, dough consumption significantly reduced triglyceride level in taekwondo players.

  16. Functional and structural characterization of the pentapeptide insertion of Theileria annulata lactate dehydrogenase by site-directed mutagenesis, comparative modeling and molecular dynamics simulations.

    PubMed

    Erdemir, Aysegul; Mutlu, Ozal

    2017-06-01

    Lactate dehydrogenase (LDH) is an important metabolic enzyme in glycolysis and it has been considered as the main energy source in many organisms including apicomplexan parasites. Differences at the active site loop of the host and parasite LDH's makes this enzyme an attractive target for drug inhibitors. In this study, five amino acid insertions in the active site pocket of Theileria annulata LDH (TaLDH) were deleted by PCR-based site-directed mutagenesis, expression and activity analysis of mutant and wild type TaLDH enzymes were performed. Removal of the insertion at the active site loop caused production of an inactive enzyme. Furthermore, structures of wild and mutant enzymes were predicted by comparative modeling and the importance of the insertions at the active site loop were also assigned by molecular docking and dynamics simulations in order to evaluate essential role of this loop for the enzymatic activity. Pentapeptide insertion removal resulted in loss of LDH activity due to deletion of Trp96 and conformational change of Arg98 because of loop instability. Analysis of wild type and mutant enzymes with comparative molecular dynamics simulations showed that the fluctuations of the loop residues increase in mutant enzyme. Together with in silico studies, in vitro results revealed that active site loop has a vital role in the enzyme activity and our findings promise hope for the further drug design studies against theileriosis and other apicomplexan parasite diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Economic weights for genetic improvement of lactation persistency and milk yield.

    PubMed

    Togashi, K; Lin, C Y

    2009-06-01

    This study aimed to establish a criterion for measuring the relative weight of lactation persistency (the ratio of yield at 280 d in milk to peak yield) in restricted selection index for the improvement of net merit comprising 3-parity total yield and total lactation persistency. The restricted selection index was compared with selection based on first-lactation total milk yield (I(1)), the first-two-lactation total yield (I(2)), and first-three-lactation total yield (I(3)). Results show that genetic response in net merit due to selection on restricted selection index could be greater than, equal to, or less than that due to the unrestricted index depending upon the relative weight of lactation persistency and the restriction level imposed. When the relative weight of total lactation persistency is equal to the criterion, the restricted selection index is equal to the selection method compared (I(1), I(2), or I(3)). The restricted selection index yielded a greater response when the relative weight of total lactation persistency was above the criterion, but a lower response when it was below the criterion. The criterion varied depending upon the restriction level (c) imposed and the selection criteria compared. A curvilinear relationship (concave curve) exists between the criterion and the restricted level. The criterion increases as the restriction level deviates in either direction from 1.5. Without prior information of the economic weight of lactation persistency, the imposition of the restriction level of 1.5 on lactation persistency would maximize change in net merit. The procedure presented allows for simultaneous modification of multi-parity lactation curves.

  18. Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials.

    PubMed

    Bastiaens, Guido J H; Tiono, Alfred B; Okebe, Joseph; Pett, Helmi E; Coulibaly, Sam A; Gonçalves, Bronner P; Affara, Muna; Ouédraogo, Alphonse; Bougouma, Edith C; Sanou, Guillaume S; Nébié, Issa; Bradley, John; Lanke, Kjerstin H W; Niemi, Mikko; Sirima, Sodiomon B; d'Alessandro, Umberto; Bousema, Teun; Drakeley, Chris

    2018-01-01

    Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the study participants developed moderate or

  19. Lactate Profile During Greco-Roman Wrestling Matchx

    PubMed Central

    Karnincic, Hrvoje; Tocilj, Zoran; Uljevic, Ognjen; Erceg, Marko

    2009-01-01

    The objective of this study was to determine and compare lactate profile of two groups of Greco-Roman wrestlers with different competences and training experience. Study was conducted on 10 wrestles that were members of Croatian national team and 10 wrestlers that were members of Wrestling club Split. Lactate samples were collected at four intervals during control fights that were held according to international wrestling rules of World wrestling federation FILA. Values of lactate increased as competition progressed, and they were highest at the end of the match for both groups of wrestlers. According to this study there were no significant differences in lactate between two groups at the end of the match, while significant differences were noted during the match. The information about lactate profile presented in this study can be used by coaches and wrestlers to develop condition programs. Key Points There were no significant differences in lactate concentrations at the end of the match between two proficiency levels of wrestlers. More proficient (elite) wrestlers raise lactates gradually through the wrestling match while less proficient (club) wrestlers raise it abruptly at the end of the first bout. Both groups of wrestlers are unable to sustain same level of activity through the match suggesting that they are utilizing too much energy from anaerobic glycolysis. PMID:24474881

  20. Zinc, lead, and cadmium levels in serum and milk of lactating women in Ibadan, Nigeria.

    PubMed

    Edem, Victory Fabian; Akintunde, Kikelomo; Adelaja, Yewande Adeola; Nwozo, Sarah O; Charles-Davies, Mabel

    2017-01-01

    Zinc (Zn) is known to interact with lead (Pb) and cadmium (Cd) reversing their toxicity and reducing their concentrations. However, lactating women are at high risk of developing Zn deficiency, which may result in Pb and Cd intoxication or increased exposure of breast-fed infants to Pb and Cd from breast milk. The aim of this study was to determine Zn, Pb, and Cd concentrations and examine their relationship in serum and breast milk of lactating women in Ibadan, Nigeria. Ninety-two lactating women were recruited into this study. Anthropometric measurements were assessed by standard methods while serum and breast milk concentrations of Zn, Pb, and Cd were assessed by atomic absorption spectrophotometry. Data analyzed statistically by Student's t test, Pearson's correlation coefficient, and a multiple regression model were significant at p < 0.05. Zn deficiency was observed in 12 (17.1%) of lactating women. Breast milk levels of Zn, Pb, and Cd were significantly higher than their levels in serum, whereas the ratios Zn:Pb and Zn:Cd in milk were significantly less than serum ratios. Significant negative correlation was observed between milk Pb and serum Zn:Pb while milk Cd correlated positively with milk Zn. Significant positive correlations were observed between serum Zn and serum Zn:Pb, serum Zn and serum Zn:Cd, as well as serum Zn:Cd and serum Zn:Pb. Serum Cd and serum Zn were significantly negatively related. Significant negative correlations between serum Pb and serum Zn:Pb as well as milk Zn:Pb. Serum Cd and serum Zn:Pb as well as serum Zn:Cd correlated negatively. Milk Cd and Zn/Cd positively related with milk Pb while milk Zn was a negatively related with milk Pb in a multiple regression model ( R 2 = 0.333; p = 0.023). Breast milk may be contaminated by toxic metals. However, Zn supplementation in deficient mothers may protect maternal and infant health.

  1. Effects of Hypergravity Exposure on Prolactin Levels in Pre-parturient , Parturient and Lactating Rat Dams

    NASA Technical Reports Server (NTRS)

    Baer. Lisa A.; Wade, Charles E.; Ronca, April E.; Sun, Sid (Technical Monitor)

    2001-01-01

    We analyzed the effects of 2.0-g, 1.75-g and 1.5-g hypergravity exposure on plasma concentrations of the lactotrophic hormone, prolactin (PRL), in female rats on pre-parturient (Gestation Day 20), parturient (Post-natal day 0) and lactating (P10) days. PRL levels have been found to be reduced in rat dams around the time of birth following exposure to gravitational loads varying from 2.16 to 3.14-g (Megory et. al., Aviation, Space and Environs 1129-1135, 1984). It has also been reported that at these high gravitational loads, neonatal mortality has been extremely high, suggesting a possible interaction between dam PRL concentration and neonatal outcome. We have previously reported no significant differences in PRL levels of parturient (PO) and lactating (P6 & P 15) dams when exposed to 1.5-g hypergravity, but did observe a slight elevation of PRL on PO and P 15, with a decrease on P6. In the present study, time-bred pregnant dams were exposed to either continuous 2.0-g, 1.75-g or 1.5-g centrifugation, beginning on Gestational day (G) 11 of the rats' 22-day pregnancy. We observed no significant differences in PRL concentrations between SC and any of the HG conditions. On G20 and PO, PRL concentrations of the 2.0-g and 1.5-g groups were slightly elevated as compared to SC. Similar to what we previously reported. PRL secretion was elevated in both HG and SC conditions on the day of birth relative to later during lactation, but on P10 it appeared to be reduced in HG relative to SC dams. These findings suggests that hypergravity slightly elevates plasma concentration of PRL in pre-parturient and lactating rat dams, with effects most pronounced during the periparturitional period and in a direction opposite to that observed following microgravity exposure.

  2. The BRAF inhibitor vemurafenib activates mitochondrial metabolism and inhibits hyperpolarized pyruvate-lactate exchange in BRAF mutant human melanoma cells

    PubMed Central

    Delgado-Goni, Teresa; Falck Miniotis, Maria; Wantuch, Slawomir; Parkes, Harold G.; Marais, Richard; Workman, Paul; Leach, Martin O.; Beloueche-Babari, Mounia

    2016-01-01

    Understanding the impact of BRAF signaling inhibition in human melanoma on key disease mechanisms is important for developing biomarkers of therapeutic response and combination strategies to improve long term disease control. This work investigates the downstream metabolic consequences of BRAF inhibition with vemurafenib, the molecular and biochemical processes that underpin them, their significance for antineoplastic activity and potential as non-invasive imaging response biomarkers.1H NMR spectroscopy showed that vemurafenib decreases the glycolytic activity of BRAF mutant (WM266.4 and SKMEL28) but not BRAFWT (CHL-1 and D04) human melanoma cells. In WM266.4 cells, this was associated with increased acetate, glycine and myo-inositol levels and decreased fatty acyl signals, while the bioenergetic status was maintained. 13C NMR metabolic flux analysis of treated WM266.4 cells revealed inhibition of de novo lactate synthesis and glucose utilization, associated with increased oxidative and anaplerotic pyruvate carboxylase mitochondrial metabolism and decreased lipid synthesis. This metabolic shift was associated with depletion of HKII, acyl-CoA dehydrogenase 9, 3-phosphoglycerate dehydrogenase and monocarboxylate transporter (MCT) 1 and 4 in BRAF mutant but not BRAFWT cells and, interestingly, decreased BRAF mutant cell dependency on glucose and glutamine for growth. Further, the reduction in MCT1 expression observed led to inhibition of hyperpolarized 13C-pyruvate-lactate exchange, a parameter that is translatable to in vivo imaging studies, in live WM266.4 cells. In conclusion, our data provide new insights into the molecular and metabolic consequences of BRAF inhibition in BRAF-driven human melanoma cells that may have potential for combinatorial therapeutic targeting as well as non-invasive imaging of response. PMID:27765851

  3. Evaluation of urinary S100B protein level and lactate/creatinine ratio for early diagnosis and prognostic prediction of neonatal hypoxic-ischemic encephalopathy.

    PubMed

    Liu, Li; Zheng, Chong-Xun; Peng, Shu-Feng; Zhou, Hong-Yan; Su, Zu-You; He, Li; Ai, Ting

    2010-01-01

    Early identification and prevention of hypoxic-ischemic encephalopathy (HIE) in newborns may reduce neonatal mortality and neurological dysfunction. To analyze the diagnostic and prognostic values of urinary S100B level and lactate/creatinine ratio in newborns with HIE. Seventy-eight full-term newborns with HIE and 25 normal newborns were enrolled. The Neonatal Behavioral Neurological Assessment (NBNA) and Developmental Screening Test were scored. The concentration of urinary S100B protein was determined using the S100B enzyme-linked immunosorbent assay and the levels of urinary lactate and creatinine were measured with the enzyme colorimetric method. Urinary S100B level on days 1-3 after birth and lactate/creatinine ratio on day 1 were significantly higher in newborns with HIE than those in the control group. Both indexes were positively correlated with the clinical grading of HIE. A cutoff value for the S100B level of 0.47 microg/l on day 3 after birth had a sensitivity of 90% and specificity of 92% for prediction of HIE. A lactate/creatinine ratio of more than 0.55 on day 1 showed the highest sensitivity (92%) and specificity (90%). A combination of both indexes improved the sensitivity and specificity to 99 and 97%, respectively. A negative correlation of both lactate/creatinine ratio on day 1 and S100B level on days 1-3 after birth with the NBNA score was identified on days 3, 7 and 14 after birth. The Developmental Screening Test score of 36 newborns with HIE within 6 months after birth showed that 65% of infants with moderate and high HIE had an abnormal developmental quotient. These data suggest that early measurement of both S100B level and lactate/creatinine ratio in the urine of newborns with HIE is a practical convenient and sensitive way to improve diagnosis on the third day of life and prognostic prediction of HIE. Copyright 2009 S. Karger AG, Basel.

  4. Bioactivity-Guided Identification and Cell Signaling Technology to Delineate the Lactate Dehydrogenase A Inhibition Effects of Spatholobus suberectus on Breast Cancer

    PubMed Central

    Wang, Zhiyu; Wang, Dongmei; Han, Shouwei; Wang, Neng; Mo, Feizhi; Loo, Tjing Yung; Shen, Jiangang; Huang, Hui; Chen, Jianping

    2013-01-01

    Aerobic glycolysis is an important feature of cancer cells. In recent years, lactate dehydrogenase A (LDH-A) is emerging as a novel therapeutic target for cancer treatment. Seeking LDH-A inhibitors from natural resources has been paid much attention for drug discovery. Spatholobus suberectus (SS) is a common herbal medicine used in China for treating blood-stasis related diseases such as cancer. This study aims to explore the potential medicinal application of SS for LDH-A inhibition on breast cancer and to determine its bioactive compounds. We found that SS manifested apoptosis-inducing, cell cycle arresting and anti-LDH-A activities in both estrogen-dependent human MCF-7 cells and estrogen-independent MDA-MB-231 cell. Oral herbal extracts (1 g/kg/d) administration attenuated tumor growth and LDH-A expression in both breast cancer xenografts. Bioactivity-guided fractionation finally identified epigallocatechin as a key compound in SS inhibiting LDH-A activity. Further studies revealed that LDH-A plays a critical role in mediating the apoptosis-induction effects of epigallocatechin. The inhibited LDH-A activities by epigallocatechin is attributed to disassociation of Hsp90 from HIF-1α and subsequent accelerated HIF-1α proteasome degradation. In vivo study also demonstrated that epigallocatechin could significantly inhibit breast cancer growth, HIF-1α/LDH-A expression and trigger apoptosis without bringing toxic effects. The preclinical study thus suggests that the potential medicinal application of SS for inhibiting cancer LDH-A activity and the possibility to consider epigallocatechin as a lead compound to develop LDH-A inhibitors. Future studies of SS for chemoprevention or chemosensitization against breast cancer are thus warranted. PMID:23457597

  5. Lactate clearance as the predictor of outcome in pediatric septic shock.

    PubMed

    Choudhary, Richa; Sitaraman, Sadasivan; Choudhary, Anita

    2017-01-01

    Septic shock can rapidly evolve into multiple system organ failure and death. In the recent years, hyperlactatemia has been found to be a risk factor for mortality in critically ill adults. To evaluate the predictive value of lactate clearance and to determine the optimal cut-off value for predicting outcome in children with septic shock. A prospective observational study was performed on children with septic shock admitted to pediatric Intensive Care Unit (PICU). Serial lactate levels were measured at PICU admission, 24 and 48 h later. Lactate clearance, percent decrease in lactate level in 24 h, was calculated. The primary outcome measure was survival or nonsurvival at the end of hospital stay. We performed receiver operating characteristic analyses to calculate optimal cut-off values. The mean lactate levels at admission were significantly higher in the nonsurvivors than survivors, 5.12 ± 3.51 versus 3.13 ± 1.71 mmol/L ( P = 0.0001). The cut-off for lactate level at admission for the best prediction of mortality was determined as ≥4 mmol/L (odds ratio 5.4; 95% confidence interval [CI] =2.45-12.09). Mean lactate clearance was significantly higher in survivors than nonsurvivors (17.9 ± 39.9 vs. -23.2 ± 62.7; P < 0.0001). A lactate clearance rate of <10% at 24 h had a sensitivity and specificity of 78.7% and 72.2%, respectively and a positive predictive value of 83.1% for death. Failure to achieve a lactate clearance of more than 10% was associated with greater risk of mortality (likelihood ratio + 2.83; 95% CI = 1.82-4.41). Serial lactate levels can be used to predict outcome in pediatric septic shock. A 24 h lactate clearance cut-off of <10% is a predictor of in-hospital mortality in such patients.

  6. Metabolic engineering of mannitol production in Lactococcus lactis: influence of overexpression of mannitol 1-phosphate dehydrogenase in different genetic backgrounds.

    PubMed

    Wisselink, H Wouter; Mars, Astrid E; van der Meer, Pieter; Eggink, Gerrit; Hugenholtz, Jeroen

    2004-07-01

    To obtain a mannitol-producing Lactococcus lactis strain, the mannitol 1-phosphate dehydrogenase gene (mtlD) from Lactobacillus plantarum was overexpressed in a wild-type strain, a lactate dehydrogenase(LDH)-deficient strain, and a strain with reduced phosphofructokinase activity. High-performance liquid chromatography and (13)C nuclear magnetic resonance analysis revealed that small amounts (<1%) of mannitol were formed by growing cells of mtlD-overexpressing LDH-deficient and phosphofructokinase-reduced strains, whereas resting cells of the LDH-deficient transformant converted 25% of glucose into mannitol. Moreover, the formed mannitol was not reutilized upon glucose depletion. Of the metabolic-engineering strategies investigated in this work, mtlD-overexpressing LDH-deficient L. lactis seemed to be the most promising strain for mannitol production.

  7. A novel amperometric biosensor based on gold nanoparticles anchored on reduced graphene oxide for sensitive detection of l-lactate tumor biomarker.

    PubMed

    Azzouzi, Sawsen; Rotariu, Lucian; Benito, Ana M; Maser, Wolfgang K; Ben Ali, Mounir; Bala, Camelia

    2015-07-15

    In this work, a novel amperometric biosensor based on gold nanoparticles anchored on reduced graphene oxide (RGO-AuNPs) and l-lactate dehydrogenase (LDH) was developed for the sensing of l-lactate. Firstly, the RGO-AuNPs modified screen printed electrodes were tested for NADH detection showing a wide dynamic range and a low detection limit. Next, the biosensor was constructed by incorporating both enzyme and RGO-AuNPs in a sol gel matrix derived from tetrametoxysilane and methyltrimetoxysilane. The enzyme loading, working pH, and coenzyme concentration were optimized. The biosensor linearly responded to l-lactate in the range of 10µM-5mM and showed a good specific sensitivity of 154µA/mMcm(2) with a detection limit of 0.13µM. This was accompanied by good reproducibility and operational stability. Tests on artificial serum proved that l-lactate can be determined practically without interferences from commonly interfering compounds such as urate, paracetamol and l-ascorbate. Our LDH/RGO-AuNPs/SPCE based biosensor thus performs as electrochemical device for the detection of l-lactate as a viable early cancer bio-marker. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Supplementation of selenium, vitamin E, chromium and betaine above recommended levels improves lactating performance of sows over summer.

    PubMed

    Liu, Fan; Cottrell, Jeremy James; Collins, Cherie Louise; Henman, David James; O'Halloran, Kirrily Sharon Beatrice; Dunshea, Frank Rowland

    2017-10-01

    Heat stress (HS) exacerbates the body weight loss of lactating sows and reduces litter weight gain. Selenium (Se), vitamin E (VE), chromium (Cr) and betaine have been shown to ameliorate symptoms of HS, and yeast nucleotides and mannan oligosaccharides have been reported to improve lactational performance and immune response in pigs. Therefore, a combination of these nutrients may improve lactational performance of sows in summer. The effects of two nutritionally enhanced diets on lactational performance of sows in summer were investigated in two experiments. In experiment 1, we compared the effects of a nutritionally fortified diet (0.4 ppm Se, 95 IU/kg VE, 0.4 ppm Cr and 0.2% betaine; named as SVCB diet) with the NRC 2012 standard diet (0.15 ppm Se, 44 IU/kg VE) on lactational performance of sows in summer. Results showed that the SVCB diet reduced body weight loss (P = 0.039) and tended to reduce backfat loss (P = 0.075) of sows without affecting feed intake, while litter weight gain was not influenced. In experiment 2, we further enhanced the nutrients in the SVCB diet (0.8 ppm Se, 1% yeast nucleotides, and 0.1% mannan oligosaccharides; named as SNM diet). Results showed that the SNM diet did not improve feed intake of sows, farrowing performance, or litter weight gain compared with the SVCB diet, but increased body weight loss of the third parity sows (P = 0.037). Overall, a combined supplementation of Se, VE, Cr, and betaine above the NRC recommended levels can reduce mobilisation of body reserve of lactating sows in summer.

  9. Investigation of drying stresses on proteins during lyophilization: differentiation between primary and secondary-drying stresses on lactate dehydrogenase using a humidity controlled mini freeze-dryer.

    PubMed

    Luthra, Sumit; Obert, Jean-Philippe; Kalonia, Devendra S; Pikal, Michael J

    2007-01-01

    This article describes the design, performance testing, and application of a controlled humidity mini-freeze-dryer in studying the physical stability of lactate dehydrogenase during lyophilization. Performance evaluation of the mini-freeze-dryer was conducted with tests, namely water sublimation, radiation heat exchange, lowest achievable temperature, and leak testing. Protein stability studies were conducted by comparing protein activity at various stages of lyophilization with the initial activity. The shelf and condenser temperature were stable at <-40 degrees C, wall temperature was within 2 degrees C of the shelf temperature, and the leak rate was small. The chamber pressure was controlled by the ice on the condenser and the product temperature during sublimation was equal to the shelf temperature. Addition of Tween 80 prevented activity loss in solution and after freeze-thaw. No activity loss was observed after primary-drying even in absence of lyoprotectants and with collapse of cake structure. Five percent (w/w) sucrose concentration was required to achieve full stabilization. In conclusion, performance testing established that the mini-freeze-dryer was suitable for mechanistic freeze-drying studies. Secondary-drying was the critical step for protein stability. The concentration of sucrose required to stabilize the protein completely was several orders of magnitude higher than that required to satisfy the direct interaction requirement of the protein. (c) 2006 Wiley-Liss, Inc. and the American Pharmacists Association.

  10. Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus.

    PubMed

    Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

    2017-01-01

    Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic

  11. Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus*

    PubMed Central

    Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

    2017-01-01

    Background Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further

  12. Dichloroacetate effects on glucose and lactate oxidation by neurons and astroglia in vitro and on glucose utilization by brain in vivo.

    PubMed

    Itoh, Yoshiaki; Esaki, Takanori; Shimoji, Kazuaki; Cook, Michelle; Law, Mona J; Kaufman, Elaine; Sokoloff, Louis

    2003-04-15

    Neuronal cultures in vitro readily oxidized both D-[(14)C]glucose and l-[(14)C]lactate to (14)CO(2), whereas astroglial cultures oxidized both substrates sparingly and metabolized glucose predominantly to lactate and released it into the medium. [(14)C]Glucose oxidation to (14)CO(2) varied inversely with unlabeled lactate concentration in the medium, particularly in neurons, and increased progressively with decreasing lactate concentration. Adding unlabeled glucose to the medium inhibited [(14)C]lactate oxidation to (14)CO(2) only in astroglia but not in neurons, indicating a kinetic preference in neurons for oxidation of extracellular lactate over intracellular pyruvatelactate produced by glycolysis. Protein kinase-catalyzed phosphorylation inactivates pyruvate dehydrogenase (PDH), which regulates pyruvate entry into the tricarboxylic acid cycle. Dichloroacetate inhibits this kinase, thus enhancing PDH activity. In vitro dichloroacetate stimulated glucose and lactate oxidation to CO(2) and reduced lactate release mainly in astroglia, indicating that limitations in glucose and lactate oxidation by astroglia may be due to a greater balance of PDH toward the inactive form. To assess the significance of astroglial export of lactate to neurons in vivo, we attempted to diminish this traffic in rats by administering dichloroacetate (50 mgkg) intravenously to stimulate astroglial lactate oxidation and then examined the effects on baseline and functionally activated local cerebral glucose utilization (lCMR(glc)). Dichloroacetate raised baseline lCMR(glc) throughout the brain and decreased the percent increases in lCMR(glc) evoked by functional activation. These studies provide evidence in support of the compartmentalization of glucose metabolism between astroglia and neurons but indicate that the compartmentalization may be neither complete nor entirely obligatory.

  13. Capacitive malaria aptasensor using Plasmodium falciparum glutamate dehydrogenase as target antigen in undiluted human serum.

    PubMed

    Singh, Naveen K; Arya, Sunil K; Estrela, Pedro; Goswami, Pranab

    2018-06-08

    A capacitive aptasensor for detecting the malaria biomarker, Plasmodium falciparum glutamate dehydrogenase (PfGDH), directly in human serum samples developed. A thiolated ssDNA aptamer (NG3) that binds specifically to PfGDH antigen with high affinity (K d = 79 nM) was used to develop the aptasensor. The aptasensor produced capacitance response at an optimized frequency of 2 Hz in a non-Faradaic electrochemical impedance based signal transduction platform. The aptasensor exhibited a wide dynamic range of 100 fM-100 nM with a limits of detection of 0.77 pM in serum samples. The interference from other predominant malarial biomarkers, namely, Plasmodium falciparum -lactate dehydrogenase and -histidine rich protein-II on the aptasensor was negligible. This PfGDH aptasensor with highly sensitive and label free detection capability has great application potential for diagnosis of asymptotic malaria and monitoring the regression of malaria during treatment regime with antimalarial drugs. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Regional analyses of CNS microdialysate glucose and lactate in seizure patients.

    PubMed

    Cornford, Eain M; Shamsa, Kamran; Zeitzer, Jamie M; Enriquez, Cathleen M; Wilson, Charles L; Behnke, Eric J; Fried, Itzhak; Engel, Jerome

    2002-11-01

    To correlate glucose (and lactate) results obtained from microdialysate to recent studies suggesting that glucose transporter activity may be significantly altered in seizures. We used a fluorometric technique to quantify glucose and lactate levels in microdialysates collected from two to four depth electrodes implanted per patient in the temporal and frontal lobes of a series of four patients. Hour-by-hour and day-to-day changes in brain glucose and lactate levels at the same site were recorded. Additionally we compared regional variations in lactate/glucose ratios around the predicted epileptogenic region. Lactate/glucose ratios in the range of 1-2:1 were the most commonly seen. When the lactate/glucose ratio was <1:1, we typically observed a relative increase in local glucose concentration (rather than decreased lactate), suggesting increased transport, perhaps without increased glycolysis. In some sites, lactate/glucose ratios of 3:1-15:1 were seen, suggesting that a circumscribed zone of inhibition of tricarboxylic acid cycle activity may have been locally induced. In these dialysates, collected from probes closer to the epileptogenic region, the large increase in lactate/glucose ratios was a result of both increased lactate and reduced glucose levels. We conclude that regional variations in brain extracellular glucose concentrations may be of greater magnitude than previously believed and become even more accentuated in partial seizure patients. Data from concomitant assays of microdialysate lactate and glucose may aid in understanding cerebral metabolism.

  15. Effects of Stage of Lactation and Dietary Forage Level on Body Composition of Alpine Dairy Goats

    USDA-ARS?s Scientific Manuscript database

    Multiparous Alpine does (42) were used to determine how stage of lactation and dietary forage level affect body composition. Initial measures were made with six does a few days after kidding (0 mo). Before parturition does were fed a 50% concentrate diet free-choice. Eighteen does were fed a 40% ...

  16. Are arterial, muscle and working limb lactate exchange data obtained on men at altitude consistent with the hypothesis of an intracellular lactate shuttle?

    PubMed

    Brooks, G A

    1999-01-01

    The "Lactate Shuttle" Hypothesis posits that lactate removal requires exchange among producing and consuming cells. The "Intra-cellular Lactate Shuttle" hypothesis posits that lactate exchange occurs among compartments within cells, and that mitochondria are the major sites of cellular lactate disposal. Thus, cells with high mitochondrial densities (cardiocytes, myocytes, hepatocytes) are those which participate in lactate clearance. The model of an Intracellular Lactate Shuttle recognizes that the Keq for LDH is 3.6 x 10(4) M-1; thus, glycolysis results in cytosolic lactate production regardless of the intracellular PO2. The model also requires presence of a mitochondrial monocarboxylate transporter (MCT) that allows uptake of lactate as well as pyruvate, and intra-mitochondrial LDH whose function is linked to the ETC, and which permits lactate-->pyruvate conversion and oxidation. Recently, we have shown that liver, heart and muscle mitochondria readily oxidize lactate and contain LDH and MCT1. Accordingly, we have concluded that lactate is the predominant monocarboxylate oxidized by mitochondria in vivo. The model of an "Intra-cellular Lactate Shuttle" is consistent with many of the observations on men at sea level and altitude. The observations include: oxidation is the primary fate of lactate disposal during rest and exercise; lactate production and oxidation occur simultaneously within resting and working muscle; increasing [lactate]a increases muscle lactate extraction, and that by increasing SaO2 acclimatization reduces blood [lactate].

  17. 21 CFR 184.1768 - Sodium lactate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1768 Sodium lactate. (a) Sodium lactate (C3H5O3Na, CAS Reg. No. 72-17-3) is the sodium salt of lactic acid. It is prepared commercially by the neutralization of lactic acid with sodium hydroxide. (b) The... ingredient is used in food at levels not to exceed current good manufacturing practice. (d) Prior sanctions...

  18. An exploratory analysis of alkaline phosphatase, lactate dehydrogenase, and prostate-specific antigen dynamics in the phase 3 ALSYMPCA trial with radium-223

    PubMed Central

    Sartor, O.; Coleman, R. E.; Nilsson, S.; Heinrich, D.; Helle, S. I.; O’Sullivan, J. M.; Vogelzang, N. J.; Bruland, Ø.; Kobina, S.; Wilhelm, S.; Xu, L.; Shan, M.; Kattan, M. W.; Parker, C.

    2017-01-01

    Background Baseline clinical variables are prognostic for overall survival (OS) in patients with castration-resistant prostate cancer (CRPC). Their prognostic and predictive value with agents targeting bone metastases, such as radium-223, is not established. Patients and methods The radium-223 ALSYMPCA trial enrolled patients with CRPC and symptomatic bone metastases. Prognostic potential of baseline variables was assessed using Cox models. Percentage changes in biomarker levels from baseline were evaluated during the trial period; changes from baseline to week 12 were evaluated for association with OS and surrogacy. Results Eastern Cooperative Oncology Group performance status, total alkaline phosphatase (tALP), lactate dehydrogenase (LDH), and prostate-specific antigen (PSA) at baseline were associated with OS (P ≤ 0.0003) in the intent-to-treat population (radium-223, N = 614; placebo, N = 307). tALP declined from baseline within 4 weeks after beginning radium-223, by week 12 declining in 87% of radium-223 and 23% of placebo patients (P < 0.001). LDH declined in 51% and 34% (P = 0.003), whereas PSA declined in 27% and 14% (P = 0.160). Mean tALP change from baseline was 32.2% decrease with radium-223 and 37.2% increase with placebo. Radium-223 patients with tALP decline from baseline to week 12 (confirmed ≥3 weeks from week 12) had 55% lower risk of death (hazard ratio = 0.45; 95% CI 0.34–0.61) versus those with no confirmed tALP decline. Proportional treatment effect (PTE) values for tALP, LDH, and PSA changes from baseline at week 12 as OS surrogate markers were 0.34 (95% CI: 0–0.746), 0.07 (95% CI: 0–0.211), and 0 (95% CI: 0–0.082), respectively. Conclusions Significant tALP declines (versus placebo) occurred as early as 4 weeks after beginning radium-223 therapy. tALP or LDH declines at 12 weeks correlated with longer OS, but did not meet statistical surrogacy requirements. Dynamic changes in tALP and LDH during

  19. Lactate Clearance and Normalization and Prolonged Organ Dysfunction in Pediatric Sepsis.

    PubMed

    Scott, Halden F; Brou, Lina; Deakyne, Sara J; Fairclough, Diane L; Kempe, Allison; Bajaj, Lalit

    2016-03-01

    To evaluate whether lactate clearance and normalization during emergency care of pediatric sepsis is associated with lower rates of persistent organ dysfunction. This was a prospective cohort study of 77 children <18 years of age in the emergency department with infection and acute organ dysfunction per consensus definitions. In consented patients, lactate was measured 2 and/or 4 hours after an initial lactate; persistent organ dysfunction was assessed through laboratory and physician evaluation at 48 hours. A decrease of ≥ 10% from initial to final level was considered lactate clearance; a final level < 2 mmol/L was considered lactate normalization. Relative risk (RR) with 95% CIs, adjusted in a log-binomial model, was used to evaluate associations between lactate clearance/normalization and organ dysfunction. Lactate normalized in 62 (81%) patients and cleared in 70 (91%). The primary outcome, persistent 48-hour organ dysfunction, was present in 32 (42%). Lactate normalization was associated with decreased risk of persistent organ dysfunction (RR 0.46, 0.29-0.73; adjusted RR 0.47, 0.29-0.78); lactate clearance was not (RR 0.70, 0.35-1.41; adjusted RR 0.75, 0.38-1.50). The association between lactate normalization and decreased risk of persistent organ dysfunction was retained in the subgroups with initial lactate ≥ 2 mmol/L and hypotension. In children with sepsis and organ dysfunction, lactate normalization within 4 hours was associated with decreased persistent organ dysfunction. Serial lactate level measurement may provide a useful prognostic tool during the first hours of resuscitation in pediatric sepsis. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Exogenous lactate supply affects lactate kinetics of rainbow trout, not swimming performance

    PubMed Central

    Omlin, Teye; Langevin, Karolanne

    2014-01-01

    Intense swimming causes circulatory lactate accumulation in rainbow trout because lactate disposal (Rd) is not stimulated as strongly as lactate appearance (Ra). This mismatch suggests that maximal Rd is limited by tissue capacity to metabolize lactate. This study uses exogenous lactate to investigate what constrains maximal Rd and minimal Ra. Our goals were to determine how exogenous lactate affects: 1) Ra and Rd of lactate under baseline conditions or during graded swimming, and 2) exercise performance (critical swimming speed, Ucrit) and energetics (cost of transport, COT). Results show that exogenous lactate allows swimming trout to boost maximal Rd lactate by 40% and reach impressive rates of 56 μmol·kg−1·min−1. This shows that the metabolic capacity of tissues for lactate disposal is not responsible for setting the highest Rd normally observed after intense swimming. Baseline endogenous Ra (resting in normoxic water) is not significantly reduced by exogenous lactate supply. Therefore, trout have an obligatory need to produce lactate, either as a fuel for oxidative tissues and/or from organs relying on glycolysis. Exogenous lactate does not affect Ucrit or COT, probably because it acts as a substitute for glucose and lipids rather than extra fuel. We conclude that the observed 40% increase in Rd lactate is made possible by accelerating lactate entry into oxidative tissues via monocarboxylate transporters (MCTs). This observation together with the weak expression of MCTs and the phenomenon of white muscle lactate retention show that lactate metabolism of rainbow trout is significantly constrained by transmembrane transport. PMID:25121611

  1. Plasmodium glyceraldehyde-3-phosphate dehydrogenase: A potential malaria diagnostic target.

    PubMed

    Krause, Robert G E; Hurdayal, Ramona; Choveaux, David; Przyborski, Jude M; Coetzer, Theresa H T; Goldring, J P Dean

    2017-08-01

    Malaria rapid diagnostic tests (RDTs) are immunochromatographic tests detecting Plasmodial histidine-rich protein 2 (HRP2), lactate dehydrogenase (LDH) and aldolase. HRP2 is only expressed by Plasmodium falciparum parasites and the protein is not expressed in several geographic isolates. LDH-based tests lack sensitivity compared to HRP2 tests. This study explored the potential of the Plasmodial glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), as a new malaria diagnostic biomarker. The P. falciparum and P. yoelii proteins were recombinantly expressed in BL21(DE3) Escherischia coli host cells and affinity purified. Two epitopes (CADGFLLIGEKKVSVFA and CAEKDPSQIPWGKCQV) specific to P. falciparum GAPDH and one common to all mammalian malaria species (CKDDTPIYVMGINH) were identified. Antibodies were raised in chickens against the two recombinant proteins and the three epitopes and affinity purified. The antibodies detected the native protein in parasite lysates as a 38 kDa protein and immunofluorescence verified a parasite cytosolic localization for the native protein. The antibodies suggested a 4-6 fold higher concentration of native PfGAPDH compared to PfLDH in immunoprecipitation and ELISA formats, consistent with published proteomic data. PfGAPDH shows interesting potential as a malaria diagnostic biomarker. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Increased IMP dehydrogenase gene expression in solid tumor tissues and tumor cell lines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Collart, F.R.; Chubb, C.B.; Mirkin, B.L.

    1992-07-10

    IMP dehydrogenase, a regulatory enzyme of guanine nucleotide biosynthesis, may play a role in cell proliferation and malignancy. To assess this possibility, we examined IMP dehydrogenase expression in a series of human solid tumor tissues and tumor cell lines in comparison with their normal counterparts. Increased IMP dehydrogenase gene expression was observed in brain tumors relative to normal brain tissue and in sarcoma cells relative to normal fibroblasts. Similarly, in several B- and T-lymphoid leukemia cell lines, elevated levels of IMP dehydrogenase mRNA and cellular enzyme were observed in comparison with the levels in peripheral blood lymphocytes. These results aremore » consistent with an association between increased IMP dehydrogenase expression and either enhanced cell proliferation or malignant transformation.« less

  3. Lactation and reproduction*

    PubMed Central

    Thomson, A. M.; Hytten, F. E.; Black, A. E.

    1975-01-01

    The authors review the literature on the effect of lactation on fertility in the absence of contraception and on the effects of contraceptive measures on lactation. They examine data from several countries on the intervals between births and on the return of menstruation and ovulation after childbirth, comparing lactating with nonlactating women. They conclude that lactation is an inefficient contraceptive for the individual, but that in populations sustained lactation is associated with reduced fertility. Possible physiological mechanisms causing lactation amenorrhoea are discussed. Though much of the literature on the effect of contraceptives on lactation is inadequate, there is general agreement that the estrogen component of hormonal preparations has an adverse effect on lactation, but that progestins alone do not. Many questions remain. Is this effect seen in established lactation, or only in the puerperal period? Is it a direct pharmacological effect, or are pill-users the mothers least motivated to maintain breast-feeding? Does a close relationship exist between hormones given and lactation performance? The authors comment on some of the technical deficiencies of previous studies in this field and discuss practical possibilities of, and limitations to, obtaining adequate scientific information in the future. PMID:1084804

  4. Lactate clearance as a marker of mortality in pediatric intensive care unit.

    PubMed

    Munde, A; Kumar, N; Beri, R S; Puliyel, J M

    2014-07-01

    To correlate lactate clearance with Pediatric Intensive Care Unit (PICU) mortality. 45 (mean age 40.15 mo, 60% males) consecutive admissions in the PICU were enrolled between May 2012 to June 2013. Lactate clearance (Lactate level at admission - level 6 hr later x 100 / lactate level at admission) in first 6 hours of hospitalization was correlated to in-hospital mortality and PRISM score. Twelve out of 45 patients died. 90% died among those with delayed/poor clearance (clearance <30%) compared to 8.5% in those with good clearance (clearance >30%) (P<0.001). Lactate clearance <30% predicted mortality with sensitivity of 75%, specificity of 97%, positive predictive value of 90%, and negative predictive value of 91.42%. Predictability was comparable to PRISM score >30. Lactate clearance at six hours correlates with mortality in the PICU.

  5. Kinetics of lactate metabolism during acellular normothermic ex vivo lung perfusion.

    PubMed

    Koike, Terumoto; Yeung, Jonathan C; Cypel, Marcelo; Rubacha, Matthew; Matsuda, Yasushi; Sato, Masaaki; Waddell, Thomas K; Liu, Mingyao; Keshavjee, Shaf

    2011-12-01

    Plasma lactate has been used as a marker of poor prognosis in clinical conditions. However, the relationship between lactate production and lung function during acellular normothermic ex vivo lung perfusion (EVLP) is unclear. We investigated the kinetics of lactate metabolism during EVLP and the correlation of this marker with outcomes after transplant. Human donor lungs in our clinical EVLP trial (CLs; n = 28) and rejected donor lungs for experimental use (Els; n = 8) were perfused ex vivo using the Toronto technique. Lactate level, lactate/pyruvate (L/P) ratio, and glucose level in the perfusate were measured. In CLs, we examined the relationship between lactate metabolism during EVLP and early post-transplant outcomes. The hypoxia-inducible factor 1 sub-unit 1α (HIF-1α) level in lung tissue was examined in ELs. We performed double-lung EVLP in CLs and single-lung EVLP in ELs. In CLs, the lactate and L/P ratios at the end of EVLP had no correlation with early post-transplant outcomes despite lactate elevation during EVLP. Although lactate elevation was also present in all ELs, we were able to identify 2 groups based on L/P ratio at the end of EVLP. The group with the high L/P ratio had higher airway pressure during EVLP and higher HIF-1α in lung tissue at the end of EVLP. Lactate increases seen in the EVLP perfusate most often represent physiologic lactate production by the lung in a setting with reduced lactate clearance. Thus, patients who underwent transplantation after EVLP had good outcomes despite lactate elevation during EVLP. Copyright © 2011 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Lactate dehydrogenase test

    MedlinePlus

    Normal value range is 105 to 333 international units per liter (IU/L). Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about ...

  7. Lactate dehydrogenase predicts combined progression-free survival after sequential therapy with abiraterone and enzalutamide for patients with castration-resistant prostate cancer.

    PubMed

    Mori, Keiichiro; Kimura, Takahiro; Onuma, Hajime; Kimura, Shoji; Yamamoto, Toshihiro; Sasaki, Hiroshi; Miki, Jun; Miki, Kenta; Egawa, Shin

    2017-07-01

    An array of clinical issues remains to be resolved for castration-resistant prostate cancer (CRPC), including the sequence of drug use and drug cross-resistance. At present, no clear guidelines are available for the optimal sequence of use of novel agents like androgen-receptor axis-targeted (ARAT) agents, particularly enzalutamide, and abiraterone. This study retrospectively analyzed a total of 69 patients with CRPC treated with sequential therapy using enzalutamide followed by abiraterone or vice versa. The primary outcome measure was the comparative combined progression-free survival (PFS) comprising symptomatic and/or radiographic PFS. Patients were also compared for total prostate-specific antigen (PSA)-PFS, overall survival (OS), and PSA response. The predictors of combined PFS and OS were analyzed with a backward-stepwise multivariate Cox model. Of the 69 patients, 46 received enzalutamide first, followed by abiraterone (E-A group), and 23 received abiraterone, followed by enzalutamide (A-E group). The two groups were not significantly different with regard to basic data, except for hemoglobin values. In a comparison with the E-A group, the A-E group was shown to be associated with better combined PFS in Kaplan-Meier analysis (P = 0.043). Similar results were obtained for total PSA-PFS (P = 0.049), while OS did not differ between groups (P = 0.62). Multivariate analysis demonstrated that pretreatment lactate dehydrogenase (LDH) values and age were significant predictors of longer combined PFS (P < 0.05). Likewise, multivariate analysis demonstrated that pretreatment hemoglobin values and performance status were significant predictors of longer OS (P < 0.05). The results of this study suggested the A-E sequence had longer combined PSA and total PSA-PFS compared to the E-A sequence in patients with CRPC. LDH values in sequential therapy may serve as a predictor of longer combined PFS. © 2017 Wiley Periodicals, Inc.

  8. Brain lactate metabolism: the discoveries and the controversies

    PubMed Central

    Dienel, Gerald A

    2012-01-01

    Potential roles for lactate in the energetics of brain activation have changed radically during the past three decades, shifting from waste product to supplemental fuel and signaling molecule. Current models for lactate transport and metabolism involving cellular responses to excitatory neurotransmission are highly debated, owing, in part, to discordant results obtained in different experimental systems and conditions. Major conclusions drawn from tabular data summarizing results obtained in many laboratories are as follows: Glutamate-stimulated glycolysis is not an inherent property of all astrocyte cultures. Synaptosomes from the adult brain and many preparations of cultured neurons have high capacities to increase glucose transport, glycolysis, and glucose-supported respiration, and pathway rates are stimulated by glutamate and compounds that enhance metabolic demand. Lactate accumulation in activated tissue is a minor fraction of glucose metabolized and does not reflect pathway fluxes. Brain activation in subjects with low plasma lactate causes outward, brain-to-blood lactate gradients, and lactate is quickly released in substantial amounts. Lactate utilization by the adult brain increases during lactate infusions and strenuous exercise that markedly increase blood lactate levels. Lactate can be an ‘opportunistic', glucose-sparing substrate when present in high amounts, but most evidence supports glucose as the major fuel for normal, activated brain. PMID:22186669

  9. The Deletion of the Succinate Dehydrogenase Gene KlSDH1 in Kluyveromyces lactis Does Not Lead to Respiratory Deficiency

    PubMed Central

    Saliola, Michele; Bartoccioni, Paola Chiara; De Maria, Ilaria; Lodi, Tiziana; Falcone, Claudio

    2004-01-01

    We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose. PMID:15189981

  10. Bisphenol S Alters the Lactating Mammary Gland and Nursing Behaviors in Mice Exposed During Pregnancy and Lactation.

    PubMed

    LaPlante, Charlotte D; Catanese, Mary C; Bansal, Ruby; Vandenberg, Laura N

    2017-10-01

    High doses of estrogenic pharmaceuticals were once prescribed to women to halt lactation. Yet, the effects of low-level xenoestrogens on lactation remain poorly studied. We investigated the effects of bisphenol S (BPS), an estrogen receptor (ER) agonist, on the lactating mammary gland; the arcuate nucleus, a region of the hypothalamus important for neuroendocrine control of lactational behaviors; and nursing behavior in CD-1 mice. Female mice were exposed to vehicle, 2 or 200 µg BPS/kg/d from pregnancy day 9 until lactational day (LD) 20, and tissues were collected on LD21. Tissues were also collected from a second group at LD2. BPS exposure significantly reduced the fraction of the mammary gland comprised of lobules, the milk-producing units, on LD21, but not LD2. BPS also altered expression of Esr1 and ERα in the mammary gland at LD21, consistent with early involution. In the arcuate nucleus, no changes were observed in expression of signal transducer and activator of transcription 5, a marker of prolactin signaling, or ERα, suggesting that BPS may act directly on the mammary gland. However, observations of nursing behavior collected during the lactational period revealed stage-specific effects on both pup and maternal nursing behaviors; BPS-treated dams spent significantly more time nursing later in the lactational period, and BPS-treated pups were less likely to initiate nursing. Pup growth and development were also stunted. These data indicate that low doses of BPS can alter lactational behaviors and the maternal mammary gland. Together, they support the hypothesis that pregnancy and lactation are sensitive to low-dose xenoestrogen exposures. Copyright © 2017 Endocrine Society.

  11. The clinical diagnostic significance of cerebrospinal fluid D-lactate for bacterial meningitis.

    PubMed

    Chen, Zengqiang; Wang, Yumin; Zeng, Aibing; Chen, Lijiang; Wu, Ruihao; Chen, Bicheng; Chen, Mengquan; Bo, Jinshuang; Zhang, Hu; Peng, Qian; Lu, Jianxin; Meng, Qing H

    2012-10-09

    To study the clinical and laboratory significance of D‐lactate in the diagnosis of bacterial meningitis (BM). The levels of D‐lactate, L‐lactate, IL-6, IL-8, and other biochemical markers were determined in 83 CSF samples from different types of meningitis and the controls. The CSF values of D‐lactate, L‐lactate, IL-6, IL-8, erythrocytes, leukocytes, and protein were higher in patients with BM than those in the controls and patients with viral meningitis. The levels of D‐lactate, L‐lactate, IL-6, and erythrocytes in the BM group were higher than those in the tuberculous meningitis group. At the cutoff 12.8 μmol/l, D‐lactate showed the diagnostic sensitivity of 94.7%. D‐lactate gave the area under the curve (AUC) 0.905, which was higher than those of other markers. Using multiple marker detection, the AUC reached 0.956, which was the highest among all the parameters. Pearson correlation analysis revealed that D‐lactate was positively correlated to IL-6 and L‐lactate (r=0.727, 0.789 and P=0.000, 0.000, respectively). THE CSF concentrations of D‐lactate are significantly increased in the presence of BM. Measurement of D‐lactate provides a rapid diagnosis and differential diagnosis for BM. Combination of D‐lactate with other biochemical markers improves the specificity. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Lactate Parameters Predict Clinical Outcomes in Patients with Nonvariceal Upper Gastrointestinal Bleeding.

    PubMed

    Lee, Seung Hoon; Min, Yang Won; Bae, Joohwan; Lee, Hyuk; Min, Byung Hoon; Lee, Jun Haeng; Rhee, Poong Lyul; Kim, Jae J

    2017-11-01

    The predictive role of lactate in patients with nonvariceal upper gastrointestinal bleeding (NVUGIB) has been suggested. This study evaluated several lactate parameters in terms of predicting outcomes of bleeding patients and sought to establish a new scoring model by combining lactate parameters and the AIMS65 score. A total of 114 patients with NVUGIB who underwent serum lactate level testing at least twice and endoscopic hemostasis within 24 hours after admission were retrospectively analyzed. The associations between five lactate parameters and clinical outcomes were evaluated and the predictive power of lactate parameter combined AIMS65s (L-AIMS65s) and AIMS56 scoring was compared. The most common cause of bleeding was gastric ulcer (48.2%). Lactate clearance rate (LCR) was associated with 30-day rebleeding (odds ratio [OR], 0.931; 95% confidence interval [CI], 0.872-0.994; P = 0.033). Initial lactate (OR, 1.313; 95% CI, 1.050-1.643; P = 0.017), maximal lactate (OR, 1.277; 95% CI, 1.037-1.573; P = 0.021), and average lactate (OR, 1.535; 95% CI, 1.137-2.072; P = 0.005) levels were associated with 30-day mortality. Initial lactate (OR, 1.213; 95% CI, 1.027-1.432; P = 0.023), maximal lactate (OR, 1.271; 95% CI, 1.074-1.504; P = 0.005), and average lactate (OR, 1.501; 95% CI, 1.150-1.959; P = 0.003) levels were associated with admission over 7 days. Although L-AIMS65s showed the highest area under the curve for prediction of each outcome, differences between L-AIMS65s and AIMS65 did not reach statistical significance. In conclusion, lactate parameters have a prognostic role in patients with NVUGIB. However, they do not increase the predictive power of AIMS65 when combined. © 2017 The Korean Academy of Medical Sciences.

  13. Safety of single low-dose primaquine in glucose-6-phosphate dehydrogenase deficient falciparum-infected African males: Two open-label, randomized, safety trials

    PubMed Central

    Pett, Helmi E.; Coulibaly, Sam A.; Gonçalves, Bronner P.; Affara, Muna; Ouédraogo, Alphonse; Bougouma, Edith C.; Sanou, Guillaume S.; Nébié, Issa; Bradley, John; Lanke, Kjerstin H. W.; Niemi, Mikko; Sirima, Sodiomon B.; d’Alessandro, Umberto; Bousema, Teun; Drakeley, Chris

    2018-01-01

    Background Primaquine (PQ) actively clears mature Plasmodium falciparum gametocytes but in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals can cause hemolysis. We assessed the safety of low-dose PQ in combination with artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DP) in G6PDd African males with asymptomatic P. falciparum malaria. Methods and findings In Burkina Faso, G6PDd adult males were randomized to treatment with AL alone (n = 10) or with PQ at 0.25 (n = 20) or 0.40 mg/kg (n = 20) dosage; G6PD-normal males received AL plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. In The Gambia, G6PDd adult males and boys received DP alone (n = 10) or with 0.25 mg/kg PQ (n = 20); G6PD-normal males received DP plus 0.25 (n = 10) or 0.40 mg/kg (n = 10) PQ. The primary study endpoint was change in hemoglobin concentration during the 28-day follow-up. Cytochrome P-450 isoenzyme 2D6 (CYP2D6) metabolizer status, gametocyte carriage, haptoglobin, lactate dehydrogenase levels and reticulocyte counts were also determined. In Burkina Faso, the mean maximum absolute change in hemoglobin was -2.13 g/dL (95% confidence interval [CI], -2.78, -1.49) in G6PDd individuals randomized to 0.25 PQ mg/kg and -2.29 g/dL (95% CI, -2.79, -1.79) in those receiving 0.40 PQ mg/kg. In The Gambia, the mean maximum absolute change in hemoglobin concentration was -1.83 g/dL (95% CI, -2.19, -1.47) in G6PDd individuals receiving 0.25 PQ mg/kg. After adjustment for baseline concentrations, hemoglobin reductions in G6PDd individuals in Burkina Faso were more pronounced compared to those in G6PD-normal individuals receiving the same PQ doses (P = 0.062 and P = 0.022, respectively). Hemoglobin levels normalized during follow-up. Abnormal haptoglobin and lactate dehydrogenase levels provided additional evidence of mild transient hemolysis post-PQ. Conclusions Single low-dose PQ in combination with AL and DP was associated with mild and transient reductions in hemoglobin. None of the

  14. [Breast-feeding (part II): Lactation inhibition--Guidelines for clinical practice].

    PubMed

    Marcellin, L; Chantry, A A

    2015-12-01

    Provide guidelines for clinical use of non-pharmacological and pharmacological treatments of inhibition of lactation and the management of the weaning. Systematically review of the literature between 1972 and May 2015 from the databases Medline, Google Scholar, Cochrane Library, and the international recommendations about inhibition of lactation with establishment of levels of evidence (LE) and grades of recommendation. The available data on the effectiveness of non-pharmacological measures are limited, with very low levels of evidence that fail to make recommendations (Professional consensus). Pharmacological treatments for inhibition of lactation should not be given routinely to women who do not wish to breast-feed (Professional consensus). For women aware of the risks of pharmacological treatments of inhibition of lactation, lisuride and cabergolin are the preferred drugs (Professional consensus). Because of potentially serious adverse effects, bromocriptin is contraindicated in inhibiting lactation (Professional consensus). Available data on management of lactation weaning fail to provide recommendation and no treatment is recommended (Professional consensus). Bromocriptin is contraindicated in the treatment of inhibiting lactation. Women who do not wish to breast-feed have to be informed of the benefits and disadvantages of the pharmacological treatment for inhibition of lactation. Copyright © 2015. Published by Elsevier Masson SAS.

  15. Lactate transport and receptor actions in cerebral malaria

    PubMed Central

    Mariga, Shelton T.; Kolko, Miriam; Gjedde, Albert; Bergersen, Linda H.

    2014-01-01

    Cerebral malaria (CM), caused by Plasmodium falciparum infection, is a prevalent neurological disorder in the tropics. Most of the patients are children, typically with intractable seizures and high mortality. Current treatment is unsatisfactory. Understanding the pathogenesis of CM is required in order to identify therapeutic targets. Here, we argue that cerebral energy metabolic defects are probable etiological factors in CM pathogenesis, because malaria parasites consume large amounts of glucose metabolized mostly to lactate. Monocarboxylate transporters (MCTs) mediate facilitated transfer, which serves to equalize lactate concentrations across cell membranes in the direction of the concentration gradient. The equalizing action of MCTs is the basis for lactate’s role as a volume transmitter of metabolic signals in the brain. Lactate binds to the lactate receptor GPR81, recently discovered on brain cells and cerebral blood vessels, causing inhibition of adenylyl cyclase. High levels of lactate delivered by the parasite at the vascular endothelium may damage the blood–brain barrier, disrupt lactate homeostasis in the brain, and imply MCTs and the lactate receptor as novel therapeutic targets in CM. PMID:24904266

  16. Chronic alcoholism in rats induces a compensatory response, preserving brain thiamine diphosphate, but the brain 2-oxo acid dehydrogenases are inactivated despite unchanged coenzyme levels.

    PubMed

    Parkhomenko, Yulia M; Kudryavtsev, Pavel A; Pylypchuk, Svetlana Yu; Chekhivska, Lilia I; Stepanenko, Svetlana P; Sergiichuk, Andrej A; Bunik, Victoria I

    2011-06-01

    Thiamine-dependent changes in alcoholic brain were studied using a rat model. Brain thiamine and its mono- and diphosphates were not reduced after 20 weeks of alcohol exposure. However, alcoholism increased both synaptosomal thiamine uptake and thiamine diphosphate synthesis in brain, pointing to mechanisms preserving thiamine diphosphate in the alcoholic brain. In spite of the unchanged level of the coenzyme thiamine diphosphate, activities of the mitochondrial 2-oxoglutarate and pyruvate dehydrogenase complexes decreased in alcoholic brain. The inactivation of pyruvate dehydrogenase complex was caused by its increased phosphorylation. The inactivation of 2-oxoglutarate dehydrogenase complex (OGDHC) correlated with a decrease in free thiols resulting from an elevation of reactive oxygen species. Abstinence from alcohol following exposure to alcohol reactivated OGDHC along with restoration of the free thiol content. However, restoration of enzyme activity occurred before normalization of reactive oxygen species levels. Hence, the redox status of cellular thiols mediates the action of oxidative stress on OGDHC in alcoholic brain. As a result, upon chronic alcohol consumption, physiological mechanisms to counteract the thiamine deficiency and silence pyruvate dehydrogenase are activated in rat brain, whereas OGDHC is inactivated due to impaired antioxidant ability. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

  17. [NUCLEAR STRUCTURE IN THE SECRETORY CELLS OF MAMMARY GLANDS IN LACTATING AND NON-LACTATING RATS].

    PubMed

    Tyutina, K V; Skopichev, V G; Bogolyubov, D S; Bogolyubova, I O

    2016-01-01

    The features of structural and functional organization of the main nuclear compartments and distribution of their key molecular components (chromatin-remodeling protein ATRX, RNA polymerase I and II, and the splicing factor SC35) has been studied in the nuclei of mammary gland cells at different functional states. No significant differences between the nuclei of the cells in the lactating and non-lactating mammary glands have been revealed at the ultrastructural level. At the same time, photometric analysis has revealed higher intensity of nucleoplasmic immunofluorescent staining of mammary glands in the lactating animals when antibodies against the proteins ATRX and SC35 were used. Apparently, this observation reflects the changes of the structural and functional status of chromatin as well as the redistribution of splicing factors between the sites of their deposition and transcription.

  18. Effects of high and low blood lactate concentrations on sweat lactate response.

    PubMed

    Green, J M; Bishop, P A; Muir, I H; McLester, J R; Heath, H E

    2000-11-01

    Sweat lactate results from eccrine gland metabolism, however, the possible clearance of blood lactate through sweat has not been resolved. On separate days in an environmental chamber (32 +/- 1 C) 12 subjects completed a constant load (CON) (30 min at 40% VO2 max) and an interval cycling trial (INT) (15 one-min intervals at 80% VO2 max, each separated by one min rest) each designed to elicit different blood lactate responses. Each 30 min cycling trial was preceded by 15 min warm-up (30 watts) and followed by 15 min passive rest. Sweat and blood were analyzed for lactate concentration at 15, 25, 35, 45, and 60 min during CON and INT. Total body water loss was used to calculate sweat rate (ml/hr). Blood lactate was significantly greater (p < or = 0.05) at 25, 35, 45, and 60 min during INT compared to CON (approximately 5 mmol/L vs 1.5 mmol/L). Sweat lactate was not significantly different (p>0.05) between trials at any time (approximately 10 mmol/L). Sweat rates (approximately 600ml/hr) and estimated total lactate secretion were not significantly different (CON vs. INT) (p > 0.05). Elevated blood lactate was not associated with changes in sweat lactate concentration. Sweat lactate seems to originate in eccrine glands independent of blood lactate.

  19. Improvement of L(+)-Lactic Acid Production of Rhizopus Oryzae by Low-Energy Ions and Analysis of Its Mechanism

    NASA Astrophysics Data System (ADS)

    Ge, Chunmei; Yang, Yingge; Fan, Yonghong; Li, Wen; Pan, Renrui; Zheng, Zhiming; Yu, Zengliang

    2008-02-01

    The wild type strain Rhizopus oryzae PW352 was mutated by means of nitrogen ion implantation (15 keV, 7.8 × 1014 ~ 2.08 × 1015 ions/cm2) to find an industrial strain with a higher L(+)-lactic acid yield, and two mutants RE3303 and RF9052 were isolated. In order to discuss the mechanism primarily, Lactate Dehydrogenase of Rhizopus oryzae was studied. While the two mutants produced L(+)-lactic acid by 75% more than the wild strain did, their specific activity of Lactate Dehydrogenase was found to be higher than that in the wild strain. The optimum temperature of Lactate Dehydrogenase in Rhizopus oryzae RF9052 was higher. Compared to the wild strain, the Michaelis constant (Km) value of Lactate Dehydrogenase in the mutants was changed. All these changes show that L(+)-lactic acid production has a correlation with the specific activity of Lactate Dehydrogenase. The low-energy ions, implanted into the strain, may improve the specific activity of Lactate Dehydrogenase by influencing its gene structure and protein structure.

  20. Lactate overrides central nervous but not beta-cell glucose sensing in humans.

    PubMed

    Schmid, Sebastian M; Jauch-Chara, Kamila; Hallschmid, Manfred; Oltmanns, Kerstin M; Peters, Achim; Born, Jan; Schultes, Bernd

    2008-12-01

    Lactate has been shown to serve as an alternative energy substrate in the central nervous system and to interact with hypothalamic glucose sensors. On the background of marked similarities between central nervous and beta-cell glucose sensing, we examined whether lactate also interacts with pancreatic glucose-sensing mechanisms in vivo. The effects of intravenously infused lactate vs placebo (saline) on central nervous and pancreatic glucose sensing were assessed during euglycemic and hypoglycemic clamp experiments in 10 healthy men. The release of neuroendocrine counterregulatory hormones during hypoglycemia was considered to reflect central nervous glucose sensing, whereas endogenous insulin secretion as assessed by serum C-peptide levels served as an indicator of pancreatic beta-cell glucose sensing. Lactate infusion blunted the counterregulatory hormonal responses to hypoglycemia, in particular, the release of epinephrine (P = .007) and growth hormone (P = .004), so that higher glucose infusion rates (P = .012) were required to maintain the target blood glucose levels. In contrast, the decrease in C-peptide concentrations during the hypoglycemic clamp remained completely unaffected by lactate (P = .60). During euglycemic clamp conditions, lactate infusion did not affect the concentrations of C-peptide and of counterregulatory hormones, with the exception of norepinephrine levels that were lower during lactate than saline infusion (P = .049) independently of the glycemic condition. Data indicate that glucose sensing of beta-cells is specific to glucose, whereas glucose sensing at the central nervous level can be overridden by lactate, reflecting the brain's ability to rely on lactate as an alternative major energy source.

  1. Bifunctional isocitrate-homoisocitrate dehydrogenase: a missing link in the evolution of beta-decarboxylating dehydrogenase.

    PubMed

    Miyazaki, Kentaro

    2005-05-27

    Beta-decarboxylating dehydrogenases comprise 3-isopropylmalate dehydrogenase, isocitrate dehydrogenase, and homoisocitrate dehydrogenase. They share a high degree of amino acid sequence identity and occupy equivalent positions in the amino acid biosynthetic pathways for leucine, glutamate, and lysine, respectively. Therefore, not only the enzymes but also the whole pathways should have evolved from a common ancestral pathway. In Pyrococcus horikoshii, only one pathway of the three has been identified in the genomic sequence, and PH1722 is the sole beta-decarboxylating dehydrogenase gene. The organism does not require leucine, glutamate, or lysine for growth; the single pathway might play multiple (i.e., ancestral) roles in amino acid biosynthesis. The PH1722 gene was cloned and expressed in Escherichia coli and the substrate specificity of the recombinant enzyme was investigated. It exhibited activities on isocitrate and homoisocitrate at near equal efficiency, but not on 3-isopropylmalate. PH1722 is thus a novel, bifunctional beta-decarboxylating dehydrogenase, which likely plays a dual role in glutamate and lysine biosynthesis in vivo.

  2. Breastfeeding and Prolactin Levels in Lactating Women With a Family History of Alcoholism

    PubMed Central

    Mennella, Julie A.; Pepino, Marta Yanina

    2010-01-01

    OBJECTIVE Many motivated new mothers fail to reach public health goals for breastfeeding, highlighting the need to identify risk factors. Because having a family history of alcoholism is associated with blunted prolactin responses to an alcohol challenge in nonlactating individuals, this study aimed to identify associations in family history of alcoholism, prolactin, and breastfeeding behaviors in lactating women. METHODS This was a 2-day experimental study that used within-subject alcohol or control beverage consumption and between-subject family history of alcoholism factors. The participants were non–alcohol-dependent lactating women; 7 were family history–positive (FHP) for alcohol dependence, and 21 were family history–negative (FHN). Consumption of 0.4 g/kg alcohol or nonalcoholic beverage occurred in separate randomized sessions, followed by use of a breast pump. Basal and suckling-induced prolactin, blood alcohol concentrations, milk yield, self-reported drug effects, neophobia, and breastfeeding patterning were measured. RESULTS Although no group differences in alcohol pharmacokinetics were detected, FHP women exhibited blunted prolactin to breast stimulation after drinking the control and alcohol beverage and felt more of the stimulant-like effects of alcohol than did FHN women. FHP women reported more frequent daily breastfeeding than did FHN women. CONCLUSIONS This is the first evidence that family history of alcoholism is associated with a blunted magnitude, rapidity, and duration of the prolactin response to breast stimulation and an alcohol challenge in lactating women. More frequent breastfeeding by FHP women suggests behavioral compensation for perceived and/or actual poor lactation. Alcohol did not enhance lactational performance, further disputing the lore that alcohol is a galactagogue. PMID:20403941

  3. Isolation, sequence, and characterization of the Cercospora nicotianae phytoene dehydrogenase gene.

    PubMed Central

    Ehrenshaft, M; Daub, M E

    1994-01-01

    We have cloned and sequenced the Cercospora nicotianae gene for the carotenoid biosynthetic enzyme phytoene dehydrogenase. Analysis of the derived amino acid sequence revealed it has greater than 50% identity with its counterpart in Neurospora crassa and approximately 30% identity with prokaryotic phytoene dehydrogenases and is related, but more distantly, to phytoene dehydrogenases from plants and cyanobacteria. Our analysis confirms that phytoene dehydrogenase proteins fall into two groups: those from plants and cyanobacteria and those from eukaryotic and noncyanobacter prokaryotic microbes. Southern analysis indicated that the C. nicotianae phytoene dehydrogenase gene is present in a single copy. Extraction of beta-carotene, the sole carotenoid accumulated by C. nicotianae, showed that both light- and dark-grown cultures synthesize carotenoids, but higher levels accumulate in the light. Northern (RNA) analysis of poly(A)+ RNA, however, showed no differential accumulation of phytoene dehydrogenase mRNA between light- and dark-grown fungal cultures. Images PMID:8085820

  4. Disposable electrochemiluminescent biosensor for lactate determination in saliva.

    PubMed

    Ballesta Claver, J; Valencia Mirón, M C; Capitán-Vallvey, L F

    2009-07-01

    An electrochemiluminescence-based disposable biosensor for lactate is characterized. The lactate recognition system is based on lactate oxidase (LOx) and the transduction system consists of luminol. All the needed reagents, luminol, LOx, BSA, electrolyte and buffer have been immobilized by a Methocel membrane placed on the working electrode of the screen-printed electrochemical cell. The measurement of the electrochemiluminescence (ECL) is made possible via a photocounting head when 50 microl of sample is placed into the screen-printed cell with a circular container containing the disposable sensing membrane. The compositions of the membrane and reaction conditions have been optimized to obtain adequate sensitivity. The disposable biosensor responds to lactate after 20 s when two 1 s pulses at 0.5 V are applied to obtain the analytical parameter, the ECL initial rate. The linearized double logarithmic dependence for lactate shows a dynamic range from 10(-5) to 5 x 10(-4) M with a detection limit of 5 x 10(-6) M and a sensor-to-sensor repeatability, as relative standard deviation, RSD, of 3.30% at the medium level of the range. The ECL disposable biosensor was applied to the analysis of lactate in human saliva as an alternative procedure for obtaining the lactate level in a non-invasive way. Interferences coming from components of saliva were studied and eliminated in a simple way that was easy to handle. The procedure was validated for use in human saliva, comparing the results against an enzymatic reference procedure. The proposed method is quick, inexpensive, selective and sensitive and uses conventional ECL instrumentation.

  5. Biochemical identification of the mallard, Anas platyrhynchos, and black duck, A. rubripes

    USGS Publications Warehouse

    Morgan, R.P.; Noe, L.A.; Henny, C.J.

    1976-01-01

    1. Eleven tissue systems from mallards and black ducks were examined for soluble proteins, lactate dehydrogenases and non-specific esterases through discontinuous polyacrylamide techniques.2. Biochemical relationships between the black duck and mallard are extremely similar.3. Hemoglobins and lactate dehydrogenase appear to be common in electrophoretic mobility between the two species.4. Approximately 89% of the soluble proteins and 58% of the non-specific esterases are common among the two species, indicating both biochemical similarity at the genus level and species-specificity.

  6. Effect of whole body vibration on lactate level recovery and heart rate recovery in rest after intense exercise.

    PubMed

    Kang, Seung Rok; Min, Jin-Young; Yu, Changho; Kwon, Tae-Kyu

    2017-07-20

    In this paper, we investigated the recovery of the lactate level, muscular fatigue, and heart rate recovery (HRR) with respect to whole body vibration (WBV) during the rest stage after a gait exercise. A total of 24 healthy subjects with no medical history of exercise injury participated. The participants were divided into a training group with vibration during rest and a control group with the same conditions but without vibration. The subjects performed a gait exercise with a slope of 15% and velocity of 4 km/h to consume 450 kcal in 30 min. Then, they rested on a vibrating chair or on a chair without vibrations for 30 min. The vibration protocol consists of a frequency of 10 Hz and amplitude of 5 mm. To estimate the recovery effect, we measured the lactate levels in blood, spectral edge frequency (SEF) of MVIC, and HRR before, immediately after exercise, and after rest. The results showed that the lactate level in the training group decreased more (93.8%) than in the control group (32.8%). Also, HRR showed a similar trend with a recovery of 88.39% in the training group but 64.72% in the control group. We considered that whole-body vibrations during rest would help remove lactic acid by improving the level of lactic acid oxidation with stimulated blood vessels in the muscles and by helping to maintain blood flow. Also, WBV would lead to compensation to actively decrease the fast excess post-exercise oxygen consumption from blood circulation. We suggest that whole-body vibrations during rest can provide fast, efficient fatigue recovery as a cool down exercise for women, the elderly, and patients without other activity after intense exercise.

  7. Proteomic analysis of physiological function response to hot summer in liver from lactating dairy cows.

    PubMed

    Wang, Qiangjun; Zhao, Xiaowei; Zhang, Zijun; Zhao, Huiling; Huang, Dongwei; Cheng, Guanglong; Yang, Yongxin

    2017-04-01

    Lactation performance of dairy cattle is susceptible to heat stress. The liver is one of the most crucial organs affected by high temperature in dairy cows. However, the physiological adaption by the liver to hot summer conditions has not been well elucidated in lactating dairy cows. In the present study, proteomic analysis of the liver in dairy cows in spring and hot summer was performed using a label-free method. In total, 127 differentially expressed proteins were identified; most of the upregulated proteins were involved in protein metabolic processes and responses to stimuli, whereas most of the downregulated proteins were related to oxidation-reduction. Pathway analysis indicated that 3 upregulated heat stress proteins (HSP90α, HSP90β, and endoplasmin) were enriched in the NOD-like receptor signaling pathway, whereas several downregulated NADH dehydrogenase proteins were involved in the oxidative phosphorylation pathway. The protein-protein interaction network indicated that several upregulated HSPs (HSP90α, HSP90β, and GRP78) were involved in more interactions than other proteins and were thus considered as central hub nodes. Our findings provide novel insights into the physiological adaption of liver function in lactating dairy cows to natural high temperature. Copyright © 2017. Published by Elsevier Ltd.

  8. Single mutation in Shine-Dalgarno-like sequence present in the amino terminal of lactate dehydrogenase of Plasmodium effects the production of an eukaryotic protein expressed in a prokaryotic system.

    PubMed

    Cicek, Mustafa; Mutlu, Ozal; Erdemir, Aysegul; Ozkan, Ebru; Saricay, Yunus; Turgut-Balik, Dilek

    2013-06-01

    One of the most important step in structure-based drug design studies is obtaining the protein in active form after cloning the target gene. In one of our previous study, it was determined that an internal Shine-Dalgarno-like sequence present just before the third methionine at N-terminus of wild type lactate dehydrogenase enzyme of Plasmodium falciparum prevent the translation of full length protein. Inspection of the same region in P. vivax LDH, which was overproduced as an active enzyme, indicated that the codon preference in the same region was slightly different than the codon preference of wild type PfLDH. In this study, 5'-GGAGGC-3' sequence of P. vivax that codes for two glycine residues just before the third methionine was exchanged to 5'-GGAGGA-3', by mimicking P. falciparum LDH, to prove the possible effects of having an internal SD-like sequence when expressing an eukaryotic protein in a prokaryotic system. Exchange was made by site-directed mutagenesis. Results indicated that having two glycine residues with an internal SD-like sequence (GGAGGA) just before the third methionine abolishes the enzyme activity due to the preference of the prokaryotic system used for the expression. This study emphasizes the awareness of use of a prokaryotic system to overproduce an eukaryotic protein.

  9. Alcohol Dehydrogenase-1B (rs1229984) and Aldehyde Dehydrogenase-2 (rs671) Genotypes Are Strong Determinants of the Serum Triglyceride and Cholesterol Levels of Japanese Alcoholic Men.

    PubMed

    Yokoyama, Akira; Yokoyama, Tetsuji; Matsui, Toshifumi; Mizukami, Takeshi; Kimura, Mitsuru; Matsushita, Sachio; Higuchi, Susumu; Maruyama, Katsuya

    2015-01-01

    Elevated serum triglyceride (TG) and high-density-lipoprotein cholesterol (HDL-C) levels are common in drinkers. The fast-metabolizing alcohol dehydrogenase-1B encoded by the ADH1B*2 allele (vs. ADH1B*1/*1 genotype) and inactive aldehyde dehydrogenase-2 encoded by the ALDH2*2 allele (vs. ALDH2*1/*1 genotype) modify ethanol metabolism and are prevalent (≈90% and ≈40%, respectively) in East Asians. We attempted to evaluate the associations between the ADH1B and ALDH2 genotypes and lipid levels in alcoholics. The population consisted of 1806 Japanese alcoholic men (≥40 years) who had undergone ADH1B and ALDH2 genotyping and whose serum TG, total cholesterol, and HDL-C levels in the fasting state had been measured within 3 days after admission. High serum levels of TG (≥150 mg/dl), HDL-C (>80 mg/dl), and low-density-lipoprotein cholesterol (LDL-C calculated by the Friedewald formula ≥140 mg/dl) were observed in 24.3%, 16.8%, and 15.6%, respectively, of the subjects. Diabetes, cirrhosis, smoking, and body mass index (BMI) affected the serum lipid levels. Multivariate analysis revealed that the presence of the ADH1B*2 allele and the active ALDH2*1/*1 genotype increased the odds ratio (OR; 95% confidence interval) for a high TG level (2.22 [1.67-2.94] and 1.39 [0.99-1.96], respectively), and decreased the OR for a high HDL-C level (0.37 [0.28-0.49] and 0.51 [0.37-0.69], respectively). The presence of the ADH1B*2 allele decreased the OR for a high LDL-C level (0.60 [0.45-0.80]). The ADH1B*2 plus ALDH2*1/*1 combination yielded the highest ORs for high TG levels and lowest OR for a high HDL-C level. The genotype effects were more prominent in relation to the higher levels of TG (≥220 mg/dl) and HDL-C (≥100 mg/dl). The fast-metabolizing ADH1B and active ALDH2, and especially a combination of the two were strongly associated with higher serum TG levels and lower serum HDL-C levels of alcoholics. The fast-metabolizing ADH1B was associated with lower serum LDL

  10. Relationship between the degree of antioxidant protection and the level of malondialdehyde in high-performance Polish Holstein-Friesian cows in peak of lactation

    PubMed Central

    2018-01-01

    Lipid peroxidation can be described as a process under which free radicals attack carbon double bonds of omega-3 and omega-6 fatty acids. Whereas the end products of this process are reactive aldehydes, such as malondialdehyde (MDA). Lipid peroxidation leads to adverse changes in the nutritional value of milk; therefore, higher degree of antioxidant protection (DAP) ensures higher stability of dairy products by effecting their high antioxidative potential. Therefore, the purpose of this study was to demonstrate the relationship between the DAP and the level of MDA in high-performance Polish Holstein-Friesian cows in peak of lactation. Sixty-three Polish Holstein-Friesian cows were selected to the experiment according to: parity (all in the 2nd lactation), phase of lactation (peak of lactation), cytological quality of milk (somatic cell count < 150 thousand/ml) and without diagnosed metabolic diseases. The data obtained were analyzed statistically by two–way ANOVA, and Tukey’s post-hoc test. After analysis of performance the cows were divided into 3 groups (twenty one cows in each group) based on milk yield and MDA concentration. The study revealed a significant effect of the lactation performance of cows on MDA levels in milk (P ≤ 0.01). The highest concentration of MDA (61.137 nM/mL) was shown in milk of cows yielding between 50.00 and 55.80 kg/day. The highest concentration of fat was found in milk in which the MDA level ranged from 48 to 86 nM/mL. Whereas, the inverse relationship was demonstrated in case of protein concentration. The highest level of protein was found in cows with MDA levels in the range of 18–28 nM/mL (P ≤ 0.01). The lowest MDA level (in the range of 18–28 nM/mL) was associated with the highest concentration of vitamin E, β-carotene, total antioxidant status (TAS) and DAP, measured in both milk and plasma. The obtained results show that lipid peroxidation leads to adverse changes in the nutritional value of milk; the highest DAP

  11. Adaptive Activation of a Stress Response Pathway Improves Learning and Memory Through Gs and β-Arrestin-1-Regulated Lactate Metabolism.

    PubMed

    Dong, Jun-Hong; Wang, Yi-Jing; Cui, Min; Wang, Xiao-Jing; Zheng, Wen-Shuai; Ma, Ming-Liang; Yang, Fan; He, Dong-Fang; Hu, Qiao-Xia; Zhang, Dao-Lai; Ning, Shang-Lei; Liu, Chun-Hua; Wang, Chuan; Wang, Yue; Li, Xiang-Yao; Yi, Fan; Lin, Amy; Kahsai, Alem W; Cahill, Thomas Joseph; Chen, Zhe-Yu; Yu, Xiao; Sun, Jin-Peng

    2017-04-15

    Stress is a conserved physiological response in mammals. Whereas moderate stress strengthens memory to improve reactions to previously experienced difficult situations, too much stress is harmful. We used specific β-adrenergic agonists, as well as β 2 -adrenergic receptor (β2AR) and arrestin knockout models, to study the effects of adaptive β2AR activation on cognitive function using Morris water maze and object recognition experiments. We used molecular and cell biological approaches to elucidate the signaling subnetworks. We observed that the duration of the adaptive β2AR activation determines its consequences on learning and memory. Short-term formoterol treatment, for 3 to 5 days, improved cognitive function; however, prolonged β2AR activation, for more than 6 days, produced harmful effects. We identified the activation of several signaling networks downstream of β2AR, as well as an essential role for arrestin and lactate metabolism in promoting cognitive ability. Whereas Gs-protein kinase A-cyclic adenosine monophosphate response element binding protein signaling modulated monocarboxylate transporter 1 expression, β-arrestin-1 controlled expression levels of monocarboxylate transporter 4 and lactate dehydrogenase A through the formation of a β-arrestin-1/phospho-mitogen-activated protein kinase/hypoxia-inducible factor-1α ternary complex to upregulate lactate metabolism in astrocyte-derived U251 cells. Conversely, long-term treatment with formoterol led to the desensitization of β2ARs, which was responsible for its decreased beneficial effects. Our results not only revealed that β-arrestin-1 regulated lactate metabolism to contribute to β2AR functions in improved memory formation, but also indicated that the appropriate management of one specific stress pathway, such as through the clinical drug formoterol, may exert beneficial effects on cognitive abilities. Copyright © 2016 Society of Biological Psychiatry. All rights reserved.

  12. In Vivo Evidence for a Lactate Gradient from Astrocytes to Neurons.

    PubMed

    Mächler, Philipp; Wyss, Matthias T; Elsayed, Maha; Stobart, Jillian; Gutierrez, Robin; von Faber-Castell, Alexandra; Kaelin, Vincens; Zuend, Marc; San Martín, Alejandro; Romero-Gómez, Ignacio; Baeza-Lehnert, Felipe; Lengacher, Sylvain; Schneider, Bernard L; Aebischer, Patrick; Magistretti, Pierre J; Barros, L Felipe; Weber, Bruno

    2016-01-12

    Investigating lactate dynamics in brain tissue is challenging, partly because in vivo data at cellular resolution are not available. We monitored lactate in cortical astrocytes and neurons of mice using the genetically encoded FRET sensor Laconic in combination with two-photon microscopy. An intravenous lactate injection rapidly increased the Laconic signal in both astrocytes and neurons, demonstrating high lactate permeability across tissue. The signal increase was significantly smaller in astrocytes, pointing to higher basal lactate levels in these cells, confirmed by a one-point calibration protocol. Trans-acceleration of the monocarboxylate transporter with pyruvate was able to reduce intracellular lactate in astrocytes but not in neurons. Collectively, these data provide in vivo evidence for a lactate gradient from astrocytes to neurons. This gradient is a prerequisite for a carrier-mediated lactate flux from astrocytes to neurons and thus supports the astrocyte-neuron lactate shuttle model, in which astrocyte-derived lactate acts as an energy substrate for neurons. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Inhibition of Growth by Combined Treatment with Inhibitors of Lactate Dehydrogenase and either Phenformin or Inhibitors of 6-Phosphofructo-2-kinase/Fructose-2,6-bisphosphatase 3.

    PubMed

    Lea, Michael A; Guzman, Yolanda; Desbordes, Charles

    2016-04-01

    Enhanced glycolysis in cancer cells presents a target for chemotherapy. Previous studies have indicated that proliferation of cancer cells can be inhibited by treatment with phenformin and with an inhibitor of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB) namely 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO). In the present work, the action of two inhibitors that are effective at lower concentrations than 3PO, namely 1-(3-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PQP) and 1-(4-pyridinyl)-3-(2-quinolinyl)-2-propen-1-one (PFK15) were investigated. The inhibitors of lactate dehydrogenase (LDHA) studied in order of half-maximal inhibitory concentrations were methyl 1-hydroxy-6-phenyl-4-(trifluoromethyl)-1H-indole-2-carboxylate (NHI-2) < isosafrole < oxamate. In colonic and bladder cancer cells, additive growth inhibitory effects were seen with the LDHA inhibitors, of which NHI-2 was effective at the lowest concentrations. Growth inhibition was generally greater with PFK15 than with PQP. The increased acidification of the culture medium and glucose uptake caused by phenformin was blocked by combined treatment with PFKFB3 or LDHA inhibitors. The results suggest that combined treatment with phenformin and inhibitors of glycolysis can cause additive inhibition of cell proliferation and may mitigate lactic acidosis caused by phenformin when used as a single agent. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  14. Mutations in human lipoyltransferase gene LIPT1 cause a Leigh disease with secondary deficiency for pyruvate and alpha-ketoglutarate dehydrogenase

    PubMed Central

    2013-01-01

    Background Synthesis and apoenzyme attachment of lipoic acid have emerged as a new complex metabolic pathway. Mutations in several genes involved in the lipoic acid de novo pathway have recently been described (i.e., LIAS, NFU1, BOLA3, IBA57), but no mutation was found so far in genes involved in the specific process of attachment of lipoic acid to apoenzymes pyruvate dehydrogenase (PDHc), α-ketoglutarate dehydrogenase (α-KGDHc) and branched chain α-keto acid dehydrogenase (BCKDHc) complexes. Methods Exome capture was performed in a boy who developed Leigh disease following a gastroenteritis and had combined PDH and α-KGDH deficiency with a unique amino acid profile that partly ressembled E3 subunit (dihydrolipoamide dehydrogenase / DLD) deficiency. Functional studies on patient fibroblasts were performed. Lipoic acid administration was tested on the LIPT1 ortholog lip3 deletion strain yeast and on patient fibroblasts. Results Exome sequencing identified two heterozygous mutations (c.875C > G and c.535A > G) in the LIPT1 gene that encodes a mitochondrial lipoyltransferase which is thought to catalyze the attachment of lipoic acid on PDHc, α-KGDHc, and BCKDHc. Anti-lipoic acid antibodies revealed absent expression of PDH E2, BCKDH E2 and α-KGDH E2 subunits. Accordingly, the production of 14CO2 by patient fibroblasts after incubation with 14Cglucose, 14Cbutyrate or 14C3OHbutyrate was very low compared to controls. cDNA transfection experiments on patient fibroblasts rescued PDH and α-KGDH activities and normalized the levels of pyruvate and 3OHbutyrate in cell supernatants. The yeast lip3 deletion strain showed improved growth on ethanol medium after lipoic acid supplementation and incubation of the patient fibroblasts with lipoic acid decreased lactate level in cell supernatants. Conclusion We report here a putative case of impaired free or H protein-derived lipoic acid attachment due to LIPT1 mutations as a cause of PDH and α-KGDH deficiencies. Our

  15. Mutations in human lipoyltransferase gene LIPT1 cause a Leigh disease with secondary deficiency for pyruvate and alpha-ketoglutarate dehydrogenase.

    PubMed

    Soreze, Yohan; Boutron, Audrey; Habarou, Florence; Barnerias, Christine; Nonnenmacher, Luc; Delpech, Hélène; Mamoune, Asmaa; Chrétien, Dominique; Hubert, Laurence; Bole-Feysot, Christine; Nitschke, Patrick; Correia, Isabelle; Sardet, Claude; Boddaert, Nathalie; Hamel, Yamina; Delahodde, Agnès; Ottolenghi, Chris; de Lonlay, Pascale

    2013-12-17

    Synthesis and apoenzyme attachment of lipoic acid have emerged as a new complex metabolic pathway. Mutations in several genes involved in the lipoic acid de novo pathway have recently been described (i.e., LIAS, NFU1, BOLA3, IBA57), but no mutation was found so far in genes involved in the specific process of attachment of lipoic acid to apoenzymes pyruvate dehydrogenase (PDHc), α-ketoglutarate dehydrogenase (α-KGDHc) and branched chain α-keto acid dehydrogenase (BCKDHc) complexes. Exome capture was performed in a boy who developed Leigh disease following a gastroenteritis and had combined PDH and α-KGDH deficiency with a unique amino acid profile that partly ressembled E3 subunit (dihydrolipoamide dehydrogenase / DLD) deficiency. Functional studies on patient fibroblasts were performed. Lipoic acid administration was tested on the LIPT1 ortholog lip3 deletion strain yeast and on patient fibroblasts. Exome sequencing identified two heterozygous mutations (c.875C > G and c.535A > G) in the LIPT1 gene that encodes a mitochondrial lipoyltransferase which is thought to catalyze the attachment of lipoic acid on PDHc, α-KGDHc, and BCKDHc. Anti-lipoic acid antibodies revealed absent expression of PDH E2, BCKDH E2 and α-KGDH E2 subunits. Accordingly, the production of 14CO2 by patient fibroblasts after incubation with 14Cglucose, 14Cbutyrate or 14C3OHbutyrate was very low compared to controls. cDNA transfection experiments on patient fibroblasts rescued PDH and α-KGDH activities and normalized the levels of pyruvate and 3OHbutyrate in cell supernatants. The yeast lip3 deletion strain showed improved growth on ethanol medium after lipoic acid supplementation and incubation of the patient fibroblasts with lipoic acid decreased lactate level in cell supernatants. We report here a putative case of impaired free or H protein-derived lipoic acid attachment due to LIPT1 mutations as a cause of PDH and α-KGDH deficiencies. Our study calls for renewed efforts to

  16. Cerebrospinal fluid lactate and pyruvate concentrations and their ratio.

    PubMed

    Zhang, Wan-Ming; Natowicz, Marvin R

    2013-05-01

    Determinations of cerebrospinal fluid (CSF) lactate and pyruvate concentrations and CSF lactate:pyruvate (L/P) ratios are important in several clinical settings, yet published normative data have significant limitations. We sought to determine a large dataset of stringently-defined normative data for CSF lactate and pyruvate concentrations and CSF L/P ratios. We evaluated data from 627 patients who had determinations of CSF lactate and/or CSF pyruvate from 2001 to 2011 at the Cleveland Clinic. Inclusion in the normal reference population required normal CSF cell counts, glucose and protein and routine serum chemistries and absence of progressive brain disorder, epilepsy, or seizure within 24h. Brain MRI, if done, showed no evidence of tumor, acute changes or basal ganglia abnormality. CSF cytology, CSF alanine and immunoglobulin levels, and oligoclonal band analysis were required to be normal, if done. Various inclusion/exclusion criteria were compared. 92 patients fulfilled inclusion/exclusion criteria for a reference population. The 95% central intervals (2.5%-97.5%) for CSF lactate and pyruvate levels were 1.01-2.09mM and 0.03-0.15mM, respectively, and 9.05-26.37 for CSF L/P. There were no significant gender-related differences of CSF lactate or pyruvate concentrations or of CSF L/P. Weak positive correlations between the concentration of CSF lactate or pyruvate and age were noted. Using stringent inclusion/exclusion criteria, we determined normative data for CSF lactate and pyruvate concentrations and CSF L/P ratios in a large, well-characterized reference population. Normalcy of routine CSF and blood analytes are the most important parameters in determining reference intervals for CSF lactate and pyruvate. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Association of brain metabolites with blood lactate and glucose levels with respect to neurological outcomes after out-of-hospital cardiac arrest: A preliminary microdialysis study.

    PubMed

    Hifumi, Toru; Kawakita, Kenya; Yoda, Takeshi; Okazaki, Tomoya; Kuroda, Yasuhiro

    2017-01-01

    Out-of-hospital cardiac arrest (OHCA) is associated with poor prognosis. Cerebral microdialysis (CMD) is an efficient sampling technique to detect neurochemical changes in brain interstitial tissue. In this retrospective study, we hypothesised that there are different CMD levels between patients with favourable and unfavourable neurological outcomes. Data of patients with OHCA admitted to Kagawa University Hospital and administered therapeutic hypothermia (TH) were collected. Using a CMD probe, extracellular glucose, lactate and pyruvate levels were measured hourly along with intracranial perfusion pressure (ICP) and cerebral perfusion pressure (CPP) for the initial 72h during TH. The lactate/pyruvate (LP) ratio was calculated. Patients were divided into favourable [Glasgow-Pittsburgh cerebral performance category 1-2 at 30days after cardiac arrest] or unfavourable neurological outcome groups. CMD biochemical markers and blood lactate and glucose levels were compared between two groups. Ten patients were included. ICP was significantly higher in the unfavourable than in the favourable neurological outcome group; there were no significant differences with respect to CPP. The CMD LP ratio in the unfavourable outcome group progressively increased; significant differences were observed on days 2, 3 and 4 (p<0.01). Significant differences in blood lactate levels were observed between the groups only on day 3.5. CMD and blood glucose levels were higher in the unfavourable than in the favourable outcome group during TH. The association of CMD levels with long-term outcomes would be better defined in a large randomised prospective study. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Identification of a dehydrogenase acting on D-2-hydroxyglutarate

    PubMed Central

    2004-01-01

    Extracts of frozen rat liver were found to catalyse the formation of 3H2O from DL-2-hydroxy[2-3H]glutarate. Three peaks of enzyme activities were observed on separation by chromatography on DEAE-Sepharose. The first and second peaks corresponded to an enzyme acting on L-2-hydroxyglutarate and the third peak corresponded to an enzyme acting on D-2-hydroxyglutarate, as indicated by competitive inhibition of the detritiation of the racemic radioactive compound by the unlabelled L- and D-isomers respectively. The enzyme acting on the D-form was further characterized. It was independent of NAD or NADP and it converted D-2-hydroxyglutarate into α-ketoglutarate, transferring electrons to artificial electron acceptors. It also oxidized D-lactate, D-malate and meso-tartrate and was stimulated by Zn2+, Co2+ and Mn2+, but not by Mg2+ or Ca2+. Subcellular fractionation indicated that it was present in the mitochondrial fraction. The enzyme was further purified by chromatography on Blue Trisacryl and phenyl-Sepharose, up to a stage where only a few bands were still visible by SDS/ PAGE. Among the four candidate polypeptides that were identified by MS, one corresponded to a predicted mitochondrial protein homologous with FAD-dependent D-lactate dehydrogenase. The corresponding human protein was expressed in HEK-293 cells and it was shown to catalyse the detritiation of DL-2-hydroxy[2-3H]glutarate with similar properties as the purified rat enzyme. PMID:15070399

  19. Identification of a dehydrogenase acting on D-2-hydroxyglutarate.

    PubMed

    Achouri, Younes; Noël, Gaëtane; Vertommen, Didier; Rider, Mark H; Veiga-Da-Cunha, Maria; Van Schaftingen, Emile

    2004-07-01

    Extracts of frozen rat liver were found to catalyse the formation of 3H2O from DL-2-hydroxy[2-3H]glutarate. Three peaks of enzyme activities were observed on separation by chromatography on DEAE-Sepharose. The first and second peaks corresponded to an enzyme acting on L-2-hydroxyglutarate and the third peak corresponded to an enzyme acting on D-2-hydroxyglutarate, as indicated by competitive inhibition of the detritiation of the racemic radioactive compound by the unlabelled L- and D-isomers respectively. The enzyme acting on the D-form was further characterized. It was independent of NAD or NADP and it converted D-2-hydroxyglutarate into a-ketoglutarate, transferring electrons to artificial electron acceptors. It also oxidized D-lactate, D-malate and meso-tartrate and was stimulated by Zn2+, Co2+ and Mn2+, but not by Mg2+ or Ca2+. Subcellular fractionation indicated that it was present in the mitochondrial fraction. The enzyme was further purified by chromatography on Blue Trisacryl and phenyl-Sepharose, up to a stage where only a few bands were still visible by SDS/PAGE. Among the four candidate polypeptides that were identified by MS, one corresponded to a predicted mitochondrial protein homologous with FAD-dependent D-lactate dehydrogenase. The corresponding human protein was expressed in HEK-293 cells and it was shown to catalyse the detritiation of DL-2-hydroxy[2-3H]glutarate with similar properties as the purified rat enzyme.

  20. Efficiency of food utilization by pregnant and lactating sows. 2. The influence of isocaloric diets with different protein levels on pregnancy and lactation.

    PubMed

    Burlacu, G; Iliescu, M; Cărămidă, P

    1986-09-01

    The efficiency of utilization of feed energy as digestible, metabolizable and net energy is similar in pregnant and lactating sows irrespective of the stage of these physiological conditions. This efficiency with the value of about 71% resembles the one found in the growing and fattening pigs, which enables us to use, for this category of animals, the same system offered evaluation and of the energy requirements based on fat nutritive units. The maintenance energy requirement expressed in ME varies from 467 kJ/kg 0.75 in pregnant sows to 512 kJ/kg 0.75 in lactating sows, for the suckling piglets having intermediary value of 498 kJ/kg 0.75. The efficiency of utilization of diets protein for maintenance and for synthesis is also similar for these categories of pigs, varying from 71% in lactating sows to 75-76% in pregnant sows. In suckling piglets we had recorded an efficiency of DCP utilization which varies parabolically with size of the ingesta and therefore with that of weight gain. The DCP maintenance requirement expressed in g N dig./kg 0.75 varies within narrow limits between 0.345 g N in suckling piglets 0.380 g N in pregnant sows; In lactating sows we have detected an intermediary value of 0.355 g N. Based on these experimental data and also using recent experimental results obtained by Schiemann and Beyer (1984) regarding the energy and N content of the foetuses, of the organs of reproductions and of milk, we could calculate the energy and protein requirements. These requirements when compared with the values used in our country show us higher values of energy in pregnant and lactating sows and lower values of protein for the same categories, including the piglets, where we have also found lower values for the energy too.

  1. Novel homologous lactate transporter improves L-lactic acid production from glycerol in recombinant strains of Pichia pastoris.

    PubMed

    de Lima, Pollyne Borborema Almeida; Mulder, Kelly Cristina Leite; Melo, Nadiele Tamires Moreira; Carvalho, Lucas Silva; Menino, Gisele Soares; Mulinari, Eduardo; de Castro, Virgilio H; Dos Reis, Thaila F; Goldman, Gustavo Henrique; Magalhães, Beatriz Simas; Parachin, Nádia Skorupa

    2016-09-15

    Crude glycerol is the main byproduct of the biodiesel industry. Although it can have different applications, its purification is costly. Therefore, in this study a biotechnological route has been proposed for further utilization of crude glycerol in the fermentative production of lactic acid. This acid is largely utilized in food, pharmaceutical, textile, and chemical industries, making it the hydroxycarboxylic acid with the highest market potential worldwide. Currently, industrial production of lactic acid is done mainly using sugar as the substrate. Thus here, for the first time, Pichia pastoris has been engineered for heterologous L-lactic acid production using glycerol as a single carbon source. For that, the Bos taurus lactate dehydrogenase gene was introduced into P. pastoris. Moreover, a heterologous and a novel homologous lactate transporter have been evaluated for L-lactic acid production. Batch fermentation of the P. pastoris X-33 strain producing LDHb allowed for lactic acid production in this yeast. Although P. pastoris is known for its respiratory metabolism, batch fermentations were performed with different oxygenation levels, indicating that lower oxygen availability increased lactic acid production by 20 %, pushing the yeast towards a fermentative metabolism. Furthermore, a newly putative lactate transporter from P. pastoris named PAS has been identified by search similarity with the lactate transporter from Saccharomyces cerevisiae Jen1p. Both heterologous and homologous transporters, Jen1p and PAS, were evaluated in one strain already containing LDH activity. Fed-batch experiments of P. pastoris strains carrying the lactate transporter were performed with the batch phase at aerobic conditions followed by an aerobic oxygen-limited phase where production of lactic acid was favored. The results showed that the strain containing PAS presented the highest lactic acid titer, reaching a yield of approximately 0.7 g/g. We showed that P. pastoris has a

  2. Channel-mediated lactate release by K⁺-stimulated astrocytes.

    PubMed

    Sotelo-Hitschfeld, Tamara; Niemeyer, María I; Mächler, Philipp; Ruminot, Iván; Lerchundi, Rodrigo; Wyss, Matthias T; Stobart, Jillian; Fernández-Moncada, Ignacio; Valdebenito, Rocío; Garrido-Gerter, Pamela; Contreras-Baeza, Yasna; Schneider, Bernard L; Aebischer, Patrick; Lengacher, Sylvain; San Martín, Alejandro; Le Douce, Juliette; Bonvento, Gilles; Magistretti, Pierre J; Sepúlveda, Francisco V; Weber, Bruno; Barros, L Felipe

    2015-03-11

    Excitatory synaptic transmission is accompanied by a local surge in interstitial lactate that occurs despite adequate oxygen availability, a puzzling phenomenon termed aerobic glycolysis. In addition to its role as an energy substrate, recent studies have shown that lactate modulates neuronal excitability acting through various targets, including NMDA receptors and G-protein-coupled receptors specific for lactate, but little is known about the cellular and molecular mechanisms responsible for the increase in interstitial lactate. Using a panel of genetically encoded fluorescence nanosensors for energy metabolites, we show here that mouse astrocytes in culture, in cortical slices, and in vivo maintain a steady-state reservoir of lactate. The reservoir was released to the extracellular space immediately after exposure of astrocytes to a physiological rise in extracellular K(+) or cell depolarization. Cell-attached patch-clamp analysis of cultured astrocytes revealed a 37 pS lactate-permeable ion channel activated by cell depolarization. The channel was modulated by lactate itself, resulting in a positive feedback loop for lactate release. A rapid fall in intracellular lactate levels was also observed in cortical astrocytes of anesthetized mice in response to local field stimulation. The existence of an astrocytic lactate reservoir and its quick mobilization via an ion channel in response to a neuronal cue provides fresh support to lactate roles in neuronal fueling and in gliotransmission. Copyright © 2015 the authors 0270-6474/15/354168-11$15.00/0.

  3. Directed modification of L-LcLDH1, an L-lactate dehydrogenase from Lactobacillus casei, to improve its specific activity and catalytic efficiency towards phenylpyruvic acid.

    PubMed

    Li, Jian-Fang; Li, Xue-Qing; Liu, Yan; Yuan, Feng-Jiao; Zhang, Ting; Wu, Min-Chen; Zhang, Ji-Ru

    2018-05-22

    To improve the specific activity and catalytic efficiency of L-LcLDH1, an NADH-dependent allosteric L-lactate dehydrogenase from L. casei, towards phenylpyruvic acid (PPA), its directed modification was conducted based on the semi-rational design. The three variant genes, Lcldh1 Q88R , Lcldh1 I229A and Lcldh1 T235G , were constructed by whole-plasmid PCR as designed theoretically, and expressed in E. coli BL21(DE3), respectively. The purified mutant, L-LcLDH1 Q88R or L-LcLDH1 I229A , displayed the specific activity of 451.5 or 512.4 U/mg towards PPA, by which the asymmetric reduction of PPA afforded L-phenyllactic acid (PLA) with an enantiomeric excess (ee p ) more than 99%. Their catalytic efficiencies (k cat /K m ) without D-fructose-1,6-diphosphate (D-FDP) were 4.8- and 5.2-fold that of L-LcLDH1. Additionally, the k cat /K m values of L-LcLDH1 Q88R and L-LcLDH1 I229A with D-FDP were 168.4- and 8.5-fold higher than those of the same enzymes without D-FDP, respectively. The analysis of catalytic mechanisms by molecular docking (MD) simulation indicated that substituting I229 in L-LcLDH1 with Ala enlarges the space of substrate-binding pocket, and that the replacement of Q88 with Arg makes the inlet of pocket larger than that of L-LcLDH1. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. 1H-NMR and Hyperpolarized 13C-NMR Assays of Pyruvate-Lactate Exhange: a comparative study

    PubMed Central

    Orton, Matthew R.; Tardif, Nicolas; Parkes, Harold G.; Robinson, Simon P.; Leach, Martin O.; Chung, Yuen-Li; Eykyn, Thomas R.

    2015-01-01

    Pyruvate-lactate exchange is mediated by the enzyme lactate dehydrogenase (LDH) and is central to the altered energy metabolism in cancer cells. Measurement of exchange kinetics using hyperpolarized 13C NMR has provided a biomarker of response to novel therapeutics. In this study we investigated an alternative in vitro 1H assay, using [3-13C]pyruvate, and compared the measured kinetics with a hyperpolarized 13C-NMR assay, using [1-13C]pyruvate, under the same conditions in human colorectal carcinoma SW1222 cells. The apparent forward reaction rate constants (kPL) derived from the two assays showed no significant difference, and both assays had similar reproducibility (kPL = 0.506 ± 0.054 and kPL = 0.441 ± 0.090 nmol/s/106 cells, (mean ± standard deviation, n = 3); 1H, 13C assays respectively). The apparent backward reaction rate constant (kLP) could only be measured with good reproducibility using the 1H-NMR assay (kLP = 0.376 ± 0.091 nmol/s/106 cells, (mean ± standard deviation, n = 3)). The 1H-NMR assay has adequate sensitivity to measure real-time pyruvate-lactate exchange kinetics in vitro, offering a complementary and accessible assay of apparent LDH activity. PMID:23712817

  5. Lactation curves of dairy camels in an intensive system.

    PubMed

    Musaad, Abdelgadir; Faye, Bernard; Nikhela, Abdelmoneim Abu

    2013-04-01

    Weekly milk records of 47 she-camels in a multibreed dairy camel herd were collected for over a period of 5 years. A total of 72 lactation curves were defined, and relationships with parity, calving season, lactation length, milk production level, following lactations, and dam weight were analyzed. Overall mean values were milk yield up to 12 months, 1,970 ± 790 l; lactation length, 12.5 months; persistency, 94.7 %; weekly peak yield, 50.7 l; monthly peak yield, 220 ± 90 l; and the number of weeks to reach peak yield, 28. The highest productivity was recorded in summer with a weekly mean of 48.2 ± 19.4 l, compared with 34.1 ± 16.3 l in winter. The highest average yield recorded was for camels at sixth parity, whereas the highest weekly peak was at eighth parity, and highest persistency at fifth parity. Camels that calved during the cold months (November to February) were most productives, with the highest persistency, peak yield, and longest lactation length. Four types of curves were identified corresponding to different parities and milk yield levels. Based on these data, specific models for camels are proposed.

  6. Characterization of human short chain dehydrogenase/reductase SDR16C family members related to retinol dehydrogenase 10.

    PubMed

    Adams, Mark K; Lee, Seung-Ah; Belyaeva, Olga V; Wu, Lizhi; Kedishvili, Natalia Y

    2017-10-01

    All-trans-retinoic acid (RA) is a bioactive derivative of vitamin A that serves as an activating ligand for nuclear transcription factors, retinoic acid receptors. RA biosynthesis is initiated by the enzymes that oxidize retinol to retinaldehyde. It is well established that retinol dehydrogenase 10 (RDH10, SDR16C4), which belongs to the 16C family of the short chain dehydrogenase/reductase (SDR) superfamily of proteins, is the major enzyme responsible for the oxidation of retinol to retinaldehyde for RA biosynthesis during embryogenesis. However, several lines of evidence point towards the existence of additional retinol dehydrogenases that contribute to RA biosynthesis in vivo. In close proximity to RDH10 gene on human chromosome 8 are located two genes that are phylogenetically related to RDH10. The predicted protein products of these genes, retinol dehydrogenase epidermal 2 (RDHE2, SDR16C5) and retinol dehydrogenase epidermal 2-similar (RDHE2S, SDR16C6), share 59% and 56% sequence similarity with RDH10, respectively. Previously, we showed that the single ortholog of the human RDHE2 and RDHE2S in frogs, Xenopus laevis rdhe2, oxidizes retinol to retinaldehyde and is essential for frog embryonic development. In this study, we explored the potential of each of the two human proteins to contribute to RA biosynthesis. The results of this study demonstrate that human RDHE2 exhibits a relatively low but reproducible activity when expressed in either HepG2 or HEK293 cells. Expression of the native RDHE2 is downregulated in the presence of elevated levels of RA. On the other hand, the protein encoded by the human RDHE2S gene is unstable when expressed in HEK293 cells. RDHE2S protein produced in Sf9 cells is stable but has no detectable catalytic activity towards retinol. We conclude that the human RDHE2S does not contribute to RA biosynthesis, whereas the low-activity RA-sensitive human RDHE2 may have a role in adjusting the cellular levels of RA in accord with

  7. A temporary local energy pool coupled to neuronal activity: fluctuations of extracellular lactate levels in rat brain monitored with rapid-response enzyme-based sensor.

    PubMed

    Hu, Y; Wilson, G S

    1997-10-01

    A successfully developed enzyme-based lactate microsensor with rapid response time allows the direct and continuous in vivo measurement of lactic acid concentration with high temporal resolution in brain extracellular fluid. The fluctuations coupled to neuronal activity in extracellular lactate concentration were explored in the dentate gyrus of the hippocampus of the rat brain after electrical stimulation of the perforant pathway. Extracellular glucose and oxygen levels were also detected simultaneously by coimplantation of a fast-response glucose sensor and an oxygen electrode, to provide novel information of trafficking of energy substances in real time related to local neuronal activity. The results first give a comprehensive picture of complementary energy supply and use of lactate and glucose in the intact brain tissue. In response to acute neuronal activation, the brain tissue shifts immediately to significant energy supply by lactate. A local temporary fuel "reservoir" is established behind the blood-brain barrier, evidenced by increased extracellular lactate concentration. The pool can be depleted rapidly, up to 28% in 10-12 s, by massive, acute neuronal use after stimulation and can be replenished in approximately 20 s. Glutamate-stimulated astrocytic glycolysis and the increase of regional blood flow may regulate the lactate concentration of the pool in different time scales to maintain local energy homeostasis.

  8. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps ...

  9. Raised serum lactate: a marker of necrotizing fasciitis?

    PubMed

    Murphy, George; Markeson, Daniel; Choa, Robert; Armstrong, Anthony

    2013-12-01

    Distinguishing necrotizing fasciitis from non-necrotizing soft-tissue infections remains a difficult clinical judgement call, with a paucity of diagnostic aids to the clinician. The aim of this study was to assess raised serum lactate as a point-of-care test to aid in differentiating necrotizing from non-necrotizing soft tissue infections. The authors performed a post-hoc analysis of a prospectively compiled database. All patients referred to a single surgeon (A.P.A.) as suspected cases of necrotizing fasciitis at one hospital between September 2000 and September 2010 were included. Serum lactate at presentation was recorded, along with demographic and outcome data. Using histological evidence of tissue necrosis as the 'gold standard', patients were divided into those with or without necrotizing fasciitis, and their serum lactate at presentation compared. Fifty three patients met the inclusion criteria. Twenty eight had histologically proven necrosis, 25 did not. Serum lactate (mean±SD) was 4.1±1.62 mmol/l in the necrotizing fasciitis group and 1.8±0.46 mmol/l in the non-necrotizing fasciitis group (p≤0.0001). A serum lactate level above 2.0 mmol/l had a sensitivity of 1.00 and a specificity of 0.76 for necrotizing fasciitis in this series. In this series of patients with suspected necrotizing soft tissue infection, serum lactate levels above 2.0 mmol/l at presentation were strongly associated with the presence of tissue necrosis. Although no test can be relied upon in isolation, our results suggest that serum lactate is a promising adjunct to the diagnosis of necrotizing infection, which could help to expedite appropriate management. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. Fabrication of Flexible Arrayed Lactate Biosensor Based on Immobilizing LDH-NAD+ on NiO Film Modified by GO and MBs

    PubMed Central

    Yan, Siao-Jie; Liao, Yi-Hung; Lai, Chih-Hsien; Wu, You-Xiang; Wu, Cian-Yi; Chen, Hsiang-Yi; Huang, Hong-Yu; Wu, Tong-Yu

    2017-01-01

    We proposed the flexible arrayed lactate biosensor based on immobilizing l-lactate dehydrogenase (LDH) and nicotinamide adenine dinucleotide (NAD+) on nickel oxide (NiO) film, and which the average sensitivity could be enhanced by using graphene oxide (GO) and magnetic beads (MBs). By using GO and MBs, it exhibits excellent sensitivity (45.397 mV/mM) with a linearity of 0.992 in a range of 0.2 mM to 3 mM. According to the results of electrochemical impedance spectroscopy (EIS), the electron transfer resistance of LDH-NAD+-MBs/GPTS/GO/NiO film was smaller than those of LDH-NAD+/GPTS/GO/NiO film and LDH-NAD+/GPTS/NiO film, and it presented the outstanding electron transfer ability. After that, the limit of detection, anti-interference effect and bending test were also investigated. PMID:28704960

  11. Caffeine poisoning and lactate rise: an overlooked toxic effect?

    PubMed

    Schmidt, A; Karlson-Stiber, C

    2008-08-01

    Severe caffeine poisoning is rare but associated with a high mortality. The symptoms are mainly attributable to hyperadrenergic stimulation, are relatively well known and described in the literature. Transient rises in plasma lactate levels may occur but are, however, less well described. We present a case of serious caffeine poisoning with a concomitant rise in lactate treated with a non-selective beta-blocker and discuss briefly the symptomatology, the management of caffeine poisoning and the association between lactate and metabolic acidosis.

  12. Effects of nutrition on pregnant and lactating sows.

    PubMed

    Einarsson, S; Rojkittikhun, T

    1993-01-01

    It has been suggested that the long-term reproduction of the sow is best served by minimizing weight and fat loss in lactation. Such a strategy would require only a minimal restoration of weight in the following pregnancy, which would be beneficial, since the greater feed intake and weight gain in pregnancy, the greater the weight loss in lactation. Feeding ad libitum should be practised during lactation while gestation feed intake must be held low. A relationship between feed intake and embryo survival has been demonstrated in several studies, but the data are sometimes difficult to interpret. High energy feeding during the premating period and during early pregnancy, however, are often associated with increased embryo mortality. A short-term starvation in lactation decreased prolactin to post-weaning concentrations, and insulin and glucose to very low concentrations. Prolactin increased very rapidly after refeeding indicating that a neural mechanism might be involved. The increasing levels of cholecystokinin after refeeding and the neural reflex triggered might be related to this increase in prolactin. No changes in LH release were observed during the periods of starvation or refeeding. The catabolic rate during the first week of lactation is higher in sows with higher backfat thickness than in late gestation. As lactation progresses a more balanced metabolism is achieved regardless of backfat thickness before parturition. High-weight-loss primiparous sows need a longer recovery period from their negative energy balance during lactation than do low-weight-loss primiparous sows or multiparous sows. Several investigations have demonstrated that sows losing excessive amounts of body weight have extended weaning to oestrous intervals and an increase in anoestrus. Sows with low body-weight loss during lactation have higher plasma insulin and lower cortisol around weaning than do sows with high body-weight loss. What remains undefined is the degree of weight or

  13. Effect of HX108-CS supplementation on exercise capacity and lactate accumulation after high-intensity exercise.

    PubMed

    Oh, Seung-Lyul; Chang, Hyukki; Kim, Hee-Jae; Kim, Yong-An; Kim, Dong-Sik; Ho, Seong-Hyun; Kim, Seon-Hee; Song, Wook

    2013-04-15

    In the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro. Exercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague-Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity. Blood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner. These results suggest that supplementation with HX

  14. Effect of HX108-CS supplementation on exercise capacity and lactate accumulation after high-intensity exercise

    PubMed Central

    2013-01-01

    Background In the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro. Methods Exercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague–Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity. Results Blood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner. Conclusions These

  15. myo-Inositol metabolism during lactation and development in the rat. The prevention of lactation-induced fatty liver by dietary myo-inositol.

    PubMed

    Burton, L E; Wells, W W

    1976-11-01

    Effects of dietary myo-inositol deprivation were examined during prenatal and postnatal development and during lactation in the rat. The deficient diet contained no detectable myo-inositol while the supplemented diet contained 0.5% (w/w) myo-inositol while the supplemented diet ct contained 0.5% (w/w) myo-inositol at the expense of sucrose. Both diets contained 25% casein, adequate amounts of all known vitamins, choline, and essential fatty acids as well as 0.5% (w/w) phthalylsulfathiazole to depress myo-inositol contribution to the diet by microorganisms. Pregnant rats of the Holtzman strain were fed the respective diets during gestation and lactation, and pups were fed the corresponding diet after weaning until 3 months of age. There were no significant differen-es in body weight between experimental groups. Supplementation of the diet with myo-inositol significanly increased the levels of myo-inositol in plasma, liver, kidney, and intestine of pups at all ages examined, and significantly increased the levels of myo-inositol in the milk and mammary tissue during lactation. During lactation, the myo-inositol deprived dams developed severe fatty livers (31% w/w) characterized by diminished phosphatidyl-inositol (50%) and total phospholipid phosphorus (57%) levels as compared with controls. After weaning, the liver lipid content of the myo-inositol deprived dams returned to normal (4.5%). The data suggest that a possible threshold level of free myo-inositol (approximately 0.15 mumoles/g lipid-free tissue) was required to prevent fatty liver in lactating dams under these dietary conditions. Effects of the deficient diet on fertility were also examined. Based on sperm count and production of offspring, there were no differnences between the experimental and control males. Females of both groups showed equal ability to produce offspring.

  16. Association between Several Persistent Organic Pollutants in Serum and Adipokine Levels in Breast Milk among Lactating Women of Korea.

    PubMed

    Kim, Sunmi; Park, Jeongim; Kim, Hai-Joong; Lee, Jeong Jae; Choi, Gyuyeon; Choi, Sooran; Kim, Sungjoo; Kim, Su Young; Lee, Duk Hee; Moon, Hyo-Bang; Kim, Sungkyoon; Choi, Kyungho

    2015-07-07

    Exposure to several persistent organic pollutants (POPs) has been linked to alteration of lipid metabolism. Adipokines, such as leptin and adiponectin, are hormones that play roles in lipid metabolism, and have been suggested as markers of health effects that may lead to obesity. To date, only serum adipokines have been associated with POPs exposure. In the present study, for the first time, the associations between leptin and adiponectin in breast milk, and several POPs in serum were investigated among 82 lactating Korean women between 25 and 46 years of age. Breast milk adipokines are important because adipokine intake of infant through breastfeeding may influence the growth of infants. The median concentrations of leptin and adiponectin in skimmed milk of the Korean lactating women were 17.9 ng/L and 16.5 μg/L, respectively. Leptin concentrations in breast milk were negatively associated with ∑hexachlorohexane (HCH), oxychlordane, ∑chlordane, or 2,2',4,4',5,5'-hexachlorobiphenyl (CB 153) levels in maternal serum. Linear relationships between adiponectin and POPs concentrations were not observed, however, nonmonotonic relationship which showed generally positive associations was suggested for p,p'-dichlorodiphenyltrichloroethane (DDT) and ∑chlordane in quartile analysis. Our observations show that POPs at the current level of exposure may be associated with the alteration of lipid metabolism among lactating women. Implication of adipokine transfer to breastfed infants is of concern and deserves further investigation.

  17. Development of an enzymatic assay to measure lactate in perchloric acid-precipitated cerebrospinal fluid.

    PubMed

    Lu, Jun; Genzen, Jonathan R; Grenache, David G

    2018-04-27

    Individuals with inherited deficiencies of the pyruvate dehydrogenase complex or the respiratory chain complex can have increased concentrations of cerebrospinal fluid (CSF) lactate. Such measurements are clinical useful when measured in conjunction with pyruvate in order to calculate the lactate:pyruvate (L:P) ratio, a useful surrogate of cytosolic redox status. CSF pyruvate is measured in a protein-free supernatant prepared by the addition of CSF to perchloric acid while lactate is measured in untreated CSF. Utilizing the same sample for both lactate and pyruvate measurements is desirable. To develop a method to measure lactate in perchloric-acid precipitated CSF and validate the L:P ratio as calculated from the analysis of both analytes in the same sample. Samples were prepared by the addition of 1 mL CSF to 2 mL 8% (w/v) cold perchloric acid, incubated on ice for 10 min, then centrifuged to obtain a protein-free supernatant. Lactate was measured by its oxidation to pyruvate and hydrogen peroxide using lactate oxidase and the absorbance of the resulting chromogen determined at 540 nm on a Roche cobas c501 chemistry analyzer. Method accuracy, linearity, imprecision and sensitivity were determined and a reference interval was verified. To assess accuracy, this method was compared to lactate determined in unaltered CSF at another laboratory using 41 specimens with lactate concentrations from 0.6-11.9 mmol/L. Linear regression produced a slope of 1.09 and y-intercept of 0.26 (R 2  = 1.00). Recovery was performed by ad-mixes of a high lactate standard and a CSF pool in different ratios to create a set of 19 samples prior to preparing protein-free supernatants. Recovery was 94.6-100% (mean ± SD was 97.4 ± 1.4%) at lactate concentrations of 2.68 to 12.63 mmol/L. Linearity was determined by combining two supernatants with low and high lactate concentrations in different ratios to create a set of six samples (0.15-12.70 mmol/L) that were

  18. Maternal Exposure to Ethanol During Pregnancy and Lactation Affects Glutamatergic System and Induces Oxidative Stress in Offspring Hippocampus.

    PubMed

    Cesconetto, Patricia A; Andrade, Camila M; Cattani, Daiane; Domingues, Juliana T; Parisotto, Eduardo B; Filho, Danilo W; Zamoner, Ariane

    2016-01-01

    Alcohol abuse during pregnancy leads to intellectual disability and morphological defects in the offspring. The aim of this study was to determine the effect of chronic maternal ethanol (EtOH) consumption during pregnancy and lactation on glutamatergic transmission regulation, energy deficit, and oxidative stress in the hippocampus of the offspring. EtOH was administered to dams in drinking water at increasing doses (2 to 20%) from the gestation day 5 to lactation day 21. EtOH and tap water intake by treated and control groups, respectively, were measured daily. Results showed that EtOH exposure does not affect fluid intake over the course of pregnancy and lactation. The toxicity of maternal exposure to EtOH was demonstrated by decreased offspring body weight at experimental age, on postnatal day 21. Moreover, maternal EtOH exposure decreased (45) Ca(2+) influx in the offspring's hippocampus. Corroborating this finding, EtOH increased both Na(+) -dependent and Na(+) -independent glial [(14) C]-glutamate uptake in hippocampus of immature rats. Also, maternal EtOH exposure decreased glutamine synthetase activity and induced aspartate aminotransferase enzymatic activity, suggesting that in EtOH-exposed offspring hippocampus, glutamate is preferentially used as a fuel in tricarboxylic acid cycle instead of being converted into glutamine. In addition, EtOH exposure decreased [U-14C]-2-deoxy-D-glucose uptake in offspring hippocampus. The decline in glucose transport coincided with increased lactate dehydrogenase activity, suggesting an adaptative response in EtOH-exposed offspring hippocampus, using lactate as an alternative fuel. These events were associated with oxidative damage, as demonstrated by changes in the enzymatic antioxidant defense system and lipid peroxidation. Taken together, the results demonstrate that maternal exposure to EtOH during pregnancy and lactation impairs glutamatergic transmission, as well as inducing oxidative stress and energy deficit in

  19. Hypothalamic neuropeptides, not leptin sensitivity, contributes to the hyperphagia in lactating Brandt's voles, Lasiopodomys brandtii.

    PubMed

    Cui, Jian-Guo; Tang, Gang-Bing; Wang, De-Hua

    2011-07-01

    Both pregnancy and lactation are associated with hyperphagia, and circulating leptin levels are elevated during pregnancy but decreased during lactation in Brandt's voles, Lasiopodomys brandtii. Previous findings suggest that impaired leptin sensitivity contributes to hyperphagia during pregnancy. The present study aimed to examine whether the decreased circulating leptin level and/or hypothalamic leptin sensitivity contributed to the hyperphagia during lactation in Brandt's voles. The serum leptin level and mRNA expression of the long form of the leptin receptor (Ob-Rb), suppressor-of-cytokine-signalling-3 (SOCS-3), neuropeptide Y (NPY), agouti-related protein (AgRP), pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) in the hypothalamus were examined on dioestrous, day 5, day 17 of lactation and day 27 (1 week after weaning) in Brandt's voles. Compared with controls, hypothalamic Ob-Rb and SOCS-3 mRNA expression was not significantly changed during lactation. The serum leptin level was significantly lower in lactating females than in the non-reproductive group. Hypothalamic NPY and AgRP mRNA expression significantly increased whereas POMC mRNA expression was significantly decreased during lactation compared with controls. However, there were no significant changes in hypothalamic CART mRNA expression. Food intake was positively correlated with NPY and AgRP mRNA expression but negatively correlated with POMC mRNA expression during lactation. These data suggest that hyperphagia during lactation was associated with low leptin levels, but not impaired leptin sensitivity, and that the hypothalamic neuropeptides NPY, AgRP and POMC are involved in mediating the role of leptin in food intake regulation in lactating Brandt's voles.

  20. Astrocyte-neuron lactate transport is required for long-term memory formation.

    PubMed

    Suzuki, Akinobu; Stern, Sarah A; Bozdagi, Ozlem; Huntley, George W; Walker, Ruth H; Magistretti, Pierre J; Alberini, Cristina M

    2011-03-04

    We report that, in the rat hippocampus, learning leads to a significant increase in extracellular lactate levels that derive from glycogen, an energy reserve selectively localized in astrocytes. Astrocytic glycogen breakdown and lactate release are essential for long-term but not short-term memory formation, and for the maintenance of long-term potentiation (LTP) of synaptic strength elicited in vivo. Disrupting the expression of the astrocytic lactate transporters monocarboxylate transporter 4 (MCT4) or MCT1 causes amnesia, which, like LTP impairment, is rescued by L-lactate but not equicaloric glucose. Disrupting the expression of the neuronal lactate transporter MCT2 also leads to amnesia that is unaffected by either L-lactate or glucose, suggesting that lactate import into neurons is necessary for long-term memory. Glycogenolysis and astrocytic lactate transporters are also critical for the induction of molecular changes required for memory formation, including the induction of phospho-CREB, Arc, and phospho-cofilin. We conclude that astrocyte-neuron lactate transport is required for long-term memory formation. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Astrocyte-neuron lactate transport is required for long-term memory formation

    PubMed Central

    Suzuki, Akinobu; Stern, Sarah A.; Bozdagi, Ozlem; Huntley, George W.; Walker, Ruth H.; Magistretti, Pierre J.; Alberini, Cristina M.

    2011-01-01

    SUMMARY We report that in the rat hippocampus learning leads to a significant increase in extracellular lactate levels, which derive from glycogen, an energy reserve selectively localized in astrocytes. Astrocytic glycogen breakdown and lactate release are essential for long-term but not short-term memory formation, and for the maintenance of long-term potentiation (LTP) of synaptic strength elicited in-vivo. Disrupting the expression of the astrocytic lactate transporters monocarboxylate transporter 4 (MCT4) or MCT1 causes amnesia, which, like LTP impairment, is rescued by lactate but not equicaloric glucose. Disrupting the expression of the neuronal lactate transporter MCT2 also leads to amnesia that is unaffected by either L-lactate or glucose, suggesting that lactate import into neurons is necessary for long-term memory. Glycogenolysis and astrocytic lactate transporters are also critical for the induction of molecular changes required for memory formation, including the induction of phospho-CREB, Arc and phospho-cofilin. We conclude that astrocyte-neuron lactate transport is required for long-term memory formation. PMID:21376239

  2. The effect of lactational mastitis on the macronutrient content of breast milk.

    PubMed

    Say, Birgul; Dizdar, Evrim Alyamaç; Degirmencioglu, Halil; Uras, Nurdan; Sari, Fatma Nur; Oguz, Suna; Canpolat, Fuat Emre

    2016-07-01

    Mastitis in lactating mothers reduces milk production and alters the cellular composition of milk. Changes occurring in the mammary gland during the inflammatory response are believed to increase the permeability of the blood-milk barrier. This study examined the effect of mastitis during lactation on the macronutrient content of breast milk. The study was conducted at Zekai Tahir Burak Maternity Teaching Hospital. Transitional breast milk samples were obtained from term lactating mothers with or without mastitis. Milk protein, fat, carbohydrate, and energy levels were measured using a mid-infrared human milk analyzer. The study recruited 30 term lactating mothers: 15 mothers diagnosed with mastitis and 15 healthy mothers. The characteristics of the mothers in both groups were similar. Fat, carbohydrate, and energy levels were statistically lower in the milk samples of mothers with mastitis compared with the mothers without mastitis. Lactational mastitis was associated with lower breast milk fat, carbohydrate, and energy levels. The local inflammatory response induced by cytokines and increased blood-milk barrier permeability might account for the changes in the fat, carbohydrate, and energy levels of human milk. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci.

    PubMed

    Pavlova, Sylvia I; Jin, Ling; Gasparovich, Stephen R; Tao, Lin

    2013-07-01

    Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci.

  4. Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci

    PubMed Central

    Pavlova, Sylvia I.; Jin, Ling; Gasparovich, Stephen R.

    2013-01-01

    Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci. PMID:23637459

  5. Training-induced elevations in extracellular lactate in hippocampus and striatum: Dissociations by cognitive strategy and type of reward.

    PubMed

    Newman, Lori A; Scavuzzo, Claire J; Gold, Paul E; Korol, Donna L

    2017-01-01

    Recent evidence suggests that astrocytes convert glucose to lactate, which is released from the astrocytes and supports learning and memory. This report takes a multiple memory perspective to test the role of astrocytes in cognition using real-time lactate measurements during learning and memory. Extracellular lactate levels in the hippocampus or striatum were determined with lactate biosensors while rats were learning place (hippocampus-sensitive) or response (striatum-sensitive) versions of T-mazes. In the first experiment, rats were trained on the place and response tasks to locate a food reward. Extracellular lactate levels in the hippocampus increased beyond those of feeding controls during place training but not during response training. However, striatal lactate levels did not increase beyond those of controls when rats were trained on either the place or the response version of the maze. Because food ingestion itself increased blood glucose and brain lactate levels, the contribution of feeding may have confounded the brain lactate measures. Therefore, we conducted a second similar experiment using water as the reward. A very different pattern of lactate responses to training emerged when water was used as the task reward. First, provision of water itself did not result in large increases in either brain or blood lactate levels. Moreover, extracellular lactate levels increased in the striatum during response but not place learning, whereas extracellular lactate levels in the hippocampus did not differ across tasks. The findings from the two experiments suggest that the relative engagement of the hippocampus and striatum dissociates not only by task but also by reward type. The divergent lactate responses of the hippocampus and striatum in place and response tasks under different reward conditions may reflect ethological constraints tied to foraging for food and water. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Fabrication of Flexible Arrayed Lactate Biosensor Based on Immobilizing LDH-NAD⁺ on NiO Film Modified by GO and MBs.

    PubMed

    Chou, Jung-Chuan; Yan, Siao-Jie; Liao, Yi-Hung; Lai, Chih-Hsien; Wu, You-Xiang; Wu, Cian-Yi; Chen, Hsiang-Yi; Huang, Hong-Yu; Wu, Tong-Yu

    2017-07-12

    We proposed the flexible arrayed lactate biosensor based on immobilizing l-lactate dehydrogenase (LDH) and nicotinamide adenine dinucleotide ( NAD + ) on nickel oxide (NiO) film, and which the average sensitivity could be enhanced by using graphene oxide (GO) and magnetic beads (MBs). By using GO and MBs, it exhibits excellent sensitivity (45.397 mV/mM) with a linearity of 0.992 in a range of 0.2 mM to 3 mM. According to the results of electrochemical impedance spectroscopy (EIS), the electron transfer resistance of LDH- NAD + -MBs/GPTS/GO/NiO film was smaller than those of LDH-NAD⁺/GPTS/GO/NiO film and LDH- NAD + /GPTS/NiO film, and it presented the outstanding electron transfer ability. After that, the limit of detection, anti-interference effect and bending test were also investigated.

  7. Serum Lactate Predicts Adverse Outcomes in Emergency Department Patients With and Without Infection.

    PubMed

    Oedorf, Kimie; Day, Danielle E; Lior, Yotam; Novack, Victor; Sanchez, Leon D; Wolfe, Richard E; Kirkegaard, Hans; Shapiro, Nathan I; Henning, Daniel J

    2017-02-01

    Lactate levels are increasingly used to risk stratify emergency department (ED) patients with and without infection. Whether a serum lactate provides similar prognostic value across diseases is not fully elucidated. This study assesses the prognostic value of serum lactate in ED patients with and without infection to both report and compare relative predictive value across etiologies. We conducted a prospective, observational study of ED patients displaying abnormal vital signs (AVS) (heart rate ≥130 bpm, respiratory rate ≥24 bpm, shock index ≥1, and/or systolic blood pressure <90 mmHg). The primary outcome, deterioration, was a composite of acute renal failure, non-elective intubation, vasopressor administration or in-hospital mortality. Of the 1,152 patients with AVS who were screened, 488 patients met the current study criteria: 34% deteriorated and 12.5% died. The deterioration rate was 88/342 (26%, 95% CI: 21 - 30%) for lactate < 2.5 mmol/L, 47/90 (52%, 42 - 63%) for lactate 2.5 - 4.0 mmol/L, and 33/46 (72%, 59 - 85%) for lactate >4.0mmol/L. Trended stratified lactate levels were associated with deterioration for both infected (p<0.01) and non-infected (p<0.01) patients. In the logistic regression models, lactate > 4mmol/L was an independent predictor of deterioration for patients with infection (OR 4.8, 95% CI: 1.7 - 14.1) and without infection (OR 4.4, 1.7 - 11.5). Lactate levels can risk stratify patients with AVS who have increased risk of adverse outcomes regardless of infection status.

  8. Exposure to low levels of hydrogen sulfide elevates circulating glucose in maternal rats

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hayden, L.J.; Goeden, H.; Roth, S.H.

    1990-09-01

    Although the lethal effect of hydrogen sulfide (H{sub 2}S) has long been known, the results of exposure to low levels of H{sub 2}S have not been well documented. Rat dams and pups were exposed to low levels of H{sub 2}S (less than or equal to 75 ppm) from d 1 of gestation until d 21 postpartum and analyzed for changes in circulating enzymatic activity and metabolites. Blood glucose was significantly elevated in maternal blood on d 21 postpartum at all exposure levels. This increase in glucose was accompanied by a possible decrease in serum triglyceride in the pups and inmore » the dams on d 21 postpartum. There was no evidence of alterations in serum alkaline phosphatase, lactate dehydrogenase, or serum glutamate oxaloacetate transaminase.« less

  9. Effect of dietary starch level and high rumen-undegradable protein on endocrine-metabolic status, milk yield, and milk composition in dairy cows during early and late lactation.

    PubMed

    Piccioli-Cappelli, F; Loor, J J; Seal, C J; Minuti, A; Trevisi, E

    2014-12-01

    Diet composition defines the amount and type of nutrients absorbed by dairy cows. Endocrine-metabolic interactions can influence these parameters, and so nutrient availability for the mammary gland can significantly vary and affect milk yield and its composition. Six dairy cows in early and then late lactation received, for 28 d in a changeover design, 2 diets designed to provide, within the same stage of lactation, similar amounts of rumen fermentable material but either high starch plus sugar (HS) content or low starch plus sugar content (LS). All diets had similar dietary crude protein and calculated supply of essential amino acids. Dry matter intake within each stage of lactation was similar between groups. Milk yield was similar between groups in early lactation, whereas a higher milk yield was observed in late lactation when feeding HS. At the metabolic level, the main difference observed between the diets in both stages of lactation was lower blood glucose in cows fed LS. The lower glucose availability during consumption of LS caused substantial modifications in the circulating and postprandial pattern of metabolic hormones. Feeding LS versus HS resulted in an increase in the ratio of bovine somatotropin to insulin. This increased mobilization of lipid reserves resulted in higher blood concentrations of nonesterified fatty acids and β-hydroxybutyrate, which contributed to the higher milk fat content in both stages of lactation in the LS group. This greater recourse to body fat stores was confirmed by the greater loss of body weight during early lactation and the slower recovery of body weight in late lactation in cows fed LS. The lower insulin to glucagon ratio observed in cows fed LS in early and late lactation likely caused an increase in hepatic uptake and catabolism of amino acids, as confirmed by the higher blood urea concentrations. Despite the higher catabolism of amino acids in LS in early lactation, similar milk protein output was observed for both

  10. Inhibition effects of furfural on alcohol dehydrogenase, aldehyde dehydrogenase and pyruvate dehydrogenase.

    PubMed Central

    Modig, Tobias; Lidén, Gunnar; Taherzadeh, Mohammad J

    2002-01-01

    The kinetics of furfural inhibition of the enzymes alcohol dehydrogenase (ADH; EC 1.1.1.1), aldehyde dehydrogenase (AlDH; EC 1.2.1.5) and the pyruvate dehydrogenase (PDH) complex were studied in vitro. At a concentration of less than 2 mM furfural was found to decrease the activity of both PDH and AlDH by more than 90%, whereas the ADH activity decreased by less than 20% at the same concentration. Furfural inhibition of ADH and AlDH activities could be described well by a competitive inhibition model, whereas the inhibition of PDH was best described as non-competitive. The estimated K(m) value of AlDH for furfural was found to be about 5 microM, which was lower than that for acetaldehyde (10 microM). For ADH, however, the estimated K(m) value for furfural (1.2 mM) was higher than that for acetaldehyde (0.4 mM). The inhibition of the three enzymes by 5-hydroxymethylfurfural (HMF) was also measured. The inhibition caused by HMF of ADH was very similar to that caused by furfural. However, HMF did not inhibit either AlDH or PDH as severely as furfural. The inhibition effects on the three enzymes could well explain previously reported in vivo effects caused by furfural and HMF on the overall metabolism of Saccharomyces cerevisiae, suggesting a critical role of these enzymes in the observed inhibition. PMID:11964178

  11. Droplet Microfluidic Platform for the Determination of Single-Cell Lactate Release.

    PubMed

    Mongersun, Amy; Smeenk, Ian; Pratx, Guillem; Asuri, Prashanth; Abbyad, Paul

    2016-03-15

    Cancer cells release high levels of lactate that has been correlated to increased metastasis and tumor recurrence. Single-cell measurements of lactate release can identify malignant cells and help decipher metabolic cancer pathways. We present here a novel droplet microfluidic method that allows the fast and quantitative determination of lactate release in many single cells. Using passive forces, droplets encapsulated cells are positioned in an array. The single-cell lactate release rate is determined from the increase in droplet fluorescence as the lactate is enzymatically converted to a fluorescent product. The method is used to measure the cell-to-cell variance of lactate release in K562 leukemia and U87 glioblastoma cancer cell lines and under the chemical inhibition of lactate efflux. The technique can be used in the study of cancer biology, but more broadly in cell biology, to capture the full range of stochastic variations in glycolysis activity in heterogeneous cell populations in a repeatable and high-throughput manner.

  12. Renal Cortical Pyruvate Depletion during AKI

    PubMed Central

    Johnson, Ali C.M.; Becker, Kirsten

    2014-01-01

    Pyruvate is a key intermediary in energy metabolism and can exert antioxidant and anti-inflammatory effects. However, the fate of pyruvate during AKI remains unknown. Here, we assessed renal cortical pyruvate and its major determinants (glycolysis, gluconeogenesis, pyruvate dehydrogenase [PDH], and H2O2 levels) in mice subjected to unilateral ischemia (15–60 minutes; 0–18 hours of vascular reflow) or glycerol-induced ARF. The fate of postischemic lactate, which can be converted back to pyruvate by lactate dehydrogenase, was also addressed. Ischemia and glycerol each induced persistent pyruvate depletion. During ischemia, decreasing pyruvate levels correlated with increasing lactate levels. During early reperfusion, pyruvate levels remained depressed, but lactate levels fell below control levels, likely as a result of rapid renal lactate efflux. During late reperfusion and glycerol-induced AKI, pyruvate depletion corresponded with increased gluconeogenesis (pyruvate consumption). This finding was underscored by observations that pyruvate injection increased renal cortical glucose content in AKI but not normal kidneys. AKI decreased PDH levels, potentially limiting pyruvate to acetyl CoA conversion. Notably, pyruvate therapy mitigated the severity of AKI. This renoprotection corresponded with increases in cytoprotective heme oxygenase 1 and IL-10 mRNAs, selective reductions in proinflammatory mRNAs (e.g., MCP-1 and TNF-α), and improved tissue ATP levels. Paradoxically, pyruvate increased cortical H2O2 levels. We conclude that AKI induces a profound and persistent depletion of renal cortical pyruvate, which may induce additional injury. PMID:24385590

  13. Conformational heterogeneity within the Michaelis complex of lactate dehydrogenase†

    PubMed Central

    Deng, Hua; Vu, Dung V.; Clinch, Keith; Desamero, Ruel; Dyer, R. Brian; Callender, Robert

    2011-01-01

    A series of isotope edited IR measurements, both static as well as temperature jump relaxation spectroscopy, are performed on lactate dehydrogenase (LDH) to determine the ensemble of structures available to its Michaelis complex. There clearly has been a substantial reduction in the number of states available to the pyruvate substrate (as modeled by the substrate mimic, oxamate) and NADH when bound to protein compared to dissolved in solution, as determined by the bandwidths and positions of the critical C2=O band of bound substrate mimic and the C4-H stretch of NADH reduced nicotinamide group. Moreover, it is found that a strong ionic bond (characterized by a signature IR band discovered in this study) is formed between the carboxyl group of bound pyruvate with (presumably) Arg171, forming a strong ‘anchor’ within the protein matrix. However, conformational heterogeneity within the Michaelis complex is found that has an impact on both catalytic efficiency and thermodynamics of the enzyme. PMID:21568287

  14. Guinea-pig liver testosterone 17 beta-dehydrogenase (NADP+) and aldehyde reductase exhibit benzene dihydrodiol dehydrogenase activity.

    PubMed Central

    Hara, A; Hayashibara, M; Nakayama, T; Hasebe, K; Usui, S; Sawada, H

    1985-01-01

    We have kinetically and immunologically demonstrated that testosterone 17 beta-dehydrogenase (NADP+) isoenzymes (EC 1.1.1.64) and aldehyde reductase (EC 1.1.1.2) from guinea-pig liver catalyse the oxidation of benzene dihydrodiol (trans-1,2-dihydroxycyclohexa-3,5-diene) to catechol. One isoenzyme of testosterone 17 beta-dehydrogenase, which has specificity for 5 beta-androstanes, oxidized benzene dihydrodiol at a 3-fold higher rate than 5 beta-dihydrotestosterone, and showed a more than 4-fold higher affinity for benzene dihydrodiol and Vmax. value than did another isoenzyme, which exhibits specificity for 5 alpha-androstanes, and aldehyde reductase. Immunoprecipitation of guinea-pig liver cytosol with antisera against the testosterone 17 beta-dehydrogenase isoenzymes and aldehyde reductase indicated that most of the benzene dihydrodiol dehydrogenase activity in the tissue is due to testosterone 17 beta-dehydrogenase. PMID:2983661

  15. [Diagnostic value of detection of blood levels of lactate, pyruvate and 2,3-diphosphoglycerate in children with diabetes mellitus].

    PubMed

    Marchenko, L F; Baturin, A A; Terent'eva, E A

    1991-01-01

    Measurements were made of lactate, pyruvate and 2,3-diphosphoglycerate in 69 children admitted to the hospital in a state of diabetic ketoacidosis of different intensity. Depending on the intensity of metabolic abnormalities, the content of lactate and pyruvate was found to be increased, whereas that of 2,3-diphosphoglycerate to be lowered. Measurements of the content of lactate and the lactate/pyruvate ratio enables carrying out differential diagnosis between the ketoacidotic and lactacidotic varieties of diabetic coma.

  16. Evaluation of three parasite lactate dehydrogenase-based rapid diagnostic tests for the diagnosis of falciparum and vivax malaria

    PubMed Central

    Ashley, Elizabeth A; Touabi, Malek; Ahrer, Margareta; Hutagalung, Robert; Htun, Khayae; Luchavez, Jennifer; Dureza, Christine; Proux, Stephane; Leimanis, Mara; Lwin, Myo Min; Koscalova, Alena; Comte, Eric; Hamade, Prudence; Page, Anne-Laure; Nosten, François; Guerin, Philippe J

    2009-01-01

    Background In areas where non-falciparum malaria is common rapid diagnostic tests (RDTs) capable of distinguishing malaria species reliably are needed. Such tests are often based on the detection of parasite lactate dehydrogenase (pLDH). Methods In Dawei, southern Myanmar, three pLDH based RDTs (CareStart™ Malaria pLDH (Pan), CareStart™ Malaria pLDH (Pan, Pf) and OptiMAL-IT®)were evaluated in patients presenting with clinically suspected malaria. Each RDT was read independently by two readers. A subset of patients with microscopically confirmed malaria had their RDTs repeated on days 2, 7 and then weekly until negative. At the end of the study, samples of study batches were sent for heat stability testing. Results Between August and November 2007, 1004 patients aged between 1 and 93 years were enrolled in the study. Slide microscopy (the reference standard) diagnosed 213 Plasmodium vivax (Pv) monoinfections, 98 Plasmodium falciparum (Pf) mono-infections and no malaria in 650 cases. The sensitivities (sens) and specificities (spec), of the RDTs for the detection of malaria were- CareStart Malaria™ pLDH (Pan) test: sens 89.1% [CI95 84.2-92.6], spec 97.6% [CI95 96.5-98.4] OptiMal-IT®: Pf+/- other species detection: sens 95.2% [CI95 87.5-98.2], spec 94.7% [CI95 93.3-95.8]; non-Pf detection alone: sens 89.6% [CI95 83.6-93.6], spec 96.5% [CI95 94.8-97.7] CareStart Malaria™ pLDH (Pan, Pf): Pf+/- other species: sens 93.5% [CI9585.4-97.3], spec 97.4% [95.9-98.3]; non-Pf: sens 78.5% [CI9571.1-84.4], spec 97.8% [CI95 96.3-98.7] Inter-observer agreement was excellent for all tests (kappa > 0.9). The median time for the RDTs to become negative was two days for the CareStart™ Malaria tests and seven days for OptiMAL-IT®. Tests were heat stable up to 90 days except for OptiMAL-IT® (Pf specific pLDH stable to day 20 at 35°C). Conclusion None of the pLDH-based RDTs evaluated was able to detect non-falciparum malaria with high sensitivity, particularly at low

  17. Evaluation of three parasite lactate dehydrogenase-based rapid diagnostic tests for the diagnosis of falciparum and vivax malaria.

    PubMed

    Ashley, Elizabeth A; Touabi, Malek; Ahrer, Margareta; Hutagalung, Robert; Htun, Khayae; Luchavez, Jennifer; Dureza, Christine; Proux, Stephane; Leimanis, Mara; Lwin, Myo Min; Koscalova, Alena; Comte, Eric; Hamade, Prudence; Page, Anne-Laure; Nosten, François; Guerin, Philippe J

    2009-10-27

    In areas where non-falciparum malaria is common rapid diagnostic tests (RDTs) capable of distinguishing malaria species reliably are needed. Such tests are often based on the detection of parasite lactate dehydrogenase (pLDH). In Dawei, southern Myanmar, three pLDH based RDTs (CareStart Malaria pLDH (Pan), CareStart Malaria pLDH (Pan, Pf) and OptiMAL-IT)were evaluated in patients presenting with clinically suspected malaria. Each RDT was read independently by two readers. A subset of patients with microscopically confirmed malaria had their RDTs repeated on days 2, 7 and then weekly until negative. At the end of the study, samples of study batches were sent for heat stability testing. Between August and November 2007, 1004 patients aged between 1 and 93 years were enrolled in the study. Slide microscopy (the reference standard) diagnosed 213 Plasmodium vivax (Pv) monoinfections, 98 Plasmodium falciparum (Pf) mono-infections and no malaria in 650 cases. The sensitivities (sens) and specificities (spec), of the RDTs for the detection of malaria were- CareStart Malaria pLDH (Pan) test: sens 89.1% [CI95 84.2-92.6], spec 97.6% [CI95 96.5-98.4]. OptiMal-IT: Pf+/- other species detection: sens 95.2% [CI95 87.5-98.2], spec 94.7% [CI95 93.3-95.8]; non-Pf detection alone: sens 89.6% [CI95 83.6-93.6], spec 96.5% [CI95 94.8-97.7]. CareStart Malaria pLDH (Pan, Pf): Pf+/- other species: sens 93.5% [CI95 85.4-97.3], spec 97.4% [95.9-98.3]; non-Pf: sens 78.5% [CI95 71.1-84.4], spec 97.8% [CI95 96.3-98.7]. Inter-observer agreement was excellent for all tests (kappa > 0.9). The median time for the RDTs to become negative was two days for the CareStart Malaria tests and seven days for OptiMAL-IT. Tests were heat stable up to 90 days except for OptiMAL-IT (Pf specific pLDH stable to day 20 at 35 degrees C). None of the pLDH-based RDTs evaluated was able to detect non-falciparum malaria with high sensitivity, particularly at low parasitaemias. OptiMAL-IT performed best overall and

  18. Effects of molasses and corn grain at 2 levels of ruminally degradable protein on lactating cow ruminal fermentation and rumen content mass

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate lactating dairy cow ruminal fermentation and rumen content mass with diets containing molasses (M) or finely ground dry corn grain at 3 levels of M (0, 5.25, 10.5% DM) and with differing levels of ruminally degradable protein (+RDP or –RDP). Twelve ruminal...

  19. Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.

    PubMed

    Bublitz, Caroline; Renno, Ana Claudia Muniz; Ramos, Rodrigo Santin; Assis, Livia; Sellera, Carlos Alberto Cyrillo; Trimer, Renata; Borghi-Silva, Audrey; Arena, Ross; Guizilini, Solange

    2016-08-01

    The objective of the present study is to evaluate the acute effects of low-level laser therapy (LLLT) on functional capacity, perceived exertion, and blood lactate in hospitalized patients with heart failure (HF). Patients diagnosed with systolic HF (left ventricular ejection fraction <45 %) were randomized and allocated prospectively into two groups: placebo LLLT group (n = 10)-subjects who were submitted to placebo laser and active LLLT group (n = 10)-subjects who were submitted to active laser. The 6-min walk test (6MWT) was performed, and blood lactate was determined at rest (before LLLT application and 6MWT), immediately after the exercise test (time 0) and recovery (3, 6, and 30 min). A multi-diode LLLT cluster probe (DMC, São Carlos, Brazil) was used. Both groups increased 6MWT distance after active or placebo LLLT application compared to baseline values (p = 0.03 and p = 0.01, respectively); however, no difference was observed during intergroup comparison. The active LLLT group showed a significant reduction in the perceived exertion Borg (PEB) scale compared to the placebo LLLT group (p = 0.006). In addition, the group that received active LLLT showed no statistically significant difference for the blood lactate level through the times analyzed. The placebo LLLT group demonstrated a significant increase in blood lactate between the rest and recovery phase (p < 0.05). Acute effects of LLLT irradiation on skeletal musculature were not able to improve the functional capacity of hospitalized patients with HF, although it may favorably modulate blood lactate metabolism and reduce perceived muscle fatigue.

  20. Attentive processes, blood lactate and CrossFit®.

    PubMed

    Perciavalle, Valentina; Marchetta, Nunzio Salvatore; Giustiniani, Salvatore; Borbone, Carlo; Perciavalle, Vincenzo; Petralia, Maria Cristina; Buscemi, Andrea; Coco, Marinella

    2016-11-01

    To analyze the influences of blood lactate produced during a specific session of CrossFit® on intensity and selectivity of attention. The first was evaluated by measuring the reaction time and the second by analyzing divided attention with a dual task. Fifteen male professionals of CrossFit® volunteered in the study. The training session was the Workout Of the Day (WOD) called 15.5, marked as: 27-21-15-9 repetitions (without recovery) in term of calories measured by using a rowing ergometer (e.g. 27 rowed calories) and in term of barbell full squats (raising a weight of 43 kg for men and of 29.5 kg for women). Blood lactate, blood glucose, reaction time, execution time of a dual task, number of errors and number of omissions were measured at rest, at the conclusion of the session and 15 minutes after its end. The levels of the blood lactate before the start of the session were considerably higher than those which normally occur at rest (<2 mmol /L), with a mean value of 4.5 mmol /l (± 1.99 SD). At the end of the workout session the blood lactate exhibited a significant increase, reaching a mean value of 13.8 mmol /l (± 1.18 SD) and then returning to values similar to the initial ones after 15 minutes. Blood glucose did not exhibit any statistically significant differences during the session. Reaction time, execution time, number of errors and number of omissions exhibited a significant worsening concomitantly with the increase in blood lactate. Athletes practicing CrossFit®, with high levels of blood lactate even at rest, should consequently have attentional performances somewhat limited.

  1. Selenium and Antioxidant Status in Dairy Cows at Different Stages of Lactation.

    PubMed

    Gong, Jian; Xiao, Min

    2016-05-01

    Thirty-five multiparous Holstein cows averaging 550 ± 50 kg of body weight and in 2 to 4 parity were divided into three groups according to lactation stage (group A: nine cows from 4 to 1 weeks prepartum; group B: 11 cows from 1 to 30 days postpartum; group C: 15 cows from 30 to 100 days postpartum). Selenium concentration, malondialdehyde (MDA) level, glutathione peroxidase (GSH-Px) activity, thioredoxin reductase (TrxR) activity, and total antioxidant status (TAS) in serum were determined to evaluate selenium and antioxidant status in dairy cows at different stages of lactation. The results showed that mean serum selenium concentration, MDA level, and GSH-Px activity of cows in early lactation increased significantly (P < 0.05) when compared with cows in the dry period and peak lactation. Conversely, serum TrxR activity and TAS declined during this period (P < 0.05). The increase of serum MDA level during early lactation indicate that the reactive oxygen species, including lipid hydroperoxides, increase in this period, thus placing the cows at a greater risk of oxidative stress. The significant decrease in TrxR activity that is accompanied with a decrease in TAS during early lactation suggests that dairy cows have low antioxidant defense in this period and TrxR may be an important antioxidant defense mechanism in transition dairy cows.

  2. Characterization of human DHRS6, an orphan short chain dehydrogenase/reductase enzyme: a novel, cytosolic type 2 R-beta-hydroxybutyrate dehydrogenase.

    PubMed

    Guo, Kunde; Lukacik, Petra; Papagrigoriou, Evangelos; Meier, Marc; Lee, Wen Hwa; Adamski, Jerzy; Oppermann, Udo

    2006-04-14

    Human DHRS6 is a previously uncharacterized member of the short chain dehydrogenases/reductase family and displays significant homologies to bacterial hydroxybutyrate dehydrogenases. Substrate screening reveals sole NAD(+)-dependent conversion of (R)-hydroxybutyrate to acetoacetate with K(m) values of about 10 mm, consistent with plasma levels of circulating ketone bodies in situations of starvation or ketoacidosis. The structure of human DHRS6 was determined at a resolution of 1.8 A in complex with NAD(H) and reveals a tetrameric organization with a short chain dehydrogenases/reductase-typical folding pattern. A highly conserved triad of Arg residues ("triple R" motif consisting of Arg(144), Arg(188), and Arg(205)) was found to bind a sulfate molecule at the active site. Docking analysis of R-beta-hydroxybutyrate into the active site reveals an experimentally consistent model of substrate carboxylate binding and catalytically competent orientation. GFP reporter gene analysis reveals a cytosolic localization upon transfection into mammalian cells. These data establish DHRS6 as a novel, cytosolic type 2 (R)-hydroxybutyrate dehydrogenase, distinct from its well characterized mitochondrial type 1 counterpart. The properties determined for DHRS6 suggest a possible physiological role in cytosolic ketone body utilization, either as a secondary system for energy supply in starvation or to generate precursors for lipid and sterol synthesis.

  3. Glucose uptake and lactate production in cells exposed to CoCl(2) and in cells overexpressing the Glut-1 glucose transporter.

    PubMed

    Hwang, Daw-Yang; Ismail-Beigi, Faramarz

    2002-03-15

    Glut-1-mediated glucose transport is augmented in response to a variety of conditions and stimuli. In this study we examined the metabolic fate of glucose in cells in which glucose transport is stimulated by exposure to CoCl(2), an agent that stimulates the expression of a set of hypoxia-responsive genes including several glycolytic enzymes and the Glut-1 glucose transporter. Similarly, we determined the metabolic fate of glucose in stably transfected cells overexpressing Glut-1. Exposure of Clone 9 liver cell line, 3T3-L1 fibroblasts, and C(2)C(12) myoblasts to CoCl(2) resulted in an increase glucose uptake and in the activity of glucose phosphorylation ("hexokinase") and lactate dehydrogenase. In cells treated with CoCl(2), the net increase in glucose taken up was accounted for by its near-complete conversion to lactate. Cells stably transfected to overexpress Glut-1 also exhibited enhanced net uptake of glucose with the near-complete conversion of the increased glucose taken up to lactate; however, the effect in these cells was observed in the absence of any change in the activity of two glycolytic enzymes examined. These findings suggest that in cells in which glucose transport is rate-limiting for glucose metabolism, enhancement of the glucose entry step per se results in a near-complete conversion of the extra glucose to lactate.

  4. Evaluation of Milk Trace Elements, Lactate Dehydrogenase, Alkaline Phosphatase and Aspartate Aminotransferase Activity of Subclinical Mastitis as and Indicator of Subclinical Mastitis in Riverine Buffalo (Bubalus bubalis).

    PubMed

    Guha, Anirban; Gera, Sandeep; Sharma, Anshu

    2012-03-01

    Mastitis is a highly morbid disease that requires detection at the subclinical stage. Tropical countries like India mainly depend on milch buffaloes for milk. The present study was conducted to investigate whether the trace minerals viz. copper (Cu), iron (Fe), zinc (Zn), cobalt (Co) and manganese (Mn) and enzyme activity of lactate dehydrogenase (LDH), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in riverine buffalo milk can be used as an indicator of subclinical mastitis (SCM) with the aim of developing suitable diagnostic kit for SCM. Trace elements and enzyme activity in milk were estimated with Atomic absorption Spectrophotometer, GBC 932 plus and biochemical methods, respectively. Somatic cell count (SCC) was done microscopically. The cultural examination revealed Gram positive bacteria as the most prevalent etiological agent. A statistically significant (p<0.01) increase in SCC, Fe, Zn, Co and LDH occurred in SCM milk containing gram positive bacterial agents only. ALP was found to be elevated in milk infected by both gram positive and negative bacteria. The percent sensitivity, specificity and accuracy, predictive values and likelihood ratios were calculated taking bacterial culture examination and SCC≥2×10(5) cells/ml of milk as the benchmark. Only ALP and Zn, the former being superior, were found to be suitable for diagnosis of SCM irrespective of etiological agents. LDH, Co and Fe can be introduced in the screening programs where Gram positive bacteria are omnipresent. It is recommended that both ALP and Zn be measured together in milk to diagnose buffalo SCM, irrespective of etiology.

  5. CYTOCHEMICAL LOCALIZATION OF TWO GLYCOLYTIC DEHYDROGENASES IN WHITE SKELETAL MUSCLE

    PubMed Central

    Fahimi, H. Dariush; Karnovsky, Morris J.

    1966-01-01

    The cytochemical localization, by conventional methods, of lactate and glyceraldehyde-3-phosphate dehydrogenases is limited, firstly, by the solubility of these enzymes in aqueous media and, secondly, by the dependence of the final electron flow from reduced nicotinamide-adenine dinucleotide (NADH) to the tetrazolium on tissue diaphorase activity: localization is therefore that of the diaphorase, which in rabbit adductor magnus is mitochondrial. NADH has been found to have great affinity to bind in the sarcoplasmic reticulum, and, therefore, if it is generated freely in the incubation media containing 2,2',5,5'-tetra-p-nitrophenyl-3,3'-(3,3'-dimethoxy-4,4'-phenylene)-ditetrazolium chloride (TNBT) and N-methyl phenazonium methyl sulfate (PMS), it can bind there and cause a false staining. Since such a production of NADH can readily occur in the incubation media for glycolytic dehydrogenases due to diffusion of these soluble enzymes from tissue sections, the prevention of enzyme solubilization is extremely important. Fixation in formaldehyde prevented such enzyme diffusion, while at the same time sufficient activity persisted to allow for adequate staining. The incubation media contained PMS, so that the staining system was largely independent of tissue diaphorase activity. Application of these methods to adductor magnus of rabbit revealed by light microscopy, for both enzymes, a fine network which was shown by electron microscopy to represent staining of the sarcoplasmic reticulum. Mitochondria also reacted. These findings add further support for the notion that the sarcoplasmic reticulum is probably involved in glycolytic activity. PMID:4288329

  6. Early lactation production, health, and welfare characteristics of cows selected for extended lactation.

    PubMed

    Lehmann, J O; Mogensen, L; Kristensen, T

    2017-02-01

    Some cows are able to achieve relatively high milk yields during extended lactations beyond 305 d in milk, and farmers may be able to use this potential by selecting the most suitable cows for an extended lactation. However, the decision to postpone insemination has to rely on information available in early lactation. The main objectives of this study were, therefore, to assess the association between the information available in early lactation and the relative milk production of cows on extended lactation, and to investigate if this information can be used to differentiate time of first insemination between cows. Data came from 4 Danish private herds practicing extended lactation in which some cows are selected to have a delayed time of planned first insemination. Average herd size varied from 93 to 157 cows, and milk yield varied from 7,842 to 12,315 kg of energy-corrected milk (ECM) per cow per year across herds. The analysis was based on 422 completed extended lactations (427 ± 87 d), and each lactation was assigned to 1 of 3 (low, medium, and high) milk performance groups (MPG) within parity group within herd based on a standardized lactation yield. For cows in the high MPG, peak ECM yield, and ECM yield at dry off were significantly greater, the relative reduction in milk yield between 60 and 305 d in milk was significantly smaller, and a smaller proportion had a body condition score (scale: 1-5) at dry off of 3.5 or greater compared with cows in low MPG. Previous lactation days in milk at peak ECM yield and ECM yield at dry off were higher, the relative reduction in milk yield between 60 and 305 d in milk was smaller, and the number of inseminations per conception was higher for multiparous cows in high MPG compared with low. Current lactation ECM yield at second and third milk recording were greater for cows in high MPG compared with low. A principal component analysis indicated that variables related to fertility, diseases, and milk yield explained most

  7. The effect of extracellular alkalinization on lactate metabolism of breast cancer stem cells: Overview of LDH-A, LDH-B, MCT1 and MCT4 gene expression

    NASA Astrophysics Data System (ADS)

    Neolaka, G. M. G.; Yustisia, I.; Sadikin, M.; Wanandi, S. I.

    2017-08-01

    Changes in the metabolic status of cancer cells are presumed to be correlated with the adjustment of these cells to extracellular changes. Cell glycolysis increases the production of intracellular lactate catalyzed by the lactate dehydrogenases, both LDH-A and LDH-B. An increase in intracellular lactate can affect extracellular pH balance through monocarboxylate transporters, particularly MCT1 and MCT4. This study aimed to analyze the effects of extracellular alkalinization on the lactate metabolism of human breast cancer stem cells (BCSCs). In this study, human primary BCSCs (CD24-/CD44+ cells) were treated with 100 mM sodium bicarbonate for 0.5, 24, and 48 h in DMEM F12/HEPES. After incubation, extracellular pH was measured and cells were harvested to extract the total RNA and protein. The expression of LDH-A, LDH-B, MCT1, and MCT4 mRNA genes were analyzed using qRT-PCR method. Our study shows that administration of sodium bicarbonate in the BCSC culture medium could increase extracellular pH. To balance the increase of extracellular pH, BCSCs regulated the expression of LDH-A, LDH-B, MCT1, and MCT4 genes. As the extracellular pH increases, the expression of LDH-A that converts pyruvate to lactate increased along with the increase of MCT 4 and MCT 1 expression, which act as lactate transporters. As the incubation time increases, the pH decreases, leading to the suppression of LDH-A and increase of LDH-B expression that converts lactate into pyruvate. Therefore, we suggest that the extracellular alkalinization by sodium bicarbonate in BCSCs affected the genes that regulate lactate metabolism.

  8. Lactate transport and signaling in the brain: potential therapeutic targets and roles in body–brain interaction

    PubMed Central

    Bergersen, Linda Hildegard

    2015-01-01

    Lactate acts as a ‘buffer' between glycolysis and oxidative metabolism. In addition to being exchanged as a fuel by the monocarboxylate transporters (MCTs) between cells and tissues with different glycolytic and oxidative rates, lactate may be a ‘volume transmitter' of brain signals. According to some, lactate is a preferred fuel for brain metabolism. Immediately after brain activation, the rate of glycolysis exceeds oxidation, leading to net production of lactate. At physical rest, there is a net efflux of lactate from the brain into the blood stream. But when blood lactate levels rise, such as in physical exercise, there is net influx of lactate from blood to brain, where the lactate is used for energy production and myelin formation. Lactate binds to the lactate receptor GPR81 aka hydroxycarboxylic acid receptor (HCAR1) on brain cells and cerebral blood vessels, and regulates the levels of cAMP. The localization and function of HCAR1 and the three MCTs (MCT1, MCT2, and MCT4) expressed in brain constitute the focus of this review. They are possible targets for new therapeutic drugs and interventions. The author proposes that lactate actions in the brain through MCTs and the lactate receptor underlie part of the favorable effects on the brain resulting from physical exercise. PMID:25425080

  9. Lactate transport and signaling in the brain: potential therapeutic targets and roles in body-brain interaction.

    PubMed

    Bergersen, Linda Hildegard

    2015-02-01

    Lactate acts as a 'buffer' between glycolysis and oxidative metabolism. In addition to being exchanged as a fuel by the monocarboxylate transporters (MCTs) between cells and tissues with different glycolytic and oxidative rates, lactate may be a 'volume transmitter' of brain signals. According to some, lactate is a preferred fuel for brain metabolism. Immediately after brain activation, the rate of glycolysis exceeds oxidation, leading to net production of lactate. At physical rest, there is a net efflux of lactate from the brain into the blood stream. But when blood lactate levels rise, such as in physical exercise, there is net influx of lactate from blood to brain, where the lactate is used for energy production and myelin formation. Lactate binds to the lactate receptor GPR81 aka hydroxycarboxylic acid receptor (HCAR1) on brain cells and cerebral blood vessels, and regulates the levels of cAMP. The localization and function of HCAR1 and the three MCTs (MCT1, MCT2, and MCT4) expressed in brain constitute the focus of this review. They are possible targets for new therapeutic drugs and interventions. The author proposes that lactate actions in the brain through MCTs and the lactate receptor underlie part of the favorable effects on the brain resulting from physical exercise.

  10. Reconstitution of the Escherichia coli pyruvate dehydrogenase complex.

    PubMed Central

    Reed, L J; Pettit, F H; Eley, M H; Hamilton, L; Collins, J H; Oliver, R M

    1975-01-01

    The binding of pyruvate dehydrogenase and dihydrolipoyl dehydrogenase (flavoprotein) to dihydrolipoyl transacetylase, the core enzyme of the E. coli pyruvate dehydrogenase complex [EC 1.2.4.1:pyruvate:lipoate oxidoreductase (decaryboxylating and acceptor-acetylating)], has been studied using sedimentation equilibrium analysis and radioactive enzymes in conjunction with gel filtration chromatography. The results show that the transacetylase, which consists of 24 apparently identical polypeptide chains organized into a cube-like structure, has the potential to bind 24 pyruvate dehydrogenase dimers in the absence of flavoprotein and 24 flavoprotein dimers in the absence of pyruvate dehydrogenase. The results of reconstitution experiments, utilizing binding and activity measurements, indicate that the transacetylase can accommodate a total of only about 12 pyruvate dehydrogenase dimers and six flavoprotein dimers and that this stoichiometry, which is the same as that of the native pyruvate dehydrogenase complex, produces maximum activity. It appears that steric hindrance between the relatively bulky pyruvate dehydrogenase and flavoprotein molecules prevents the transacetylase from binding 24 molecules of each ligand. A structural model for the native and reconstituted pyruvate dehydrogenase complexes is proposed in which the 12 pyruvate dehydrogenase dimers are distributed symmetrically on the 12 edges of the transacetylase cube and the six flavoprotein dimers are distributed in the six faces of the cube. Images PMID:1103138

  11. Defining lactation acuity to improve patient safety and outcomes.

    PubMed

    Mannel, Rebecca

    2011-05-01

    While substantial evidence exists identifying risks factors associated with premature weaning from breastfeeding, there are no previously published definitions of patient acuity in the lactation field. This article defines evidence-based levels of lactation acuity based on maternal and infant characteristics. Patient acuity, matching severity of illness to intensity of care required, is an important determinant of patient safety and outcomes. It is often used as part of a patient classification system to determine staffing needs and acceptable workloads in health care settings. As acuity increases, more resources, including more skilled clinicians, are needed to provide optimal care. Developing an evidence-based definition of lactation acuity can help to standardize terminology, more effectively distribute health care staff resources, encourage research to verify the validity and reliability of lactation acuity, and potentially improve breastfeeding initiation and duration rates.

  12. Isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma.

    PubMed

    Kipp, Benjamin R; Voss, Jesse S; Kerr, Sarah E; Barr Fritcher, Emily G; Graham, Rondell P; Zhang, Lizhi; Highsmith, W Edward; Zhang, Jun; Roberts, Lewis R; Gores, Gregory J; Halling, Kevin C

    2012-10-01

    Somatic mutations in isocitrate dehydrogenase 1 and 2 genes are common in gliomas and help stratify patients with brain cancer into histologic and molecular subtypes. However, these mutations are considered rare in other solid tumors. The aims of this study were to determine the frequency of isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma and to assess histopathologic differences between specimens with and without an isocitrate dehydrogenase mutation. We sequenced 94 formalin-fixed, paraffin-embedded cholangiocarcinoma (67 intrahepatic and 27 extrahepatic) assessing for isocitrate dehydrogenase 1 (codon 132) and isocitrate dehydrogenase 2 (codons 140 and 172) mutations. Multiple histopathologic characteristics were also evaluated and compared with isocitrate dehydrogenase 1/2 mutation status. Of the 94 evaluated specimens, 21 (22%) had a mutation including 14 isocitrate dehydrogenase 1 and 7 isocitrate dehydrogenase 2 mutations. Isocitrate dehydrogenase mutations were more frequently observed in intrahepatic cholangiocarcinoma than in extrahepatic cholangiocarcinoma (28% versus 7%, respectively; P = .030). The 14 isocitrate dehydrogenase 1 mutations were R132C (n = 9), R132S (n = 2), R132G (n = 2), and R132L (n = 1). The 7 isocitrate dehydrogenase 2 mutations were R172K (n = 5), R172M (n = 1), and R172G (n = 1). Isocitrate dehydrogenase mutations were more frequently observed in tumors with clear cell change (P < .001) and poorly differentiated histology (P = .012). The results of this study show for the first time that isocitrate dehydrogenase 1 and 2 genes are mutated in cholangiocarcinoma. The results of this study are encouraging because it identifies a new potential target for genotype-directed therapeutic trials and may represent a potential biomarker for earlier detection of cholangiocarcinoma in a subset of cases. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Hepatic transcriptional changes in critical genes for gluconeogenesis following castration of bulls

    PubMed Central

    Fassah, Dilla Mareistia; Jeong, Jin Young

    2018-01-01

    Objective This study was performed to understand transcriptional changes in the genes involved in gluconeogenesis and glycolysis pathways following castration of bulls. Methods Twenty Korean bulls were weaned at average 3 months of age, and castrated at 6 months. Liver tissues were collected from bulls (n = 10) and steers (n = 10) of Korean cattle, and hepatic gene expression levels were measured using quantitative real-time polymerase chain reaction. We examined hepatic transcription levels of genes encoding enzymes for irreversible reactions in both gluconeogenesis and glycolysis as well as genes encoding enzymes for the utilization of several glucogenic substrates. Correlations between hepatic gene expression and carcass characteristics were performed to understand their associations. Results Castration increased the mRNA (3.6 fold; p<0.01) and protein levels (1.4 fold; p< 0.05) of pyruvate carboxylase and mitochondrial phosphoenolpyruvate carboxykinase genes (1.7 fold; p<0.05). Hepatic mRNA levels of genes encoding the glycolysis enzymes were not changed by castration. Castration increased mRNA levels of both lactate dehydrogenase A (1.5 fold; p<0.05) and lactate dehydrogenase B (2.2 fold; p<0.01) genes for lactate utilization. Castration increased mRNA levels of glycerol kinase (2.7 fold; p<0.05) and glycerol-3-phosphate dehydrogenase 1 (1.5 fold; p<0.05) genes for glycerol utilization. Castration also increased mRNA levels of propionyl-CoA carboxylase beta (mitochondrial) (3.5 fold; p<0.01) and acyl-CoA synthetase short chain family member 3 (1.3 fold; p = 0.06) genes for propionate incorporation. Conclusion Castration increases transcription levels of critical genes coding for enzymes involved in irreversible gluconeogenesis reactions from pyruvate to glucose and enzymes responsible for incorporation of glucogenic substrates including lactate, glycerol, and propionate. Hepatic gluconeogenic gene expression levels were associated with intramuscular fat

  14. Hepatic transcriptional changes in critical genes for gluconeogenesis following castration of bulls.

    PubMed

    Fassah, Dilla Mareistia; Jeong, Jin Young; Baik, Myunggi

    2018-04-01

    This study was performed to understand transcriptional changes in the genes involved in gluconeogenesis and glycolysis pathways following castration of bulls. Twenty Korean bulls were weaned at average 3 months of age, and castrated at 6 months. Liver tissues were collected from bulls (n = 10) and steers (n = 10) of Korean cattle, and hepatic gene expression levels were measured using quantitative real-time polymerase chain reaction. We examined hepatic transcription levels of genes encoding enzymes for irreversible reactions in both gluconeogenesis and glycolysis as well as genes encoding enzymes for the utilization of several glucogenic substrates. Correlations between hepatic gene expression and carcass characteristics were performed to understand their associations. Castration increased the mRNA (3.6 fold; p<0.01) and protein levels (1.4 fold; p< 0.05) of pyruvate carboxylase and mitochondrial phosphoenolpyruvate carboxykinase genes (1.7 fold; p<0.05). Hepatic mRNA levels of genes encoding the glycolysis enzymes were not changed by castration. Castration increased mRNA levels of both lactate dehydrogenase A (1.5 fold; p<0.05) and lactate dehydrogenase B (2.2 fold; p<0.01) genes for lactate utilization. Castration increased mRNA levels of glycerol kinase (2.7 fold; p<0.05) and glycerol-3-phosphate dehydrogenase 1 (1.5 fold; p<0.05) genes for glycerol utilization. Castration also increased mRNA levels of propionyl-CoA carboxylase beta (mitochondrial) (3.5 fold; p<0.01) and acyl-CoA synthetase short chain family member 3 (1.3 fold; p = 0.06) genes for propionate incorporation. Castration increases transcription levels of critical genes coding for enzymes involved in irreversible gluconeogenesis reactions from pyruvate to glucose and enzymes responsible for incorporation of glucogenic substrates including lactate, glycerol, and propionate. Hepatic gluconeogenic gene expression levels were associated with intramuscular fat deposition.

  15. Partial nucleotide sequences, and routine typing by polymerase chain reaction-restriction fragment length polymorphism, of the brown trout (Salmo trutta) lactate dehydrogenase, LDH-C1*90 and *100 alleles.

    PubMed

    McMeel, O M; Hoey, E M; Ferguson, A

    2001-01-01

    The cDNA nucleotide sequences of the lactate dehydrogenase alleles LDH-C1*90 and *100 of brown trout (Salmo trutta) were found to differ at position 308 where an A is present in the *100 allele but a G is present in the *90 allele. This base substitution results in an amino acid change from aspartic acid at position 82 in the LDH-C1 100 allozyme to a glycine in the 90 allozyme. Since aspartic acid has a net negative charge whilst glycine is uncharged, this is consistent with the electrophoretic observation that the LDH-C1 100 allozyme has a more anodal mobility relative to the LDH-C1 90 allozyme. Based on alignment of the cDNA sequence with the mouse genomic sequence, a local primer set was designed, incorporating the variable position, and was found to give very good amplification with brown trout genomic DNA. Sequencing of this fragment confirmed the difference in both homozygous and heterozygous individuals. Digestion of the polymerase chain reaction products with BslI, a restriction enzyme specific for the site difference, gave one, two and three fragments for the two homozygotes and the heterozygote, respectively, following electrophoretic separation. This provides a DNA-based means of routine screening of the highly informative LDH-C1* polymorphism in brown trout population genetic studies. Primer sets presented could be used to sequence cDNA of other LDH* genes of brown trout and other species.

  16. 21 CFR 862.1670 - Sorbitol dehydrogenase test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sorbitol dehydrogenase test system. 862.1670... Systems § 862.1670 Sorbitol dehydrogenase test system. (a) Identification. A sorbitol dehydrogenase test system is a device intended to measure the activity of the enzyme sorbitol dehydrogenase in serum...

  17. Enhancement of L-3-hydroxybutyryl-CoA dehydrogenase activity and circulating ketone body levels by pantethine. Relevance to dopaminergic injury.

    PubMed

    Cornille, Emilie; Abou-Hamdan, Mhamad; Khrestchatisky, Michel; Nieoullon, André; de Reggi, Max; Gharib, Bouchra

    2010-04-23

    The administration of the ketone bodies hydroxybutyrate and acetoacetate is known to exert a protective effect against metabolic disorders associated with cerebral pathologies. This suggests that the enhancement of their endogenous production might be a rational therapeutic approach. Ketone bodies are generated by fatty acid beta-oxidation, a process involving a mitochondrial oxido-reductase superfamily, with fatty acid-CoA thioesters as substrates. In this report, emphasis is on the penultimate step of the process, i.e. L-3-hydroxybutyryl-CoA dehydrogenase activity. We determined changes in enzyme activity and in circulating ketone body levels in the MPTP mouse model of Parkinson's disease. Since the active moiety of CoA is pantetheine, mice were treated with pantethine, its naturally-occurring form. Pantethine has the advantage of being known as an anti-inflammatory and hypolipidemic agent with very few side effects. We found that dehydrogenase activity and circulating ketone body levels were drastically reduced by the neurotoxin MPTP, whereas treatment with pantethine overcame these adverse effects. Pantethine prevented dopaminergic neuron loss and motility disorders. In vivo and in vitro experiments showed that the protection was associated with enhancement of glutathione (GSH) production as well as restoration of respiratory chain complex I activity and mitochondrial ATP levels. Remarkably, pantethine treatment boosted the circulating ketone body levels in MPTP-intoxicated mice, but not in normal animals. These finding demonstrate the feasibility of the enhancement of endogenous ketone body production and provide a promising therapeutic approach to Parkinson's disease as well as, conceivably, to other neurodegenerative disorders.

  18. [Enzyme activity in the subcellular fractions of the liver of rats following a flight on board the Kosmos-1129 biosatellite].

    PubMed

    Tigranian, R A; Vetrova, E G; Abraham, S; Lin, C; Klein, H

    1983-01-01

    The activities of malate, isocitrate, and lactate dehydrogenases were measured in the liver mitochondrial and cytoplasmatic fractions of rats flown for 18.5 days onboard Cosmos-1129. The activities of the oxidative enzymes, malate and isocitrate dehydrogenases, in the mitochondrial fraction and those of the glycolytic enzyme, lactate dehydrogenase, in the cytoplasmatic fraction were found to decrease.

  19. A Review of Worksite Lactation Accommodations.

    PubMed

    Hilliard, Elizabeth Dianne

    2017-01-01

    The purpose of this review was to examine workplace lactation accommodations, and their association with breastfeeding duration, and identify strategies occupational health professionals can use to promote lactation improvements. This study included literature published from 1985 through 2015 and listed in PubMed and CINAHL. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 11 articles were identified for review. Presence of a corporate lactation program, on-site child care, and return to work/telephone lactation consultation were consistently associated with breastfeeding at 6 months. Other breastfeeding accommodations (i.e., lactation spaces, lactation breaks, worksite lactation policies, and supervisor/coworker support) were not consistently associated with breastfeeding duration. Occupational health professionals can play key roles in improving the effectiveness of lactation accommodations. Assuring adequate implementation of accommodations, increasing communication and marketing of accommodations, and promoting supervisor and coworker support are areas that occupational health professionals should explore for improving lactation duration.

  20. Metabolic organization and effects of feeding on enzyme activities of the dogfish shark (Squalus acanthias) rectal gland.

    PubMed

    Walsh, Patrick J; Kajimura, Makiko; Mommsen, Thomas P; Wood, Chris M

    2006-08-01

    In order to investigate the metabolic poise of the elasmobranch rectal gland, we conducted two lines of experimentation. First, we examined the effects of feeding on plasma metabolites and enzyme activities from several metabolic pathways in several tissues of the dogfish shark, Squalus acanthias, after starvation and at 6, 20, 30 and 48 h post-feeding. We found a rapid and sustained ten-fold decrease in plasma beta-hydroxybutyrate at 6 h and beyond compared with starved dogfish, suggesting an upregulation in the use of this substrate, a decrease in production, or both. Plasma acetoacetate levels remain unchanged, whereas there was a slight and transient decrease in plasma glucose levels at 6 h. Several enzymes showed a large increase in activity post-feeding, including beta-hydroxybutyrate dehydrogenase in rectal gland and liver, and in rectal gland, isocitrate dehydrogenase, citrate synthase, lactate dehydrogenase, aspartate amino transferase, alanine amino transferase, glutamine synthetase and Na(+)/K(+) ATPase. Also notable in these enzyme measurements was the overall high level of activity in the rectal gland in general. For example, activity of the Krebs' TCA cycle enzyme citrate synthase (over 30 U g(-1)) was similar to activities in muscle from other species of highly active fish. Surprisingly, lactate dehydrogenase activity in the gland was also high (over 150 U g(-1)), suggesting either an ability to produce lactate anaerobically or use lactate as an aerobic fuel. Given these interesting observations, in the second aspect of the study we examined the ability of several metabolic substrates (alone and in combination) to support chloride secretion by the rectal gland. Among the substrates tested at physiological concentrations (glucose, beta-hydroxybutyrate, lactate, alanine, acetoacetate, and glutamate), only glucose could consistently maintain a viable preparation. Whereas beta-hydroxybutyrate could enhance gland activity when presented in combination

  1. Relative significances of pH and substrate starch level to roles of Streptococcus bovis S1 in rumen acidosis.

    PubMed

    Chen, Lianmin; Liu, Shimin; Wang, Hongrong; Wang, Mengzhi; Yu, Lihuai

    2016-12-01

    To clarify the relative importance of pH and substrate starch level in fermentation characteristics and regulatory mechanism of Streptococcus bovis S1 in rumen acidosis, an in vitro fermentation of three levels of soluble starch (1, 3 and 9 g/L) was established with pH in the media were maintained constant at 5.5 or 6.5. The results showed that the dominant product of S. bovis S1 was lactate at both pH, the production depended on the starch level, and more lactate was produced at pH 6.5 than that at pH 5.5 (P < 0.001). At pH 5.5, the activity of lactate dehydrogenase (LDH) and α-amylase (α-AMY), their abundances, the relative expressions of LDH, PFL (gene encoding pyruvate formate-lyase), CCPA (gene encoding global catabolite control protein A) and α-AMY genes were higher than those at pH 6.5 (P < 0.05), whereas the concentration of fructose-1,6-diphosphate (FDP) was lower. The activity of LDH, α-AMY and FDP, and the relative expressions of LDH, PFL, CCPA and α-AMY genes were, in general, positively related to the starch level. The canonical regression analysis indicated that the pH had more profound effect compared with the starch level, in terms of the acid productions, enzyme activity and gene expressions. It was concluded that the fermentation of S. bovis was regulated at the transcription level in response to both pH and substrate starch concentration, but more sensitive to pH changes.

  2. High levels of anti-inflammatory and pro-resolving lipid mediators lipoxins and resolvins and declining docosahexaenoic acid levels in human milk during the first month of lactation

    PubMed Central

    2013-01-01

    Background The fatty acid mixture of human milk is ideal for the newborn but little is known about its composition in the first few weeks of lactation. Of special interest are the levels of long-chain PUFAs (LCPUFAs), since these are essential for the newborn’s development. Additionally, the LCPUFAs arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are precursors for lipid mediators which regulate inflammation. Methods We determined the composition of 94 human milk samples from 30 mothers over the first month of lactation for fatty acids using GC-MS and quantified lipid mediators using HPLC-MS/MS. Results Over the four weeks period, DHA levels decreased, while levels of γC18:3 and αC18:3 steadily increased. Intriguingly, we found high concentrations of lipid mediators and their hydroxy fatty acid precursors in human milk, including pro-inflammatory leukotriene B4 (LTB4) and anti-inflammatory and pro-resolving lipoxin A4 (LXA4), resolvin D1 (RvD1) and resolvin E1 (RvE1). Lipid mediator levels were stable with the exception of two direct precursors. Conclusions Elevated levels of DHA right after birth might represent higher requirements of the newborn and the high content of anti-inflammatory and pro-resolving lipid mediators and their precursors may indicate their role in neonatal immunity and may be one of the reasons for the advantage of human milk over infant formula. PMID:23767972

  3. Effect of zinc supplementation on lipid peroxidation and lactate levels in rats with diabetes induced by streptozotocin and subjected to acute swimming exercise.

    PubMed

    Bicer, M; Gunay, M; Baltaci, A K; Uney, K; Mogulkoc, R; Akil, M

    2012-01-01

    The present study aims to explore the effect of zinc supplementation on lipid peroxidation and lactate levels in rats having diabetes induced by streptozotocin and subjected to acute swimming exercise. A total of 80 adult male rats of Sprague-Dawley type were equally allocated to 8 groups: Group 1, general control. Group 2, zinc-supplemented group. Group 3, zinc-supplemented, diabetic group. Group 4, swimming control group. Group 5, zinc-supplemented swimming group. Group 6, zinc-supplemented diabetic swimming group. Group 7, diabetic swimming group. Group 8, diabetic group. At the end of the 4-week study, blood samples were collected to determine MDA, GSH, GPx, SOD, lactate and zinc levels. The highest MDA values were found in group 7 and 8 (p<0.001). GSH values in groups 5 and 6 were higher (p<0.001). The highest GPx values were established in groups 2, 5 and 6 (p<0.001). SOD values were the highest in groups 5 and 6 (p<0.001) and lowest in groups 2, 3 and 8 (p<0.001). The highest plasma lactate levels were found in group 7 (p<0.001). The highest zinc levels were obtained in groups 1, 2 and 5 (p<0.001), and the lowest zinc levels were found in groups 7 and 8 (p<0.001). Results of the study reveal that zinc supplementation prevents the increase of free radical formation, suppression of antioxidant activity and muscle exhaustion, all of which result from diabetes and acute exercise. Zinc supplementation may contribute to health performance in diabetes and acute exercise (Tab. 2, Fig. 1 Ref. 47). Full Text in PDF www.elis.sk.

  4. Lactate and the Lactate-to-Pyruvate Molar Ratio Cannot Be Used as Independent Biomarkers for Monitoring Brain Energetic Metabolism: A Microdialysis Study in Patients with Traumatic Brain Injuries

    PubMed Central

    Sahuquillo, Juan; Merino, Maria-Angels; Sánchez-Guerrero, Angela; Arikan, Fuat; Vidal-Jorge, Marian; Martínez-Valverde, Tamara; Rey, Anna; Riveiro, Marilyn; Poca, Maria-Antonia

    2014-01-01

    Background For decades, lactate has been considered an excellent biomarker for oxygen limitation and therefore of organ ischemia. The aim of the present study was to evaluate the frequency of increased brain lactate levels and the LP ratio (LPR) in a cohort of patients with severe or moderate traumatic brain injury (TBI) subjected to brain microdialysis monitoring to analyze the agreement between these two biomarkers and to indicate brain energy metabolism dysfunction. Methods Forty-six patients with an admission Glasgow coma scale score of ≤13 after resuscitation admitted to a dedicated 10-bed Neurotraumatology Intensive Care Unit were included, and 5305 verified samples of good microdialysis data were analyzed. Results Lactate levels were above 2.5 mmol/L in 56.9% of the samples. The relationships between lactate and the LPR could not be adequately modeled by any linear or non-linear model. Neither Cohen’s kappa nor Gwet’s statistic showed an acceptable agreement between both biomarkers to classify the samples in regard to normal or abnormal metabolism. The dataset was divided into four patterns defined by the lactate concentrations and the LPR. A potential interpretation for these patterns is suggested and discussed. Pattern 4 (low pyruvate levels) was found in 10.7% of the samples and was characterized by a significantly low concentration of brain glucose compared with the other groups. Conclusions Our study shows that metabolic abnormalities are frequent in the macroscopically normal brain in patients with traumatic brain injuries and a very poor agreement between lactate and the LPR when classifying metabolism. The concentration of lactate in the dialysates must be interpreted while taking into consideration the LPR to distinguish between anaerobic metabolism and aerobic hyperglycolysis. PMID:25025772

  5. Stable shRNA Silencing of Lactate Dehydrogenase A (LDHA) in Human MDA-MB-231 Breast Cancer Cells Fails to Alter Lactic Acid Production, Glycolytic Activity, ATP or Survival.

    PubMed

    Mack, Nzinga; Mazzio, Elizabeth A; Bauer, David; Flores-Rozas, Hernan; Soliman, Karam F A

    2017-03-01

    In the US, African Americans have a high death rate from triple-negative breast cancer (TNBC), characterized by lack of hormone receptors (ER, PR, HER2/ERRB2) which are otherwise valuable targets of chemotherapy. There is a need to identify novel targets that negatively impact TNBC tumorigenesis. TNBCs release an abundance of lactic acid, under normoxic, hypoxic and hyperoxic conditions; this referred to as the Warburg effect. Accumulated lactic acid sustains peri-cellular acidity which propels metastatic invasion and malignant aggressive transformation. The source of lactic acid is believed to be via conversion of pyruvate by lactate dehydrogenase (LDH) in the last step of glycolysis, with most studies focusing on the LDHA isoform. In this study, LDHA was silenced using long-term MISSION® shRNA lentivirus in human breast cancer MDA-MB-231 cells. Down-regulation of LDHA transcription and protein expression was confirmed by western blot, immunocytochemistry and qPCR. A number of parameters were measured in fully viable vector controls versus knock-down (KD) clones, including levels of lactic acid produced, glucose consumed, ATP and basic metabolic rates. The data show that lentivirus V-165 generated a knock-down clone most effective in reducing both gene and protein levels to less than 1% of vector controls. Stable KD showed absolutely no changes in cell viability, lactic acid production, ATP, glucose consumption or basic metabolic rate. Given the complete absence of impact on any observed parameter by LDH-A KD and this being somewhat contrary to findings in the literature, further analysis was required to determine why. Whole-transcriptome analytic profile on MDA-MB-231 for LDH subtypes using Agilent Human Genome 4×44k microarrays, where the data show the following component breakdown. Transcripts: 30.47 % LDHA, 69.36% LDHB, 0.12% LDHC and 0.05% LDHD. These findings underscore the importance of alternative isoforms of LDH in cancer cells to produce lactic acid

  6. Enhancement of Astroglial Aerobic Glycolysis by Extracellular Lactate-Mediated Increase in cAMP

    PubMed Central

    Vardjan, Nina; Chowdhury, Helena H.; Horvat, Anemari; Velebit, Jelena; Malnar, Maja; Muhič, Marko; Kreft, Marko; Krivec, Špela G.; Bobnar, Saša T.; Miš, Katarina; Pirkmajer, Sergej; Offermanns, Stefan; Henriksen, Gjermund; Storm-Mathisen, Jon; Bergersen, Linda H.; Zorec, Robert

    2018-01-01

    Besides being a neuronal fuel, L-lactate is also a signal in the brain. Whether extracellular L-lactate affects brain metabolism, in particular astrocytes, abundant neuroglial cells, which produce L-lactate in aerobic glycolysis, is unclear. Recent studies suggested that astrocytes express low levels of the L-lactate GPR81 receptor (EC50 ≈ 5 mM) that is in fat cells part of an autocrine loop, in which the Gi-protein mediates reduction of cytosolic cyclic adenosine monophosphate (cAMP). To study whether a similar signaling loop is present in astrocytes, affecting aerobic glycolysis, we measured the cytosolic levels of cAMP, D-glucose and L-lactate in single astrocytes using fluorescence resonance energy transfer (FRET)-based nanosensors. In contrast to the situation in fat cells, stimulation by extracellular L-lactate and the selective GPR81 agonists, 3-chloro-5-hydroxybenzoic acid (3Cl-5OH-BA) or 4-methyl-N-(5-(2-(4-methylpiperazin-1-yl)-2-oxoethyl)-4-(2-thienyl)-1,3-thiazol-2-yl)cyclohexanecarboxamide (Compound 2), like adrenergic stimulation, elevated intracellular cAMP and L-lactate in astrocytes, which was reduced by the inhibition of adenylate cyclase. Surprisingly, 3Cl-5OH-BA and Compound 2 increased cytosolic cAMP also in GPR81-knock out astrocytes, indicating that the effect is GPR81-independent and mediated by a novel, yet unidentified, excitatory L-lactate receptor-like mechanism in astrocytes that enhances aerobic glycolysis and L-lactate production via a positive feedback mechanism. PMID:29867342

  7. Enzymatic characterization of a novel bovine liver dihydrodiol dehydrogenase--reaction mechanism and bile acid dehydrogenase activity.

    PubMed

    Nanjo, H; Adachi, H; Morihana, S; Mizoguchi, T; Nishihara, T; Terada, T

    1995-05-11

    Bovine liver cytosolic dihydrodiol dehydrogenase (DD3) has been characterized by its unique dihydrodiol dehydrogenase activity for trans-benzenedihydrodiol (trans-1,2-dihydrobenzene-1,2-diol) with the highest affinity and the greatest velocity among three multiple forms of dihydrodiol dehydrogenases (DD1-DD3). It is the first time that DD3 has shown a significant dehydrogenase activity for (S)-(+)-1-indanol with low Km value (0.33 +/- 0.022 mM) and high K(cat) value (25 +/- 0.79 min-1). The investigation of the product inhibition of (S)-(+)-1-indanol with NADP+ versus 1-indanone and NADPH clearly showed that the enzymatic reaction of DD3 may follow a typical ordered Bi Bi mechanism similar to many aldo/keto reductases. Additionally, DD3 was shown to catalyze the dehydrogenation of bile acids (lithocholic acid, taurolithocholic acid and taurochenodeoxycholic acid) having no 12-hydroxy groups with low Km values (17 +/- 0.65, 33 +/- 1.9 and 890 +/- 73 microM, respectively). In contrast, DD1, 3 alpha-hydroxysteroid dehydrogenase, shows a broad substrate specificity for many bile acids with higher affinity than those of DD3. Competitive inhibition of DD3 with androsterone against dehydrogenase activity for (S)-(+)-1-indanol, trans-benzenedihydrodiol or lithocholic acid suggests that these three substrates bind to the same substrate binding site of DD3, different from the case of human liver bile acid binder/dihydrodiol dehydrogenase (Takikawa, H., Stolz, A., Sugiyama, Y., Yoshida, H., Yamamoto, M. and Kaplowitz, N. (1990) J. Biol. Chem. 265, 2132-2136). Considering the reaction mechanism, DD3 may also play an important role in bile acids metabolism as well as the detoxication of aromatic hydrocarbons.

  8. Differences in the ribosomes prepared from lactating and non-lactating bovine mammary gland

    PubMed Central

    Herrington, M. D.; Hawtrey, A. O.

    1971-01-01

    1. Ribosomes prepared from bovine lactating mammary gland are able to synthesize protein, whereas similar preparations from non-lactating glands are not. Washing the ribosome suspensions through a medium containing 0.5m-ammonium chloride enhanced their ability to incorporate phenylalanine into polyphenylalanine. 2. Ribosomes isolated from non-lactating bovine mammary gland, in contrast with those from rat liver and lactating mammary gland, contained significant amounts of extraneous nucleases. These enzymes could be removed by washing with a medium A buffer containing 0.5m-ammonium chloride. 3. Only those ribosomes from functionally active tissues were able to bind polyuridylic acid and phenylalanyl-tRNA. PMID:5165653

  9. A Lactate Kinetics Method for Assessing the Maximal Lactate Steady State Workload

    PubMed Central

    Hering, Gernot O.; Hennig, Ewald M.; Riehle, Hartmut J.; Stepan, Jens

    2018-01-01

    During a continuously increasing exercise workload (WL) a point will be reached at which arterial lactate accumulates rapidly. This so-called lactate threshold (LT) is associated with the maximal lactate steady state workload (MLSSW), the highest WL, at which arterial lactate concentration [LA] does not change. However, the physiological range in which the LT and the MLSSW occur has not been demonstrated directly. We used minor WL variations in the MLSSW range to assess arterial lactate kinetics in 278 treadmill and 148 bicycle ergometer exercise tests. At a certain workload, minimal further increment of running speed (0.1–0.15 m/s) or cycling power (7–10 W) caused a steep elevation of [LA] (0.9 ± 0.43 mM, maximum increase 2.4 mM), indicating LT achievement. This sharp [LA] increase was more pronounced when higher WL increments were used (0.1 vs. 0.30 m/s, P = 0.02; 0.15 vs. 0.30 m/s, P < 0.001; 7 vs. 15 W, P = 0.002; 10 vs. 15 W, P = 0.001). A subsequent workload reduction (0.1 m/s/7 W) stopped the [LA] increase indicating MLSSW realization. LT based determination of running speed (MLSSW) was highly reproducible on a day-to-day basis (r = 0.996, P < 0.001), valid in a 10 km constant velocity setting (r = 0.981, P < 0.001) and a half marathon race (r = 0.969, P < 0.001). These results demonstrate a fine-tuned regulation of exercise-related lactate metabolism, which can be reliably captured by assessing lactate kinetics at the MLSSW. PMID:29651253

  10. Purification of acetaldehyde dehydrogenase and alcohol dehydrogenases from Thermoanaerobacter ethanolicus 39E and characterization of the secondary-alcohol dehydrogenase (2 degrees Adh) as a bifunctional alcohol dehydrogenase--acetyl-CoA reductive thioesterase.

    PubMed Central

    Burdette, D; Zeikus, J G

    1994-01-01

    The purification and characterization of three enzymes involved in ethanol formation from acetyl-CoA in Thermoanaerobacter ethanolicus 39E (formerly Clostridium thermohydrosulfuricum 39E) is described. The secondary-alcohol dehydrogenase (2 degrees Adh) was determined to be a homotetramer of 40 kDa subunits (SDS/PAGE) with a molecular mass of 160 kDa. The 2 degrees Adh had a lower catalytic efficiency for the oxidation of 1 degree alcohols, including ethanol, than for the oxidation of secondary (2 degrees) alcohols or the reduction of ketones or aldehydes. This enzyme possesses a significant acetyl-CoA reductive thioesterase activity as determined by NADPH oxidation, thiol formation and ethanol production. The primary-alcohol dehydrogenase (1 degree Adh) was determined to be a homotetramer of 41.5 kDa (SDS/PAGE) subunits with a molecular mass of 170 kDa. The 1 degree Adh used both NAD(H) and NADP(H) and displayed higher catalytic efficiencies for NADP(+)-dependent ethanol oxidation and NADH-dependent acetaldehyde (identical to ethanal) reduction than for NADPH-dependent acetaldehyde reduction or NAD(+)-dependent ethanol oxidation. The NAD(H)-linked acetaldehyde dehydrogenase was a homotetramer (360 kDa) of identical subunits (100 kDa) that readily catalysed thioester cleavage and condensation. The 1 degree Adh was expressed at 5-20% of the level of the 2 degrees Adh throughout the growth cycle on glucose. The results suggest that the 2 degrees Adh primarily functions in ethanol production from acetyl-CoA and acetaldehyde, whereas the 1 degree Adh functions in ethanol consumption for nicotinamide-cofactor recycling. Images Figure 1 PMID:8068002

  11. Dopamine-regulated adrenocorticotropic hormone secretion in lactating rats: functional plasticity of melanotropes.

    PubMed

    Oláh, Márk; Fehér, Pálma; Ihm, Zsófia; Bácskay, Ildikó; Kiss, Timea; Freeman, Marc E; Nagy, Gyorgy M; Vecsernyés, Miklós

    2009-01-01

    Pro-opiomelanocortin (POMC) is processed to adrenocorticotropic hormone (ACTH) and beta-lipotropin in corticotropes of the anterior lobe, and to alpha-melanocyte-stimulating hormone (alpha-MSH) and beta-endorphin in melanotropes of the intermediate lobe (IL) of the pituitary gland. While ACTH secretion is predominantly under the stimulatory influence of the hypothalamic factors, hormone secretion of the IL is tonically inhibited by neuroendocrine dopamine (NEDA) neurons. Lobe-specific POMC processing is not absolute. For example, D(2) type DA receptor (D2R)-deficient mice have elevated plasma ACTH levels, although it is known that corticotropes do not express D2R(s). Moreover, observations that suckling does not influence alpha-MSH release, while it induces an increase in plasma ACTH is unexplained. The aim of the present study was to investigate the involvement of the NEDA system in the regulation of ACTH secretion and the participation of the IL in ACTH production in lactating rats. Untreated and estradiol (E(2))-substituted ovariectomized (OVX) females were also studied. The concentration of ACTH in the IL was higher in lactating rats than in OVX rats, while the opposite change in alpha-MSH level of the IL was observed. DA levels in the IL and the neural lobe were lower in lactating rats than in OVX rats. Suckling-induced ACTH response was eliminated by pretreatment with the DA receptor agonist, bromocriptine (BRC). Inhibition of DA biosynthesis by alpha-methyl-p-tyrosine (alphaMpT) and blockade of D2R by domperidone (DOM) elevated plasma ACTH levels, but did not influence plasma alpha-MSH levels in lactating rats. The same drugs had opposite effects in OVX and OVX + E(2) animals. In lactating mothers, BRC was able to block ACTH responses induced by both alphaMpT and DOM. Surgical denervation of the IL elevated basal plasma levels of ACTH. Taken together, these data indicate that melanotropes synthesize ACTH during lactation and its release from these cells is

  12. Dopamine-Regulated Adrenocorticotropic Hormone Secretion in Lactating Rats: Functional Plasticity of Melanotropes

    PubMed Central

    Oláh, Márk; Fehér, Pálma; Ihm, Zsófia; Bácskay, Ildikó; Kiss, Timea; Freeman, Marc E.; Nagy, György M.; Vecsernyés, Miklós

    2009-01-01

    Pro-opiomelanocortin (POMC) is processed to adrenocorticotropic hormone (ACTH) and β-lipotropin in corticotropes of the anterior lobe, and to α-melanocyte-stimulating hormone (α-MSH) and β-endorphin in melanotropes of the intermediate lobe (IL) of the pituitary gland. While ACTH secretion is predominantly under the stimulatory influence of the hypothalamic factors, hormone secretion of the IL is tonically inhibited by neuroendocrine dopamine (NEDA) neurons. Lobe-specific POMC processing is not absolute. For example, D2 type DA receptor (D2R)-deficient mice have elevated plasma ACTH levels, although it is known that corticotropes do not express D2R(s). Moreover, observations that suckling does not influence α-MSH release, while it induces an increase in plasma ACTH is unexplained. The aim of the present study was to investigate the involvement of the NEDA system in the regulation of ACTH secretion and the participation of the IL in ACTH production in lactating rats. Untreated and estradiol (E2)-substituted ovariectomized (OVX) females were also studied. The concentration of ACTH in the IL was higher in lactating rats than in OVX rats, while the opposite change in α-MSH level of the IL was observed. DA levels in the IL and the neural lobe were lower in lactating rats than in OVX rats. Suckling-induced ACTH response was eliminated by pretreatment with the DA receptor agonist, bromocriptine (BRC). Inhibition of DA biosynthesis by α-methyl-p-tyrosine (αMpT) and blockade of D2R by domperidone (DOM) elevated plasma ACTH levels, but did not influence plasma α-MSH levels in lactating rats. The same drugs had opposite effects in OVX and OVX + E2 animals. In lactating mothers, BRC was able to block ACTH responses induced by both αMpT and DOM. Surgical denervation of the IL elevated basal plasma levels of ACTH. Taken together, these data indicate that melanotropes synthesize ACTH during lactation and its release from these cells is regulated by NEDA neurons. PMID

  13. Prevalence and incidence of intramammary infections in lactating dairy goats.

    PubMed

    McDougall, S; Malcolm, D; Prosser, Cg

    2014-05-01

    To determine the prevalence of intramammary infection (IMI) of lactating dairy goats between 0 and 4 days postpartum, the prevalence and incidence rate of new IMI at Weeks 2, 14 and 27 of lactation, and the relationship between herd-level prevalence of IMI and bulk tank somatic cell count (BTSCC). Milk samples were collected from 8% of a herd (total 624 does) from 18 dairy goat herds in the Waikato region of New Zealand, for bacteriology and somatic cell count (SCC) determination, from both glands within 4 days of kidding (Week 0) and again at Weeks 2, 14 and 27. Prevalence of IMI was determined at each time point and incidence rate calculated for Weeks 0-2, 2-14, and 14-27. Greenwood and Reed-Frost models were compared for estimation of the transmission parameter for all pathogens, and for Staphylococcus aureus, coagulase negative staphylococci (CNS) and Corynebacterium spp. separately. Bacteria were isolated from 1,122/4,814 (23.3%) glands, with CNS (13.4%) and Corynebacterium spp. (7.3%) being the most common isolates. Prevalence of any IMI increased with stage of lactation, varied among herds, and increased with age (all p<0.05). Incidence rate was 80, 24 and 7 new IMI/10,000 gland days for Weeks 0-2, 2-14 and 14-27, respectively. Incidence rate for any IMI increased with age and with the presence of an IMI in the contralateral gland, and varied among herds (p<0.001). The transmission of each pathogen was better modelled assuming contagiousness (Reed-Frost models), than not (Greenwood models). At gland level, IMI increased SCC at all stages of lactation (p<0.001). The gland prevalence of IMI within herds was positively associated with ln BTSCC at Week 2 (p=0.02), but not Weeks 14 or 27 (p>0.05). Prevalence of IMI increased with stage of lactation, but the highest incidence rate of new IMI occurred in early lactation. Models accounting for the contagious nature of infection fitted better than those not accounting for contagiousness. BTSCC was only associated

  14. Initial blood lactate correlates with carboxyhemoglobin and clinical severity in carbon monoxide poisoned patients.

    PubMed

    Cervellin, Gianfranco; Comelli, Ivan; Rastelli, Gianni; Picanza, Alessandra; Lippi, Giuseppe

    2014-12-01

    The aim of this study was to assess the role of blood lactate levels at admission in carbon monoxide (CO)-poisoned patients for establishing severity of poisoning and short term prognosis. All cases of CO poisoning visited in the emergency department during the years 2012 and 2013 were retrieved from the hospital database. The concentration of COHb and lactate was assessed in arterial blood in all patients with suspected CO poisoning, along with the plasma concentration of troponin I (TnI). The control population for TnI results consisted in 125 blood donors. Twenty three (61%) out of 38 CO-poisoned patients underwent hyperbaric oxygen (HBO) treatment, and 10 (26%) were admitted to a hospital ward. A significant correlation was found between lactate and COHb (r=0.54; p<0.001), and between lactate and TnI (r=0.44; p=0.001). A significant correlation was also found between COHb and TnI (r=0.38; p=0.020). Blood lactate levels were higher in patients treated with HBO and hospital admission. In multivariate analysis, none of the parameters was associated with HBO treatment, whereas increased value of blood lactate (p=0.036) was the only significant predictor of hospital admission. Twenty five (66%) patients had detectable TnI levels compared to 13% controls (p<0.001), whereas 16% CO-poisoned patients had TnI levels >99th percentile compared to 2% controls (p=0.003). The odds ratio for detectable TnI and TnI >99th percentile in CO-poisoned patients were 13.1 (p<0.001) and 7.6 (p=0.006), respectively. Initial blood lactate level may be useful for risk stratification of CO-poisoned patients, especially for predicting hospitalization. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Influence of lactation and pregnancy + lactation on mechanical properties and mineral content of the rat femur.

    PubMed

    Peng, T C; Kusy, R P; Garner, S C; Hirsch, P F; De Blanco, M C

    1987-06-01

    The quality of bone was assessed from femurs of rats both during lactation and after pregnancy + lactation. Mechanical properties of stiffness, strength, toughness, and ductility were measured, along with standard measurements of dry weight, ash weight, and total bone mineral. No changes occurred during the first week of lactation. During the second and third weeks of lactation all bone parameters except ductility decreased significantly. These data are consistent with bone losing mineral in order to supplement the dietary calcium intake necessary for milk production. In other experiments, femurs were collected from nulliparous rats and from rats that had previously undergone 1-3 pregnancy + lactations. The largest changes in bone mineral and mechanical properties occurred after a single pregnancy + lactation period, although significant further decreases in stiffness and strength occurred after the second pregnancy + lactation. No additional losses occurred following the third pregnancy + lactation. Even 5 months after only one pregnancy + lactation period, the bone quality was still impaired as all bone properties were lower than in nulliparous controls. Because the changes, especially stiffness and strength, were relatively larger than the changes in dry and ash weights of bone, measurements of these mechanical properties provide a more sensitive method to evaluate the quality of bone.

  16. Influence of oxygen therapy on glucose-lactate metabolism after diffuse brain injury.

    PubMed

    Reinert, Michael; Schaller, Benoit; Widmer, Hans Rudolf; Seiler, Rolf; Bullock, Ross

    2004-08-01

    Severe traumatic brain injury (TBI) imposes a huge metabolic load on brain tissue, which can be summarized initially as a state of hypermetabolism and hyperglycolysis. In experiments O2 consumption has been shown to increase early after trauma, especially in the presence of high lactate levels and forced O2 availability. In recent clinical studies the effect of increasing O2 availability on brain metabolism has been analyzed. By their nature, however, clinical trauma models suffer from a heterogeneous injury distribution. The aim of this study was to analyze, in a standardized diffuse brain injury model, the effect of increasing the fraction of inspired O2 on brain glucose and lactate levels, and to compare this effect with the metabolism of the noninjured sham-operated brain. A diffuse severe TBI model developed by Foda and Maramarou, et al., in which a 420-g weight is dropped from a height of 2 m was used in this study. Forty-one male Wistar rats each weighing approximately 300 g were included. Anesthesized rats were monitored by placing a femoral arterial line for blood pressure and blood was drawn for a blood gas analysis. Two time periods were defined: Period A was defined as preinjury and Period B as postinjury. During Period B two levels of fraction of inspired oxygen (FiO2) were studied: air (FiO2 0.21) and oxygen (FiO2 1). Four groups were studied including sham-operated animals: air-air-sham (AAS); air-O2-sham (AOS); air-air-trauma (AAT); and air-O2-trauma (AOT). In six rats the effect of increasing the FiO2 on serum glucose and lactate was analyzed. During Period B lactate values in the brain determined using microdialysis were significantly lower (p < 0.05) in the AOT group than in the AAT group and glucose values in the brain determined using microdialysis were significantly higher (p < 0.04). No differences were demonstrated in the other groups. Increasing the FiO2 had no significant effect on the serum levels of glucose and lactate. Increasing the Fi

  17. Comparison of medetomidine and fentanyl-droperidol in dogs: sedation, analgesia, arterial blood gases and lactate levels.

    PubMed Central

    Pettifer, G R; Dyson, D H

    1993-01-01

    Medetomidine and fentanyl-droperidol (Innovar-vet) were assessed over a three hour period in 80 healthy dogs. Following physical examination, electrocardiogram (ECG), arterial blood sample analysis, and dynamometer pressure threshold (analgesia score), the dogs were randomly assigned to one of four treatments: Miv--medetomidine (750 micrograms/M2) administered intravenously (IV), Mim--medetomidine (1000 micrograms/M2) administered intramuscularly (IM), Iiv--Innovar-vet IV (0.05 mL/kg) or Iim--Innovar-vet IM (0.1 mL/kg). All assessments were carried out by a single individual unaware of the treatment used. Objective assessments included temperature, heart and respiratory rates, analgesia score, arterial blood gases, acid-base and lactate levels. Subjective evaluation included degree of sedation, response to various clinical procedures, noise responsiveness, posture, and the incidence of side effects. Onset and duration of effect were also recorded. The ECG strips were assessed for arrhythmias. Data was analyzed using a 3-way analysis of variance for continuous variables and a Chi-square analysis of frequencies. A p value < or = 0.05 was considered significant. Medetomidine-treated animals had a decreased respiratory rate, longer duration of analgesic effect, increased incidence of bradycardia, vomiting and twitching, were less noise responsive and shivered less throughout the study. An increased incidence of second degree heart block with Miv (15 min), a delayed onset and recovery with Mim and increased lactate levels following Iiv (15 min) were observed. No differences were found in other measurements and good to excellent chemical restraint was produced with all treatments in 65% or more cases. Images Fig. 1. PMID:8490814

  18. Lead and PCB's in canvasback ducks: Relationship between enzyme levels and residues in blood

    USGS Publications Warehouse

    Dieter, M.P.; Perry, M.C.; Mulhern, B.M.

    1976-01-01

    Blood samples were taken for two successive years from canvasback ducks trapped in the Chesapeake Bay. The first winter (1972?1973) five plasma enzymes known to respond to organochlorine poisoning were examined. Abnormal enzyme elevations suggested that 20% of the population sampled (23/115 ducks) might contain organochlorine contaminants, but no residue analyses were performed. The second winter (1974) two of the same enzymes, aspartate aminotransferase and lactate dehydrogenase, and a third enzyme known to be specifically inhibited by lead, delta-aminolevulinic acid dehydratase, were assayed in 95 blood samples. Blood residues of organochlorine compounds and of lead were determined in representative samples, and the correlations between residue levels and enzyme changes were examined. The enzyme bioassays in 1974 indicated that lead was a more prevalent environmental contaminant than organochlorine compounds in canvasback ducks; 17% of the blood samples had less than one-half of the normal delta-aminolevulinic acid dehydratase activity, but only 11% exhibited abnormal aspartate aminotransferase or lactate dehydrogenase activities. These findings were confirmed by residue analyses that demonstrated lead concentrations four times higher than background levels, but only relatively low organochlorine concentrations. There was a highly significant inverse correlation between delta-aminolevulinic acid dehydratase activity and blood lead concentrations (P<0.01), and a weaker but significant correlation between plasma aspartate aminotransferase activity and blood PCB concentrations (P<0.05). It was apparent that delta-aminolevulinic acid dehydratase activity in the blood provided a sensitive and precise estimate of lead contamination in waterfowl. In canvasback ducks 200 ppb of lead in the blood caused a 75% decrease in delta-aminolevulinic acid dehydratase activity, a magnitude of enzyme inhibition that disturbs heme synthesis and is regarded as detrimental in humans.

  19. The effect of lactation length on greenhouse gas emissions from the national dairy herd.

    PubMed

    Wall, E; Coffey, M P; Pollott, G E

    2012-11-01

    Many governments have signed up to greenhouse gas emission (GHGE) reduction programmes under their national climate change obligations. Recently, it has been suggested that the use of extended lactations in dairy herds could result in reduced GHGE. Dairy GHGE were modelled on a national basis and the model was used to compare emissions from lactations of three different lengths (305, 370 and 440 days), and a current 'base' scenario on the basis of maintaining current milk production levels. In addition to comparing GHGE from the average 'National Herd' under these scenarios, results were used to investigate how accounting for lactations of different lengths might alter the estimation of emissions calculated from the National Inventory methodology currently recommended by Intergovernmental Panel on Climate Change. Data for the three lactation length scenarios were derived from nationally recorded dairy performance information and used in the GHGE model. Long lactations required fewer milking cows and replacements to maintain current milk yield levels than short ones, but GHGEs were found to rise from 1214 t of CO2 equivalent (CE)/farm per year for lactations of 305 days to 1371 t CE/farm per year for 440-day lactations. This apparent anomaly can be explained by the less efficient milk production (kg milk produced per kg cow weight) found in later lactation, a more pronounced effect in longer lactations. The sensitivity of the model to changes in replacement rate, persistency and level of milk yield was investigated. Changes in the replacement rate from 25% to 20% and in persistency by −10% to +20% resulted in very small changes in GHGE. Differences in GHGE due to the level of milk yield were much more dramatic with animals in the top 10% for yield, producing about 25% less GHGE/year than the average animal. National Inventory results were investigated using a more realistic spread of lactation lengths than recommended for such calculations using emissions

  20. Relationship among blood indicators of lipomobilization and hepatic function during early lactation in high-yielding dairy cows.

    PubMed

    González, Felix Diaz; Muiño, Rodrigo; Pereira, Víctor; Campos, Rómulo; Benedito, José Luis

    2011-09-01

    Blood indicators are used as a tool to diagnose metabolic disorders. The present work was conducted to study the relationships among blood indicators of lipomobilization and hepatic function in high-yielding dairy cows. Two groups of Holstein cows were studied: 27 early lactation cows and 14 mid lactation cows from four different herds with similar husbandry characteristics in Galicia, Spain. Blood samples were obtained to measure beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), triglycerides (TG), and the activity of aspartate transaminase (AST) and gamma-glutamyl transferase. Cows in early lactation had higher levels of BHB and NEFA than mid lactation cows. High lipomobilization (NEFA > 400 µmol/L) was detected in 67% and 7% of early lactation and mid lactation cows, respectively, while subclinical ketosis (BHB > 1.2 mmol/L) was detected in 41% and 28% of the early lactation and lactation cows, respectively. TG concentrations were low in all cows suffering subclinical ketosis and in 61% of the cows with high lipomobilization. During early lactation, 30% of cows suffered hepatic lipidosis as detected by levels of AST. Compromised hepatic function was observed in early lactation cows as shown by lower concentrations of glucose, total protein, and urea.

  1. Arterial cord blood lactate at birth correlates with duration of pushing efforts.

    PubMed

    Dessolle, Lionel; Lebrec, Jeremie; Daraï, Emile

    2010-01-01

    To evaluate the impact of the duration of pushing efforts on arterial cord blood lactate values. This was a prospective observational study of 124 consecutive normal vaginal deliveries in a tertiary teaching hospital. Arterial cord blood lactate was determined immediately at birth with a test strip method. Univariate and multivariate analyses were performed to check for clinical determinants of lactate levels. The main measure was lactate according to the duration of pushing efforts. Arterial cord lactates increased significantly and were strongly correlated with the duration of pushing efforts, independent of gestational age and birthweight. Women pushing for more than 20 min had higher arterial cord blood lactates (4.9 +/- 1.4 vs. 3.3 +/- 1.16 mM, respectively) and a higher rate of lactates >6 mM (18 vs. 3%) than those pushing for less than 20 min. At normal delivery, arterial cord blood lactates increase significantly with the duration of pushing efforts. Pushing for more than 20 min is associated with an increased risk of metabolic acidosis in the neonate. Further studies are required to evaluate the clinical significance of these observations. 2009 S. Karger AG, Basel.

  2. Effects of supplementation and stage of lactation on performance of grazing dairy ewes.

    PubMed

    Mikolayunas, C M; Thomas, D L; Albrecht, K A; Combs, D K; Berger, Y M; Eckerman, S R

    2008-04-01

    The majority of dairy sheep in the world are fed pasture and supplemental grain during lactation; however, no trials have reported the effects of supplementation of dairy ewes grazing improved pastures in North America. In trial 1, 56 three-year-old grazing dairy ewes in early [21 +/- 10 d in milk (DIM)] or late (136 +/- 9 DIM) lactation were fed 0 or 0.82 kg of dry matter/d per ewe of supplement (16.5% crude protein mixture of corn and a soybean meal-based high-protein pellet) in a 2 x 2 factorial arrangement of treatments. There were no significant interactions between stage of lactation and supplementation treatments. Average test-day milk production was higher in early-lactation ewes than in late-lactation ewes (1.74 vs. 1.21 kg/d, respectively). Although test-day milk protein percentage was higher in late-lactation ewes than in early-lactation ewes (5.02 vs. 4.86%, respectively), there was no difference in milk fat percentage between stages of lactation. Supplemented ewes had higher milk production (1.59 vs. 1.36 kg/d, respectively), lower milk fat percentage (5.75 vs. 6.00%, respectively), and lower milk protein percentage (4.84 vs. 5.04%, respectively) than unsupplemented ewes. Milk urea N levels were similar between the 2 stages of lactation and between the 2 supplementation treatments and were above recommended levels for dairy sheep, indicating an excess intake or inefficient utilization of protein for both supplementation treatments. In trial 2, 96 two-, three-, and four-year-old grazing dairy ewes in midlactation (112 +/- 21 DIM) were randomly assigned to 4 treatments of 0, 0.41, 0.82, or 1.24 kg of dry matter/d per ewe of whole corn. Average test-day milk production increased linearly and milk fat percentage decreased quadratically with increasing amounts of corn supplementation. Milk protein yield increased linearly, and milk urea N levels decreased quadratically with increasing amounts of corn supplementation, suggesting an improvement in the

  3. Lactate: link between glycolytic and oxidative metabolism.

    PubMed

    Brooks, George A

    2007-01-01

    Once thought to be the consequence of oxygen lack in contracting skeletal muscle, the glycolytic product lactate is formed and utilised continuously under fully aerobic conditions. 'Cell-cell' and 'intracellular lactate shuttle' concepts describe the roles of lactate in delivery of oxidative and gluconeogenic substrates as well as in cell signalling. Examples of cell-cell shuttles include lactate exchanges (i) between white-glycolytic and red-oxidative fibres within a working muscle bed; (ii) between working skeletal muscle and heart; and (iii) between tissues of net lactate release and gluconeogenesis. Lactate shuttles exist in diverse tissues including in the brain, where a shuttle between astrocytes and neurons is linked to glutamatergic signalling. Because lactate, the product of glycogenolysis and glycolysis, is disposed of by oxidative metabolism, lactate shuttling unites the two major processes of cellular energy transduction. Lactate disposal is mainly through oxidation, especially during exercise when oxidation accounts for 70-75% of removal and gluconeogenesis the remainder. Lactate flux occurs down proton and concentration gradients that are established by the mitochondrial lactate oxidation complex. Marathon running is a power activity requiring high glycolytic and oxidative fluxes; such activities require lactate shuttling. Knowledge of the lactate shuttle is yet to be imparted to the sport.

  4. Change in plasma lactate concentration during arctigenin administration in a phase I clinical trial in patients with gemcitabine-refractory pancreatic cancer

    PubMed Central

    Fujioka, Rumi; Mochizuki, Nobuo; Ikeda, Masafumi; Sato, Akihiro; Nomura, Shogo; Owada, Satoshi; Yomoda, Satoshi; Tsuchihara, Katsuya; Kishino, Satoshi

    2018-01-01

    Arctigenin is evaluated for antitumor efficacy in patients with pancreatic cancer. It has an inhibitory activity on mitochondrial complex I.Therefore, plasma lactate level of patients after arctigenin administration was evaluated for biomarker of clinical response and/or adverse effect. Plasma lactate level in 15 patients enrolled in a Phase I clinical trial of GBS-01 rich in arctigenin was analyzed by colorimetric assay. Statistical analyses for association of plasma lactate and clinical responses, pharmacokinetics of arctigenin, and background factors of each patient by multivariate and univariate analyses.In about half of the patients, transient increase of lactate was observed. Correlation between plasma lactate level and pharmacokinetic parameters of arctigenin and its glucuronide conjugate, and clinical outcome was not detected. Regarding to the determinant of lactate level, only slight association with liver function test was detected. Plasma lactate level is primary determined by reutilization rather than production for antitumor effect and dose not serve as a biomarker. Arctigenin, inhibition of mitochondrial complex I, plasma lactate concentration, phase I clinical trial of GBS-01, Cori cycle. PMID:29856804

  5. Change in plasma lactate concentration during arctigenin administration in a phase I clinical trial in patients with gemcitabine-refractory pancreatic cancer.

    PubMed

    Fujioka, Rumi; Mochizuki, Nobuo; Ikeda, Masafumi; Sato, Akihiro; Nomura, Shogo; Owada, Satoshi; Yomoda, Satoshi; Tsuchihara, Katsuya; Kishino, Satoshi; Esumi, Hiroyasu

    2018-01-01

    Arctigenin is evaluated for antitumor efficacy in patients with pancreatic cancer. It has an inhibitory activity on mitochondrial complex I.Therefore, plasma lactate level of patients after arctigenin administration was evaluated for biomarker of clinical response and/or adverse effect. Plasma lactate level in 15 patients enrolled in a Phase I clinical trial of GBS-01 rich in arctigenin was analyzed by colorimetric assay. Statistical analyses for association of plasma lactate and clinical responses, pharmacokinetics of arctigenin, and background factors of each patient by multivariate and univariate analyses.In about half of the patients, transient increase of lactate was observed. Correlation between plasma lactate level and pharmacokinetic parameters of arctigenin and its glucuronide conjugate, and clinical outcome was not detected. Regarding to the determinant of lactate level, only slight association with liver function test was detected. Plasma lactate level is primary determined by reutilization rather than production for antitumor effect and dose not serve as a biomarker. Arctigenin, inhibition of mitochondrial complex I, plasma lactate concentration, phase I clinical trial of GBS-01, Cori cycle.

  6. BIOCHEMICAL EFFECTS IN NORMAL AND STONE FORMING RATS TREATED WITH THE RIPE KERNEL JUICE OF PLANTAIN (MUSA PARADISIACA)

    PubMed Central

    Devi, V. Kalpana; Baskar, R.; Varalakshmi, P.

    1993-01-01

    The effect of Musa paradisiaca stem kernel juice was investigated in experimental urolithiatic rats. Stone forming rats exhibited a significant elevation in the activities of two oxalate synthesizing enzymes - Glycollic acid oxidase and Lactate dehydrogenase. Deposition and excretion of stone forming constituents in kidney and urine were also increased in these rats. The enzyme activities and the level of crystalline components were lowered with the extract treatment. The extract also reduced the activities of urinary alkaline phosphatase, lactate dehydrogenase, r-glutamyl transferase, inorganic pyrophosphatase and β-glucuronidase in calculogenic rats. No appreciable changes were noticed with leucine amino peptidase activity in treated rats. PMID:22556626

  7. Pretreatment Serum Lactate Dehydrogenase and N Classification Predict Long-Term Survival and Distant Metastasis in Patients With Nasopharyngeal Carcinoma Who Have A Positive Family History of Cancer

    PubMed Central

    Zhang, Wenna; Chen, Yupei; Zhou, Guanqun; Liu, Xu; Chen, Lei; Tang, Linglong; Mao, Yanping; Sun, Ying; Ma, Jun

    2015-01-01

    Abstract The purpose of the present study was to evaluate prognostic factors in patients with nasopharyngeal carcinoma (NPC) from the endemic area of southern China who have a positive family history (FH) of cancer. Retrospective analysis of 600 patients with nondisseminated NPC and a positive FH was conducted. The prognostic value of different factors for overall survival (OS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and local relapse-free survival (LRFS) were assessed using Cox regression models. The 3-year OS, DMFS, DFS, and LRFS rates were 93.8%, 91.3%, 86.3%, and 93.8%, respectively. The FH tumor type was NPC for 226/600 (37.7%) patients and other cancers for 374/600 (62.3%) patients. The 3-year OS and DMFS rates for patients with an FH of NPC were 91.2% and 89.8%, respectively. Thirty of 600 (5.0%) patients had elevated pretreatment serum lactate dehydrogenase (LDH >245.0 IU/L). In multivariate analysis, N classification (HR 4.56, 95% CI 2.13–9.74, P < 0.0001) and elevated pretreatment serum LDH (HR 2.87, 95% CI 1.08–7.62, P = 0.034) were independent prognosticators for OS. Female patients (HR 0.42, 95% CI 0.19–0.95, P = 0.037) and patients with normal pretreatment serum LDH (HR 2.42, 95% CI 1.02–5.78, P = 0.046) had better DMFS. Elevated pretreatment serum LDH and N classification are independent prognostic factors for poorer survival in patients with NPC who have a positive FH of cancer. PMID:26376394

  8. Reaction norm of fertility traits adjusted for protein and fat production level across lactations in Holstein cattle.

    PubMed

    Menendez-Buxadera, A; Carabaño, M J; Gonzalez-Recio, O; Cue, R I; Ugarte, E; Alenda, R

    2013-07-01

    A total of 304,001 artificial insemination outcomes in up to 7 lactations from 142,389 Holstein cows, daughters of 5,349 sires and 101,433 dams, calving between January 1995 and December 2007 in 1,347 herds were studied by a reaction norm model. The (co)variance components for days to first service (DFS), days open, nonreturn rate in the first service (NRFS), and number of services per conception were estimated by 6 models: 3 Legendre polynomial degrees for the genetic effects and adjustment or not for the level of fat plus protein (FP) production recorded at day closest to DFS. For all traits and type of FP adjustment, a second degree polynomial showed the best fit. The use of the adjusted FP model did not increase the level of genetic (co)variance components except for DFS. The heritability for each of the traits was low in general (0.03-0.10) and increased from the first to fourth calving; nevertheless, very important variability was found for the estimated breeding value (EBV) of the sires. The genetic correlations (rg) were close to unity between adjacent calvings, but decreased for most distant parities, ranging from rg=0.36 (for DFS) to rg=0.63 (for NRFS), confirming the existence of heterogeneous genetic (co)variance components and EBV across lactations. The results of the eigen decomposition of rg shows that the first eigenvalue explained between 82 to 92% and the second between 8 to 14% of the genetic variance for all traits; therefore, a deformation of the overall mean trajectory for reproductive performance across the trajectory of the different calving could be expected if selection favored these eigenfunctions. The results of EBV for the 50 best sires showed a substantial reranking and variation in the shape of response across lactations. The more important aspect to highlight, however, is the difference between the EBV of the same sires in different calvings, a characteristic known as plasticity, which is particularly important for DFS and NRFS. This

  9. Blood ammonia and lactate as markers of muscle metabolites during leg press exercise.

    PubMed

    Gorostiaga, Esteban M; Navarro-Amézqueta, Ion; Calbet, Jose A L; Sánchez-Medina, Luis; Cusso, Roser; Guerrero, Mario; Granados, Cristina; González-Izal, Miriam; Ibáñez, Javier; Izquierdo, Mikel

    2014-10-01

    To examine whether blood lactate and ammonia concentrations can be used to estimate the functional state of the muscle contractile machinery with regard to muscle lactate and adenosine triphosphate (ATP) levels during leg press exercise. Thirteen men (age, 34 ± 5 years; 1 repetition maximum leg press strength 199 ± 33 kg) performed either 5 sets of 10 repetitions to failure (5×10RF), or 10 sets of 5 repetitions not to failure (10×5RNF) with the same initial load (10RM) and interset rests (2 minutes) on 2 separate sessions in random order. Capillary blood samples were obtained before and during exercise and recovery. Six subjects underwent vastus lateralis muscle biopsies at rest, before the first set and after the final exercise set. The 5×10RF resulted in a significant and marked decrease in power output (37%), muscle ATP content (24%), and high levels of muscle lactate (25.0 ± 8.1 mmol·kg wet weight), blood lactate (10.3 ± 2.6 mmol·L), and blood ammonia (91.6 ± 40.5 μmol·L). During 10×5RNF no or minimal changes were observed. Significant correlations were found between: (a) blood ammonia and muscle ATP (r = -0.75), (b) changes in peak power output and blood ammonia (r = -0.87) and blood lactate (r = -0.84), and (c) blood and muscle lactate (r = 0.90). Blood lactate and ammonia concentrations can be used as extracellular markers for muscle lactate and ATP contents, respectively. The decline in mechanical power output can be used to indirectly estimate blood ammonia and lactate during leg press exercise.

  10. Redox Specificity of 2-Hydroxyacid-Coupled NAD+/NADH Dehydrogenases: A Study Exploiting “Reactive” Arginine as a Reporter of Protein Electrostatics

    PubMed Central

    Durani, Susheel

    2013-01-01

    With “reactive” arginine as a kinetic reporter, 2-hydroxyacid dehydrogenases are assessed in basis of their specialization as NAD+-reducing or NADH-oxidizing enzymes. Specifically, M4 and H4 lactate dehydrogenases (LDHs) and cytoplasmic and mitochondrial malate dehydrogenases (MDHs) are compared to assess if their coenzyme specificity may involve electrostatics of cationic or neutral nicotinamide structure as the basis. The enzymes from diverse eukaryote and prokaryote sources thus are assessed in “reactivity” of functionally-critical arginine as a function of salt concentration and pH. Electrostatic calculations were performed on “reactive” arginines and found good correspondence with experiment. The reductive and oxidative LDHs and MDHs are assessed in their count over ionizable residues and in placement details of the residues in their structures as proteins. The variants found to be high or low in ΔpKa of “reactive” arginine are found to be also strong or weak cations that preferentially oxidize NADH (neutral nicotinamide structure) or reduce NAD+ (cationic nicotinamide structure). The ionized groups of protein structure may thus be important to redox specificity of the enzyme on basis of electrostatic preference for the oxidized (cationic nicotinamide) or reduced (neutral nicotinamide) coenzyme. Detailed comparisons of isozymes establish that the residues contributing in their redox specificity are scrambled in structure of the reductive enzyme. PMID:24391777

  11. Diminution in energy expenditure during lactation.

    PubMed Central

    Illingworth, P J; Jung, R T; Howie, P W; Leslie, P; Isles, T E

    1986-01-01

    Energy expenditure at rest and in response to a meal and to an infusion of noradrenaline was measured in 12 lactating women and compared with that in seven bottle feeding women and seven non-pregnant, non-lactating controls. The energy response of the lactating women was remeasured after lactation stopped. During lactation the resting metabolic rate was unaltered but there was a reduced response to infusion of noradrenaline and to a meal, which increased to normal control values after lactation stopped. Such reductions in expenditure were not found in women who had been bottle feeding and were tested at a similar six to eight weeks post partum. These findings suggest that metabolic efficiency is enhanced in lactating women, who may not need to increase energy intake to the extent suggested by current recommended dietary allowances. PMID:3081114

  12. Zoledronate prevents lactation induced bone loss and results in additional post-lactation bone mass in mice.

    PubMed

    Wendelboe, Mette Høegh; Thomsen, Jesper Skovhus; Henriksen, Kim; Vegger, Jens Bay; Brüel, Annemarie

    2016-06-01

    In rodents, lactation is associated with a considerable and very rapid bone loss, which almost completely recovers after weaning. The aim of the present study was to investigate whether the bisphosphonate Zoledronate (Zln) can inhibit lactation induced bone loss, and if Zln interferes with recovery of bone mass after lactation has ceased. Seventy-six 10-weeks-old NMRI mice were divided into the following groups: Baseline, Pregnant, Lactation, Lactation+Zln, Recovery, Recovery+Zln, and Virgin Control (age-matched). The lactation period was 12days, then the pups were removed, and thereafter recovery took place for 28days. Zln, 100μg/kg, was given s.c. on the day of delivery, and again 4 and 8days later. Mechanical testing, μCT, and dynamic histomorphometry were performed. At L4, lactation resulted in a substantial loss of bone strength (-55% vs. Pregnant, p<0.01), BV/TV (-40% vs. Pregnant, p<0.01), and trabecular thickness (Tb.Th) (-29% vs. Pregnant, p<0.001). Treatment with Zln completely prevented lactation induced loss of bone strength, BV/TV, and Tb.Th at L4. Full recovery of micro-architectural and mechanical properties was found 28days after weaning in vehicle-treated mice. Interestingly, the recovery group treated with Zln during the lactation period had higher BV/TV (+45%, p<0.01) and Tb.Th (+16%, p<0.05) compared with virgin controls. Similar results were found at the proximal tibia and femur. This indicates that Zln did not interfere with the bone formation taking place after weaning. On this background, we conclude that post-lactation bone formation is not dependent on a preceding lactation induced bone loss. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Intracellular NADPH Levels Affect the Oligomeric State of the Glucose 6-Phosphate Dehydrogenase

    PubMed Central

    Tramonti, Angela; Lanini, Claudio; Cialfi, Samantha; De Biase, Daniela; Falcone, Claudio

    2012-01-01

    In the yeast Kluyveromyces lactis, glucose 6-phosphate dehydrogenase (G6PDH) is detected as two differently migrating forms on native polyacrylamide gels. The pivotal metabolic role of G6PDH in K. lactis led us to investigate the mechanism controlling the two activities in respiratory and fermentative mutant strains. An extensive analysis of these mutants showed that the NAD+(H)/NADP+(H)-dependent cytosolic alcohol (ADH) and aldehyde (ALD) dehydrogenase balance affects the expression of the G6PDH activity pattern. Under fermentative/ethanol growth conditions, the concomitant activation of ADH and ALD activities led to cytosolic accumulation of NADPH, triggering an alteration in the oligomeric state of the G6PDH caused by displacement/release of the structural NADP+ bound to each subunit of the enzyme. The new oligomeric G6PDH form with faster-migrating properties increases as a consequence of intracellular redox unbalance/NADPH accumulation, which inhibits G6PDH activity in vivo. The appearance of a new G6PDH-specific activity band, following incubation of Saccharomyces cerevisiae and human cellular extracts with NADP+, also suggests that a regulatory mechanism of this activity through NADPH accumulation is highly conserved among eukaryotes. PMID:23064253

  14. Demonstration of 3 alpha(17 beta)-hydroxysteroid dehydrogenase distinct from 3 alpha-hydroxysteroid dehydrogenase in hamster liver.

    PubMed Central

    Ohmura, M; Hara, A; Nakagawa, M; Sawada, H

    1990-01-01

    NAD(+)-linked and NADP(+)-linked 3 alpha-hydroxysteroid dehydrogenases were purified to homogeneity from hamster liver cytosol. The two monomeric enzymes, although having similar molecular masses of 38,000, differed from each other in pI values, activation energy and heat stability. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with protease. The NADP(+)-linked enzyme catalysed the oxidoreduction of various 3 alpha-hydroxysteroids, whereas the NAD(+)-linked enzyme oxidized the 3 alpha-hydroxy group of pregnanes and some bile acids, and the 17 beta-hydroxy group of testosterone and androstanes. The thermal stabilities of the 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the NAD(+)-linked enzyme were identical, and the two enzyme activities were inhibited by mixing 17 beta- and 3 alpha-hydroxysteroid substrates, respectively. Medroxyprogesterone acetate, hexoestrol and 3 beta-hydroxysteroids competitively inhibited 3 alpha- and 17 beta-hydroxysteroid dehydrogenase activities of the enzyme. These results show that hamster liver contains a 3 alpha(17 beta)-hydroxysteroid dehydrogenase structurally and functionally distinct from 3 alpha-hydroxysteroid dehydrogenase. Images Fig. 1. Fig. 2. PMID:2317205

  15. A Portable Luminometer with a Disposable Electrochemiluminescent Biosensor for Lactate Determination

    PubMed Central

    Martínez-Olmos, Antonio; Ballesta-Claver, Julio; Palma, Alberto J.; Valencia-Mirón, Maria del Carmen; Capitán-Vallvey, Luis Fermin

    2009-01-01

    A hand-held luminometer for measuring electrochemiluminescence (ECL) for lactate determination and based on one-shot biosensors fabricated using screen-printed electrodes is described. The lactate recognition system is based on lactate oxidase and the transduction system consists of electro-oxidation of luminol, with all the reagents immobilized in a Methocel membrane. The membrane composition and reaction conditions have been optimized to obtain adequate sensitivity. The luminometer is based on a large silicon photodiode as detector and includes a programmable potentiostat to initialize the chemical reaction and signal processing circuitry, designed to acquire a low level photocurrent with offset cancelation, low pass filtering for noise attenuation and adjustable gain up to 1012 V/A. The one-shot biosensor responds to lactate rapidly, with an acquisition time of 2.5 min, obtaining a linear dependence from 8 × 10−6 to 2 × 10−4 M, a detection limit of 2.4 × 10−6 M and a sensor-to-sensor reproducibility (relative standard deviation, RSD) of around 7–10 % at the medium level of the range. PMID:22408475

  16. An In Vitro Model of the Horse Gut Microbiome Enables Identification of Lactate-Utilizing Bacteria That Differentially Respond to Starch Induction

    PubMed Central

    Biddle, Amy S.; Black, Samuel J.; Blanchard, Jeffrey L.

    2013-01-01

    Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical diets provided bacterial communities for this in vitro study. Triplicate microcosms of fecal slurries were enriched with lactate and/or starch. Metabolic products (short chain fatty acids, headspace gases, and hydrogen sulfide) were measured and microbial community compositions determined using Illumina 16S rRNA sequencing over 12-hour intervals. We report that patterns of change in short chain fatty acid levels and pH in our in vitro system are similar to those seen in in vivo laminitis induction models. Community differences between microcosms with disparate abilities to clear excess lactate suggest profiles conferring resistance of starch-induction conditions. Where lactate levels recover following starch induction conditions, propionate and acetate levels rise correspondingly and taxa related to Megasphaera elsdenii reach levels exceeding 70% relative abundance. In lactate and control cultures, taxa related to Veillonella montpellierensis are enriched as lactate levels fall. Understanding these community differences and factors promoting the growth of specific lactate utilizing taxa may be useful to prevent acidosis under starch-induction conditions. PMID:24098591

  17. An in vitro model of the horse gut microbiome enables identification of lactate-utilizing bacteria that differentially respond to starch induction.

    PubMed

    Biddle, Amy S; Black, Samuel J; Blanchard, Jeffrey L

    2013-01-01

    Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical diets provided bacterial communities for this in vitro study. Triplicate microcosms of fecal slurries were enriched with lactate and/or starch. Metabolic products (short chain fatty acids, headspace gases, and hydrogen sulfide) were measured and microbial community compositions determined using Illumina 16S rRNA sequencing over 12-hour intervals. We report that patterns of change in short chain fatty acid levels and pH in our in vitro system are similar to those seen in in vivo laminitis induction models. Community differences between microcosms with disparate abilities to clear excess lactate suggest profiles conferring resistance of starch-induction conditions. Where lactate levels recover following starch induction conditions, propionate and acetate levels rise correspondingly and taxa related to Megasphaeraelsdenii reach levels exceeding 70% relative abundance. In lactate and control cultures, taxa related to Veillonellamontpellierensis are enriched as lactate levels fall. Understanding these community differences and factors promoting the growth of specific lactate utilizing taxa may be useful to prevent acidosis under starch-induction conditions.

  18. Base compositions of genes encoding alpha-actin and lactate dehydrogenase-A from differently adapted vertebrates show no temperature-adaptive variation in G + C content.

    PubMed

    Ream, Rachael A; Johns, Glenn C; Somero, George N

    2003-01-01

    There is a long-standing debate in molecular evolution concerning the putative importance of GC content in adapting the thermal stabilities of DNA and RNA. Most studies of this relationship have examined broad-scale compositional patterns, for example, total GC percentages in genomes and occurrence of GC-rich isochores. Few studies have systematically examined the GC contents of individual orthologous genes from differently thermally adapted species. When this has been done, the emphasis has been on comparing large numbers of genes in only a few species. We have approached the GC-adaptation temperature hypothesis in a different manner by examining patterns of base composition of genes encoding lactate dehydrogenase-A (ldh-a) and alpha-actin (alpha-actin) from 51 species of vertebrates whose adaptation temperatures ranged from -1.86 degrees C (Antarctic fishes) to approximately 45 degrees C (desert reptile). No significant positive correlation was found between any index of GC content (GC content of the entire sequence, GC content of the third codon position [GC(3)], and GC content at fourfold degenerate sites [GC(4)]) and any index of adaptation temperature (maximal, mean, or minimal body temperature). For alpha-actin, slopes of regression lines for all comparisons did not differ significantly from zero. For ldh-a, negative correlations between adaptation temperature and total GC content, GC(3), and GC(4) were observed but were shown to be due entirely to phylogenetic influences (as revealed by independent contrast analyses). This comparison of GC content across a wide range of ectothermic ("cold-blooded") and endothermic ("warm-blooded") vertebrates revealed that frogs of the genus Xenopus, which have commonly been used as a representative cold-blooded species, in fact are outliers among ectotherms for the alpha-actin analyses, raising concern about the appropriateness of choosing these amphibians as representative of ectothermic vertebrates in general. Our study

  19. Yeast surface display of dehydrogenases in microbial fuel-cells.

    PubMed

    Gal, Idan; Schlesinger, Orr; Amir, Liron; Alfonta, Lital

    2016-12-01

    Two dehydrogenases, cellobiose dehydrogenase from Corynascus thermophilus and pyranose dehydrogenase from Agaricus meleagris, were displayed for the first time on the surface of Saccharomyces cerevisiae using the yeast surface display system. Surface displayed dehydrogenases were used in a microbial fuel cell and generated high power outputs. Surface displayed cellobiose dehydrogenase has demonstrated a midpoint potential of -28mV (vs. Ag/AgCl) at pH=6.5 and was used in a mediator-less anode compartment of a microbial fuel cell producing a power output of 3.3μWcm(-2) using lactose as fuel. Surface-displayed pyranose dehydrogenase was used in a microbial fuel cell and generated high power outputs using different substrates, the highest power output that was achieved was 3.9μWcm(-2) using d-xylose. These results demonstrate that surface displayed cellobiose dehydrogenase and pyranose dehydrogenase may successfully be used in microbial bioelectrochemical systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Prevention of acute/severe hypoglycemia-induced neuron death by lactate administration.

    PubMed

    Won, Seok Joon; Jang, Bong Geom; Yoo, Byung Hoon; Sohn, Min; Lee, Min Woo; Choi, Bo Young; Kim, Jin Hee; Song, Hong Ki; Suh, Sang Won

    2012-06-01

    Hypoglycemia-induced cerebral neuropathy can occur in patients with diabetes who attempt tight control of blood glucose and may lead to cognitive dysfunction. Accumulating evidence from animal models suggests that hypoglycemia-induced neuronal death is not a simple result of glucose deprivation, but is instead the end result of a multifactorial process. In particular, the excessive activation of poly (ADP-ribose) polymerase-1 (PARP-1) consumes cytosolic nicotinamide adenine dinucleotide (NAD(+)), resulting in energy failure. In this study, we investigate whether lactate administration in the absence of cytosolic NAD(+) affords neuroprotection against hypoglycemia-induced neuronal death. Intraperitoneal injection of sodium L-lactate corrected arterial blood pH and blood lactate concentration after hypoglycemia. Lactate administered without glucose was not sufficient to promote electroencephalogram recovery from an isoelectric state during hypoglycemia. However, supplementation of glucose with lactate reduced neuronal death by ∼80% in the hippocampus. Hypoglycemia-induced superoxide production and microglia activation was also substantially reduced by administration of lactate. Taken together, these results suggest an intriguing possibility: that increasing brain lactate following hypoglycemia offsets the decrease in NAD(+) due to overactivation of PARP-1 by acting as an alternative energy substrate that can effectively bypass glycolysis and be fed directly to the citric acid cycle to maintain cellular ATP levels.

  1. Combination of Acute Physiology and Chronic Health Evaluation II score, early lactate area, and N-terminal prohormone of brain natriuretic peptide levels as a predictor of mortality in geriatric patients with septic shock.

    PubMed

    Wang, Hao; Li, Zhong; Yin, Mei; Chen, Xiao-Mei; Ding, Shi-Fang; Li, Chen; Zhai, Qian; Li, Yuan; Liu, Han; Wu, Da-Wei

    2015-04-01

    Given the high mortality rates in elderly patients with septic shock, the early recognition of patients at greatest risk of death is crucial for the implementation of early intervention strategies. Serum lactate and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels are often elevated in elderly patients with septic shock and are therefore important biomarkers of metabolic and cardiac dysfunction. We hypothesized that a risk stratification system that incorporates the Acute Physiology and Chronic Health Evaluation (APACHE) II score and lactate and NT-proBNP biomarkers would better predict mortality in geriatric patients with septic shock than the APACHE II score alone. A single-center prospective study was conducted from January 2012 to December 2013 in a 30-bed intensive care unit of a triservice hospital. The lactate area score was defined as the sum of the area under the curve of serial lactate levels measured during the 24 hours following admission divided by 24. The NT-proBNP score was assigned based on NT-proBNP levels measured at admission. The combined score was calculated by adding the lactate area and NT-proBNP scores to the APACHE II score. Multivariate logistic regression analyses and receiver operating characteristic curves were used to evaluate which variables and scoring systems served as the best predictors of mortality in elderly septic patients. A total of 115 patients with septic shock were included in the study. The overall 28-day mortality rate was 67.0%. When compared to survivors, nonsurvivors had significantly higher lactate area scores, NT-proBNP scores, APACHE II scores, and combined scores. In the multivariate regression model, the combined score, lactate area score, and mechanical ventilation were independent risk factors associated with death. Receiver operating characteristic curves indicated that the combined score had significantly greater predictive power when compared to the APACHE II score or the NT-proBNP score

  2. Heritability of methane emissions from dairy cows over a lactation measured on commercial farms.

    PubMed

    Pszczola, M; Rzewuska, K; Mucha, S; Strabel, T

    2017-11-01

    Methane emission is currently an important trait in studies on ruminants due to its environmental and economic impact. Recent studies were based on short-time measurements on individual cows. As methane emission is a longitudinal trait, it is important to investigate its changes over a full lactation. In this study, we aimed to estimate the heritability of the estimated methane emissions from dairy cows using Fourier-transform infrared spectroscopy during milking in an automated milking system by implementing the random regression method. The methane measurements were taken on 485 Polish Holstein-Friesian cows at 2 commercial farms located in western Poland. The overall daily estimated methane emission was 279 g/d. Genetic variance fluctuated over the course of lactation around the average level of 1,509 (g/d), with the highest level, 1,866 (g/d), at the end of the lactation. The permanent environment variance values started at 2,865 (g/d) and then dropped to around 846 (g/d) at 100 d in milk (DIM) to reach the level of 2,444 (g/d) at the end of lactation. The residual variance was estimated at 2,620 (g/d). The average repeatability was 0.25. The heritability level fluctuated over the course of lactation, starting at 0.23 (SE 0.12) and then increasing to its maximum value of 0.3 (SE 0.08) at 212 DIM and ending at the level of 0.27 (SE 0.12). Average heritability was 0.27 (average SE 0.09). We have shown that estimated methane emission is a heritable trait and that the heritability level changes over the course of lactation. The observed changes and low genetic correlations between distant DIM suggest that it may be important to consider the period in which methane phenotypes are collected.

  3. Relationship among blood indicators of lipomobilization and hepatic function during early lactation in high-yielding dairy cows

    PubMed Central

    Muiño, Rodrigo; Pereira, Víctor; Campos, Rómulo; Benedito, José Luis

    2011-01-01

    Blood indicators are used as a tool to diagnose metabolic disorders. The present work was conducted to study the relationships among blood indicators of lipomobilization and hepatic function in high-yielding dairy cows. Two groups of Holstein cows were studied: 27 early lactation cows and 14 mid lactation cows from four different herds with similar husbandry characteristics in Galicia, Spain. Blood samples were obtained to measure beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), triglycerides (TG), and the activity of aspartate transaminase (AST) and gamma-glutamyl transferase. Cows in early lactation had higher levels of BHB and NEFA than mid lactation cows. High lipomobilization (NEFA > 400 µmol/L) was detected in 67% and 7% of early lactation and mid lactation cows, respectively, while subclinical ketosis (BHB > 1.2 mmol/L) was detected in 41% and 28% of the early lactation and lactation cows, respectively. TG concentrations were low in all cows suffering subclinical ketosis and in 61% of the cows with high lipomobilization. During early lactation, 30% of cows suffered hepatic lipidosis as detected by levels of AST. Compromised hepatic function was observed in early lactation cows as shown by lower concentrations of glucose, total protein, and urea. PMID:21897097

  4. Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity

    PubMed Central

    Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S.; Soya, Hideaki

    2017-01-01

    Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry–based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain. PMID:28515312

  5. Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity.

    PubMed

    Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S; Soya, Hideaki

    2017-06-13

    Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.

  6. Suppression of male reproduction in rats after exposure to sodium fluoride during early stages of development

    NASA Astrophysics Data System (ADS)

    Reddy, P. Sreedhar; Pushpalatha, T.; Reddy, P. Sreenivasula

    2007-07-01

    Sodium fluoride (NaF), a widespread natural pollutant was given to sperm-positive female rats throughout gestation and lactation at a dose of 4.5 and 9.0 ppm via drinking water. The neonates were allowed to grow up to 90 days on tap water, and then sperm parameters, testicular steroidogenic marker enzyme activity levels, and circulatory hormone levels were studied. The sperm count, sperm motility, sperm coiling (hypoosmotic swelling test), and sperm viability were decreased in experimental rats when compared with controls. The activity levels of testicular steroidogenic marker enzymes (3β hydroxysteroid dehydrogenase and 17β hydroxysteroid dehydrogenase) were significantly decreased in experimental animals indicating decreased steroidogenesis. The serum testosterone, follicle stimulating hormone and luteinizing hormone levels were also significantly altered in experimental animals. Our data indicate that exposure to NaF during gestation and lactation affects male reproduction in adult rats by decreasing spermatogenesis and steroidogenesis.

  7. Effects of acute L-carnitine intake on metabolic and blood lactate levels of elite badminton players.

    PubMed

    Eroğlu, Hüseyin; Senel, Omer; Güzel, Nevin A

    2008-04-01

    Purpose of this study is to research the effects of acute L-Carnitine intake on badminton players' metabolic and blood lactate values. A total of 16 Turkish national badminton players (8 male, 8 female) were voluntarily participated into study. MaxVO2, MET, energy consumption, HR (heart rate), VE (minute ventilation), R (respiratory exchange ratio), AT (anaerobic threshold), oxygen pulse and blood lactate (LA) of subjects were measured by Sensormedics VmaxST and Accutrend Lactate Analyzer. The participants were subjected to the test protocol twice before and after 2g of L-Carnitine intake. The data were evaluated by the use of SPSS 13.0 for Windows. No significant differences were found between 1st. (without L-Carnitine intake) and 2nd. (with L-Carnitine intake) measurements of female participants as regards to all measured parameters. There was a significant difference in EMHR (exercise maximum heart rate) of males between two measurements (p<0.05). However the differences in other parameters were not significant. AT values of female subjects were not significant difference (p>0.05). Respiratory exchange ratio of males was significantly different at anaerobic threshold (p<0.05). Results of this study show that L-carnitine intake one hour prior to the exercise has no effect on the metabolic and blood lactate values of badminton players.

  8. 21 CFR 184.1311 - Ferrous lactate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... prepared by reacting calcium lactate or sodium lactate with ferrous sulfate, direct reaction of lactic acid with iron filings, reaction of ferrous chloride with sodium lactate, or reaction of ferrous sulfate...

  9. 21 CFR 184.1311 - Ferrous lactate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... It is prepared by reacting calcium lactate or sodium lactate with ferrous sulfate, direct reaction of lactic acid with iron filings, reaction of ferrous chloride with sodium lactate, or reaction of ferrous...

  10. [The nutrition status of lactating women in China].

    PubMed

    Dong, C X; Yin, S A

    2016-12-06

    Nutritional status of lactating women is considered to be a quantitative indicator reflecting the status of reproductive health. To improve nutrition status of lactating women and promote breastfeeding through targeted intervention measures, their dietary and nutritional situations, and related problems, should be fully understood. Generally, energy and macronutrient intake of lactating women can reach or exceed recommended levels, especially during the first month postpartum. However, the intake of some micronutrients is difficult to meet the requirement. These include vitamin D and vitamin B 12 , iron and zinc, and calcium, if milk and dairy product consumption is very low, suggesting that extra supplementation should be considered. The percentage of obesity or postpartum weight retention showed an increasing trend in urban and rural areas and was related to decreased or delayed breastfeeding or early weaning. Common micronutrient deficiencies included in vitamin D, vitamin B 12 , iron and zinc. In this paper, we reviewed various characteristics of the lactating women, including nutritional status, postpartum weight retention and micronutrient deficiencies. We suggest that improved suggestions be developed for China, based on data from National Nutrition Survey, Chinese National Nutrition and Health Surveillance and related studies conducted over the past 10 years.

  11. Lactating Mother and Psychotropic Drugs

    PubMed Central

    Tripathi, B. M.; Majumder, Pradipta

    2010-01-01

    Usage of psychotropics during pregnancy and lactation has always been a topic of debate and controversy. The debate stems from the potential adverse effects on the growing fetus or infants due to the transfer of psychotropic drugs through placenta or breast milk of mothers receiving them; and the problem of discontinuing psychotropics in lactating mother considering chances of relapse. However, most of the psychotropics are found to be relatively safe when used cautiously during the lactation phase. This article describes available data on the use of psychotropics in lactating mothers, in particular, in relation to the safety profile of infants. PMID:21327172

  12. 21 CFR 862.1420 - Isocitric dehydrogenase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Systems § 862.1420 Isocitric dehydrogenase test system. (a) Identification. An isocitric dehydrogenase test system is a device intended to measure the activity of the enzyme isocitric dehydrogenase in serum... disease such as viral hepatitis, cirrhosis, or acute inflammation of the biliary tract; pulmonary disease...

  13. Elevated CSF-lactate is a reliable marker of mitochondrial disorders in children even after brief seizures.

    PubMed

    Magner, Martin; Szentiványi, Karol; Svandová, Ivana; Ješina, Pavel; Tesařová, Markéta; Honzík, Tomáš; Zeman, Jiří

    2011-03-01

    Increased lactate is an important biochemical marker in diagnosis of children with suspicion of mitochondrial disorders. A diagnostic dilemma may originate if analyses are performed after seizures, when the increased lactate levels may be considered to result from the seizures. To address this problem, we ascertained the diagnostic value of lactate and alanine in blood (B) and cerebrospinal fluid (CSF) in children with mitochondrial disorders (n = 24), epilepsy (n = 32), psychomotor retardation (n = 23), meningitis (n = 12) and meningism (n = 16). Lactate concentration was measured using a spectrophotometric method. Amino acids in serum and CSF were analyzed by ion exchange chromatography with ninhydrin detection. Average blood and CSF-lactate levels were significantly higher in children with mitochondrial disorders (3.87 ± 0.48 and 4.43 ± 0.55 mmol/l) and meningitis (2.77 ± 0.45 and 8.58 ± 1.08 mmol/l) than in children with epilepsy (1.72 ± 0.13 and 1.62 ± 0.04 mmol/l), psychomotor retardation (1.79 ± 1.40 and 1.68 ± 0.06 mmol/l) or meningism (1.70 ± 0.13 and 1.64 ± 0.07 mmol/l). Blood and CSF-alanine levels were also higher in children with mitochondrial disorders (558 ± 44 and 51 ± 8 μmol/l) than in children with epilepsy (327 ± 23 and 27 ± 3 μmol/l) or psychomotor retardation (323 ± 27 and 26 ± 3 μmol/l). The CSF-lactate levels of children with epilepsy were similar whether the samples were obtained 3 ± 0.6 h after an attack of brief seizures or from children without history of recent seizures. Elevated cerebrospinal fluid lactate level is a reliable marker pointing to mitochondrial origin of disease, even in children who have recently suffered short-lasting seizures. Some children with mitochondrial disorders manifest only mild or intermittent elevation of lactate levels. Copyright © 2010 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  14. Functional interaction between bicarbonate transporters and carbonic anhydrase modulates lactate uptake into mouse cardiomyocytes.

    PubMed

    Peetz, Jan; Barros, L Felipe; San Martín, Alejandro; Becker, Holger M

    2015-07-01

    Blood-derived lactate is a precious energy substrate for the heart muscle. Lactate is transported into cardiomyocytes via monocarboxylate transporters (MCTs) together with H(+), which couples lactate uptake to cellular pH regulation. In this study, we have investigated how the interplay between different acid/base transporters and carbonic anhydrases (CA), which catalyze the reversible hydration of CO2, modulates the uptake of lactate into isolated mouse cardiomyocytes. Lactate transport was estimated both as lactate-induced acidification and as changes in intracellular lactate levels measured with a newly developed Förster resonance energy transfer (FRET) nanosensor. Recordings of intracellular pH showed an increase in the rate of lactate-induced acidification when CA was inhibited by 6-ethoxy-2-benzothiazolesulfonamide (EZA), while direct measurements of lactate flux demonstrated a decrease in MCT transport activity, when CA was inhibited. The data indicate that catalytic activity of extracellular CA increases lactate uptake and counteracts intracellular lactate-induced acidification. We propose a hypothetical model, in which HCO3 (-), formed from cell-derived CO2 at the outer surface of the cardiomyocyte plasma membrane by membrane-anchored, extracellular CA, is transported into the cell via Na(+)/HCO3 (-) cotransport to counteract intracellular acidification, while the remaining H(+) stabilizes extracellular pH at the surface of the plasma membrane during MCT activity to enhance lactate influx into cardiomyocytes.

  15. Diaphorase Coupling Protocols for Red-Shifting Dehydrogenase Assays

    PubMed Central

    Davis, Mindy I.; Shen, Min; Simeonov, Anton

    2016-01-01

    Abstract Dehydrogenases are an important target for the development of cancer therapeutics. Dehydrogenases either produce or consume NAD(P)H, which is fluorescent but at a wavelength where many compounds found in chemical libraries are also fluorescent. By coupling dehydrogenases to diaphorase, which utilizes NAD(P)H to produce the fluorescent molecule resorufin from resazurin, the assay can be red-shifted into a spectral region that reduces interference from compound libraries. Dehydrogenases that produce NAD(P)H, such as isocitrate dehydrogenase 1 (IDH1), can be read in kinetic mode. Dehydrogenases that consume NAD(P)H, such as mutant IDH1 R132H, can be read in endpoint mode. Here, we report protocols for robust and miniaturized 1,536-well assays for WT IDH1 and IDH1 R132H coupled to diaphorase, and the counterassays used to further detect compound interference with the coupling reagents. This coupling technique is applicable to dehydrogenases that either produce or consume NAD(P)H, and the examples provided here can act as guidelines for the development of high-throughput screens against this enzyme class. PMID:27078681

  16. Role of Microsomal Retinol/Sterol Dehydrogenase-Like Short-Chain Dehydrogenases/Reductases in the Oxidation and Epimerization of 3α-Hydroxysteroids in Human Tissues

    PubMed Central

    Belyaeva, Olga V.; Chetyrkin, Sergei V.; Clark, Amy L.; Kostereva, Natalia V.; SantaCruz, Karen S.; Chronwall, Bibie M.; Kedishvili, Natalia Y.

    2008-01-01

    Allopregnanolone (ALLO) and androsterone (ADT) are naturally occurring 3α-hydroxysteroids that act as positive allosteric regulators of γ-aminobutyric acid type A receptors. In addition, ADT activates nuclear farnesoid X receptor and ALLO activates pregnane X receptor. At least with respect to γ-aminobutyric acid type A receptors, the biological activity of ALLO and ADT depends on the 3α-hydroxyl group and is lost upon its conversion to either 3-ketosteroid or 3β-hydroxyl epimer. Such strict structure-activity relationships suggest that the oxidation or epimerization of 3α-hydroxysteroids may serve as physiologically relevant mechanisms for the control of the local concentrations of bioactive 3α-hydroxysteroids. The exact enzymes responsible for the oxidation and epimerization of 3α-hydroxysteroids in vivo have not yet been identified, but our previous studies showed that microsomal nicotinamide adenine dinucleotide-dependent short-chain dehydrogenases/reductases (SDRs) with dual retinol/sterol dehydrogenase substrate specificity (RoDH-like group of SDRs) can oxidize and epimerize 3α-hydroxysteroids in vitro. Here, we present the first evidence that microsomal nicotinamide adenine dinucleotide-dependent 3α-hydroxysteroid dehydrogenase/epimerase activities are widely distributed in human tissues with the highest activity levels found in liver and testis and lower levels in lung, spleen, brain, kidney, and ovary. We demonstrate that RoDH-like SDRs contribute to the oxidation and epimerization of ALLO and ADT in living cells, and show that RoDH enzymes are expressed in tissues that have microsomal 3α-hydroxysteroid dehydrogenase/epimerase activities. Together, these results provide further support for the role of RoDH-like SDRs in human metabolism of 3α-hydroxysteroids and offer a new insight into the enzymology of ALLO and ADT inactivation. PMID:17289849

  17. Role of microsomal retinol/sterol dehydrogenase-like short-chain dehydrogenases/reductases in the oxidation and epimerization of 3alpha-hydroxysteroids in human tissues.

    PubMed

    Belyaeva, Olga V; Chetyrkin, Sergei V; Clark, Amy L; Kostereva, Natalia V; SantaCruz, Karen S; Chronwall, Bibie M; Kedishvili, Natalia Y

    2007-05-01

    Allopregnanolone (ALLO) and androsterone (ADT) are naturally occurring 3alpha-hydroxysteroids that act as positive allosteric regulators of gamma-aminobutyric acid type A receptors. In addition, ADT activates nuclear farnesoid X receptor and ALLO activates pregnane X receptor. At least with respect to gamma-aminobutyric acid type A receptors, the biological activity of ALLO and ADT depends on the 3alpha-hydroxyl group and is lost upon its conversion to either 3-ketosteroid or 3beta-hydroxyl epimer. Such strict structure-activity relationships suggest that the oxidation or epimerization of 3alpha-hydroxysteroids may serve as physiologically relevant mechanisms for the control of the local concentrations of bioactive 3alpha-hydroxysteroids. The exact enzymes responsible for the oxidation and epimerization of 3alpha-hydroxysteroids in vivo have not yet been identified, but our previous studies showed that microsomal nicotinamide adenine dinucleotide-dependent short-chain dehydrogenases/reductases (SDRs) with dual retinol/sterol dehydrogenase substrate specificity (RoDH-like group of SDRs) can oxidize and epimerize 3alpha-hydroxysteroids in vitro. Here, we present the first evidence that microsomal nicotinamide adenine dinucleotide-dependent 3alpha-hydroxysteroid dehydrogenase/epimerase activities are widely distributed in human tissues with the highest activity levels found in liver and testis and lower levels in lung, spleen, brain, kidney, and ovary. We demonstrate that RoDH-like SDRs contribute to the oxidation and epimerization of ALLO and ADT in living cells, and show that RoDH enzymes are expressed in tissues that have microsomal 3alpha-hydroxysteroid dehydrogenase/epimerase activities. Together, these results provide further support for the role of RoDH-like SDRs in human metabolism of 3alpha-hydroxysteroids and offer a new insight into the enzymology of ALLO and ADT inactivation.

  18. 21 CFR 862.1670 - Sorbitol dehydrogenase test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Systems § 862.1670 Sorbitol dehydrogenase test system. (a) Identification. A sorbitol dehydrogenase test system is a device intended to measure the activity of the enzyme sorbitol dehydrogenase in serum... cirrhosis or acute hepatitis. (b) Classification. Class I (general controls). The device is exempt from the...

  19. Calcium signaling in brain mitochondria: interplay of malate aspartate NADH shuttle and calcium uniporter/mitochondrial dehydrogenase pathways.

    PubMed

    Contreras, Laura; Satrústegui, Jorgina

    2009-03-13

    Ca2+ signaling in mitochondria has been mainly attributed to Ca2+ entry to the matrix through the Ca2+ uniporter and activation of mitochondrial matrix dehydrogenases. However, mitochondria can also sense increases in cytosolic Ca2+ through a mechanism that involves the aspartate-glutamate carriers, extramitochondrial Ca2+ activation of the NADH malate-aspartate shuttle (MAS). Both pathways are linked through the shared substrate alpha-ketoglutarate (alphaKG). Here we have studied the interplay between the two pathways under conditions of Ca2+ activation. We show that alphaKG becomes limiting when Ca2+ enters in brain or heart mitochondria, but not liver mitochondria, resulting in a drop in alphaKG efflux through the oxoglutarate carrier and in a drop in MAS activity. Inhibition of alphaKG efflux and MAS activity by matrix Ca2+ in brain mitochondria was fully reversible upon Ca2+ efflux. Because of their differences in cytosolic calcium concentration requirements, the MAS and Ca2+ uniporter-mitochondrial dehydrogenase pathways are probably sequentially activated during a Ca2+ transient, and the inhibition of MAS at the center of the transient may provide an explanation for part of the increase in lactate observed in the stimulated brain in vivo.

  20. Analysis of production responses to changing crude protein levels in lactating dairy cow diets when evaluated in continuous or change-over experimental designs

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate by meta-analysis the effect of experimental design on the production response functions obtained when changing crude protein levels in lactating dairy cow diets. The final database of studies that met the selection criteria contained 55 publications with 2...

  1. Cerebral blood flow changes during sodium-lactate-induced panic attacks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stewart, R.S.; Devous, M.D. Sr.; Rush, A.J.

    1988-04-01

    Dynamic single-photon emission computed axial tomography (CAT) with inhaled xenon-133 was used to measure regional cerebral blood flow in 10 drug-free patients with DSM-III-diagnosed panic disorder and in five normal control subjects. All subjects underwent regional cerebral blood flow studies while at rest or during normal saline infusion and during sodium lactate infusion. Six of the 10 patients and none of the control subjects experienced lactate-induced panic attacks. Lactate infusion markedly raised hemispheric blood flow levels in both control subjects and patients who did not panic. Patients who did panic experienced either a minimal increase or a decrease in hemisphericmore » blood flow.« less

  2. Prognostic Value of Serum Lactate Levels in Patients Undergoing Urgent Heart Transplant: A Subanalysis of the ASIS-TC Spanish Multicenter Study.

    PubMed

    Couto-Mallón, David; González-Vílchez, Francisco; Almenar-Bonet, Luis; Díaz-Molina, Beatriz; Segovia-Cubero, Javier; González-Costello, José; Delgado-Jiménez, Juan; Castel-Lavilla, María A; Crespo-Leiro, María G; Rangel-Sousa, Diego; Martínez-Sellés, Manuel; Rábago-Juan-Aracil, Gregorio; De-la-Fuente-Galán, Luis; Blasco-Peiró, Teresa; Hervás-Sotomayor, Daniela; Garrido-Bravo, Iris P; Mirabet-Pérez, Sonia; Muñiz, Javier; Barge-Caballero, Eduardo

    2018-05-30

    To study the prognostic value of serum lactate in patients under temporary preoperative mechanical circulatory support who underwent urgent heart transplant. We conducted a subanalysis of a Spanish multicenter registry recording data on patients under temporary mechanical circulatory support listed for highly urgent heart transplant from 2010 to 2015. Participants selected for the present study were those who received a transplant and who had known preoperative serum lactate levels. The main study outcome was 1-year survival after transplant. A total of 177 heart transplant recipients were studied; preoperatively, 90 were supported on venoarterial extracorporeal membrane oxygenation, 51 on temporary left ventricular assist devices, and 36 on temporary biventricular assist devices. Preoperative hyperlactatemia (≥ 2 mmol/L) was present in 44 (25%) patients. On multivariable analysis, pretransplant serum lactate was identified as an independent predictor of 1-year posttransplant survival (adjusted HR per 0.1 mmol/L, 1.02; 95%CI, 1.01-1.03; P = .007). One-year posttransplant survival was 53.1% (95%CI, 45.3-60.9) in patients with preoperative hyperlactatemia and 75.6% (95%CI, 71.8-79.4) in those without preoperative hyperlactatemia (adjusted HR, 1.94; 95%CI, 1.04-3.63; P = .039). Preoperative hyperlactatemia correlated with adverse outcomes in patients supported with extracorporeal membrane oxygenation, but not in patients supported on ventricular assist devices. Preoperative serum lactate is a strong independent predictor of worse outcomes in patients undergoing urgent heart transplant on short-term mechanical circulatory support. Copyright © 2018 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  3. Reliability of the Lactate Scout point-of-care instrument for the determination of blood L-lactate concentration in sheep.

    PubMed

    Kaynar, Ozgur; Karapinar, Tolga; Hayirli, Armagan; Baydar, Ersoy

    2015-12-01

    Data on accuracy and precision of the Lactate Scout point-of-care (POC) analyzer in ovine medicine are lacking. The purpose of the study was to assess the reliability of the Lactate Scout in sheep. Fifty-seven sheep at varying ages with various diseases were included. Blood lactate concentration in samples collected from the jugular vein was measured immediately on the Lactate Scout. Plasma L-lactate concentration was measured by the Cobas autoanalyzer as the reference method. Data were subjected to Student's t-test, Passing-Bablok regression, and Bland-Altman plot analyses for comparison and assessment of accuracy, precision, and reliability. Plasma l-lactate concentration was consistently lower than blood L-lactate concentration (3.06 ± 0.24 vs 3.3 ± 0.3 mmol/L, P < .0001). There was a positive correlation between plasma and blood L-lactate concentrations (r = .98, P < .0001). The Lactate Scout had 99% accuracy and 98% precision with the reference method. Blood (Y) and plasma (X) L-lactate concentrations were fitted to Y = 0.28 + 1.00 · X, with a residual standard deviation of 0.31 and a negligible deviation from the identity line (P = .93). The bias was fitted to Y = 0.10 + 0.05 · X, with Sy.x of 0.44 (P < .07). The Lactate Scout has high accuracy and precision, with a negligible bias. It is a reliable POC analyzer to assess L-lactate concentration in ovine medicine. © 2015 American Society for Veterinary Clinical Pathology.

  4. Effects of different sources and levels of dietary gossypol on gossypol residues in plasma and milk of lactating cows.

    PubMed

    Wang, A P; Zhang, J M; Meng, Y L; Deng, L Q; Lv, Y F; Li, C; Wang, J Q

    2012-09-01

    Free gossypol residues in tissues or milk from feeding whole cottonseed and cottonseed meal were measured for their effect on health of dairy cows and humans. Forty lactating cows were randomly assigned to 5 treatments in a 60-d experiment to investigate the effects of sources and dietary level of gossypol on plasma and milk gossypol concentrations in lactating cows. Five experimental diets had identical net energy for lactation and crude protein content on a dry matter (DM) basis. Soybean meal was the main protein ingredient used in the control diet. Cottonseed meal (CSM) or whole cottonseed (WCS) substituted for part of the soybean meal in the other 4 diets. Gossypol levels in the 5 diets were 0 (control), 91.15 mg/kg of DM in CSM1, 117.31mg/kg of DM in CSM2, 385.43 mg/kg of DM in WCS1, and 611.13 mg/kg in WCS2. Yields of 3.5% fat-corrected milk were significantly higher for cows in the WCS2 group; cows in the CSM1 and WCS1 groups showed no differences but both were numerically higher than the control and CSM2 groups. Milk protein concentration was lower for cows consuming WCS1 compared with the control group. Lactose concentration was lower for cows in the CSM2 group compared with the WCS2 group, but no differences were observed among other diets. Aspartate aminotransferase in serum was significantly higher for the WCS2 group compared with the control and WCS1 groups, but no difference was observed with the CSM1 and CSM2 groups. Concentrations of gossypol in plasma and milk of cows in the WCS1 and WCS2 groups were both higher than those of the other groups. No adverse effects were observed on cows fed diets containing 12.0% CSM, and no gossypol was found in plasma and milk. When WCS comprised 15% of the diet DM, yields of 3.5% fat-corrected milk were increased in cows and gossypol was detected in plasma and milk but not at harmful levels. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Lactate in the brain of the freely moving rat: voltammetric monitoring of the changes related to the sleep-wake states.

    PubMed

    Shram, Nataliya; Netchiporouk, Larissa; Cespuglio, Raymond

    2002-08-01

    Cortical lactate was monitored voltammetrically in freely moving rats equipped with polygraphic electrodes. Differential normal pulse voltammetric measurements were carried out using a lactate biosensor coated with lactate oxidase and cellulose acetate. Changes occurring in lactate level were in keeping with sleep-wake states. During slow wave sleep (SWS), the lactate level decreased significantly (-16.2%) vs. the spontaneous waking state (W) referenced to as 100%. During paradoxical sleep (PS), and still vs. W, it remained low (-9.0%) but this variation was not statistically significant. However, when this PS change was compared to the SWS variation, a significant increase in lactate level was then revealed (+8.5%). Finally, during the active waking (aW) triggered by a water puff stress, lactate level rose significantly in accordance with the animal activity (+53% compared to W). Long-term monitoring also allowed the determination of a circadian component in lactate production, the lowest and highest values being monitored during light and dark periods, respectively. The acrophasis of the circadian change occurred during the dark period, about 3 h after the light-off (+89%). It is suggested that during wakefulness astrocyte metabolism allows the transformation of the blood-borne glucose into lactate. The increase in this substrate observed during PS may fulfil the oxidative phosphorylation in order to supply the important ATP need of PS.

  6. The lactate paradox revisited in lowlanders during acclimatization to 4100 m and in high-altitude natives

    PubMed Central

    van Hall, G; Lundby, C; Araoz, M; Calbet, J A L; Sander, M; Saltin, B

    2009-01-01

    Chronic hypoxia has been proposed to induce a closer coupling in human skeletal muscle between ATP utilization and production in both lowlanders (LN) acclimatizing to high altitude and high-altitude natives (HAN), linked with an improved match between pyruvate availability and its use in mitochondrial respiration. This should result in less lactate being formed during exercise in spite of the hypoxaemia. To test this hypothesis six LN (22–31 years old) were studied during 15 min warm up followed by an incremental bicycle exercise to exhaustion at sea level, during acute hypoxia and after 2 and 8 weeks at 4100 m above sea level (El Alto, Bolivia). In addition, eight HAN (26–37 years old) were studied with a similar exercise protocol at altitude. The leg net lactate release, and the arterial and muscle lactate concentrations were elevated during the exercise in LN in acute hypoxia and remained at this higher level during the acclimatization period. HAN had similar high values; however, at the moment of exhaustion their muscle lactate, ADP and IMP content and Cr/PCr ratio were higher than in LN. In conclusion, sea-level residents in the course of acclimatization to high altitude did not exhibit a reduced capacity for the active muscle to produce lactate. Thus, the lactate paradox concept could not be demonstrated. High-altitude natives from the Andes actually exhibit a higher anaerobic energy production than lowlanders after 8 weeks of acclimatization reflected by an increased muscle lactate accumulation and enhanced adenine nucleotide breakdown. PMID:19139048

  7. Blockade of P-Glycoprotein Decreased the Disposition of Phenformin and Increased Plasma Lactate Level.

    PubMed

    Choi, Min-Koo; Song, Im-Sook

    2016-03-01

    This study aimed to investigate the in vivo relevance of P-glycoprotein (P-gp) in the pharmacokinetics and adverse effect of phenformin. To investigate the involvement of P-gp in the transport of phenformin, a bi-directional transport of phenformin was carried out in LLC-PK1 cells overexpressing P-gp, LLC-PK1-Pgp. Basal to apical transport of phenformin was 3.9-fold greater than apical to basal transport and became saturated with increasing phenformin concentration (2-75 μM) in LLC-PK1-Pgp, suggesting the involvement of P-gp in phenformin transport. Intrinsic clearance mediated by P-gp was 1.9 μL/min while passive diffusion clearance was 0.31 μL/min. Thus, P-gp contributed more to phenformin transport than passive diffusion. To investigate the contribution of P-gp on the pharmacokinetics and adverse effect of phenformin, the effects of verapamil, a P-gp inhibitor, on the pharmacokinetics of phenformin were also examined in rats. The plasma concentrations of phenformin were increased following oral administration of phenformin and intravenous verapamil infusion compared with those administerd phenformin alone. Pharmacokinetic parameters such as Cmax and AUC of phenformin increased and CL/F and Vss/F decreased as a consequence of verapamil treatment. These results suggested that P-gp blockade by verapamil may decrease the phenformin disposition and increase plasma phenformin concentrations. P-gp inhibition by verapamil treatment also increased plasma lactate concentration, which is a crucial adverse event of phenformin. In conclusion, P-gp may play an important role in phenformin transport process and, therefore, contribute to the modulation of pharmacokinetics of phenformin and onset of plasma lactate level.

  8. Blockade of P-Glycoprotein Decreased the Disposition of Phenformin and Increased Plasma Lactate Level

    PubMed Central

    Choi, Min-Koo; Song, Im-Sook

    2016-01-01

    This study aimed to investigate the in vivo relevance of P-glycoprotein (P-gp) in the pharmacokinetics and adverse effect of phenformin. To investigate the involvement of P-gp in the transport of phenformin, a bi-directional transport of phenformin was carried out in LLC-PK1 cells overexpressing P-gp, LLC-PK1-Pgp. Basal to apical transport of phenformin was 3.9-fold greater than apical to basal transport and became saturated with increasing phenformin concentration (2–75 μM) in LLC-PK1-Pgp, suggesting the involvement of P-gp in phenformin transport. Intrinsic clearance mediated by P-gp was 1.9 μL/min while passive diffusion clearance was 0.31 μL/min. Thus, P-gp contributed more to phenformin transport than passive diffusion. To investigate the contribution of P-gp on the pharmacokinetics and adverse effect of phenformin, the effects of verapamil, a P-gp inhibitor, on the pharmacokinetics of phenformin were also examined in rats. The plasma concentrations of phenformin were increased following oral administration of phenformin and intravenous verapamil infusion compared with those administerd phenformin alone. Pharmacokinetic parameters such as Cmax and AUC of phenformin increased and CL/F and Vss/F decreased as a consequence of verapamil treatment. These results suggested that P-gp blockade by verapamil may decrease the phenformin disposition and increase plasma phenformin concentrations. P-gp inhibition by verapamil treatment also increased plasma lactate concentration, which is a crucial adverse event of phenformin. In conclusion, P-gp may play an important role in phenformin transport process and, therefore, contribute to the modulation of pharmacokinetics of phenformin and onset of plasma lactate level. PMID:26797108

  9. Relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against Neospora caninum infection in different stages of lactation

    PubMed

    Alekish, Myassar O.; Talafha, Abdelsalam Q; Alshehabat, Musa A; Ismail, Zuhair A Bani

    Neospora caninum is an important cause of abortion in dairy cattle. The general health of affected cows has not been investigated before. Therefore, the main objective of this study was to identify possible relationships between certain metabolic diseases and selected serum biochemical parameters in seropositive dairy cows against N. caninum antibodies in different stages of lactation. The study was carried out using 72 N. caninum seropositive cows and 61 seronegative dairy cows (control). Serum from all cows was tested to determine their N. caninum status (seropositive vs seronegative) using commercially available indirect enzyme-linked immunosorbent assay test kit (iELISA). In addition, serum biochemical parameters including beta-hydroxybutyrate (BHB), glucose, creatinine, blood urea nitrogen, total protein, albumin, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) and gamma-glutamyltranspeptidase (GGT) were determined using routine laboratory methods. The stage of lactation was obtained at the time of sampling from farm records. Student independent t-test showed that there was a significant difference in the serum concentrations of BHB, AST, ALT, and LDH between seropositive and seronegative cows. There was no significant association between seropositivity and the stage of lactation. However, multivariable logistic regression analysis showed that there was a strong association between seropositivity and BHB concentrations. Results of this study indicate a possible relationship between N. caninum seropositivity and certain metabolic diseases such as ketosis and fatty liver syndrome in dairy cows.

  10. Acute mercury exposition of virgin, pregnant, and lactating rats: Histopathological kidney and liver evaluations.

    PubMed

    Oliveira, Vitor Antunes; Favero, Gaia; Stacchiotti, Alessandra; Giugno, Lorena; Buffoli, Barbara; de Oliveira, Claudia Sirlene; Lavazza, Antonio; Albanese, Massimo; Rodella, Luigi Fabrizio; Pereira, Maria Ester; Rezzani, Rita

    2017-05-01

    This work investigated the effects of mercury chloride (HgCl 2 ) acute exposure on virgin, pregnant and lactating rats by determination of renal and hepatic morphological and ultrastructural parameters and the expression of oxidative stress and stress tolerance markers, due to kidney and liver are the organs that more accumulate inorganic mercury. Adult Wistar rats virgin (90 days old), pregnant (18 th gestation day) and lactating (7 th lactation day) were injected once with HgCl 2 (5 mg/kg) or saline (controls). We observed that HgCl 2 exposure of virgin rats caused significant inflammatory infiltration and severe morphological variations, like glomeruli atrophy, dilatation of Bowman's capsule, tubular degeneration and hepatocytes alteration. Moreover, virgin rats presented mitochondrial modification, important oxidative stress and increase in stress tolerance proteins at both kidney and liver level, compared with virgin controls. In detail, virgin rats exposed to HgCl 2 presented significantly elevated level of inducible nitric oxide synthase, heat shock protein 27 and glucose regulated proteins 75 expressions at both renal tubular and hepatocytes level, respect untreated virgin rats. Interestingly, pregnant and lactating rats exposed to HgCl 2 presented weak renal and liver morphological alterations, showing weak inflammatory infiltration and no significant difference in structural mitochondrial transmembrane protein, oxidative stress markers and stress tolerance proteins expressions respect controls (virgin, pregnant and lactating rats). Although, both control and HgCl 2 -exposed pregnant and lactating rats showed renal glomeruli greater in diameter respect virgin rats. In conclusion, we believe that virgin rats are more sensitive to HgCl 2 toxicity respect pregnant and lactating rats. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1500-1512, 2017. © 2016 Wiley Periodicals, Inc.

  11. Glutamate Dehydrogenase from Apodachlya (Oomycetes) 1

    PubMed Central

    Price, Jeffrey S.; Gleason, Frank H.

    1972-01-01

    A glutamate dehydrogenase specific for nicotinamide-adenine-dinucleotide has been purified 50-fold from Apodachlya brachynema (Leptomitales). Certain physical, chemical, and kinetic properties of this enzyme have been studied, particularly specificity for coenzymes and substrates. With glucose as the sole carbon source, the synthesis of glutamate dehydrogenase was repressed, whereas glutamate, proline, alanine, or ornithine plus aspartate as sole carbon sources induced synthesis of the enzyme. These data indicate that the function of this enzyme is primarily degradative, although there is no evidence for a nicotinamide-adenine-dinucleotide-phosphate-specific biosynthetic glutamate dehydrogenase in Apodachlya. PMID:16657902

  12. The metabolic trinity, glucose-glycogen-lactate, links astrocytes and neurons in brain energetics, signaling, memory, and gene expression.

    PubMed

    Dienel, Gerald A

    2017-01-10

    Glucose, glycogen, and lactate are traditionally identified with brain energetics, ATP turnover, and pathophysiology. However, recent studies extend their roles to include involvement in astrocytic signaling, memory consolidation, and gene expression. Emerging roles for these brain fuels and a readily-diffusible by-product are linked to differential fluxes in glycolytic and oxidative pathways, astrocytic glycogen dynamics, redox shifts, neuron-astrocyte interactions, and regulation of astrocytic activities by noradrenaline released from the locus coeruleus. Disproportionate utilization of carbohydrate compared with oxygen during brain activation is influenced by catecholamines, but its physiological basis is not understood and its magnitude may be affected by technical aspects of metabolite assays. Memory consolidation and gene expression are impaired by glycogenolysis blockade, and prevention of these deficits by injection of abnormally-high concentrations of lactate was interpreted as a requirement for astrocyte-to-neuron lactate shuttling in memory and gene expression. However, lactate transport was not measured and evidence for presumed shuttling is not compelling. In fact, high levels of lactate used to preserve memory consolidation and induce gene expression are sufficient to shut down neuronal firing via the HCAR1 receptor. In contrast, low lactate levels activate a receptor in locus coeruleus that stimulates noradrenaline release that may activate astrocytes throughout brain. Physiological relevance of exogenous concentrations of lactate used to mimic and evaluate metabolic, molecular, and behavioral effects of lactate requires close correspondence with the normal lactate levels, the biochemical and cellular sources and sinks, and specificity of lactate delivery to target cells. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Fibroblast growth factor 8 is expressed at higher levels in lactating human breast and in breast cancer.

    PubMed

    Zammit, C; Coope, R; Gomm, J J; Shousha, S; Johnston, C L; Coombes, R C

    2002-04-08

    Fibroblast growth factor 8 can transform NIH3T3 cells and its expression has been found to be associated with breast and prostate cancer. Following our finding that fibroblast growth factor 8 mRNA expression is increased in breast cancer, we have undertaken an immunohistochemistry study of fibroblast growth factor 8 expression in a series of human breast tissues and other normal tissues. Our findings confirm increased expression of fibroblast growth factor 8 in malignant breast tissue but also show significant fibroblast growth factor 8 expression in non-malignant breast epithelial cells. No significant difference in fibroblast growth factor 8 expression was found between different grades of ductal carcinoma, lobular carcinoma and ductal carcinoma in-situ or cancer of different oestrogen receptor, progesterone receptor or nodal status. The highest levels of fibroblast growth factor 8 expression were found in lactating breast tissues and fibroblast growth factor 8 was also detected in human milk. A survey of other normal tissues showed that fibroblast growth factor 8 is expressed in the proliferative cells of the dermis and epithelial cells in colon, ovary fallopian tube and uterus. Fibroblast growth factor 8 appears to be expressed in several organs in man and appears to have an importance in lactation.

  14. The demands of lactation promote differential regulation of lipid stores in fasting elephant seals.

    PubMed

    Fowler, Melinda A; Debier, Cathy; Champagne, Cory D; Crocker, Daniel E; Costa, Daniel P

    2016-01-01

    Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northern elephant seals regulate the mobilization of lipid reserves and subsequently milk lipid content during lactation. We sampled 36 females early and 39 at the end of lactation. To determine the separate influences of lactation from fasting, we also sampled fasting but non-lactating females early and late (8 and 6 seals, respectively) in their molting fasting period. Mass and adiposity were measured, as well as circulating non-esterified fatty acid (NEFA), triacylglycerol (TAG), cortisol, insulin and growth hormone levels. Milk was collected from lactating females. Milk lipid content increased from 31% in early to 51% in late lactation. In lactating females plasma NEFA was positively related to cortisol and negatively related to insulin, but in molting seals, only variation in cortisol was related to NEFA. Milk lipid content varied with mass, adiposity, NEFA, TAG, cortisol and insulin. Surprisingly, growth hormone concentration was not related to lipid metabolites or milk lipid. Suppression of insulin release appears to be the differential regulator of lipolysis in lactating versus molting seals, facilitating mobilization of stored lipids and maintenance of high NEFA concentrations for milk synthesis. Milk lipid was strongly impacted by the supply of substrate to the mammary gland, indicating regulation at the level of mobilization of lipid reserves. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Xylitol dehydrogenase from Candida tropicalis: molecular cloning of the gene and structural analysis of the protein.

    PubMed

    Lima, Luanne Helena Augusto; Pinheiro, Cristiano Guimarães do Amaral; de Moraes, Lídia Maria Pepe; de Freitas, Sonia Maria; Torres, Fernando Araripe Gonçalves

    2006-12-01

    Yeasts can metabolize xylose by the action of two key enzymes: xylose reductase and xylitol dehydrogenase. In this work, we present data concerning the cloning of the XYL2 gene encoding xylitol dehydrogenase from the yeast Candida tropicalis. The gene is present as a single copy in the genome and is controlled at the transcriptional level by the presence of the inducer xylose. XYL2 was functionally tested by heterologous expression in Saccharomyces cerevisiae to develop a yeast strain capable of producing ethanol from xylose. Structural analysis of C. tropicalis xylitol dehydrogenase, Xyl2, suggests that it is a member of the medium-chain dehydrogenase (MDR) family. This is supported by the presence of the amino acid signature [GHE]xx[G]xxxxx[G]xx[V] in its primary sequence and a typical alcohol dehydrogenase Rossmann fold pattern composed by NAD(+) and zinc ion binding domains.

  16. Lactation Induction in a Commissioned Mother by Surrogacy: Effects on Prolactin Levels, Milk Secretion and Mother Satisfaction.

    PubMed

    Zingler, Emilie; Amato, Angélica Amorim; Zanatta, Alysson; Vogt, Maria de Fátima Brito; Wanderley, Miriam da Silva; Mariani Neto, Coríntio; Zaconeta, Alberto Moreno

    2017-02-01

    Case report of a 39-year-old intended mother of a surrogate pregnancy who underwent induction of lactation by sequential exposure to galactagogue drugs (metoclopramide and domperidone), nipple mechanical stimulation with an electric pump, and suction by the newborn. The study aimed to analyze the effect of each step of the protocol on serum prolactin levels, milk secretion and mother satisfaction, in the set of surrogacy. Serum prolactin levels and milk production had no significant changes. Nevertheless, the mother was able to breastfeed for four weeks, and expressed great satisfaction with the experience. As a conclusion, within the context of a surrogate pregnancy, breastfeeding seems to bring emotional benefits not necessarily related to an increase in milk production. Thieme-Revinter Publicações Ltda Rio de Janeiro, Brazil.

  17. Effect of blood glucose level on acute stress response of grass carp Ctenopharyngodon idella.

    PubMed

    Jiang, Danli; Wu, Yubo; Huang, Di; Ren, Xing; Wang, Yan

    2017-10-01

    Stress has a considerable impact on welfare and productivity of fish, and blood glucose level of fish may be a factor modulating stress response. This study evaluated the effect of blood glucose level and handling on acute stress response of grass carp Ctenopharyngodon idella. Fish were intraperitoneally injected with glucose at 0, 0.2, 0.5, and 1.0 mg g -1 body mass (BM) and then were exposed to handling for 5 min. Glucose injection resulted in increase of plasma glucose level and liver glycogen content and decrease of plasma lactate level. Handling resulted in increase of plasma levels of cortisol, glucose, and lactate and plasma lactic dehydrogenase (LDH) activity and decrease of liver glycogen content. At 1 h post-stress, the plasma cortisol level was lower in the stressed fish injected with glucose at 0.5 mg g -1 BM than the stressed fish injected with glucose at 0, 0.2, and 1.0 mg g -1 BM. No significant differences were found in the activities of phosphoenolpyruvate carboxykinase (PEPCK) and pyruvate kinase (PK) in the liver between the stressed and unstressed fish, regardless of the dose of glucose injection. At 1 h post-stress, the liver glucose-6-phosphatase (G6Pase) activity was higher in the fish without glucose injection than in the fish injected with glucose. This study reveals that blood glucose level can affect stress response of grass carp by modulating cortisol release and glucose homeostasis through glycogen metabolism and gluconeogenesis in the liver.

  18. Arterial versus venous lactate: a measure of sepsis in children.

    PubMed

    Samaraweera, Sahan Asela; Gibbons, Berwyck; Gour, Anami; Sedgwick, Philip

    2017-08-01

    This study assessed the agreement between arterial and venous blood lactate and pH levels in children with sepsis. This retrospective, three-year study involved 60 PICU patients, with data collected from electronic or paper patient records. The inclusion criteria comprised of children (≤17 years old) with sepsis and those who had a venous blood gas taken first with an arterial blood gas taken after within one hour. The lactate and pH values measured through each method were analysed. There is close agreement between venous and arterial lactate up to 2 mmol/L. As this value increases, this agreement becomes poor. The limits of agreement (LOA) are too large (±1.90 mmol/L) to allow venous and arterial lactate to be used interchangeably. The mean difference and LOA between both methods would be much smaller if derived using lactate values under 2.0 mmol/L. There is close agreement between arterial and venous pH (MD = -0.056, LOA ± 0.121). However, due to extreme variations in pH readings during sepsis, pH alone is an inadequate marker. A venous lactate ≤2 mmol/L can be used as a surrogate for arterial lactate during early management of sepsis in children. However, if the value exceeds 2 mmol/L, an arterial sample must confirm the venous result. What is known: • In children with septic shock, a blood gas is an important test to show the presence of acidosis and high lactic acid. Hyperlactataemia on admission is an early predictor of outcome and is associated with a greater mortality risk. • An arterial sample is the standard for lactate measurement, however getting a sample may be challenging in the emergency department or a general paediatric ward. Venous samples are quicker and easier to obtain. Adult studies generally advise caution in replacing venous lactate values for the arterial standard, whilst paediatric studies are limited in this area. What is new: • This is the first study assessing the agreement between arterial and peripheral venous

  19. Blood lactate concentration at selected of olympic modes weightlifting.

    PubMed

    Gupta, S; Goswami, A

    2001-04-01

    This study highlights the blood lactate response of weightlifters (N = 5) in two modes of olympic lifts: Snatch (SN) and Clean & Jerk (CJ), during three types of training namely (1) one repetition lift (ORL), (2) Multiple set session (MSS) and (3) one set session (OSS). In ORL, 30, 40, 50, and 60 kg, each of one repetition only, were lifted with an interval of 5 min between two consecutive loads. Both MSS and OSS consisted of 6 sets of lift: 50% x 6 (i.e. 50% of 1 Repetition Maximum x 6 repetitions), 60% x 5, 70% x 4, 80% x 3, 90% x 2, and 100% x 1. In MSS, 3 to 3.5 min interval was given between two successive sets whereas in OSS the interval was approximately 24 hours. Lactate levels were very low (< 3.5 mM) in ORL. In MSS, lactate reached peak at an intermediate set, but, it was maximum at the first set and then declined gradually in OSS. In most of the cases, however, lactate were significantly higher in CJ than SN. The study concludes that: (a) anaerobic glycolysis is not stimulated considerably when the lifting time is only 4-5 sec, (b) repetition of lift plays more important role, than intensity, in lactate production, (c) CJ is more strenuous than SN for a given %RM.

  20. Evidence of In Vivo Absorption of Lactate and Modulation of Short Chain Fatty Acid Absorption from the Reticulorumen of Non-Lactating Cattle Fed High Concentrate Diets.

    PubMed

    Qumar, Muhammad; Khiaosa-Ard, Ratchaneewan; Pourazad, Poulad; Wetzels, Stefanie U; Klevenhusen, Fenja; Kandler, Wolfgang; Aschenbach, Jörg R; Zebeli, Qendrim

    2016-01-01

    Short-chain fatty acids (SCFAs) and lactate are endproducts of rumen fermentation and important energy sources for the host ruminant. Because their rapid accumulation results in ruminal acidosis, enhancement of the absorption of SCFA and lactate across reticuloruminal wall is instrumental in increasing energy supply and preventing ruminal acidosis in cattle. This study investigated whether the reticuloruminal absorption of SCFAs and lactate was altered by different strategies of high concentrate feeding. Eight rumen-cannulated, non-lactating Holstein cows were fed a forage-only diet (baseline) and then gradually adapted over 6 d to a 60% concentrate level. Thereafter, this concentrate-rich diet was fed for 4 wk either continuously (Con; n = 8) or interruptedly (Int; n = 8). Absorption of SCFAs and lactate was determined in vivo from the experimental buffer introduced into the washed reticulorumen. The buffer contained acetate, propionate, butyrate and lactate at a concentration of 60, 30, 10 and 5 mmol/L, respectively and Cr-EDTA as a marker for correcting ruminal water fluxes. The reticuloruminal absorption after 35 and 65 min of buffer incubation was measured at the baseline, after 1 wk of 60% concentrate feeding in the interrupted model (Int-1) and after 4 wk of concentrate feeding in both feeding models (Int-4 and Con-4). Data showed that the absorption rates of individual and total SCFAs during the first 35 min of incubation of Con-4 were highest (~1.7 times compared to baseline), while Int-1 and Int-4 were similar to respective baseline. Lactate was not absorbed during forage-only baseline and 1-wk concentrate feeding, but after 4-wk feeding of concentrates in both models. In conclusion, SCFAs absorption across the reticulorumen of non-lactating cattle was enhanced by the 4-wk continuous concentrate feeding, which seems to be more advantageous in terms of rumen acidosis prevention compared to the interrupted feeding model. The study provides evidence of