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Sample records for affects glycogen accumulation

  1. Survival strategies of polyphosphate accumulating organisms and glycogen accumulating organisms under conditions of low organic loading.

    Science.gov (United States)

    Carvalheira, Mónica; Oehmen, Adrian; Carvalho, Gilda; Reis, Maria A M

    2014-11-01

    Enhanced biological phosphorus removal (EBPR) is usually limited by organic carbon availability in wastewater treatment plants (WWTPs). Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were operated under extended periods with low organic carbon loading in order to examine its impact on their activity and survival. The decrease in organic carbon load affected PAOs and GAOs in different ways, where the biomass decay rate of GAOs was approximately 4times higher than PAOs. PAOs tended to conserve a relatively high residual concentration of polyhydroxyalkanoates (PHAs) under aerobic conditions, while GAOs tended to deplete their available PHA more rapidly. This slower oxidation rate of PHA by PAOs at residual concentration levels enabled them to maintain an energy source for aerobic maintenance processes for longer than GAOs. This may provide PAOs with an advantage over GAOs in surviving the low organic loading conditions commonly found in full-scale wastewater treatment plants. PMID:25270044

  2. The Competition between Polyphosphate-Accumulating Organisms and Glycogen-Accumulating Organisms: Temperature Effects and Modelling

    OpenAIRE

    López Vázquez, C.M.

    2009-01-01

    Due to relatively high phosphorus removal efficiency and economy, the enhanced biological phosphorus removal (EBPR) in activated sludge wastewater treatment systems is a widely applied process to control and prevent eutrophication in surface water bodies. However, the EBPR process can be prone to suffer of upsets and deterioration. Since glycogen-accumulating organisms (GAO) compete with polyphosphate-accumulating organisms (PAO), which are the microorganisms that perform the biological phosp...

  3. Adipose tissue glycogen accumulation is associated with obesity-linked inflammation in humans

    Science.gov (United States)

    Ceperuelo-Mallafré, Victòria; Ejarque, Miriam; Serena, Carolina; Duran, Xavier; Montori-Grau, Marta; Rodríguez, Miguel Angel; Yanes, Oscar; Núñez-Roa, Catalina; Roche, Kelly; Puthanveetil, Prasanth; Garrido-Sánchez, Lourdes; Saez, Enrique; Tinahones, Francisco J.; Garcia-Roves, Pablo M.; Gómez-Foix, Anna Ma; Saltiel, Alan R.; Vendrell, Joan; Fernández-Veledo, Sonia

    2015-01-01

    Objective Glycogen metabolism has emerged as a mediator in the control of energy homeostasis and studies in murine models reveal that adipose tissue might contain glycogen stores. Here we investigated the physio(patho)logical role of glycogen in human adipose tissue in the context of obesity and insulin resistance. Methods We studied glucose metabolic flux of hypoxic human adipoctyes by nuclear magnetic resonance and mass spectrometry-based metabolic approaches. Glycogen synthesis and glycogen content in response to hypoxia was analyzed in human adipocytes and macrophages. To explore the metabolic effects of enforced glycogen deposition in adipocytes and macrophages, we overexpressed PTG, the only glycogen-associated regulatory subunit (PP1-GTS) reported in murine adipocytes. Adipose tissue gene expression analysis was performed on wild type and homozygous PTG KO male mice. Finally, glycogen metabolism gene expression and glycogen accumulation was analyzed in adipose tissue, mature adipocytes and resident macrophages from lean and obese subjects with different degrees of insulin resistance in 2 independent cohorts. Results We show that hypoxia modulates glucose metabolic flux in human adipocytes and macrophages and promotes glycogenesis. Enforced glycogen deposition by overexpression of PTG re-orients adipocyte secretion to a pro-inflammatory response linked to insulin resistance and monocyte/lymphocyte migration. Furthermore, glycogen accumulation is associated with inhibition of mTORC1 signaling and increased basal autophagy flux, correlating with greater leptin release in glycogen-loaded adipocytes. PTG-KO mice have reduced expression of key inflammatory genes in adipose tissue and PTG overexpression in M0 macrophages induces a pro-inflammatory and glycolytic M1 phenotype. Increased glycogen synthase expression correlates with glycogen deposition in subcutaneous adipose tissue of obese patients. Glycogen content in subcutaneous mature adipocytes is associated

  4. Impact of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO).

    Science.gov (United States)

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2014-09-01

    The use of saline water as secondary quality water in urban environments for sanitation is a promising alternative towards mitigating fresh water scarcity. However, this alternative will increase the salinity in the wastewater generated that may affect the biological wastewater treatment processes, such as biological phosphorus removal. In addition to the production of saline wastewater by the direct use of saline water in urban environments, saline wastewater is also generated by some industries. Intrusion of saline water into the sewers is another source of salinity entering the wastewater treatment plant. In this study, the short-term effects of salinity on the anaerobic metabolism of phosphate-accumulating organisms (PAO) and glycogen-accumulating organisms (GAO) were investigated to assess the impact of salinity on enhanced biological phosphorus removal. Hereto, PAO and GAO cultures enriched at a relatively low salinity level (0.02 % W/V) were exposed to salinity concentrations of up to 6 % (as NaCl) in anaerobic batch tests. It was demonstrated that both PAO and GAO are affected by higher salinity levels, with PAO being the more sensitive organisms to the increasing salinity. The maximum acetate uptake rate of PAO decreased by 71 % when the salinity increased from 0 to 1 %, while that of GAO decreased by 41 % for the same salinity increase. Regarding the stoichiometry of PAO, a decrease in the P-release/HAc uptake ratio accompanied with an increase in the glycogen consumption/HAc uptake ratio was observed for PAO when the salinity increased from 0 to 2 % salinity, indicating a metabolic shift from a poly-P-dependent to a glycogen-dependent metabolism. The anaerobic maintenance requirements of PAO and GAO increased as the salinity concentrations risen up to 4 % salinity. PMID:24831025

  5. Glycogen accumulation in alveolar type II cells in 3-methylindole--induced pulmonary edema in goats.

    OpenAIRE

    Atwal, O. S.; Bray, T. M.

    1981-01-01

    The present study shows that intravenous infusion of 3-methylindole (3MI) induced acute pulmonary edema in goats. Edematous changes were seen in the alveoli and the interalveolar interstitium. At 72 hours after treatment, an accumulation of glycogen that had a pathognomonic appearance of alpha particles was observed in the alveolar Type II cells. A rich accumulation of glycogen particles and defective lamellar bodies containing triglycerides were the significant morphologic changes in the alv...

  6. Radiation-Induced Glycogen Accumulation Detected by Single Cell Raman Spectroscopy Is Associated with Radioresistance that Can Be Reversed by Metformin.

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    Quinn Matthews

    Full Text Available Altered cellular metabolism is a hallmark of tumor cells and contributes to a host of properties associated with resistance to radiotherapy. Detection of radiation-induced biochemical changes can reveal unique metabolic pathways affecting radiosensitivity that may serve as attractive therapeutic targets. Using clinically relevant doses of radiation, we performed label-free single cell Raman spectroscopy on a series of human cancer cell lines and detected radiation-induced accumulation of intracellular glycogen. The increase in glycogen post-irradiation was highest in lung (H460 and breast (MCF7 tumor cells compared to prostate (LNCaP tumor cells. In response to radiation, the appearance of this glycogen signature correlated with radiation resistance. Moreover, the buildup of glycogen was linked to the phosphorylation of GSK-3β, a canonical modulator of cell survival following radiation exposure and a key regulator of glycogen metabolism. When MCF7 cells were irradiated in the presence of the anti-diabetic drug metformin, there was a significant decrease in the amount of radiation-induced glycogen. The suppression of glycogen by metformin following radiation was associated with increased radiosensitivity. In contrast to MCF7 cells, metformin had minimal effects on both the level of glycogen in H460 cells following radiation and radiosensitivity. Our data demonstrate a novel approach of spectral monitoring by Raman spectroscopy to assess changes in the levels of intracellular glycogen as a potential marker and resistance mechanism to radiation therapy.

  7. Radiation-Induced Glycogen Accumulation Detected by Single Cell Raman Spectroscopy Is Associated with Radioresistance that Can Be Reversed by Metformin.

    Science.gov (United States)

    Matthews, Quinn; Isabelle, Martin; Harder, Samantha J; Smazynski, Julian; Beckham, Wayne; Brolo, Alexandre G; Jirasek, Andrew; Lum, Julian J

    2015-01-01

    Altered cellular metabolism is a hallmark of tumor cells and contributes to a host of properties associated with resistance to radiotherapy. Detection of radiation-induced biochemical changes can reveal unique metabolic pathways affecting radiosensitivity that may serve as attractive therapeutic targets. Using clinically relevant doses of radiation, we performed label-free single cell Raman spectroscopy on a series of human cancer cell lines and detected radiation-induced accumulation of intracellular glycogen. The increase in glycogen post-irradiation was highest in lung (H460) and breast (MCF7) tumor cells compared to prostate (LNCaP) tumor cells. In response to radiation, the appearance of this glycogen signature correlated with radiation resistance. Moreover, the buildup of glycogen was linked to the phosphorylation of GSK-3β, a canonical modulator of cell survival following radiation exposure and a key regulator of glycogen metabolism. When MCF7 cells were irradiated in the presence of the anti-diabetic drug metformin, there was a significant decrease in the amount of radiation-induced glycogen. The suppression of glycogen by metformin following radiation was associated with increased radiosensitivity. In contrast to MCF7 cells, metformin had minimal effects on both the level of glycogen in H460 cells following radiation and radiosensitivity. Our data demonstrate a novel approach of spectral monitoring by Raman spectroscopy to assess changes in the levels of intracellular glycogen as a potential marker and resistance mechanism to radiation therapy. PMID:26280348

  8. Reduced Muscle Glycogen Differentially Affects Exercise Performance and Muscle Fatigue

    OpenAIRE

    Simon Lees; Williams, Jay H; Batts, Timothy W.

    2013-01-01

    This investigation examined the effects of reduced muscle glycogen on exercise performance and muscle fatigue. Male rats were assigned to a low glycogen group (LG) that participated in a protocol of exercise and fasting, a high glycogen group (HG) that exercised but were allowed free access to food, or control group (CON) that did not exercise but were allowed free access to food. Following the protocol, muscle glycogen content of the LG animals was reduced by 45%. The LG animals also perform...

  9. Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater.

    Science.gov (United States)

    Bengtsson, Simon; Werker, Alan; Welander, Thomas

    2008-01-01

    A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater. PMID:18701781

  10. Community Structure Evolution and Enrichment of Glycogen-Accumulating Organisms Producing Polyhydroxyalkanoates from Fermented Molasses▿

    OpenAIRE

    Pisco, Ana R.; Bengtsson, Simon; Werker, Alan; Reis, Maria A. M.; Lemos, Paulo C.

    2009-01-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteri...

  11. Genetic Manipulation of Glycogen Allocation Affects Replicative Lifespan in E. coli.

    Directory of Open Access Journals (Sweden)

    Alex Boehm

    2016-04-01

    Full Text Available In bacteria, replicative aging manifests as a difference in growth or survival between the two cells emerging from division. One cell can be regarded as an aging mother with a decreased potential for future survival and division, the other as a rejuvenated daughter. Here, we aimed at investigating some of the processes involved in aging in the bacterium Escherichia coli, where the two types of cells can be distinguished by the age of their cell poles. We found that certain changes in the regulation of the carbohydrate metabolism can affect aging. A mutation in the carbon storage regulator gene, csrA, leads to a dramatically shorter replicative lifespan; csrA mutants stop dividing once their pole exceeds an age of about five divisions. These old-pole cells accumulate glycogen at their old cell poles; after their last division, they do not contain a chromosome, presumably because of spatial exclusion by the glycogen aggregates. The new-pole daughters produced by these aging mothers are born young; they only express the deleterious phenotype once their pole is old. These results demonstrate how manipulations of nutrient allocation can lead to the exclusion of the chromosome and limit replicative lifespan in E. coli, and illustrate how mutations can have phenotypic effects that are specific for cells with old poles. This raises the question how bacteria can avoid the accumulation of such mutations in their genomes over evolutionary times, and how they can achieve the long replicative lifespans that have recently been reported.

  12. Genetic Manipulation of Glycogen Allocation Affects Replicative Lifespan in E. coli.

    Science.gov (United States)

    Boehm, Alex; Arnoldini, Markus; Bergmiller, Tobias; Röösli, Thomas; Bigosch, Colette; Ackermann, Martin

    2016-04-01

    In bacteria, replicative aging manifests as a difference in growth or survival between the two cells emerging from division. One cell can be regarded as an aging mother with a decreased potential for future survival and division, the other as a rejuvenated daughter. Here, we aimed at investigating some of the processes involved in aging in the bacterium Escherichia coli, where the two types of cells can be distinguished by the age of their cell poles. We found that certain changes in the regulation of the carbohydrate metabolism can affect aging. A mutation in the carbon storage regulator gene, csrA, leads to a dramatically shorter replicative lifespan; csrA mutants stop dividing once their pole exceeds an age of about five divisions. These old-pole cells accumulate glycogen at their old cell poles; after their last division, they do not contain a chromosome, presumably because of spatial exclusion by the glycogen aggregates. The new-pole daughters produced by these aging mothers are born young; they only express the deleterious phenotype once their pole is old. These results demonstrate how manipulations of nutrient allocation can lead to the exclusion of the chromosome and limit replicative lifespan in E. coli, and illustrate how mutations can have phenotypic effects that are specific for cells with old poles. This raises the question how bacteria can avoid the accumulation of such mutations in their genomes over evolutionary times, and how they can achieve the long replicative lifespans that have recently been reported. PMID:27093302

  13. Enrichment of denitrifying glycogen-accumulating organisms in anaerobic/anoxic activated sludge system.

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    Zeng, Raymond J; Yuan, Zhiguo; Keller, Jürg

    2003-02-20

    Denitrifying glycogen-accumulating organisms (DGAO) were successfully enriched in a lab-scale sequencing batch reactor (SBR) running with anaerobic/anoxic cycles and acetate feeding during the anaerobic period. Acetate was completely taken up anaerobically, which was accompanied by the consumption of glycogen and the production of poly-beta-hydroxy-alkanoates (PHA). In the subsequent anoxic stage, nitrate or nitrite was utilized as electron acceptor for the oxidation of PHA, resulting in glycogen replenishment and cell growth. The above phenotype showed by the enrichment culture demonstrates the existence of DGAO. Further, it was found that the anaerobic behavior of DGAO could be predicted well by the anaerobic GAO model of Filipe et al. (2001) and Zeng et al. (2002a). The final product of denitrification during anoxic stage was mainly nitrous oxide (N(2)O) rather than N(2). The data strongly suggests that N(2)O production may be caused by the inhibition of nitrous oxide reductase by an elevated level of nitrite accumulated during denitrification. The existence of these organisms is a concern in biological nutrient removal systems that typically have an anaerobic/anoxic/aerobic reactor sequence since they are potential competitors to the polyphosphate-accumulating organisms. PMID:12491525

  14. Role of submaximal exercise in promoting creatine and glycogen accumulation in human skeletal muscle.

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    Robinson, T M; Sewell, D A; Hultman, E; Greenhaff, P L

    1999-08-01

    We examined the effect of glycogen-depleting exercise on subsequent muscle total creatine (TCr) accumulation and glycogen resynthesis during postexercise periods when the diet was supplemented with carbohydrate (CHO) or creatine (Cr) + CHO. Fourteen subjects performed one-legged cycling exercise to exhaustion. Muscle biopsies were taken from the exhausted (Ex) and nonexhausted (Nex) limbs after exercise and after 6 h and 5 days of recovery, during which CHO (CHO group, n = 7) or Cr + CHO (Cr+CHO group, n = 7) supplements were ingested. Muscle TCr concentration ([TCr]) was unchanged in both groups 6 h after supplementation commenced but had increased in the Ex (P supercompensation in the exercised muscle. PMID:10444618

  15. Metabolic characteristics of a glycogen-accumulating organism in Defluviicoccus cluster II revealed by comparative genomics.

    Science.gov (United States)

    Wang, Zhiping; Guo, Feng; Mao, Yanping; Xia, Yu; Zhang, Tong

    2014-11-01

    Glycogen-accumulating organisms (GAOs) may compete with phosphate-accumulating organisms (PAOs) for short-chain fatty acids (VFAs) in anaerobic polyhydroxyalkanoates (PHA) synthesis, but no consequently aerobic polyphosphate accumulation in enhanced biological phosphorus removal (EBPR) process, thus deteriorating the EBPR process. They are detected frequently in the deteriorated EBPR process, but their metabolisms are still far from our comprehensions for there is seldom pure culture. In this study, a nearly complete draft genome of a GAOs in Defluviicoccus cluster II, GAO-HK, is recruited from the metagenome of activated sludge in a full-scale industrial anoxic/aerobic wastewater plant. Comparative genomics reveal similar metabolisms of PHA and glycogen in GAOs of GAO-HK, Defluviicoccus tetraformis TFO71 (TFO71) and Competibacter phosphatis clade IIA (CPIIA), and PAOs of Accumulibacter clade IIA UW-1 (UW-1) and Tetrasphaera elongata Lp2 (Lp2). Although there are similar gene cassettes related with polyphosphate metabolism in these GAOs and PAOs, especially for Defluviicoccus-relative bacteria and UW-1, ppk1 in GAOs are diverse from those in the identified PAOs, implying the difference of polyphosphate metabolism in GAOs and PAOs. Additionally, genes related to the dissimilatory denitrification are absent in TFO71 and GAO-HK, implying that additional nitrate or nitrite may favor PAOs over Defluviicoccus-relative GAOs. Therefore, PAOs suffering from competition of Defluviicoccus-relative GAOs might be rescued with the additional nitrate/nitrite, which is important to improve the stability of EBPR processes. PMID:24889288

  16. Glucose phosphorylation is not rate limiting for accumulation of glycogen from glucose in perfused livers from fasted rats

    International Nuclear Information System (INIS)

    Incorporation of Glc and Fru into glycogen was measured in perfused livers from 24-h fasted rats using [6-3H]Glc and [U-14C]Fru. For the initial 20 min, livers were perfused with low Glc (2 mM) to deplete hepatic glycogen and were perfused for the following 30 min with various combinations of Glc and Fru. With constant Fru (2 mM), increasing perfusate Glc increased the relative contribution of Glc carbons to glycogen (7.2 +/- 0.4, 34.9 +/- 2.8, and 59.1 +/- 2.7% at 2, 10, and 20 mM Glc, respectively; n = 5 for each). During perfusion with substrate levels seen during refeeding (10 mM Glc, 1.8 mumol/g/min gluconeogenic flux from 2 mM Fru), Fru provided 54.7 +/- 2.7% of the carbons for glycogen, while Glc provided only 34.9 +/- 2.8%, consistent with in vivo estimations. However, the estimated rate of Glc phosphorylation was at least 1.10 +/- 0.11 mumol/g/min, which exceeded by at least 4-fold the glycogen accumulation rate (0.28 +/- 0.04 mumol of glucose/g/min). The total rate of glucose 6-phosphate supply via Glc phosphorylation and gluconeogenesis (2.9 mumol/g/min) exceeded reported in vivo rates of glycogen accumulation during refeeding. Thus, in perfused livers of 24-h fasted rats there is an apparent redundancy in glucose 6-phosphate supply. These results suggest that the rate-limiting step for hepatic glycogen accumulation during refeeding is located between glucose 6-phosphate and glycogen, rather than at the step of Glc phosphorylation or in the gluconeogenic pathway

  17. Production of polyhydroxyalkanoates from fermented sugar cane molasses by a mixed culture enriched in glycogen accumulating organisms.

    Science.gov (United States)

    Bengtsson, Simon; Pisco, Ana R; Reis, Maria A M; Lemos, Paulo C

    2010-02-01

    Batch production of polyhydroxyalkanoates (PHAs) under aerobic conditions by an open mixed culture enriched in glycogen accumulating organisms (GAOs) with fermented sugar cane molasses as substrate was studied. The produced polymers contained five types of monomers, namely 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 3-hydroxy-2-methylbutyrate (3H2MB), 3-hydroxy-2-methylvalerate (3H2MV) and the medium chain length monomer 3-hydroxyhexanoate (3HHx). With fermented molasses as substrate, PHA was produced under concurrent consumption of stored glycogen with yields of 0.47-0.66 C-mol PHA per C-mol of total carbon substrate and with rates up to 0.65 C-mol/C-molX h. In order to investigate the role of glycogen during aerobic PHA accumulation in GAOs, synthetic single volatile fatty acids (VFAs) were used as substrates and it was found that the fate of glycogen was dependent on the type of VFA being consumed. Aerobic PHA accumulation occurred under concurrent glycogen consumption with acetate as substrate and under minor concurrent glycogen production with propionate as substrate. With butyrate and valerate as substrates, PHA accumulation occurred with the glycogen pool unaffected. The composition of the PHA was dependent on the VFA composition of the fermented molasses and was 56-70 mol-% 3HB, 13-43 mol-% 3HV, 1-23 mol-% 3HHx and 0-2 mol-% 3H2MB and 3H2MV. The high polymer yields and production rates suggest that enrichment of GAOs can be a fruitful strategy for mixed culture production of PHA from waste substrates. PMID:19958801

  18. Soft texture of atlantic salmon fillets is associated with glycogen accumulation.

    Directory of Open Access Journals (Sweden)

    Jacob S Torgersen

    Full Text Available Atlantic salmon (Salmo salar L. with soft fillets are not suited for manufacturing high quality products. Therefore fillets with insufficient firmness are downgraded, leading to severe economic losses to the farming and processing industries. In the current study, morphological characteristics of salmon fillets ranging from soft to hard were analysed. Different microscopic techniques were applied, including novel methods in this field of research: morphometric image analysis, periodic acid Schiff staining, immunofluorescence microscopy, transmission electron microscopy and fourier transform infrared microscopy. The results showed that the myocytes of soft muscle had detached cells with mitochondrial dysfunctions, large glycogen aggregates and enlarged inter cellular areas, void of extracellular matrix proteins, including lower amounts of sulfated glycoproteins. Myofibre-myofibre detachment and disappearance of the endomysium in soft muscles coincided with deterioration of important connective tissue constituents such as Collagen type I (Col I, Perlecan and Aggrecan. In summary our investigations show for the first time an association between soft flesh of Atlantic salmon and massive intracellular glycogen accumulation coinciding with degenerated mitochondria, myocyte detachment and altered extracellular matrix protein distribution. The results are important for further understanding the etiology of soft salmon.

  19. Polyphosphate- and glycogen-accumulating organisms in one EBPR system for liquid dairy manure.

    Science.gov (United States)

    Liu, Ze-Hua; Pruden, Amy; Ogejo, Jactone Arogo; Knowlton, Katharine F

    2014-07-01

    Two enhanced biological phosphorus removal (EBPR) sequencing batch reactors (SBR1, SBR2) treating liquid dairy manure were operated with the same hydraulic retention time (HRT) and solids retention time (SRT), but with different aeration cycles. During eight months of operation, both SBRs achieved good removal of total phosphorus (P) (TP; 56.8 and 73.5% for SBR1 and SBR2 respectively) and of orthophosphate (OP; 76.2 vs. 82.7%, P < 0.05). Growth dynamics of presumptive phosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) were examined by quantitative polymerase chain reaction (qPCR). SBR1 was enriched with a greater abundance of PAOs while SBR2 was characterized by a greater abundance of GAOs. These results demonstrate the capability of EBPR of dairy manure and challenge conventional wisdom, since greater abundance of PAOs in EBPR system was not associated with improved OP removal and greater abundance of GAOs did not indicate deterioration of the EBPR system. PMID:25112034

  20. Elucidating further phylogenetic diversity among the Defluviicoccus-related glycogen-accumulating organisms in activated sludge.

    Science.gov (United States)

    McIlroy, Simon; Seviour, Robert J

    2009-12-01

    Glycogen-accumulating organisms (GAO) are thought to out-compete the polyphosphate-accumulating organisms (PAO) in activated sludge communities removing phosphate (P). Two GAO groups are currently recognized, the gammaproteobacterial Candidatus'Competibacter phosphatis', and the alphaproteobacterial Defluviicoccus vanus-related tetrad forming organisms (TFOs). Both are phylogenetically diverse based on their 16S rRNA sequences, with the latter currently considered to contain members falling into three distinct clusters. This paper identifies members of an additional fourth Defluviicoccus cluster from 16S rRNA gene clone library data obtained from a laboratory-scale activated sludge plant community removing P, and details FISH probes designed against them. Probe DF181A was designed to target a single sequence and DF181B designed against the remaining sequences in the cluster. Cells hybridizing with these probes in the biomass samples tested always appeared as either TFOs or in large clusters of small cocci. Members of the Defluviicoccus-related organisms were commonly found in full-scale wastewater treatments plants, sometimes as a dominant population. PMID:23765935

  1. Cecropia peltata accumulates starch or soluble glycogen by differentially regulating starch biosynthetic genes

    OpenAIRE

    Bischof, Sylvain; Umhang, Martin; Eicke, Simona; Streb, Sebastian; Qi, Weihong; Zeeman, Samuel C.

    2013-01-01

    The branched glucans glycogen and starch are the most widespread storage carbohydrates in living organisms. The production of semicrystalline starch granules in plants is more complex than that of small, soluble glycogen particles in microbes and animals. However, the factors determining whether glycogen or starch is formed are not fully understood. The tropical tree Cecropia peltata is a rare example of an organism able to make either polymer type. Electron micrographs and quantitative measu...

  2. Glycogen accumulation in normal and irradiated minced muscle autografts on frog gastrocnemius

    International Nuclear Information System (INIS)

    Alterations induced in glycogen content and phosphorylase activity have been studied in normal and irradiated minced muscle autografts on frog gastrocnemius at days 1, 3, 5, 7, 10, 15 and 30 postgrafting. The changes observed in the glycogen content and phosphorylase activity conform to the degeneration and regeneration phases of muscle repair. An attempt has been made to explain the altered glycogen utilizing capacities of the frog skeletal muscle during its repair and regeneration. (author)

  3. Community structure evolution and enrichment of glycogen-accumulating organisms producing polyhydroxyalkanoates from fermented molasses.

    Science.gov (United States)

    Pisco, Ana R; Bengtsson, Simon; Werker, Alan; Reis, Maria A M; Lemos, Paulo C

    2009-07-01

    An open mixed culture was enriched with glycogen-accumulating organisms (GAOs) by using a sequencing batch reactor and treating an agroindustrial waste (sugar cane molasses) under cyclic anaerobic-aerobic conditions. Over a 1-year operating period, the culture exhibited a very stable GAO phenotype with an average polyhydroxyalkanoate (PHA) content of 17% total suspended solids. However, the GAO microbial community evolved over the course of operation to a culture exhibiting unusual characteristics in producing PHAs comprised of short-chain-length monomers, namely, 3-hydroxybutyrate, 3-hydroxy-2-methylbutyrate, 3-hydroxyvalerate, and 3-hydroxy-2-methylvalerate, and also, up to 31 mol% of the medium-chain-length (MCL) monomer 3-hydroxyhexanoate (3HHx). Microbial community analysis by fluorescence in situ hybridization revealed a concurrent long-term drift in the GAO community balance, from mainly "Candidatus Competibacter phosphatis" to mainly Defluviicoccus vanus-related organisms. The production of 3HHx was confirmed by (13)C nuclear magnetic resonance (NMR) and appeared to be related to the increased presence of D. vanus-related GAOs. These results suggest a broadened spectrum of material, chemical, and mechanical properties that can be achieved for biopolymers produced by open mixed cultures from fermented waste. The increased spectrum of polymer properties brings a wider scope of potential applications. PMID:19465533

  4. Molecular mechanism by which AMP-activated protein kinase activation promotes glycogen accumulation in muscle

    DEFF Research Database (Denmark)

    Hunter, Roger W; Treebak, Jonas Thue; Wojtaszewski, Jørgen;

    2011-01-01

    OBJECTIVE During energy stress, AMP-activated protein kinase (AMPK) promotes glucose transport and glycolysis for ATP production, while it is thought to inhibit anabolic glycogen synthesis by suppressing the activity of glycogen synthase (GS) to maintain the energy balance in muscle. Paradoxically...... transgenic mice overexpressing a kinase dead (KD) AMPK were incubated with glucose tracers and the AMPK-activating compound 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR) ex vivo. GS activity and glucose uptake and utilization (glycolysis and glycogen synthesis) were assessed. RESULTS Even though...

  5. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    OpenAIRE

    Zhang Bin; Xue Bin; Qiu Zhigang; Chen Zhiqiang; Li Junwen; Gong Taishi; Zou Wenci; Wang Jingfeng

    2015-01-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all ...

  6. Accumulibacter clades Type I and II performing kinetically different glycogen-accumulating organisms metabolisms for anaerobic substrate uptake.

    Science.gov (United States)

    Welles, L; Tian, W D; Saad, S; Abbas, B; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-10-15

    The anaerobic acetate (HAc) uptake stoichiometry of phosphorus-accumulating organisms (PAO) in enhanced biological phosphorus removal (EBPR) systems has been an extensive subject of study due to the highly variable reported stoichiometric values (e.g. anaerobic P-release/HAc-uptake ratios ranging from 0.01 up to 0.93 P-mol/C-mol). Often, such differences have been explained by the different applied operating conditions (e.g. pH) or occurrence of glycogen-accumulating organisms (GAO). The present study investigated the ability of biomass highly enriched with specific PAO clades ('Candidatus Accumulibacter phosphatis' Clade I and II, hereafter PAO I and PAO II) to adopt a GAO metabolism. Based on long-term experiments, when Poly-P is not stoichiometrically limiting for the anaerobic VFA uptake, PAO I performed the typical PAO metabolism (with a P/HAc ratio of 0.64 P-mol/C-mol); whereas PAO II performed a mixed PAO-GAO metabolism (showing a P/HAc ratio of 0.22 P-mol/C-mol). In short-term batch tests, both PAO I and II gradually shifted their metabolism to a GAO metabolism when the Poly-P content decreased, but the HAc-uptake rate of PAO I was 4 times lower than that of PAO II, indicating that PAO II has a strong competitive advantage over PAO I when Poly-P is stoichiometrically limiting the VFA uptake. Thus, metabolic flexibility of PAO clades as well as their intrinsic differences are additional factors leading to the controversial anaerobic stoichiometry and kinetic rates observed in previous studies. From a practical perspective, the dominant type of PAO prevailing in full-scale EBPR systems may affect the P-release processes for biological or combined biological and chemical P-removal and recovery and consequently the process performance. PMID:26189167

  7. Triacylglycerol Accumulation is not primarily affected in Myotubes established from Type 2 Diabetic Subjects

    DEFF Research Database (Denmark)

    Gaster, Michael; Beck-Nielsen, Henning

    2006-01-01

    In the present study, we investigated triacylglycerol (TAG) accumulation, glucose and fatty acid (FA) uptake, and glycogen synthesis (GS) in human myotubes from healthy, lean, and obese subjects with and without type 2 diabetes (T2D), exposed to increasing palmitate (PA) and oleate (OA) concentra......In the present study, we investigated triacylglycerol (TAG) accumulation, glucose and fatty acid (FA) uptake, and glycogen synthesis (GS) in human myotubes from healthy, lean, and obese subjects with and without type 2 diabetes (T2D), exposed to increasing palmitate (PA) and oleate (OA......-stimulated FA uptake (P<0.001), but did not correlate with insulin-stimulated glucose uptake for PA or OA (P>0.05). These results indicate that (1) TAG accumulation is not primarily affected in skeletal muscle tissue of obese and T2D; (2) induced inhibition of oxidative phosphorylation is followed by TAG...... skeletal muscle of obese and T2D subjects is adaptive....

  8. Glycogen metabolism in humans.

    Science.gov (United States)

    Adeva-Andany, María M; González-Lucán, Manuel; Donapetry-García, Cristóbal; Fernández-Fernández, Carlos; Ameneiros-Rodríguez, Eva

    2016-06-01

    In the human body, glycogen is a branched polymer of glucose stored mainly in the liver and the skeletal muscle that supplies glucose to the blood stream during fasting periods and to the muscle cells during muscle contraction. Glycogen has been identified in other tissues such as brain, heart, kidney, adipose tissue, and erythrocytes, but glycogen function in these tissues is mostly unknown. Glycogen synthesis requires a series of reactions that include glucose entrance into the cell through transporters, phosphorylation of glucose to glucose 6-phosphate, isomerization to glucose 1-phosphate, and formation of uridine 5'-diphosphate-glucose, which is the direct glucose donor for glycogen synthesis. Glycogenin catalyzes the formation of a short glucose polymer that is extended by the action of glycogen synthase. Glycogen branching enzyme introduces branch points in the glycogen particle at even intervals. Laforin and malin are proteins involved in glycogen assembly but their specific function remains elusive in humans. Glycogen is accumulated in the liver primarily during the postprandial period and in the skeletal muscle predominantly after exercise. In the cytosol, glycogen breakdown or glycogenolysis is carried out by two enzymes, glycogen phosphorylase which releases glucose 1-phosphate from the linear chains of glycogen, and glycogen debranching enzyme which untangles the branch points. In the lysosomes, glycogen degradation is catalyzed by α-glucosidase. The glucose 6-phosphatase system catalyzes the dephosphorylation of glucose 6-phosphate to glucose, a necessary step for free glucose to leave the cell. Mutations in the genes encoding the enzymes involved in glycogen metabolism cause glycogen storage diseases. PMID:27051594

  9. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Science.gov (United States)

    Bin, Zhang; Bin, Xue; Zhigang, Qiu; Zhiqiang, Chen; Junwen, Li; Taishi, Gong; Wenci, Zou; Jingfeng, Wang

    2015-08-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all NO3--N could be removed or reduced, some amount of NO2--N were accumulated in the reactor, and N2 was the main gaseous product. SEM analysis suggested that the granules were tightly packed with a large amount of tetrad-forming organisms (TFOs); filamentous bacteria served as the supporting structures for the granules. The microbial community structure of GAO granules was differed substantially from the inoculant conventional activated sludge. Most of the bacteria in the seed sludge grouped with members of Proteobacterium. FISH analysis confirmed that GAOs were the predominant members in the granules and were distributed evenly throughout the granular space. In contrast, PAOs were severely inhibited. Overall, cultivation of the GAO granules and utilizing their denitrifying capability can provide us with a new approach of nitrogen removal and saving more energy.

  10. Inactivation of the phosphoglucomutase gene pgm in Corynebacterium glutamicum affects cell shape and glycogen metabolism

    OpenAIRE

    2013-01-01

    In Corynebacterium glutamicum formation of glc-1-P (α-glucose-1-phosphate) from glc-6-P (glucose-6-phosphate) by α-Pgm (phosphoglucomutase) is supposed to be crucial for synthesis of glycogen and the cell wall precursors trehalose and rhamnose. Furthermore, Pgm is probably necessary for glycogen degradation and maltose utilization as glucan phosphorylases of both pathways form glc-1-P. We here show that C. glutamicum possesses at least two Pgm isoenzymes, the cg2800 (pgm) encoded enzyme contr...

  11. "Candidatus Propionivibrio aalborgensis": A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants.

    Science.gov (United States)

    Albertsen, Mads; McIlroy, Simon J; Stokholm-Bjerregaard, Mikkel; Karst, Søren M; Nielsen, Per H

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial "Candidatus Accumulibacter phosphatis" (Accumulibacter) and the model GAO being the gammaproteobacterial "Candidatus Competibacter phosphatis". Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set. PMID:27458436

  12. “Candidatus Propionivibrio aalborgensis”: A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Science.gov (United States)

    Albertsen, Mads; McIlroy, Simon J.; Stokholm-Bjerregaard, Mikkel; Karst, Søren M.; Nielsen, Per H.

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial “Candidatus Accumulibacter phosphatis” (Accumulibacter) and the model GAO being the gammaproteobacterial “Candidatus Competibacter phosphatis”. Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set. PMID:27458436

  13. Profiling of lipid and glycogen accumulations under different growth conditions in the sulfothermophilic red alga Galdieria sulphuraria.

    Science.gov (United States)

    Sakurai, Toshihiro; Aoki, Motohide; Ju, Xiaohui; Ueda, Tatsuya; Nakamura, Yasunori; Fujiwara, Shoko; Umemura, Tomonari; Tsuzuki, Mikio; Minoda, Ayumi

    2016-01-01

    The unicellular red alga Galdieria sulphuraria grows efficiently and produces a large amount of biomass in acidic conditions at high temperatures. It has great potential to produce biofuels and other beneficial compounds without becoming contaminated with other organisms. In G. sulphuraria, biomass measurements and glycogen and lipid analyses demonstrated that the amounts and compositions of glycogen and lipids differed when cells were grown under autotrophic, mixotrophic, and heterotrophic conditions. Maximum biomass production was obtained in the mixotrophic culture. High amounts of glycogen were obtained in the mixotrophic cultures, while the amounts of neutral lipids were similar between mixotrophic and heterotrophic cultures. The amounts of neutral lipids were highest in red algae, including thermophiles. Glycogen structure and fatty acids compositions largely depended on the growth conditions. PMID:26595665

  14. How Financial Literacy Affects Household Wealth Accumulation

    OpenAIRE

    Behrman, Jere R.; Mitchell, Olivia S.; Soo, Cindy K.; David Bravo

    2012-01-01

    This study isolates the causal effects of financial literacy and schooling on wealth accumulation using a new household dataset and an instrumental variables (IV) approach. Financial literacy and schooling attainment are both strongly positively associated with wealth outcomes in linear regression models, whereas the IV estimates reveal even more potent effects of financial literacy. They also indicate that the schooling effect only becomes positive when interacted with financial literacy. Es...

  15. Differential pattern of glycogen accumulation after protein phosphatase 1 glycogen-targeting subunit PPP1R6 overexpression, compared to PPP1R3C and PPP1R3A, in skeletal muscle cells

    Directory of Open Access Journals (Sweden)

    Montori-Grau Marta

    2011-11-01

    Full Text Available Abstract Background PPP1R6 is a protein phosphatase 1 glycogen-targeting subunit (PP1-GTS abundant in skeletal muscle with an undefined metabolic control role. Here PPP1R6 effects on myotube glycogen metabolism, particle size and subcellular distribution are examined and compared with PPP1R3C/PTG and PPP1R3A/GM. Results PPP1R6 overexpression activates glycogen synthase (GS, reduces its phosphorylation at Ser-641/0 and increases the extracted and cytochemically-stained glycogen content, less than PTG but more than GM. PPP1R6 does not change glycogen phosphorylase activity. All tested PP1-GTS-cells have more glycogen particles than controls as found by electron microscopy of myotube sections. Glycogen particle size is distributed for all cell-types in a continuous range, but PPP1R6 forms smaller particles (mean diameter 14.4 nm than PTG (36.9 nm and GM (28.3 nm or those in control cells (29.2 nm. Both PPP1R6- and GM-derived glycogen particles are in cytosol associated with cellular structures; PTG-derived glycogen is found in membrane- and organelle-devoid cytosolic glycogen-rich areas; and glycogen particles are dispersed in the cytosol in control cells. A tagged PPP1R6 protein at the C-terminus with EGFP shows a diffuse cytosol pattern in glucose-replete and -depleted cells and a punctuate pattern surrounding the nucleus in glucose-depleted cells, which colocates with RFP tagged with the Golgi targeting domain of β-1,4-galactosyltransferase, according to a computational prediction for PPP1R6 Golgi location. Conclusions PPP1R6 exerts a powerful glycogenic effect in cultured muscle cells, more than GM and less than PTG. PPP1R6 protein translocates from a Golgi to cytosolic location in response to glucose. The molecular size and subcellular location of myotube glycogen particles is determined by the PPP1R6, PTG and GM scaffolding.

  16. Experimental evaluation of decrease in the activities of polyphosphate/glycogen-accumulating organisms due to cell death and activity decay in activated sludge.

    Science.gov (United States)

    Hao, Xiaodi; Wang, Qilin; Cao, Yali; van Loosdrecht, Mark C M

    2010-06-15

    Decrease in bacterial activity (biomass decay) in activated sludge can result from cell death (reduction in the amount of active bacteria) and activity decay (reduction in the specific activity of active bacteria). The goal of this study was to experimentally differentiate between cell death and activity decay as the cause of decrease in bacterial activity. By means of measuring maximal anaerobic phosphate release rates, verifying membrane integrity by live/dead staining and verifying presence of 16S rRNA with fluorescence in situ hybridization (FISH), the decay rates and death rates of polyphosphate-accumulating organisms (PAOs) in a biological nutrient removal (BNR) system and a laboratory phosphate removing sequencing batch reactor (SBR) system were determined, respectively, under famine conditions. In addition, the decay rate and death rate of glycogen-accumulating organisms (GAOs) in a SBR system with an enrichment culture of GAOs were also measured under famine conditions. Hereto the maximal anaerobic volatile fatty acid uptake rates, live/dead staining, and FISH were used. The experiments revealed that in the BNR and enriched PAO-SBR systems, activity decay contributed 58% and 80% to the decreased activities of PAOs, and that cell death was responsible for 42% and 20% of decreases in their respective activities. In the enriched GAOs system, activity decay constituted a proportion of 74% of the decreased activity of GAOs, and cell death only accounted for 26% of the decrease of their activity. PMID:20178124

  17. “Candidatus Propionivibrio aalborgensis”: A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants

    DEFF Research Database (Denmark)

    Albertsen, Mads; McIlroy, Simon Jon; Stokholm-Bjerregaard, Mikkel;

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater...

  18. Brain glycogen

    DEFF Research Database (Denmark)

    Obel, Linea Lykke Frimodt; Müller, Margit S; Walls, Anne B;

    2012-01-01

    Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia....... In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies-it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic...... activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms...

  19. Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate.

    Science.gov (United States)

    Pronk, M; Abbas, B; Kleerebezem, R; van Loosdrecht, M C M

    2015-09-01

    The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens and prevented unwanted methane formation. In absence of methanogens, methanol was converted aerobically, while granule formation remained stable. At high SRT values (51 days), γ-Proteobacteria were responsible for acetate removal through anaerobic uptake and subsequent aerobic growth on storage polymers formed [so called metabolism of glycogen-accumulating organisms (GAO)]. When lowering the SRT (24 days), Defluviicoccus-related organisms (cluster II) belonging to the α-Proteobacteria outcompeted acetate consuming γ-Proteobacteria at 35°C. DNA from the Defluviicoccus-related organisms in cluster II was not extracted by the standard DNA extraction method but with liquid nitrogen, which showed to be more effective. Remarkably, the two GAO types of organisms grew separately in two clearly different types of granules. This work further highlights the potential of aerobic granular sludge systems to effectively influence the microbial communities through sludge age control in order to optimize the wastewater treatment processes. PMID:26059251

  20. Sodium-Glucose Cotransporter 2 Inhibitor and a Low Carbohydrate Diet Affect Gluconeogenesis and Glycogen Content Differently in the Kidney and the Liver of Non-Diabetic Mice.

    Directory of Open Access Journals (Sweden)

    Kuralay Atageldiyeva

    Full Text Available A low carbohydrate diet (LCHD as well as sodium glucose cotransporter 2 inhibitors (SGLT2i may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCHD and treated with/without the SGLT-2 inhibitor, ipragliflozin. We compared metabolic parameters, gene expression for transcripts related to glucose and fat metabolism, and glycogen content in the kidney and the liver among the groups. SGLT2i but not LCHD improved glucose excursion after an oral glucose load compared to NCHD, although all groups presented comparable non-fasted glycemia. Both the LCHD and SGLT2i treatments increased calorie-intake, whereas only the LCHD increased body weight compared to the NCHD, epididimal fat mass and developed insulin resistance. Gene expression of certain gluconeogenic enzymes was simultaneously upregulated in the kidney of SGLT2i treated group, as well as in the liver of the LCHD treated group. The SGLT2i treated groups showed markedly lower glycogen content in the liver, but induced glycogen accumulation in the kidney. We conclude that LCHD induces deleterious metabolic changes in the non-diabetic mice. Our results suggest that SGLT2i induced gluconeogenesis mainly in the kidney, whereas for LCHD it was predominantly in the liver.

  1. Sodium-Glucose Cotransporter 2 Inhibitor and a Low Carbohydrate Diet Affect Gluconeogenesis and Glycogen Content Differently in the Kidney and the Liver of Non-Diabetic Mice.

    Science.gov (United States)

    Atageldiyeva, Kuralay; Fujita, Yukihiro; Yanagimachi, Tsuyoshi; Mizumoto, Katsutoshi; Takeda, Yasutaka; Honjo, Jun; Takiyama, Yumi; Abiko, Atsuko; Makino, Yuichi; Haneda, Masakazu

    2016-01-01

    A low carbohydrate diet (LCHD) as well as sodium glucose cotransporter 2 inhibitors (SGLT2i) may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCHD) and treated with/without the SGLT-2 inhibitor, ipragliflozin. We compared metabolic parameters, gene expression for transcripts related to glucose and fat metabolism, and glycogen content in the kidney and the liver among the groups. SGLT2i but not LCHD improved glucose excursion after an oral glucose load compared to NCHD, although all groups presented comparable non-fasted glycemia. Both the LCHD and SGLT2i treatments increased calorie-intake, whereas only the LCHD increased body weight compared to the NCHD, epididimal fat mass and developed insulin resistance. Gene expression of certain gluconeogenic enzymes was simultaneously upregulated in the kidney of SGLT2i treated group, as well as in the liver of the LCHD treated group. The SGLT2i treated groups showed markedly lower glycogen content in the liver, but induced glycogen accumulation in the kidney. We conclude that LCHD induces deleterious metabolic changes in the non-diabetic mice. Our results suggest that SGLT2i induced gluconeogenesis mainly in the kidney, whereas for LCHD it was predominantly in the liver. PMID:27327650

  2. Glycogenic Hepatopathy in Type 1 Diabetes Mellitus

    OpenAIRE

    Murat Atmaca; Rifki Ucler; Mehmet Kartal; Ismet Seven; Murat Alay; Irfan Bayram; Sehmus Olmez

    2015-01-01

    Glycogenic hepatopathy is a rare cause of high transaminase levels in type 1 diabetes mellitus. This condition, characterized by elevated liver enzymes and hepatomegaly, is caused by irreversible and excessive accumulation of glycogen in hepatocytes. This is a case report on a 19-year-old male case, diagnosed with glycogenic hepatopathy. After the diagnosis was documented by liver biopsy, the case was put on glycemic control which led to significant decline in hepatomegaly and liver enzymes. ...

  3. Campylobacter jejuni CsrA complements an Escherichia coli csrA mutation for the regulation of biofilm formation, motility and cellular morphology but not glycogen accumulation

    Directory of Open Access Journals (Sweden)

    Fields Joshua A

    2012-10-01

    Full Text Available Abstract Background Although Campylobacter jejuni is consistently ranked as one of the leading causes of bacterial diarrhea worldwide, the mechanisms by which C. jejuni causes disease and how they are regulated have yet to be clearly defined. The global regulator, CsrA, has been well characterized in several bacterial genera and is known to regulate a number of independent pathways via a post transcriptional mechanism, but remains relatively uncharacterized in the genus Campylobacter. Previously, we reported data illustrating the requirement for CsrA in several virulence related phenotypes of C. jejuni strain 81–176, indicating that the Csr pathway is important for Campylobacter pathogenesis. Results We compared the Escherichia coli and C. jejuni orthologs of CsrA and characterized the ability of the C. jejuni CsrA protein to functionally complement an E. coli csrA mutant. Phylogenetic comparison of E. coli CsrA to orthologs from several pathogenic bacteria demonstrated variability in C. jejuni CsrA relative to the known RNA binding domains of E. coli CsrA and in several amino acids reported to be involved in E. coli CsrA-mediated gene regulation. When expressed in an E. coli csrA mutant, C. jejuni CsrA succeeded in recovering defects in motility, biofilm formation, and cellular morphology; however, it failed to return excess glycogen accumulation to wild type levels. Conclusions These findings suggest that C. jejuni CsrA is capable of efficiently binding some E. coli CsrA binding sites, but not others, and provide insight into the biochemistry of C. jejuni CsrA.

  4. Identity of the Growth-Limiting Nutrient Strongly Affects Storage Carbohydrate Accumulation in Anaerobic Chemostat Cultures of Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Hazelwood, L.A.; Walsh, M.C.; Luttik, M.A.H.; Daran-Lapujade, P.; Pronk, J.T.; Daran, J.M.

    2009-01-01

    OA Fund TU Delft Accumulation of glycogen and trehalose in nutrient-limited cultures of Saccharomyces cerevisiae is negatively correlated with the specific growth rate. Additionally, glucose-excess conditions (i.e., growth limitation by nutrients other than glucose) are often implicated in high-lev

  5. No effect of glycogen level on glycogen metabolism during high intensity exercise

    DEFF Research Database (Denmark)

    Vandenberghe, Katleen; Hespel, P.; Eynde, Bart Vanden;

    1995-01-01

    , either for 1 min 45 s (protocol 1; N = 18) or to exhaustion (protocol 2; N = 14). The exercise tests were preceded by either 5 d on a controlled normal (N) diet, or by 2 d of glycogen-depleting exercise accompanied by the normal diet followed by 3 d on a carbohydrate-rich (CHR) diet. In protocol 1......This study examined the effect of glycogen supercompensation on glycogen breakdown, muscle and blood lactate accumulation, blood-pH, and performance during short-term high-intensity exercise. Young healthy volunteers performed two supramaximal (125% of VO2max) exercise tests on a bicycle ergometer...... blood-lactate, and the fall in blood-pH were similar during N and CHR. In protocol 2, time to exhaustion was identical for N and CHR. It is concluded that during short-term intense exercise during which muscle glycogen availability exceeds glycogen demand, rate of glycogen breakdown, lactate...

  6. No effect of glycogen level on glycogen metabolism during high intensity exercise.

    Science.gov (United States)

    Vandenberghe, K; Hespel, P; Vanden Eynde, B; Lysens, R; Richter, E A

    1995-09-01

    This study examined the effect of glycogen supercompensation on glycogen breakdown, muscle and blood lactate accumulation, blood-pH, and performance during short-term high-intensity exercise. Young healthy volunteers performed two supramaximal (125% of VO2max) exercise tests on a bicycle ergometer, either for 1 min 45 s (protocol 1; N = 18) or to exhaustion (protocol 2; N = 14). The exercise tests were preceded by either 5 d on a controlled normal (N) diet, or by 2 d of glycogen-depleting exercise accompanied by the normal diet followed by 3 d on a carbohydrate-rich (CHR) diet. In protocol 1, preexercise muscle glycogen concentrations were 364 +/- 23 and 568 +/- 35 mumol.g-1 d.w. in the N and CHR condition, respectively (P < 0.05). During the exertion, glycogen concentration in the M. quadriceps decreased to the same extent in both groups. Accordingly, the exercise-induced increases in muscle and blood-lactate, and the fall in blood-pH were similar during N and CHR. In protocol 2, time to exhaustion was identical for N and CHR. It is concluded that during short-term intense exercise during which muscle glycogen availability exceeds glycogen demand, rate of glycogen breakdown, lactate accumulation, and performance are regulated irrespective of the preexercise muscle glycogen level. PMID:8531626

  7. Patterns of glycogen turnover in liver characterized by computer modeling

    International Nuclear Information System (INIS)

    The authors used a computer model of liver glycogen turnover to reexamine the data of Devos and Hers, who reported the time course of accumulation in and loss from glycogen of label originating in [1-14C]galactose injected at different times after the start of refeeding of 40-h fasted mice or rats. In the present study computer representation of individual glycogen molecules was utilized to account for growth and degradation of glycogen according to specific hypothetical patterns. Using this model they could predict the accumulation and localization within glycogen of labeled glucose residues and compare the predictions with the previously published data. They considered three specific hypotheses of glycogen accumulation during refeeding: (1) simultaneous, (2) sequential, and (3) accelerating growth. Hypothetical patterns of glycogen degradation were (1) ordered and (2) random degradation. The pattern of glycogen synthesis consistent with experimental data was a steadily increasing number of growing glycogen molecules, whereas during degradation glycogen molecules are exposed to degrading enzymes randomly, rather than in a specific reverse order of synthesis. These patterns predict the existence of a specific mechanism for the steadily increasing seeding of new glycogen molecules during synthesis

  8. Glycogen: the forgotten cerebral energy store.

    Science.gov (United States)

    Gruetter, Rolf

    2003-10-15

    The brain contains a significant amount of glycogen that is an order of magnitude smaller than that in muscle, but several-fold higher than the cerebral glucose content. Although the precise role of brain glycogen to date is unknown, it seems affected by focal activation, neurotransmitters, and overall electrical activity and hormones. Based on its relatively low concentration, the role of brain glycogen as a significant energy store has been discounted. This work reviews recent experimental evidence that brain glycogen is an important reserve of glucose equivalents: (1) glial glycogen can provide the majority of the glucose supply deficit during hypoglycemia for more than 100 min, consistent with the proposal that glial lactate is a fuel for neurons; (2) glycogen concentrations may be as high as 10 micromol/g, substantially higher than was thought previously; (3) glucose cycling in and out of glycogen amounts to approximately 1% of the cerebral metabolic rate of glucose (CMRglc) in human and rat brain, amounting to an effective stability of glycogen in the resting awake brain during euglycemia and hyperglycemia, (4) brain glycogen metabolism/concentrations are insulin/glucose sensitive; and (5) after a single episode of hypoglycemia, brain glycogen levels rebound to levels that exceed the pre-hypoglycemic concentrations (supercompensation). This experimental evidence supports the proposal that brain glycogen may be involved in the development of diabetes complications, specifically impaired glucose sensing (hypoglycemia unawareness) observed clinically in some diabetes patients under insulin treatment. It is proposed further that brain glycogen becomes important in any metabolic state where supply transiently cannot meet demand, such conditions that could occur during prolonged focal activation, sleep deprivation, seizures, and mild hypoxia. PMID:14515346

  9. Starch Binding Domain-containing Protein 1 Plays a Dominant Role in Glycogen Transport to Lysosomes in Liver.

    Science.gov (United States)

    Sun, Tao; Yi, Haiqing; Yang, Chunyu; Kishnani, Priya S; Sun, Baodong

    2016-08-01

    A small portion of cellular glycogen is transported to and degraded in lysosomes by acid α-glucosidase (GAA) in mammals, but it is unclear why and how glycogen is transported to the lysosomes. Stbd1 has recently been proposed to participate in glycogen trafficking to lysosomes. However, our previous study demonstrated that knockdown of Stbd1 in GAA knock-out mice did not alter lysosomal glycogen storage in skeletal muscles. To further determine whether Stbd1 participates in glycogen transport to lysosomes, we generated GAA/Stbd1 double knock-out mice. In fasted double knock-out mice, glycogen accumulation in skeletal and cardiac muscles was not affected, but glycogen content in liver was reduced by nearly 73% at 3 months of age and by 60% at 13 months as compared with GAA knock-out mice, indicating that the transport of glycogen to lysosomes was suppressed in liver by the loss of Stbd1. Exogenous expression of human Stbd1 in double knock-out mice restored the liver lysosomal glycogen content to the level of GAA knock-out mice, as did a mutant lacking the Atg8 family interacting motif (AIM) and another mutant that contains only the N-terminal 24 hydrophobic segment and the C-terminal starch binding domain (CBM20) interlinked by an HA tag. Our results demonstrate that Stbd1 plays a dominant role in glycogen transport to lysosomes in liver and that the N-terminal transmembrane region and the C-terminal CBM20 domain are critical for this function. PMID:27358407

  10. Glycogenic Hepatopathy in Type 1 Diabetes Mellitus.

    Science.gov (United States)

    Atmaca, Murat; Ucler, Rifki; Kartal, Mehmet; Seven, Ismet; Alay, Murat; Bayram, Irfan; Olmez, Sehmus

    2015-01-01

    Glycogenic hepatopathy is a rare cause of high transaminase levels in type 1 diabetes mellitus. This condition, characterized by elevated liver enzymes and hepatomegaly, is caused by irreversible and excessive accumulation of glycogen in hepatocytes. This is a case report on a 19-year-old male case, diagnosed with glycogenic hepatopathy. After the diagnosis was documented by liver biopsy, the case was put on glycemic control which led to significant decline in hepatomegaly and liver enzymes. It was emphasized that, in type 1 diabetes mellitus cases, hepatopathy should also be considered in the differential diagnoses of elevated liver enzyme and hepatomegaly. PMID:26347835

  11. Glycogenic Hepatopathy in Type 1 Diabetes Mellitus

    Science.gov (United States)

    Atmaca, Murat; Ucler, Rifki; Kartal, Mehmet; Seven, Ismet; Alay, Murat; Bayram, Irfan; Olmez, Sehmus

    2015-01-01

    Glycogenic hepatopathy is a rare cause of high transaminase levels in type 1 diabetes mellitus. This condition, characterized by elevated liver enzymes and hepatomegaly, is caused by irreversible and excessive accumulation of glycogen in hepatocytes. This is a case report on a 19-year-old male case, diagnosed with glycogenic hepatopathy. After the diagnosis was documented by liver biopsy, the case was put on glycemic control which led to significant decline in hepatomegaly and liver enzymes. It was emphasized that, in type 1 diabetes mellitus cases, hepatopathy should also be considered in the differential diagnoses of elevated liver enzyme and hepatomegaly. PMID:26347835

  12. Insulin resistance after a 72-h fast is associated with impaired AS160 phosphorylation and accumulation of lipid and glycogen in human skeletal muscle

    DEFF Research Database (Denmark)

    Vendelbo, M; Clasen, B F F; Treebak, Jonas Thue;

    2012-01-01

    During fasting, human skeletal muscle depends on lipid oxidation for its energy substrate metabolism. This is associated with the development of insulin resistance and a subsequent reduction of insulin-stimulated glucose uptake. The underlying mechanisms controlling insulin action on skeletal...... muscle under these conditions are unresolved. In a randomized design, we investigated eight healthy subjects after a 72-h fast compared with a 10-h overnight fast. Insulin action on skeletal muscle was assessed by a hyperinsulinemic euglycemic clamp and by determining insulin signaling to glucose...... transport. In addition, substrate oxidation, skeletal muscle lipid content, regulation of glycogen synthesis, and AMPK signaling were assessed. Skeletal muscle insulin sensitivity was reduced profoundly in response to a 72-h fast and substrate oxidation shifted to predominantly lipid oxidation. This was...

  13. Characterization of a canine model of glycogen storage disease type IIIa

    Directory of Open Access Journals (Sweden)

    Haiqing Yi

    2012-11-01

    Glycogen storage disease type IIIa (GSD IIIa is an autosomal recessive disease caused by deficiency of glycogen debranching enzyme (GDE in liver and muscle. The disorder is clinically heterogeneous and progressive, and there is no effective treatment. Previously, a naturally occurring dog model for this condition was identified in curly-coated retrievers (CCR. The affected dogs carry a frame-shift mutation in the GDE gene and have no detectable GDE activity in liver and muscle. We characterized in detail the disease expression and progression in eight dogs from age 2 to 16 months. Monthly blood biochemistry revealed elevated and gradually increasing serum alanine transaminase (ALT, aspartate transaminase (AST and alkaline phosphatase (ALP activities; serum creatine phosphokinase (CPK activity exceeded normal range after 12 months. Analysis of tissue biopsy specimens at 4, 12 and 16 months revealed abnormally high glycogen contents in liver and muscle of all dogs. Fasting liver glycogen content increased from 4 months to 12 months, but dropped at 16 months possibly caused by extended fibrosis; muscle glycogen content continually increased with age. Light microscopy revealed significant glycogen accumulation in hepatocytes at all ages. Liver histology showed progressive, age-related fibrosis. In muscle, scattered cytoplasmic glycogen deposits were present in most cells at 4 months, but large, lake-like accumulation developed by 12 and 16 months. Disruption of the contractile apparatus and fraying of myofibrils was observed in muscle at 12 and 16 months by electron microscopy. In conclusion, the CCR dogs are an accurate model of GSD IIIa that will improve our understanding of the disease progression and allow opportunities to investigate treatment interventions.

  14. Characterization of a canine model of glycogen storage disease type IIIa.

    Science.gov (United States)

    Yi, Haiqing; Thurberg, Beth L; Curtis, Sarah; Austin, Stephanie; Fyfe, John; Koeberl, Dwight D; Kishnani, Priya S; Sun, Baodong

    2012-11-01

    Glycogen storage disease type IIIa (GSD IIIa) is an autosomal recessive disease caused by deficiency of glycogen debranching enzyme (GDE) in liver and muscle. The disorder is clinically heterogeneous and progressive, and there is no effective treatment. Previously, a naturally occurring dog model for this condition was identified in curly-coated retrievers (CCR). The affected dogs carry a frame-shift mutation in the GDE gene and have no detectable GDE activity in liver and muscle. We characterized in detail the disease expression and progression in eight dogs from age 2 to 16 months. Monthly blood biochemistry revealed elevated and gradually increasing serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) activities; serum creatine phosphokinase (CPK) activity exceeded normal range after 12 months. Analysis of tissue biopsy specimens at 4, 12 and 16 months revealed abnormally high glycogen contents in liver and muscle of all dogs. Fasting liver glycogen content increased from 4 months to 12 months, but dropped at 16 months possibly caused by extended fibrosis; muscle glycogen content continually increased with age. Light microscopy revealed significant glycogen accumulation in hepatocytes at all ages. Liver histology showed progressive, age-related fibrosis. In muscle, scattered cytoplasmic glycogen deposits were present in most cells at 4 months, but large, lake-like accumulation developed by 12 and 16 months. Disruption of the contractile apparatus and fraying of myofibrils was observed in muscle at 12 and 16 months by electron microscopy. In conclusion, the CCR dogs are an accurate model of GSD IIIa that will improve our understanding of the disease progression and allow opportunities to investigate treatment interventions. PMID:22736456

  15. Glycogen storage diseases: New perspectives

    Institute of Scientific and Technical Information of China (English)

    Hasan (O)zen

    2007-01-01

    Glycogen storage diseases (GSD) are inherited metabolic disorders of glycogen metabolism. Different hormones,including insulin, glucagon, and cortisol regulate the relationship of glycolysis, gluconeogenesis and glycogen synthesis. The overall GSD incidence is estimated 1 case per 20 000-43 000 live births. There are over 12 types and they are classified based on the enzyme deficiency and the affected tissue. Disorders of glycogen degradation may affect primarily the liver, the muscle,or both. Type Ⅰ a involves the liver, kidney and intestine (and Ⅰ b also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, hypoglycemia,hyperlactatemia, hyperuricemia and hyperlipidemia. Type Ⅲa involves both the liver and muscle, and Ⅲb solely the liver. The liver symptoms generally improve with age.Type Ⅳ usually presents in the first year of life, with hepatomegaly and growth retardation. The disease in general is progressive to cirrhosis. Type Ⅵ and Ⅸ are a heterogeneous group of diseases caused by a deficiency of the liver phosphorylase and phosphorylase kinase system. There is no hyperuricemia or hyperlactatemia.Type Ⅺ is characterized by hepatic glycogenosis and renal Fanconi syndrome. Type Ⅱ is a prototype of inborn lysosomal storage diseases and involves many organs but primarily the muscle. Types Ⅴ and Ⅶ involve only the muscle.

  16. PGC-1α induces mitochondrial and myokine transcriptional programs and lipid droplet and glycogen accumulation in cultured human skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Emma Mormeneo

    Full Text Available The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α is a chief activator of mitochondrial and metabolic programs and protects against atrophy in skeletal muscle (skm. Here we tested whether PGC-1α overexpression could restructure the transcriptome and metabolism of primary cultured human skm cells, which display a phenotype that resembles the atrophic phenotype. An oligonucleotide microarray analysis was used to reveal the effects of PGC-1α on the whole transcriptome. Fifty-three different genes showed altered expression in response to PGC-1α: 42 upregulated and 11 downregulated. The main gene ontologies (GO associated with the upregulated genes were mitochondrial components and processes and this was linked with an increase in COX activity, an indicator of mitochondrial content. Furthermore, PGC-1α enhanced mitochondrial oxidation of palmitate and lactate to CO(2, but not glucose oxidation. The other most significantly associated GOs for the upregulated genes were chemotaxis and cytokine activity, and several cytokines, including IL-8/CXCL8, CXCL6, CCL5 and CCL8, were within the most highly induced genes. Indeed, PGC-1α highly increased IL-8 cell protein content. The most upregulated gene was PVALB, which is related to calcium signaling. Potential metabolic regulators of fatty acid and glucose storage were among mainly regulated genes. The mRNA and protein level of FITM1/FIT1, which enhances the formation of lipid droplets, was raised by PGC-1α, while in oleate-incubated cells PGC-1α increased the number of smaller lipid droplets and modestly triglyceride levels, compared to controls. CALM1, the calcium-modulated δ subunit of phosphorylase kinase, was downregulated by PGC-1α, while glycogen phosphorylase was inactivated and glycogen storage was increased by PGC-1α. In conclusion, of the metabolic transcriptome deficiencies of cultured skm cells, PGC-1α rescued the expression

  17. Exercise in muscle glycogen storage diseases

    DEFF Research Database (Denmark)

    Preisler, Nicolai Rasmus; Haller, Ronald G; Vissing, John

    2015-01-01

    Glycogen storage diseases (GSD) are inborn errors of glycogen or glucose metabolism. In the GSDs that affect muscle, the consequence of a block in skeletal muscle glycogen breakdown or glucose use, is an impairment of muscular performance and exercise intolerance, owing to 1) an increase in glyco...... have examined the effect of regular exercise training in different types of GSD. Finally, we consider how oral substrate supplementation can improve exercise tolerance and we discuss the precautions that apply to persons with GSD that engage in exercise....

  18. Monoclonal antibodies against accumulation-associated protein affect EPS biosynthesis and enhance bacterial accumulation of Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Jian Hu

    Full Text Available Because there is no effective antibiotic to eradicate Staphylococcus epidermidis biofilm infections that lead to the failure of medical device implantations, the development of anti-biofilm vaccines is necessary. Biofilm formation by S. epidermidis requires accumulation-associated protein (Aap that contains sequence repeats known as G5 domains, which are responsible for the Zn(2+-dependent dimerization of Aap to mediate intercellular adhesion. Antibodies against Aap have been reported to inhibit biofilm accumulation. In the present study, three monoclonal antibodies (MAbs against the Aap C-terminal single B-repeat construct followed by the 79-aa half repeat (AapBrpt1.5 were generated. MAb(18B6 inhibited biofilm formation by S. epidermidis RP62A to 60% of the maximum, while MAb(25C11 and MAb(20B9 enhanced biofilm accumulation. All three MAbs aggregated the planktonic bacteria to form visible cell clusters. Epitope mapping revealed that the epitope of MAb(18B6, which recognizes an identical area within AapBrpt constructs from S. epidermidis RP62A, was not shared by MAb(25C11 and MAb(20B9. Furthermore, all three MAbs were found to affect both Aap expression and extracellular polymeric substance (EPS, including extracellular DNA and PIA biosynthesis in S. epidermidis and enhance the cell accumulation. These findings contribute to a better understanding of staphylococcal biofilm formation and will help to develop epitope-peptide vaccines against staphylococcal infections.

  19. GLYCOGEN IN BACILLUS-SUBTILIS - MOLECULAR CHARACTERIZATION OF AN OPERON ENCODING ENZYMES INVOLVED IN GLYCOGEN BIOSYNTHESIS AND DEGRADATION

    NARCIS (Netherlands)

    KIEL, JAKW; BOELS, JM; BELDMAN, G; VENEMA, G

    1994-01-01

    Although it has never been reported that Bacillus subtilis is capable of accumulating glycogen, we have isolated a region from the chromosome of B. subtilis containing a glycogen operon. The operon is located directly downstream from trnB, which maps at 275 degrees on the B. subtilis chromosome. It

  20. A functional glycogen biosynthesis pathway in Lactobacillus acidophilus: expression and analysis of the glg operon.

    Science.gov (United States)

    Goh, Yong Jun; Klaenhammer, Todd R

    2013-09-01

    Glycogen metabolism contributes to energy storage and various physiological functions in some prokaryotes, including colonization persistence. A role for glycogen metabolism is proposed on the survival and fitness of Lactobacillus acidophilus, a probiotic microbe, in the human gastrointestinal environment. L. acidophilus NCFM possesses a glycogen metabolism (glg) operon consisting of glgBCDAP-amy-pgm genes. Expression of the glg operon and glycogen accumulation were carbon source- and growth phase-dependent, and were repressed by glucose. The highest intracellular glycogen content was observed in early log-phase cells grown on trehalose, which was followed by a drastic decrease of glycogen content prior to entering stationary phase. In raffinose-grown cells, however, glycogen accumulation gradually declined following early log phase and was maintained at stable levels throughout stationary phase. Raffinose also induced an overall higher temporal glg expression throughout growth compared with trehalose. Isogenic ΔglgA (glycogen synthase) and ΔglgB (glycogen-branching enzyme) mutants are glycogen-deficient and exhibited growth defects on raffinose. The latter observation suggests a reciprocal relationship between glycogen synthesis and raffinose metabolism. Deletion of glgB or glgP (glycogen phosphorylase) resulted in defective growth and increased bile sensitivity. The data indicate that glycogen metabolism is involved in growth maintenance, bile tolerance and complex carbohydrate utilization in L. acidophilus. PMID:23879596

  1. Accumulation of heavy metals in sunflower and sorghum plants affected by the Guadiamar spill.

    Science.gov (United States)

    Murillo, J M; Marañón, T; Cabrera, F; López, R

    1999-12-01

    The collapse of a pyrite-mining, tailing dam on 25 April 1998 contaminated approximately 2000 ha of croplands along the Agrio and Guadiamar river valleys in southern Spain. This paper reports the accumulation of chemical elements in soil and in two crops--sunflower and sorghum--affected by the spill. Total concentrations of As, Bi, Cd, Cu, Mn, Pb, Sb, Tl and Zn in spill-affected soils were greater than in adjacent, unaffected soils. Leaves of spill-affected crop plants had higher nutrient (K, Ca and Mg for sunflower and N and K for sorghum) concentrations than controls, indicating a 'fertilising' effect caused by the sludge. Seeds of spill-affected sunflower plants did accumulate more As, Cd, Cu and Zn than controls, but values were below toxic levels. Leaves of sorghum plants accumulated more As, Bi, Cd, Mn, Pb, Tl and Zn than controls, but these values were also below toxic levels for livestock consumption. In general, none of the heavy metals studied in both crops reached either phytotoxic or toxic levels for humans or livestock. Nevertheless, a continuous monitoring of heavy metal accumulation in soil and plants must be established in the spill-affected area. PMID:10635586

  2. Azithromycin inhibits neutrophil accumulation in airways by affecting interleukin- 17 downstream signals

    Institute of Scientific and Technical Information of China (English)

    Nguyen Van Luu; YANG Jiong; QU Xue-ju; GUO Ming; WANG Xin; XIAN Qiao-yang; TANG Zhi-jiao; HUANG Zhi-xiang; WANG Yong

    2012-01-01

    Background Azithromycin can reduce neutrophil accumulation in neutrophilic pulmonary diseases.However,the precise mechanism behind this action remains unknown.Our experiment assessed whether azithromycin inhibits neutrophil accumulation in the airways by affecting interleukin-17 (IL-17) downstream signals.Methods Mice were pretreated with azithromycin before murine IL-17A (mlL-17) stimulation.After the mlL-17 stimulation,the levels of six neutrophil-mobilizing cytokines were determined by enzyme-linked immunosorbent assay (ELISA) tests in bronchoalveolar lavage (BAL) fluid; IL-6,CXC chemokine ligand-1 (CXCL-1),CXCL-5,macrophage inflammatory protein-2 (MIP-2),granulocyte colony-stimulating factor (G-CSF),and granulocyte macrophage colony-stimulating factor (GM-CSF).The number of neutrophils in BAL fluid were evaluated by cytospin preparations.Results (1) Azithromycin pretreatment significantly inhibited both the release of three neutrophil-mobilizing cytokines (MIP-2,CXCL-5 and GM-CSF) and the accumulation of neutrophils in airways caused by mlL-17 stimulation.(2) The levels of three neutrophil-mobilizing cytokines (IL-6,MIP-2 and GM-CSF) were positively correlated with the numbers of neutrophil in BAL fluid.Conclusions Azithromycin can inhibit neutrophil accumulation in the airways by affecting IL-17 downstream signals.This finding suggests that macrolide antibiotic application might be useful in prevention of neutrophilic pulmonary diseases characterized by high levels of IL-17.

  3. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    Science.gov (United States)

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas. PMID:26974480

  4. The role of skeletal muscle glycogen breakdown for regulation of insulin sensitivity by exercise

    Directory of Open Access Journals (Sweden)

    Jørgen eJensen

    2011-12-01

    Full Text Available Glycogen is the storage form of carbohydrates in mammals. In humans the majority of glycogen is stored in skeletal muscles (~500 g and the liver (~100 g. Food is supplied in larger meals, but the blood glucose concentration has to be kept within narrow limits to survive and stay healthy. Therefore, the body has to cope with periods of excess carbohydrates and periods without supplementation. Healthy persons remove blood glucose rapidly when glucose is in excess, but insulin-stimulated glucose disposal is reduced in insulin resistant and type 2 diabetic subjects. During a hyperinsulinemic euglycaemic clamp, 70-90 % of glucose disposal will be stored as muscle glycogen in healthy subjects. The glycogen stores in skeletal muscles are limited because an efficient feedback-mediated inhibition of glycogen synthase prevents accumulation. De novo lipid synthesis can contribute to glucose disposal when glycogen stores are filled. Exercise physiologists normally consider glycogen’s main function as energy substrate. Glycogen is the main energy substrate during exercise intensity above 70 % of maximal oxygen uptake (VO2max and fatigue develops when the glycogen stores are depleted in the active muscles. After exercise, the rate of glycogen synthesis is increased to replete glycogen stores, and blood glucose is the substrate. Indeed insulin-stimulated glucose uptake and glycogen synthesis is elevated after exercise, which, from an evolutional point of view, will favour glycogen repletion and preparation for new fight or flight events. In the modern society, the reduced glycogen stores in skeletal muscles after exercise allows carbohydrates to be stored as muscle glycogen and prevents that glucose is channelled to de novo lipid synthesis, which over time will causes ectopic fat accumulation and insulin resistance. The reduction of skeletal muscle glycogen after exercise allows a healthy storage of carbohydrates after meals and prevents development of type

  5. Lycopene Accumulation Affects the Biosynthesis of Some Carotenoid-related Volatiles Independent of Ethylene in Tomato

    Institute of Scientific and Technical Information of China (English)

    Hongyan Gao; Hongliang Zhu; Yi Shao; Anjun Chen; Chengwen Lu; Benzhong Zhu; Yunbo Luo

    2008-01-01

    For elucidating the regulatory mechanism of ethylene on carotenoid-related volatiles (open chain) compounds and the relationship between lycopene and carotenoid-related volatiles,transgenic tomato fruits in which ACC synthase was suppressed were used.The transgenic tomato fruit showed a significant reduction of lycopene and aroma volatiles with low ethylene production.6-methyl-5-hepten-2-one,6-methyl-5-hepten-2-ol and geranylacetone,which were suspected to be lycopene degradation products,were lower than those in wild type tomato fruits.In order to identify whether lycopene accumulation effects the biosynthesis of some carotenoid-related volatiles independent of ethylene in tomato or not,the capability of both wild type and transgenic tomato fruits discs to convert lycopene into carotenoid-related volatiles was evaluated.The data showed that external lycopene could convert into 6-methyl-5-hepten-2-one and 6-methyl-5-hepten-2-ol in vivo,Indicating that the strong inhibition of ethylene production had no effect on enzymes in the biosynthesis pathway of some carotenoid-related volatiles.Therefore,in ACS-suppression transgenic tomato fruits,the low levels of 6-methyl-5-hepten-2-one,6-methyl-5-hepten-2-ol was due to decreased lycopene accumulation,not ethylene production.Ethylene only affected the accumulation of lycopene,and then indirectly influenceed the level of lycopene-related volatiles.

  6. Accumulation of aluminium and iron by bryophytes in streams affected by acid-mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Engleman, C.J.; McDiffett, W.F. [Bucknell University, Lewisburg, PA (United States). Dept. of Biology

    1996-12-31

    This paper examines the accumulation of two heavy metals (Al and Fe) by bryophytes in a northern Pennsylvania stream system affected by acid-mine drainage. Four sites within one watershed were selected on the basis of their pH and dissolved metal concentrations. Significant differences among sites were found with regard to bioaccumulation of Al an Fe. A negative relationship between pH and Fe concentrations in bryophyte tissues was found, with the highest accumulation of Fe observed at the most acidic site (pH 3.5), whereas accumulation of Al was highest at a site with an intermediate pH of 5.2. Bryophytes transplanted from a circum-neutral site to acidic sites showed highly significant increases in Fe and Al concentrations in tissues after 6 weeks, and transplants from more acidic sites to a circum-neutral site generally showed highly significant declines in Fe and Al concentration in tissues after the incubation period.

  7. Glycogen distribution in the microwave-fixed mouse brain reveals heterogeneous astrocytic patterns.

    Science.gov (United States)

    Oe, Yuki; Baba, Otto; Ashida, Hitoshi; Nakamura, Kouichi C; Hirase, Hajime

    2016-09-01

    In the brain, glycogen metabolism has been implied in synaptic plasticity and learning, yet the distribution of this molecule has not been fully described. We investigated cerebral glycogen of the mouse by immunohistochemistry (IHC) using two monoclonal antibodies that have different affinities depending on the glycogen size. The use of focused microwave irradiation yielded well-defined glycogen immunoreactive signals compared with the conventional periodic acid-Schiff method. The IHC signals displayed a punctate distribution localized predominantly in astrocytic processes. Glycogen immunoreactivity (IR) was high in the hippocampus, striatum, cortex, and cerebellar molecular layer, whereas it was low in the white matter and most of the subcortical structures. Additionally, glycogen distribution in the hippocampal CA3-CA1 and striatum had a 'patchy' appearance with glycogen-rich and glycogen-poor astrocytes appearing in alternation. The glycogen patches were more evident with large-molecule glycogen in young adult mice but they were hardly observable in aged mice (1-2 years old). Our results reveal brain region-dependent glycogen accumulation and possibly metabolic heterogeneity of astrocytes. GLIA 2016;64:1532-1545. PMID:27353480

  8. Nitrogen (15N) accumulation in corn grains as affected by source of nitrogen in red latosol

    International Nuclear Information System (INIS)

    Nitrogen is the most absorbed mineral nutrient by corn crop and most affects grains yield. It is the unique nutrient absorbed by plants as cation (NH4+) or anion (NO3-). The objectives of this work were to investigate the N accumulation by corn grains applied to the soil as NH4+ or NO3- in the ammonium nitrate form compared to amidic form of the urea, labeled with 15N; to determine the corn growth stage with highest fertilizer N utilization by the grains, and to quantify soil nitrogen exported by corn grains. The study was carried out in the Experimental Station of the Regional Pole of the Sao Paulo Northwestern Agribusiness Development (APTA), in Votuporanga, State of Sao Paulo, Brazil, in a Red Latosol. The experimental design was completely randomized blocks, with 13 treatments and four replications, disposed in factorial outline 6x2 + 1 (control, without N application). A nitrogen rate equivalent to 120 kg N ha-1 as urea-15N or as ammonium nitrate, labeled in the cation NH4+ (15NH4+NO3-) or in the anion NO3- (NH4+15N+O3- ), was applied in six fractions of 20 kg N ha-1 each, in different microplots, from seeding to the growth stage 7 (pasty grains). The forms of nitrogen, NH4+-N and NO3--N, were accumulated equitably by corn grains. The corn grains accumulated more N from urea than from ammonium nitrate. The N applied to corn crop at eight expanded leaves stage promoted largest accumulation of this nutrient in the grains. (author)

  9. Glycogen synthase isoforms in Synechocystis sp. PCC6803: identification of different roles to produce glycogen by targeted mutagenesis.

    Directory of Open Access Journals (Sweden)

    Sang-Ho Yoo

    Full Text Available Synechocystis sp. PCC6803 belongs to cyanobacteria which carry out photosynthesis and has recently become of interest due to the evolutionary link between bacteria and plant species. Similar to other bacteria, the primary carbohydrate storage source of Synechocystis sp. PCC6803 is glycogen. While most bacteria are not known to have any isoforms of glycogen synthase, analysis of the genomic DNA sequence of Synechocystis sp. PCC6803 predicts that this strain encodes two isoforms of glycogen synthase (GS for synthesizing glycogen structure. To examine the functions of the putative GS genes, each gene (sll1393 or sll0945 was disrupted by double cross-over homologous recombination. Zymogram analysis of the two GS disruption mutants allowed the identification of a protein band corresponding to each GS isoform. Results showed that two GS isoforms (GSI and GSII are present in Synechocystis sp. PCC6803, and both are involved in glycogen biosynthesis with different elongation properties: GSI is processive and GSII is distributive. Total GS activities in the mutant strains were not affected and were compensated by the remaining isoform. Analysis of the branch-structure of glycogen revealed that the sll1393- mutant (GSI- produced glycogen containing more intermediate-length chains (DP 8-18 at the expense of shorter and longer chains compared with the wild-type strain. The sll0945- mutant (GSII- produced glycogen similar to the wild-type, with only a slightly higher proportion of short chains (DP 4-11. The current study suggests that GS isoforms in Synechocystis sp. PCC6803 have different elongation specificities in the biosynthesis of glycogen, combined with ADP-glucose pyrophosphorylase and glycogen branching enzyme.

  10. Sitamaquine-resistance in Leishmania donovani affects drug accumulation and lipid metabolism.

    Science.gov (United States)

    Imbert, L; Cojean, S; Libong, D; Chaminade, P; Loiseau, P M

    2014-09-01

    This study focuses on the mechanism of sitamaquine-resistance in Leishmania donovani. Sitamaquine accumulated 10 and 1.4 fold more in cytosol than in membranes of wild-type (WT) and of sitamaquine-resistant (Sita-R160) L. donovani promastigotes, respectively. The sitamaquine accumulation was a concentration-dependent process in WT whereas a saturation occurred in Sita-R160 suggesting a reduced uptake or an increase of the sitamaquine efflux. Membrane negative phospholipids being the main target for sitamaquine uptake, a lipidomic analysis showed that sitamaquine-resistance did not rely on a decrease of membrane negative phospholipid rate in Sita-R160, discarding the hypothesis of reduced uptake. However, sterol and phospholipid metabolisms were strongly affected in Sita-R160 suggesting that sitamaquine-resistance could be related to an alteration of phosphatidylethanolamine-N-methyl-transferase and choline kinase activities and to a decrease in cholesterol uptake and of ergosterol biosynthesis. Preliminary data of proteomics analysis exhibited different protein profiles between WT and Sita-160R remaining to be characterized. PMID:25201056

  11. Glycogen synthase activation in human skeletal muscle: effects of diet and exercise.

    Science.gov (United States)

    Kochan, R G; Lamb, D R; Lutz, S A; Perrill, C V; Reimann, E M; Schlender, K K

    1979-06-01

    We investigated the role of glycogen synthase in supranormal resynthesis (supercompensation) of skeletal muscle glycogen after exhaustive exercise. Six healthy men exercised 60 min by cycling with one leg at 75% VO2max, recovered 3 days on a low-carbohydrate diet, exercised again, and recovered 4 days on high-carbohydrate diet. Glycogen and glycogen synthase activities at several glucose-6-phosphate (G6P) concentrations were measured in biopsy samples of m. vastus lateralis. Dietary alterations alone did not affect glycogen, whereas exercise depleted glycogen stores. After the second exercise bout, glycogen returned to normal within 24 h and reached supercompensated levels by 48 h of recovery. Glycogen synthase activation state strikingly increased after exercise in exercised muscle and remained somewhat elevated for the first 48 h of recovery in both muscles. We suggest that 1) forms of glycogen synthase intermediate to I (G6P-independent) and D (G6P-dependent) forms are present in vivo, and 2) glycogen supercompensation can in part be explained by the formation of intermediate forms of glycogen synthase that exhibit relatively low activity ratios, but an increased sensitivity to activation by G6P. PMID:109015

  12. Hepatic Glycogen Supercompensation Activates AMP-Activated Protein Kinase, Impairs Insulin Signaling, and Reduces Glycogen Deposition in the Liver

    OpenAIRE

    Winnick, Jason J.; An, Zhibo; Ramnanan, Christopher J.; Smith, Marta; Irimia, Jose M.; Neal, Doss W.; Moore, Mary Courtney; Peter J Roach; Cherrington, Alan D.

    2011-01-01

    OBJECTIVE The objective of this study was to determine how increasing the hepatic glycogen content would affect the liver’s ability to take up and metabolize glucose. RESEARCH DESIGN AND METHODS During the first 4 h of the study, liver glycogen deposition was stimulated by intraportal fructose infusion in the presence of hyperglycemic-normoinsulinemia. This was followed by a 2-h hyperglycemic-normoinsulinemic control period, during which the fructose infusion was stopped, and a 2-h experiment...

  13. Muscle glycogen stores and fatigue

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Westerblad, Håkan; Nielsen, Joachim

    2013-01-01

      Studies performed at the beginning of the last century revealed the importance of carbohydrate as a fuel during exercise, and the importance of muscle glycogen on performance has subsequently been confirmed in numerous studies. However, the link between glycogen depletion and impaired muscle...... function during fatigue is not well understood and a direct cause-and-effect relationship between glycogen and muscle function remains to be established. The use of electron microscopy has revealed that glycogen is not homogeneously distributed in skeletal muscle fibres, but rather localized in distinct...... pools. Furthermore, each glycogen granule has its own metabolic machinery with glycolytic enzymes and regulating proteins. One pool of such glycogenolytic complexes is localized within the myofibrils in close contact with key proteins involved in the excitation-contraction coupling and Ca2+ release from...

  14. Denitrification characteristics and community distribution of glycogen accumulating organism granules%聚糖菌颗粒污泥的反硝化特性与微生物群落分布

    Institute of Scientific and Technical Information of China (English)

    张斌; 邱志刚; 薛斌; 谌志强; 龚泰石; 王雪; 智维佳; 王景峰

    2014-01-01

    This study aimed to investigate the denitrification ability and microbial ecological characteristic of glycogen-accumulating organisms (GAOs) during sludge granulation.A combined method of reactor process,batch test,microscale techniques and fluorescence in situ hybridization (FISH) was employed to evaluate the denitrification ability of GAOs,to reveal the microstructure of microbial communities and to characterize the distribution of GAOs and polyphosphate-accumulating organisms (PAOs) in different size granules.The results indicated that the adsorption rate of organic compound by sludge was over 92%.The SVI10 of granules stabilized at 30-50 mL g-1,a very low value compared to those measured for inoculating sludge (108.2 mL g-1).The nitrogen removal rate of nitrate and nitrite by GAOs granules reached 65% and 70% respectively,with N2 as the main gaseous product.The granules were tightly packed with a large amount of tetrad-forming organisms (TFOs),with filamentous bacteria serving as the supporting structures for the granules.FISH demonstrated that GAOs were distributed evenly throughout the granular space,whereas PAOs were severely inhibited and presented only in the edge of granules.A labscale sequencing batch reactor (SBR) could be successfully operated for cultivating GAOs granules in alternating anaerobic stirring-discharge-aerobic modes,with the GAOs granules showing excellent denitrifying capability.Therefore GAOs are the predominant member of the microbial population in granules.%为了解聚糖菌在污泥颗粒化中的脱氮能力及其微生物生态特性,采用反应器工艺、批式试验、显微技术和荧光原位杂交技术来评估其反硝化能力,揭示其微生物群落的微观结构,探索聚糖菌和聚磷菌在不同粒径污泥中的分布特征.结果表明,污泥对有机物的吸收率稳定在90%以上.颗粒污泥的沉降指数(SVI10)稳定在30-50 mL g-1,远低于接种污泥的108.2 mL g-1.聚醣菌颗粒污泥对

  15. Sodium-Glucose Cotransporter 2 Inhibitor and a Low Carbohydrate Diet Affect Gluconeogenesis and Glycogen Content Differently in the Kidney and the Liver of Non-Diabetic Mice

    OpenAIRE

    Atageldiyeva, Kuralay; Fujita, Yukihiro; Yanagimachi, Tsuyoshi; Mizumoto, Katsutoshi; Takeda, Yasutaka; Honjo, Jun; Takiyama, Yumi; Abiko, Atsuko; Makino, Yuichi; Haneda, Masakazu

    2016-01-01

    A low carbohydrate diet (LCHD) as well as sodium glucose cotransporter 2 inhibitors (SGLT2i) may reduce glucose utilization and improve metabolic disorders. However, it is not clear how different or similar the effects of LCHD and SGLT2i are on metabolic parameters such as insulin sensitivity, fat accumulation, and especially gluconeogenesis in the kidney and the liver. We conducted an 8-week study using non-diabetic mice, which were fed ad-libitum with LCHD or a normal carbohydrate diet (NCH...

  16. Seasonal Changes in Glycogen Contents in Various Tissues of the Edible Bivalves, Pen Shell Atrina lischkeana, Ark Shell Scapharca kagoshimensis, and Manila Clam Ruditapes philippinarum in West Japan

    OpenAIRE

    Tatsuya Yurimoto

    2015-01-01

    The types of tissues accumulating glycogen and seasonal changes in glycogen content were investigated in the following shell species: pen shell Atrina lischkeana, ark shell Scapharca kagoshimensis, and Manila clam Ruditapes philippinarum. Comparison of the results showed that the adductor muscle or foot was the main glycogen reservoir and the levels varied seasonally. The adductor muscle in the pen shell showed higher glycogen content during spring and lower content during autumn. The ark she...

  17. Possible mechanism for changes in glycogen metabolism in unloaded soleus muscle

    Science.gov (United States)

    Henriksen, E. J.; Tischler, M. E.

    1985-01-01

    Carbohydrate metabolism has been shown to be affected in a number of ways by different models of hypokinesia. In vivo glycogen levels in the soleus muscle are known to be increased by short-term denervation and harness suspension. In addition, exposure to 7 days of hypogravity also caused a dramatic increase in glycogen concentration in this muscle. The biochemical alterations caused by unloading that may bring about these increases in glycogen storage in the soleus were sought.

  18. Accumulation of distinct prelamin A variants in human diploid fibroblasts differentially affects cell homeostasis

    Energy Technology Data Exchange (ETDEWEB)

    Candelario, Jose; Borrego, Stacey [Department of Molecular Microbiology and Immunology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Reddy, Sita, E-mail: sitaredd@usc.edu [Department of Biochemistry and Molecular Biology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Comai, Lucio, E-mail: comai@usc.edu [Department of Molecular Microbiology and Immunology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)

    2011-02-01

    levels of the basal transcription factor TATA-binding protein (TBP) and global transcription, and severely limited cell growth. Expression of a prelamin A variant that cannot be farnesylated, although did not appreciably influence cell growth, resulted in the formation of lamin A nucleoplasmic foci and caused, in a minor subpopulation of cells, changes in nuclear morphology that were accompanied by reduced levels of TBP and transcription. In contrast, expression of mature lamin A did not affect any of these parameters. These data demonstrate that accumulation of any partially processed prelamin A protein alters cellular homeostasis to some degree, even though the most dramatic effects are caused by variants with a permanently farnesylated carboxyl-terminal tail.

  19. Arsenic accumulation in rice grains as affected by cultivars and water management practices

    Science.gov (United States)

    Arsenic (As) accumulation in rice grains is a threat to human health and marketability of rice products. The accumulation has been linked to the elevated As in soil resulting from pesticide application and/or irrigation water quality. In an effort to minimize As uptake by rice grain and occurrence o...

  20. Muscle glycogen supercompensation: absence of a gender-related difference.

    Science.gov (United States)

    James, A P; Lorraine, M; Cullen, D; Goodman, C; Dawson, B; Palmer, T N; Fournier, P A

    2001-10-01

    Recently it has been reported that women do not have the capacity to accumulate supranormal levels of muscle glycogen when subjected to a carbohydrate (CHO) loading regimen [Tarnopolsky et al. (1995) J Appl Physiol 78:1360-1368]. Since, in this study, CHO intake relative to body mass in the female subjects was much lower than that in males, our primary aim was to re-examine this issue using subjects fed comparable amounts of CHO. Endurance-trained female and male subjects ingested 12 g CHO x kg(-1) lean body mass day(-1) in conjunction with the cessation of their daily physical training. A 3-day exposure to this diet resulted in a marked rise in muscle glycogen levels from [mean (SD)] 108 (15) mmol x kg(-1) wet weight to 193 (14) mmol x kg(-1) wet weight and 111 (16) m mol x kg(-1) wet weight to 202 (20) mmol x kg(-1) wet weight in the female participants during the post-menstrual and pre-menstrual phases of their menstrual cycle, respectively, and from 109 (27) mmol x kg(-1) wet weight to 183 (25) mmol x kg(-1) wet weight in males. We conclude that (1) female athletes have the capacity to accumulate supranormal levels of muscle glycogen, and (2) when exercise-trained males and females are fed comparable amounts of CHO relative to lean body mass, there is no gender-related difference in their ability to accumulate supranormal levels of muscle glycogen. PMID:11718281

  1. Effect of pH on Cleavage of Glycogen by Vaginal Enzymes

    OpenAIRE

    Spear, Greg T.; McKenna, Mary; Landay, Alan L.; Makinde, Hadijat; Hamaker, Bruce; French, Audrey L.; Lee, Byung-Hoo

    2015-01-01

    Glycogen expressed by the lower genital tract epithelium is believed to support Lactobacillus growth in vivo, although most genital isolates of Lactobacillus are not able to use glycogen as an energy source in vitro. We recently reported that α-amylase is present in the genital fluid of women and that it breaks down glycogen into small carbohydrates that support growth of lactobacilli. Since the pH of the lower genital tract can be very low, we determined how low pH affects glycogen processin...

  2. Sodium valproate increases the brain isoform of glycogen phosphorylase: looking for a compensation mechanism in McArdle disease using a mouse primary skeletal-muscle culture in vitro

    Directory of Open Access Journals (Sweden)

    Noemí de Luna

    2015-05-01

    Full Text Available McArdle disease, also termed ‘glycogen storage disease type V’, is a disorder of skeletal muscle carbohydrate metabolism caused by inherited deficiency of the muscle-specific isoform of glycogen phosphorylase (GP-MM. It is an autosomic recessive disorder that is caused by mutations in the PYGM gene and typically presents with exercise intolerance, i.e. episodes of early exertional fatigue frequently accompanied by rhabdomyolysis and myoglobinuria. Muscle biopsies from affected individuals contain subsarcolemmal deposits of glycogen. Besides GP-MM, two other GP isoforms have been described: the liver (GP-LL and brain (GP-BB isoforms, which are encoded by the PYGL and PYGB genes, respectively; GP-BB is the main GP isoform found in human and rat foetal tissues, including the muscle, although its postnatal expression is dramatically reduced in the vast majority of differentiated tissues with the exception of brain and heart, where it remains as the major isoform. We developed a cell culture model from knock-in McArdle mice that mimics the glycogen accumulation and GP-MM deficiency observed in skeletal muscle from individuals with McArdle disease. We treated mouse primary skeletal muscle cultures in vitro with sodium valproate (VPA, a histone deacetylase inhibitor. After VPA treatment, myotubes expressed GP-BB and a dose-dependent decrease in glycogen accumulation was also observed. Thus, this in vitro model could be useful for high-throughput screening of new drugs to treat this disease. The immortalization of these primary skeletal muscle cultures could provide a never-ending source of cells for this experimental model. Furthermore, VPA could be considered as a gene-expression modulator, allowing compensatory expression of GP-BB and decreased glycogen accumulation in skeletal muscle of individuals with McArdle disease.

  3. Glycogen supercompensation in rat soleus muscle during recovery from nonweight bearing

    Science.gov (United States)

    Henriksen, Erik J.; Kirby, Christopher R.; Tischler, Marc E.

    1989-01-01

    Events leading to the normalization of the glycogen metabolism in the soleus muscle of rat, altered by 72-h three days of hind-limb suspension, were investigated during the 72-h recovery period when the animals were allowed to bear weight on all four limbs. Relative importance of the factors affecting glycogen metabolism in skeletal muscle during the recovery period was also examined. Glycogen concentration was found to decrease within 15 min and up to 2 h of recovery, while muscle glucose 6-phosphate, and the fractional activities of glycogen phosphorylase and glycogen synthase increased. From 2 to 4 h, when the glycogen synthase activity remained elevated and the phosphorylase activity declined, glycogen concentration increased, until it reached maximum values at about 24 h, after which it started to decrease, reaching control values by 72 h. At 12 and 24 h, the inverse relationship between glycogen concentration and the synthase activity ratio was lost, indicating that the reloading transiently uncoupled glycogen control of this enzyme.

  4. Differential response of rat cardiac and skeletal muscle glycogen to glucocorticoids.

    Science.gov (United States)

    Poland, J L; Poland, J W; Honey, R N

    1982-05-01

    Though glucocorticoids were previously implicated in the support of myocardial glycogen supercompensation after exercise, it was unclear why skeletal muscle glycogen did not simultaneously supercompensate since it was also exposed to the exercise-induced glucocorticoid increases. The current study shows that glucocorticoids differentially affect cardiac and skeletal muscle glycogen. Following dexamethasone administration (400 micrograms i.p.) myocardial glycogen peaked at 6 h while glycogen in the soleus, red vastus lateralis, and white vastus lateralis increased more slowly and reached the highest values 17 h postinjection. Concurrently, blood glucose, insulin, and glucagon remained at control levels. Liver glycogen increased within 2 h and continued to rise with a peak value at 17 h. Plasma free fatty acid (FFA) levels increased and remained high throughout the 26-h experimental period. High FFA levels inhibit glycogenolysis and thus could be partially responsible for glucocorticoid-induced glycogen increases. It is postulated that glycogen supercompensation does not readily occur in skeletal muscles after exercise because of the brevity of the corticosterone and FFA increases and the slowness of the skeletal muscle glycogen response to glucocorticoids. PMID:7104851

  5. Factors Affecting Wealth Accumulation in Hispanic Households: A Comparative Analysis of Stock and Home Asset Utilization

    Science.gov (United States)

    Fontes, Angela; Kelly, Nicole

    2013-01-01

    This research addresses differences between Hispanic ("N" = 2,333) and White ("N" = 15,521) households in the ownership and allocation of two representative measures of wealth accumulation, stock and homeownership. Using data from the 2008 panel of the Survey of Income and Program Participation, this research estimates a…

  6. Soil and Sediment Properties Affecting the Transport and Accumulations of Mercury in a Flood Control Reservoir

    Science.gov (United States)

    Mercury accumulations in some fish species from Grenada Lake in north Mississippi exceed the Food and Drug Administration standards for human consumption. This large flood control reservoir serves as a sink for the Skuna and Yalobusha River watersheds whose highly erodible soils contribute to exces...

  7. Hexokinase 2, glycogen synthase and phosphorylase play a key role in muscle glycogen supercompensation

    DEFF Research Database (Denmark)

    Irimia, José M; Rovira, Jordi; Nielsen, Jakob N; Guerrero, Mario; Wojtaszewski, Jørgen; Cussó, Roser

    2012-01-01

    Glycogen-depleting exercise can lead to supercompensation of muscle glycogen stores, but the biochemical mechanisms of this phenomenon are still not completely understood.......Glycogen-depleting exercise can lead to supercompensation of muscle glycogen stores, but the biochemical mechanisms of this phenomenon are still not completely understood....

  8. Analysis of two single trait loci affecting flavonol glycoside accumulations in Arabidopsis thaliana natural variations

    OpenAIRE

    Ishihara, Hirofumi

    2007-01-01

    Various plant secondary metabolites, including flavonoids, are involved in plant adaptation to different environments. The needs of sessile lifestyle of plants may have increased the variation of enzymes which are required in the modification and/or accumulation of different flavonol derivatives. The probable mechanism for generating variants of the enzymes is by mutating the corresponding genes. Therefore, Arabidopsis thaliana wildtype accessions collected from different environments and loc...

  9. Water Management Practices Affect Arsenic and Cadmium Accumulation in Rice Grains

    Directory of Open Access Journals (Sweden)

    Liming Sun

    2014-01-01

    Full Text Available Cadmium (Cd and arsenic (As accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously.

  10. Mould Growth and Aflatoxin Accumulation Affected by Newly Synthesized Derivative of Coumarine Treatment of Maize Hybrid

    Directory of Open Access Journals (Sweden)

    Lejla Duraković

    2014-02-01

    Full Text Available The effect of newly synthesized derivative of 11-hydroxy-7-imino-7H-7a, 12-diazabenzo/α/anthracen-6-one, on growth and aflatoxin B1 and G1 (AFB1 and AFG1 accumulation by toxigenic mould Aspergillus fl avus ATCC 26949 was studied on a solid substrate (maize grains to determine the possible use of this compound as a mean of controlling aflatoxin accumulation. Experiments were carried out in a stationary culture at temperature of 28oC during 21 days. The growth of mould was monitored by measuring the analysis of chitin as glucosamine, as a criterion, and concentration of AFB1 and AFG1 was measured by HPLC method using Hewlett-Packard instrument with fluorescence detector. Concentration of investigated coumarine of 0.05 mmol x g-1 stimulated mould growth and aflatoxin accumulation, but concentration of 0.2 mmol x g-1 or higher produced an inhibitory effect. In the presence of 0.2 and 0.5 mmol x g-1 of this compound, mould growth was decreased by 22% and 65%, respectively. Concentration of AFB1 in these investigations was reduced by 30% and 90%, and concentration of AFG1 was reduced almost completely in respect to values obtained in control experiments. In experiments with 2.0 mmol x g-1 of this inhibitor no synthesis of both investigated aflatoxins was found in the sample although small increment of biomass was detected.

  11. A glycogene mutation map for discovery of diseases of glycosylation

    DEFF Research Database (Denmark)

    Hansen, Lars; Lind-Thomsen, Allan; Joshi, Hiren J;

    2015-01-01

    Glycosylation of proteins and lipids involves over 200 known glycosyltransferases, and deleterious defects in many of the genes encoding these enzymes cause disorders collectively classified as Congenital Disorders of Glycosylation (CDGs). Most known CDGs are caused by defects in glycogenes that...... effects glycosylation globally. Many glycosyltransferases are members of homologous isoenzyme families and deficiencies in individual isoenzymes may not affect glycosylation globally. In line with this there appears to be an underrepresentation of disease-causing glycogenes among these larger isoenzyme...... populations, which can be used to predict and/or analyze functional deleterious mutations. Here, we constructed a draft of a Functional Mutational Map of glycogenes, GlyMAP, from WES of a rather homogenous population of 2,000 Danes. We catalogued all missense mutations and used prediction algorithms, manual...

  12. Study of Plant Cell Wall Polymers Affected by Metal Accumulation Using Stimulated Raman Scattering Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shi-You [Harvard Univ., Cambridge, MA (United States)

    2015-03-02

    This project aims to employ newly-developed chemical imaging techniques to measure, in real-time, the concentration, dynamics and spatial distribution of plant cell wall polymers during biomass growth with inoculation of transgenic symbiotic fungi, and to explore a new pathway of delivering detoxified metal to plant apoplast using transgenic symbiotic fungi, which will enhance metal accumulation from soil, and potentially these metals may in turn be used as catalysts to improve the efficiency of biomass conversion to biofuels. The proposed new pathway of biomass production will: 1) benefit metal and radionuclide contaminant mobility in subsurface environments, and 2) potentially improve biomass production and process for bioenergy

  13. Prevention of glycogen supercompensation prolongs the increase in muscle GLUT4 after exercise.

    Science.gov (United States)

    Garcia-Roves, Pablo M; Han, Dong-Ho; Song, Zheng; Jones, Terry E; Hucker, Kathleen A; Holloszy, John O

    2003-10-01

    Exercise induces an increase in GLUT4 in skeletal muscle with a proportional increase in glucose transport capacity. This adaptation results in enhanced glycogen accumulation, i.e., "supercompensation," in response to carbohydrate feeding after glycogen-depleting exercise. The increase in GLUT4 reverses within 40 h after exercise in carbohydrate-fed rats. The purpose of this study was to determine whether prevention of skeletal muscle glycogen supercompensation after exercise results in maintenance of the increases in GLUT4 and the capacity for glycogen supercompensation. Rats were exercised by means of three daily bouts of swimming. GLUT4 mRNA was increased approximately 3-fold and GLUT4 protein was increased approximately 2-fold 18 h in epitrochlearis muscle after exercise. These increases in GLUT4 mRNA and protein reversed completely within 42 h after exercise in rats fed a high-carbohydrate diet. In contrast, the increases in GLUT4 protein, insulin-stimulated glucose transport, and increased capacity for glycogen supercompensation persisted unchanged for 66 h in rats fed a carbohydrate-free diet that prevented glycogen supercompensation after exercise. GLUT4 mRNA was still elevated at 42 h but had returned to baseline by 66 h after exercise in rats fed the carbohydrate-free diet. Glycogen-depleted rats fed carbohydrate 66 h after exercise underwent muscle glycogen supercompensation with concomitant reversal of the increase in GLUT4. These findings provide evidence that prevention of glycogen supercompensation after exercise results in persistence of exercise-induced increases in GLUT4 protein and enhanced capacity for glycogen supercompensation. PMID:12799316

  14. Seasonal Changes in Glycogen Contents in Various Tissues of the Edible Bivalves, Pen Shell Atrina lischkeana, Ark Shell Scapharca kagoshimensis, and Manila Clam Ruditapes philippinarum in West Japan

    Directory of Open Access Journals (Sweden)

    Tatsuya Yurimoto

    2015-01-01

    Full Text Available The types of tissues accumulating glycogen and seasonal changes in glycogen content were investigated in the following shell species: pen shell Atrina lischkeana, ark shell Scapharca kagoshimensis, and Manila clam Ruditapes philippinarum. Comparison of the results showed that the adductor muscle or foot was the main glycogen reservoir and the levels varied seasonally. The adductor muscle in the pen shell showed higher glycogen content during spring and lower content during autumn. The ark shell, on the other hand, showed higher content during winter and spring and lower content during summer and autumn, while the Manila clam showed higher glycogen content during spring and summer and lower content during autumn and winter. These results revealed that the adductor muscle in pen shells and the foot in ark shells and Manila clams act as the main storage tissues for glycogen in the three species studied and that these tissues are suitable to analyze glycogen prevalence to estimate individual physiological condition.

  15. Robust glycogen shunt activity in astrocytes: Effects of glutamatergic and adrenergic agents.

    Science.gov (United States)

    Walls, A B; Heimbürger, C M; Bouman, S D; Schousboe, A; Waagepetersen, H S

    2009-01-12

    The significance and functional roles of glycogen shunt activity in the brain are largely unknown. It represents the fraction of metabolized glucose that passes through glycogen molecules prior to entering the glycolytic pathway. The present study was aimed at elucidating this pathway in cultured astrocytes from mouse exposed to agents such as a high [K+], D-aspartate and norepinephrine (NE) known to affect energy metabolism in response to neurotransmission. Glycogen shunt activity was assessed employing [1,6-13C]glucose, and the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) to block glycogen degradation. The label intensity in lactate, reflecting glycolytic activity, was determined by mass spectrometry. In the presence of NE a substantial glycogen shunt activity was observed, accounting for almost 40% of overall glucose metabolism. Moreover, when no metabolic stimulant was applied, a compensatory increase in glycolytic activity was seen when the shunt was inhibited by DAB. Actually the labeling in lactate exceeded that obtained when glycolysis and glycogen shunt both were operational, i.e. supercompensation. A similar phenomenon was seen when astrocytes were exposed to D-aspartate. In addition to glycolysis, tricarboxylic acid (TCA) cycle activity was monitored, analyzing labeling by mass spectrometry in glutamate which equilibrates with alpha-ketoglutarate. Both an elevated [K+] and D-aspartate induced an increased TCA cycle activity, which was altered when glycogen degradation was inhibited. Thus, the present study provides evidence that manipulation of glycogen metabolism affects both glycolysis and TCA cycle metabolism. Altogether, the results reveal a highly complex interaction between glycogenolysis and glycolysis, with the glycogen shunt playing a significant role in astrocytic energy metabolism. PMID:19000744

  16. Zeaxanthin biofortification of sweet-corn and factors affecting zeaxanthin accumulation and colour change.

    Science.gov (United States)

    O'Hare, Tim J; Fanning, Kent J; Martin, Ian F

    2015-04-15

    Zeaxanthin, along with its isomer lutein, are the major carotenoids contributing to the characteristic colour of yellow sweet-corn. From a human health perspective, these two carotenoids are also specifically accumulated in the human macula, and are thought to protect the photoreceptor cells of the eye from blue light oxidative damage and to improve visual acuity. As humans cannot synthesise these compounds, they must be accumulated from dietary components containing zeaxanthin and lutein. In comparison to most dietary sources, yellow sweet-corn (Zea mays var. rugosa) is a particularly good source of zeaxanthin, although the concentration of zeaxanthin is still fairly low in comparison to what is considered a supplementary dose to improve macular pigment concentration (2mg/person/day). In our present project, we have increased zeaxanthin concentration in sweet-corn kernels from 0.2 to 0.3mg/100g FW to greater than 2.0mg/100g FW at sweet-corn eating-stage, substantially reducing the amount of corn required to provide the same dosage of zeaxanthin. This was achieved by altering the carotenoid synthesis pathway to more than double total carotenoid synthesis and to redirect carotenoid synthesis towards the β-arm of the pathway where zeaxanthin is synthesised. This resulted in a proportional increase of zeaxanthin from 22% to 70% of the total carotenoid present. As kernels increase in physiological maturity, carotenoid concentration also significantly increases, mainly due to increased synthesis but also due to a decline in moisture content of the kernels. When fully mature, dried kernels can reach zeaxanthin and β-carotene concentrations of 8.7 mg/100g and 2.6 mg/100g, respectively. Although kernels continue to increase in zeaxanthin when harvested past their normal harvest maturity stage, the texture of these 'over-mature' kernels is tough, making them less appealing for fresh consumption. Increase in zeaxanthin concentration and other orange carotenoids such as

  17. Growth, Cadmium Accumulation and Physiology of Marigold (Tagetes erecta L.) as Affected by Arbuscular Mycorrhizal Fungi

    Institute of Scientific and Technical Information of China (English)

    LIU Ling-Zhi; GONG Zong-Qiang; ZHANG Yu-Long; LI Pei-Jun

    2011-01-01

    A pot experiment was carried out to study the effects of three arbuscular mycorrhizal fungi (AMF), including Glomus intraradices, Glomus constrictum and Glomus mosseae, on the growth, root colonization and Cd accumulation of marigold (Tagetes erecta L.) at Cd addition levels of 0, 5 and 50 mg kg-1 in soil. The physiological characteristics, such as chlorophyll content, soluble sugar content, soluble protein content and antioxidant enzyme activity, of Tagetes erecta L. were also investigated. The symbiotic relationship between the marigold plant and arbuscular mycorrhizal fungi was well established under Cd stress. The symbiotic relationship was reflected by the better physiobiochemical parameters of the marigold plants inoculated with the three AMF isolates where the colonization rates in the roots were between 34.3% and 88.8%. Compared with the non-inoculated marigold plants, the shoot and root biomass of the inoculated marigold plants increased by 15.2%-47.5% and 47.8%-130.1%, respectively, and the Cd concentration and accumulation decreased. The chlorophyll and soluble sugar contents in the mycorrhizal marigold plants increased with Cd addition, indicating that AMF inoculation helped the marigold plants to grow by resisting Cd stress. The antioxidant enzymes reacted differently with the three AMF under Cd stress. For plants inoculated with G. constrictum and G. mosseae, the activities of superoxide dismutase (SOD) and catalase (CAT) increased with increasing Cd addition, but peroxidase (POD) activity decreased with increasing Cd addition. For plants inoculated with G. intruradices, three of the antioxidant enzyme activities were significantly decreased at high levels of Cd addition. Overall, the activities of the three antioxidant enzymes in the plants inoculated with AMF were higher than those of the plants without AMF inoculation under Cd stress. Our results support the view that antioxidant enzymes have a great influence on the biomass of plants

  18. [3H] glycogen hydrolysis in brain slices: responses to meurotransmitters and modulation of noradrenaline receptors

    International Nuclear Information System (INIS)

    Different agents have been investigated for their effects on [3H] glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration-dependent glycogenesis. [3H] glycogen hydrolysis induced by noradrenaline appears to be mediated by beta-adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis. Lower concentrations of noradrenaline were necessary for [3H] glycogen hydrolysis (ECsub(50) 0.5μM) than for stimulation of cyclic AMP accumulation (ECsub(50) = 8μM). After subchronic reserpine treatment the concentration-response curve to noradrenaline was significantly shifted to the left (ECsub(50) = 0.09 +- 0.02 μM as compared with 0.49 +- 0.08μM in saline-pretreated mice) without modifications of either the basal [3H] glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP-induced glycogenolytic response. In addition to noradrenaline, clear concentration-dependent [3H] glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [3H] glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K+ provoked a nearly total [3H] glycogen hydrolysis. (author)

  19. Paclitaxel loading in PLGA nanospheres affected the in vitro drug cell accumulation and antiproliferative activity

    International Nuclear Information System (INIS)

    PTX is one of the most widely used drug in oncology due to its high efficacy against solid tumors and several hematological cancers. PTX is administered in a formulation containing 1:1 Cremophor® EL (polyethoxylated castor oil) and ethanol, often responsible for toxic effects. Its encapsulation in colloidal delivery systems would gain an improved targeting to cancer cells, reducing the dose and frequency of administration. In this paper PTX was loaded in PLGA NS. The activity of PTX-NS was assessed in vitro against thyroid, breast and bladder cancer cell lines in cultures. Cell growth was evaluated by MTS assay, intracellular NS uptake was performed using coumarin-6 labelled NS and the amount of intracellular PTX was measured by HPLC. NS loaded with 3% PTX (w/w) had a mean size < 250 nm and a polydispersity index of 0.4 after freeze-drying with 0.5% HP-Cyd as cryoprotector. PTX encapsulation efficiency was 30% and NS showed a prolonged drug release in vitro. An increase of the cytotoxic effect of PTX-NS was observed with respect to free PTX in all cell lines tested. These findings suggest that the greater biological effect of PTX-NS could be due to higher uptake of the drug inside the cells as shown by intracellular NS uptake and cell accumulation studies

  20. Paclitaxel loading in PLGA nanospheres affected the in vitro drug cell accumulation and antiproliferative activity

    Directory of Open Access Journals (Sweden)

    De Maria Ruggero

    2008-07-01

    Full Text Available Abstract Background PTX is one of the most widely used drug in oncology due to its high efficacy against solid tumors and several hematological cancers. PTX is administered in a formulation containing 1:1 Cremophor® EL (polyethoxylated castor oil and ethanol, often responsible for toxic effects. Its encapsulation in colloidal delivery systems would gain an improved targeting to cancer cells, reducing the dose and frequency of administration. Methods In this paper PTX was loaded in PLGA NS. The activity of PTX-NS was assessed in vitro against thyroid, breast and bladder cancer cell lines in cultures. Cell growth was evaluated by MTS assay, intracellular NS uptake was performed using coumarin-6 labelled NS and the amount of intracellular PTX was measured by HPLC. Results NS loaded with 3% PTX (w/w had a mean size Conclusion These findings suggest that the greater biological effect of PTX-NS could be due to higher uptake of the drug inside the cells as shown by intracellular NS uptake and cell accumulation studies.

  1. Cadmium accumulation in Panax notoginseng: levels, affecting factors and the non-carcinogenic health risk.

    Science.gov (United States)

    Zhu, Meilin; Jiang, Yang; Cui, Bin; Jiang, Yanxue; Cao, Hongbin; Zhang, Wensheng

    2016-04-01

    Cadmium (Cd) contamination has been reported to be a problem for the safe usage of Panax notoginseng (Sanchi); thus, it is necessary to elucidate the Cd accumulation in Sanchi and to assess its associated health risk. Samples were collected from major producing areas in Yunnan, China. The average concentration of Cd in Sanchi was 0.43 mg/kg, which exceeds the standard level for herbal medicine in China (0.3 mg/kg). A stepwise regression analysis showed that zinc and the pH were the related factors that most significantly impacted Cd in Sanchi roots. The hazard quotient values were estimated as 0.0010 (men) and 0.0012 (women) for consumers taking preparations and were 0.011 (men) and 0.013 (women) for consumers taking health products, implying that there is no non-carcinogenic hazard associated with Sanchi consumption. However, a Monte Carlo simulation showed that approximately 0.80 % of male and 1.02 % of female consumers via drug consumption and 36.28 % of male and 41.87 % of female consumers via health product consumption had an exposure exceeding the acceptable daily intake (ADI) of Cd from drugs (1 % of the total oral ADI as suggested by the World Health Organization). These people should control their oral Cd intake from both Sanchi consumption and diet as a whole. PMID:26070861

  2. Hydroperiod affects nutrient accumulation in tree islands of the Florida Everglades: a stable isotope study

    Science.gov (United States)

    Wang, X.; Sternberg, L. O.; Engel, V.; Ross, M. S.

    2009-12-01

    Tree islands are important and unique components of wetland ecosystems. In many cases they are the end product of self organizing vegetation systems, which are often characterized by uneven soil nutrient distributions. Tree islands in the Everglades are phosphorus rich in contrast to the phosphorus-poor surrounding vegetation matrix. Everglades tree islands occur in the ridge-slough habitat of Shark River Slough, which is characterized by deep organic soils, multi-year hydroperiods, and maximum water depths of ~ 1 m. Tree islands are also found in the drier marl prairie habitat of the Everglades, characterized by marl soils, shallow water (Shark River Slough and adjacent prairie landscapes. We observed that prairie tree islands suffer greater drought stress during the dry season than slough tree islands by examining shifts in foliar δ13C values. We also found that slough tree islands have higher soil total phosphorus concentration and lower foliar N/P ratio than prairie tree islands. Foliar δ15N values, which often increase with greater P availability, was also found to be higher in slough tree islands than in prairie tree islands. Both the elemental N and P and foliar δ15N results indicate that the upland hammock plant communities in slough tree islands have higher amount of P available than those in prairie tree islands. Our findings are consistent with the transpiration driven nutrient harvesting chemohydrodynamic model. Tree islands without drought stress hypothetically transpire more and harvest more P than tree islands that have drought stress during the dry season. These findings suggest that hydroperiod is important to nutrient accumulation of tree island habitats and to the self-organization of the Everglades landscape.

  3. Brain glycogen decreases during prolonged exercise

    Science.gov (United States)

    Matsui, Takashi; Soya, Shingo; Okamoto, Masahiro; Ichitani, Yukio; Kawanaka, Kentaro; Soya, Hideaki

    2011-01-01

    Abstract Brain glycogen could be a critical energy source for brain activity when the glucose supply from the blood is inadequate (hypoglycaemia). Although untested, it is hypothesized that during prolonged exhaustive exercise that induces hypoglycaemia and muscular glycogen depletion, the resultant hypoglycaemia may cause a decrease in brain glycogen. Here, we tested this hypothesis and also investigated the possible involvement of brain monoamines with the reduced levels of brain glycogen. For this purpose, we exercised male Wistar rats on a treadmill for different durations (30–120 min) at moderate intensity (20 m min−1) and measured their brain glycogen levels using high-power microwave irradiation (10 kW). At the end of 30 and 60 min of running, the brain glycogen levels remained unchanged from resting levels, but liver and muscle glycogen decreased. After 120 min of running, the glycogen levels decreased significantly by ∼37–60% in five discrete brain loci (the cerebellum 60%, cortex 48%, hippocampus 43%, brainstem 37% and hypothalamus 34%) compared to those of the sedentary control. The brain glycogen levels in all five regions after running were positively correlated with the respective blood and brain glucose levels. Further, in the cortex, the levels of methoxyhydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), potential involved in degradation of the brain glycogen, increased during prolonged exercise and negatively correlated with the glycogen levels. These results support the hypothesis that brain glycogen could decrease with prolonged exhaustive exercise. Increased monoamines together with hypoglycaemia should be associated with the development of decreased brain glycogen, suggesting a new clue towards the understanding of central fatigue during prolonged exercise. PMID:21521757

  4. Studies in tissue glycogen in acute stress.

    Science.gov (United States)

    De, A K; Dey, C; Debnath, P K

    1978-01-01

    The glycogen was estimated in liver, cardiac and skeletal muscles during the recovery period after electro-shock. The supercompensation in the level of glycogen was observed in cardiac and skeletal muscles at 1 1/2 and 5 hrs respectively during the recovery period, after electro-shock. The liver glycogen level was lower than the control value after electro-shock at least upto 5 hrs of recovery period. Further, the glycogen level was observed to be minimum when the ventricular glycogen showed its supercompensation at 1 1/2 hr of recovery period. The glycogen level of those three tissues returned to control level after 24 hrs of electro-shock. PMID:567192

  5. Characterization of a canine model of glycogen storage disease type IIIa

    OpenAIRE

    Yi, Haiqing; Thurberg, Beth L.; Curtis, Sarah; Austin, Stephanie; Fyfe, John; Koeberl, Dwight D.; Kishnani, Priya S.; Sun, Baodong

    2012-01-01

    SUMMARY Glycogen storage disease type IIIa (GSD IIIa) is an autosomal recessive disease caused by deficiency of glycogen debranching enzyme (GDE) in liver and muscle. The disorder is clinically heterogeneous and progressive, and there is no effective treatment. Previously, a naturally occurring dog model for this condition was identified in curly-coated retrievers (CCR). The affected dogs carry a frame-shift mutation in the GDE gene and have no detectable GDE activity in liver and muscle. We ...

  6. Evaluation of Yield, Dry Matter Accumulation and Leaf Area Index in Wheat Genotypes as Affected by Terminal Drought Stress

    Directory of Open Access Journals (Sweden)

    Mortaza Sam DALIRIE

    2010-06-01

    Full Text Available Grain yield of wheat (Triticum aestivum L. under Mediterranean conditions is frequently limited by both high temperature and drought during grain growth. In this region, most rain falls during autumn and winter and water deficit emerges in the spring, resulting in a moderate stress for rainfed wheat around anthesis, which increases in severity throughout grain filling. Hence, selection of genotypes with high grain yield is the principal aim of wheat production in this region. In order to evaluation of yield and dry matter accumulation in wheat genotypes as affected by terminal drought stress, a factorial experiment based on randomized complete block design was conducted in Research Farm Islamic Azad University, Ardabil branch in 2009. Factors were: terminal drought stress by changing in planting date at three levels (12 October, 1 November and 21 November with wheat (Triticu aestivum L. genotypes at four levels (�Azar-2�, �Sardari�, �Frankia� and �Trakia�. The results showed that various levels of terminal drought stress affected yield, dry matter accumulation and leaf area index in wheat genotypes. Means comparisons showed that maximum grain yield (183.18 gr/m2 was obtained at the first of planting date or the least duration of confronting with thermal drought stress in �Azar-2� genotype and minimum of it was obtained in the third planting date with �Trakia� genotype due to the highest duration of confronting with thermal drought stress. Investigation of variances trend of dry matter accumulation indicated that in all of treatment compounds, it increased slowly until 190-200 days after sowing and then increased rapidly till 270-280 days after sowing. From 280 days after sowing till harvest time, it decreased due to increasing aging of leaves and decreasing of leaf area index. In the other hand, wheat genotypes had difference response to dry matter accumulation in confronting with thermal drought stress. Decrease in

  7. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil.

    Science.gov (United States)

    Holmstrup, Martin; Sørensen, Jesper G; Overgaard, Johannes; Bayley, Mark; Bindesbøl, Anne-Mette; Slotsbo, Stine; Fisker, Karina V; Maraldo, Kristine; Waagner, Dorthe; Labouriau, Rodrigo; Asmund, Gert

    2011-01-01

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. PMID:20870326

  8. Effect of endurance exercise training on muscle glycogen supercompensation in rats.

    Science.gov (United States)

    Nakatani, A; Han, D H; Hansen, P A; Nolte, L A; Host, H H; Hickner, R C; Holloszy, J O

    1997-02-01

    The purpose of this study was to test the hypothesis that the rate and extent of glycogen supercompensation in skeletal muscle are increased by endurance exercise training. Rats were trained by using a 5-wk-long swimming program in which the duration of swimming was gradually increased to 6 h/day over 3 wk and then maintained at 6 h/day for an additional 2 wk. Glycogen repletion was measured in trained and untrained rats after a glycogen-depleting bout of exercise. The rats were given a rodent chow diet plus 5% sucrose in their drinking water and libitum during the recovery period. There were remarkable differences in both the rates of glycogen accumulation and the glycogen concentrations attained in the two groups. The concentration of glycogen in epitrochlearis muscle averaged 13.1 +/- 0.9 mg/g wet wt in the untrained group and 31.7 +/- 2.7 mg/g in the trained group (P supercompensation in rats. PMID:9049757

  9. Histochemical Effects of “Verita WG” on Glycogen and Lipid Storage in Common Carp (Cyprinus carpio L. Liver

    Directory of Open Access Journals (Sweden)

    Elenka Georgieva

    2013-12-01

    Full Text Available We aimed in the present work is to study the effects of fosetyl-Al and fenamidone based fungicide (“Verita WG” on glycogen storage and expression of lipid droplets in common carp (Cyprinus carpio, L. liver. Concentrations of the test chemical were 30 mg/L, 38 mg/L and 50 mg/L under laboratory conditions. We used PAS-reaction for detection of glycogen storage and Sudan III staining for detection of lipid droplets in common carp hepatocytes. Hence, we found that the amount of glycogen and the fat storage in the liver increased proportionally with the increased fungicide concentrations. We also found conglomerates of accumulated glycogen in certain hepatocytes at all used concentrations. Overall, the results demonstrated enhanced glyconeogenesis and fat accumulation in the common carp liver, exposed to the test chemical.

  10. Coordinate genetic regulation of glycogen catabolism and biosynthesis in Escherichia coli via the CsrA gene product.

    OpenAIRE

    Yang, H.; Liu, M Y; Romeo, T

    1996-01-01

    The carbon storage regulator gene, csrA, encodes a factor which negatively modulates the expression of the glycogen biosynthetic gene glgC by enhancing the decay of its mRNA (M. Y. Liu, H. Yang, and T. Romeo, J. Bacteriol. 177:2663-2672, 1995). When endogenous glycogen levels in isogenic csrA+ and csrA::kanR strains were quantified during the growth curve, both the rate of glycogen accumulation during late exponential or early stationary phase and its subsequent rate of degradation were found...

  11. Threonine phosphorylation of rat liver glycogen synthase

    International Nuclear Information System (INIS)

    32P-labeled glycogen synthase specifically immunoprecipitated from 32P-phosphate incubated rat hepatocytes contains, in addition to [32P] phosphoserine, significant levels of [32P] phosphothreonine. When the 32P-immunoprecipitate was cleaved with CNBr, the [32P] phosphothreonine was recovered in the large CNBr fragment (CB-2, Mapp 28 Kd). Homogeneous rat liver glycogen synthase was phosphorylated by all the protein kinases able to phosphorylate CB-2 in vitro. After analysis of the immunoprecipitated enzyme for phosphoaminoacids, it was observed that only casein kinase II was able to phosphorylate on threonine and 32P-phosphate was only found in CB-2. These results demonstrate that rat liver glycogen synthase is phosphorylated at threonine site(s) contained in CB-2 and strongly indicate that casein kinase II may play a role in the ''in vivo'' phosphorylation of liver glycogen synthase. This is the first protein kinase reported to phosphorylate threonine residues in liver glycogen synthase

  12. Brain glycogen supercompensation following exhaustive exercise.

    Science.gov (United States)

    Matsui, Takashi; Ishikawa, Taro; Ito, Hitoshi; Okamoto, Masahiro; Inoue, Koshiro; Lee, Min-Chul; Fujikawa, Takahiko; Ichitani, Yukio; Kawanaka, Kentaro; Soya, Hideaki

    2012-02-01

    Brain glycogen localized in astrocytes, a critical energy source for neurons, decreases during prolonged exhaustive exercise with hypoglycaemia. However, it is uncertain whether exhaustive exercise induces glycogen supercompensation in the brain as in skeletal muscle. To explore this question, we exercised adult male rats to exhaustion at moderate intensity (20 m min(-1)) by treadmill, and quantified glycogen levels in several brain loci and skeletal muscles using a high-power (10 kW) microwave irradiation method as a gold standard. Skeletal muscle glycogen was depleted by 82-90% with exhaustive exercise, and supercompensated by 43-46% at 24 h after exercise. Brain glycogen levels decreased by 50-64% with exhaustive exercise, and supercompensated by 29-63% (whole brain 46%, cortex 60%, hippocampus 33%, hypothalamus 29%, cerebellum 63% and brainstem 49%) at 6 h after exercise. The brain glycogen supercompensation rates after exercise positively correlated with their decrease rates during exercise. We also observed that cortical and hippocampal glycogen supercompensation were sustained until 24 h after exercise (long-lasting supercompensation), and their basal glycogen levels increased with 4 weeks of exercise training (60 min day(-1) at 20 m min(-1)). These results support the hypothesis that, like the effect in skeletal muscles, glycogen supercompensation also occurs in the brain following exhaustive exercise, and the extent of supercompensation is dependent on that of glycogen decrease during exercise across brain regions. However, supercompensation in the brain preceded that of skeletal muscles. Further, the long-lasting supercompensation of the cortex and hippocampus is probably a prerequisite for their training adaptation (increased basal levels), probably to meet the increased energy demands of the brain in exercising animals. PMID:22063629

  13. High-Level Accumulation of Exogenous Small RNAs Not Affecting Endogenous Small RNA Biogenesis and Function in Plants

    Institute of Scientific and Technical Information of China (English)

    SHEN Wan-xia; Neil A Smith; ZHOU Chang-yong; WANG Ming-bo

    2014-01-01

    RNA silencing is a fundamental plant defence and gene control mechanism in plants that are directed by 20-24 nucleotide (nt) small interfering RNA (siRNA) and microRNA (miRNA). Infection of plants with viral pathogens or transformation of plants with RNA interference (RNAi) constructs is usually associated with high levels of exogenous siRNAs, but it is unclear if these siRNAs interfere with endogenous small RNA pathways and hence affect plant development. Here we provide evidence that viral satellite RNA (satRNA) infection does not affect siRNA and miRNA biogenesis or plant growth despite the extremely high level of satRNA-derived siRNAs. We generated transgenic Nicotiana benthamiana plants that no longer develop the speciifc yellowing symptoms generally associated with infection by Cucumber mosaic virus (CMV) Y-satellite RNA (Y-Sat). We then used these plants to show that CMV Y-Sat infection did not cause any visible phenotypic changes in comparison to uninfected plants, despite the presence of high-level Y-Sat siRNAs. Furthermore, we showed that the accumulation of hairpin RNA (hpRNA)-derived siRNAs or miRNAs, and the level of siRNA-directed transgene silencing, are not signiifcantly affected by CMV Y-Sat infection. Taken together, our results suggest that the high levels of exogenous siRNAs associated with viral infection or RNAi-inducing transgenes do not saturate the endogenous RNA silencing machineries and have no signiifcant impact on normal plant development.

  14. Identification of mutations in Type IV glycogen storage disease

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Y.; Kishnani, P.; Chen, Y.T. [Duke Univ. Medical Center, Durham, NC (United States)] [and others

    1994-09-01

    Type IV glycogen storage disease (GSD IV, Andersen disease) is caused by a deficiency of glycogen branching enzyme (GBE) activity, which results in the accumulation of glycogen with unbranched, long, outer chains in the tissues. The molecular basis of the disease is not known. We studied four patients with the disease; three with typical presentation of progressive liver cirrhosis and failure, and one with severe and fatal neonatal hypotonia and cardiomyopathy. Southern blot analysis with EcoRI or MspI did not detect gross DNA rearrangement, deletion or duplication in patients` glycogen branching enzyme genes. Northern analysis with total cellular RNAs isolated from skin fibroblast MI strains of three patients with typical clinical presentation showed a normal level and size (2.95 kb) of GBE mRNA hybridization band in two and absent mRNA hybridization band in the remaining one. The patient with atypical severe neonatal hypotonia demonstrated a less intense and smaller size (2.75 kb) of mRNA hybridization band. A 210 hp deletion from nucleotide sequence 873 to 1082 which causes 70 amino acids missing from amino acid sequence 262 to 331 was detected in all 17 clones sequenced from the fatal hypotonia patient. This deletion is located in the region which is highly conserved between prokaryotic, yeast and human GBE polypeptide sequences, and also includes the first of the four regions which constitute the catalytic active sites of most of amylolytic enzymes. A point mutation C-T (1633) which changes the amino acid from Arginine to Cystine was found in 19 of 20 cDNA clones from a patient with classical clinical presentation. This point mutation was unique to this patient and was not observed in three other patients or normal controls. This is the first report on the molecular basis of GSD IV and our data indicated the presence of extensive genetic heterogeneity in the disease.

  15. High glycogen levels enhance glycogen breakdown in isolated contracting skeletal muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Galbo, H

    1986-01-01

    after 15 min of intermittent electrical muscle stimulation. Before stimulation, glycogen was higher in rats that swam on the preceding day (supercompensated rats) compared with controls. During muscle contractions, glycogen breakdown in fast-twitch red and white fibers was larger in supercompensated......The influence of supranormal muscle glycogen levels on glycogen breakdown in contracting muscle was investigated. Rats either rested or swam for 3 h and subsequently had their isolated hindquarters perfused after 21 h with access to food. Muscle glycogen concentrations were measured before and...... hindquarters than in controls, and glycogenolysis correlated significantly with precontraction glycogen concentrations. In slow-twitch fibers, electrical stimulation did not elicit glycogenolysis in either group. Glucose uptake and lactate release were decreased and increased, respectively, in supercompensated...

  16. Constitutive expression of OsIAA9 affects starch granules accumulation and root gravitropic response in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Sha eLuo

    2015-12-01

    Full Text Available Auxin/Indole-3-Acetic Acid (Aux/IAA genes are early auxin response genes ecoding short-lived transcriptional repressors, which regulate auxin signaling in plants by interplay with Auxin Response Factors (ARFs. Most of the Aux/IAA proteins contain four different domains, namely Domain I, Domain II, Domain III and Domain IV. So far all Aux/IAA mutants with auxin-related phenotypes identified in both Arabidopsis and rice (Oryza sativa are dominant gain-of-function mutants with mutations in Domain II of the corresponding Aux/IAA proteins, suggest that Aux/IAA proteins in both Arabidopsis and rice are largely functional redundantly, and they may have conserved functions. We report here the functional characterization of a rice Aux/IAA gene, OsIAA9. RT-PCR results showed that expression of OsIAA9 was induced by exogenously applied auxin, suggesting that OsIAA9 is an auxin response gene. Bioinformatic analysis showed that OsIAA9 has a repressor motif in Domain I, a degron in Domain II, and the conserved amino acid signatures for protein-protein interactions in Domain III and Domain IV. By generating transgenic plants expressing GFP-OsIAA9 and examining florescence in the transgenic plants, we found that OsIAA9 is localized in the nucleus. When transfected into protoplasts isolated from rosette leaves of Arabidopsis, OsIAA9 repressed reporter gene expression, and the repression was partially released by exogenously IAA. These results suggest that OsIAA9 is a canonical Aux/IAA protein. Protoplast transfection assays showed that OsIAA9 interacted ARF5, but not ARF6, 7, 8 and 19. Transgenic Arabidopsis plants expressing OsIAA9 have increased number of lateral roots, and reduced gravitropic response. Further analysis showed that OsIAA9 transgenic Arabidopsis plants accumulated fewer granules in their root tips and the distribution of granules was also affected. Taken together, our study showed that OsIAA9 is a transcriptional repressor, and it regulates

  17. Effect of pH on Cleavage of Glycogen by Vaginal Enzymes.

    Science.gov (United States)

    Spear, Greg T; McKenna, Mary; Landay, Alan L; Makinde, Hadijat; Hamaker, Bruce; French, Audrey L; Lee, Byung-Hoo

    2015-01-01

    Glycogen expressed by the lower genital tract epithelium is believed to support Lactobacillus growth in vivo, although most genital isolates of Lactobacillus are not able to use glycogen as an energy source in vitro. We recently reported that α-amylase is present in the genital fluid of women and that it breaks down glycogen into small carbohydrates that support growth of lactobacilli. Since the pH of the lower genital tract can be very low, we determined how low pH affects glycogen processing by α-amylase. α-amylase in saliva degraded glycogen similarly at pH 6 and 7, but activity was reduced by 52% at pH 4. The glycogen degrading activity in nine genital samples from seven women showed a similar profile with an average reduction of more than 50% at pH 4. However, two samples collected from one woman at different times had a strikingly different pH profile with increased glycogen degradation at pH 4, 5 and 6 compared to pH 7. This second pH profile did not correlate with levels of human α-acid glucosidase or human intestinal maltase glucoamylase. High-performance anion-exchange chromatography showed that mostly maltose was produced from glycogen by samples with the second pH profile in contrast to genital α-amylase that yielded maltose, maltotriose and maltotetraose. These studies show that at low pH, α-amylase activity is reduced to low but detectable levels, which we speculate helps maintain Lactobacillus growth at a limited but sustained rate. Additionally, some women have a genital enzyme distinct from α-amylase with higher activity at low pH. Further studies are needed to determine the identity and distribution of this second enzyme, and whether its presence influences the makeup of genital microbiota. PMID:26171967

  18. Testicular Metabolic Reprogramming in Neonatal Streptozotocin-Induced Type 2 Diabetic Rats Impairs Glycolytic Flux and Promotes Glycogen Synthesis.

    Science.gov (United States)

    Rato, L; Alves, M G; Dias, T R; Cavaco, J E; Oliveira, Pedro F

    2015-01-01

    Defects in testicular metabolism are directly implicated with male infertility, but most of the mechanisms associated with type 2 diabetes- (T2DM) induced male infertility remain unknown. We aimed to evaluate the effects of T2DM on testicular glucose metabolism by using a neonatal-streptozotocin- (n-STZ) T2DM animal model. Plasma and testicular hormonal levels were evaluated using specific kits. mRNA and protein expression levels were assessed by real-time PCR and Western Blot, respectively. Testicular metabolic profile was assessed by (1)H-NMR spectroscopy. T2DM rats showed increased glycemic levels, impaired glucose tolerance and hyperinsulinemia. Both testicular and serum testosterone levels were decreased, whereas those of 17β-estradiol were not altered. Testicular glycolytic flux was not favored in testicles of T2DM rats, since, despite the increased expression of both glucose transporters 1 and 3 and the enzyme phosphofructokinase 1, lactate dehydrogenase activity was severely decreased contributing to lower testicular lactate content. However, T2DM enhanced testicular glycogen accumulation, by modulating the availability of the precursors for its synthesis. T2DM also affected the reproductive sperm parameters. Taken together these results indicate that T2DM is able to reprogram testicular metabolism by enhancing alternative metabolic pathways, particularly glycogen synthesis, and such alterations are associated with impaired sperm parameters. PMID:26064993

  19. Testicular Metabolic Reprogramming in Neonatal Streptozotocin-Induced Type 2 Diabetic Rats Impairs Glycolytic Flux and Promotes Glycogen Synthesis

    Directory of Open Access Journals (Sweden)

    L. Rato

    2015-01-01

    Full Text Available Defects in testicular metabolism are directly implicated with male infertility, but most of the mechanisms associated with type 2 diabetes- (T2DM induced male infertility remain unknown. We aimed to evaluate the effects of T2DM on testicular glucose metabolism by using a neonatal-streptozotocin- (n-STZ T2DM animal model. Plasma and testicular hormonal levels were evaluated using specific kits. mRNA and protein expression levels were assessed by real-time PCR and Western Blot, respectively. Testicular metabolic profile was assessed by 1H-NMR spectroscopy. T2DM rats showed increased glycemic levels, impaired glucose tolerance and hyperinsulinemia. Both testicular and serum testosterone levels were decreased, whereas those of 17β-estradiol were not altered. Testicular glycolytic flux was not favored in testicles of T2DM rats, since, despite the increased expression of both glucose transporters 1 and 3 and the enzyme phosphofructokinase 1, lactate dehydrogenase activity was severely decreased contributing to lower testicular lactate content. However, T2DM enhanced testicular glycogen accumulation, by modulating the availability of the precursors for its synthesis. T2DM also affected the reproductive sperm parameters. Taken together these results indicate that T2DM is able to reprogram testicular metabolism by enhancing alternative metabolic pathways, particularly glycogen synthesis, and such alterations are associated with impaired sperm parameters.

  20. The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio

    NARCIS (Netherlands)

    Martins, C.I.; Pristin, M.G.; Ende, S.S.W.; Eding, E.H.; Verreth, J.A.J.

    2009-01-01

    The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high

  1. The effect of high-intensity intermittent swimming on post-exercise glycogen supercompensation in rat skeletal muscle.

    Science.gov (United States)

    Sano, Akiko; Koshinaka, Keiichi; Abe, Natsuki; Morifuji, Masashi; Koga, Jinichiro; Kawasaki, Emi; Kawanaka, Kentaro

    2012-01-01

    A single bout of prolonged endurance exercise stimulates glucose transport in skeletal muscles, leading to post-exercise muscle glycogen supercompensation if sufficient carbohydrate is provided after the cessation of exercise. Although we recently found that short-term sprint interval exercise also stimulates muscle glucose transport, the effect of this type of exercise on glycogen supercompensation is uncertain. Therefore, we compared the extent of muscle glycogen accumulation in response to carbohydrate feeding following sprint interval exercise with that following endurance exercise. In this study, 16-h-fasted rats underwent a bout of high-intensity intermittent swimming (HIS) as a model of sprint interval exercise or low-intensity prolonged swimming (LIS) as a model of endurance exercise. During HIS, the rats swam for eight 20-s sessions while burdened with a weight equal to 18% of their body weight. The LIS rats swam with no load for 3 h. The exercised rats were then refed for 4, 8, 12, or 16 h. Glycogen levels were almost depleted in the epitrochlearis muscles of HIS- or LIS-exercised rats immediately after the cessation of exercise. A rapid increase in muscle glycogen levels occurred during 4 h of refeeding, and glycogen levels had peaked at the end of 8 h of refeeding in each group of exercised refed rats. The peak glycogen levels during refeeding were not different between HIS- and LIS-exercised refed rats. Furthermore, although a large accumulation of muscle glycogen in response to carbohydrate refeeding is known to be associated with decreased insulin responsiveness of glucose transport, and despite the fact that muscle glycogen supercompensation was observed in the muscles of our exercised rats at the end of 4 h of refeeding, insulin responsiveness was not decreased in the muscles of either HIS- or LIS-exercised refed rats compared with non-exercised fasted control rats at this time point. These results suggest that sprint interval exercise

  2. Changing nutrient stoichiometry affects phytoplankton production, DOP accumulation and dinitrogen fixation - a mesocosm experiment in the eastern tropical North Atlantic

    Science.gov (United States)

    Meyer, J.; Löscher, C. R.; Neulinger, S. C.; Reichel, A. F.; Loginova, A.; Borchard, C.; Schmitz, R. A.; Hauss, H.; Kiko, R.; Riebesell, U.

    2016-02-01

    Ocean deoxygenation due to climate change may alter redox-sensitive nutrient cycles in the marine environment. The productive eastern tropical North Atlantic (ETNA) upwelling region may be particularly affected when the relatively moderate oxygen minimum zone (OMZ) deoxygenates further and microbially driven nitrogen (N) loss processes are promoted. Consequently, water masses with a low nitrogen to phosphorus (N : P) ratio could reach the euphotic layer, possibly influencing primary production in those waters. Previous mesocosm studies in the oligotrophic Atlantic Ocean identified nitrate availability as a control of primary production, while a possible co-limitation of nitrate and phosphate could not be ruled out. To better understand the impact of changing N : P ratios on primary production and N2 fixation in the ETNA surface ocean, we conducted land-based mesocosm experiments with natural plankton communities and applied a broad range of N : P ratios (2.67-48). Silicic acid was supplied at 15 µmol L-1 in all mesocosms. We monitored nutrient drawdown, biomass accumulation and nitrogen fixation in response to variable nutrient stoichiometry. Our results confirmed nitrate to be the key factor determining primary production. We found that excess phosphate was channeled through particulate organic matter (POP) into the dissolved organic matter (DOP) pool. In mesocosms with low inorganic phosphate availability, DOP was utilized while N2 fixation increased, suggesting a link between those two processes. Interestingly this observation was most pronounced in mesocosms where nitrate was still available, indicating that bioavailable N does not necessarily suppress N2 fixation. We observed a shift from a mixed cyanobacteria-proteobacteria dominated active diazotrophic community towards a diatom-diazotrophic association of the Richelia-Rhizosolenia symbiosis. We hypothesize that a potential change in nutrient stoichiometry in the ETNA might lead to a general shift within

  3. [Glycogen storage disease by amylo 1,6-glucosidase deficiency (author's transl)].

    Science.gov (United States)

    Méndez Aparicio, F M

    1980-10-01

    A case of liver glycogen storage disease with amylo 1,6-glucosidase deficiency is reported. Enlarged liver was found at birth, and it is now accompanied by splenomegaly, low fasting blood glucose with ketonuria, elevation of transaminase values and glycogen accumulation with connective periportal tissue in liver histological study. In this glucogenosis results of functional tests on carbohidrate metabolism and glycogen enzymatic assay showed a direct relationship between functional and biochemical behaviour of liver cells. Amylo 1,6-glucosidase deficiency is accompanied by absence of glucogenolysis when glucagon is administrated after a long fast, and an increase of blood glucose when glucagon is administrated after food ingestion. Glycolisis tests show blood lactate elevation when some hexose or alanine are administrated; glyconeogenesis tests show blood glucose elevation when hexose, alanine or glycerol are administrated. PMID:6937153

  4. Dry matter and nitrogen accumulation are not affected by superoptimal concentration of ammonium in flowing solution culture with pH control

    Science.gov (United States)

    Rideout, J. W.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1994-01-01

    While it is known that superoptimal concentrations of the nitrate (NO3-) ion in solution culture do not increase NO3- uptake or dry matter accumulation, the same is not known for the ammonium (NH4+) ion. An experiment was conducted utilizing flowing solution culture with pH control to investigate the influence of superoptimal NH4+ concentrations on dry matter, nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) accumulation by nonnodulated soybean plants. Increasing the NH4+ concentration in solution from 1 to 10 mM did not affect dry matter or N accumulation. Accumulations of K, Ca, and Mg were slightly decreased with increased NH4+ concentration. The NH4+ uptake system, which is saturated at less than 1mM NH4+, is able to regulate uptake of NH4+ at concentrations as high as 10 mM.

  5. Accumulation of particulate matter and trace elements on vegetation as affected by pollution level, rainfall and the passage of time.

    Science.gov (United States)

    Przybysz, A; Sæbø, A; Hanslin, H M; Gawroński, S W

    2014-05-15

    Particulate matter is harmful to human health. To reduce its concentration in air, plants could be used as biological filters, accumulating particulate matter on their foliage. In a study carried out at three sites with differing pollution levels and exposure to precipitation, the capacity of evergreen species (Taxus baccata L., Hedera helix L. and Pinus sylvestris L.) to accumulate particulate matter and trace elements from ambient air in urban areas was investigated. The effects of rainfall and the passage of time on particulate matter deposition on foliage were also determined. The results showed that foliage accumulated an increasing quantity of particulate matter in successive months, but the actual amount of particulate matter and trace elements accumulated differed considerably between sites and plant species. The greatest accumulation of air pollutants occurred on the foliage of plants protected from the rain at a site exposed to traffic related pollution and the smallest accumulation at a rural site. Among the species analysed, the deposited mass of particulate matter and trace elements was the greatest on P. sylvestris. In all species, precipitation removed a considerable proportion of particles accumulated on foliage. Most of the removed particulate matter was large size fraction, but little belong to the smallest size fraction. These results showed that both, the dynamics of deposition and leaf washing by rain during the season need to be considered when evaluating the total effect of vegetation in pollutant remediation. PMID:24607629

  6. Hyper-accumulation of starch and oil in a Chlamydomonas mutant affected in a plant-specific DYRK kinase

    OpenAIRE

    Schulz-Raffelt, Miriam; Chochois, Vincent; Auroy, Pascaline; Cuiné, Stéphan; Billon, Emmanuelle; Dauvillée, David; Li-Beisson, Yonghua; Peltier, Gilles

    2016-01-01

    Background Because of their high biomass productivity and their ability to accumulate high levels of energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production of biofuel. Accumulation of reserve compounds takes place when microalgae face adverse situations such as nutrient shortage, conditions which also provoke a stop in cell division, and down-regulation of photosynthesis. Despite growing interest in microalgal biofuels, little is kn...

  7. Liver Glycogen Loading Dampens Glycogen Synthesis Seen in Response to Either Hyperinsulinemia or Intraportal Glucose Infusion

    Science.gov (United States)

    Winnick, Jason J.; An, Zhibo; Kraft, Guillaume; Ramnanan, Christopher J.; Irimia, Jose M.; Smith, Marta; Lautz, Margaret; Roach, Peter J.; Cherrington, Alan D.

    2013-01-01

    The purpose of this study was to determine the effect of liver glycogen loading on net hepatic glycogen synthesis during hyperinsulinemia or hepatic portal vein glucose infusion in vivo. Liver glycogen levels were supercompensated (SCGly) in two groups (using intraportal fructose infusion) but not in two others (Gly) during hyperglycemic-normoinsulinemia. Following a 2-h control period during which fructose infusion was stopped, there was a 2-h experimental period in which the response to hyperglycemia plus either 4× basal insulin (INS) or portal vein glucose infusion (PoG) was measured. Increased hepatic glycogen reduced the percent of glucose taken up by the liver that was deposited in glycogen (74 ± 3 vs. 53 ± 5% in Gly+INS and SCGly+INS, respectively, and 72 ± 3 vs. 50 ± 6% in Gly+PoG and SCGly+PoG, respectively). The reduction in liver glycogen synthesis in SCGly+INS was accompanied by a decrease in both insulin signaling and an increase in AMPK activation, whereas only the latter was observed in SCGly+PoG. These data indicate that liver glycogen loading impairs glycogen synthesis regardless of the signal used to stimulate it. PMID:22923473

  8. Regulation of glucose and glycogen metabolism during and after exercise.

    Science.gov (United States)

    Jensen, Thomas E; Richter, Erik A

    2012-03-01

    Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport is increased in the contracting muscle followed by a discussion of glycogen mobilization and synthesis by the action of glycogen phosphorylase and glycogen synthase, respectively. Finally, this review deals with the signalling relaying the well-described increased sensitivity of glucose transport to insulin in the post-exercise period which can result in an overshoot of intramuscular glycogen resynthesis post exercise (glycogen supercompensation). PMID:22199166

  9. Methodologies of tissue preservation and analysis of the glycogen content of the broiler chick liver.

    Science.gov (United States)

    Bennett, L W; Keirs, R W; Peebles, E D; Gerard, P D

    2007-12-01

    The current study was performed to develop convenient, rapid, reliable, and pragmatic methodologies by which to harvest and preserve liver tissue glycogen and to analyze its levels within reasonable limits of quantification and with extended chromophore stability. Absorbance values decreased by 2 h and again by 24 h after preparation of the iodine-potassium iodide chromophore, whereas absorbance values of the phenol-sulfuric acid chromophore remained constant over the same time period. These absorbance trends for each chromophore followed full color development within 5 min after combining the analyte with the respective chromophore reagent. Use of the phenol-sulfuric acid reagent allowed for a 10-fold reduction in assay limits of detection and quantification when compared with the iodine-potassium iodide reagent. Furthermore, glycogen concentration-absorbance relationships were affected by the source (i.e., rabbit liver vs. bovine liver) of glycogen standards when the iodine-potassium iodide chromophore was used, but the source of the standards had no influence when the phenol-sulfuric acid chromophore was used. The indifference of the phenol-sulfuric acid method to the glycogen source, as exhibited by similar linear regressions of absorbance, may be attributed to actual determination of glucose subunit concentrations after complete glycogen hydrolysis by sulfuric acid. This is in contrast to the actual measurement of whole glycogen, which may exhibit source- or time-related molecular structural differences. The iodine-potassium iodide methodology is a test of whole glycogen concentrations; therefore, it may be influenced by glycogen structural differences. Liver tissue sample weight (between 0.16 and 0.36 g) and processing, which included mincing, immediate freezing, or refrigeration in 10% perchloric acid for 1 wk prior to tissue grinding, had no effect on glycogen concentrations that were analyzed by using the phenol-sulfuric acid reagent. These results

  10. Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil

    International Nuclear Information System (INIS)

    Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time

  11. Genetics Home Reference: glycogen storage disease type VII

    Science.gov (United States)

    ... storage disease type VII glycogen storage disease type VII Enable Javascript to view the expand/collapse boxes. ... All Close All Description Glycogen storage disease type VII (GSDVII) is an inherited disorder caused by an ...

  12. Genetics Home Reference: glycogen storage disease type V

    Science.gov (United States)

    ... storage disease type V glycogen storage disease type V Enable Javascript to view the expand/collapse boxes. ... All Close All Description Glycogen storage disease type V (also known as GSDV or McArdle disease) is ...

  13. Genetics Home Reference: glycogen storage disease type I

    Science.gov (United States)

    ... storage disease type I glycogen storage disease type I Enable Javascript to view the expand/collapse boxes. ... All Close All Description Glycogen storage disease type I (also known as GSDI or von Gierke disease) ...

  14. Molecular cloning and seasonal expression of oyster glycogen phosphorylase and glycogen synthase genes

    OpenAIRE

    Bacca, Helene; Huvet, Arnaud; Fabioux, Caroline; Daniel, Jean-yves; Delaporte, Maryse; Pouvreau, Stephane; van Wormhoudt, A.; Moal, Jeanne

    2005-01-01

    To investigate the control at the mRNA level of glycogen metabolism in the cupped oyster Crassostrea gigas, we report in the present paper the cloning and characterization of glycogen phosphorylase and synthase cDNAs (Cg-GPH and Cg-GYS, respectively, transcripts of main enzymes for glycogen use and storage), and their first expression profiles depending on oyster tissues and seasons. A strong expression of both genes was observed in the labial palps and the gonad in accordance with specific c...

  15. Antifungal canthin-6-one series accumulate in lipid droplets and affect fatty acid metabolism in Saccharomyces cerevisiae

    OpenAIRE

    Lagoutte, D.; Nicolas, V; Poupon, E.; Fournet, Anne; Hocquemiller, R.; Libong, D.; Chaminade, P.; Loiseau, P.M.

    2008-01-01

    The mechanism of action of antifungal canthin-6-one series was investigated in Saccharomyces cerevisiae. After a rapid uptake, a preferential accumulation of the drug within lipid droplets was observed. The antifungal action of canthin-6-one was found as reversible. Canthin-6-one did not exhibit affinity for sterols, and membrane ergosterol was not necessary for the antifungal activity since the MICs were similar on an ergosterol-deleted and the wild-type S. cerevisiae clones. Relative amount...

  16. Properties of a glycogen like polysaccharide produced by a mutant of Escherichia coli lacking glycogen synthase and maltodextrin phosphorylase.

    Science.gov (United States)

    Kwak, Ji-Yun; Kim, Min-Gyu; Kim, Young-Wan; Ban, Hyun-Seung; Won, Mi-Sun; Park, Jong-Tae; Park, Kwan-Hwa

    2016-01-20

    Escherichia coli mutant TBP38 lacks glycogen synthase (GlgA) and maltodextrin phosphorylase (MalP). When grown on maltose in fed-batch fermentation TBP38 accumulated more than 50-fold higher glycogen-type polysaccharide than its parental strain. The polysaccharides were extracted at different growth stages and migrated as one peak in size-exclusion chromatography. TBP38 produced polysaccharides ranging 2.6 × 10(6)-4.6 × 10(6)Da. A ratio of short side-chains (DP ≦ 12) in the polysaccharides was greater than 50%, and number-average degree of polymerization varied from 9.8 to 8.4. The polysaccharides showed 70-290 times greater water-solubility than amylopectin. Km values using porcine and human pancreatic α-amylases with polysaccharides were 2- to 4-fold larger than that of amylopectin. kcat values were similar for both α-amylases. The TBP38 polysaccharides had 40-60% lower digestibility to amyloglucosidase than amylopectin. Intriguingly, the polysaccharides showed strong immunostimulating effects on mouse macrophage cell comparable to lipopolysaccharides. The lipopolysaccharide contamination levels were too low to account for this effect. PMID:26572397

  17. Glycogen Rich Clear Cell Breast Carcinoma: A Case Report

    OpenAIRE

    Çınkır, Havva Yeşil; Dilek, Gülay Bilir; Demirci, Ayşe; Başal, Fatma Buğdaycı; Aydın, Kübra; Demirci, Umut; Öksüzoğlu, Berna; Alkış, Necati

    2014-01-01

    Glycogen-rich clear cell carcinoma of the breast is a rare type of breast carcinoma. Tumoral tissue is consist of intracytoplasmic glycogen-rich clear cells. We presented in here a 44-year old woman diagnosed with glycogen-rich clear cell carcinoma.

  18. Regulation of glucose and glycogen metabolism during and after exercise

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Richter, Erik

    2012-01-01

    Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport i...... the post-exercise period which can result in an overshoot of intramuscular glycogen resynthesis post exercise (glycogen supercompensation)....

  19. Reciprocal expression of two candidate di-iron enzymes affecting photosystem I and light-harvesting complex accumulation.

    Science.gov (United States)

    Moseley, Jeffrey L; Page, M Dudley; Alder, Nancy P; Eriksson, Mats; Quinn, Jeanette; Soto, Feiris; Theg, Steven M; Hippler, Michael; Merchant, Sabeeha

    2002-03-01

    Crd1 (Copper response defect 1), which is required for the maintenance of photosystem I and its associated light-harvesting complexes in copper-deficient (-Cu) and oxygen-deficient (-O(2)) Chlamydomonas reinhardtii cells, is localized to the thylakoid membrane. A related protein, Cth1 (Copper target homolog 1), is shown to have a similar but not identical function by genetic suppressor analysis of gain-of-function sct1 (suppressor of copper target 1) strains that are transposon-containing alleles at CTH1. The pattern of Crd1 versus Cth1 accumulation is reciprocal; Crd1 abundance is increased in -Cu or -O(2) cells, whereas Cth1 accumulates in copper-sufficient (+Cu), oxygenated cells. This expression pattern is determined by a single trans-acting regulatory locus, CRR1 (COPPER RESPONSE REGULATOR 1), which activates transcription in -Cu cells. In +Cu cells, a 2.1-kb Cth1 mRNA is produced and translated, whereas Crd1 is transcribed only at basal levels, leading to Cth1 accumulation in +Cu cells. In -Cu cells, CRR1 function determines the activation of Crd1 expression and the production of an alternative 3.1-kb Cth1 mRNA that is extended at the 5' end relative to the 2.1-kb mRNA. Synthesis of the 3.1-kb mRNA, which encodes six small upstream open reading frames that possibly result in poor translation, blocks the downstream promoter through transcriptional occlusion. Fluorescence analysis of wild-type, crd1, and sct1 strains indicates that copper-responsive adjustment of the Cth1:Crd1 ratio results in modification of the interactions between photosystem I and associated light-harvesting complexes. The tightly coordinated CRR1-dependent regulation of isoenzymes Cth1 and Crd1 reinforces the notion that copper plays a specific role in the maintenance of chlorophyll proteins. PMID:11910013

  20. Light might regulate divergently depside and depsidone accumulation in the lichen Parmotrema hypotropum by affecting thallus temperature and water potential.

    Science.gov (United States)

    Armaleo, Daniele; Zhang, Yi; Cheung, Sonia

    2008-01-01

    Depsides and depsidones are the most common secondary products uniquely produced in lichens by the fungal symbiont, and they accumulate on the outer surface of its hyphae. Their biological roles are subject to debate. Quantitatively the compounds typical of a given lichen can vary dramatically from thallus to thallus. Several studies have addressed whether this variability is correlated with the light reaching different thalli, but the conclusions are contradictory. We addressed the question with the lichen Parmotrema hypotropum growing on unshaded, vertical tree trunks, a controlled natural environment where the light absorbed by each thallus over its lifetime is the only major position-dependent variable. The exact north-east-south-west orientation of each thallus was used to calculate its yearly light exposure based on astronomical and meteorological considerations. The calculated irradiation around the trunk, distributed over a continuous 40-fold intensity range, then was compared with the amount of compound per unit thallus weight, determined by quantitative thin layer chromatography. P. hypotropum accumulates the depside atranorin in the cortex and the depsidone norstictic acid in the medulla and around the algae. A direct correlation was observed between the yearly amount of light reaching the lichen and the amount of atranorin. In contrast, the amount of norstictic acid decreased with increasing light. Although we did not measure thallus temperature and water potential, a unifying interpretation of these and other published data is that depside/depsidone accumulation in lichens is mediated by localized changes in temperature and water potential produced by light absorption within each thallus. This suggests water relations-based functions for depsides and depsidones. PMID:18833750

  1. Hepatic glycogen deposition in a patient with anorexia nervosa and persistently abnormal transaminase levels.

    Science.gov (United States)

    Kransdorf, Lisa N; Millstine, Denise; Smith, Maxwell L; Aqel, Bashar A

    2016-04-01

    Anorexia nervosa and other eating disorders characterized by calorie restriction have been associated with a variety of hepatic abnormalities. Fatty steatosis has been described in eating disorder patients. We report the rare finding of glycogen accumulation in the liver in a patient with anorexia nervosa, which to our knowledge is only the second such case reported in the literature. This case highlights the importance of monitoring for liver abnormalities in patients with restrictive eating disorders. PMID:26066296

  2. Abnormal Metabolism of Glycogen Phosphate as a Cause for Lafora Disease*

    OpenAIRE

    Tagliabracci, Vincent S; Girard, Jean Marie; Segvich, Dyann; Meyer, Catalina; Turnbull, Julie; Zhao, Xiaochu; Minassian, Berge A; DePaoli-Roach, Anna A.; Peter J Roach

    2008-01-01

    Lafora disease is a progressive myoclonus epilepsy with onset in the teenage years followed by neurodegeneration and death within 10 years. A characteristic is the widespread formation of poorly branched, insoluble glycogen-like polymers (polyglucosan) known as Lafora bodies, which accumulate in neurons, muscle, liver, and other tissues. Approximately half of the cases of Lafora disease result from mutations in the EPM2A gene, which encodes laforin, a member of the dua...

  3. Glycogen metabolism in aerobic mixed cultures

    DEFF Research Database (Denmark)

    Dircks, Klaus; Beun, J.J.; van Loosdrecht, M.C.M.;

    2001-01-01

    In this study, the metabolism of glycogen storage and consumption in mixed cultures under aerobic conditions is described. The experimental results are used to calibrate a metabolic model, which as sole stoichiometric variables has the efficiency of oxidative phosphorylation (delta) and maintenan...

  4. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Holmstrup, Martin, E-mail: martin.holmstrup@dmu.d [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Sorensen, Jesper G. [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Overgaard, Johannes; Bayley, Mark [Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Bindesbol, Anne-Mette [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Slotsbo, Stine; Fisker, Karina V.; Maraldo, Kristine [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Waagner, Dorthe [National Environmental Research Institute, Aarhus University, Department of Terrestrial Ecology, Vejlsovej 25, DK-8600 Silkeborg (Denmark); Zoophysiology, Department of Biological Sciences, Aarhus University, Building 131, DK-8000 Aarhus C (Denmark); Labouriau, Rodrigo [Aarhus University, Faculty of Agricultural Sciences, Department of Genetics and Biotechnology, Research Centre Foulum, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Asmund, Gert [National Environmental Research Institute, Aarhus University, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2011-01-15

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. - Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation of aluminium and nickel has energetic costs.

  5. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    International Nuclear Information System (INIS)

    Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel and zinc appeared to be regulated and kept at low internal concentrations compared to soil concentrations. Lead, cadmium and copper accumulation did not correlate with glycogen reserves of individual worms. In contrast, aluminium, nickel and zinc were negatively correlated with glycogen reserves. These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. - Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation of aluminium and nickel has energetic costs.

  6. Contributions of Glycogen to Astrocytic Energetics during Brain Activation

    OpenAIRE

    Dienel, Gerald A.; Nancy F Cruz

    2014-01-01

    Glycogen is the major store of glucose in brain and is mainly in astrocytes. Brain glycogen levels in unstimulated, carefully-handled rats are 10-12 mol/g, and assuming that astrocytes account for half the brain mass, astrocytic glycogen content is twice as high. Glycogen turnover is slow under basal conditions, but it is mobilized during activation. There is no net increase in incorporation of label from glucose during activation, whereas label release from pre-labeled glycogen exceeds net g...

  7. Glycogen metabolism in rat heart muscle cultures after hypoxia.

    Science.gov (United States)

    Vigoda, Ayelet; Mamedova, Liaman K; Shneyvays, Vladimir; Katz, Abram; Shainberg, Asher

    2003-12-01

    Elevated glycogen levels in heart have been shown to have cardioprotective effects against ischemic injury. We have therefore established a model for elevating glycogen content in primary rat cardiac cells grown in culture and examined potential mechanisms for the elevation (glycogen supercompensation). Glycogen was depleted by exposing the cells to hypoxia for 2 h in the absence of glucose in the medium. This was followed by incubating the cells with 28 mM glucose in normoxia for up to 120 h. Hypoxia decreased glycogen content to about 15% of control, oxygenated cells. This was followed by a continuous increase in glycogen in the hypoxia treated cells during the 120 h recovery period in normoxia. By 48 h after termination of hypoxia, the glycogen content had returned to baseline levels and by 120 h glycogen was about 150% of control. The increase in glycogen at 120 h was associated with comparable relative increases in glucose uptake (approximately 180% of control) and the protein level of the glut-1 transporter (approximately 170% of control), whereas the protein level of the glut-4 transporter was decreased to supercompensation in cultures of cardiac cells that is explained by concerted increases in glucose uptake and glycogen synthase activity and decreases in phosphorylase activity. This model should prove useful in studying the cardioprotective effects of glycogen. PMID:14674711

  8. Climate, Soil Management, and Cultivar Affect Fusarium Head Blight Incidence and Deoxynivalenol Accumulation in Durum Wheat of Southern Italy

    Science.gov (United States)

    Scala, Valeria; Aureli, Gabriella; Cesarano, Gaspare; Incerti, Guido; Fanelli, Corrado; Scala, Felice; Reverberi, Massimo; Bonanomi, Giuliano

    2016-01-01

    Fusarium head blight (FHB) is a multifaceted disease caused by some species of Fusarium spp. A huge production of mycotoxins, mostly trichothecenes, often accompanied this disease. Amongst these toxic compounds, deoxynivalenol (DON) and its derivatives represent a major issue for human as well as for animal health and farming. Common and durum wheat are amongst the hosts of trichothecene-producing Fusaria. Differences in susceptibility to fungal infection and toxin accumulation occur in wheat cultivars. Recently, increasing incidence and severity of Fusarium infection and a higher DON accumulation in durum wheat were observed in Italy, especially in Northern regions. In this study, we analyzed wheat yield, technological parameters, the incidence of Fusarium infection and DON content in kernel samples of durum wheat coming from three locations of Southern Italy with different climatic conditions and grown during two seasons, with two methods of cultivation. Four different durum wheat cultivars prevalently cultivated in Southern Italian areas were chosen for this study. Our analysis showed the effects of environment and cultivar types on wheat productivity and key technological parameters for the quality level of the end-product, namely pasta. Notably, although a low rate of mycotoxin contamination in all study sites was assessed, an inverse relation emerged between fungal infection/DON production and durum wheat yield. Further, our study pinpoints the importance of environment conditions on several quality traits of durum wheat grown under Mediterranean climate. The environmental conditions at local level (microscale) and soil management practices may drive FHB outbreak and mycotoxin contamination even in growing area suitable for cropping this wheat species. PMID:27446052

  9. Climate, Soil Management, and Cultivar Affect Fusarium Head Blight Incidence and Deoxynivalenol Accumulation in Durum Wheat of Southern Italy.

    Science.gov (United States)

    Scala, Valeria; Aureli, Gabriella; Cesarano, Gaspare; Incerti, Guido; Fanelli, Corrado; Scala, Felice; Reverberi, Massimo; Bonanomi, Giuliano

    2016-01-01

    Fusarium head blight (FHB) is a multifaceted disease caused by some species of Fusarium spp. A huge production of mycotoxins, mostly trichothecenes, often accompanied this disease. Amongst these toxic compounds, deoxynivalenol (DON) and its derivatives represent a major issue for human as well as for animal health and farming. Common and durum wheat are amongst the hosts of trichothecene-producing Fusaria. Differences in susceptibility to fungal infection and toxin accumulation occur in wheat cultivars. Recently, increasing incidence and severity of Fusarium infection and a higher DON accumulation in durum wheat were observed in Italy, especially in Northern regions. In this study, we analyzed wheat yield, technological parameters, the incidence of Fusarium infection and DON content in kernel samples of durum wheat coming from three locations of Southern Italy with different climatic conditions and grown during two seasons, with two methods of cultivation. Four different durum wheat cultivars prevalently cultivated in Southern Italian areas were chosen for this study. Our analysis showed the effects of environment and cultivar types on wheat productivity and key technological parameters for the quality level of the end-product, namely pasta. Notably, although a low rate of mycotoxin contamination in all study sites was assessed, an inverse relation emerged between fungal infection/DON production and durum wheat yield. Further, our study pinpoints the importance of environment conditions on several quality traits of durum wheat grown under Mediterranean climate. The environmental conditions at local level (microscale) and soil management practices may drive FHB outbreak and mycotoxin contamination even in growing area suitable for cropping this wheat species. PMID:27446052

  10. Functional significance of brain glycogen in sustaining glutamatergic neurotransmission

    DEFF Research Database (Denmark)

    Sickmann, Helle M; Walls, Anne B; Schousboe, Arne;

    2009-01-01

    The involvement of brain glycogen in sustaining neuronal activity has previously been demonstrated. However, to what extent energy derived from glycogen is consumed by astrocytes themselves or is transferred to the neurons in the form of lactate for oxidative metabolism to proceed is at present...... for the astrocytic compartment. By inhibiting glycogen degradation in co-cultures it was evident that glycogen provides energy to sustain glutamatergic neurotransmission, i.e. release and uptake of glutamate. The relocation of glycogen derived lactate to the neuronal compartment was investigated by...... unclear. The significance of glycogen in fueling glutamate uptake into astrocytes was specifically addressed in cultured astrocytes. Moreover, the objective was to elucidate whether glycogen derived energy is important for maintaining glutamatergic neurotransmission, induced by repetitive exposure to NMDA...

  11. Changing nutrient stoichiometry affects phytoplankton production, DOP accumulation and dinitrogen fixation - A mesocosm experiment in the eastern tropical North Atlantic

    DEFF Research Database (Denmark)

    Meyer, J.; Löscher, C. R.; Neulinger, S. C.;

    2016-01-01

    Ocean deoxygenation due to climate change may alter redox-sensitive nutrient cycles in the marine environment. The productive eastern tropical North Atlantic (ETNA) upwelling region may be particularly affected when the relatively moderate oxygen minimum zone (OMZ) deoxygenates further and...

  12. Ordered synthesis and mobilization of glycogen in the perfused heart

    International Nuclear Information System (INIS)

    The molecular order of synthesis and mobilization of glycogen in the perfused heart was studied by 13C NMR. By varying the glucose isotopomer ([1-13C]glucose or [2-13C]glucose) supplied to the heart, glycogen synthesized at different times during the perfusion was labeled at different carbon sites. Subsequently, the in situ mobilization of glycogen during ischemia was observed by detection of labeled lactate derived from glycolysis of the glucosyl monomers. When [1-13C]glucose was given initially in the perfusion and [2-13C]glucose was given second, [2-13C]lactate was detected first during ischemia and [3-13C]lactate second. This result, and the equivalent result when the glucose labels were given in the reverse order, demonstrates that glycogen synthesis and mobilization are ordered in the heart, where glycogen is found morphologically only as β particles. Previous studies of glycogen synthesis and mobilization in liver and adipocytes have suggested that the organization of β particles into α particles was partially responsible for ordered synthesis and mobilization. The observations reported here for cardiac glycogen suggest that another mechanism is responsible. In addition to examine the ordered synthesis and mobilization of cardiac glycogen, the authors have selectively monitored the NMR properties of 13C-labeled glycogen synthesized early in the perfusion during further glycogen synthesis from a second, differently labeled substrate. During synthesis from the second labeled glucose monomer, the glycogen resonance from the first label decreased in integrated intensity and increased in line width. These results suggest either that there is significant isotopic exchange of glucosyl monomers in glycogen during net synthesis or that glucosyl residues incorporated into glycogen undergo motional restrictions as further glycogen synthesis occurs

  13. Temporal patterns of blood flow and nitric oxide synthase expression affect macrophage accumulation and proliferation during collateral growth

    Directory of Open Access Journals (Sweden)

    Sager Hendrik B

    2010-09-01

    Full Text Available Abstract Background The involvement of collateral blood flow/fluid shear stress, nitric oxide (NO, and macrophages during collateral growth (arteriogenesis is established, but their interplay remains paradoxical. Methods In order to further elucidate the "fluid shear stress/NO/macrophage" paradox, we investigated the time course of collateral blood flow (using a Doppler flow probe and NOS expression (immunohistochemistry, Western blot in growing rat collateral vessels after femoral artery occlusion and their impact on macrophage recruitment and collateral proliferation (immunohistochemistry, angiographies. Results (values are given as mean ± standard error of mean Early after occlusion, collateral blood flow was significantly reduced (pre- 90.0 ± 4.5 vs. post-occlusion 62.5 ± 5.9 μl/min; p p p p Conclusions We propose the following resolution of the "fluid shear stress/NO/macrophage" paradox: Collateral blood flow and NOS expression are initially reduced during arteriogenesis allowing macrophages to accumulate and therewith enhancing collateral proliferation. After homing of macrophages (24 h after occlusion, collateral blood flow and NOS expression recover in order to join the effects of macrophages for restoring blood flow.

  14. Mutational Inactivation of a Gene Homologous to Escherichia coli ptsP Affects Poly-β-Hydroxybutyrate Accumulation and Nitrogen Fixation in Azotobacter vinelandii

    OpenAIRE

    Segura, Daniel; Espín, Guadalupe

    1998-01-01

    Strain DS988, an Azotobacter vinelandii mutant with a reduced capacity to accumulate poly-β-hydroxybutyrate, was isolated after mini-Tn5 mutagenesis of the UW136 strain. Cloning and nucleotide sequencing of the affected locus revealed a gene homologous to Escherichia coli ptsP which encodes enzyme INtr, a homologue of enzyme I of the phosphoenol pyruvate-sugar phosphotransferase system with an N-terminal domain similar to the N-terminal domain of some NifA proteins. Strain DS988 was unable to...

  15. Structure-Function Analysis of PPP1R3D, a Protein Phosphatase 1 Targeting Subunit, Reveals a Binding Motif for 14-3-3 Proteins which Regulates its Glycogenic Properties.

    Directory of Open Access Journals (Sweden)

    Carla Rubio-Villena

    Full Text Available Protein phosphatase 1 (PP1 is one of the major protein phosphatases in eukaryotic cells. It plays a key role in regulating glycogen synthesis, by dephosphorylating crucial enzymes involved in glycogen homeostasis such as glycogen synthase (GS and glycogen phosphorylase (GP. To play this role, PP1 binds to specific glycogen targeting subunits that, on one hand recognize the substrates to be dephosphorylated and on the other hand recruit PP1 to glycogen particles. In this work we have analyzed the functionality of the different protein binding domains of one of these glycogen targeting subunits, namely PPP1R3D (R6 and studied how binding properties of different domains affect its glycogenic properties. We have found that the PP1 binding domain of R6 comprises a conserved RVXF motif (R102VRF located at the N-terminus of the protein. We have also identified a region located at the C-terminus of R6 (W267DNND that is involved in binding to the PP1 glycogenic substrates. Our results indicate that although binding to PP1 and glycogenic substrates are independent processes, impairment of any of them results in lack of glycogenic activity of R6. In addition, we have characterized a novel site of regulation in R6 that is involved in binding to 14-3-3 proteins (RARS74LP. We present evidence indicating that when binding of R6 to 14-3-3 proteins is prevented, R6 displays hyper-glycogenic activity although is rapidly degraded by the lysosomal pathway. These results define binding to 14-3-3 proteins as an additional pathway in the control of the glycogenic properties of R6.

  16. Fertilizer 15N Accumulation, Recovery and Distribution in Cotton Plant as Affected by N Rate and Split

    Institute of Scientific and Technical Information of China (English)

    YANG Guo-zheng; CHU Kun-yan; TANG Hao-yue; NIE Yi-chun; ZHANG Xian-long

    2013-01-01

    N fertilization of 300 kg N ha-1 is normally applied to cotton crops in three splits:pre-plant application (PPA, 30%), first bloom application (FBA, 40%) and peak bloom application (PBA, 30%) in the Yangtze River Valley China. However, low fertilizer N plant recovery (NPR) (30-35%) causes problems such as cotton yield stagnation even in higher N rate, low profit margin of cotton production and fertilizer release to the environment. Therefore, it is questioned:Are these three splits the same significance to cotton N uptake and distribution? An outdoor pot trial was conducted with five N rates and 15N labeled urea to determine the recovery and distribution of 15N from different splits in cotton (Gossypium hirsutum L. cv. Huazamian H318) plant. The results showed that, cotton plant absorbed fertilizer 15N during the whole growing period, the majority during flowering for 18-20 d regardless of N rates (150-600 kg ha-1). Fertilizer 15N proportion to the total N accumulated in cotton plant increased with N rates, and it was the highest in reproductive organs (88%averaged across N rates) among all the plant parts. FBA had the highest NPR (70%), the lowest fertilizer N lose (FNL, 19%), and the highest contribution to the fertilizer 15N proportion to the total N (46%) in cotton plant, whereas PPA had the reverse effect. It suggests that FBA should be the most important split for N absorption and yield formation comparatively and allocating more fertilizer N for late application from PPA should improve the benefit from fertilizer.

  17. The Competition between Polyphosphate-Accumulating Organisms and Glycogen-Accumulating Organisms: Temperature Effects and Modelling

    NARCIS (Netherlands)

    López Vázquez, C.M.

    2009-01-01

    Due to relatively high phosphorus removal efficiency and economy, the enhanced biological phosphorus removal (EBPR) in activated sludge wastewater treatment systems is a widely applied process to control and prevent eutrophication in surface water bodies. However, the EBPR process can be prone to su

  18. The competition between polyphosphate-accumulating organisms and glycogen-accumulating organisms: temperature effects and modelling

    NARCIS (Netherlands)

    López Vázquez, C.M.

    2009-01-01

    Due to relatively high phosphorus removal efficiency and economy, the enhanced biological phosphorus removal (EBPR) in activated sludge wastewater treatment systems is a widely applied process to control and prevent eutrophication in surface water bodies. However, the EBPR process can be prone to su

  19. Partial recovery of erythrocyte glycogen in diabetic rats treated with phenobarbital

    Directory of Open Access Journals (Sweden)

    da-Silva C.A.

    1997-01-01

    Full Text Available Erythrocytes may play a role in glucose homeostasis during the postprandial period. Erythrocytes from diabetic patients are defective in glucose transport and metabolism, functions that may affect glycogen storage. Phenobarbital, a hepatic enzyme inducer, has been used in the treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM, increasing the insulin-mediated glucose disposal. We studied the effects of phenobarbital treatment in vivo on glycemia and erythrocyte glycogen content in control and alloxan-diabetic rats during the postprandial period. In control rats (blood glucose, 73 to 111 mg/dl in femoral and suprahepatic veins the erythrocyte glycogen content was 45.4 ± 1.1 and 39.1 ± 0.8 µg/g Hb (mean ± SEM, N = 4-6 in the femoral artery and vein, respectively, and 37.9 ± 1.1 in the portal vein and 47.5 ± 0.9 in the suprahepatic vein. Diabetic rats (blood glucose, 300-350 mg/dl presented low (P<0.05 erythrocyte glycogen content, i.e., 9.6 ± 0.1 and 7.1 ± 0.7 µg/g Hb in the femoral artery and vein, respectively, and 10.0 ± 0.7 and 10.7 ± 0.5 in the portal and suprahepatic veins, respectively. After 10 days of treatment, phenobarbital (0.5 mg/ml in the drinking water did not change blood glucose or erythrocyte glycogen content in control rats. In diabetic rats, however, it lowered (P<0.05 blood glucose in the femoral artery (from 305 ± 18 to 204 ± 45 mg/dl and femoral vein (from 300 ± 11 to 174 ± 48 mg/dl and suprahepatic vein (from 350 ± 10 to 174 ± 42 mg/dl, but the reduction was not sufficient for complete recovery. Phenobarbital also stimulated the glycogen synthesis, leading to a partial recovery of glycogen stores in erythrocytes. In treated rats, erythrocyte glycogen content increased to 20.7 ± 3.8 µg/g Hb in the femoral artery and 30.9 ± 0.9 µg/g Hb in the suprahepatic vein (P<0.05. These data indicate that phenobarbital activated some of the insulin-stimulated glucose metabolism steps which were

  20. Excessive ammonia inhibited transcription of MsU2 gene and furthermore affected accumulation distribution of allantoin and amino acids in alfalfa Medicago sativa

    Institute of Scientific and Technical Information of China (English)

    WANG Li; JIANG Lin-lin; Nomura Mika; Tajima Shigeyuki; CHENG Xian-guo

    2015-01-01

    In legume plants, uricase gene (Nodulin-35) plays a positive role in metabolism of ureide and amide compounds in symbiotic nitrogen-ifxing in the nodules. In this study, a pot experiment was performed to examine the effects of ammonium application on the transcription of MsU2 gene and distribution of major nitrogen compounds in alfalfa Medicago sativa. Data showed that alfalfa plant has a signiifcant difference in contents of nitrogen compounds in xylem saps compared with soybean plant, and belongs to typical amide type legume plants with little ureide accumulation, and the accumulation of asparagines and ureide in the tissues of alfalfa is mainly gathered in the nodules. Northern blotting showed that excessive ammonium signiifcantly inhibited the transcription of MsU2 gene in the nodules and roots, and mRNA accumulation of MsU2 gene in the plants exposed to excessive ammonium decreased gradual y with culture time extension, indicating that application of ammonium signiifcantly inhibited the transcription of MsU2 gene in the alfalfa plants. Although the application of exces-sive ammonium increased the contents of amino acids in various tissues of alfalfa, the accumulation of al antoin relfecting the strength of uricase activity is remarkably reduced in the xylem saps, stems and nodules when alfalfa plants exposed to excessive ammonium, suggesting that application of excessive ammonium generated a negative effect on symbiosis ifxing-nitrogen system due to inhibition of ammonium ion on uricase activity in the nodules of alfalfa. This result seems to imply that application of excessive ammonium in legume plants should not be proposed to avoid affecting the ability of ifxing nitrogen in the nodules of legume plants, and reasonable dose of ammonium should be recommended to effectively utilize the ifxed N from atmosphere in legume plant production.

  1. Flavopiridol inhibits glycogen phosphorylase by binding at the inhibitor site.

    Science.gov (United States)

    Oikonomakos, N G; Schnier, J B; Zographos, S E; Skamnaki, V T; Tsitsanou, K E; Johnson, L N

    2000-11-01

    Flavopiridol (L86-8275) ((-)-cis-5, 7-dihydroxy-2-(2-chlorophenyl)-8-[4-(3-hydroxy-1-methyl)-piperidinyl] -4H-benzopyran-4-one), a potential antitumor drug, currently in phase II trials, has been shown to be an inhibitor of muscle glycogen phosphorylase (GP) and to cause glycogen accumulation in A549 non-small cell lung carcinoma cells (Kaiser, A., Nishi, K., Gorin, F.A., Walsh, D.A., Bradbury, E. M., and Schnier, J. B., unpublished data). Kinetic experiments reported here show that flavopiridol inhibits GPb with an IC(50) = 15.5 microm. The inhibition is synergistic with glucose resulting in a reduction of IC(50) for flavopiridol to 2.3 microm and mimics the inhibition of caffeine. In order to elucidate the structural basis of inhibition, we determined the structures of GPb complexed with flavopiridol, GPb complexed with caffeine, and GPa complexed with both glucose and flavopiridol at 1.76-, 2.30-, and 2.23-A resolution, and refined to crystallographic R values of 0.216 (R(free) = 0.247), 0.189 (R(free) = 0.219), and 0.195 (R(free) = 0.252), respectively. The structures provide a rational for flavopiridol potency and synergism with glucose inhibitory action. Flavopiridol binds at the allosteric inhibitor site, situated at the entrance to the catalytic site, the site where caffeine binds. Flavopiridol intercalates between the two aromatic rings of Phe(285) and Tyr(613). Both flavopiridol and glucose promote the less active T-state through localization of the closed position of the 280s loop which blocks access to the catalytic site, thereby explaining their synergistic inhibition. The mode of interactions of flavopiridol with GP is different from that of des-chloro-flavopiridol with CDK2, illustrating how different functional parts of the inhibitor can be used to provide specific and potent binding to two different enzymes. PMID:10924512

  2. Visceral adiposity influences glucose and glycogen metabolism in control and hyperlipidic-fed animals

    Directory of Open Access Journals (Sweden)

    Danielle Kaiser de Souza

    2013-04-01

    Full Text Available Introduction: Evidences suggest that fat intake, visceral obesity and intracellular lipids are related to insulin impairment. Objective: The objective of the present paper was correlate visceral obesity and metabolic alterations in control (CTR and hyperlipidic cafeteria diet (CFT fed animals. Methods: After 6 months of diet treatment, liver and muscle of the male rats were utilized to determined glucose uptake and glycogen metabolism after administration of 0.4I U/kg insulin in vivo, and correlate the visceral adiposity to these two parameters. Results: Ample range of physiologic answers to body composition in metabolic profile of the both diets was found. No differences were found in glycemia and triacylglycerol after insulin action in both groups, however CFT group accumulated higher adiposity, mostly visceral fat, and showed lower glycogen content in the liver. We also found an inverse correlation between visceral adiposity and glucose uptake and a decrease of the glycogen synthase active form in the liver. CTR animals demonstrated an inverse correlation between glucose uptake and visceral adiposity in the muscle. Discussion and conclusion: It was observed a variability of metabolic alterations in animals which can be related to degree of accumulation of abdominal adiposity and ingestion of diet fats. Further studies will be required to clarify the reasons for the observed liver alterations in CFT and muscle alterations in CTR animals.

  3. Muscle glycogen and cell function - Location, location, location

    DEFF Research Database (Denmark)

    Ørtenblad, N; Nielsen, Joachim

    2015-01-01

    The importance of glycogen, as a fuel during exercise, is a fundamental concept in exercise physiology. The use of electron microscopy has revealed that glycogen is not evenly distributed in skeletal muscle fibers, but rather localized in distinct pools. In this review, we present the available...... immobilization. Furthermore, these defined pools may serve specific functions in the cell. Specifically, reduced levels of these pools of glycogen are associated with reduced SR Ca(2+) release, muscle relaxation rate, and membrane excitability. Collectively, the available literature strongly demonstrates that...... the subcellular localization of glycogen has to be considered to fully understand the role of glycogen metabolism and signaling in skeletal muscle function. Here, we propose that the effect of low muscle glycogen on excitation-contraction coupling may serve as a built-in mechanism, which links the...

  4. The 3T3-L1 adipocyte glycogen proteome

    OpenAIRE

    Stapleton, David; Nelson, Chad; Parsawar, Krishna; Flores-Opazo, Marcelo; McClain, Donald; Parker, Glendon

    2013-01-01

    Background Glycogen is a branched polysaccharide of glucose residues, consisting of α-1-4 glycosidic linkages with α-1-6 branches that together form multi-layered particles ranging in size from 30 nm to 300 nm. Glycogen spatial conformation and intracellular organization are highly regulated processes. Glycogen particles interact with their metabolizing enzymes and are associated with a variety of proteins that intervene in its biology, controlling its structure, particle size and sub-cellula...

  5. Dysfunctional muscle and liver glycogen metabolism in mdx dystrophic mice.

    Directory of Open Access Journals (Sweden)

    David I Stapleton

    Full Text Available Duchenne muscular dystrophy (DMD is a severe, genetic muscle wasting disorder characterised by progressive muscle weakness. DMD is caused by mutations in the dystrophin (dmd gene resulting in very low levels or a complete absence of the dystrophin protein, a key structural element of muscle fibres which is responsible for the proper transmission of force. In the absence of dystrophin, muscle fibres become damaged easily during contraction resulting in their degeneration. DMD patients and mdx mice (an animal model of DMD exhibit altered metabolic disturbances that cannot be attributed to the loss of dystrophin directly. We tested the hypothesis that glycogen metabolism is defective in mdx dystrophic mice.Dystrophic mdx mice had increased skeletal muscle glycogen (79%, (P<0.01. Skeletal muscle glycogen synthesis is initiated by glycogenin, the expression of which was increased by 50% in mdx mice (P<0.0001. Glycogen synthase activity was 12% higher (P<0.05 but glycogen branching enzyme activity was 70% lower (P<0.01 in mdx compared with wild-type mice. The rate-limiting enzyme for glycogen breakdown, glycogen phosphorylase, had 62% lower activity (P<0.01 in mdx mice resulting from a 24% reduction in PKA activity (P<0.01. In mdx mice glycogen debranching enzyme expression was 50% higher (P<0.001 together with starch-binding domain protein 1 (219% higher; P<0.01. In addition, mdx mice were glucose intolerant (P<0.01 and had 30% less liver glycogen (P<0.05 compared with control mice. Subsequent analysis of the enzymes dysregulated in skeletal muscle glycogen metabolism in mdx mice identified reduced glycogenin protein expression (46% less; P<0.05 as a possible cause of this phenotype.We identified that mdx mice were glucose intolerant, and had increased skeletal muscle glycogen but reduced amounts of liver glycogen.

  6. High glycogen levels in the hippocampus of patients with epilepsy

    DEFF Research Database (Denmark)

    Dalsgaard, Mads K; Madsen, Flemming F; Secher, Niels H;

    2006-01-01

    During intense cerebral activation approximately half of the glucose plus lactate taken up by the human brain is not oxidized and could replenish glycogen deposits, but the human brain glycogen concentration is unknown. In patients with temporal lobe epilepsy, undergoing curative surgery, brain......, glycogen was similarly higher than in grey and white matter. Consequently, in human grey and white matter and, particularly, in the hippocampus of patients with temporal lope epilepsy, glycogen constitutes a large, active energy reserve, which may be of importance for energy provision during sustained...

  7. Intracellular compartmentalization of skeletal muscle glycogen metabolism and insulin signalling

    DEFF Research Database (Denmark)

    Prats Gavalda, Clara; Gomez-Cabello, Alba; Vigelsø Hansen, Andreas

    2011-01-01

    The interest in skeletal muscle metabolism and insulin signalling has increased exponentially in recent years as a consequence of their role in the development of type 2 diabetes mellitus. Despite this, the exact mechanisms involved in the regulation of skeletal muscle glycogen metabolism...... compartmentalization in the regulation of skeletal muscle glycogen metabolism and insulin signalling. As a result, a hypothetical regulatory mechanism is proposed by which cells could direct glycogen resynthesis towards different pools of glycogen particles depending on the metabolic needs. Furthermore, we discuss...... the role of skeletal muscle transverse tubules as potential modulators of tissue insulin responsiveness....

  8. Volume I. Glycogen: A historical overview, an adjunct to thesis. Volume II. Non-glucose components of glycogen

    International Nuclear Information System (INIS)

    Investigations have been carried out on three non-glucose components of native glycogen: protein, glucosamine, and phosphate. The protein, glycogenin, appears to serve as the primer upon which new molecules of glycogen are synthesized. When cell extracts are incubated with (14C)UDPG, (14C)glucose becomes transferred onto pre-existing chains of alpha-1,4 linked glucose associated with free glycogenin. The transferase and glycogenin remain associated during various purification steps. Liver glycogen appears to contain less than 0.02% protein which may correspond to the presence of one molecule of glycogenin (37 kDa) per alpha particle of liver glycogen. The core beta particle within each alpha particle may be synthesized upon glycogenin, while the remaining 20-40 beta particles may arise from each other. The author has demonstrated the natural occurrence of glucosamine in liver glycogen (but not muscle glycogen) from various species in an amount of about one molecule per molecule of glycogen. The glucosamine is underivatized, appears to be randomly scattered in the glycogen, and may be derived from dietary galactosamine. Similar to Fontana (1980), the author observed that native liver glycogen could be fractionated on DEAE-cellulose apparently on the basis of phosphate content. The more strongly bound glycogen possessed a greater molecular weight and content of glucosamine and phosphate. Possible explanations for these subfractions are considered. The phosphate appears to be concentrated near the center of the glycogen molecules. About 30% appears to be associated with glucose-6P and the remainder with an unidentified phosphodiester. The phosphate may stimulate glycogen synthesis. How the phosphate becomes incorporated is unknown

  9. Low Night Temperature Affects the Phloem Ultrastructure of Lateral Branches and Raffinose Family Oligosaccharide (RFO) Accumulation in RFO-Transporting Plant Melon (Cucumismelo L.) during Fruit Expansion.

    Science.gov (United States)

    Hao, Jinghong; Gu, Fengying; Zhu, Jie; Lu, Shaowei; Liu, Yifei; Li, Yunfei; Chen, Weizhi; Wang, Liping; Fan, Shuangxi; Xian, Cory J

    2016-01-01

    Due to the importance and complexity of photo assimilate transport in raffinose family oligosaccharide (RFO)-transporting plants such as melon, it is important to study the features of the transport structure (phloem) particularly of the lateral branches connecting the source leaves and the sink fruits, and its responses to environmental challenges. Currently, it is unclear to what extents the cold environmental temperature stress would alter the phloem ultrastructure and RFO accumulation in RFO-transporting plants. In this study, we firstly utilized electron microscopy to investigate the changes in the phloem ultrastructure of lateral branches and RFO accumulation in melons after being subjected to low night temperatures (12°C and 9°C). The results demonstrated that exposure to 9°C and 12°C altered the ultrastructure of the phloem, with the effect of 9°C being more obvious. The most obvious change was the appearance of plasma membrane invaginations in 99% companion cells and intermediary cells. In addition, phloem parenchyma cells contained chloroplasts with increased amounts of starch grains, sparse cytoplasm and reduced numbers of mitochondria. In the intermediary cells, the volume of cytoplasm was reduced by 50%, and the central vacuole was present. Moreover, the treatment at 9°C during the night led to RFO accumulation in the vascular bundles of the lateral branches and fruit carpopodiums. These ultrastructural changes of the transport structure (phloem) following the treatment at 9°C represented adaptive responses of melons to low temperature stresses. Future studies are required to examine whether these responses may affect phloem transport. PMID:27501301

  10. Expression of glycogen synthase (GYS) and glycogen synthase kinase 3β (GSK3β) of the Fujian oyster, Crassostrea angulata, in relation to glycogen content in gonad development.

    Science.gov (United States)

    Zeng, Zhen; Ni, Jianbin; Ke, Caihuan

    2013-01-01

    To investigate the regulation of glycogen metabolism at the mRNA level in Crassostrea angulata, we cloned and characterized glycogen synthase and glycogen synthase kinase 3β cDNAs (Ca-GYS and Ca-GSK3β, respectively), which encode the primary enzymes involved in glycogen storage. We examined their expression profiles in different tissues and during different reproductive stages. The full-length cDNA of GYS was 4771 bp in length with a 2023 bp open reading frame (ORF), predicted to encode a protein of 674 aa. The full-length GSK3β cDNA was 2333 bp long, with an ORF of 1242 bp. High expression levels of both genes were observed in the gonad and the adductor muscle, as compared to the mantle, gill, or visceral mass, which correlates well with the ability to store glucose. The regulation of both genes was correlated with glycogen content via qPCR and in situ hybridization and was dependent upon the stage of the reproductive cycle (initiation stage, maturation stage, ripeness stage). Thus, it appears that the expression of Ca-GYS and Ca-GSK3β is driven by the reproductive cycle of the oyster, reflecting the central role played by glycogen in energy storage and gametogenic development in C. angulata. We suggest that Ca-GYS and Ca-GSK3β can be used as useful molecular markers for identifying the stages of glycogen metabolism and reproduction in C. angulata. PMID:24035883

  11. Effects of Reduced Muscle Glycogen on Sarcoplasmic Reticulum (SR), Muscle and Exercise Performance

    OpenAIRE

    Batts, Timothy W.

    2002-01-01

    Fatigue during exercise is associated with reduced muscle glycogen. However, evidence linking glycogen content to fatigue is lacking. In this study we examined whether reduced muscle glycogen content limited SR function or muscle performance. Two groups of female Sprague-Dawley rats were fasted for 24 hr and exercised for 90 min to reduce muscle glycogen; rats fasted after exercise formed the low glycogen (LG) group. Rats in the high glycogen (HG) group were allowed free access to food and...

  12. Glycogen Storage Disease Type Ia in Canines: A Model for Human Metabolic and Genetic Liver Disease

    OpenAIRE

    Andrew Specht; Laurie Fiske; Kirsten Erger; Travis Cossette; John Verstegen; Martha Campbell-Thompson; Struck, Maggie B.; Young Mok Lee; Chou, Janice Y.; Byrne, Barry J; Correia, Catherine E.; Mah, Cathryn S.; Weinstein, David A.; Conlon, Thomas J.

    2011-01-01

    A canine model of Glycogen storage disease type Ia (GSDIa) is described. Affected dogs are homozygous for a previously described M121I mutation resulting in a deficiency of glucose-6-phosphatase-α. Metabolic, clinicopathologic, pathologic, and clinical manifestations of GSDIa observed in this model are described and compared to those observed in humans. The canine model shows more complete recapitulation of the clinical manifestations seen in humans including “lactic acidosis”, larger size,...

  13. Glycogen synthesis from lactate in a chronically active muscle

    International Nuclear Information System (INIS)

    In response to neural overactivity (pseudomyotonia), gastrocnemius muscle fibers from C57Bl/6Jdy2J/dy2J mice have different metabolic profiles compared with normal mice. A population of fibers in the fast-twitch superficial region of the dy2J gastrocnemius stores unusually high amounts of glycogen, leading to an increased glycogen storage in the whole muscle. The dy2J muscle also contains twice as much lactate as normal muscle. A [14C]lactate intraperitoneal injection leads to preferential 14C incorporation into glycogen in the dy2J muscle compared with normal muscle. To determine whether skeletal muscles were incorporating lactate into glycogen without body organ (liver, kidney) input, gastrocnemius muscles were bathed in 10 mM [14C]lactate with intact neural and arterial supply but with impeded venous return. The contralateral gastrocnemius serves as a control for body organ input. By using this in situ procedure, we demonstrate that under conditions of high lactate both normal and dy2J muscle can directly synthesize glycogen from lactate. In this case, normal whole muscle incorporates [14C] lactate into glycogen at a higher rate than dy2J whole muscle. Autoradiography, however, suggests that the high-glycogen-containing muscle fibers in the dy2J muscle incorporate lactate into glycogen at nearly four times the rate of normal or surrounding muscle fibers

  14. Mechanism of glycogen supercompensation in rat skeletal muscle cultures.

    Science.gov (United States)

    Mamedova, Liaman K; Shneyvays, Vladimir; Katz, Abram; Shainberg, Asher

    2003-08-01

    A model to study glycogen supercompensation (the significant increase in glycogen content above basal level) in primary rat skeletal muscle culture was established. Glycogen was completely depleted in differentiated myotubes by 2 h of electrical stimulation or exposure to hypoxia during incubation in medium devoid of glucose. Thereafter, cells were incubated in medium containing glucose, and glycogen supercompensation was clearly observed in treated myotubes after 72 h. Peak glycogen levels were obtained after 120 h, averaging 2.5 and 4 fold above control values in the stimulated- and hypoxia-treated cells, respectively. Glycogen synthase activity increased and phosphorylase activity decreased continuously during 120 h of recovery in the treated cells. Rates of 2-deoxyglucose uptake were significantly elevated in the treated cells at 96 and 120 h, averaging 1.4-2 fold above control values. Glycogenin content increased slightly in the treated cells after 48 h (1.2 fold vs. control) and then increased considerably, achieving peak values after 120 h (2 fold vs. control). The results demonstrate two phases of glycogen supercompensation: the first phase depends primarily on activation of glycogen synthase and inactivation of phosphorylase; the second phase includes increases in glucose uptake and glycogenin level. PMID:12962138

  15. Human skeletal muscle glycogen utilization in exhaustive exercise

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Holmberg, Hans-Christer; Schrøder, Henrik Daa;

    2011-01-01

    Although glycogen is known to be heterogeneously distributed within skeletal muscle cells, there is presently little information available about the role of fibre types, utilization and resynthesis during and after exercise with respect to glycogen localization. Here, we tested the hypothesis tha...

  16. RENAL COMPLICATIONS IN GLYCOGEN-STORAGE-DISEASE TYPE-I

    NARCIS (Netherlands)

    REITSMABIERENS, WCC

    1993-01-01

    Deficiency of the enzyme glucose-6-phosphatase is the biochemical defect in glycogen storage disease type I (GSD I). Normally this enzyme is present in the liver, intestine and kidneys. The lack of the enzyme in the kidney makes it obvious that glycogen storage will not be restricted to the liver bu

  17. The modulation of the symbiont/host interaction between Wolbachia pipientis and Aedes fluviatilis embryos by glycogen metabolism.

    Directory of Open Access Journals (Sweden)

    Mariana da Rocha Fernandes

    Full Text Available Wolbachia pipientis, a maternally transmitted bacterium that colonizes arthropods, may affect the general aspects of insect physiology, particularly reproduction. Wolbachia is a natural endosymbiont of Aedes fluviatilis, whose effects in embryogenesis and reproduction have not been addressed so far. In this context, we investigated the correlation between glucose metabolism and morphological alterations during A. fluviatilis embryo development in Wolbachia-positive (W+ and Wolbachia-negative (W- mosquito strains. While both strains do not display significant morphological and larval hatching differences, larger differences were observed in hexokinase activity and glycogen contents during early and mid-stages of embryogenesis, respectively. To investigate if glycogen would be required for parasite-host interaction, we reduced Glycogen Synthase Kinase-3 (GSK-3 levels in adult females and their eggs by RNAi. GSK-3 knock-down leads to embryonic lethality, lower levels of glycogen and total protein and Wolbachia reduction. Therefore, our results suggest that the relationship between A. fluviatilis and Wolbachia may be modulated by glycogen metabolism.

  18. Effects of insulin and glucagon on plasma glucose levels and glycogen content in organs of the freshwater teleost Pimelodus maculatus.

    Science.gov (United States)

    Carneiro, N M; Amaral, A D

    1983-01-01

    Mammalian insulin (350 IU/kg) and glucagon (2.5 mg/kg) were injected intraperitoneally into Pimelodus maculatus, a South American teleost. Extent of carbohydrate regulation was estimated through determination of plasma glucose levels, liver-somatic index, and liver and muscle glycogen contents. The effects of insulin administration, examined 6, 12, 24, 48, and 72 hr after injection, were manifested as a depletion of liver glycogen content after 12 hr and severe decrease in plasma glucose content after 24 hr; insulin had no effect on muscle glycogen or liver-somatic index. The effects of glucagon administration, examined 5, 15, 30, 90, and 360 min after injection, were a small increase in liver glycogen content after 15 min, and hyperglycemia, apparent after 30 min. Glucagon did not affect muscle glycogen or liver-somatic index. Control animals were injected intraperitoneally with saline solution. These results suggest that insulin and glucagon regulate the carbohydrate metabolism of P. maculatus by hormonal mechanisms similar to those operating in other teleost species and in mammals. PMID:6337926

  19. Obesity and type 2 diabetes in rats are associated with altered brain glycogen and amino-acid homeostasis

    DEFF Research Database (Denmark)

    Sickmann, Helle M; Waagepetersen, Helle S; Schousboe, Arne;

    2010-01-01

    Obesity and type 2 diabetes have reached epidemic proportions; however, scarce information about how these metabolic syndromes influence brain energy and neurotransmitter homeostasis exist. The objective of this study was to elucidate how brain glycogen and neurotransmitter homeostasis are affected...... by these conditions. [1-(13)C]glucose was administered to Zucker obese (ZO) and Zucker diabetic fatty (ZDF) rats. Sprague-Dawley (SprD), Zucker lean (ZL), and ZDF lean rats were used as controls. Several brain regions were analyzed for glycogen levels along with (13)C-labeling and content of....... The MCL ratios of glutamine and glutamate were decreased in the cerebellum of the ZO and the ZDF rats. Glycogen levels were also lower in this region. These results suggest that the obese and type 2 diabetic models were associated with lower brain glucose metabolism. Glucose metabolism through the TCA...

  20. Supercompensated glycogen loads persist 5 days in resting trained cyclists.

    Science.gov (United States)

    Arnall, David A; Nelson, Arnold G; Quigley, Jack; Lex, Stephen; Dehart, Tom; Fortune, Peggy

    2007-02-01

    Research data indicates a persistence of elevated muscle glycogen concentration 3 days post-supercompensation in resting athletes. This study expands our earlier findings by determining whether muscle glycogen remains elevated 3, 5, or 7 days post-supercompensation. Seventeen trained male cyclists underwent one bout of exhaustive exercise to deplete muscle glycogen. This was followed by a 3-day consumption of a high carbohydrate/low protein/low fat diet (85:08:07%). Three post-loading phases followed with subjects randomly assigned to either a 3-day, 5-day, or 7-day post-loading maintenance diet of 60% carbohydrate and limited physical activity. Biopsies (50-150 mg) of the vastus lateralis were obtained pre-load (BASELINE), at peak-load (PEAK), and either at 3-day, 5-day, or 7-day post-load (POST). On average, PEAK to POST muscle glycogen concentrations decreased 34, 20 and 46% respectively for the 3-, 5-, and 7-day POST groups. Only the 7-day post-load group's PEAK to POST mean muscle glycogen concentration decreased significantly. In addition, multi-regression analysis indicated that the PEAK glycogen level was the main determinant of the number of days that glycogen levels remained significantly greater than BASELINE. Thus, trained athletes' supercompensated glycogen levels can remain higher than normal for up to 5 days post-loading. The amount of carbohydrate consumed, the level of physical activity, and the magnitude of the glycogen supercompensation determine the interval for which the glycogen levels are elevated. PMID:17120016

  1. Leptosphaeria maculans effector AvrLm4-7 affects salicylic acid (SA) and ethylene (ET) signalling and hydrogen peroxide (H2 O2 ) accumulation in Brassica napus.

    Science.gov (United States)

    Nováková, Miroslava; Šašek, Vladimír; Trdá, Lucie; Krutinová, Hana; Mongin, Thomas; Valentová, Olga; Balesdent, Marie-HelEne; Rouxel, Thierry; Burketová, Lenka

    2016-08-01

    To achieve host colonization, successful pathogens need to overcome plant basal defences. For this, (hemi)biotrophic pathogens secrete effectors that interfere with a range of physiological processes of the host plant. AvrLm4-7 is one of the cloned effectors from the hemibiotrophic fungus Leptosphaeria maculans 'brassicaceae' infecting mainly oilseed rape (Brassica napus). Although its mode of action is still unknown, AvrLm4-7 is strongly involved in L. maculans virulence. Here, we investigated the effect of AvrLm4-7 on plant defence responses in a susceptible cultivar of B. napus. Using two isogenic L. maculans isolates differing in the presence of a functional AvrLm4-7 allele [absence ('a4a7') and presence ('A4A7') of the allele], the plant hormone concentrations, defence-related gene transcription and reactive oxygen species (ROS) accumulation were analysed in infected B. napus cotyledons. Various components of the plant immune system were affected. Infection with the 'A4A7' isolate caused suppression of salicylic acid- and ethylene-dependent signalling, the pathways regulating an effective defence against L. maculans infection. Furthermore, ROS accumulation was decreased in cotyledons infected with the 'A4A7' isolate. Treatment with an antioxidant agent, ascorbic acid, increased the aggressiveness of the 'a4a7' L. maculans isolate, but not that of the 'A4A7' isolate. Together, our results suggest that the increased aggressiveness of the 'A4A7' L. maculans isolate could be caused by defects in ROS-dependent defence and/or linked to suppressed SA and ET signalling. This is the first study to provide insights into the manipulation of B. napus defence responses by an effector of L. maculans. PMID:26575525

  2. The effect of substrate competition on the metabolism of polyphosphate accumulating organisms (PAOs).

    Science.gov (United States)

    Carvalheira, Mónica; Oehmen, Adrian; Carvalho, Gilda; Reis, Maria A M

    2014-11-01

    The type of carbon source present in the wastewater is one factor that affects the competition between polyphosphate accumulating organisms (PAO) and glycogen accumulating organisms (GAO) and therefore, the efficiency of the enhanced biological phosphorus removal (EBPR) process. This study investigated the impact of the carbon source composition on the anaerobic and aerobic kinetics of PAOs and the EBPR performance of an 85% PAO enrichment. When both acetate (HAc) and propionate (HPr) were present, propionate was depleted more quickly, with a constant uptake rate of 0.18 ± 0.02 C-mol/(C-mol biomass·h), while the acetate uptake rate decreased with an increase in propionate concentration, due to the substrate competition between acetate and propionate. The metabolic model for PAOs was modified to incorporate the anaerobic substrate competition effect. The aerobic rates for phosphorus (P) uptake, glycogen production and polyhydroxyalkanoates (PHA) degradation were within the same range for all tests, indicating that these rates are essentially independent of the acetate and propionate concentration, simplifying the calibration procedure for metabolic models. The metabolic model applied to describe the anaerobic and aerobic activity agreed well with the experimental data of HAc, HPr, P, PHA and biomass growth. The low glycogen consumption observed suggest that some reducing equivalents were generated anaerobically through the TCA cycle. The results of this work suggest that the propionate uptake kinetics by PAOs can provide them an advantage over GAOs in EBPR systems, even when the propionate fraction of the influent is relatively low. PMID:25051162

  3. ADP-Glucose Pyrophosphorylase, a Regulatory Enzyme for Bacterial Glycogen Synthesis

    OpenAIRE

    Ballicora, Miguel A; Iglesias, Alberto A.; Preiss, Jack

    2003-01-01

    The accumulation of α-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs by utilizing ADP-glucose as the glucosyl donor for elongation of the α-1,4-glucosidic chain. The main regulatory step takes place at the level of ADP-glucose synthesis, a reaction catalyzed by ADP-Glc pyrophosphorylase (PPase). Most of the ADP-Glc PPases are allosterically regulated by intermediates ...

  4. Glycogen metabolism and the homeostatic regulation of sleep

    KAUST Repository

    Petit, Jean-Marie

    2014-11-16

    In 1995 Benington and Heller formulated an energy hypothesis of sleep centered on a key role of glycogen. It was postulated that a major function of sleep is to replenish glycogen stores in the brain that have been depleted during wakefulness which is associated to an increased energy demand. Astrocytic glycogen depletion participates to an increase of extracellular adenosine release which influences sleep homeostasis. Here, we will review some evidence obtained by studies addressing the question of a key role played by glycogen metabolism in sleep regulation as proposed by this hypothesis or by an alternative hypothesis named “glycogenetic” hypothesis as well as the importance of the confounding effect of glucocorticoïds. Even though actual collected data argue in favor of a role of sleep in brain energy balance-homeostasis, they do not support a critical and direct involvement of glycogen metabolism on sleep regulation. For instance, glycogen levels during the sleep-wake cycle are driven by different physiological signals and therefore appear more as a marker-integrator of brain energy status than a direct regulator of sleep homeostasis. In support of this we provide evidence that blockade of glycogen mobilization does not induce more sleep episodes during the active period while locomotor activity is reduced. These observations do not invalidate the energy hypothesis of sleep but indicate that underlying cellular mechanisms are more complex than postulated by Benington and Heller.

  5. Heteropoly acid catalyzed hydrolysis of glycogen to glucose

    International Nuclear Information System (INIS)

    Complete conversion of glycogen to glucose is achieved by using H3PW12O40·nH2O (HPW) and H4SiW12O40·nH2O (HSiW) as catalysts for the hydrolysis under optimized hydrothermal conditions (mass fraction of catalyst 2.4%, 373 K and 2 h reaction time). The reusability of the catalyst (HPW) was demonstrated. In addition to carrying out the glycogen hydrolysis in an autoclave, other novel methods such as microwave irradiation and sonication have also been investigated. At higher mass fraction of the heteropoly acids (10.5%), glycogen could be completely converted to glucose under microwave irradiation. Sonication of an aqueous solution of glycogen in the presence of HPW and HSiW also yielded glucose. Thus, heteropoly acids are efficient, environmentally friendly and reusable catalysts for the conversion of glycogen to glucose. - Highlights: • Hydrothermal, microwave and sonication based methods of hydrolysis. • Heteropoly acids are green catalysts for glycogen hydrolysis. • Glycogen from cyanobacteria is demonstrated as a potential feedstock for glucose

  6. Glycogen repletion following continuous and intermittent exercise to exhaustion.

    Science.gov (United States)

    Gaesser, G A; Brooks, G A

    1980-10-01

    Patterns of postexercise glycogen repletion in heart, skeletal muscle, and liver in the absence of exogenously supplied substrates during the first 4 h of recovery were assessed. Female Wistar rats were run to exhaustion using continuous (1.0 mph, 15% grade) and intermittent (alternate 1-min intervals at 0.5 and 1.5 mph, 15% grade) exercise protocols. Rats at exhaustion were characterized by marked depletion of glycogen in heart (55%), skeletal muscle (94%), and liver (97%). Blood glucose levels at exhaustion (1.33 mumol/g) were only 37% of preexercise levels. There were no significant differences between continuous and intermittent exercise groups for any of the tissue glycogen or blood glucose values. Cardiac muscle was the only tissue capable of complete restoration of glycogen levels while relying exclusively upon endogenous substrates. Concentrations of endogenous substrates present at the end of exercise were insufficient to support restoration of blood glucose levels to preexercise values nor support glycogen repletion in skeletal muscle and liver during the initial 4-h food-restricted postexercise period. With subsequent feeding, skeletal muscle demonstrated a glycogen supercompensation effect at 24 h (181.1 and 191.8% of preexercise levels for continuous and intermittent exercise, respectively). Lactate concentration in all tissues at the point exhaustion (1.5--2.5 times resting levels) were only moderately elevated and returned to preexercise levels within 15 min. It was concluded that lactate removal after exercise contributed only minimally to the repletion of muscle glycogen. PMID:7440286

  7. Selection for low erucic acid and genetic mapping of loci affecting the accumulation of very long-chain fatty acids in meadowfoam seed storage lipids.

    Science.gov (United States)

    Gandhi, S D; Kishore, V K; Crane, J M; Slabaugh, M B; Knapp, S J

    2009-06-01

    Erucic acid (22:1(13)) has been identified as an anti-nutritional compound in meadowfoam (Limnanthes alba) and other oilseeds in the Brassicales, a classification which has necessitated the development of low erucic acid cultivars for human consumption. The erucic acid concentrations of meadowfoam wild types (8%-24%) surpass industry standards for human consumption (affecting the accumulation of 22:1(13) and other very long-chain fatty acids (VLCFAs) in meadowfoam seed storage lipids. LE76, a low erucic acid line, was developed by 3 cycles of selection in an ethyl methanesulfonate-treated wildtype population. LE76 produced 3% 22:1(13), threefold less than the M0 population. Wildtype x LE76 F2 populations produced continuous, approximately normal erucic and dienoic acid distributions. Loss-of-function mutations apparently did not segregate and individuals with low 22:1(13) concentrations (affecting VLCFA profiles in seed storage lipids by genotyping and phenotyping wildtype x low erucic acid F2 progeny. Composite interval mapping identified 3 moderately large-effect erucic acid QTL. The low erucic acid parent transmitted favorable alleles for 2 of 3 QTL, suggesting low erucic acid cultivars can be developed by combining favorable alleles transmitted by wildtype and low erucic acid parents. PMID:19483773

  8. Infantile Onset Glycogen Storage Disease Type 2: Case Report

    Directory of Open Access Journals (Sweden)

    Serkan Bilge Koca

    2014-08-01

    Full Text Available Glycogen storage disease type 2 (Pompe’s disease is an autosomal recessive, fatal glycogen storage disease presenting with hypotonia and muscle weakness. It is known that deficiency of lysosomal acid alpha-glucosidase (acid maltase leads to progressive generalised myopathy, cardiomyopathy and death in early infancy because of respiratory muscle weakness. Excessive undegradable intracellular glycogen deposition plays a role in the pathogenesis of the disease. Here we report a 3.5 month-old girl presenting with respiratory failure due to pneumonia and hypotonia, who was later diagnosed as Pompe disease.

  9. 一患青年型糖原贮积症Ⅱ型姐弟的家系GAA基因新突变分析%Analysis on novel mutations in GAA gene of a Chinese family with two siblings affected with juvenile onset form glycogen storage disease Ⅱ

    Institute of Scientific and Technical Information of China (English)

    徐玲玲; 唐雯; 梁玉坚; 张成; 黄雪琼; 张丽丹; 裴瑜馨; 程玉才

    2016-01-01

    目的:鉴定一患青年型糖原贮积症Ⅱ型(GSD Ⅱ)姐弟的家系酸性α‐葡萄糖苷酶(GAA )基因的新致病性突变。方法对因“反复呼吸道感染、呼吸衰竭伴全身肌无力”就诊的一姐弟俩的临床及家系资料进行分析,均经α‐1,4 GAA活性测定确诊为青年型GSD Ⅱ,并提取先证者及其父母的外周血脱氧核糖核酸(DNA),聚合酶链反应(PCR)扩增GAA基因的全部20个外显子及剪接位点序列,对PCR产物进行直接测序。结果弟弟GAA基因有2个复合杂合性突变,为遗传自父亲的外显子8的c .1216G>A(p .Asp406Asn)错义突变和遗传自母亲的外显子14的c .1935C> A(p .Asp645Glu)错义突变。结论 GAA基因的c .1216G>A和c .1935C>A复合杂合性突变导致了该患儿出现以呼吸困难及心肌肥厚为特征的青年型 GSD Ⅱ,新的突变c .1216G>A突变可能与青年型GSD Ⅱ相关。%Objective To identify a novel pathogenicity mutation of acid alpha‐glucosidase(GAA) gene in a Chinese family with two siblings affected with juvenile onset form glycogen storage disease Ⅱ(GSD Ⅱ) .Methods The clinical and family data of two siblings presenting recurrent respiratory tract infections ,respiratory failure associated with systemic muscle weakness ,were an‐alyzed and diagnosed with GSD Ⅱ by detecting alpha‐1 ,4‐glucosidase activity .DNA was extracted from peripheral blood of the proband ,younger brother and his parents .All 20 exons and the intron‐exon splice sites of GAA gene were amplified by polymerase chain reaction (PCR) .Mutations were detected by direct sequencing the PCR products .Results The younger brother was found to be compound heterozygous for two mutations in the GAA gene :c .1216G>A (p .Asp406Asn) missense mutation in the exon 8 from his father and c .1935C>A (p .Asp645Glu) missense mutation in the exon 14 from his mother .Conclusion The compound hetero‐zygous c .1216

  10. Accumulation and evolution of tocopherols in dry-cured hams from Iberian pigs as affected by their feeding and rearing system

    DEFF Research Database (Denmark)

    Rey, A I; Lopez-Bote, C J; Daza, A;

    2010-01-01

    The influence of feeding and rearing systems on the accumulation and evolution of α- and γ-tocopherols in relation to storage time in dry-cured ham slices and pieces was investigated. The accumulation of γ-tocopherol in Musculus Biceps femoris or fat of cured hams was lower in groups fed acorns i...

  11. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    Directory of Open Access Journals (Sweden)

    Terry J. Rose

    2016-01-01

    Full Text Available Enhanced efficiency nitrogen (N fertilizers (EEFs may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP and polymer-coated urea (PCU to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key mineral nutrients. Plant growth and mineral accumulation and partitioning to grains did not differ significantly between plants fertilized with urea or urea-DMPP. In contrast, biomass accumulation and the accumulation of phosphorus, potassium, calcium, magnesium, copper, zinc and manganese were delayed during the early growth phase of plants fertilized with PCU. However, plants in the PCU treatment ultimately compensated for this by increasing growth and nutrient uptake during the latter vegetative stages so that no differences in biomass or nutrient accumulation generally existed among N fertilizer treatments at anthesis. Delayed biomass accumulation in rice fertilized with PCU does not appear to reduce the total accumulation of mineral nutrients, nor to have any impact on grain mineral nutrition when biomass and grain yields are equal to those of rice grown with urea or urea-DMPP.

  12. The effect of glycogen depletion and supercompensation on the physical working capacity at the fatigue threshold.

    Science.gov (United States)

    Housh, T J; deVries, H A; Johnson, G O; Evans, S A; Tharp, G D; Housh, D J; Hughes, R J

    1990-01-01

    The purpose of this investigation was to determine the effect of glycogen depletion and supercompensation on the physical working capacity at the fatigue threshold (PWCFT). Ten adult males (mean age 23 years, SD 3) volunteered as subjects for this study. During the first laboratory visit the subjects performed a maximal bicycle ergometer test for the determination of maximum oxygen consumption (VO2max). Between 48 and 72 h later, the subjects pedaled to exhaustion at a power output which corresponded to a mean of 76% of VO2max (range, 72-80%) for the purpose of glycogen depletion. For the next 3 days, the subjects were fed a 10.5 MJ.day-1 low carbohydrate diet which consisted of 7.5% carbohydrates, 22.0% protein and 70.5% fat. The subjects then performed an incremental cycle ergometer test to the onset of fatigue or PWCFT, which was estimated from integrated electromyographic voltages of the vastus lateralis muscle. For the next 3 days the subjects were fed a 10.5 MJ high carbohydrate diet which consisted of 72.2% carbohydrates, 12.4% protein and 15.4% fats for the purpose of glycogen supercompensation. The subjects then performed a second PWCFT test. A paired t-test indicated that there was no significant (p greater than 0.05) difference between the means of the PWCFT values (depletion 246 W, SD 30; supercompensation 265 W, SD 28) and they were highly correlated at r = 0.884. The results of this investigation suggested that the methods commonly used to affect glycogen depletion or supercompensation had no effect on PWCFT. PMID:2369912

  13. Glycogen synthase kinase 3: more than a namesake

    OpenAIRE

    Rayasam, Geetha Vani; Tulasi, Vamshi Krishna; Sodhi, Reena; Davis, Joseph Alex; Ray, Abhijit

    2009-01-01

    Glycogen synthase kinase 3 (GSK3), a constitutively acting multi-functional serine threonine kinase is involved in diverse physiological pathways ranging from metabolism, cell cycle, gene expression, development and oncogenesis to neuroprotection. These diverse multiple functions attributed to GSK3 can be explained by variety of substrates like glycogen synthase, τ protein and β catenin that are phosphorylated leading to their inactivation. GSK3 has been implicated in various diseases such as...

  14. Clear cell mammary malignant myoepithelioma with abundant glycogens.

    OpenAIRE

    Kuwabara, H.; Uda, H

    1997-01-01

    Malignant myoepithelioma (myoepithelial carcinoma) of the breast is extremely rare. A case is reported of a 46 year old female with clear cell mammary malignant myoepithelioma that, on histological examination, was glycogen abundant clear cell carcinoma. Immunohistochemically, the clear cells showed myoepithelial differentiation--that is, they were a smooth muscle actin and S100 protein positive. This case shows that glycogen abundant clear cell carcinoma is a variant of malignant myoepitheli...

  15. Human Brain Glycogen Metabolism During and After Hypoglycemia

    Science.gov (United States)

    Öz, Gülin; Kumar, Anjali; Rao, Jyothi P.; Kodl, Christopher T.; Chow, Lisa; Eberly, Lynn E.; Seaquist, Elizabeth R.

    2009-01-01

    OBJECTIVE We tested the hypotheses that human brain glycogen is mobilized during hypoglycemia and its content increases above normal levels (“supercompensates”) after hypoglycemia. RESEARCH DESIGN AND METHODS We utilized in vivo 13C nuclear magnetic resonance spectroscopy in conjunction with intravenous infusions of [13C]glucose in healthy volunteers to measure brain glycogen metabolism during and after euglycemic and hypoglycemic clamps. RESULTS After an overnight intravenous infusion of 99% enriched [1-13C]glucose to prelabel glycogen, the rate of label wash-out from [1-13C]glycogen was higher (0.12 ± 0.05 vs. 0.03 ± 0.06 μmol · g−1 · h−1, means ± SD, P < 0.02, n = 5) during a 2-h hyperinsulinemic-hypoglycemic clamp (glucose concentration 57.2 ± 9.7 mg/dl) than during a hyperinsulinemic-euglycemic clamp (95.3 ± 3.3 mg/dl), indicating mobilization of glucose units from glycogen during moderate hypoglycemia. Five additional healthy volunteers received intravenous 25–50% enriched [1-13C]glucose over 22–54 h after undergoing hyperinsulinemic-euglycemic (glucose concentration 92.4 ± 2.3 mg/dl) and hyperinsulinemic-hypoglycemic (52.9 ± 4.8 mg/dl) clamps separated by at least 1 month. Levels of newly synthesized glycogen measured from 4 to 80 h were higher after hypoglycemia than after euglycemia (P ≤ 0.01 for each subject), indicating increased brain glycogen synthesis after moderate hypoglycemia. CONCLUSIONS These data indicate that brain glycogen supports energy metabolism when glucose supply from the blood is inadequate and that its levels rebound to levels higher than normal after a single episode of moderate hypoglycemia in humans. PMID:19502412

  16. Low birth weight and zygosity status is associated with defective muscle glycogen and glycogen synthase regulation in elderly twins

    DEFF Research Database (Denmark)

    Poulsen, Pernille; Wojtaszewski, Jørgen; Richter, Erik; Beck-Nielsen, Henning; Vaag, Allan

    2007-01-01

    lower fractional GS activity amidst higher glycogen and GS protein levels compared with dizygotic twins. In addition, we demonstrated strong nongenetic associations between birth weight and defect muscle glycogen metabolism in elderly--but not in younger--twins. Thus, for every 100 g increase in birth......OBJECTIVE: An adverse intrauterine environment indicated by both low birth weight and monozygosity is associated with an age- or time-dependent reduction in glucose disposal and nonoxidative glucose metabolism in twins, suggesting impaired regulation of muscle glycogen synthesis. RESEARCH DESIGN...... weight within pairs, GS fractional activity, GS protein level, and glycogen content was increased by 4.2, 8.7, and 4.5%, respectively, in elderly twins. Similarly, for every 100 g increase in birth weight, GSK3 alpha activity and GS phosphorylation at the sites 2, 2+2a, and 3a+3b were decreased by 3.1, 9...

  17. Body metal concentrations and glycogen reserves in earthworms (Dendrobaena octaedra) from contaminated and uncontaminated forest soil

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Sørensen, Jesper Givskov; Overgaard, Johannes;

    2011-01-01

    . These results suggest that coping with different metals in earthworms is associated with differential energy demands depending on the associated detoxification strategy. Detoxification and accumulation of cadmium and lead by earthworms carries little energetic expenses whereas strict internal regulation......Stress originating from toxicants such as heavy metals can induce compensatory changes in the energy metabolism of organisms due to increased energy expenses associated with detoxification and excretion processes. These energy expenses may be reflected in the available energy reserves...... such as glycogen. In a field study the earthworm, Dendrobaena octaedra, was collected from polluted areas, and from unpolluted reference areas. If present in the environment, cadmium, lead and copper accumulated to high concentrations in D. octaedra. In contrast, other toxic metals such as aluminium, nickel...

  18. Acid hydrolysis and molecular density of phytoglycogen and liver glycogen helps understand the bonding in glycogen α (composite particles.

    Directory of Open Access Journals (Sweden)

    Prudence O Powell

    Full Text Available Phytoglycogen (from certain mutant plants and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired.

  19. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    OpenAIRE

    Terry J. Rose

    2016-01-01

    Enhanced efficiency nitrogen (N) fertilizers (EEFs) may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP) and polymer-coated urea (PCU) to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key minera...

  20. Accumulation of smooth endoplasmic reticulum in Alzheimer's disease: new morphological evidence of axoplasmic flow disturbances.

    OpenAIRE

    Richard, S; Brion, Jean Pierre; Couck, A. M.; Flament Durand, Jacqueline

    1989-01-01

    Numerous enlarged neurites and presynaptic terminals containing tubulovesicular profiles of smooth endoplasmic reticulum (SER) were observed in frontal biopsies from six patients with Alzheimer's disease. These accumulations of SER probably reflect disturbances of axoplasmic flows. In addition, curvilinear tubular inclusions similar to those characteristic of Farber's disease were found in one patient. Finally, accumulation of glycogen within neurites and enlarged mitochondria were observed i...

  1. Glycogen resynthesis rate following cross-country skiing is closely correlated to skeletal muscle glycogen content

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Nielsen, Joachim; Saltin, Bengt;

    INTRODUCTION: In skeletal muscle, glucose is stored as glycogen, which is a major source of energy during most forms of muscle activity. It is now well recognized that muscle glycogen stores are closely related to performance and endurance capacity. Thus, successful competition or training depends....... METHOD: Ten male elite cc skiers (age: 22 ± 0.4 years; height: 181 ± 2 cm; body mass: 78.8 ± 2.6 kg) with a VO2 max of 72 ± 2 [range 62-79] ml . kg-1 . min-1 (5.4 ± 0.5 [range 4.8-6.1] L . min-1) and 700 training hours per year [550 – 850]) volunteered for the study. The skiers performed a ~20 km time......-trial (classic style) on a competition cc track. During the first 4hrs of recovery, skiers received either water or carbohydrate (CHO), after which they all received CHO enriched food (1 g . kg-1 bw . h-1). Muscle biopsies were obtained in both arm and leg muscles before and immediately after the race, as well...

  2. Digestion of glycogen by a glucosidase released by Trichomonas vaginalis.

    Science.gov (United States)

    Huffman, Ryan D; Nawrocki, Lauren D; Wilson, Wayne A; Brittingham, Andrew

    2015-12-01

    Trichomonas vaginalis is a protozoan parasite that is the causative agent of trichomoniasis, a widespread sexually transmitted disease. In vitro culture of T. vaginalis typically employs a medium supplemented with either maltose or glucose and carbohydrates are considered essential for growth. Although the nature of the carbohydrates utilized by T. vaginalis in vivo is undefined, the vaginal epithelium is rich in glycogen, which appears to provide a source of carbon for the vaginal microbiota. Here, we show that T. vaginalis grows equally well in growth media supplemented with simple sugars or with glycogen. Analysis of conditioned growth medium by thin layer chromatography indicates that growth on glycogen is accompanied by glycogen breakdown to a mixture of products including maltose, glucose, and oligosaccharides. Enzymatic assays with conditioned growth medium show that glycogen breakdown is accomplished via the release of a glucosidase activity having the properties of an α-amylase into the growth medium. Furthermore, we find that released glucosidase activity increases upon removal of carbohydrate from the growth medium, indicating regulation of synthesis and/or secretion in response to environmental cues. Lastly, we show that addition of T. vaginalis glucosidase activity to a growth medium containing glycogen generates sufficient simple sugar to support the growth of lactobacilli which, themselves, are unable to degrade glycogen. Thus, not only does the glucosidase activity likely play an important role in allowing T. vaginalis to secure simple sugars for its own use, it has the potential to impact the growth of other members of the vaginal microbiome. PMID:26420465

  3. AIR TEMPERATURE AND SUNLIGHT INTENSITY OF DIFFERENT GROWING PERIOD AFFECTS THE BIOMASS, LEAF COLOR AND BETACYANIN PIGMENT ACCUMULATIONS IN RED AMARANTH (AMARANTHUS TRICOLOR L.

    Directory of Open Access Journals (Sweden)

    Laila KHANDAKER

    2010-06-01

    Full Text Available The objectives of this study were to determine the effects of daily air temperature and sunlight intensity variations on biomass production, leaf color and betacyanin accumulations in red amaranth (Amaranthus tricolor L.. For this purpose, two improved cultivars; BARI-1 and Altopati were grown in seven different period (from April to October, 2006 under vinyl house condition in the experimental facilities of Gifu University, Japan. The mean daily temperatures fluctuated from 18 (growing month- April to 29ºC (August, while the mean sunlight intensities varied from 850 (October to 1257 μmol m-2 S-1 (August. The highest biomass yield and betacyanin accumulation was obtained in the warmer growing period (July and August at 28 to 29ºC mean air temperatures and 1240 to 1257 μmol m-2 S-1 sunlight intensity. At the warmer growing period red amaranth produced red leaves with high color index, which enhanced the betacyanin accumulations. The biomass yield and betacyanin accumulations were reduced significantly in the growing period/month April and October under low temperature regimes (mean air temperature 18 and 19ºC, respectively. However, growing period’s air temperature contributed more for biomass and betacyanin accumulations in red amaranth than sunlight intensity. Comparing two cultivars the biomass yield of BARI-1 was higher biomass yield than that of Altopati and Altopati highlighted with the higher betacyanin accumulations than that of BARI-1 in all growing period. Quantification of the effects of daily air temperature and sunlight intensity on biomass and betacyanin accumulation is important for growers producing these crops for fresh market and also optimize the best growing period. Therefore the influence of air temperatures and sunlight intensity should be considered while grown red amaranth for maximum yield with bioactive compounds like betacyanin and should be grown in between 28 to 29ºC air temperature and 1240 to 1257 μmol.m-2

  4. Endogenous glycogen prevents Ca2+ overload and hypercontracture in harp seal myocardial cells during simulated ischemia.

    Science.gov (United States)

    Henden, Thale; Aasum, Ellen; Folkow, Lars; Mjøs, Ole D; Lathrop, David A; Larsen, Terje S

    2004-07-01

    The purpose of this study was to determine if elevated myocardial glycogen content could obviate Ca(2+) overload and subsequent myocardial injury in the setting of low oxygen and diminished exogenous substrate supplies. Isolated harp seal cardiomyocytes, recognized as having large glycogen stores, were incubated under conditions simulating ischemia (oxygen and substrate deprivation) for 1 h. Rat cardiomyocytes were used for comparison. Freshly isolated seal cardiomyocytes contained approximately 10 times more glycogen than those from rats (479 +/- 39 vs. 48 +/- 5 nmol glucose/mg dry weight (dry wt), mean +/- S.E., n = 6), and during ischemia lactate production was significantly greater in seal compared to rat cardiomyocytes (660 +/- 99 vs. 97 +/- 14 nmol/mg dry wt), while glycogen content decreased both in seal (from 479 +/- 39 to 315 +/- 58 nmol glucose/mg dry wt) and rat cardiomyocytes (from 48 +/- 5 to 18 +/- 5 nmol glucose/mg dry wt). Cellular ATP was well maintained in ischemic seal cardiomyocytes, whereas it showed a 65% decline (from 31 +/- 3 to 11 +/- 1 nmol ATP/mg dry wt) in rat cardiomyocytes. Similarly, total seal cardiomyocyte Ca(2+) content was not affected by ischemia, while Ca(2+) increased from 8.5 +/- 2.0 to 13.3 +/- 2.0 nmol/mg dry wt in ischemic rat myocytes. Rat cardiomyocytes also showed a notable decline in the percentage of rod-shaped cells in response to ischemia (from 66 +/- 4% to 30 +/- 3%), and cell morphology was unaffected in seal incubations. Addition of iodoacetate (IAA, an inhibitor of glycolysis) to seal cardiomyocytes, on top of substrate and oxygen deprivation, reduced the cellular content of ATP by 52.9 +/- 4.4% (from 25 +/- 4 to 11 +/- 2 nmol ATP/mg dry wt) and the percentage of rod-shaped myocytes from 51 +/- 3% to 28 +/- 4%, while total Ca(2+) content was unchanged by these conditions. Seal cardiomyocytes thus tolerate low oxygen conditions better than rat cardiomyocytes. This finding is most likely due to a higher glycolysis

  5. Effects of diabetes on brain metabolism - is brain glycogen a significant player?

    DEFF Research Database (Denmark)

    Sickmann, Helle M; Waagepetersen, Helle S.

    2015-01-01

    be associated with brain impairments e.g. cognitive decline and dementia. It is however, not clear how these impairments on brain function are linked to alterations in brain energy and neurotransmitter metabolism. In this review, we will illuminate how rodent diabetes models have contributed to a...... better understanding of how brain energy and neurotransmitter metabolism is affected in diabetes. There will be a particular focus on the role of brain glycogen to support glycolytic and TCA cycle activity as well as glutamate-glutamine cycle in type 1 and type 2 diabetes....

  6. Trade-Off between Growth and Carbohydrate Accumulation in Nutrient-Limited Arthrospira sp. PCC 8005 Studied by Integrating Transcriptomic and Proteomic Approaches.

    Directory of Open Access Journals (Sweden)

    Orily Depraetere

    Full Text Available Cyanobacteria have a strong potential for biofuel production due to their ability to accumulate large amounts of carbohydrates. Nitrogen (N stress can be used to increase the content of carbohydrates in the biomass, but it is expected to reduce biomass productivity. To study this trade-off between carbohydrate accumulation and biomass productivity, we characterized the biomass productivity, biomass composition as well as the transcriptome and proteome of the cyanobacterium Arthrospira sp. PCC 8005 cultured under N-limiting and N-replete conditions. N limitation resulted in a large increase in the carbohydrate content of the biomass (from 14 to 74% and a decrease in the protein content (from 37 to 10%. Analyses of fatty acids indicated that no lipids were accumulated under N-limited conditions. Nevertheless, it did not affect the biomass productivity of the culture up to five days after N was depleted from the culture medium. Transcriptomic and proteomic analysis indicated that de novo protein synthesis was down-regulated in the N-limited culture. Proteins were degraded and partly converted into carbohydrates through gluconeogenesis. Cellular N derived from protein degradation was recycled through the TCA and GS-GOGAT cycles. In addition, photosynthetic energy production and carbon fixation were both down-regulated, while glycogen synthesis was up-regulated. Our results suggested that N limitation resulted in a redirection of photosynthetic energy from protein synthesis to glycogen synthesis. The fact that glycogen synthesis has a lower energy demand than protein synthesis might explain why Arthrospira is able to achieve a similar biomass productivity under N-limited as under N-replete conditions despite the fact that photosynthetic energy production was impaired by N limitation.

  7. A new non-degradative method to purify glycogen.

    Science.gov (United States)

    Tan, Xinle; Sullivan, Mitchell A; Gao, Fei; Li, Shihan; Schulz, Benjamin L; Gilbert, Robert G

    2016-08-20

    Liver glycogen, a complex branched glucose polymer containing a small amount of protein, is important for maintaining glucose homeostasis (blood-sugar control) in humans. It has recently been found that glycogen molecular structure is impaired in diabetes. Isolating the carbohydrate polymer and any intrinsically-attached protein(s) is an essential prerequisite for studying this structural impairment. This requires an effective, non-degradative and efficient purification method to exclude the many other proteins present in liver. Proteins and glycogen have different ranges of molecular sizes. Despite the plethora of proteins that might still be present in significant abundance after other isolation techniques, SEC (size exclusion chromatography, also known as GPC), which separates by molecular size, should separate those extraneous to glycogen from glycogen with any intrinsically associated protein(s). A novel purification method is developed for this, based on preparative SEC following sucrose gradient centrifugation. Proteomics is used to show that the new method compares favourably with current methods in the literature. PMID:27178921

  8. Glucose uptake and transport in contracting, perfused rat muscle with different pre-contraction glycogen concentrations

    DEFF Research Database (Denmark)

    Hespel, P; Richter, Erik

    1990-01-01

    , resulting in either low (glycogen-depleted rats), normal (control rats) or high (supercompensated rats) muscle glycogen concentrations at the time their hindlimbs were perfused. 2. Compared with control rats, pre-contraction muscle glycogen concentration was approximately 40% lower in glycogen-depleted rats......, whereas it was 40% higher in supercompensated rats. Muscle glycogen break-down correlated positively (r = 0.76; P less than 0.001) with pre-contraction muscle glycogen concentration. 3. Glucose uptake during contractions was approximately 50% higher in glycogen-depleted hindquarters than in control...... hindquarters; in supercompensated hindquarters it was 30% lower. When rats with similar muscle glycogen concentrations were compared, glucose uptake in hindquarters from rats that had exercised on the preceding day was approximately 20% higher than in hindquarters from rats that had not exercised on the...

  9. Fat balance in obese subjects: role of glycogen stores.

    OpenAIRE

    Schrauwen, P; van Marken Lichtenbelt, W.D.; Westerterp, K.R.

    1998-01-01

    Department of Human Biology, Maastricht University, 6200 MD Maastricht, The Netherlands. In a previous study, we showed that lean subjects are capable of rapidly adjusting fat oxidation to fat intake on a high-fat (HF) diet when glycogen stores are lowered by exhaustive exercise. However, it has been proposed that obese subjects have impaired fat oxidation. We therefore studied the effect of low glycogen stores on fat oxidation after a switch from a reduced-fat (RF) diet to an HF diet in obes...

  10. Glycogen-rich clear cell carcinoma of the breast

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Paulsen, S M

    1987-01-01

    cells were stained by antisera to carcinoembryonic antigen, keratin and epithelial membrane antigen, but not by antisera to alpha-lactalbumin, desmin or vimentin. Ultrastructurally, the epithelial derivation of the tumour was confirmed. Only a few intracytoplasmic lumina were demonstrated. The tumour......The light microscopic, immunohistochemical and ultrastructural features of a clear cell carcinoma of the breast have been studied. Both intraductal and invasive components were found. Histochemistry showed large amounts of intracytoplasmic glycogen and sparse neutral mucin in the tumour. The tumour...... was classified as a mucin-containing variant of glycogen-rich, clear cell carcinoma of the breast....

  11. Ultrastructural analysis of glycogen in hippocampal astrocytic processes using 3D virtual reality

    OpenAIRE

    Corrado Calì; Anna Kreshuk; Madhusudhanan Srinivasan

    2015-01-01

    Glycogen is a major energy store in astrocytes that provides energy support and signals for plasticity to neurons under the form of lactate. While the biochemistry of glycogen is well known, the spatial distribution of glycogen granules within astrocytes remains largely unknown. Recent studies show that glycogen-derived lactate is necessary for synaptic plasticity and memory formation in the hippocampus, but the predominant subcellular target, pre- and post-synaptic profiles, of lactate remai...

  12. AIR TEMPERATURE AND SUNLIGHT INTENSITY OF DIFFERENT GROWING PERIOD AFFECTS THE BIOMASS, LEAF COLOR AND BETACYANIN PIGMENT ACCUMULATIONS IN RED AMARANTH (AMARANTHUS TRICOLOR L.)

    OpenAIRE

    Laila KHANDAKER; A AKOND; OBA, Shinya

    2010-01-01

    The objectives of this study were to determine the effects of daily air temperature and sunlight intensity variations on biomass production, leaf color and betacyanin accumulations in red amaranth (Amaranthus tricolor L.). For this purpose, two improved cultivars; BARI-1 and Altopati were grown in seven different period (from April to October, 2006) under vinyl house condition in the experimental facilities of Gifu University, Japan. The mean daily temperatures fluctuated from 18 (growing ...

  13. Relative contribution of food and water to 27 metals and metalloids accumulated by caged Hyalella azteca in two rivers affected by metal mining

    International Nuclear Information System (INIS)

    Hyalella were caged at three sites in each of the two rivers for 17 days. Food added to the cages consisted of plant and detrital material collected from the same, or other, sites. Concentrations of some metals in Hyalella (e.g., Cd and Cu), but not others (e.g., Se), appeared to reach steady-state within 5 days in one of the rivers. Metal accumulation was minimal by day 5 in the other river, possibly due to the very low temperatures in this river for the first part of the exposure period. Both analysis of variance and analysis of covariance, using site as a categorical variable and metal in food as either a categorical or continuous variable, indicated that Cd, Cu and Se were the only metals for which concentration in food had a significant effect on concentration in Hyalella. Nevertheless, water was still a major source for these metals as well. Other metals which varied by over fivefold in food but for which concentration in food had no effect on concentration in Hyalella included Ag, As, Bi, Sb, U and Zn. Concentrations of the remaining metals varied less than fourfold in food, making it difficult to determine if these were accumulated from food. - Cadmium, copper and selenium were the only metals in food that correlated with increased body concentrations of metals in Hyalella, but even these metals were accumulated largely from water

  14. Relative contribution of food and water to 27 metals and metalloids accumulated by caged Hyalella azteca in two rivers affected by metal mining

    Energy Technology Data Exchange (ETDEWEB)

    Borgmann, U. [Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, L7R 4A6 (Canada)]. E-mail: uwe.borgmann@ec.gc.ca; Couillard, Y. [Existing Substances Division, Environment Canada, 351 Saint-Joseph Boulevard, Gatineau, QC, K1A 0H3 (Canada); Grapentine, L.C. [Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, L7R 4A6 (Canada)

    2007-02-15

    Hyalella were caged at three sites in each of the two rivers for 17 days. Food added to the cages consisted of plant and detrital material collected from the same, or other, sites. Concentrations of some metals in Hyalella (e.g., Cd and Cu), but not others (e.g., Se), appeared to reach steady-state within 5 days in one of the rivers. Metal accumulation was minimal by day 5 in the other river, possibly due to the very low temperatures in this river for the first part of the exposure period. Both analysis of variance and analysis of covariance, using site as a categorical variable and metal in food as either a categorical or continuous variable, indicated that Cd, Cu and Se were the only metals for which concentration in food had a significant effect on concentration in Hyalella. Nevertheless, water was still a major source for these metals as well. Other metals which varied by over fivefold in food but for which concentration in food had no effect on concentration in Hyalella included Ag, As, Bi, Sb, U and Zn. Concentrations of the remaining metals varied less than fourfold in food, making it difficult to determine if these were accumulated from food. - Cadmium, copper and selenium were the only metals in food that correlated with increased body concentrations of metals in Hyalella, but even these metals were accumulated largely from water.

  15. Depletion of acyl-coenzyme A-binding protein affects sphingolipid synthesis and causes vesicle accumulation and membrane defects in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Gaigg, B; Neergaard, T B; Schneiter, R; Hansen, J.K.; Faergeman, N J; Jensen, N A; Andersen, J R; Friis, J; Sandhoff, R; Schrøder, H D; Knudsen, J

    2001-01-01

    -70%. The reduced incorporation of [(3)H]myo-inositol into sphingolipids was due to a reduced incorporation into inositol-phosphoceramide and mannose-inositol-phosphoceramide only, a pattern that is characteristic for cells with aberrant endoplasmic reticulum to Golgi transport. The plasma membrane of the...... Acb1p-depleted strain contained increased levels of inositol-phosphoceramide and mannose-inositol-phosphoceramide and lysophospholipids. Acb1p-depleted cells accumulated 50- to 60-nm vesicles and autophagocytotic like bodies and showed strongly perturbed plasma membrane structures. The present results...

  16. Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats

    DEFF Research Database (Denmark)

    Galbo, H; Saugmann, P; Richter, Erik

    1979-01-01

    Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other...

  17. Glycogen as a biodegradable polymer carrier for diagnostics

    Czech Academy of Sciences Publication Activity Database

    Hrubý, Martin; Filippov, Sergey K.; Sedláček, Ondřej; Vetrík, Miroslav; Kovář, J.; Jirák, D.

    Pisa : European Polymer Federation, 2013. O6-16. [European Polymer Congress - EPF 2013. 16.06.2013-21.06.2013, Pisa] R&D Projects: GA ČR GA13-08336S Grant ostatní: AV ČR(CZ) M200501201 Institutional support: RVO:61389013 Keywords : nanoparticles * in vivo imaging * glycogen Subject RIV: CA - Inorganic Chemistry

  18. Enzymatic description of the anhydrofructose pathway of glycogen degradation. I

    DEFF Research Database (Denmark)

    Yu, Shukun; Refdahl, Charlotte; Lundt, Inge

    2004-01-01

    The anhydrofructose pathway describes the degradation of glycogen and starch to metabolites via 1,5-anhydro-D-fructose (1,5AnFru). The enzyme catalyzing the first reaction step of this pathway, i.e., a-1,4-glucan lyase (EC 4.2.1.13), has been purified, cloned and characterized from fungi and red ...

  19. Chronic ethanol consumption disrupts diurnal rhythms of hepatic glycogen metabolism in mice

    Science.gov (United States)

    Udoh, Uduak S.; Swain, Telisha M.; Filiano, Ashley N.; Gamble, Karen L.; Young, Martin E.

    2015-01-01

    Chronic ethanol consumption has been shown to significantly decrease hepatic glycogen content; however, the mechanisms responsible for this adverse metabolic effect are unknown. In this study, we examined the impact chronic ethanol consumption has on time-of-day-dependent oscillations (rhythms) in glycogen metabolism processes in the liver. For this, male C57BL/6J mice were fed either a control or ethanol-containing liquid diet for 5 wk, and livers were collected every 4 h for 24 h and analyzed for changes in various genes and proteins involved in hepatic glycogen metabolism. Glycogen displayed a robust diurnal rhythm in the livers of mice fed the control diet, with the peak occurring during the active (dark) period of the day. The diurnal glycogen rhythm was significantly altered in livers of ethanol-fed mice, with the glycogen peak shifted into the inactive (light) period and the overall content of glycogen decreased compared with controls. Chronic ethanol consumption further disrupted diurnal rhythms in gene expression (glycogen synthase 1 and 2, glycogenin, glucokinase, protein targeting to glycogen, and pyruvate kinase), total and phosphorylated glycogen synthase protein, and enzyme activities of glycogen synthase and glycogen phosphorylase, the rate-limiting enzymes of glycogen metabolism. In summary, these results show for the first time that chronic ethanol consumption disrupts diurnal rhythms in hepatic glycogen metabolism at the gene and protein level. Chronic ethanol-induced disruption in these daily rhythms likely contributes to glycogen depletion and disruption of hepatic energy homeostasis, a recognized risk factor in the etiology of alcoholic liver disease. PMID:25857999

  20. Fenton process-affected transformation of roxarsone in paddy rice soils: Effects on plant growth and arsenic accumulation in rice grain.

    Science.gov (United States)

    Qin, Junhao; Li, Huashou; Lin, Chuxia

    2016-08-01

    Batch and greenhouse experiments were conducted to examine the effects of Fenton process on transformation of roxarsone in soils and its resulting impacts on the growth of and As uptake by a rice plant cultivar. The results show that addition of Fenton reagent markedly accelerated the degradation of roxarsone and produced arsenite, which was otherwise absent in the soil without added Fenton reagent. Methylation of arsenate was also enhanced by Fenton process in the earlier part of the experiment due to abundant supply of arsenate from Roxarsone degradation. Overall, addition of Fenton reagent resulted in the predominant presence of arsenate in the soils. Fenton process significantly improved the growth of rice in the maturity stage of the first crop, The concentration of methylated As species in the rice plant tissues among the different growth stages was highly variable. Addition of Fenton reagent into the soils led to reduced uptake of soil-borne As by the rice plants and this had a significant effect on reducing the accumulation of As in rice grains. The findings have implications for understanding As biogeochemistry in paddy rice field receiving rainwater-borne H2O2 and for development of mitigation strategies to reduce accumulation of As in rice grains. PMID:27060198

  1. Effect of carbon tetrachloride on glycogen metabolism in fasted and refed mice

    International Nuclear Information System (INIS)

    Hepatic glycogen was depleted rapidly in fasted mice treated with CCl4. Glycogen breakdown was slow when CCl4 was administered after 1 hr of refeeding. There was an initial increase and then a reduction in liver glycogen of mice refed for 2 hr prior to CCl4 injection. The incorporation of glucose-U-14C into glycogen was higher in mice which were refed before CCl4 administration than in fasted mice treated with the hepatotoxin. The specific activity of lactate was higher in CCl4 treated mice. The data suggested differences in glycogen metabolism of fasted and refed mice in response to CCl4 treatment. (author)

  2. Supercompensation of muscle glycogen in trained and untrained subjects.

    Science.gov (United States)

    Roedde, S; MacDougall, J D; Sutton, J R; Green, H J

    1986-03-01

    The purpose of this study was to determine whether or not trained athletes have the same capacity for supercompensation of muscle glycogen as untrained subjects. Muscle glycogen was measured in 4 highly trained cyclists and 4 untrained controls over a 6 day period of exercise and dietary manipulation. During the week prior to the investigation the trained group tapered their training load but maintained a high carbohydrate intake as they would in preparation for a major competition. Needle biopsies were taken from the vastus lateralis before and after exhaustive cycle ergometry at 73% VO2 max followed by several sprint intervals, after 3 days on a carbohydrate-restricted diet and after 2 and 3 days on a high carbohydrate diet. All food intake was quantified and plasma insulin and glucose were monitored daily. The mean initial glycogen concentration for the trained group was 115 mmol X kg-1 wet muscle weight and 92 mmol X kg-1 for the untrained group. Both groups showed similar post exercise depletion and recovery patterns when expressed as a % of their initial values. Following 3 days of high carbohydrate diet, the glycogen concentration for the trained cyclists reached 174 mmol X kg-1 or 152% of its initial value while the untrained-group reached 143 mmol X kg-1 or 155% of its initial value. It was concluded that a regimen of exhaustive exercise, followed by a period of carbohydrate restriction and a period of high carbohydrate intake, results in substantially higher muscle glycogen storage than can be achieved by a reduction in training in combination with high carbohydrate intake.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3698159

  3. In Vitro Palmitate Treatment of Myotubes from Postmenopausal Women Leads to Ceramide Accumulation, Inflammation and Affected Insulin Signaling

    DEFF Research Database (Denmark)

    Abildgaard, Julie; Henstridge, Darren C; Pedersen, Anette Tønnes;

    2014-01-01

    Menopause is associated with an increased incidence of insulin resistance and metabolic diseases. In a chronic palmitate treatment model, we investigated the role of skeletal muscle fatty acid exposure in relation to the metabolic deterioration observed with menopause. Human skeletal muscle...... satellite cells were isolated from premenopausal (n = 6) and postmenopausal (n = 5) women. In an in vitro model, the myotubes were treated with palmitate (300 µM) for one-, two- or three days during differentiation. Effects on lipid accumulation, inflammation and insulin signaling were studied. Palmitate......, post-myotubes showed a blunted insulin stimulated phosphorylation of AS160 in response to chronic palmitate treatment compared with pre-myotubes (p = 0.02). The increased intramyocellular ceramide content in the post-myotubes was associated with a significantly higher mRNA expression of Serine...

  4. Factors affecting accumulation of thallium and other trace elements in two wild Brassicaceae spontaneously growing on soils contaminated by tailings dam waste.

    Science.gov (United States)

    Madejón, P; Murillo, J M; Marañón, T; Lepp, N W

    2007-02-01

    Thallium is a scarce, highly toxic element. There are several investigations that report Tl accumulation in plants of the family Brassicaceae. These plants could pose a risk in areas where Tl is present at higher concentrations than normal soils. The present study reports analyses of two wild Brassicaceae, Hirschfeldia incana and Diplotaxis catholica, growing spontaneously at five sampling sites moderately polluted with Tl and other trace elements in the Green Corridor of the Guadiamar river, Seville, S. Spain. In general, trace element content was unremarkable in all part plants, despite the concentrations present in soil. Thallium was the only element whose concentration in both plant species was above normal for plants (maximum values of 5.00 mgkg(-1) in H. incana flowers). There were significant positive correlations between total Tl in soil and Tl in both plant species. Transfer Coefficients (TC) for all elements were, in general, <1 for both species, except for Tl in flowers and fruits at some sites. The highest Enrichment Factor (EF) was found for Tl in H. incana fruits (EF = 607) and D. catholica flowers (EF = 321). H. incana was studied in a previous growing season (2004) in the same area, although the rainfall was 3 times more than in the year of the present study (2005), giving a maximum Tl content of 46.5 mgkg(-1) in H. incana flowers. The data presented here show that Tl content of plants growing in semi-arid conditions can be significantly influenced by precipitation. In dry years, plant Tl accumulation may be significantly reduced. PMID:17123576

  5. Effect of intraperitoneal selenium administration on liver glycogen levels in rats subjected to acute forced swimming.

    Science.gov (United States)

    Akil, Mustafa; Bicer, Mursel; Kilic, Mehmet; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

    2011-03-01

    There are a few of studies examining how selenium, which is known to reduce oxidative damage in exercise, influences glucose metabolism and exhaustion in physical activity. The present study aims to examine how selenium administration affects liver glycogen levels in rats subjected to acute swimming exercise. The study included 32 Sprague-Dawley type male rats, which were equally allocated to four groups: Group 1, general control; Group 2; selenium-supplemented control (6 mg/kg/day sodium selenite); Group 3, swimming control; Group 4, selenium-supplemented swimming (6 mg/kg/day sodium selenite). Liver tissue samples collected from the animals at the end of the study were fixed in 95% ethyl alcohol. From the tissue samples buried into paraffin, 5-µm cross-sections were obtained using a microtome, put on a microscope slide, and stained with PAS. Stained preparations were assessed using a Nikon Eclipse E400 light microscope. All images obtained with the light microscope were transferred to a PC and evaluated using Clemex PE 3.5 image analysis software. The highest liver glycogen levels were found in groups 1 and 2 (p exercise can be restored by selenium administration. It can be argued that physiological doses of selenium administration can contribute to performance. PMID:20340052

  6. Trophic transfer and accumulation of mercury in ray species in coastal waters affected by historic mercury mining (Gulf of Trieste, northern Adriatic Sea).

    Science.gov (United States)

    Horvat, Milena; Degenek, Nina; Lipej, Lovrenc; Snoj Tratnik, Janja; Faganeli, Jadran

    2014-03-01

    Total mercury (Hg) and monomethylmercury (MMHg) were analysed in the gills, liver and muscle of four cartilaginous fish species (top predators), namely, the eagle ray (Myliobatis aquila), the bull ray (Pteromylaeus bovinus), the pelagic stingray (Dasyatis violacea) and the common stingray (Dasyatis pastinaca), collected in the Gulf of Trieste, one of the most Hg-polluted areas in the Mediterranean and worldwide due to past mining activity in Idrija (West Slovenia). The highest Hg and MMHg concentrations expressed on a dry weight (d.w.) basis were found in the muscle of the pelagic stingray (mean, 2.529 mg/kg; range, 1.179-4.398 mg/kg, d.w.), followed by the bull ray (mean, 1.582 mg/kg; range, 0.129-3.050 mg/kg d.w.) and the eagle ray (mean, 0.222 mg/kg; range, 0.070-0.467 mg/kg, d.w.). Only one specimen of the common stingray was analysed, with a mean value in the muscle of 1.596 mg/kg, d.w. Hg and MMHg contents in the bull ray were found to be positively correlated with species length and weight. The highest MMHg accumulation was found in muscle tissue. Hg and MMHg were also found in two embryos of a bull ray, indicating Hg transfer from the mother during pregnancy. The number of specimens and the size coverage of the bull rays allowed an assessment of Hg accumulation with age. It was shown that in bigger bull ray specimens, the high uptake of inorganic Hg in the liver and the slower MMHg increase in the muscle were most probably due to the demethylation of MMHg in the liver. The highest Hg and MMHg contents in all organs were found in the pelagic stingray, which first appeared in the northern Adriatic in 1999. High Hg and MMHg concentrations were also found in prey species such as the banded murex (Hexaplex trunculus), the principal prey of the eagle rays and bull rays, the anchovy (Engraulis encrasicholus) and the red bandfish (Cepola rubescens), which are preyed upon by the pelagic stingray, as well as in zooplankton and seawater. Based on previously published

  7. Oligopoly banking and capital accumulation

    OpenAIRE

    Nicola Cetorelli; Pietro F. Peretto

    2000-01-01

    We develop a dynamic general equilibrium model of capital accumulation where credit is intermediated by banks operating in a Cournot oligopoly. The number of banks affects capital accumulation through two channels. First, it affects the quantity of credit available to entrepreneurs. Second, it affects banks' decisions to collect costly information about entrepreneurs, and thus determines the efficiency of the credit market. We show that under plausible conditions, the market structure that ma...

  8. Exercise intolerance in Glycogen Storage Disease Type III

    DEFF Research Database (Denmark)

    Preisler, Nicolai; Pradel, Agnès; Husu, Edith;

    2013-01-01

    Myopathic symptoms in Glycogen Storage Disease Type IIIa (GSD IIIa) are generally ascribed to the muscle wasting that these patients suffer in adult life, but an inability to debranch glycogen likely also has an impact on muscle energy metabolism. We hypothesized that patients with GSD IIIa can...... experience exercise intolerance due to insufficient carbohydrate oxidation in skeletal muscle. Six patients aged 17-36-years were studied. We determined VO 2peak (peak oxygen consumption), the response to forearm exercise, and the metabolic and cardiovascular responses to cycle exercise at 70% of VO 2peak...... capacity was significantly reduced, and our results indicate that this was due to a block in muscle glycogenolytic capacity. Our findings suggest that the general classification of GSD III as a glycogenosis characterized by fixed symptoms related to muscle wasting should be modified to include dynamic...

  9. Glucose uptake and glycogen synthesis in adult Necator americanus

    International Nuclear Information System (INIS)

    The uptake of 14C glucose by N. americanus in Kreb's solution at 37deg C was studied. The results showed that glucose is taken up in the presence of host serum in the incubation medium. The uptake of radioactivity was similar when the incubations were carried out in an atmosphere of oxygen or nitrogen. The parasite was also capable of incorporating glucose into glycogen. No difference in the incorporation was seen when the incubations were carried out in the presence and absence of serum. However incorporation was significantly reduced to 0deg-4deg C. It is concluded that glucose is taken up, gets incorporated into the glycogen and this may be a source of nutrition for the hookworm parasite. (author)

  10. Impaired glycogen synthase activity and mitochondrial dysfunction in skeletal muscle

    DEFF Research Database (Denmark)

    Højlund, Kurt; Beck-Nielsen, Henning

    2006-01-01

    Insulin resistance in skeletal muscle is a major hallmark of type 2 diabetes and an early detectable abnormality in the development of this disease. The cellular mechanisms of insulin resistance include impaired insulin-mediated muscle glycogen synthesis and increased intramyocellular lipid content...... expression analysis and proteomics have pointed to abnormalities in mitochondrial oxidative phosphorylation and cellular stress in muscle of type 2 diabetic subjects, and recent work suggests that impaired mitochondrial activity is another early defect in the pathogenesis of type 2 diabetes. This review will...... discuss the latest advances in the understanding of the molecular mechanisms underlying insulin resistance in human skeletal muscle in type 2 diabetes with focus on possible links between impaired glycogen synthase activity and mitochondrial dysfunction....

  11. Glycogen storage disease type III: modified Atkins diet improves myopathy

    OpenAIRE

    Mayorandan, Sebene; Meyer, Uta; Hartmann, Hans; Das, Anibh Martin

    2014-01-01

    Background Frequent feeds with carbohydrate-rich meals or continuous enteral feeding has been the therapy of choice in glycogen storage disease (Glycogenosis) type III. Recent guidelines on diagnosis and management recommend frequent feedings with high complex carbohydrates or cornstarch avoiding fasting in children, while in adults a low-carb-high-protein-diet is recommended. While this regimen can prevent hypoglycaemia in children it does not improve skeletal and heart muscle function, whic...

  12. Mechanisms limiting glycogen storage in muscle during prolonged insulin stimulation

    DEFF Research Database (Denmark)

    Richter, Erik; Hansen, S A; Hansen, B F

    1988-01-01

    increased muscle glycogen concentrations to maximal values 2, 3, and 3.5 times above normal fed levels in fast-twitch white, slow-twitch red, and fast-twitch red fibers, respectively. Glucose uptake decreased (mean +/- SE) from 34.9 +/- 1.2 mumol.g-1.h-1 at 0 h to 7.5 +/- 0.7 after 7 h of perfusion. During...

  13. New inhibitors of glycogen phosphorylase as potential antidiabetic agents.

    Science.gov (United States)

    Somsák, L; Czifrák, K; Tóth, M; Bokor, E; Chrysina, E D; Alexacou, K-M; Hayes, J M; Tiraidis, C; Lazoura, E; Leonidas, D D; Zographos, S E; Oikonomakos, N G

    2008-01-01

    The protein glycogen phosphorylase has been linked to type 2 diabetes, indicating the importance of this target to human health. Hence, the search for potent and selective inhibitors of this enzyme, which may lead to antihyperglycaemic drugs, has received particular attention. Glycogen phosphorylase is a typical allosteric protein with five different ligand binding sites, thus offering multiple opportunities for modulation of enzyme activity. The present survey is focused on recent new molecules, potential inhibitors of the enzyme. The biological activity can be modified by these molecules through direct binding, allosteric effects or other structural changes. Progress in our understanding of the mechanism of action of these inhibitors has been made by the determination of high-resolution enzyme inhibitor structures (both muscle and liver). The knowledge of the three-dimensional structures of protein-ligand complexes allows analysis of how the ligands interact with the target and has the potential to facilitate structure-based drug design. In this review, the synthesis, structure determination and computational studies of the most recent inhibitors of glycogen phosphorylase at the different binding sites are presented and analyzed. PMID:19075645

  14. Factors Altering Pyruvate Excretion in a Glycogen Storage Mutant of the Cyanobacterium, Synechococcus PCC7942.

    Science.gov (United States)

    Benson, Phoebe J; Purcell-Meyerink, Diane; Hocart, Charles H; Truong, Thy T; James, Gabriel O; Rourke, Loraine; Djordjevic, Michael A; Blackburn, Susan I; Price, G D

    2016-01-01

    Interest in the production of carbon commodities from photosynthetically fixed CO2 has focused attention on cyanobacteria as a target for metabolic engineering and pathway investigation. We investigated the redirection of carbon flux in the model cyanobacterial species, Synechococcus elongatus PCC 7942, under nitrogen deprivation, for optimized production of the industrially desirable compound, pyruvate. Under nitrogen limited conditions, excess carbon is naturally stored as the multi-branched polysaccharide, glycogen, but a block in glycogen synthesis, via knockout mutation in the gene encoding ADP-glucose pyrophosphorylase (glgC), results in the accumulation of the organic acids, pyruvate and 2-oxoglutarate, as overflow excretions into the extracellular media. The ΔglgC strain, under 48 h of N-deprivation was shown to excrete pyruvate for the first time in this strain. Additionally, by increasing culture pH, to pH 10, it was possible to substantially elevate excretion of pyruvate, suggesting the involvement of an unknown substrate/proton symporter for export. The ΔglgC mutant was also engineered to express foreign transporters for glucose and sucrose, and then grown photomixotrophically with exogenous organic carbon supply, as added 5 mM glucose or sucrose during N- deprivation. Under these conditions we observed a fourfold increase in extracellular pyruvate excretion when glucose was added, and a smaller increase with added sucrose. Although the magnitude of pyruvate excretion did not correlate with the capacity of the ΔglgC strain for bicarbonate-dependent photosynthetic O2 evolution, or with light intensity, there was, however, a positive correlation observed between the density of the starter culture prior to N-deprivation and the final extracellular pyruvate concentration. The factors that contribute to enhancement of pyruvate excretion are discussed, as well as consideration of whether the source of carbon for pyruvate excretion might be derived from

  15. Nitrogen ({sup 15}N) accumulation in corn grains as affected by source of nitrogen in red latosol;Acumulo de nitrogenio ({sup 15}N) pelos graos de milho em funcao da fonte nitrogenada em latossolo vermelho

    Energy Technology Data Exchange (ETDEWEB)

    Duete, Robson Rui Cotrim, E-mail: rrcduete@oi.com.b [Empresa Baiana de Desenvolvimento Agricola S.A. (EBDA), Cruz das Almas, BA (Brazil); Muraoka, Takashi; Trivelin, Paulo Cesar Ocheuze; Silva, Edson Cabral da, E-mail: muraoka@cena.usp.b, E-mail: pcotrive@cena.usp.b, E-mail: ecsilva@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Ambrosano, Edmilson Jose, E-mail: ambrosano@aptaregional.sp.gov.b [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Piracicaba, SP (Brazil). Polo Centro Sul

    2009-07-01

    Nitrogen is the most absorbed mineral nutrient by corn crop and most affects grains yield. It is the unique nutrient absorbed by plants as cation (NH{sub 4}{sup +}) or anion (NO{sub 3}{sup -}). The objectives of this work were to investigate the N accumulation by corn grains applied to the soil as NH{sub 4}{sup +} or NO{sub 3}{sup -} in the ammonium nitrate form compared to amidic form of the urea, labeled with {sup 15}N; to determine the corn growth stage with highest fertilizer N utilization by the grains, and to quantify soil nitrogen exported by corn grains. The study was carried out in the Experimental Station of the Regional Pole of the Sao Paulo Northwestern Agribusiness Development (APTA), in Votuporanga, State of Sao Paulo, Brazil, in a Red Latosol. The experimental design was completely randomized blocks, with 13 treatments and four replications, disposed in factorial outline 6x2 + 1 (control, without N application). A nitrogen rate equivalent to 120 kg N ha-1 as urea-{sup 15}N or as ammonium nitrate, labeled in the cation NH{sub 4}{sup +} ({sup 15}NH{sub 4}{sup +}NO{sub 3}{sup -}) or in the anion NO{sub 3}{sup -} (NH{sub 4}{sup +}15N+O{sub 3}{sup -} ), was applied in six fractions of 20 kg N ha-1 each, in different microplots, from seeding to the growth stage 7 (pasty grains). The forms of nitrogen, NH{sub 4}{sup +}-N and N{sub O}{sup 3}--N, were accumulated equitably by corn grains. The corn grains accumulated more N from urea than from ammonium nitrate. The N applied to corn crop at eight expanded leaves stage promoted largest accumulation of this nutrient in the grains. (author)

  16. Use of deuterium labelled glucose in evaluating the pathway of hepatic glycogen synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, M.N.; Masuoka, L.K.; deRopp, J.S.; Jones, A.D.

    1989-03-15

    Deuterium labelled glucose has been used to study the pathway of hepatic glycogen synthesis during the fasted-refed transition in rats. Deuterium enrichment of liver glycogen was determined using nuclear magnetic resonance as well as mass spectroscopy. Sixty minutes after oral administration of deuterated glucose to fasted rats, the portal vein blood was fully enriched with deuterated glucose. Despite this, less than half of the glucose molecules incorporated into liver glycogen contained deuterium. The loss of deuterium label from glucose is consistent with hepatic glycogen synthesis by an indirect pathway requiring prior metabolism of glucose. The use of deuterium labelled glucose may prove to be a useful probe to study hepatic glycogen metabolism. Its use may also find application in the study of liver glycogen metabolism in humans by a noninvasive means.

  17. Postexercise muscle glycogen resynthesis in obese insulin-resistant Zucker rats.

    Science.gov (United States)

    Bruce, C R; Lee, J S; Hawley, J A

    2001-10-01

    We determined the effect of an acute bout of swimming (8 x 30 min) followed by either carbohydrate administration (0.5 mg/g glucose ip and ad libitum access to chow; CHO) or fasting (Fast) on postexercise glycogen resynthesis in soleus muscle and liver from female lean (ZL) and obese insulin-resistant (ZO) Zucker rats. Resting soleus muscle glycogen concentration ([glycogen]) was similar between genotypes and was reduced by 73 (ZL) and 63% (ZO) after exercise (P supercompensation in both genotypes (68% vs. 44% for ZL and ZO). With CHO, liver [glycogen] was restored to resting levels in ZL but remained at postexercise values for ZO after both treatments. We conclude that the increased glucose availability with carbohydrate refeeding after glycogen-depleting exercise resulted in glycogen supercompensation, even in the face of muscle insulin-resistance. PMID:11568131

  18. Impact of carbohydrate supplementation during endurance training on glycogen storage and performance

    DEFF Research Database (Denmark)

    Nybo, Lars; Pedersen, K.; Christensen, B.;

    2009-01-01

    ingestion. Methods: In previously untrained males performance and various muscular adaptations were evaluated before and after 8 weeks of supervised endurance training conducted either with (n = 8; CHO group) or without (n = 7; placebo) glucose supplementation. Results: The two groups achieved similar......Abstract Aim: Glucose ingestion may improve exercise endurance, but it apparently also influences the transcription rate of several metabolic genes and it alters muscle metabolism during an acute exercise bout. Therefore, we investigated how chronic training responses are affected by glucose.......05), while resting muscle glycogen increased (P < 0.05) to a larger extent in the placebo group (96 +/- 4%) than CHO (33 +/- 2%). Conclusion: These results show that carbohydrate supplementation consumed during exercise training influences various muscular training adaptations, but improvements in...

  19. Glycogen Storage Disease Type Ia in Canines: A Model for Human Metabolic and Genetic Liver Disease

    Directory of Open Access Journals (Sweden)

    Andrew Specht

    2011-01-01

    Full Text Available A canine model of Glycogen storage disease type Ia (GSDIa is described. Affected dogs are homozygous for a previously described M121I mutation resulting in a deficiency of glucose-6-phosphatase-α. Metabolic, clinicopathologic, pathologic, and clinical manifestations of GSDIa observed in this model are described and compared to those observed in humans. The canine model shows more complete recapitulation of the clinical manifestations seen in humans including “lactic acidosis”, larger size, and longer lifespan compared to other animal models. Use of this model in preclinical trials of gene therapy is described and briefly compared to the murine model. Although the canine model offers a number of advantages for evaluating potential therapies for GSDIa, there are also some significant challenges involved in its use. Despite these challenges, the canine model of GSDIa should continue to provide valuable information about the potential for generating curative therapies for GSDIa as well as other genetic hepatic diseases.

  20. Predominant role of gluconeogenesis in the hepatic glycogen repletion of diabetic rats.

    OpenAIRE

    Giaccari, A; Rossetti, L.

    1992-01-01

    Liver glycogen formation can occur via the direct (glucose----glucose-6-phosphate----glycogen) or indirect (glucose----C3 compounds----glucose-6-phosphate----glycogen) pathways. In the present study we have examined the effect of hyperglycemia on the pathways of hepatic glycogenesis, estimated from liver uridine diphosphoglucose (UDPglucose) specific activities, and on peripheral (muscle) glucose metabolism in awake, unstressed control and 90% pancreatectomized, diabetic rats. Under identical...

  1. FR258900, a potential anti-hyperglycemic drug, binds at the allosteric site of glycogen phosphorylase

    OpenAIRE

    Tiraidis, C.; Alexacou, K. M.; Zographos, Spyros E.; Leonidas, Demetres D.; Gimisis, T.; Oikonomakos, Nikos G.

    2007-01-01

    FR258900 has been discovered as a novel inhibitor of human liver glycogen phosphorylase a and proved to suppress hepatic glycogen breakdown and reduce plasma glucose concentrations in diabetic mice models. To elucidate the mechanism of inhibition, we have determined the crystal structure of the cocrystallized rabbit muscle glycogen phosphorylase b–FR258900 complex and refined it to 2.2 Å resolution. The structure demonstrates that the inhibitor binds at the allosteric activator site, where th...

  2. Creatine supplementation spares muscle glycogen during high intensity intermittent exercise in rats

    OpenAIRE

    Costa André; Marquezi Marcelo; Gualano Bruno; Roschel Hamilton; Lancha Antonio H

    2010-01-01

    Abstract Background The effects of creatine (CR) supplementation on glycogen content are still debatable. Thus, due to the current lack of clarity, we investigated the effects of CR supplementation on muscle glycogen content after high intensity intermittent exercise in rats. Methods First, the animals were submitted to a high intensity intermittent maximal swimming exercise protocol to ensure that CR-supplementation was able to delay fatigue (experiment 1). Then, the CR-mediated glycogen spa...

  3. Role of glycogen availability in sarcoplasmic reticulum Ca2+ kinetics in human skeletal muscle

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Nielsen, Joachim; Saltin, Bengt;

    2011-01-01

    Glucose is stored as glycogen in skeletal muscle. The importance of glycogen as a fuel during exercise has been recognized since the 1960s; however, little is known about the precise mechanism that relates skeletal muscle glycogen to muscle fatigue. We show that low muscle glycogen is associated ...... signal that links energy utilization, i.e. muscle contraction, with the energy content in the muscle, thereby inhibiting a detrimental depletion of the muscle energy store.......Glucose is stored as glycogen in skeletal muscle. The importance of glycogen as a fuel during exercise has been recognized since the 1960s; however, little is known about the precise mechanism that relates skeletal muscle glycogen to muscle fatigue. We show that low muscle glycogen is associated...... with an impairment of muscle ability to release Ca(2+), which is an important signal in the muscle activation. Thus, depletion of glycogen during prolonged, exhausting exercise may contribute to muscle fatigue by causing decreased Ca(2+) release inside the muscle. These data provide indications of a...

  4. Glycogen depletion and resynthesis during 14 days of chronic low-frequency stimulation of rabbit muscle.

    Science.gov (United States)

    Prats, C; Bernal, C; Cadefau, J A; Frias, J; Tibolla, M; Cussó, R

    2002-10-10

    Electro-stimulation alters muscle metabolism and the extent of this change depends on application intensity and duration. The effect of 14 days of chronic electro-stimulation on glycogen turnover and on the regulation of glycogen synthase in fast-twitch muscle was studied. The results showed that macro- and proglycogen degrade simultaneously during the first hour of stimulation. After 3 h, the muscle showed net synthesis, with an increase in the proglycogen fraction. The glycogen content peaked after 4 days of stimulation, macroglycogen being the predominant fraction at that time. Glycogen synthase was determined during electro-stimulation. The activity of this enzyme was measured at low UDPG concentration with either high or low Glu-6-P content. Western blots were performed against glycogen synthase over a range of stimulation periods. Activation of this enzyme was maximum before the net synthesis of glycogen, partial during net synthesis, and low during late synthesis. These observations suggest that the more active, dephosphorylated and very low phosphorylated forms of glycogen synthase may participate in the first steps of glycogen resynthesis before net synthesis is observed, while partially phosphorylated forms are most active during glycogen elongation. PMID:12383944

  5. Hepatic glycogen can regulate hypoglycemic counterregulation via a liver-brain axis.

    Science.gov (United States)

    Winnick, Jason J; Kraft, Guillaume; Gregory, Justin M; Edgerton, Dale S; Williams, Phillip; Hajizadeh, Ian A; Kamal, Maahum Z; Smith, Marta; Farmer, Ben; Scott, Melanie; Neal, Doss; Donahue, E Patrick; Allen, Eric; Cherrington, Alan D

    2016-06-01

    Liver glycogen is important for the counterregulation of hypoglycemia and is reduced in individuals with type 1 diabetes (T1D). Here, we examined the effect of varying hepatic glycogen content on the counterregulatory response to low blood sugar in dogs. During the first 4 hours of each study, hepatic glycogen was increased by augmenting hepatic glucose uptake using hyperglycemia and a low-dose intraportal fructose infusion. After hepatic glycogen levels were increased, animals underwent a 2-hour control period with no fructose infusion followed by a 2-hour hyperinsulinemic/hypoglycemic clamp. Compared with control treatment, fructose infusion caused a large increase in liver glycogen that markedly elevated the response of epinephrine and glucagon to a given hypoglycemia and increased net hepatic glucose output (NHGO). Moreover, prior denervation of the liver abolished the improved counterregulatory responses that resulted from increased liver glycogen content. When hepatic glycogen content was lowered, glucagon and NHGO responses to insulin-induced hypoglycemia were reduced. We conclude that there is a liver-brain counterregulatory axis that is responsive to liver glycogen content. It remains to be determined whether the risk of iatrogenic hypoglycemia in T1D humans could be lessened by targeting metabolic pathway(s) associated with hepatic glycogen repletion. PMID:27140398

  6. Glycogen content relative to expression of glycogen phosphorylase (GPH) and hexokinase (HK) during the reproductive cycle in the Fujian Oyster,Crassostrea angulata

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhen; NI Jianbin; KE Caihuan

    2015-01-01

    Glycogen, a polymer of glucose, is an important means of storing energy. It is degraded by glycogen phosphorylase (GPH) and hexokinase (HK), glycogen phosphorylase, and hexokinase cDNAs (Ca-GPH andCa-HK, respectively), which encode the primary enzymes involved in glycogen use, cloned and characterized and used to investigate the regulation of glycogen metabolism at the mRNA level inCrassostrea angulata. Their expression profiles were examined in different tissues and during different reproductive stages. Full-length cDNA ofGPH was 3 078 bp in length with a 2 607 bp open reading frame (ORF) predicted to encode a protein of 868 amino acids (aa). The full-lengthHK cDNA was 3 088 bp long, with an ORF of 1 433 bp, predicted to encode a protein of 505 aa. Expression levels of both genes were found to be significantly higher in the gonads and adductor muscle than in the mantle, gill, and visceral mass. They were especially high in the adductor muscle, which suggested that these oysters can use glycogen to produce a readily available supply of glucose to support adductor muscle activity. The regulation of both genes was also found to be correlated with glycogen content via qRT-PCR andin situ hybridization and was dependent upon the stage of the reproductive cycle (initiation, maturation, ripeness). In this way, it appears that the expression ofCa-GPH andCa-HK is driven by the reproductive cycle of the oyster, reflecting the central role played by glycogen in energy use and gametogenic development inC. angulata. It is here suggested thatCa-GPH andCa-HK can be used as useful molecular markers for identifying the stages of glycogen metabolism and reproduction inC. angulata.

  7. Compartmentation of glycogen metabolism revealed from 13C isotopologue distributions

    Directory of Open Access Journals (Sweden)

    Marin de Mas Igor

    2011-10-01

    Full Text Available Abstract Background Stable isotope tracers are used to assess metabolic flux profiles in living cells. The existing methods of measurement average out the isotopic isomer distribution in metabolites throughout the cell, whereas the knowledge of compartmental organization of analyzed pathways is crucial for the evaluation of true fluxes. That is why we accepted a challenge to create a software tool that allows deciphering the compartmentation of metabolites based on the analysis of average isotopic isomer distribution. Results The software Isodyn, which simulates the dynamics of isotopic isomer distribution in central metabolic pathways, was supplemented by algorithms facilitating the transition between various analyzed metabolic schemes, and by the tools for model discrimination. It simulated 13C isotope distributions in glucose, lactate, glutamate and glycogen, measured by mass spectrometry after incubation of hepatocytes in the presence of only labeled glucose or glucose and lactate together (with label either in glucose or lactate. The simulations assumed either a single intracellular hexose phosphate pool, or also channeling of hexose phosphates resulting in a different isotopic composition of glycogen. Model discrimination test was applied to check the consistency of both models with experimental data. Metabolic flux profiles, evaluated with the accepted model that assumes channeling, revealed the range of changes in metabolic fluxes in liver cells. Conclusions The analysis of compartmentation of metabolic networks based on the measured 13C distribution was included in Isodyn as a routine procedure. The advantage of this implementation is that, being a part of evaluation of metabolic fluxes, it does not require additional experiments to study metabolic compartmentation. The analysis of experimental data revealed that the distribution of measured 13C-labeled glucose metabolites is inconsistent with the idea of perfect mixing of hexose

  8. Effect of acute and recurrent hypoglycemia on changes in brain glycogen concentration.

    Science.gov (United States)

    Herzog, Raimund I; Chan, Owen; Yu, Sunkyung; Dziura, James; McNay, Ewan C; Sherwin, Robert S

    2008-04-01

    Our objective was to evaluate whether excessive brain glycogen deposition might follow episodes of acute hypoglycemia (AH) and thus play a role in the hypoglycemia-associated autonomic failure seen in diabetic patients receiving intensive insulin treatment. We determined brain glucose and glycogen recovery kinetics after AH and recurrent hypoglycemia (RH), an established animal model of counterregulatory failure. A single bout of insulin-induced AH or RH for 3 consecutive days was used to deplete brain glucose and glycogen stores in rats. After microwave fixation and glycogen extraction, regional recovery kinetics in the brain was determined using a biochemical assay. Both AH and RH treatments reduced glycogen levels in the cerebellum, cortex, and hypothalamus from control levels of 7.78 +/- 0.55, 5.4 +/- 0.38, and 4.45 +/- 0.37 micromol/g, respectively, to approximately 50% corresponding to a net glycogen utilization rate between 0.6 and 1.2 micromol/g.h. After hypoglycemia, glycogen levels returned to baseline within 6 h in both the AH and the RH group. However, recovery of brain glycogen tended to be faster in rats exposed to RH. This effect followed more rapid recovery of brain glucose levels in the RH group, despite similar blood glucose levels in both groups. There was no statistically significant increase above baseline glycogen levels in either group. In particular, brain glycogen was not increased 24 h after the last of recurrent episodes of hypoglycemia, when a significant counterregulatory defect could be documented during a hyperinsulinemic hypoglycemic clamp study. We conclude that glycogen supercompensation is not a major contributory factor to the pathogenesis of hypoglycemia-associated autonomic failure. PMID:18187548

  9. Brain glycogen – new perspectives on its metabolic function and regulation at the subcellular level

    Directory of Open Access Journals (Sweden)

    Linea Frimodt Obel

    2012-03-01

    Full Text Available Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g. liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia. In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies – it is a highly dynamic molecule with versatile implications in brain function, i.e. synaptic activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms underlying glycogen metabolism. Based on i the compartmentation of the interconnected second messenger pathways controlling glycogen metabolism (calcium and cAMP, ii alterations in the subcellular location of glycogen-associated enzymes and proteins induced by the metabolic status and iii a sequential component in the intermolecular mechanisms of glycogen metabolism, we suggest that glycogen metabolism in astrocytes is compartmentalized at the subcellular level. As a consequence, the meaning and importance of conventional terms used to describe glycogen metabolism (e.g. turnover is challenged. Overall, this review represents an overview of contemporary knowledge about brain glycogen and its metabolism and function. However, it also has a sharp focus on what we do not know, which is perhaps even more important for the future quest of uncovering the roles of glycogen in brain physiology and pathology.

  10. Enzymatic description of the anhydrofructose pathway of glycogen degradation. I

    DEFF Research Database (Denmark)

    Yu, Shukun; Refdahl, Charlotte; Lundt, Inge

    2004-01-01

    The anhydrofructose pathway describes the degradation of glycogen and starch to metabolites via 1,5-anhydro-D-fructose (1,5AnFru). The enzyme catalyzing the first reaction step of this pathway, i.e., a-1,4-glucan lyase (EC 4.2.1.13), has been purified, cloned and characterized from fungi and red...... algae in our laboratory earlier. In the present study, two 1,5AnFru metabolizing enzymes were discovered in the fungus Anthracobia melaloma for the formation of ascopyrone P (APP), a fungal secondary metabolite exhibiting antibacterial and antioxidant activity. These are 1,5AnFru dehydratase (AFDH) and...

  11. Biodegradable glycogen-based nanostructures for biomedicine application

    Czech Academy of Sciences Publication Activity Database

    Rabyk, Mariia; Pařízek, Martin; Hrubý, Martin; Vetrík, Miroslav; Kučka, Jan; Pospíšilová, Aneta; Štěpánek, Petr

    Budapest : Laboratory of Plastics and Rubber Technology, Budapest University of Technology and Economics, 2014, L-232. [International Conference on Bio-Based Polymers and Composites /2./ - BiPoCo 2014. Visegrád (HU), 24.08.2014-28.08.2014] R&D Projects: GA ČR GA202/09/2078; GA ČR GAP208/10/1600; GA MPO FR-TI4/625 Grant ostatní: AV ČR(CZ) M200501201 Institutional support: RVO:61389013 ; RVO:67985823 Keywords : nanoparticles * in vivo imaging * glycogen Subject RIV: CF - Physical ; Theoretical Chemistry; EI - Biotechnology ; Bionics (FGU-C)

  12. Glycogen as a biodegradable construction nanomaterial for in vivo use

    Czech Academy of Sciences Publication Activity Database

    Filippov, Sergey K.; Sedláček, Ondřej; Bogomolova, Anna; Vetrík, Miroslav; Jirák, D.; Kovář, J.; Kučka, Jan; Bals, S.; Turner, S.; Štěpánek, Petr; Hrubý, Martin

    2012-01-01

    Roč. 12, č. 12 (2012), s. 1731-1738. ISSN 1616-5187 R&D Projects: GA ČR GA202/09/2078; GA ČR GAP108/12/0640; GA ČR GAP208/10/1600; GA ČR GPP207/10/P054 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : nanoparticles * in vivo imaging * glycogen Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.742, year: 2012

  13. Cinnamon increases liver glycogen in an animal model of insulin resistance

    Science.gov (United States)

    Cinnamon, and aqueous polyphenol extracts of cinnamon, improve insulin sensitivity in vitro, and in animal and human studies. Given the relationship between the glucose/insulin system and glycogen metabolism, the objective of this study was to determine the effects of cinnamon on glycogen synthesis...

  14. Effect of transportation stress on hepatic glycogen of Oreochromis niloticus (L.)

    OpenAIRE

    Orji, R.C.A.

    1998-01-01

    Oreochromis niloticus was subjected to transportation stress to investigate hepatic glycogen levels and mortality as indices of stress. Mortalities lasted up to three days after transportation, except in highly aerated samples. Heptic glycogen levels in transported fish were significantly lower in the controls. Stress appeared to be more intense when fish were transported at a high density and in a high salinity medium.

  15. Glycogen depletion and resynthesis during 14 days of chronic low-frequency stimulation of rabbit muscle

    DEFF Research Database (Denmark)

    Prats, C; Bernal, C; Cadefau, J A;

    2002-01-01

    Electro-stimulation alters muscle metabolism and the extent of this change depends on application intensity and duration. The effect of 14 days of chronic electro-stimulation on glycogen turnover and on the regulation of glycogen synthase in fast-twitch muscle was studied. The results showed that...

  16. Brain glycogen supercompensation in the mouse after recovery from insulin-induced hypoglycemia.

    Science.gov (United States)

    Canada, Sarah E; Weaver, Staci A; Sharpe, Shannon N; Pederson, Bartholomew A

    2011-04-01

    Brain glycogen is proposed to function under both physiological and pathological conditions. Pharmacological elevation of this glucose polymer in brain is hypothesized to protect neurons against hypoglycemia-induced cell death. Elevation of brain glycogen levels due to prior hypoglycemia is postulated to contribute to the development of hypoglycemia-associated autonomic failure (HAAF) in insulin-treated diabetic patients. This latter mode of elevating glycogen levels is termed "supercompensation." We tested whether brain glycogen supercompensation occurs in healthy, conscious mice after recovery from insulin-induced acute or recurrent hypoglycemia. Blood glucose levels were lowered to less than 2.2 mmol/liter for 90 min by administration of insulin. Brain glucose levels decreased at least 80% and brain glycogen levels decreased approximately 50% after episodes of either acute or recurrent hypoglycemia. After these hypoglycemic episodes, mice were allowed access to food for 6 or 27 hr. After 6 hr, blood and brain glucose levels were restored but brain glycogen levels were elevated by 25% in mice that had been subjected to either acute or recurrent hypoglycemia compared with saline-treated controls. After a 27-hr recovery period, the concentration of brain glycogen had returned to baseline levels in mice previously subjected to either acute or recurrent hypoglycemia. We conclude that brain glycogen supercompensation occurs in healthy mice, but its functional significance remains to be established. PMID:21259334

  17. Glycogen storage disease type I: clinical and laboratory profile

    Directory of Open Access Journals (Sweden)

    Berenice L. Santos

    2014-12-01

    Full Text Available OBJECTIVES: To characterize the clinical, laboratory, and anthropometric profile of a sample of Brazilian patients with glycogen storage disease type I managed at an outpatient referral clinic for inborn errors of metabolism. METHODS: This was a cross-sectional outpatient study based on a convenience sampling strategy. Data on diagnosis, management, anthropometric parameters, and follow-up were assessed. RESULTS: Twenty-one patients were included (median age 10 years, range 1-25 years, all using uncooked cornstarch therapy. Median age at diagnosis was 7 months (range, 1-132 months, and 19 patients underwent liver biopsy for diagnostic confirmation. Overweight, short stature, hepatomegaly, and liver nodules were present in 16 of 21, four of 21, nine of 14, and three of 14 patients, respectively. A correlation was found between height-for-age and BMI-for-age Z-scores (r = 0.561; p = 0.008. CONCLUSIONS: Diagnosis of glycogen storage disease type I is delayed in Brazil. Most patients undergo liver biopsy for diagnostic confirmation, even though the combination of a characteristic clinical presentation and molecular methods can provide a definitive diagnosis in a less invasive manner. Obesity is a side effect of cornstarch therapy, and appears to be associated with growth in these patients.

  18. Interleukin 6 stimulates hepatic glucose release from prelabeled glycogen pools

    International Nuclear Information System (INIS)

    Cytokines, derived from a wide variety of cell types, are now believed to initiate many of the physiological responses accompanying the inflammatory phase that follows either Gram-negative septicemia or thermal injury. Because hypoglycemia (after endotoxic challenge) and hyperglycemia (after thermal injury) represent well-characterized responses to these injuries, we sought to determine whether hepatic glycogen metabolism could be altered by specific cytokines. Cultured adult rat hepatocytes were prelabeled with [14C]glucose for 24 h, a procedure that resulted in the labeling of hepatic glycogen pools that subsequently could be depleted (with concomitant [14C]glucose release) by either glucagon or norepinephrine. After the addition of a highly concentrated human monocyte-conditioned medium (MCM) or various cytokines to these prelabeled cells, [14C]glucose release was stimulated by MCM and recombinant human interleukin 6 (IL-6) but was not stimulated by other cytokines tested. Furthermore, only antisera to IL-6 were capable of reducing the glucose-releasing factor activity found in MCM. These data therefore suggest a novel glucoregulatory role for IL-6

  19. Interleukin 6 stimulates hepatic glucose release from prelabeled glycogen pools

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, D.G. (Shriners Burns Institute, Galveston, TX (USA))

    1990-01-01

    Cytokines, derived from a wide variety of cell types, are now believed to initiate many of the physiological responses accompanying the inflammatory phase that follows either Gram-negative septicemia or thermal injury. Because hypoglycemia (after endotoxic challenge) and hyperglycemia (after thermal injury) represent well-characterized responses to these injuries, we sought to determine whether hepatic glycogen metabolism could be altered by specific cytokines. Cultured adult rat hepatocytes were prelabeled with ({sup 14}C)glucose for 24 h, a procedure that resulted in the labeling of hepatic glycogen pools that subsequently could be depleted (with concomitant ({sup 14}C)glucose release) by either glucagon or norepinephrine. After the addition of a highly concentrated human monocyte-conditioned medium (MCM) or various cytokines to these prelabeled cells, ({sup 14}C)glucose release was stimulated by MCM and recombinant human interleukin 6 (IL-6) but was not stimulated by other cytokines tested. Furthermore, only antisera to IL-6 were capable of reducing the glucose-releasing factor activity found in MCM. These data therefore suggest a novel glucoregulatory role for IL-6.

  20. Insulin resistance is associated with reduced fasting and insulin-stimulated glycogen synthase phosphatase activity in human skeletal muscle.

    OpenAIRE

    Kida, Y; Esposito-Del Puente, A; Bogardus, C; Mott, D M

    1990-01-01

    Insulin-stimulated glycogen synthase activity in human skeletal muscle correlates with insulin-mediated glucose disposal rate (M) and is reduced in insulin-resistant subjects. We have previously reported reduced insulin-stimulated glycogen synthase activity associated with reduced fasting glycogen synthase phosphatase activity in skeletal muscle of insulin-resistant Pima Indians. In this study we investigated the time course for insulin stimulation of glycogen synthase and synthase phosphatas...

  1. Increases in glycogenin and glycogenin mRNA accompany glycogen resynthesis in human skeletal muscle

    DEFF Research Database (Denmark)

    Shearer, Jane; Wilson, Rhonda J.; Battram, Danielle S.;

    2005-01-01

    300 min postexercise. Together, these results show that, during recovery from prolonged exhaustive exercise, glycogenin mRNA and protein content and activity increase in muscle. This may facilitate rapid glycogen resynthesis by providing the glycogenin backbone of proglycogen, the major component of......Glycogenin is the self-glycosylating protein primer that initiates glycogen granule formation. To examine the role of this protein during glycogen resynthesis, eight male subjects exercised to exhaustion on a cycle ergometer at 75% VO2 max followed by five 30-s sprints at maximal capacity to...... further deplete glycogen stores. During recovery, carbohydrate (75 g/h) was supplied to promote rapid glycogen repletion, and muscle biopsies were obtained from the vastus lateralis at 0, 30, 120, and 300 min postexercise. At time 0, no free (deglycosylated) glycogenin was detected in muscle, indicating...

  2. [Role of glucocorticoids in the regulation of postexercise glycogen replenishment, and the mechanism of their action].

    Science.gov (United States)

    Kyrge, P K; Eller, A K; Timpmann, S K; Séppet, E K

    1982-10-01

    Repeated determination of post--exercise glycogen repletion in liver, heart, white and red skeletal muscles of intact and adrenalectomized rats with or without the administration of dexamethasone and sucrose revealed that a glycogen supercompensation effect depends on the availability of glucocorticoids. Other factors which considerably modify the effect of glucocorticoids on glycogen synthesis, are the molecular properties of the mechanism through which the hormone actualizes its biological effect. The stimulating effect of dexamethasone on glycogen synthesis in the liver and heart muscle of adrenalectomized rats is blocked by cycloheximide. This suggests that the role of glucocorticoids in the regulation of post--exercise glycogen synthesis depends upon cycloheximide--sensitive protein synthesis. PMID:7173428

  3. Metabolic responses to adrenaline and muscle glycogen content in dogs treated with thyroxine.

    Science.gov (United States)

    Brzezińska, Z; Kaciuba-Uściłko, H

    1978-01-01

    Lipolytic, hyperglycaemic and lactacidaemic responses to 1h adrenaline infusion (0.1 microgram/kg/min) were compared in resting dogs before (control) and after prolonged thyroxine (T4) treatment. Besides, the effect of 2-week thyroxine administration on muscle glycogen content, and its changes following adrenaline infusion were examined. Prolonged T4-treatment of dogs resulted in considerable alterations of the metabolic actions of adrenaline. A marked difference between the control and T4-treated dogs was also found in the muscle glycogen content, which was significantly lower in the latter. Both in the control and T4-injected dogs adrenaline infusion caused similar depletion of the muscle glycogen store. However, in all the control animals examined supercompensation of muscle glycogen was noted 1 h following termination of adrenaline infusion, whereas T4-treated dogs were unable of incurring any significant muscle glycogen deposition. PMID:742367

  4. The nutritional status of Methanosarcina acetivorans regulates glycogen metabolism and gluconeogenesis and glycolysis fluxes.

    Science.gov (United States)

    Santiago-Martínez, Michel Geovanni; Encalada, Rusely; Lira-Silva, Elizabeth; Pineda, Erika; Gallardo-Pérez, Juan Carlos; Reyes-García, Marco Antonio; Saavedra, Emma; Moreno-Sánchez, Rafael; Marín-Hernández, Alvaro; Jasso-Chávez, Ricardo

    2016-05-01

    Gluconeogenesis is an essential pathway in methanogens because they are unable to use exogenous hexoses as carbon source for cell growth. With the aim of understanding the regulatory mechanisms of central carbon metabolism in Methanosarcina acetivorans, the present study investigated gene expression, the activities and metabolic regulation of key enzymes, metabolite contents and fluxes of gluconeogenesis, as well as glycolysis and glycogen synthesis/degradation pathways. Cells were grown with methanol as a carbon source. Key enzymes were kinetically characterized at physiological pH/temperature. Active consumption of methanol during exponential cell growth correlated with significant methanogenesis, gluconeogenic flux and steady glycogen synthesis. After methanol exhaustion, cells reached the stationary growth phase, which correlated with the rise in glycogen consumption and glycolytic flux, decreased methanogenesis, negligible acetate production and an absence of gluconeogenesis. Elevated activities of carbon monoxide dehydrogenase/acetyl-CoA synthetase complex and pyruvate: ferredoxin oxidoreductase suggested the generation of acetyl-CoA and pyruvate for glycogen synthesis. In the early stationary growth phase, the transcript contents and activities of pyruvate phosphate dikinase, fructose 1,6-bisphosphatase and glycogen synthase decreased, whereas those of glycogen phosphorylase, ADP-phosphofructokinase and pyruvate kinase increased. Therefore, glycogen and gluconeogenic metabolites were synthesized when an external carbon source was provided. Once such a carbon source became depleted, glycolysis and methanogenesis fed by glycogen degradation provided the ATP supply. Weak inhibition of key enzymes by metabolites suggested that the pathways evaluated were mainly transcriptionally regulated. Because glycogen metabolism and glycolysis/gluconeogenesis are not present in all methanogens, the overall data suggest that glycogen storage might represent an environmental

  5. Rumen papillae keratinization, cell glycogen and chemical composition of the meat from young bulls fed different levels of concentrate and babassu mesocarp bran

    Directory of Open Access Journals (Sweden)

    Simone Santos Barros

    2015-06-01

    Full Text Available This study aimed to assess the rumen papillae keratinization, cellular levels of liver and muscle glycogen, and the chemical composition of meat from feedlot-finished Nellore young bulls fed with levels of concentrate and babassu mesocarp bran. Twenty-eight animals with initial age of 21 months and initial body weight of 356.7 ± 19 kg were randomized to the following treatments: two levels of concentrate in the diet (65% and 71%, with or without inclusion of 35% of babassu mesocarp bran. Fragments of liver, muscle and rumen were obtained after slaughter of the animals. Levels of concentrate and babassu mesocarp bran in the diet did not affect the quantities of liver and muscle glycogen, and did not induce hyperkeratinization of rumen papillae. The chemical composition of the meat was not affected by the studied factors. The inclusion of 35% babassu mesocarp bran in high concentrate diets does not induce hyperkeratinization of rumen papillae, and does not change the amount of muscle and liver glycogen or the chemical characteristics of meat of Nellore young bulls.

  6. Glycogen Synthase Kinase-3 regulates multiple myeloma cell growth and bortezomib-induced cell death

    Directory of Open Access Journals (Sweden)

    Colpo Anna

    2010-10-01

    Full Text Available Abstract Background Glycogen Synthase Kinase-3 (GSK-3 α and β are two serine-threonine kinases controlling insulin, Wnt/β-catenin, NF-κB signaling and other cancer-associated transduction pathways. Recent evidence suggests that GSK-3 could function as growth-promoting kinases, especially in malignant cells. In this study, we have investigated GSK-3α and GSK-3β function in multiple myeloma (MM. Methods GSK-3 α and β expression and cellular localization were investigated by Western blot (WB and immunofluorescence analysis in a panel of MM cell lines and in freshly isolated plasma cells from patients. MM cell growth, viability and sensitivity to bortezomib was assessed upon treatment with GSK-3 specific inhibitors or transfection with siRNAs against GSK-3 α and β isoforms. Survival signaling pathways were studied with WB analysis. Results GSK-3α and GSK-3β were differently expressed and phosphorylated in MM cells. Inhibition of GSK-3 with the ATP-competitive, small chemical compounds SB216763 and SB415286 caused MM cell growth arrest and apoptosis through the activation of the intrinsic pathway. Importantly, the two inhibitors augmented the bortezomib-induced MM cell cytotoxicity. RNA interference experiments showed that the two GSK-3 isoforms have distinct roles: GSK-3β knock down decreased MM cell viability, while GSK-3α knock down was associated with a higher rate of bortezomib-induced cytotoxicity. GSK-3 inhibition caused accumulation of β-catenin and nuclear phospho-ERK1, 2. Moreover, GSK-3 inhibition and GSK-3α knockdown enhanced bortezomib-induced AKT and MCL-1 protein degradation. Interestingly, bortezomib caused a reduction of GSK-3 serine phosphorylation and its nuclear accumulation with a mechanism that resulted partly dependent on GSK-3 itself. Conclusions These data suggest that in MM cells GSK-3α and β i play distinct roles in cell survival and ii modulate the sensitivity to proteasome inhibitors.

  7. Glycogen Synthase Kinase-3 regulates multiple myeloma cell growth and bortezomib-induced cell death

    International Nuclear Information System (INIS)

    Glycogen Synthase Kinase-3 (GSK-3) α and β are two serine-threonine kinases controlling insulin, Wnt/β-catenin, NF-κB signaling and other cancer-associated transduction pathways. Recent evidence suggests that GSK-3 could function as growth-promoting kinases, especially in malignant cells. In this study, we have investigated GSK-3α and GSK-3β function in multiple myeloma (MM). GSK-3 α and β expression and cellular localization were investigated by Western blot (WB) and immunofluorescence analysis in a panel of MM cell lines and in freshly isolated plasma cells from patients. MM cell growth, viability and sensitivity to bortezomib was assessed upon treatment with GSK-3 specific inhibitors or transfection with siRNAs against GSK-3 α and β isoforms. Survival signaling pathways were studied with WB analysis. GSK-3α and GSK-3β were differently expressed and phosphorylated in MM cells. Inhibition of GSK-3 with the ATP-competitive, small chemical compounds SB216763 and SB415286 caused MM cell growth arrest and apoptosis through the activation of the intrinsic pathway. Importantly, the two inhibitors augmented the bortezomib-induced MM cell cytotoxicity. RNA interference experiments showed that the two GSK-3 isoforms have distinct roles: GSK-3β knock down decreased MM cell viability, while GSK-3α knock down was associated with a higher rate of bortezomib-induced cytotoxicity. GSK-3 inhibition caused accumulation of β-catenin and nuclear phospho-ERK1, 2. Moreover, GSK-3 inhibition and GSK-3α knockdown enhanced bortezomib-induced AKT and MCL-1 protein degradation. Interestingly, bortezomib caused a reduction of GSK-3 serine phosphorylation and its nuclear accumulation with a mechanism that resulted partly dependent on GSK-3 itself. These data suggest that in MM cells GSK-3α and β i) play distinct roles in cell survival and ii) modulate the sensitivity to proteasome inhibitors

  8. Insulin-independent glycogen supercompensation in isolated mouse skeletal muscle: role of phosphorylase inactivation.

    Science.gov (United States)

    Sandström, Marie E; Abbate, Fabio; Andersson, Daniel C; Zhang, Shi-Jin; Westerblad, Håkan; Katz, Abram

    2004-08-01

    Glycogen supercompensation (increase in muscle glycogen content above basal) is an established phenomenon induced by unknown mechanisms. It consists of both insulin-dependent and -independent components. Here, we investigate insulin-independent glycogen supercompensation in isolated, intact extensor digitorum longus muscles from mice. Muscles were stimulated electrically, incubated in vitro with 5.5 mM glucose for up to 16 h and then analysed for glycogen, glucose uptake and enzyme activities. Basal glycogen was 84+/-6 micro mol glucosyl units/g dry muscle and was depleted by 80% after 10 min contraction. Glycogen increased after contraction, reaching a peak value of 113+/-9 micro mol glucosyl units/g dry muscle ( Psupercompensation (4-6 h). Phosphorylase fractional activity (+/-adenosine monophosphate; directly related to phosphorylation state of the enzyme) decreased to 60% of basal after contraction and decreased further during the initial 4 h of recovery to 40% of basal ( Psupercompensation involves inactivation of phosphorylase and hence an inhibition of glycogen breakdown. PMID:15085341

  9. Technical note: A method for isolating glycogen granules from ruminal protozoa for further characterization.

    Science.gov (United States)

    Hall, Mary Beth

    2016-03-01

    Evaluation of physical, chemical, and enzymatic hydrolysis characteristics of protozoal glycogen is best performed on a pure substrate to avoid interference from other cell components. A method for isolating protozoal glycogen granules without use of detergents or other potentially contaminating chemicals was developed. Rumen inoculum was incubated anerobically in vitro with glucose. Glycogen-laden protozoa produced in the fermentation, primarily isotrichids, were allowed to sediment in a separatory funnel and were dispensed. The protozoa were processed through repeated centrifugations and sonication to isolate glycogen granules largely free of feed and cellular debris. The final water-insoluble lyophilized product analyzed as 98.3% α-glucan with very rare starch granules and 1.9% protein. Observed losses of glycogen granules during the clean-up process indicate that this procedure should not be used for quantitative assessment of protozoal glycogen from fermentations. Further optimization of this procedure to enhance the amount of glycogen obtained per fermentation may be possible. PMID:26805977

  10. Carbohydrate supercompensation and muscle glycogen utilization during exhaustive running in highly trained athletes.

    Science.gov (United States)

    Madsen, K; Pedersen, P K; Rose, P; Richter, E A

    1990-01-01

    Three female and three male highly trained endurance runners with mean maximal oxygen uptake (VO2max) values of 60.5 and 71.5 ml.kg-1.min-1, respectively, ran to exhaustion at 75%-80% of VO2max on two occasions after an overnight fast. One experiment was performed after a normal diet and training regimen (Norm), the other after a diet and training programme intended to increase muscle glycogen levels (Carb). Muscle glycogen concentration in the gastrocnemius muscle increased by 25% (P less than 0.05) from 581 mmol.kg-1 dry weight, SEM 50 to 722 mmol.kg-1 dry weight, SEM 34 after Carb. Running time to exhaustion, however, was not significantly different in Carb and Norm, 77 min, SEM 13 vs 70 min, SEM 8, respectively. The average glycogen concentration following exhaustive running was 553 mmol.kg-1 dry weight, SEM 70 in Carb and 434 mmol.kg-1 dry weight, SEM 57 in Norm, indicating that in both tests muscle glycogen stores were decreased by about 25%. Periodic acid-Schiff staining for semi-quantitative glycogen determination in individual fibres confirmed that none of the fibres appeared to be glycogen-empty after exhaustive running. The steady-state respiratory exchange ratio was higher in Carb than in Norm (0.92, SEM 0.01 vs 0.89, SEM 0.01; P less than 0.05). Since muscle glycogen utilization was identical in the two tests, the indication of higher utilization of total carbohydrate appears to be related to a higher utilization of liver glycogen. We have concluded that glycogen depletion of the gastrocnemius muscle is unlikely to be the cause of fatigue during exhaustive running at 75%-80% of VO2max in highly trained endurance runners. Furthermore, diet- and training-induced carbohydrate super-compensation does not appear to improve endurance capacity in such individuals. PMID:2079068

  11. Postexercise glucose uptake and glycogen synthesis in skeletal muscle from GLUT4-deficient mice.

    Science.gov (United States)

    Ryder, J W; Kawano, Y; Galuska, D; Fahlman, R; Wallberg-Henriksson, H; Charron, M J; Zierath, J R

    1999-12-01

    To determine the role of GLUT4 on postexercise glucose transport and glycogen resynthesis in skeletal muscle, GLUT4-deficient and wild-type mice were studied after a 3 h swim exercise. In wild-type mice, insulin and swimming each increased 2-deoxyglucose uptake by twofold in extensor digitorum longus muscle. In contrast, insulin did not increase 2-deoxyglucose glucose uptake in muscle from GLUT4-null mice. Swimming increased glucose transport twofold in muscle from fed GLUT4-null mice, with no effect noted in fasted GLUT4-null mice. This exercise-associated 2-deoxyglucose glucose uptake was not accompanied by increased cell surface GLUT1 content. Glucose transport in GLUT4-null muscle was increased 1.6-fold over basal levels after electrical stimulation. Contraction-induced glucose transport activity was fourfold greater in wild-type vs. GLUT4-null muscle. Glycogen content in gastrocnemius muscle was similar between wild-type and GLUT4-null mice and was reduced approximately 50% after exercise. After 5 h carbohydrate refeeding, muscle glycogen content was fully restored in wild-type, with no change in GLUT4-null mice. After 24 h carbohydrate refeeding, muscle glycogen in GLUT4-null mice was restored to fed levels. In conclusion, GLUT4 is the major transporter responsible for exercise-induced glucose transport. Also, postexercise glycogen resynthesis in muscle was greatly delayed; unlike wild-type mice, glycogen supercompensation was not found. GLUT4 it is not essential for glycogen repletion since muscle glycogen levels in previously exercised GLUT4-null mice were totally restored after 24 h carbohydrate refeeding.-Ryder, J. W., Kawano, Y., Galuska, D., Fahlman, R., Wallberg-Henriksson, H., Charron, M. J., Zierath, J. R. Postexercise glucose uptake and glycogen synthesis in skeletal muscle from GLUT4-deficient mice. PMID:10593872

  12. Protection against cardiac anoxia--role and limitations of increased glycogen reserves in the isolated rat right ventricular strip.

    Science.gov (United States)

    Towart, R; Schlossmann, K; Kazda, S

    1981-01-01

    The effects of drugs on rat cardiac glycogen reserves in vivo, and on the subsequent in vitro sensitivity of the right ventricular strip preparation to anoxia have been investigated. Isoproterenol (0.2 mg/kg i.p.) causes immediate cardiac stimulation and reduction of glycogen reserves, coupled with an increased susceptibility to anoxia. Several hours after administration, glycogen levels are found to be greatly (100-200%) increased, by a "supercompensation" mechanism, and a marked tolerance to anoxia can be simultaneously demonstrated. In contrast, large doses of corticosteroids (dexamethasone, 8 mg/kg i.m.) increase glycogen levels without initial stimulation and glycogen depletion; increased myocardial tolerance to anoxia parallels the increase in glycogen reserves in vivo. We conclude that the myocardial tolerance to anoxia in this model is related to increased glycogen reserves, which increase the rate and/or duration of anaerobic glycolysis during anoxia. PMID:7332516

  13. Effect of in ovo feeding and its interaction with timing of first feed on glycogen reserves, muscle growth, and body weight.

    Science.gov (United States)

    Kornasio, R; Halevy, O; Kedar, O; Uni, Z

    2011-07-01

    Chicks are commonly fasted for the first 36 to 72 h posthatch because of the logistics of commercial production. Fasting for 48 to 72 h posthatch results in retarded BW, delayed intestinal development, and lower pectoral muscle weight. This study is focused on the first 36 h of fasting and its interaction with feeding before hatch. Four treatment groups, differing in time of first feed, 6 h [early feeding (EF)] or 36 h [standard feeding procedure (SP)] posthatch, with or without in ovo feeding (IOF) with dextrin and β-hydroxy-β-methylbutyrate-calcium salt in a saline solution, were examined for glycogen status in the liver and pectoral muscle, myogenic cell proliferation, and myofiber diameter in embryos and chickens on various days posthatch. In addition, chicken BW, ADG, pectoral muscle weight, and pectoral muscle percentage of BW until 35 d of age were recorded. Results showed that delaying the first feed for 36 h posthatch (SP group) led to an irreversibly reduced growth rate compared with the EF group. However, IOF affected the growth of chickens in the SP group, whereas the control embryos had depleted glycogen reserves in the liver; IOF-treated embryos had elevated hepatic glycogen contents on embryonic day (E) 19, E20, and the day of hatch. In addition, on d 2 posthatch, although hatchlings in the SP group showed the predicted low levels of glycogen in their livers, birds in the EF group exhibited more than 30-fold and 3-fold increases in liver and muscle glycogen, respectively. In ovo-fed birds in the SP group also exhibited higher glycogen reserves, BW, pectoral muscle weight, and BW gain than control birds in the SP group. In ovo feeding had an immediate effect on promoting myoblast proliferation on E19, whereas on d 3 posthatch, the effect was pronounced only in the EF groups. On d 5, although myoblast proliferation in all groups declined, it remained higher in both IOF groups. These effects were expressed on d 3 and 35 by myofiber diameter. Together

  14. Dual regulation of muscle glycogen synthase during exercise by activation and compartmentalization

    DEFF Research Database (Denmark)

    Prats, Clara; Helge, Jørn W; Nordby, Pernille; Qvortrup, Klaus; Ploug, Thorkil; Dela, Flemming; Wojtaszewski, Jørgen

    2009-01-01

    dephosphorylation at sites 2+2a, 3a, and 3a + 3b. Furthermore, we report the existence of several glycogen metabolism regulatory mechanisms based on GS intracellular compartmentalization. After exhausting exercise, epinephrine-induced protein kinase A activation leads to GS site 1b phosphorylation targeting the...... lateralis muscle of the previously reported mechanism of glycogen metabolism regulation in rabbit tibialis anterior muscle. After overnight low muscle glycogen level and/or in response to exhausting exercise-induced glycogenolysis, GS is associated with spherical structures at the I-band of sarcomeres....

  15. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. PMID:26233656

  16. Physiological aspects of the subcellular localization of glycogen in skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Ørtenblad, Niels

    2013-01-01

    and fatigability. Based on all these data, the available literature strongly indicates that the subcellular localization of glycogen has to be taken into consideration to fully understand and appreciate the role and regulation of glycogen metabolism and signaling in skeletal muscle. A full......Glucose is stored in skeletal muscle fibers as glycogen, a branched-chain polymer observed in electron microscopy images as roughly spherical particles (known as β-particles of 10-45 nm in diameter), which are distributed in distinct localizations within the myofibers and are physically associated...... with metabolic and scaffolding proteins. Although the subcellular localization of glycogen has been recognized for more than 40 years, the physiological role of the distinct localizations has received sparse attention. Recently, however, studies involving stereological, unbiased, quantitative methods...

  17. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  18. Adiponectin levels correlate with the severity of hypertriglyceridaemia in glycogen storage disease Ia

    NARCIS (Netherlands)

    Bandsma, R. H. J.; Smit, G. P. A.; Reijngoud, D. -J.; Kuipers, F.

    2009-01-01

    Glycogen storage disease type Ia (GSD Ia) is characterized by severe hypercholesterolaemia and hypertriglyceridaemia. Little is known about the aetiology of the hyperlipidaemia in GSD Ia. Adipokines play an important regulatory role in lipid metabolism. We investigated whether adipokine concentratio

  19. Isoform-selective regulation of glycogen phosphorylase by energy deprivation and phosphorylation in astrocytes

    DEFF Research Database (Denmark)

    Müller, Margit S; Pedersen, Sofie E; Walls, Anne B;

    2015-01-01

    Glycogen phosphorylase (GP) is activated to degrade glycogen in response to different stimuli, to support both the astrocyte's own metabolic demand and the metabolic needs of neurons. The regulatory mechanism allowing such a glycogenolytic response to distinct triggers remains incompletely...... understood. In the present study, we used siRNA-mediated differential knockdown of the two isoforms of GP expressed in astrocytes, muscle isoform (GPMM), and brain isoform (GPBB), to analyze isoform-specific regulatory characteristics in a cellular setting. Subsequently, we tested the response of each...... determination of glycogen content showing an increase in glycogen levels following knockdown of either GPMM or GPBB. NE triggered glycogenolysis within 15 min in control cells and after GPBB knockdown. However, astrocytes in which expression of GPMM had been silenced showed a delay in response to NE, with...

  20. When phosphorylated at Thr148, the β2-subunit of AMP-activated kinase does not associate with glycogen in skeletal muscle.

    Science.gov (United States)

    Xu, Hongyang; Frankenberg, Noni T; Lamb, Graham D; Gooley, Paul R; Stapleton, David I; Murphy, Robyn M

    2016-07-01

    The 5'-AMP-activated protein kinase (AMPK), a heterotrimeric complex that functions as an intracellular fuel sensor that affects metabolism, is activated in skeletal muscle in response to exercise and utilization of stored energy. The diffusibility properties of α- and β-AMPK were examined in isolated skeletal muscle fiber segments dissected from rat fast-twitch extensor digitorum longus and oxidative soleus muscles from which the surface membranes were removed by mechanical dissection. After the muscle segments were washed for 1 and 10 min, ∼60% and 75%, respectively, of the total AMPK pools were found in the diffusible fraction. After in vitro stimulation of the muscle, which resulted in an ∼80% decline in maximal force, 20% of the diffusible pool became bound in the fiber. This bound pool was not associated with glycogen, as determined by addition of a wash step containing amylase. Stimulation of extensor digitorum longus muscles resulted in 28% glycogen utilization and a 40% increase in phosphorylation of the downstream AMPK target acetyl carboxylase-CoA. This, however, had no effect on the proportion of total β2-AMPK that was phosphorylated in whole muscle homogenates measured by immunoprecipitation. These findings suggest that, in rat skeletal muscle, β2-AMPK is not associated with glycogen and that activation of AMPK by muscle contraction does not dephosphorylate β2-AMPK. These findings question the physiological relevance of the carbohydrate-binding function of β2-AMPK in skeletal muscle. PMID:27099349

  1. Stimulation of glycogen synthesis and lipogenesis by glutamine in isolated rat hepatocytes.

    OpenAIRE

    Lavoinne, A; Baquet, A.; Hue, Louis

    1987-01-01

    Glutamine stimulated glycogen synthesis and lactate production in hepatocytes from overnight-fasted normal and diabetic rats. The effect, which was half-maximal with about 3 mM-glutamine, depended on glucose concentration and was maximal below 10 mM-glucose. beta-2-Aminobicyclo[2.2.1.]heptane-2-carboxylic acid, an analogue of leucine, stimulated glutaminase flux, but inhibited the stimulation of glycogen synthesis by glutamine. Various purine analogues and inhibitors of purine synthesis were ...

  2. Glycogen overload by postexercise insulin administration abolished the exercise-induced increase in GLUT4 protein.

    Science.gov (United States)

    Chou, Chia-Hau; Tsai, Yin-Lan; Hou, Chien-Wen; Lee, Hsing-Hao; Chang, Wei-Hsiang; Lin, Tzi-Wen; Hsu, Tung-Hsiung; Huang, Yi-Jen; Kuo, Chia-Hua

    2005-12-01

    To elucidate the role of muscle glycogen storage on regulation of GLUT4 protein expression and whole-body glucose tolerance, muscle glycogen level was manipulated by exercise and insulin administration. Sixty Sprague-Dawley rats were evenly separated into three groups: control (CON), immediately after exercise (EX0), and 16 h after exercise (EX16). Rats from each group were further divided into two groups: saline- and insulin-injected. The 2-day exercise protocol consisted of 2 bouts of 3-h swimming with 45-min rest for each day, which effectively depleted glycogen in both red gastrocnemius (RG) and plantaris muscles. EX0 rats were sacrificed immediately after the last bout of exercise on second day. CON and EX16 rats were intubated with 1 g/kg glucose solution following exercise and recovery for 16 h before muscle tissue collection. Insulin (0.5 microU/kg) or saline was injected daily at the time when glucose was intubated. Insulin injection elevated muscle glycogen levels substantially in both muscles above saline-injected group at CON and EX16. With previous day insulin injection, EX0 preserved greater amount of postexercise glycogen above their saline-injected control. In the saline-injected rats, EX16 significantly increased GLUT4 protein level above CON, concurrent with muscle glycogen supercompensation. Insulin injection for EX16 rats significantly enhanced muscle glycogen level above their saline-injected control, but the increases in muscle GLUT4 protein and whole-body glucose tolerance were attenuated. In conclusion, the new finding of the study was that glycogen overload by postexercise insulin administration significantly abolished the exercise-induced increases in GLUT4 protein and glucose tolerance. PMID:16319996

  3. Seasonal changes in hepatocytic lipid droplets, glycogen deposits, and rough endoplasmic reticulum along the natural breeding cycle of female ohrid trout (Salmo letnica Kar.)-A semiquantitative ultrastructural study.

    Science.gov (United States)

    Jordanova, Maja; Rebok, Katerina; Malhão, Fernanda; Rocha, Maria J; Rocha, Eduardo

    2016-08-01

    This study on wild female Ohrid trout was primarily designed to provide a general overview of the breeding cycle influence upon selected aspects of hepatocytes. According with a semiquantitatively evaluation, some of these cell's structural compartments change during the breeding cycle. Structural modifications were disclosed in the relative occurrence of lipid, glycogen, and RER content during breeding cycle. The relative amount of lipid deposits in the hepatocytes was much greater in previtellogenesis, and decreased postspawning. So, while the seasonal changes in RER were positively related with the ovary maturation status, those of the lipid droplets followed an opposite trend. The hepatocytic glycogen occurred rarely, mainly in late-vitellogenesis and spawning, suggesting that in this species such kind of energy storage is comparatively unimportant. Lipid accumulation and later usage is, probably, the relevant biochemical pathway for Ohrid trout in the wild. While glycogen and RER contents were positively correlated with the gonadosomatic index, lipids were negatively correlated. Additionally, glycogen inclusions were positively correlated with the plasma estradiol levels. When comparing seasonal patterns from wild Ohrid trout with those from well-studied rainbow and brown trout (specimens studied were from aquaculture), there are contradicting results as to lipid and glycogen reserves, and also as to RER loads. The differences among the mentioned trout can result from intrinsic interspecies differences or may be associated with natural feeding conditions versus feeding with commercially prepared diets, or other factors. This study offers new data useful as standard to access liver pathology in wild and aquacultured Ohrid trout. Microsc. Res. Tech. 79:700-706, 2016. © 2016 Wiley Periodicals, Inc. PMID:27223583

  4. Brain glycogen supercompensation after different conditions of induced hypoglycemia and sustained swimming in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Blanco, A M; Gómez-Boronat, M; Pérez-Maceira, J; Mancebo, M J; Aldegunde, M

    2015-09-01

    Brain glycogen is depleted when used as an emergency energy substrate. In mammals, brain glycogen levels rebound to higher than normal levels after a hypoglycemic episode and a few hours after refeeding or administration of glucose. This phenomenon is called glycogen supercompensation. However, this mechanism has not been investigated in lower vertebrates. The aim of this study was therefore to determine whether brain glycogen supercompensation occurs in the rainbow trout brain. For this purpose, short-term brain glucose and glycogen contents were determined in rainbow trout after being subjected to the following experimental conditions: i) a 5-day or 10-day fasting period and refeeding; ii) a single injection of insulin (4 mg kg(-1)) and refeeding; and iii) sustained swimming and injection of glucose (500 mg kg(-1)). Food deprivation during the fasting periods and insulin administration both induced a decrease in glucose and glycogen levels in the brain. However, only refeeding after 10 days of fasting significantly increased the brain glycogen content above control levels, in a clear short-term supercompensation response. Unlike in mammals, prolonged exercise did not alter brain glucose or glycogen levels. Furthermore, brain glycogen supercompensation was not observed after glucose administration in fish undergoing sustained swimming. To our knowledge, this is the first study providing direct experimental evidence for the existence of a short-term glycogen supercompensation response in a teleost brain, although the response was only detectable after prolonged fasting. PMID:25956213

  5. Effects of caffeine on muscle glycogen utilization and the neuroendocrine axis during exercise.

    Science.gov (United States)

    Laurent, D; Schneider, K E; Prusaczyk, W K; Franklin, C; Vogel, S M; Krssak, M; Petersen, K F; Goforth, H W; Shulman, G I

    2000-06-01

    To examine the effect of caffeine ingestion on muscle glycogen utilization and the neuroendocrine axis during exercise, we studied 20 muscle glycogen-loaded subjects who were given placebo or caffeine (6 mg/kg) in a double blinded fashion 90 min before cycling for 2 h at 65% of their maximal oxygen consumption. Exercise-induced glycogen depletion in the thigh muscle was noninvasively measured by means of 13C nuclear magnetic resonance spectroscopy (NMR) spectroscopy, and plasma concentrations of substrates and neuroendocrine hormones, including beta-endorphins, were also assessed. Muscle glycogen content was increased 140% above normal values on the caffeine trial day (P endorphin levels almost doubled (from 30 +/- 5 to 53 +/- 13 pg/mL; P exercise does not exert a muscle glycogen-sparing effect in athletes with high muscle glycogen content. However, these data suggest that caffeine lowers the threshold for exercise-induced beta-endorphin and cortisol release, which may contribute to the reported benefits of caffeine on exercise endurance. PMID:10852448

  6. Carbohydrate supercompensation and muscle glycogen utilization during exhaustive running in highly trained athletes

    DEFF Research Database (Denmark)

    Madsen, K; Pedersen, P K; Rose, P;

    1990-01-01

    regimen (Norm), the other after a diet and training programme intended to increase muscle glycogen levels (Carb). Muscle glycogen concentration in the gastrocnemius muscle increased by 25% (P less than 0.05) from 581 mmol.kg-1 dry weight, SEM 50 to 722 mmol.kg-1 dry weight, SEM 34 after Carb. Running time...... to exhaustion, however, was not significantly different in Carb and Norm, 77 min, SEM 13 vs 70 min, SEM 8, respectively. The average glycogen concentration following exhaustive running was 553 mmol.kg-1 dry weight, SEM 70 in Carb and 434 mmol.kg-1 dry weight, SEM 57 in Norm, indicating that in both...... Carb than in Norm (0.92, SEM 0.01 vs 0.89, SEM 0.01; P less than 0.05). Since muscle glycogen utilization was identical in the two tests, the indication of higher utilization of total carbohydrate appears to be related to a higher utilization of liver glycogen. We have concluded that glycogen depletion...

  7. Persistence of supercompensated muscle glycogen in trained subjects after carbohydrate loading.

    Science.gov (United States)

    Goforth, H W; Arnall, D A; Bennett, B L; Law, P G

    1997-01-01

    Several carbohydrate (CHO)-loading protocols have been used to achieve muscle glycogen supercompensation and prolong endurance performance. This study assessed the persistence of muscle glycogen supercompensation over the 3 days after the supercompensation protocol. Trained male athletes completed a 6-day CHO-loading protocol that included cycle ergometer exercise and dietary manipulations. The 3-day depletion phase began with 115 min of cycling at 75% peak oxygen uptake followed by 3 x 60-s sprints and included the subjects consuming a low-CHO/high-protein/high-fat (10:41:49%) diet. Subjects cycled 40 min at the same intensity for the next 2 days. During the 3-day repletion phase, subjects rested and consumed a high-CHO/low-protein/low-fat (85:08:07%) diet, including a glucose-polymer beverage. A 3-day postloading phase followed, which involved a moderately high CHO diet (60%) and no exercise. Glycogen values for vastus lateralis biopsies at baseline and postloading days 1-3 were 408 +/- 168 (SD), 729 +/- 222, 648 +/- 186, and 714 +/- 196 mmol/kg dry wt, respectively. The CHO-loading protocol increased muscle glycogen by 1.79 times baseline, and muscle glycogen remained near this level during the 3-day postloading period. Results indicate that supercompensated muscle glycogen levels can be maintained for at least 3 days in a resting athlete when a moderate-CHO diet is consumed. PMID:9029236

  8. Creatine supplementation spares muscle glycogen during high intensity intermittent exercise in rats

    Directory of Open Access Journals (Sweden)

    Costa André

    2010-01-01

    Full Text Available Abstract Background The effects of creatine (CR supplementation on glycogen content are still debatable. Thus, due to the current lack of clarity, we investigated the effects of CR supplementation on muscle glycogen content after high intensity intermittent exercise in rats. Methods First, the animals were submitted to a high intensity intermittent maximal swimming exercise protocol to ensure that CR-supplementation was able to delay fatigue (experiment 1. Then, the CR-mediated glycogen sparing effect was examined using a high intensity intermittent sub-maximal exercise test (fixed number of bouts; six bouts of 30-second duration interspersed by two-minute rest interval (experiment 2. For both experiments, male Wistar rats were given either CR supplementation or placebo (Pl for 5 days. Results As expected, CR-supplemented animals were able to exercise for a significant higher number of bouts than Pl. Experiment 2 revealed a higher gastrocnemius glycogen content for the CR vs. the Pl group (33.59%. Additionally, CR animals presented lower blood lactate concentrations throughout the intermittent exercise bouts compared to Pl. No difference was found between groups in soleus glycogen content. Conclusion The major finding of this study is that CR supplementation was able to spare muscle glycogen during a high intensity intermittent exercise in rats.

  9. Preconditioning ischemia time determines the degree of glycogen depletion and infarct size reduction in rat hearts.

    Science.gov (United States)

    Barbosa, V; Sievers, R E; Zaugg, C E; Wolfe, C L

    1996-02-01

    The cardioprotective effect of preconditioning is associated with glycogen depletion and attenuation of intracellular acidosis during subsequent prolonged ischemia. This study determined the effects of increasing preconditioning ischemia time on myocardial glycogen depletion and on infarct size reduction. In addition, this study determined whether infarct size reduction by preconditioning correlates with glycogen depletion before prolonged ischemia. Anesthetized rats underwent a single episode of preconditioning lasting 1.25, 2.5, 5, or 10 minutes or multiple episodes cumulating in 10 (2 x 5 min) or 20 minutes (4 x 5 or 2 x 10 min) of preconditioning ischemia time, each followed by 5 minutes of reperfusion. Then both preconditioned and control rats underwent 45 minutes of ischemia induced by left coronary artery (LCA) occlusion and 120 minutes of reperfusion. After prolonged ischemia, infarct size was determined by dual staining with triphenyltetrazolium chloride and phthalocyanine blue dye. Glycogen levels were determined by an enzymatic assay in selected rats from each group before prolonged ischemia. We found that increasing preconditioning ischemia time resulted in glycogen depletion and infarct size reduction that could both be described by exponential functions. Furthermore, infarct size reduction correlated with glycogen depletion before prolonged ischemia (r = 0.98; p ischemic injury in the preconditioned heart. PMID:8579012

  10. Glycogen synthase kinase 3 phosphorylates RBL2/p130 during quiescence.

    Science.gov (United States)

    Litovchick, Larisa; Chestukhin, Anton; DeCaprio, James A

    2004-10-01

    Phosphorylation of the retinoblastoma-related or pocket proteins RB1/pRb, RBL1/p107, and RBL2/p130 regulates cell cycle progression and exit. While all pocket proteins are phosphorylated by cyclin-dependent kinases (CDKs) during the G1/S-phase transition, p130 is also specifically phosphorylated in G0-arrested cells. We have previously identified several phosphorylated residues that match the consensus site for glycogen synthase kinase 3 (GSK3) in the G0 form of p130. Using small-molecule inhibitors of GSK3, site-specific mutants of p130, and phospho-specific antibodies, we demonstrate here that GSK3 phosphorylates p130 during G0. Phosphorylation of p130 by GSK3 contributes to the stability of p130 but does not affect its ability to interact with E2F4 or cyclins. Regulation of p130 by GSK3 provides a novel link between growth factor signaling and regulation of the cell cycle progression and exit. PMID:15456871

  11. Glycogen synthase kinase-3: A promising therapeutic target for Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Marjelo M. Mines

    2011-11-01

    Full Text Available Recent advances in understanding the pathophysiological mechanisms contributing to Fragile X Syndrome (FXS have increased optimism that drug interventions can provide significant therapeutic benefits. FXS results from inadequate expression of functional fragile X mental retardation protein (FMRP. FMRP may have several functions, but it is most well-established as an RNA-binding protein that regulates translation, and it is by this mechanism that FMRP is capable of affecting numerous cellular processes by selectively regulating protein levels. The multiple cellular functions regulated by FMRP suggest that multiple interventions may be required for reversing the effects of deficient FMRP. Evidence that inhibitors of glycogen synthase kinase-3 (GSK3 may contribute to the therapeutic treatment of FXS is reviewed here. In the mouse model of FXS, which lacks FMRP expression (FX mice, GSK3 is hyperactive in several brain regions. Furthermore, significant improvements in several FX-related phenotypes have been obtained in FX mice following the administration of lithium, and in some case other GSK3 inhibitors. These responses include normalization of heightened audiogenic seizure susceptibility and of hyperactive locomotor behavior, enhancement of passive avoidance learning retention and of sociability behaviors, and corrections of macroorchidism, neuronal spine density, and neural plasticity measured electrophysiologically as long term depression. A pilot clinical trial of lithium in FXS patients also found improvements in several measures of behavior. Taken together, these findings indicate that lithium and other inhibitors of GSK3 are promising candidate therapeutic agents for treating FXS.

  12. Renal sonographic findings of type I glycogen storage disease in infancy and early childhood

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun-Chen; Lin, Shuan-Pei [Mackay Memorial Hospital, Department of Pediatrics, Taipei (Taiwan); Tsai, Jeng-Daw; Lee, Hung-Chang [Mackay Memorial Hospital, Department of Pediatrics, Taipei (Taiwan); Taipei Medical University, Department of Pediatrics, Taipei (Taiwan)

    2005-08-01

    Type I glycogen storage disease (GSD-I) is an inherited disorder affecting glycogenolysis and gluconeogenesis. The characteristic manifestations are hepatomegaly, hypoglycemia, hyperlacticacidemia, hyperuricemia, and hyperlipidemia. Renal disease is regarded as a long-term complication and is reported mainly in older patients. We report the renal manifestations and renal ultrasonographic findings of GSD-I in infancy and early childhood in order to assess the role of renal sonography in the diagnosis of GSD-I. We retrospectively reviewed our hospital's database for patients with GSD-I from January 1993 to September 2004. The records of five patients were reviewed for this study. These five patients were diagnosed when they were younger than 3 years old. Data extracted from the charts included the initial extrarenal and renal manifestations, laboratory data, and imaging studies. We analyzed the indications for, and results of, renal sonography. In addition to the clinical presentations and laboratory abnormalities, all five children had nephromegaly and increased echogenicity on ultrasonography on their first visit, although only a minor degree of tubular dysfunction was noted clinically. Three of these five patients had nephrocalcinosis or renal stones or both. Hyperechoic large kidneys, nephrocalcinosis, and renal stones are common in GSD-I. They can be present in early infancy. Abnormalities on renal sonography might suggest GSD-I in a patient with suspected inborn errors of metabolism. (orig.)

  13. Renal sonographic findings of type I glycogen storage disease in infancy and early childhood

    International Nuclear Information System (INIS)

    Type I glycogen storage disease (GSD-I) is an inherited disorder affecting glycogenolysis and gluconeogenesis. The characteristic manifestations are hepatomegaly, hypoglycemia, hyperlacticacidemia, hyperuricemia, and hyperlipidemia. Renal disease is regarded as a long-term complication and is reported mainly in older patients. We report the renal manifestations and renal ultrasonographic findings of GSD-I in infancy and early childhood in order to assess the role of renal sonography in the diagnosis of GSD-I. We retrospectively reviewed our hospital's database for patients with GSD-I from January 1993 to September 2004. The records of five patients were reviewed for this study. These five patients were diagnosed when they were younger than 3 years old. Data extracted from the charts included the initial extrarenal and renal manifestations, laboratory data, and imaging studies. We analyzed the indications for, and results of, renal sonography. In addition to the clinical presentations and laboratory abnormalities, all five children had nephromegaly and increased echogenicity on ultrasonography on their first visit, although only a minor degree of tubular dysfunction was noted clinically. Three of these five patients had nephrocalcinosis or renal stones or both. Hyperechoic large kidneys, nephrocalcinosis, and renal stones are common in GSD-I. They can be present in early infancy. Abnormalities on renal sonography might suggest GSD-I in a patient with suspected inborn errors of metabolism. (orig.)

  14. Route of administration of pentobarbital affects activity of liver glycogen phosphorylase

    DEFF Research Database (Denmark)

    Mikines, K J; Sonne, B; Richter, Erik;

    1986-01-01

    Liver phosphorylase a activity in intact animals is mostly determined during anesthesia. The aim of this study was to investigate the effect of administering pentobarbital by different routes on activity of liver phosphorylase a. Rats had chronically implanted venous catheters and received pentob...... by differences in duration before the drug takes effect. It is proposed that intraperitoneal injection of pentobarbital may anesthetize hepatic sympathetic nerves or have a direct inhibiting effect on phosphorylase a activity....

  15. Influence of pre-exercise muscle glycogen content on exercise-induced transcriptional regulation of metabolic genes

    DEFF Research Database (Denmark)

    Pilegaard, Henriette; Keller, Charlotte; Steensberg, Adam;

    2002-01-01

    Transcription of metabolic genes is transiently induced during recovery from exercise in skeletal muscle of humans. To determine whether pre-exercise muscle glycogen content influences the magnitude and/or duration of this adaptive response, six male subjects performed one-legged cycling exercise...... to lower muscle glycogen content in one leg and then, the following day, completed 2.5 h low intensity two-legged cycling exercise. Nuclei and mRNA were isolated from biopsies obtained from the vastus lateralis muscle of the control and reduced glycogen (pre-exercise glycogen = 609 +/- 47 and 337...... of PDK4 and UCP3 mRNA in response to exercise was also significantly higher in the low glycogen (11.4- and 3.5-fold, respectively) than in the control (5.0- and 1.7-fold, respectively) trial. These data indicate that low muscle glycogen content enhances the transcriptional activation of some...

  16. Astrocyte glycogen metabolism is required for neural activity during aglycemia or intense stimulation in mouse white matter

    DEFF Research Database (Denmark)

    Brown, Angus M; Sickmann, Helle M; Fosgerau, Keld;

    2005-01-01

    We tested the hypothesis that inhibiting glycogen degradation accelerates compound action potential (CAP) failure in mouse optic nerve (MON) during aglycemia or high-intensity stimulation. Axon function was assessed as the evoked CAP, and glycogen content was measured biochemically. Isofagomine, a...... novel inhibitor of central nervous system (CNS) glycogen phosphorylase, significantly increased glycogen content under normoglycemic conditions. When MONs were bathed in artificial cerebrospinal fluid (aCSF) containing 10 mM glucose, the CAP failed 16 min after exposure to glucose-free aCSF. MONs bathed...... in aCSF plus isofagomine displayed accelerated CAP failure on glucose removal. Similar results were obtained in MONs bathed in 30 mM glucose, which increased baseline glycogen concentration. The ability of isofagomine to increase glycogen content thus was not translated into delayed CAP failure. This...

  17. Neutropenia, neutrophil dysfunction, and inflammatory bowel disease in glycogen storage disease type Ib : Results of the European Study on Glycogen Storage Disease Type I

    NARCIS (Netherlands)

    Visser, G; Rake, JP; Fernandes, J; Labrune, P; Leonard, JV; Moses, S; Ullrich, K; Smit, GPA

    2000-01-01

    Objective: To investigate the incidence, the severity, and the course of neutropenia, neutrophil dysfunction, and inflammatory bowel disease (IBD) in glycogen storage disease (GSD) type Ib. Method: As part of a collaborative European Study on GSD type I, a retrospective registry was established in 1

  18. Granulocyte colony-stimulating factor in glycogen storage disease type 1b. Results of the European Study on Glycogen Storage Disease Type 1

    NARCIS (Netherlands)

    Visser, G.; Rake, J.P.; Labrune, P.; Leonard, J.V.; Moses, S.; Ullrich, K.; Wendel, U.; Groenier, K.H.; Smit, G.P.

    2002-01-01

    Patients with glycogen storage disease type 1b (GSD-1b) have neutropenia and neutrophil dysfunction that predispose to frequent infections and inflammatory bowel disease (IBD), for which granulocyte colony-stimulating factor (GCSF) is given. To investigate the use and the value of GCSF treatment in

  19. Modelling the metabolic shift of polyphosphate-accumulating organisms.

    Science.gov (United States)

    Acevedo, B; Borrás, L; Oehmen, A; Barat, R

    2014-11-15

    Enhanced biological phosphorus removal (EBPR) is one of the most important methods of phosphorus removal in municipal wastewater treatment plants, having been described by different modelling approaches. In this process, the PAOs (polyphosphate accumulating organisms) and GAOs (glycogen accumulating organisms) compete for volatile fatty acids uptake under anaerobic conditions. Recent studies have revealed that the metabolic pathways used by PAOs in order to obtain the energy and the reducing power needed for polyhydroxyalkanoates synthesis could change depending on the amount of polyphosphate stored in the cells. The model presented in this paper extends beyond previously developed metabolic models by including the ability of PAO to change their metabolic pathways according to the content of poly-P available. The processes of the PAO metabolic model were adapted to new formulations enabling the change from P-driven VFA uptake to glycogen-driven VFA uptake using the same process equations. The stoichiometric parameters were changed from a typical PAO coefficient to a typical GAO coefficient depending on the internal poly-P with Monod-type expressions. The model was calibrated and validated with seven experiments under different internal poly-P concentrations, showing the ability to correctly represent the PAO metabolic shift at low poly-P concentrations. The sensitivity and error analysis showed that the model is robust and has the ability to describe satisfactorily the change from one metabolic pathway to the other one, thereby encompassing a wider range of process conditions found in EBPR plants. PMID:25123437

  20. Quantitative comparison of pathways of hepatic glycogen repletion in fed and fasted humans

    International Nuclear Information System (INIS)

    The effect of fasting vs. refeeding on hepatic glycogen repletion by the direct pathway, i.e., glucose----glucose 6-phosphate (G-6-P)----glycogen, was determined. Acetaminophen was administered during an infusion of glucose labeled with [1-13C]- and [6-14C]glucose into four healthy volunteers after an overnight fast and into the same subjects 4 h after breakfast. 13C enrichments in C-1 and C-6 of glucose formed from urinary acetaminophen glucuronide compared with enrichments in C-1 and C-6 of plasma glucose provided an estimate of glycogen formation by the direct pathway. The specific activity of glucose from the glucuronide compared with the specific activity of the plasma glucose, along with the percentages of 14C in C-1 and C-6 of the glucose from the glucuronide, also provided an estimate of the amount of glycogen formed by the direct pathway. The estimates were similar. Those from [6-14C]glucose would have been higher than from [1-13C]glucose if the pentose cycle contribution to overall glucose utilization had been significant. After an overnight fast, during the last hour of infusion, 49 +/- 3% of the glycogen formed was formed via the direct pathway. After breakfast, at similar plasma glucose and insulin concentrations, the percentage increased to 69 +/- 7% (P less than 0.02). Thus the contributions of the pathways to hepatic glycogen formation depend on the dietary state of the individual. For a dietary regimen in which individuals consume multiple meals per day containing at least a moderate amount of carbohydrates most glycogen synthesis occurs by the direct pathway

  1. Glycogenotic hepatocellular carcinoma with glycogen-ground-glass hepatocytes: A heuristically highly relevant phenotype

    Institute of Scientific and Technical Information of China (English)

    Peter Bannasch

    2012-01-01

    Glycogenotic hepatocellular carcinoma (HCC) with glycogen-ground-glass hepatocytes has recently been described as an allegedly "novel variant" of HCC,but neither the historical background nor the heuristic relevance of this observation were put in perspective.In the present contribution,the most important findings in animal models and human beings related to the emergence and further evolution of excessively glycogen storing (glycogenotic) hepatocytes with and without ground glass features during neoplastic development have been summarized.Glycogenotic HCCs with glycogen-ground-glass hepatocytes represent highly differentiated neoplasms which contain subpopulations of cells phenotypically resembling those of certain types of preneoplastic hepatic foci and benign hepatocellular neoplasms.It is questionable whether the occurrence of glycogen-ground-glass hepatocytes in a glycogenotic HCC justifies its classification as a specific entity.The typical appearance of ground-glass hepatocytes is due to a hypertrophy of the smooth endoplasmic reticulum,which is usually associated with an excessive storage of glycogen and frequently also with an expression of the hepatitis B surface antigen.Sequential studies in animal models and observations in humans indicate that glycogen-ground-glass hepatocytes are a facultative,integral part of a characteristic cellular sequence commencing with focal hepatic glycogenosis potentially progressing to benign and malignant neoplasms.During this process highly differentiated glycogenotic cells including ground-glass hepatocytes are gradually transformed via various intermediate stages into poorly differentiated glycogen-poor,basophilic (ribosome-rich) cancer cells.Histochemical,microbiochemical,and molecular biochemical studies on focal hepatic glycogenosis and advanced preneoplastic and neoplastic lesions in tissue sections and laser-dissected specimens in rat and mouse models have provided compelling evidence for an early insulinomimetic

  2. Muscle-Specific Deletion of the Glut4 Glucose Transporter Alters Multiple Regulatory Steps in Glycogen Metabolism

    OpenAIRE

    Kim, Young-Bum; Peroni, Odile D.; Aschenbach, William G.; Minokoshi, Yasuhiko; Kotani, Ko; Zisman, Ariel; Kahn, C. Ronald; Goodyear, Laurie J.; Kahn, Barbara B.

    2005-01-01

    Mice with muscle-specific knockout of the Glut4 glucose transporter (muscle-G4KO) are insulin resistant and mildly diabetic. Here we show that despite markedly reduced glucose transport in muscle, muscle glycogen content in the fasted state is increased. We sought to determine the mechanism(s). Basal glycogen synthase activity is increased by 34% and glycogen phosphorylase activity is decreased by 17% (P < 0.05) in muscle of muscle-G4KO mice. Contraction-induced glycogen breakdown is normal. ...

  3. Natural Resource Abundance and Human Capital Accumulation

    OpenAIRE

    Jean-Philippe C. Stijns

    2001-01-01

    This study examines indicators of human capital accumulation together with data for natural resource abundance and rents in a panel of 102 countries running from 1970 to 1999. Mineral wealth makes a positive and marked difference on human capital accumulation. Matching on observables reveals that cross-country results are not driven by a third factor such as overall economic development. Political stability does seem to affect both human capital accumulation and subsoil wealth, but not enough...

  4. Brain glycogen content and metabolism in subjects with type 1 diabetes and hypoglycemia unawareness.

    Science.gov (United States)

    Öz, Gülin; Tesfaye, Nolawit; Kumar, Anjali; Deelchand, Dinesh K; Eberly, Lynn E; Seaquist, Elizabeth R

    2012-02-01

    Supercompensated brain glycogen may contribute to the development of hypoglycemia unawareness in patients with type 1 diabetes by providing energy for the brain during periods of hypoglycemia. Our goal was to determine if brain glycogen content is elevated in patients with type 1 diabetes and hypoglycemia unawareness. We used in vivo (13)C nuclear magnetic resonance spectroscopy in conjunction with [1-(13)C]glucose administration in five patients with type 1 diabetes and hypoglycemia unawareness and five age-, gender-, and body mass index-matched healthy volunteers to measure brain glycogen content and metabolism. Glucose and insulin were administered intravenously over ∼51 hours at a rate titrated to maintain a blood glucose concentration of 7 mmol/L. (13)C-glycogen levels in the occipital lobe were measured at ∼5, 8, 13, 23, 32, 37, and 50 hours, during label wash-in and wash-out. Newly synthesized glycogen levels were higher in controls than in patients (Psupercompensation does not contribute to the development of hypoglycemia unawareness in humans with type 1 diabetes. PMID:21971353

  5. The post-exercise glycogen recovery in tissues of trained rats.

    Science.gov (United States)

    Górski, J; Palka, P; Puch, U; Kiczka, K

    1976-01-01

    The post-exercise glycogen recovery in myocardium, liver, diaphragm muscle and musculus biceps femoris was compared in untrained and trained rats. The glycogen level in myocardium of the trained rats was significantly higher than that in the untrained ones only immediately after the exercise-test and on the second day after the exercise. The liver glycogen levels on each of the examined post-exercise days were similar in both groups and did not differ from the control values. The post-exercise glycogen recovery in the diapraghm muscle of the untrained rats was also similar to that in the trained animals. In musculus bicpes femoris similar post-exercise supercompensation was found in both groups except on the second day when the glycogen level in the trained animals was significantly higher than that in the untrained ones. The results suggest that it is necessary to separate the effects of training from those of the last bout of exercise in the training program when the effect of training is examined. PMID:1274602

  6. Platelet-derived growth factor (PDGF) stimulates glycogen synthase activity in 3T3 cells

    International Nuclear Information System (INIS)

    Hormonal regulation of glycogen synthase, an enzyme that can be phosphorylated on multiple sites, is often associated with changes in its phosphorylation state. Enzyme activation is conventionally monitored by determining the synthase activity ratio [(activity in the absence of glucose 6-P)/(activity in the presence of glucose 6-P)]. Insulin causes an activation of glycogen synthase with a concomitant decrease in its phosphate content. In a previous report, the authors showed that epidermal growth factor (EGF) increases the glycogen synthase activity ratio in Swiss 3T3 cells. The time and dose-dependency of this response was similar to that of insulin. Their recent results indicate that PDGF also stimulates glycogen synthase activity. Enzyme activation was maximal after 30 min. of incubation with PDGF; the time course observed was very similar to that with insulin and EGF. At 1 ng/ml (0.03nM), PDGF caused a maximal stimulation of 4-fold in synthase activity ratio. Half-maximal stimulation was observed at 0.2 ng/ml (6 pM). The time course of changes in enzyme activity ratio closely followed that of 125I-PDGF binding. The authors data suggest that PDGF, as well as EFG and insulin, may be important in regulating glycogen synthesis through phosphorylation/dephosphorylation mechanisms

  7. Nardostachys Jatamansi root extract protects of radiation induced glycogen depletion in Albino Wistar rats

    International Nuclear Information System (INIS)

    Exposure to ionizing radiation cause variety of pathological processes in irradiated cells. The killing action of ionizing radiation is mainly mediated through the free radicals generated from the radiolysis of cellular water. In the present study, protective effects of Nardostachys Jatamansi root extract (NJE) on radiation induced depletion of glycogen in rats exposed to 3 Gy whole body electron beam irradiation (EBR) was investigated. EBR was performed at Microtron centre, Mangalore University. Treatment of rats with NJE at a dosage of 100, 200 and 400 mg/kg bw respectively once daily for 15 days before, after and both before and after irradiation was done. The liver, kidney and muscle was separated and used for the estimation of total glycogen content using standard procedures and also for the histochemical localization of glycogen by PAS staining method. The data was analyzed by paired t test and Kruskal Wallis test. P<0.05 was the level of significance. The irradiated rats exhibited significant decline (p=0.000) in the level of total glycogen content in the tissues of liver, kidney and muscle whereas, a nonsignificant variation was recorded in rats treated with NJE. This study indicated that treatment with NJE both before and after irradiation for 15 consecutive days provided significant protection against irradiation induced depletion of glycogen. (author)

  8. Impact of salinity on the aerobic metabolism of phosphate-accumulating organisms.

    Science.gov (United States)

    Welles, L; Lopez-Vazquez, C M; Hooijmans, C M; van Loosdrecht, M C M; Brdjanovic, D

    2015-04-01

    The use of saline water in urban areas for non-potable purposes to cope with fresh water scarcity, intrusion of saline water, and disposal of industrial saline wastewater into the sewerage lead to elevated salinity levels in wastewaters. Consequently, saline wastewater is generated, which needs to be treated before its discharge into surface water bodies. The objective of this research was to study the effects of salinity on the aerobic metabolism of phosphate-accumulating organisms (PAO), which belong to the microbial populations responsible for enhanced biological phosphorus removal (EBPR) in activated sludge systems. In this study, the short-term impact (hours) of salinity (as NaCl) was assessed on the aerobic metabolism of a PAO culture, enriched in a sequencing batch reactor (SBR). All aerobic PAO metabolic processes were drastically affected by elevated salinity concentrations. The aerobic maintenance energy requirement increased, when the salinity concentration rose up to a threshold concentration of 2 % salinity (on a W/V basis as NaCl), while above this concentration, the maintenance energy requirements seemed to decrease. All initial rates were affected by salinity, with the NH4- and PO4-uptake rates being the most sensitive. A salinity increase from 0 to 0.18 % caused a 25, 46, and 63 % inhibition of the O2, PO4, and NH4-uptake rates. The stoichiometric ratios of the aerobic conversions confirmed that growth was the process with the highest inhibition, followed by poly-P and glycogen formation. The study indicates that shock loads of 0.18 % salt, which corresponds to the use or intrusion of about 5 % seawater may severely affect the EBPR process already in wastewater treatment plants not exposed regularly to high salinity concentrations. PMID:25524698

  9. Role of glucose transport in glycogen supercompensation in reweighted rat skeletal muscle.

    Science.gov (United States)

    Henriksen, E J; Stump, C S; Trinh, T H; Beaty, S D

    1996-05-01

    Hindlimb weight bearing after a 3-day period of hindlimb suspension (reweighting) of juvenile rats results in a marked transient elevation in soleus glycogen concentration that cannot be explained on the basis of the activities of glycogen synthase and phosphorylase. We have hypothesized that enhanced glucose transport activity could underlie this response. We directly tested this hypothesis by assessing the response of insulin-dependent and insulin-independent glucose transport activity (in vitro 2-[1,2-3H]deoxy-D-glucose uptake) as well as glucose transporter (GLUT-4) protein levels during a 48-h reweighting period. After a net glycogen loss (from 29 +/- 2 to 16 +/- 1 nmol/mg muscle; P supercompensation seen during reweighting of the rat soleus may be regulated in part by an enhanced glucose flux arising from an increase in insulin-independent glucose transport activity and hexokinase activity. PMID:8727537

  10. Postexercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements.

    Science.gov (United States)

    Cramer, Michael J; Dumke, Charles L; Hailes, Walter S; Cuddy, John S; Ruby, Brent C

    2015-10-01

    A variety of dietary choices are marketed to enhance glycogen recovery after physical activity. Past research informs recommendations regarding the timing, dose, and nutrient compositions to facilitate glycogen recovery. This study examined the effects of isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and exercise performance. Eleven males completed two experimental trials in a randomized, counterbalanced order. Each trial included a 90-min glycogen depletion ride followed by a 4-hr recovery period. Absolute amounts of macronutrients (1.54 ± 0.27 g·kg-1 carbohydrate, 0.24 ± 0.04 g·kg fat-1, and 0.18 ±0.03g·kg protein-1) as either SS or FF were provided at 0 and 2 hr. Muscle biopsies were collected from the vastus lateralis at 0 and 4 hr post exercise. Blood samples were analyzed at 0, 30, 60, 120, 150, 180, and 240 min post exercise for insulin and glucose, with blood lipids analyzed at 0 and 240 min. A 20k time-trial (TT) was completed following the final muscle biopsy. There were no differences in the blood glucose and insulin responses. Similarly, rates of glycogen recovery were not different across the diets (6.9 ± 1.7 and 7.9 ± 2.4 mmol·kg wet weight- 1·hr-1 for SS and FF, respectively). There was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7 min for SS and FF, respectively. These data indicate that short-term food options to initiate glycogen resynthesis can include dietary options not typically marketed as sports nutrition products such as fast food menu items. PMID:25811308

  11. Effect of exercise-diet manipulation on muscle glycogen and its subsequent utilization during performance.

    Science.gov (United States)

    Sherman, W M; Costill, D L; Fink, W J; Miller, J M

    1981-05-01

    This study examined the effect of three exercise-diet regimens on muscle glycogen supercompensation and subsequent performance during a 20.9-km run. A diet containing 15% carbohydrate (CHO,L), 50% CHO (M), or 70% (CHO (H) was arranged in three trials as follows: trial A = 3 days L, 3 days H; trial B = 3 days M, 3 days H; trial C = 6 days M. For each trial a 5-day depletion-taper exercise sequence was conducted on the treadmill at 73% VO2 max. The runs were 90, 40, 40, 20, and 20 min, respectively. A day of rest preceded the 20.9-km performance run. Muscle biopsies were obtained from the gastrocnemius on days 4 and 7 (both prior to and after the performance run). Trials A, B, and C elevated muscle glycogen to 207, 203, and 159 mmol glucosyl units/kg wet tissue (mmG), respectively. The performance run in both trials A and B utilized significantly more glycogen than in trial C: 5.0 and 5.1 mmG/km vs. 3.1 mmG/km. There were, however, no differences in either performance run times or post-performance run glycogen levels between the trials. These data demonstrate that (1) muscle glycogen can be elevated to high levels with a moderate exercise-diet regimen; (2) initial muscle glycogen levels influence the amount subsequently utilized during exercise; (3) carbohydrate loading is of no benefit to performance for trained runners during a 20.9-km run. PMID:7333741

  12. Glycogen repletion and exercise endurance in rats adapted to a high fat diet.

    Science.gov (United States)

    Conlee, R K; Hammer, R L; Winder, W W; Bracken, M L; Nelson, A G; Barnett, D W

    1990-03-01

    It is well accepted that exercise endurance is directly related to the amount of carbohydrate stored in muscle and that a low carbohydrate diet reduces glycogen storage and exercise performance. However, more recent evidence has shown that when the organism adapts to a high fat diet endurance is not hindered. The present study was designed to test that claim and to further determine if animals adapted to a high fat diet could recover from exhausting exercise and exercise again in spite of carbohydrate deprivation. Fat-adapted (3 to 4 weeks, 78% fat, 1% carbohydrates) rats (FAT) ran (28 m/min, 10% grade) as long as carbohydrate-fed (69% carbohydrates) animals (CHO) (115 v 109 minutes, respectively) in spite of lower pre-exercise glycogen levels in red vastus muscle (36 v 54 mumols/g) and liver (164 v 313 mumols/g) in the FAT group. Following 72 hours of recovery on the FAT diet, glycogen in muscle had replenished to 42 mumols/g (v 52 for CHO) and liver glycogen to 238 mumols/g (v 335 for CHO). The animals were run to exhaustion a second time and run times were again similar (122 v 132 minutes FAT v CHO). When diets were switched after run 1, FAT-adapted animals, which received carbohydrates for 72 hours, restored muscle and liver glycogen (48 and 343 mumols/g, respectively) and then ran longer (144 minutes) than CHO-adapted animals (104 minutes) that ate fat for 72 hours and that had reduced glycogen repletion. We conclude that, in contrast to the classic CHO loading studies in humans that involved acute (72 hours) fat feedings and subsequently reduced endurance, rats adapted to a high fat diet do not have a decrease in endurance capacity even after recovery from previous exhausting work bouts. Part of this adaptation may involve the increased storage and utilization of intramuscular triglycerides (TG) as observed in the present experiment. PMID:2308519

  13. The pharmacological chaperone AT2220 increases the specific activity and lysosomal delivery of mutant acid alpha-glucosidase, and promotes glycogen reduction in a transgenic mouse model of Pompe disease.

    Directory of Open Access Journals (Sweden)

    Richie Khanna

    Full Text Available Pompe disease is an inherited lysosomal storage disorder that results from a deficiency in acid α-glucosidase (GAA activity due to mutations in the GAA gene. Pompe disease is characterized by accumulation of lysosomal glycogen primarily in heart and skeletal muscles, which leads to progressive muscle weakness. We have shown previously that the small molecule pharmacological chaperone AT2220 (1-deoxynojirimycin hydrochloride, duvoglustat hydrochloride binds and stabilizes wild-type as well as multiple mutant forms of GAA, and can lead to higher cellular levels of GAA. In this study, we examined the effect of AT2220 on mutant GAA, in vitro and in vivo, with a primary focus on the endoplasmic reticulum (ER-retained P545L mutant form of human GAA (P545L GAA. AT2220 increased the specific activity of P545L GAA toward both natural (glycogen and artificial substrates in vitro. Incubation with AT2220 also increased the ER export, lysosomal delivery, proteolytic processing, and stability of P545L GAA. In a new transgenic mouse model of Pompe disease that expresses human P545L on a Gaa knockout background (Tg/KO and is characterized by reduced GAA activity and elevated glycogen levels in disease-relevant tissues, daily oral administration of AT2220 for 4 weeks resulted in significant and dose-dependent increases in mature lysosomal GAA isoforms and GAA activity in heart and skeletal muscles. Importantly, oral administration of AT2220 also resulted in significant glycogen reduction in disease-relevant tissues. Compared to daily administration, less-frequent AT2220 administration, including repeated cycles of 4 or 5 days with AT2220 followed by 3 or 2 days without drug, respectively, resulted in even greater glycogen reductions. Collectively, these data indicate that AT2220 increases the specific activity, trafficking, and lysosomal stability of P545L GAA, leads to increased levels of mature GAA in lysosomes, and promotes glycogen reduction in situ. As

  14. Cinnamon improves insulin sensitivity, prevents mesenteric fat accumulation, and increases glycogen synthesis in an animal model of the metabolic syndrome

    Science.gov (United States)

    In Western countries, over consumption of fat and/or refined carbohydrates are leading causes of insulin resistance, obesity, and the metabolic syndrome. Some nutritional factors, including many polyphenols, may be beneficial in counteracting insulin resistance associated with the metabolic syndrom...

  15. A whole-body model for glycogen regulation reveals a critical role for substrate cycling in maintaining blood glucose homeostasis.

    Directory of Open Access Journals (Sweden)

    Ke Xu

    2011-12-01

    Full Text Available Timely, and sometimes rapid, metabolic adaptation to changes in food supply is critical for survival as an organism moves from the fasted to the fed state, and vice versa. These transitions necessitate major metabolic changes to maintain energy homeostasis as the source of blood glucose moves away from ingested carbohydrates, through hepatic glycogen stores, towards gluconeogenesis. The integration of hepatic glycogen regulation with extra-hepatic energetics is a key aspect of these adaptive mechanisms. Here we use computational modeling to explore hepatic glycogen regulation under fed and fasting conditions in the context of a whole-body model. The model was validated against previous experimental results concerning glycogen phosphorylase a (active and glycogen synthase a dynamics. The model qualitatively reproduced physiological changes that occur during transition from the fed to the fasted state. Analysis of the model reveals a critical role for the inhibition of glycogen synthase phosphatase by glycogen phosphorylase a. This negative regulation leads to high levels of glycogen synthase activity during fasting conditions, which in turn increases substrate (futile cycling, priming the system for a rapid response once an external source of glucose is restored. This work demonstrates that a mechanistic understanding of the design principles used by metabolic control circuits to maintain homeostasis can benefit from the incorporation of mathematical descriptions of these networks into "whole-body" contextual models that mimic in vivo conditions.

  16. Decreased glycogen synthase kinase-3 levels and activity contribute to Huntington's disease.

    Science.gov (United States)

    Fernández-Nogales, Marta; Hernández, Félix; Miguez, Andrés; Alberch, Jordi; Ginés, Silvia; Pérez-Navarro, Esther; Lucas, José J

    2015-09-01

    Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by brain atrophy particularly in striatum leading to personality changes, chorea and dementia. Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase in the crossroad of many signaling pathways that is highly pleiotropic as it phosphorylates more than hundred substrates including structural, metabolic, and signaling proteins. Increased GSK-3 activity is believed to contribute to the pathogenesis of neurodegenerative diseases like Alzheimer's disease and GSK-3 inhibitors have been postulated as therapeutic agents for neurodegeneration. Regarding HD, GSK-3 inhibitors have shown beneficial effects in cell and invertebrate animal models but no evident efficacy in mouse models. Intriguingly, those studies were performed without interrogating GSK-3 level and activity in HD brain. Here we aim to explore the level and also the enzymatic activity of GSK-3 in the striatum and other less affected brain regions of HD patients and of the R6/1 mouse model to then elucidate the possible contribution of its alteration to HD pathogenesis by genetic manipulation in mice. We report a dramatic decrease in GSK-3 levels and activity in striatum and cortex of HD patients with similar results in the mouse model. Correction of the GSK-3 deficit in HD mice, by combining with transgenic mice with conditional GSK-3 expression, resulted in amelioration of their brain atrophy and behavioral motor and learning deficits. Thus, our results demonstrate that decreased brain GSK-3 contributes to HD neurological phenotype and open new therapeutic opportunities based on increasing GSK-3 activity or attenuating the harmful consequences of its decrease. PMID:26082469

  17. Identification of a Glycogen Synthase Kinase-3[beta] Inhibitor that Attenuates Hyperactivity in CLOCK Mutant Mice

    Energy Technology Data Exchange (ETDEWEB)

    Kozikowski, Alan P.; Gunosewoyo, Hendra; Guo, Songpo; Gaisina, Irina N.; Walter, Richard L.; Ketcherside, Ariel; McClung, Colleen A.; Mesecar, Andrew D.; Caldarone, Barbara (Psychogenics); (Purdue); (UIC); (UTSMC)

    2012-05-02

    Bipolar disorder is characterized by a cycle of mania and depression, which affects approximately 5 million people in the United States. Current treatment regimes include the so-called 'mood-stabilizing drugs', such as lithium and valproate that are relatively dated drugs with various known side effects. Glycogen synthase kinase-3{beta} (GSK-3{beta}) plays a central role in regulating circadian rhythms, and lithium is known to be a direct inhibitor of GSK-3{beta}. We designed a series of second generation benzofuran-3-yl-(indol-3-yl)maleimides containing a piperidine ring that possess IC{sub 50} values in the range of 4 to 680 nM against human GSK-3{beta}. One of these compounds exhibits reasonable kinase selectivity and promising preliminary absorption, distribution, metabolism, and excretion (ADME) data. The administration of this compound at doses of 10 to 25 mg kg{sup -1} resulted in the attenuation of hyperactivity in amphetamine/chlordiazepoxide-induced manic-like mice together with enhancement of prepulse inhibition, similar to the effects found for valproate (400 mg kg{sup -1}) and the antipsychotic haloperidol (1 mg kg{sup -1}). We also tested this compound in mice carrying a mutation in the central transcriptional activator of molecular rhythms, the CLOCK gene, and found that the same compound attenuates locomotor hyperactivity in response to novelty. This study further demonstrates the use of inhibitors of GSK-3{beta} in the treatment of manic episodes of bipolar/mood disorders, thus further validating GSK-3{beta} as a relevant therapeutic target in the identification of new therapies for bipolar patients.

  18. Brain glycogen and its role in supporting glutamate and GABA homeostasis in a type 2 diabetes rat model

    DEFF Research Database (Denmark)

    Sickmann, Helle Mark; Waagepetersen, Helle S.; Schousboe, Arne;

    2012-01-01

    diabetic state. Also, our objective was to elucidate the contribution of glycogen to support neurotransmitter glutamate and GABA homeostasis. A glycogen phosphorylase (GP) inhibitor was administered to Sprague-Dawley (SprD) and Zucker Diabetic Fatty (ZDF) rats in vivo and after one day of treatment [1......-(13)C]glucose was used to monitor metabolism. Brain levels of (13)C labeling in glucose, lactate, alanine, glutamate, GABA, glutamine and aspartate were determined. Our results show that inhibition of brain glycogen metabolism reduced the amounts of glutamate in both the control and type 2 diabetes......The number of people suffering from diabetes is hastily increasing and the condition is associated with altered brain glucose homeostasis. Brain glycogen is located in astrocytes and being a carbohydrate reservoir it contributes to glucose homeostasis. Furthermore, glycogen has been indicated to be...

  19. Chromosomal mapping and mutational analysis of the coding region of the glycogen synthase kinase-3alpha and beta isoforms in patients with NIDDM

    DEFF Research Database (Denmark)

    Hansen, L; Arden, K C; Rasmussen, S B;

    1997-01-01

    Activation of glycogen synthesis in skeletal muscle in response to insulin results from the combined inactivation of glycogen synthase kinase-3 (GSK-3) and activation of the protein phosphatase-1, changing the ratio between the inactive phosphorylated state of the glycogen synthase to the active ...

  20. In vivo portal-hepatic venous gradients of glycogenic precursors and incorporation of D-(3- sup 3 H)glucose into liver glycogen in the awake rat

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, G.P.; Veech, R.L.; Passonneau, J.V.; Huang, M.T. (National Institute on Alcohol Abuse and Alcoholism, Rockville, MD (USA))

    1990-09-25

    Male Wistar fed rats were chronically cannulated and fed ground chow for 2 h for 6 days. On the 7th post-operative day, blood was simultaneously drawn from the portal and hepatic veins over a 2-h feeding period. The position of the hepatic vein cannula was verified using a tritiated water washout technique. In separate experiments, 200 microCi of (3-3H)glucose was added to the food in order to determine the contribution of D-glucose and 3-C precursors to newly synthesized glycogen. The 22-h fasting plasma portal vein concentrations of D-glucose, L-lactate, and L-alanine were 4.8 +/- 0.03, 0.81 +/- 0.06, and 0.20 +/- 0.03 mM, respectively (n = 5). The fasting hepatic vein plasma concentrations were 5.1 +/- 0.2, 0.70 +/- 0.15 and 0.19 +/- 0.03 mM, respectively. The portal-hepatic vein gradients after 22 h were -0.24, +0.16, and +0.01 mM for D-glucose, L-lactate, and L-alanine, respectively. At 20 min after beginning the meal, the respective gradients were +2.2, +0.53, and +0.44 mM, indicating hepatic uptake of all glycogen precursors. Of the total carbon from the three major precursors entering the liver as C-6, D-glucose contributed 82%, while alanine and lactate contributed 18% at 20 min. As portal vein D-glucose and L-alanine levels exceeded 6.65 +/- 0.69 and 0.32 +/- 0.07 mM, respectively, the portal-hepatic venous gradient became positive and increased linearly with portal concentrations. The glycogen concentration in the liver increased from a 22-h fast value of 5 mumol of glucosyl units/g wet weight to 101 +/- 7 mumol/g 2 h after the meal. The mean specific activity of portal vein plasma of (3-3H)glucose was 11,490 +/- 1,180 dpm/mumol (+/- S.E.) and that in the glycogen isolated from liver was 8,175 +/- 785 dpm/mumol of glycosyl units 2 h after the meal. The specific activity of liver (3H)glycogen relative to glucose after the meal was 0.73 +/- 0.08.

  1. In vivo portal-hepatic venous gradients of glycogenic precursors and incorporation of D-[3-3H]glucose into liver glycogen in the awake rat

    International Nuclear Information System (INIS)

    Male Wistar fed rats were chronically cannulated and fed ground chow for 2 h for 6 days. On the 7th post-operative day, blood was simultaneously drawn from the portal and hepatic veins over a 2-h feeding period. The position of the hepatic vein cannula was verified using a tritiated water washout technique. In separate experiments, 200 microCi of [3-3H]glucose was added to the food in order to determine the contribution of D-glucose and 3-C precursors to newly synthesized glycogen. The 22-h fasting plasma portal vein concentrations of D-glucose, L-lactate, and L-alanine were 4.8 +/- 0.03, 0.81 +/- 0.06, and 0.20 +/- 0.03 mM, respectively (n = 5). The fasting hepatic vein plasma concentrations were 5.1 +/- 0.2, 0.70 +/- 0.15 and 0.19 +/- 0.03 mM, respectively. The portal-hepatic vein gradients after 22 h were -0.24, +0.16, and +0.01 mM for D-glucose, L-lactate, and L-alanine, respectively. At 20 min after beginning the meal, the respective gradients were +2.2, +0.53, and +0.44 mM, indicating hepatic uptake of all glycogen precursors. Of the total carbon from the three major precursors entering the liver as C-6, D-glucose contributed 82%, while alanine and lactate contributed 18% at 20 min. As portal vein D-glucose and L-alanine levels exceeded 6.65 +/- 0.69 and 0.32 +/- 0.07 mM, respectively, the portal-hepatic venous gradient became positive and increased linearly with portal concentrations. The glycogen concentration in the liver increased from a 22-h fast value of 5 mumol of glucosyl units/g wet weight to 101 +/- 7 mumol/g 2 h after the meal. The mean specific activity of portal vein plasma of [3-3H]glucose was 11,490 +/- 1,180 dpm/mumol (+/- S.E.) and that in the glycogen isolated from liver was 8,175 +/- 785 dpm/mumol of glycosyl units 2 h after the meal. The specific activity of liver [3H]glycogen relative to glucose after the meal was 0.73 +/- 0.08

  2. Early alterations in soleus GLUT-4, glucose transport, and glycogen in voluntary running rats

    Science.gov (United States)

    Henriksen, Erik J.; Halseth, Amy E.

    1994-01-01

    Voluntary wheel running (WR) by juvenile female rats was used as a noninterventional model of soleus muscle functional overload to study the regulation of insulin-stimulated glucose transport activity by the glucose transporter (GLUT-4 isoform) protein level and glycogen concentration. Soleus total protein content was significantly greater (+18%;P greater than 0.05) than in age-matched controls after 1 wk of WR, and this hypertrophic response continued in weeks 2-4 (+24-32%). GLUT-4 protein was 39% greater than in controls in 1-wk WR soleus, and this adaptation was accompanied by a similar increase in in vitro insulin-stimulated glucose transport activity(+29%). After 2 and 4 wk of WR, however, insulin-stimulated glucose transport activity had returned to control levels, despite a continued elevation (+25-28%) of GLUT-4 protein. At these two time points, glycogen concentration was significantly enhanced in WR soleus (+21-42%), which coincided with significant reductions in glycogen synthase activity ratios (-23 to-41%). These results indicate that, in this model of soleus muscle functional overload, the GLUT-4 protein level may initially regulate insulin-stimulated glucose transport activity in the absence of changes in other modifying factors. However,this regulation of glucose transport activity by GLUT-4 protein may be subsequently overridden by elevated glycogen concentration.

  3. Subcellular distribution of glycogen and decreased tetanic Ca2+ in fatigued single intact mouse muscle fibres

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Cheng, Arthur J; Ørtenblad, Niels; Westerblad, Hakan

    distribution by transmission electron microscopy. At fatigue, tetanic [Ca(2+)]i was reduced to 70 ± 4% and 54 ± 4% of the initial in HIF (P < 0.01, n = 9) and LIF (P < 0.01, n = 5) fibres, respectively. At fatigue, the mean inter- and intramyofibrillar glycogen content was 60-75% lower than in rested control...

  4. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT-4 content

    DEFF Research Database (Denmark)

    Asp, S; Rohde, T; Richter, Erik

    1997-01-01

    Our purpose was to investigate whether the slow rate of muscle glycogen resynthesis after a competitive marathon is associated with a decrease in the total muscle content of the muscle glucose transporter (GLUT-4). Seven well-trained marathon runners participated in the study, and muscle biopsies...

  5. FR258900, a potential anti-hyperglycemic drug, binds at the allosteric site of glycogen phosphorylase.

    Science.gov (United States)

    Tiraidis, Costas; Alexacou, Kyra-Melinda; Zographos, Spyros E; Leonidas, Demetres D; Gimisis, Thanasis; Oikonomakos, Nikos G

    2007-08-01

    FR258900 has been discovered as a novel inhibitor of human liver glycogen phosphorylase a and proved to suppress hepatic glycogen breakdown and reduce plasma glucose concentrations in diabetic mice models. To elucidate the mechanism of inhibition, we have determined the crystal structure of the cocrystallized rabbit muscle glycogen phosphorylase b-FR258900 complex and refined it to 2.2 A resolution. The structure demonstrates that the inhibitor binds at the allosteric activator site, where the physiological activator AMP binds. The contacts from FR258900 to glycogen phosphorylase are dominated by nonpolar van der Waals interactions with Gln71, Gln72, Phe196, and Val45' (from the symmetry-related subunit), and also by ionic interactions from the carboxylate groups to the three arginine residues (Arg242, Arg309, and Arg310) that form the allosteric phosphate-recognition subsite. The binding of FR258900 to the protein promotes conformational changes that stabilize an inactive T-state quaternary conformation of the enzyme. The ligand-binding mode is different from those of the potent phenoxy-phthalate and acyl urea inhibitors, previously described, illustrating the broad specificity of the allosteric site. PMID:17600143

  6. Effects of commonly used cryoprotectants on glycogen phosphorylase activity and structure.

    Science.gov (United States)

    Tsitsanou, K E; Oikonomakos, N G; Zographos, S E; Skamnaki, V T; Gregoriou, M; Watson, K A; Johnson, L N; Fleet, G W

    1999-04-01

    The effects of a number of cryoprotectants on the kinetic and structural properties of glycogen phosphorylase b have been investigated. Kinetic studies showed that glycerol, one of the most commonly used cryoprotectants in X-ray crystallographic studies, is a competitive inhibitor with respect to substrate glucose-1-P with an apparent Ki value of 3.8% (v/v). Cryogenic experiments, with the enzyme, have shown that glycerol binds at the catalytic site and competes with glucose analogues that bind at the catalytic site, thus preventing the formation of complexes. This necessitated a change in the conditions for cryoprotection in crystallographic binding experiments with glycogen phosphorylase. It was found that 2-methyl-2,4-pentanediol (MPD), polyethylene glycols (PEGs) of various molecular weights, and dimethyl sulfoxide (DMSO) activated glycogen phosphorylase b to different extents, by stabilizing its most active conformation, while sucrose acted as a noncompetitive inhibitor and ethylene glycol as an uncompetitive inhibitor with respect to glucose-1-P. A parallel experimental investigation by X-ray crystallography showed that, at 100 K, both MPD and DMSO do not bind at the catalytic site, do not induce any significant conformational change on the enzyme molecule, and hence, are more suitable cryoprotectants than glycerol for binding studies with glycogen phosphorylase. PMID:10211820

  7. RENAL-FUNCTION AND KIDNEY SIZE IN GLYCOGEN-STORAGE-DISEASE TYPE-I

    NARCIS (Netherlands)

    REITSMABIERENS, WCC; SMIT, GPA; TROELSTRA, JA

    1992-01-01

    Renal failure has been reported recently as a late complication of glycogen storage disease type I (GSD I). We studied the renal function of 23 patients, mean age 10.9 years (range 2.2-21.6 years). The mean glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were 188 +/- 50 and 9

  8. Muscle glycogen resynthesis during recovery from cycle exercise: no effect of additional protein ingestion

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Shirreffs, S M; Calbet, J A

    2000-01-01

    In the present study, we have investigated the effect of carbohydrate and protein hydrolysate ingestion on muscle glycogen resynthesis during 4 h of recovery from intense cycle exercise. Five volunteers were studied during recovery while they ingested, immediately after exercise, a 600-ml bolus and...

  9. Capsular glucan and intracellular glycogen of Mycobacterium tuberculosis: biosynthesis and impact on the persistence in mice

    DEFF Research Database (Denmark)

    Sambou, Tounkang; Dinadayala, Premkumar; Stadthagen, Gustavo; Barilone, Nathalie; Bordat, Yann; Constant, Patricia; Levillain, Florence; Neyrolles, Olivier; Gicquel, Brigitte; Lemassu, Anne; Daffé, Mamadou; Jackson, Mary

    2008-01-01

    Mycobacterium tuberculosis and other pathogenic mycobacterial species produce large amounts of a glycogen-like alpha-glucan that represents the major polysaccharide of their outermost capsular layer. To determine the role of the surface-exposed glucan in the physiology and virulence of these...

  10. Glycogen supercompensation masks the effect of a traininginduced increase in GLUT-4 on muscle glucose transport.

    Science.gov (United States)

    Host, H H; Hansen, P A; Nolte, L A; Chen, M M; Holloszy, J O

    1998-07-01

    Endurance exercise training induces a rapid increase in the GLUT-4 isoform of the glucose transporter in muscle. In fasted rats, insulin-stimulated muscle glucose transport is increased in proportion to the increase in GLUT-4. There is evidence that high muscle glycogen may decrease insulin-stimulated glucose transport. This study was undertaken to determine whether glycogen supercompensation interferes with the increase in glucose transport associated with an exercise-induced increase in GLUT-4. Rats were trained by means of swimming for 6 h/day for 2 days. Rats fasted overnight after the last exercise bout had an approximately twofold increase in epitrochlearis muscle GLUT-4 and an associated approximately twofold increase in maximally insulin-stimulated glucose transport activity. Epitrochlearis muscles of rats fed rodent chow after exercise were glycogen supercompensated (86.4 +/- 4.8 micromol/g wet wt) and showed no significant increase in maximally insulin-stimulated glucose transport above the sedentary control value despite an approximately twofold increase in GLUT-4. Fasting resulted in higher basal muscle glucose transport rates in both sedentary and trained rats but did not significantly increase maximally insulin-stimulated transport in the sedentary group. We conclude that carbohydrate feeding that results in muscle glycogen supercompensation prevents the increase in maximally insulin-stimulated glucose transport associated with an exercise training-induced increase in muscle GLUT-4. PMID:9655766

  11. Effects of depletion exercise and light training on muscle glycogen supercompensation in men.

    Science.gov (United States)

    Goforth, Harold W; Laurent, Didier; Prusaczyk, William K; Schneider, Kevin E; Petersen, Kitt Falk; Shulman, Gerald I

    2003-12-01

    Supercompensated muscle glycogen can be achieved by using several carbohydrate (CHO)-loading protocols. This study compared the effectiveness of two "modified" CHO-loading protocols. Additionally, we determined the effect of light cycle training on muscle glycogen. Subjects completed a depletion (D, n = 15) or nondepletion (ND, n = 10) CHO-loading protocol. After a 2-day adaptation period in a metabolic ward, the D group performed a 120-min cycle exercise at 65% peak oxygen uptake (VO2 peak) followed by 1-min sprints at 120% VO2 peak to exhaustion. The ND group performed only 20-min cycle exercise at 65% VO2 peak. For the next 6 days, both groups ate the same high-CHO diets and performed 20-min daily cycle exercise at 65% VO2 peak followed by a CHO beverage (105 g of CHO). Muscle glycogen concentrations of the vastus lateralis were measured daily with 13C magnetic resonance spectroscopy. On the morning of day 5, muscle glycogen concentrations had increased 1.45 (D) and 1.24 (ND) times baseline (P supercompensation. PMID:12902321

  12. Examination of methylphenidate-mediated behavior regulation by glycogen synthase kinase-3 in mice

    OpenAIRE

    Mines, Marjelo A.; Beurel, Eleonore; Jope, Richard S

    2012-01-01

    Abnormalities in dopaminergic activity have been implicated in psychiatric diseases, such as attention deficit hyperactivity disorder (ADHD), and are treated with therapeutic stimulants, commonly methylphenidate or amphetamine. Amphetamine administration increases glycogen synthase kinase-3 (GSK3) activation, which is necessary for certain acute behavioral responses to amphetamine, including increased locomotor activity and impaired sensorimotor gating. Here, we tested if modulating GSK3 by a...

  13. Reduced glycogen availability is associated with an elevation in HSP72 in contracting human skeletal muscle

    DEFF Research Database (Denmark)

    Febbraio, Mark A; Steensberg, Adam; Walsh, Rory;

    2002-01-01

    glycogen content was 40 % lower in the depleted compared with the control leg and this difference was maintained throughout the experiment (P < 0.05; main treatment effect). Neither HSP72 gene nor protein expression was different pre-exercise. However, both HSP72 gene and protein increased (P < 0.05) post...

  14. Monitoring of liver glycogen synthesis in diabetic patients using carbon-13 MR spectroscopy

    International Nuclear Information System (INIS)

    To investigate the relationship between liver glucose, glycogen, and plasma glucose in diabetic patients, in vivo liver carbon-13 magnetic resonance spectroscopy (13C MRS) with a clinical 3.0 T MR system was performed. Subjects were healthy male volunteers (n = 5) and male type-2 diabetic patients (n = 5). Pre- and during oral glucose tolerance tests (OGTT), 13C MR spectra without proton decoupling were acquired in a monitoring period of over 6 h, and in total seven spectra were obtained from each subject. For OGTT, 75 g of glucose, including 5 g of [1-13C]glucose, was administered. The MR signals of liver [1-13C]glucose and glycogen were detected and their time-course changes were assessed in comparison with the plasma data obtained at screening. The correlations between the fasting plasma glucose level and liver glycogen/glucose rate (Spearman: ρ = -0.68, p 13C MRS can perform noninvasive measurement of glycogen storage/degradation ability in the liver individually and can assist in tailor-made therapy for diabetes. In conclusion, 13C MRS has a potential to become a powerful tool in diagnosing diabetes multilaterally.

  15. Autophagy-assisted glycogen catabolism regulates asexual differentiation in Magnaporthe oryzae.

    Science.gov (United States)

    Deng, Yi Zhen; Ramos-Pamplona, Marilou; Naqvi, Naweed I

    2009-01-01

    Autophagy, a conserved pathway for bulk cellular degradation and recycling in eukaryotes, regulates proper turnover of organelles, membranes and certain proteins. Such regulated degradation is important for cell growth and development particularly during environmental stress conditions, which act as key inducers of autophagy. We found that autophagy and MoATG8 were significantly induced during asexual development in Magnaporthe oryzae. An RFP-tagged MoAtg8 showed specific localization and enrichment in aerial hyphae, conidiophores and conidia. We confirmed that loss of MoATG8 results in dramatically reduced ability to form conidia, the asexual spores that propagate rice-blast disease. Exogenous supply of glucose or sucrose significantly suppressed the conidiation defects in a MoATG8-deletion mutant. Comparative proteomics based identification and characterization of Gph1, a glycogen phosphorylase that catalyzes glycogen breakdown, indicated that autophagy-assisted glycogen homeostasis is likely important for proper aerial growth and conidiation in Magnaporthe. Loss of Gph1, or addition of G6P significantly restored conidiation in the Moatg8Delta mutant. Overproduction of Gph1 led to reduced conidiation in wild-type Magnaporthe strain. We propose that glycogen autophagy actively responds to and regulates carbon utilization required for cell growth and differentiation during asexual development in Magnaporthe. PMID:19115483

  16. Glycogen storage disease: report of two cases in the city of Cartagena

    Directory of Open Access Journals (Sweden)

    Ciro C. Alvear

    2010-03-01

    Full Text Available Objective: to report two cases of children with type Ia glycogen storage disease compatible with Von Gierke disease, suspected in the presence of findings such as hepatomegaly, nephromegaly, hypoglycemia, and stunted growth.Method: Presentation of the clinical records of two patients referred to the diagnostic unit of innate errors of metabolism of the Faculty of Medicine in Universidad de Cartagena.Results: The first case reported was a child who debuted with acute cyanosis without widespread neurological deficit when he was eleven months old, followed by hepatomegaly at two years of age. At 4 years of age, symptoms reappeared with similar characteristics: hypoglycemia, growth failure, and persistent hepatomegaly detected on physical examination. With the precedent that an older brother that presented similar symptoms was suspected of glycogen storage disease, a biopsy was performed and confirmed liver glycogen storage with normal structure. The patient’s treatment was modification of dietary habits (small, frequent feedings during the day and cornstarch. The second event was the older brother who consulted for the first time when he was 18 months old due to prolonged diarrhea. Hepatomegaly was documented by ultrasound study without kidney compromise and no hypoglycemia was found.Recommendations: It is necessary for the entire health team to be trained to detect rare diseases such as glycogen storage disease. If they make early diagnoses and establish support groups for interdisciplinary management of such diseases, they may change the prognosis and quality of life of these children.

  17. Glycogen storage disease: report of two cases in the city of Cartagena

    Directory of Open Access Journals (Sweden)

    Ciro C. Alvear

    2010-09-01

    Full Text Available Objective: to report two cases of children with type Ia glycogen storage disease compatible with Von Gierke disease, suspected in the presence of findings such as hepatomegaly, nephromegaly, hypoglycemia, and stunted growth. Method: Presentation of the clinical records of two patients referred to the diagnostic unit of innate errors of metabolism of the Faculty of Medicine in Universidad de Cartagena. Results: The first case reported was a child who debuted with acute cyanosis without widespread neurological deficit when he was eleven months old, followed by hepatomegaly at two years of age. At 4 years of age, symptoms reappeared with similar characteristics: hypoglycemia, growth failure, and persistent hepatomegaly detected on physical examination. With the precedent that an older brother that presented similar symptoms was suspected of glycogen storage disease, a biopsy was performed and confirmed liver glycogen storage with normal structure. The patient’s treatment was modification of dietary habits (small, frequent feedings during the day and cornstarch. The second event was the older brother who consulted for the first time when he was 18 months old due to prolonged diarrhea. Hepatomegaly was documented by ultrasound study without kidney compromise and no hypoglycemia was found. Recommendations: It is necessary for the entire health team to be trained to detect rare diseases such as glycogen storage disease. If they make early diagnoses and establish support groups for interdisciplinary management of such diseases, they may change the prognosis and quality of life of these children.

  18. A patient with common glycogen storage disease type Ib mutations without neutropenia or neutrophil dysfunction

    NARCIS (Netherlands)

    Martens, DHJ; Kuijpers, TW; Maianski, NA; Rake, JP; Smit, GPA; Visser, G

    2006-01-01

    We describe a 16-year old boy with glycogen storage disease type Ib, homozygous for the common 1211-1212delCT mutation, who never experienced neutropenia, and did not suffer from frequent infections or inflammatory bowel disease. In addition, neutrophil function tests showed no abnormalities.

  19. Glucose balance and muscle glycogen during TPN in the early post-operative phase

    DEFF Research Database (Denmark)

    Henneberg, S; Stjernström, H; Essén-Gustavsson, B; Wiklund, L

    1985-01-01

    -production) were performed and from these data glucose balance was calculated as the difference between glucose intake and glucose expenditure. Muscle biopsies were analysed for glycogen, adenosine triphosphate, glucose-6-phosphate, lactate and citrate. We found that it was possible to maintain muscle...

  20. Glycogen synthase kinase 3α and 3β have distinct functions during cardiogenesis of zebrafish embryo

    Directory of Open Access Journals (Sweden)

    Sun Chi-Kuang

    2007-08-01

    Full Text Available Abstract Background Glycogen synthase kinase 3 (GSK3 encodes a serine/threonine protein kinase, is known to play roles in many biological processes. Two closely related GSK3 isoforms encoded by distinct genes: GSK3α (51 kDa and GSK3β (47 kDa. In previously studies, most GSK3 inhibitors are not only inhibiting GSK3, but are also affecting many other kinases. In addition, because of highly similarity in amino acid sequence between GSK3α and GSK3β, making it difficult to identify an inhibitor that can be selective against GSK3α or GSK3β. Thus, it is relatively difficult to address the functions of GSK3 isoforms during embryogenesis. At this study, we attempt to specifically inhibit either GSK3α or GSK3β and uncover the isoform-specific roles that GSK3 plays during cardiogenesis. Results We blocked gsk3α and gsk3β translations by injection of morpholino antisense oligonucleotides (MO. Both gsk3α- and gsk3β-MO-injected embryos displayed similar morphological defects, with a thin, string-like shaped heart and pericardial edema at 72 hours post-fertilization. However, when detailed analysis of the gsk3α- and gsk3β-MO-induced heart defects, we found that the reduced number of cardiomyocytes in gsk3α morphants during the heart-ring stage was due to apoptosis. On the contrary, gsk3β morphants did not exhibit significant apoptosis in the cardiomyocytes, and the heart developed normally during the heart-ring stage. Later, however, the heart positioning was severely disrupted in gsk3β morphants. bmp4 expression in gsk3β morphants was up-regulated and disrupted the asymmetry pattern in the heart. The cardiac valve defects in gsk3β morphants were similar to those observed in axin1 and apcmcr mutants, suggesting that GSK3β might play a role in cardiac valve development through the Wnt/β-catenin pathway. Finally, the phenotypes of gsk3α mutant embryos cannot be rescued by gsk3β mRNA, and vice versa, demonstrating that GSK3α and GSK3β are

  1. The influence of free fatty acids on glycogen recovery in rat heart after exercise.

    Science.gov (United States)

    Conlee, R K; Dalsky, G P; Robinson, K C

    1981-01-01

    Glycogen supercompensation is the term used to denote the abnormally high levels of glycogen found in the heart shortly after an exercise-induced reduction of the substrate. Using rats, we tested whether this condition was linked to the use of plasma free fatty acids (FFA), which normally rise with exercise. Before a 1-h swim, animals received an injection of either saline (S) or nicotinic acid (NA). The nicotinic acid treatment dramatically suppressed the rise in plasma FFA observed in the S-group. Exercise caused a significant but similar reduction (35-38%) of the myocardial glycogen content in both groups. After 1 h of recovery in the S-group, myocardial glycogen reached a value of 30.3 +/- 1.7 mumol x g-1 or 113% of that measured before the exercise began. In contrast, the value for hearts from the NA-group with reduced FFA levels was 24.0 +/- 1.9 mumol x g-1 or only 91% of that measured before exercise. After 2 h the values were 33.8 +/- 1.4 and 29.0 +/- 1.9 mumol x g-1 respectively. These data indicate that glycogen repletion in rat heart after exercise is related to the amount of FFA present in the plasma. We suggest that carbohydrate metabolism is diverted towards synthesis and storage as a result of the glycolytic inhibition exerted by the increased use of fat as an energy source as previously observed in hearts from fasted or diabetic animals. PMID:7199440

  2. Lowering Temperature is the Trigger for Glycogen Build-Up and Winter Fasting in Crucian Carp (Carassius carassius).

    Science.gov (United States)

    Varis, Joonas; Haverinen, Jaakko; Vornanen, Matti

    2016-02-01

    Seasonal changes in physiology of vertebrate animals are triggered by environmental cues including temperature, day-length and oxygen availability. Crucian carp (Carassius carassius) tolerate prolonged anoxia in winter by using several physiological adaptations that are seasonally activated. This study examines which environmental cues are required to trigger physiological adjustments for winter dormancy in crucian carp. To this end, crucian carp were exposed to changing environmental factors under laboratory conditions: effects of declining water temperature, shortening day-length and reduced oxygen availability, separately and in different combinations, were examined on glycogen content and enzyme activities involved in feeding (alkaline phosphatase, AP) and glycogen metabolism (glycogen synthase, GyS; glycogen phosphorylase, GP). Lowering temperature induced a fall in activity of AP and a rise in glycogen content and rate of glycogen synthesis. Relative mass of the liver, and glycogen concentration of liver, muscle and brain increased with lowering temperature. Similarly activity of GyS in muscle and expression of GyS transcripts in brain were up-regulated by lowering temperature. Shortened day-length and oxygen availability had practically no effects on measured variables. We conclude that lowering temperature is the main trigger in preparation for winter anoxia in crucian carp. PMID:26853873

  3. Glucose analogue inhibitors of glycogen phosphorylase: from crystallographic analysis to drug prediction using GRID force-field and GOLPE variable selection.

    Science.gov (United States)

    Watson, K A; Mitchell, E P; Johnson, L N; Cruciani, G; Son, J C; Bichard, C J; Fleet, G W; Oikonomakos, N G; Kontou, M; Zographos, S E

    1995-07-01

    Several inhibitors of the large regulatory enzyme glycogen phosphorylase (GP) have been studied in crystallographic and kinetic experiments. GP catalyses the first step in the phosphorylysis of glycogen to glucose-l-phosphate, which is utilized via glycolysis to provide energy to sustain muscle contraction and in the liver is converted to glucose. alpha-D-Glucose is a weak inhibitor of glycogen phosphorylase form b (GPb, K(i) = 1.7 mM) and acts as a physiological regulator of hepatic glycogen metabolism. Glucose binds to phosphorylase at the catalytic site and results in a conformational change that stabilizes the inactive T state of the enzyme, promoting the action of protein phosphatase 1 and stimulating glycogen synthase. It has been suggested that in the liver, glucose analogues with greater affinity for glycogen phosphorylase may result in a more effective regulatory agent. Several N-acetyl glucopyranosylamine derivatives have been synthesized and tested in a series of crystallographic and kinetic binding studies with GPb. The structural results of the bound enzyme-ligand complexes have been analysed together with the resulting affinities in an effort to understand and exploit the molecular interactions that might give rise to a better inhibitor. Comparison of the N-methylacetyl glucopyranosylamine (N-methylamide, K(i) = 0.032 mM) with the analogous beta-methylamide derivative (C-methylamide, K(i) = 0.16 mM) illustrate the importance of forming good hydrogen bonds and obtaining complementarity of van der Waals interactions. These studies also have shown that the binding modes can be unpredictable but may be rationalized with the benefit of structural data and that a buried and mixed polar/non-polar catalytic site poses problems for the systematic addition of functional groups. Together with previous studies of glucose analogue inhibitors of GPb, this work forms the basis of a training set suitable for three-dimensional quantitative structure

  4. Financial Literacy, Schooling, and Wealth Accumulation

    OpenAIRE

    Behrman, Jere R.; Mitchell, Olivia S.; Cindy Soo; David Bravo

    2010-01-01

    Financial literacy and schooling attainment have been linked to household wealth accumulation. Yet prior findings may be biased due to noisy measures of financial literacy and schooling, as well as unobserved factors such as ability, intelligence, and motivation that could enhance financial literacy and schooling but also directly affect wealth accumulation. We use a new household dataset and an instrumental variables approach to isolate the causal effects of financial literacy and schooling ...

  5. Microbial accumulation of uranium, radium, and cesium

    International Nuclear Information System (INIS)

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested

  6. The effects of glycogen synthase kinase-3beta in serotonin neurons.

    Directory of Open Access Journals (Sweden)

    Wenjun Zhou

    Full Text Available Glycogen synthase kinase-3 (GSK3 is a constitutively active protein kinase in brain. Increasing evidence has shown that GSK3 acts as a modulator in the serotonin neurotransmission system, including direct interaction with serotonin 1B (5-HT1B receptors in a highly selective manner and prominent modulating effect on 5-HT1B receptor activity. In this study, we utilized the serotonin neuron-selective GSK3β knockout (snGSK3β-KO mice to test if GSK3β in serotonin neurons selectively modulates 5-HT1B autoreceptor activity and function. The snGSK3β-KO mice were generated by crossbreeding GSK3β-floxed mice and ePet1-Cre mice. These mice had normal growth and physiological characteristics, similar numbers of tryptophan hydroxylase-2 (TpH2-expressing serotonin neurons, and the same brain serotonin content as in littermate wild type mice. However, the expression of GSK3β in snGSK3β-KO mice was diminished in TpH2-expressing serotonin neurons. Compared to littermate wild type mice, snGSK3β-KO mice had a reduced response to the 5-HT1B receptor agonist anpirtoline in the regulation of serotonergic neuron firing, cAMP production, and serotonin release, whereas these animals displayed a normal response to the 5-HT1A receptor agonist 8-OH-DPAT. The effect of anpirtoline on the horizontal, center, and vertical activities in the open field test was differentially affected by GSK3β depletion in serotonin neurons, wherein vertical activity, but not horizontal activity, was significantly altered in snGSK3β-KO mice. In addition, there was an enhanced anti-immobility response to anpirtoline in the tail suspension test in snGSK3β-KO mice. Therefore, results of this study demonstrated a serotonin neuron-targeting function of GSK3β by regulating 5-HT1B autoreceptors, which impacts serotonergic neuron firing, serotonin release, and serotonin-regulated behaviors.

  7. Distinct effects of subcellular glycogen localization on tetanic relaxation time and endurance in mechanically skinned rat skeletal muscle fibres

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Schrøder, H D; Rix, C G;

    2009-01-01

    by transmission electron microscopy. The other segment was mechanically skinned and, in the presence of high and constant myoplasmic ATP and PCr, electrically stimulated (10 Hz, 0.8 s every 3 s) eliciting repeated tetanic contractions until the force response was decreased by 50% (mean +/- S.E.M., 81 +/- 16......In vitro experiments indicate a non-metabolic role of muscle glycogen in contracting skeletal muscles. Since the sequence of events in excitation\\#8211;contraction (E\\#8211;C) coupling is known to be located close to glycogen granules, at specific sites on the fibre, we hypothesized......, range 22-252 contractions). Initially the total myofibrillar glycogen volume percentage was 0.46 +/- 0.07%, with 72 +/- 3% in the intermyofibrillar space and 28 +/- 3% in the intramyofibrillar space. The intramyofibrillar glycogen content was positively correlated with the fatigue resistance capacity (r...

  8. Muscle and liver glycogen, protein, and triglyceride in the rat. Effect of exercise and of the sympatho-adrenal system

    DEFF Research Database (Denmark)

    Richter, E A; Sonne, B; Mikines, K J;

    1984-01-01

    We have previously found that during exercise net muscle glycogen breakdown is impaired in adrenodemedullated rats, as compared with controls. The present study was carried out to elucidate whether, in rats with deficiencies of the sympatho-adrenal system, diminished exercise-induced glycogenolysis...... decrease. In exercising rats, muscle glycogen breakdown was impaired by adrenodemedullation and restored by infusion of epinephrine. However, impaired glycogen breakdown during exercise was not accompanied by a significant net breakdown of protein or triglyceride. Surgical sympathectomy of the muscles did...... in skeletal muscle was accompanied by increased breakdown of triglyceride and/or protein. Thus, the effect of exhausting swimming and of running on concentrations of glycogen, protein, and triglyceride in skeletal muscle and liver were studied in rats with and without deficiencies of the sympatho...

  9. Sunflower plants nutrients accumulation and oil yield as affected by achenes vigour and sowing density
    Acúmulo de nutrientes e rendimento de óleo em plantas de girassol influenciados pelo vigor dos aquênios e pela densidade de semeadura

    OpenAIRE

    Madelon Rodrigues Sá Braz; Claudia Antônia Vieira Rossetto

    2010-01-01

    The objective this work was to evaluate the nutrients accumulation and achenes oil yield in sunflower plants as affected by achenes vigour and sowing density. An experiment was installed in the field at Seropédica, State of Rio de Janeiro, in October 2006 with three lots of sunflower achenes, cultivar Embrapa 122 V2000, classified as low, medium and high vigour and two sowing density (45,000 e 75,000 seeds.ha-1). The collected were realized at 20, 60 and 100 days after planting (DAP) to the d...

  10. Differences in glycogen, lipids, and enzymes in livers from rats flown on Cosmos 2044

    Science.gov (United States)

    Merrill, Alfred H., Jr.; Wang, Elaine; Laroque, Regina; Mullins, Richard E.; Morgan, Edward T.; Hargrove, James L.; Bonkovsky, Herbert L.; Popova, Irina A.

    1992-01-01

    Livers from rats flown aboard Cosmos 2044 were analyzed for protein, carbohydrate (glycogen), and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. The major differences between the flight group and the synchronous control were elevations in microsomal protein, liver glycogen content, tyrosine aminotransferase, and tryptophan oxygenase and reductions in sphingolipids and the rate-limiting enzyme of heme biosynthesis delta-aminolevulinic acid synthase. These results provide further evidence that spaceflight has pronounced and diverse effects on liver function; however, some of the results with samples from Cosmos 2044 differed notably from those from previous spaceflights. This may be due to conditions of spaceflight and/or the postflight recovery period for Cosmos 2044.

  11. Butyrate ingestion improves hepatic glycogen storage in the re-fed rat

    Directory of Open Access Journals (Sweden)

    Rigalleau Vincent

    2008-10-01

    Full Text Available Abstract Background Butyrate naturally produced by intestinal fiber fermentation is the main nutrient for colonocytes, but the metabolic effect of the fraction reaching the liver is not totally known. After glycogen hepatic depletion in the 48-hour fasting rat, we monitored the effect of (butyrate 1.90 mg + glucose 14.0 mg/g body weight versus isocaloric (glucose 18.2 mg/g or isoglucidic (glucose 14.0 mg/g control force-feeding on in vivo changes in hepatic glycogen and ATP contents evaluated ex vivo by NMR in the isolated and perfused liver. Results The change in glycogen was biphasic with (i an initial linear period where presence of butyrate in the diet increased (P = 0.05 the net synthesis rate (0.20 ± 0.01 μmol/min.g-1 liver wet weight, n = 15 versus glucose 14.0 mg/g only (0.16 ± 0.01 μmol/min.g-1 liver ww, n = 14, and (ii a plateau of glycogen store followed by a depletion. Butyrate delayed the establishment of the equilibrium between glycogenosynthetic and glycogenolytic fluxes from the 6th to 8th hour post-feeding. The maximal glycogen content was then 97.27 ± 10.59 μmol/g liver ww (n = 7 at the 8th hour, which was significantly higher than with the isocaloric control diet (64.34 ± 8.49 μmol/g, n = 12, P = 0.03 and the isoglucidic control one (49.11 ± 6.35 μmol/g liver ww, n = 6, P = 0.003. After butyrate ingestion, ATP content increased from 0.95 ± 0.29 to a plateau of 2.14 ± 0.23 μmol/g liver ww at the 8th hour post-feeding (n = 8 [P = 0.04 versus isoglucidic control diet (1.45 ± 0.19 μmol/g, n = 8 but was not different from the isocaloric control diet (1.70 ± 0.18 μmol/g, n = 12]. Conclusion The main hepatic effect of butyrate is a sparing effect on glycogen storage explained (i by competition between butyrate and glucose oxidation, glucose being preferentially directed to glycogenosynthesis during the post-prandial state; and (ii by a likely reduced glycogenolysis from the newly synthesized glycogen. This first

  12. An efficient nonviral gene-delivery vector based on hyperbranched cationic glycogen derivatives

    Directory of Open Access Journals (Sweden)

    Liang X

    2014-01-01

    Full Text Available Xuan Liang,1,* Xianyue Ren,2,* Zhenzhen Liu,1 Yingliang Liu,1 Jue Wang,2 Jingnan Wang,2 Li-Ming Zhang,1 David YB Deng,2 Daping Quan,1 Liqun Yang1 1Institute of Polymer Science, School of Chemistry and Chemical Engineering, Key Laboratory of Designed Synthesis and Application of Polymer Material, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen University, Guangzhou, People's Republic of China; 2Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China *Both these authors contributed equally to this work Background: The purpose of this study was to synthesize and evaluate hyperbranched cationic glycogen derivatives as an efficient nonviral gene-delivery vector. Methods: A series of hyperbranched cationic glycogen derivatives conjugated with 3-(dimethylamino-1-propylamine (DMAPA-Glyp and 1-(2-aminoethyl piperazine (AEPZ-Glyp residues were synthesized and characterized by Fourier-transform infrared and hydrogen-1 nuclear magnetic resonance spectroscopy. Their buffer capacity was assessed by acid–base titration in aqueous NaCl solution. Plasmid deoxyribonucleic acid (pDNA condensation ability and protection against DNase I degradation of the glycogen derivatives were assessed using agarose gel electrophoresis. The zeta potentials and particle sizes of the glycogen derivative/pDNA complexes were measured, and the images of the complexes were observed using atomic force microscopy. Blood compatibility and cytotoxicity were evaluated by hemolysis assay and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, respectively. pDNA transfection efficiency mediated by the cationic glycogen derivatives was evaluated by flow cytometry and fluorescence microscopy in the 293T (human embryonic kidney and the CNE2 (human nasopharyngeal carcinoma cell lines. In vivo delivery of pDNA in model animals (Sprague Dawley

  13. Pathways of hepatic glycogen formation in humans following ingestion of a glucose load in the fed state

    International Nuclear Information System (INIS)

    The relative contributions of the direct and the indirect pathways to hepatic glycogen formation following a glucose load given to humans four hours after a substantial breakfast have been examined. Glucose loads labeled with [6-(14)C]glucose were given to six healthy volunteers along with diflunisal (1 g) or acetaminophen (1.5 g), drugs excreted in urine as glucuronides. Distribution of 14C in the glucose unit of the glucuronide was taken as a measure of the extent to which glucose was deposited directly in liver glycogen (ie, glucose----glucose-6-phosphate----glycogen) rather than indirectly (ie, glucose----C3-compound----glucose-6-phosphate----glycogen). The maximum contribution to glycogen formation by the direct pathway was estimated to be 77% +/- 4%, which is somewhat higher than previous estimates in humans fasted overnight (65% +/- 1%, P less than 0.05). Thus, the indirect pathway of liver glycogen formation following a glucose load is operative in both the overnight fasted and the fed state, although its contribution may be somewhat less in the fed state

  14. Beta-endorphin infusion during exercise in rats does not alter hepatic or muscle glycogen.

    Science.gov (United States)

    Jamurtas, A Z; Goldfarb, A H; Chung, S C; Hegde, S; Marino, C; Fatouros, I G

    2001-12-01

    The aim of this study was to determine whether beta-endorphin infusion influences liver or muscle glycogen concentration during exercise. Thirty-two rats (Harlan Co., IN, USA) with a body mass of 265-290 g were assigned at random to four groups, each of eight rats: (1) beta-endorphin infusion for 90 min at rest; (2) beta-endorphin infusion for 90 min while running on a rodent treadmill at 22 m x min(-1) and 0% grade; (3) saline infusion (0.9% NaCl) for 90 min at rest; and (4) saline infusion for 90 min while running on a rodent treadmill at 22 m x min(-1) and 0% grade. Beta-endorphin infusion elevated plasma beta-endorphin concentration by 2.5-fold at rest compared with saline infusion at rest, and by two-fold after exercise compared with saline infusion after exercise. Beta-endorphin infusion attenuated exercise-induced glucose concentration but did not alter the fasting hepatic glycogen concentration at rest or after exercise compared with saline infusion. Fasting hepatic glycogen decreased significantly as a result of 90 min of exercise independent of treatment. Deep intermedius muscle glycogen concentration at rest was similar after 90 min of both beta-endorphin and saline infusion and decreased significantly as a result of 90 min of exercise independent of treatment. Our results suggest that liver and muscle glycogenolysis is not responsible for the differences in plasma glucose with beta-endorphin infusion during exercise. PMID:11820687

  15. Clinical study of respiratory function in patients with late-onset glycogen storage disease typeⅡ

    Directory of Open Access Journals (Sweden)

    Wei-na JIN

    2014-05-01

    Full Text Available Background Late-onset glycogen storage disease typeⅡ(GSDⅡ, Pompe disease is an autosomal recessive disease exhibiting progressive proximal skeletal muscle weakness and respiratory muscle involvement, caused by deficiency of the lysosomal enzyme acid α-glucosidase (GAA. Most of patients died of respiratory failure.  Methods Eleven patients with late-onset glycogen storage disease type Ⅱ underwent respiratory function evaluation, whose diagnosis was confirmed by muscle pathology, GAA activity assay and gene analysis. Respiratory function evaluation included upright and supine position of forced vital capacity (FVC, forced expiratory volume at the first second (FEV1, maximal inspiratory pressure (MIP, maximal expiratory pressure (MEP and cough peak flow (CPF. All data were compared with predicted value. The decreased value between upright and supine position FVC ( △ FVC were calculated. The correlation between respiratory function and the age of onset, disease course, motor function, GAA activity were analyzed.  Results All of 11 patients with late-onset glycogen storage disease type Ⅱ showed declined respiratory function compared with predicted value. The upright FVC, upright FEV1, △ FVC, MIP, MEP and CPF declined in 10, 10, 8, 11, 10, and 10 patients, respectively. All patients had normal FEV1/FVC in both upright and supine position. There was no correlation between upright FVC, △ FVC and the onset age, disease course, motor function, GAA activity statistically.  Conclusions Pulmonary dysfunction is common in late-onset glycogen storage disease type Ⅱ, with restrictive ventilatory impairment more predominant, which is caused by inspiratory muscle weakness. doi: 10.3969/j.issn.1672-6731.2014.05.007

  16. Glycogen synthase kinase-3 in the etiology and treatment of mood disorders

    OpenAIRE

    Richard Scott Jope

    2011-01-01

    The mood disorders major depressive disorder and bipolar disorder are prevalent, are inadequately treated, and little is known about their etiologies. A better understanding of the causes of mood disorders would benefit from improved animal models of mood disorders, which now rely on behavioral measurements. This review considers the limitations in relating measures of rodent behaviors to mood disorders, and the evidence from behavioral assessments indicating that glycogen synthase kinase-3 (...

  17. Glycogen Synthase Kinase-3 in the Etiology and Treatment of Mood Disorders

    OpenAIRE

    Jope, Richard Scott

    2011-01-01

    The mood disorders major depressive disorder and bipolar disorder are prevalent, are inadequately treated, and little is known about their etiologies. A better understanding of the causes of mood disorders would benefit from improved animal models of mood disorders, which now rely on behavioral measurements. This review considers the limitations in relating measures of rodent behaviors to mood disorders, and the evidence from behavioral assessments indicating that glycogen synthase kinase-3 (...

  18. Regulation of Th1 cells and experimental autoimmune encephalomyelitis (EAE) by glycogen synthase kinase-3

    OpenAIRE

    Beurel, Eléonore; Kaidanovich-Beilin, Oksana; Yeh, Wen-I; Song, Ling; Palomo, Valle; Michalek, Suzanne M.; Woodgett, James R.; Harrington, Laurie E.; Eldar-Finkelman, Hagit; Martinez, Ana; Jope, Richard S.

    2013-01-01

    Experimental autoimmune encephalomyelitis (EAE) is a rodent model of multiple sclerosis (MS), a debilitating autoimmune disease of the central nervous system, for which only limited therapeutic interventions are available. Since MS is mediated in part by autoreactive T cells, particularly Th17 and Th1 cells, in the present study, we tested if inhibitors of glycogen synthase kinase-3 (GSK3), previously reported to reduce Th17 cell generation, also alter Th1 cell production or ameliorate EAE. G...

  19. Effects of commonly used cryoprotectants on glycogen phosphorylase activity and structure.

    OpenAIRE

    Tsitsanou, K. E.; Oikonomakos, Nikos G.; Zographos, Spyros E.; Skamnaki, V. T.; Gregoriou, M; Watson, K. A.; Johnson, L N; Fleet, G. W. J.

    1999-01-01

    The effects of a number of cryoprotectants on the kinetic and structural properties of glycogen phosphorylase b have been investigated. Kinetic studies showed that glycerol, one of the most commonly used cryoprotectants in X-ray crystallographic studies, is a competitive inhibitor with respect to substrate glucose-1-P with an apparent Ki value of 3.8% (v/v). Cryogenic experiments, with the enzyme, have shown that glycerol binds at the catalytic site and competes with glucose analogues that bi...

  20. Overexpression of Glycogen Synthase Kinase 3β Sensitizes Neuronal Cells to Ethanol Toxicity

    OpenAIRE

    Liu, Ying(College of Nuclear Science and Technology, Beijing Normal University, 100875, Beijing, China); Chen, Gang; Ma, Cuiling; Bower, Kimberly A.; Xu, Mei; Fan, Zhiqin; Shi, Xianglin; Ke, Zun-Ji; Luo, Jia

    2009-01-01

    The developing central nervous system (CNS) is particularly susceptible to ethanol toxicity. The loss of neurons underlies many of the behavioral deficits observed in fetal alcohol spectrum disorders (FASD). The mechanisms of ethanol-induced neuronal loss, however, remain incompletely elucidated. We demonstrated that glycogen synthase kinase 3β (GSK3β), a multifunctional serine/threonine kinase, was involved in ethanol neurotoxicity. The activity of GSK3β is negatively regulated by its phosph...

  1. Dietary Tools To Modulate Glycogen Storage In Fish Muscle: A Proteomic Assessment

    OpenAIRE

    Silva, Tomé S.; Matos, Elisabete; Cordeire, Odete; Wulff, Tune; Goncalves, Amparo; Nunes, Maria Leonor; Dias, Jorge; Jessen, Flemming; Rodrigues, Pedro M.

    2011-01-01

    Post-mortem flesh deterioration is dependent on the energy reserves present at the time of death. Early depletion of muscle glycogen leads to the buildup of lactate and to the early onset of rigor mortis, resulting in the activation of endogenous proteases and the degradation of myofibrillar proteins, and consequent muscle softening. The purpose of this study was to modulate the energy status of the muscle at the time of death through the use of dietary muscle buffering compounds, namely glyc...

  2. Effect of glycogen synthase kinase-3 inactivation on mouse mammary gland development and oncogenesis

    OpenAIRE

    Dembowy, J; Adissu, H A; Liu, J. C.; Zacksenhaus, E; Woodgett, J R

    2014-01-01

    Many components of the Wnt/β-catenin signaling pathway have critical functions in mammary gland development and tumor formation, yet the contribution of glycogen synthase kinase-3 (GSK-3α and GSK-3β) to mammopoiesis and oncogenesis is unclear. Here, we report that WAP-Cre-mediated deletion of GSK-3 in the mammary epithelium results in activation of Wnt/β-catenin signaling and induces mammary intraepithelial neoplasia that progresses to squamous transdifferentiation and development of adenosqu...

  3. Glycogen synthase kinase 3 beta: can it be a target for oral cancer

    OpenAIRE

    Mishra Rajakishore

    2010-01-01

    Abstract Despite progress in treatment approaches for oral cancer, there has been only modest improvement in patient outcomes in the past three decades. The frequent treatment failure is due to the failure to control tumor recurrence and metastasis. These failures suggest that new targets should be identified to reverse oral epithelial dysplastic lesions. Recent developments suggest an active role of glycogen synthase kinase 3 beta (GSK3 β) in various human cancers either as a tumor suppresso...

  4. Functional Role of Glycogen synthase Kinase-3β on Glucocorticoid-mediated signaling

    OpenAIRE

    Rubio Patiño, Camila

    2012-01-01

    Glucocorticoids (GC) induce cell cycle arrest and apoptosis in different cell types and therefore are widely used to treat a variety of diseases including autoimmune disorders and cancer. This effect is mediated by the GC receptor (GR), a ligandactivated transcription factor that translocates into the nucleus where it modulates transcription of target genes in a promoter-specific manner. Glycogen synthase kinase-3 (GSK3) regulates GR response by genomic and nongenomic mechanisms, although the...

  5. Progress in Enzyme Replacement Therapy in Glycogen Storage Disease Type II

    OpenAIRE

    Angelini, Corrado; SEMPLICINI, CLAUDIO; Tonin, Paola; Filosto, Massimiliano; Pegoraro, Elena; Sorarù, Gianni; Fanin, Marina

    2009-01-01

    Glycogen storage disease type II (GSDII) is an autosomal recessive lysosomal disorder caused by mutations in the gene encoding alpha-glucosidase (GAA). The disease can be clinically classified into three types: a severe infantile form, a juvenile and an adultonset form. Cases with juvenile or adult onset GSDII mimic limb-girdle muscular dystrophy or polymyositis and are often characterized by respiratory involvement. GSDII patients are diagnosed by biochemical assay and by m...

  6. Disordered Eating and Body Esteem Among Individuals with Glycogen Storage Disease

    OpenAIRE

    Flanagan, Theresa B.; Sutton, Jill A.; Brown, Laurie M.; Weinstein, David A.; Merlo, Lisa J.

    2015-01-01

    Glycogen storage disease (GSD) is an inherited disorder that requires a complex medical regimen to maintain appropriate metabolic control. Previous research has suggested the disease is associated with decreased quality of life, and clinical experience suggests that patients are at risk for disordered eating behaviors that may significantly compromise their health. The current study assessed eating attitudes, eating disorder symptoms, and body image among 64 patients with GSD ranging from 7–5...

  7. The binding of 2-deoxy-D-glucose 6-phosphate to glycogen phosphorylase b: kinetic and crystallographic studies.

    Science.gov (United States)

    Oikonomakos, N G; Zographos, S E; Johnson, L N; Papageorgiou, A C; Acharya, K R

    1995-12-15

    Kinetic and crystallographic studies have characterized the effect of 2-deoxy-glucose 6-phosphate on the catalytic and structural properties of glycogen phosphorylase b. Previous work on the binding of glucose 6-phosphate, a potent physiological inhibitor of the enzyme, to T state phosphorylase b in the crystal showed that the inhibitor binds at the allosteric site and induces substantial conformational changes that affect the subunit-subunit interface. The hydrogen-bond from the O-2 hydroxyl of glucose 6-phosphate to the main-chain oxygen of Val40' represents the only hydrogen bond from the sugar to the other subunit, and this interaction appears important for promoting a more "tensed" structure than native T state phosphorylase b. 2-Deoxy-glucose 6-phosphate acts competitively with both the activator AMP and the substrate glucose 1-phosphate, with Ki values of 0.53 mM and 1.23 mM, respectively. The binding of 2-deoxy-glucose 6-phosphate to T state glycogen phosphorylase b in the crystal, has been investigated and the complex phosphorylase b: 2-deoxy-glucose 6-phosphate has been refined to give a crystallographic R factor of 17.3%, for data between 8 A and 2.3 A. 2-Deoxy-glucose 6-phosphate binds at the allosteric site as the a anomer and adopts a different conformation compared to glucose 6-phosphate. The two conformations differ by 160 degrees in the torsion angle about the C-5-C-6 bond. The contacts from the phosphate group are essentially identical to those made by the phosphate of glucose 6-phosphate but the 2-deoxy glucosyl moiety binds in a quite different orientation compared to the glucosyl of glucose 6-phosphate. 2-Deoxy-glucose 6-phosphate can be accommodated in the allosteric site with very little change in the protein, while structural comparisons show that the phosphorylase b: 2-deoxy-glucose 6-phosphate complex structure is overall more similar to a glucose-like complex than to the Glc-6-P complex structure. PMID:7500360

  8. Inhibition of glycogen synthase kinase-3β attenuates glucocorticoid-induced suppression of myogenic differentiation in vitro.

    Directory of Open Access Journals (Sweden)

    Zhenyu Ma

    Full Text Available Glucocorticoids are the only therapy that has been demonstrated to alter the progress of Duchenne muscular dystrophy (DMD, the most common muscular dystrophy in children. However, glucocorticoids disturb skeletal muscle metabolism and hamper myogenesis and muscle regeneration. The mechanisms involved in the glucocorticoid-mediated suppression of myogenic differentiation are not fully understood. Glycogen synthase kinase-3β (GSK-3β is considered to play a central role as a negative regulator in myogenic differentiation. Here, we showed that glucocorticoid treatment during the first 48 h in differentiation medium decreased the level of phosphorylated Ser9-GSK-3β, an inactive form of GSK-3β, suggesting that glucocorticoids affect GSK-3β activity. We then investigated whether GSK-3β inhibition could regulate glucocorticoid-mediated suppression of myogenic differentiation in vitro. Two methods were employed to inhibit GSK-3β: pharmacological inhibition with LiCl and GSK-3β gene knockdown. We found that both methods resulted in enhanced myotube formation and increased levels of muscle regulatory factors and muscle-specific protein expression. Importantly, GSK-3β inhibition attenuated glucocorticoid-induced suppression of myogenic differentiation. Collectively, these data suggest the involvement of GSK-3β in the glucocorticoid-mediated impairment of myogenic differentiation. Therefore, the inhibition of GSK-3β may be a strategy for preventing glucocorticoid-induced muscle degeneration.

  9. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors

    Energy Technology Data Exchange (ETDEWEB)

    Manceur, Aziza P. [Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario (Canada); Donnelly Centre, University of Toronto, Toronto, Ontario (Canada); Tseng, Michael [Laboratory of Cellular and Molecular Pathophysiology, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, ON (Canada); Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Holowacz, Tamara [Donnelly Centre, University of Toronto, Toronto, Ontario (Canada); Witterick, Ian [Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Department of Otolaryngology, Head and Neck Surgery, University of Toronto, ON (Canada); Weksberg, Rosanna [Institute of Medical Science, University of Toronto, Toronto, ON (Canada); The Hospital for Sick Children, Research Institute, Program in Genetics and Genomic Biology, Toronto, Ontario Canada (Canada); McCurdy, Richard D. [The Hospital for Sick Children, Research Institute, Program in Genetics and Genomic Biology, Toronto, Ontario Canada (Canada); Warsh, Jerry J. [Laboratory of Cellular and Molecular Pathophysiology, Centre for Addiction and Mental Health (CAMH), University of Toronto, Toronto, Ontario (Canada); Department of Psychiatry, University of Toronto, Toronto, ON (Canada); Institute of Medical Science, University of Toronto, Toronto, ON (Canada); Audet, Julie, E-mail: julie.audet@utoronto.ca [Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario (Canada); Donnelly Centre, University of Toronto, Toronto, Ontario (Canada)

    2011-09-10

    The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B) inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders.

  10. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors

    International Nuclear Information System (INIS)

    The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B) inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders.

  11. Monthly Changes of Glycogen, Lipid and Free Amino Acid of Oyster

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhicui; XUE Changhu; GAO Xin; LI Zhaojie; WANG Qi

    2006-01-01

    Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed.The components analyzed included glycogen, fatty acid and free amino acid (FAA).The content of glycogen was high in January and March (2.89 and 2.82 g(100 g)- 1 on average, respectively) and low in October (2.07 g(100 g)- 1 on average).The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g) -1 on average).The main fatty acids of oyster were palmitic acid(16:0),oleic acid(18:1),eicosapentaenoic acid (EPA,20:5w-3) and docosahexaenoic acid(DHA,22:6w-3).The major FAAs of oyster were Taurine,Glutamicacid,Glycin,Alanine, Arginine and Proline.Taurine was the most abundant FAA with its content ranging from 603 mg(100 g)- 1 to 1139 mg(100 g) -1.The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

  12. Monthly changes of glycogen, lipid and free amino acid of oyster

    Science.gov (United States)

    Zhicui, Zhang; Changhu, Xue; Xin, Gao; Zhaojie, Li; Qi, Wang

    2006-07-01

    Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed. The components analyzed included glycogen, fatty acid and free amino acid (FAA). The content of glycogen was high in January and March (2.89 and 2.82 g(100g)-1 on average, respectively) and low in October (2.07 g(100g)-1 on avarage). The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g)-1 on average). The main fatty acids of oyster were palmitic acid (16:0), oleic acid (18:1), eicosapentaenoic acid (EPA, 20: 5ω-3) and docosahexaenoic acid (DHA, 22:6ω-3). The major FAAs of oyster were Taurine, Glutamicacid, Glycin, Alanine, Arginine and Proline. Taurine was the most abundant FAA with its content ranging from 603 mg (100g)-1 to 1139 mg(100g)-1. The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

  13. GlycoGAIT: A web database to browse glycogenes and lectins under gastric inflammatory diseases.

    Science.gov (United States)

    Oommen, Anup Mammen; Somaiya, Neeti; Vijayan, Jisha; Kumar, Satheesh; Venkatachalam, Suri; Joshi, Lokesh

    2016-10-01

    The perplexing nature of dynamic glycosylation modification plays imperative role in determining the regulatory role of key glycoconjugates involved in immune system. Systematic analysis of change in expression pattern of glycogenes and lectins can bring in a comprehensive understanding of genetic basis of the glycobiological changes occurring in pathological condition. Advancement in the field of glycobiology has capacitated the process of linking gene expression changes of glycogenes with its biological function. This instigated us to systematically analyze changes in expression patterns focusing on glycome genomics under diverse gastrointestinal immune dysfunction background. To necessitate this, as a pilot project, we carefully integrated several publically available databases to construct a glycosylation process associated gene set as well as public expression microarray data associated with gastrointestinal infections into an online database called Glycosylation and Gut Associated Immune Tolerance (GlycoGAIT). Currently the database comprises of 548 well characterized genes belonging to glycogenes and lectins along with gene expression data obtained from human biopsy samples under both H. pylori infection and inflammatory bowel disease (IBD) condition. The user-friendly interface enables the users to quickly compare and interpret changes in expression patterns of glycome genomics under different gut associated inflammatory conditions. The database is available online at: https://apps.connexios.com/glycogait/. PMID:27436239

  14. Oral conjugated linoleic acid supplementation enhanced glycogen resynthesis in exercised human skeletal muscle.

    Science.gov (United States)

    Tsao, Jung-Piao; Liao, Su-Fen; Korivi, Mallikarjuna; Hou, Chien-Wen; Kuo, Chia-Hua; Wang, Hsueh-Fang; Cheng, I-Shiung

    2015-01-01

    Present study examined the effects of conjugated linoleic acid (CLA) supplementation on glycogen resynthesis in exercised human skeletal muscle. Twelve male participants completed a cross-over trial with CLA (3.8 g/day for 8 week) or placebo supplements by separation of 8 weeks. CLA is a mixture of trans-10 cis-12 and cis-9 trans-11 isomers (50:50). On experiment day, all participants performed 60-min cycling exercise at 75% VO2 max, then consumed a carbohydrate meal immediately after exercise and recovered for 3 h. Biopsied muscle samples from vastus lateralis were obtained immediately (0 h) and 3 h following exercise. Simultaneously, blood and gaseous samples were collected for every 30 min during 3-h recovery. Results showed significantly increased muscle glycogen content with CLA after a single bout of exercise (P Gaseous exchange data showed no beneficial effect of CLA on fat oxidation, instead lower non-esterified fatty acid and glycerol levels were found at 0 h. Our findings conclude that CLA supplementation can enhance the glycogen resynthesis rate in exercised human skeletal muscle. PMID:25385360

  15. Iminosugars as potential inhibitors of glycogenolysis: structural insights into the molecular basis of glycogen phosphorylase inhibition.

    Science.gov (United States)

    Oikonomakos, Nikos G; Tiraidis, Costas; Leonidas, Demetres D; Zographos, Spyros E; Kristiansen, Marit; Jessen, Claus U; Nørskov-Lauritsen, Leif; Agius, Loranne

    2006-09-21

    Iminosugars DAB (5), isofagomine (9), and several N-substituted derivatives have been identified as potent inhibitors of liver glycogen phosphorylase a (IC(50) = 0.4-1.2 microM) and of basal and glucagon-stimulated glycogenolysis (IC(50) = 1-3 microM). The X-ray structures of 5, 9, and its N-3-phenylpropyl analogue 8 in complex with rabbit muscle glycogen phosphorylase (GPb) shows that iminosugars bind tightly at the catalytic site in the presence of the substrate phosphate and induce conformational changes that characterize the R-state conformation of the enzyme. Charged nitrogen N1 is within hydrogen-bonding distance with the carbonyl oxygen of His377 (5) and in ionic contact with the substrate phosphate oxygen (8 and 9). Our findings suggest that the inhibitors function as oxocarbenium ion transition-state analogues. The conformational change to the R state provides an explanation for previous findings that 5, unlike inhibitors that favor the T state, promotes phosphorylation of GPb in hepatocytes with sequential inactivation of glycogen synthase. PMID:16970395

  16. Effect of Alpha-Particle Irradiation on Brain Glycogen in the Rat

    Science.gov (United States)

    Wolfe, L. S.; Klatzo, Igor; Miquel, Jaime; Tobias, Cornelius; Haymaker, Webb

    1962-01-01

    The studies of Klatzo, Miquel, Tobias and Haymaker (1961) have shown that one of the earliest and most sensitive indications of the effects of alpha-particle irradiation on rat bran is the appearance of glycogen granules mainly in the neuroglia of the exposed area of the brain. Periodic acid-Schiff (PAS) positive, alpha-amylase soluble granules were demonstrated within 12 hr after irradiation, preceding by approximately 36 hr the first microscopically detectable vascular permeability disturbances, as shown by the fluorescein labeled serum protein technique. These studies suggested that the injurious effects of alpha-particle energy were on cellular elements primarily, according to the physical properties and distribution of the radiation in the tissue, and that the vascular permeability disturbances played a secondary role in pathogenesis. The purpose of this study was to correlate the histochemical observations on glycogen with a quantitative assessment of the glycogen in the irradiated brain tissue. It is felt that such a study may contribute to the understanding of radiation injury at the molecular level. A practical aspect of this problem is that the information on biological radiation effects due to accelerated particles from the cyclotron source, is employed in this study, is applicable to radiation from cosmic particles both in free space and entrapped in the Van Allen belts.

  17. Control of neuronal ion channel function by glycogen synthase kinase-3: new prospective for an old kinase

    Directory of Open Access Journals (Sweden)

    Norelle Christine Wildburger

    2012-07-01

    Full Text Available Glycogen synthase kinase 3 (GSK-3 is an evolutionarily conserved multifaceted ubiquitous enzyme. In the central nervous system (CNS, GSK-3 acts through an intricate network of intracellular signaling pathways culminating in a highly divergent cascade of phosphorylations that control neuronal function during development and adulthood. Accumulated evidence indicates that altered levels of GSK-3 correlate with maladaptive plasticity of neuronal circuitries in psychiatric disorders, addictive behaviors, and neurodegenerative diseases, and pharmacological interventions known to limit GSK-3 can counteract some of these deficits. Thus, targeting the GSK-3 cascade for therapeutic interventions against this broad spectrum of brain diseases has raised a tremendous interest. Yet, the multitude of GSK-3 downstream effectors poses a substantial challenge in the development of selective and potent medications that could efficiently block or modulate the activity of this enzyme. Although the full range of GSK-3 molecular targets are far from resolved, exciting new evidence indicates that ion channels regulating excitability, neurotransmitter release, and synaptic transmission, which ultimately contribute to the mechanisms underling brain plasticity and higher level cognitive and emotional processing, are new promising targets of this enzyme. Here, we will revise this new emerging role of GSK-3 in controlling the activity of voltage-gated Na+, K+, Ca2+ channels and ligand-gated glutamate receptors with the goal of highlighting new relevant endpoints of the neuronal GSK-3 cascade that could provide a platform for a better understanding of the mechanisms underlying the dysfunction of this kinase in the CNS and serve as a guidance for medication development against the broad range of GSK-3-linked human diseases.

  18. Development of a transformation system for Chlamydia trachomatis: restoration of glycogen biosynthesis by acquisition of a plasmid shuttle vector.

    Directory of Open Access Journals (Sweden)

    Yibing Wang

    2011-09-01

    Full Text Available Chlamydia trachomatis remains one of the few major human pathogens for which there is no transformation system. C. trachomatis has a unique obligate intracellular developmental cycle. The extracellular infectious elementary body (EB is an infectious, electron-dense structure that, following host cell infection, differentiates into a non-infectious replicative form known as a reticulate body (RB. Host cells infected by C. trachomatis that are treated with penicillin are not lysed because this antibiotic prevents the maturation of RBs into EBs. Instead the RBs fail to divide although DNA replication continues. We have exploited these observations to develop a transformation protocol based on expression of β-lactamase that utilizes rescue from the penicillin-induced phenotype. We constructed a vector which carries both the chlamydial endogenous plasmid and an E.coli plasmid origin of replication so that it can shuttle between these two bacterial recipients. The vector, when introduced into C. trachomatis L2 under selection conditions, cures the endogenous chlamydial plasmid. We have shown that foreign promoters operate in vivo in C. trachomatis and that active β-lactamase and chloramphenicol acetyl transferase are expressed. To demonstrate the technology we have isolated chlamydial transformants that express the green fluorescent protein (GFP. As proof of principle, we have shown that manipulation of chlamydial biochemistry is possible by transformation of a plasmid-free C. trachomatis recipient strain. The acquisition of the plasmid restores the ability of the plasmid-free C. trachomatis to synthesise and accumulate glycogen within inclusions. These findings pave the way for a comprehensive genetic study on chlamydial gene function that has hitherto not been possible. Application of this technology avoids the use of therapeutic antibiotics and therefore the procedures do not require high level containment and will allow the analysis of genome

  19. Role of the direct and indirect pathways for glycogen synthesis in rat liver in the postprandial state

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.T.; Veech, R.L.

    1988-03-01

    The pathway for hepatic glycogen synthesis in the postprandial state was studied in meal-fed rats chronically cannulated in the portal vein. Plasma glucose concentration in the portal vein was found to be 4.50 +/- 1.01 mM (mean +/- SE; n = 3) before a meal and 11.54 +/- 0.70 mM (mean +/- SE; n = 4) after a meal in rats meal-fed a diet consisting of 100% commercial rat chow for 7 d. The hepatic-portal difference of plasma glucose concentration showed that liver released glucose in the fasted state and either extracted or released glucose after feeding depending on plasma glucose concentration in the portal vein. The concentration of portal vein glucose at which liver changes from glucose releasing to glucose uptake was 8 mM, the Km of glucokinase. The rate of glycogen synthesis in liver during meal-feeding was found to be approximately 1 mumol glucosyl U/g wet wt/min in rats meal-fed a 50% glucose supplemented chow diet. The relative importance of the direct vs. indirect pathway for the replenishment of hepatic glycogen was determined by the incorporation of (3-/sup 3/H,U-/sup 14/C)glucose into liver glycogen. Labeled glucose was injected into the portal vein at the end of meal-feeding. The ratio of /sup 3/H//sup 14/C in the glucosyl units of glycogen was found to be 83-92% of the ratio in liver free glucose six minutes after the injection, indicating that the majority of exogenous glucose incorporated into glycogen did not go through glycolysis. The percent contribution of the direct versus indirect pathway was quantitated from the difference in the relative specific activity (RSA) of (/sup 3/H) and (/sup 14/C)-glycogen in rats infused with (3-/sup 3/H,U-/sup 14/C)glucose. No significant difference was found between the RSA of (/sup 3/H)glycogen and (/sup 14/C)glycogen, indicating further that the pathway for glycogen synthesis in liver from exogenous glucose is from the direct pathway.

  20. Role of the direct and indirect pathways for glycogen synthesis in rat liver in the postprandial state

    International Nuclear Information System (INIS)

    The pathway for hepatic glycogen synthesis in the postprandial state was studied in meal-fed rats chronically cannulated in the portal vein. Plasma glucose concentration in the portal vein was found to be 4.50 +/- 1.01 mM (mean +/- SE; n = 3) before a meal and 11.54 +/- 0.70 mM (mean +/- SE; n = 4) after a meal in rats meal-fed a diet consisting of 100% commercial rat chow for 7 d. The hepatic-portal difference of plasma glucose concentration showed that liver released glucose in the fasted state and either extracted or released glucose after feeding depending on plasma glucose concentration in the portal vein. The concentration of portal vein glucose at which liver changes from glucose releasing to glucose uptake was 8 mM, the Km of glucokinase. The rate of glycogen synthesis in liver during meal-feeding was found to be approximately 1 mumol glucosyl U/g wet wt/min in rats meal-fed a 50% glucose supplemented chow diet. The relative importance of the direct vs. indirect pathway for the replenishment of hepatic glycogen was determined by the incorporation of [3-3H,U-14C]glucose into liver glycogen. Labeled glucose was injected into the portal vein at the end of meal-feeding. The ratio of 3H/14C in the glucosyl units of glycogen was found to be 83-92% of the ratio in liver free glucose six minutes after the injection, indicating that the majority of exogenous glucose incorporated into glycogen did not go through glycolysis. The percent contribution of the direct versus indirect pathway was quantitated from the difference in the relative specific activity (RSA) of [3H] and [14C]-glycogen in rats infused with [3-3H,U-14C]glucose. No significant difference was found between the RSA of [3H]glycogen and [14C]glycogen, indicating further that the pathway for glycogen synthesis in liver from exogenous glucose is from the direct pathway

  1. Plastids and Carotenoid Accumulation.

    Science.gov (United States)

    Li, Li; Yuan, Hui; Zeng, Yunliu; Xu, Qiang

    2016-01-01

    Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants. PMID:27485226

  2. Chimpanzee accumulative stone throwing.

    Science.gov (United States)

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  3. Effect of oat bran on time to exhaustion, glycogen content and serum cytokine profile following exhaustive exercise.

    Science.gov (United States)

    Donatto, Felipe F; Prestes, Jonato; Frollini, Anelena B; Palanch, Adrianne C; Verlengia, Rozangela; Cavaglieri, Claudia Regina

    2010-01-01

    The aim of this study was to evaluate the effect of oat bran supplementation on time to exhaustion, glycogen stores and cytokines in rats submitted to training. The animals were divided into 3 groups: sedentary control group (C), an exercise group that received a control chow (EX) and an exercise group that received a chow supplemented with oat bran (EX-O). Exercised groups were submitted to an eight weeks swimming training protocol. In the last training session, the animals performed exercise to exhaustion, (e.g. incapable to continue the exercise). After the euthanasia of the animals, blood, muscle and hepatic tissue were collected. Plasma cytokines and corticosterone were evaluated. Glycogen concentrations was measured in the soleus and gastrocnemius muscles, and liver. Glycogen synthetase-α gene expression was evaluated in the soleus muscle. Statistical analysis was performed using a factorial ANOVA. Time to exhaustion of the EX-O group was 20% higher (515 ± 3 minutes) when compared with EX group (425 ± 3 minutes) (p = 0.034). For hepatic glycogen, the EX-O group had a 67% higher concentrations when compared with EX (p = 0.022). In the soleus muscle, EX-O group presented a 59.4% higher glycogen concentrations when compared with EX group (p = 0.021). TNF-α was decreased, IL-6, IL-10 and corticosterone increased after exercise, and EX-O presented lower levels of IL-6, IL-10 and corticosterone levels in comparison with EX group. It was concluded that the chow rich in oat bran increase muscle and hepatic glycogen concentrations. The higher glycogen storage may improve endurance performance during training and competitions, and a lower post-exercise inflammatory response can accelerate recovery. PMID:20955601

  4. Effect of oat bran on time to exhaustion, glycogen content and serum cytokine profile following exhaustive exercise

    Directory of Open Access Journals (Sweden)

    Frollini Anelena B

    2010-10-01

    Full Text Available Abstract The aim of this study was to evaluate the effect of oat bran supplementation on time to exhaustion, glycogen stores and cytokines in rats submitted to training. The animals were divided into 3 groups: sedentary control group (C, an exercise group that received a control chow (EX and an exercise group that received a chow supplemented with oat bran (EX-O. Exercised groups were submitted to an eight weeks swimming training protocol. In the last training session, the animals performed exercise to exhaustion, (e.g. incapable to continue the exercise. After the euthanasia of the animals, blood, muscle and hepatic tissue were collected. Plasma cytokines and corticosterone were evaluated. Glycogen concentrations was measured in the soleus and gastrocnemius muscles, and liver. Glycogen synthetase-α gene expression was evaluated in the soleus muscle. Statistical analysis was performed using a factorial ANOVA. Time to exhaustion of the EX-O group was 20% higher (515 ± 3 minutes when compared with EX group (425 ± 3 minutes (p = 0.034. For hepatic glycogen, the EX-O group had a 67% higher concentrations when compared with EX (p = 0.022. In the soleus muscle, EX-O group presented a 59.4% higher glycogen concentrations when compared with EX group (p = 0.021. TNF-α was decreased, IL-6, IL-10 and corticosterone increased after exercise, and EX-O presented lower levels of IL-6, IL-10 and corticosterone levels in comparison with EX group. It was concluded that the chow rich in oat bran increase muscle and hepatic glycogen concentrations. The higher glycogen storage may improve endurance performance during training and competitions, and a lower post-exercise inflammatory response can accelerate recovery.

  5. Influence of high-intensity exercise training and anabolic androgenic steroid treatment on rat tissue glycogen content.

    Science.gov (United States)

    Cunha, Tatiana Sousa; Tanno, Ana Paula; Costa Sampaio Moura, Maria José; Marcondes, Fernanda Klein

    2005-07-15

    To increase tissue glycogen content many athletes use anabolic androgenic steroids (AAS). However, the literature concerning the effects of androgens on glycogen metabolism is conflicting. This study aimed to determine the influence of training and AAS on body weight (bw), triglycerides, glucose, tissue glycogen and transaminases levels. Male Wistar rats, randomized into four groups (sedentary vehicle (SV), sedentary AAS (SA), trained vehicle (TV) and trained AAS (TA)), were treated with nadrolone (5 mg/Kg, 2x/week, i.m.) or vehicle. Trained rats performed jumps into water (4 sets, 10 repetitions, 30 sec rest) carrying a 50-70% body wt-load strapped to the chest (5 days/week,6 weeks). Two days after the last session, the animals were killed (bifatorial ANOVA+Tukey test; P SV:0.13+/-0.01=TV:0.13+/-0.01=SA:0.14+/-0.01 mg/100 mg). In the soleus AAS increased glycogen (SA:0.53+/-0.03 vs. SV:0.43+/-0.01 and TA:0.58+/-0.02 vs. TV:0.48+/-0.01 mg/100 mg). Exercise training and AAS had no effect on blood glucose and transaminases levels. Training and AAS effects on glycogen supercompensation are tissue-dependent and the effects of association between them were only observed in the cardiac muscle. These data emphasize the necessity of more studies to confirm greater effects of AAS than those promoted by physical exercise. PMID:15904936

  6. Antiproton Accumulator (AA)

    CERN Multimedia

    Photographic Service

    1980-01-01

    The AA in its final stage of construction, before it disappeared from view under concrete shielding. Antiprotons were first injected, stochastically cooled and accumulated in July 1980. From 1981 on, the AA provided antiprotons for collisions with protons, first in the ISR, then in the SPS Collider. From 1983 on, it also sent antiprotons, via the PS, to the Low-Energy Antiproton Ring (LEAR). The AA was dismantled in 1997 and shipped to Japan.

  7. Accumulation of satellites

    International Nuclear Information System (INIS)

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (108 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind

  8. Information Accumulation in Development

    OpenAIRE

    Acemoglu, Daron; Zilibotti, Fabrizio

    1998-01-01

    We propose a model in which economic relations and institutions in advanced and less developed countires differ as these societies have access to different amounts of information. The lack of information in less developped economies makes it hard to evaluate the performance of managers, and leads to high "agency costs". Differencies in the amount of information have a variety of sources. As well as factors related to the informational infrastructure, we emphasize that societies accumulate inf...

  9. Chimpanzee accumulative stone throwing

    OpenAIRE

    Hjalmar S Kühl; Kalan, Ammie K.; Mimi Arandjelovic; Floris Aubert; Lucy D’Auvergne; Annemarie Goedmakers; Sorrel Jones; Laura Kehoe; Sebastien Regnaut; Alexander Tickle; Els Ton; Joost van Schijndel; Abwe, Ekwoge E; Samuel Angedakin; Anthony Agbor

    2016-01-01

    The authors would like to thank the Max Planck Society and Krekeler Foundation for generous funding of the Pan African Programme. The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behav...

  10. Inhibition of Glycogen Synthase Kinase-3β Improves Tolerance to Ischemia in Hypertrophied Hearts

    Science.gov (United States)

    Barillas, Rodrigo; Friehs, Ingeborg; Cao-Danh, Hung; Martinez, Joseph F.; del Nido, Pedro J.

    2012-01-01

    Background Hypertrophied myocardium is more susceptible to ischemia/reperfusion injury, in part owing to impaired insulin-mediated glucose uptake. Glycogen synthase kinase-3β (GSK-3β) is a key regulatory enzyme in glucose metabolism that, when activated, phosphorylates/inactivates target enzymes of the insulin signaling pathway. Glycogen synthase kinase-3β is regulated upstream by Akt-1. We sought to determine whether GSK-3β is activated in ischemic hypertrophied myocardium owing to impaired Akt-1 function, and whether inhibition with lithium (Li) or indirubin-3′-monoxime,5-iodo- (IMI), a specific inhibitor, improves post-ischemic myocardial recovery by improving glucose metabolism. Methods Pressure-overload hypertrophy was achieved by aortic banding in neonatal rabbits. At 6 weeks, isolated hypertrophied hearts underwent 30 minutes of normothermic ischemia and reperfusion with or without GSK-3β inhibitor (0.1 mM Li; 1 µM IMI) as cardioplegic additives. Cardiac function was measured before and after ischemia. Expression, activity of Akt-1 and GSK-3β, and lactate were determined at end-ischemia. Results Contractile function after ischemia was better preserved in hypertrophied hearts treated with GSK-3β inhibitors. Activity of Akt-1 was significantly impaired in hypertrophied myocardium at end-ischemia. Glycogen synthase kinase-3β enzymatic activity at end-ischemia was increased in hypertrophied hearts and was blocked by Li or IMI concomitant with significantly increased lactate production, indicating increased glycolysis. Conclusions Regulatory inhibition of GSK-3β by Akt-1 in hypertrophied hearts is impaired, leading to activation during ischemia. Inhibition of GSK-3β by Li or IMI improves tolerance to ischemia/reperfusion injury in hypertrophied myocardium. The likely protective mechanism is an increase in insulin-mediated glucose uptake, resulting in greater substrate availability for glycolysis during ischemia and early reperfusion. PMID:17588398

  11. Mitochondrial accumulation of APP and Abeta

    DEFF Research Database (Denmark)

    Pavlov, Pavel F; Petersen, Anna Camilla Hansson; Glaser, Elzbieta;

    2009-01-01

    Accumulating evidence suggest that alterations in energy metabolism are among the earliest events that occur in the Alzheimer disease (AD) affected brain. Energy consumption is drastically decreased in the AD-affected regions of cerebral cortex and hippocampus pointing towards compromised...... mitochondrial function of neurons within specific brain regions. This is accompanied by an elevated production of reactive oxygen species contributing to increased rates of neuronal loss in the AD-affected brain regions. In this review, we will discuss the role of mitochondrial function and dysfunction in AD...

  12. Histological Changes on Liver Glycogen Storage in Mice (Mus musculus) Caused by Unbalanced Diets

    OpenAIRE

    Esma Ulusoy; Banu Eren

    2008-01-01

    Weight-losing diets have appealed to people who want to lose weight in the short-term. They usually apply high-protein (HP) diets (like Atkin’s, Stillman’s, Scarsdale) which they practice for 2 weeks or so. Unfortunately, these people who have rapid weight loss return to their old habits and quickly regain the weight lost. We have shown in previous work that actually these weight losses have been associated with body fluids, protein and glycogen storage. In our study, we examined the effect o...

  13. Glycogen Synthase Kinase 3 Phosphorylates RBL2/p130 during Quiescence

    OpenAIRE

    Litovchick, Larisa; Chestukhin, Anton; DeCaprio, James A.

    2004-01-01

    Phosphorylation of the retinoblastoma-related or pocket proteins RB1/pRb, RBL1/p107, and RBL2/p130 regulates cell cycle progression and exit. While all pocket proteins are phosphorylated by cyclin-dependent kinases (CDKs) during the G1/S-phase transition, p130 is also specifically phosphorylated in G0-arrested cells. We have previously identified several phosphorylated residues that match the consensus site for glycogen synthase kinase 3 (GSK3) in the G0 form of p130. Using small-molecule inh...

  14. The Medical Nutritional Therapy for Glycogen Storage Diseases:Case Report and Literature Review

    Institute of Scientific and Technical Information of China (English)

    Chun-wei LI; Kang YU; Rong-rong LI; Ming LI; Min-jie ZHANG

    2014-01-01

    Glycogen storage diseases (GSDs) are a group of inherited metabolic diseases caused by inherited defects in one of enzymes in glycogenolysis or/and gluconeogenesis. The morbidity of GSDs ranges from 0.04% to 0.05%, according to European data. Since limited data are available, more studies are needed in diagnosis and treatment of GSDs. To date, medical nutritional therapy (MNT) has become an effective measure in improving the clinical outcome of GSDs patients. We reported 4 cases of GSDs with different manifestations, including hypoglycemia, hepatomegaly, splenomegaly and growth retardation. We also provided individualized nutritional interventions and literature review was conducted as well.

  15. Hepatic Glucose Production Increases in Response to Metformin Treatment in the Glycogen-depleted State

    DEFF Research Database (Denmark)

    Christensen, Mette Marie Hougaard; Højlund, Kurt; Hother-Nielsen, Ole; Stage, Tore Bjerregaard; Damkier, Per; Beck-Nielsen, Henning; Brøsen, Kim

    with two reduced-function alleles) were fasted for 42 h twice. In one of the periods, before the fasting, the volunteers were titrated to steady-state with 1 g metformin twice daily for seven days. Parameters of whole-body glucose metabolism were assessed using [3-3^H] glucose, indirect calorimetry and...... of glucagon (p=0.03) and cortisol (p=0.002). There was no effect of reduced-function OCT1 alleles on any of these measures. In the glycogen-depleted fasting state, metformin stimulates glycolytic glucose utilization and lactate production. This may trigger a rise in glucose counterregulatory hormones...

  16. Degradation of ATP and glycogen in cod ( Gadus morhua ) muscle during freezing

    DEFF Research Database (Denmark)

    Cappeln, Gertrud; Jessen, Flemming

    2001-01-01

    Changes in ATP, IMP, lactate and glycogen contents in the muscle of cod were followed during freezing at temperatures of -20C and -45C. ATP degradation was accompanied by a corresponding increase in IMP content. Simultaneous measurement of temperature showed that at both freezing rates, the...... greatest decrease in ATP content was observed when the temperature reached -0.8C. Glycolysis occurred during freezing of cod as indicated by an increase in lactate content. The changes found in all measured metabolites were more pronounced when freezing was performed at a slow rate compared to a fast rate...

  17. Uranium accumulation by Pseudomonas sp. EPS-5028

    International Nuclear Information System (INIS)

    Pseudomonas sp. EPS-5028 was examined for the ability to accumulate uranium from solutions. The uptake of uranium by this microorganism is very rapid and is affected by pH but not by temperature, metabolic inhibitors, culture time and the presence of various cations and anions. The amount of uranium absorbed by the cells increased as the uranium concentration of the solution increased up to 55 mg uranium/g cell dry weight. Electron microscopy indicated that uranium accumulated intracellularly as needle-like fibrils. Uranium could be removed chemically from the cells, which could then be reused a a biosorbent. (orig.)

  18. Unchanged gene expression of glycogen synthase in muscle from patients with NIDDM following sulphonylurea-induced improvement of glycaemic control

    DEFF Research Database (Denmark)

    Vestergaard, H; Lund, S; Bjørbaek, C; Pedersen, O

    1995-01-01

    treatment. Ten obese patients with NIDDM were studied before and after 8 weeks of treatment with a weight-maintaining diet in combination with the sulphonylurea gliclazide. Gliclazide treatment was associated with significant reductions in HbA1C (p=0.001) and fasting plasma glucose (p=0.005) as well as...... metabolism (p=0.02) was demonstrated in teh gliclazide-treated patients when compared to pre-treatment values. In biopsies obtained from vastus lateralis muscle during insulin infusion, the half-maximal activation of glycogen synthase was achieved at a significantly lower concentration of the allosteric...... activator glucose 6-phosphate (p=0.01). However, despite significant increases in both insulin-stimulated non-oxidative glucose metabolism and muscle glycogen synthase activation in gliclazide-treated patients no changes were found in levels of glycogen synthase mRNA or immunoreactive protein in muscle. In...

  19. Incorporation of 14C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication

    International Nuclear Information System (INIS)

    Incorporation of 14C glucose into glycogen and glucose-6-phosphate dehydrogenase activity in rat brain following carbon monoxide intoxication was studied. In brains of rats tested on the 20, 30 and 60th minute of exposure to CO and immediately after removal from the chamber the enzyme activity showed no essential deviation from the control level. In the group of rats tested 1 hour after taking them out from the chamber increase of the enzyme activity was noticed, amounting to about 33% of the control value. The brains tested 24 hours after exposure showed the largest increase of the enzyme activity by about 94%. In the next time periods, 48 and 72 hours after intoxication, the enzyme activity was decreasing. The glycogen content in brains of control animals increased 3 hours after CO intoxication by about 69%. The increase of glycogen synthesis was expressed by increase of the total radioactivity, which amounted to 160% of the control value. (Z.M.)

  20. Methods for detection and visualization of intracellular polymers stored by polyphosphate-accumulating microorganisms.

    Science.gov (United States)

    Serafim, Luísa S; Lemos, Paulo C; Levantesi, Caterina; Tandoi, Valter; Santos, Helena; Reis, Maria A M

    2002-09-01

    Polyphosphate-accumulating microorganisms (PAOs) are important in enhanced biological phosphorus (P) removal. Considerable effort has been devoted to understanding the biochemical nature of enhanced biological phosphorus removal (EBPR) and it has been shown that intracellular polymer storage plays an important role in PAO's metabolism. The storage capacity of PAOs gives them a competitive advantage over other microorganisms present that are not able to accumulate internal reserves. Intracellular polymers stored by PAOs include polyphosphate (poly-P), polyhydroxyalkanoates (PHAs) and glycogen. Staining procedures for qualitative visualization of polymers by optical microscopy and combinations of these procedures with molecular tools for in situ identification are described here. The strengths and weaknesses of widely used polymer quantification methods that require destruction of samples, are also discussed. Finally, the potential of in vivo nuclear magnetic resonance (NMR) spectroscopy for on-line measurement of intracellular reserves is reported. PMID:12069885

  1. The interaction between AMPKβ2 and the PP1-targeting subunit R6 is dynamically regulated by intracellular glycogen content.

    Science.gov (United States)

    Oligschlaeger, Yvonne; Miglianico, Marie; Dahlmans, Vivian; Rubio-Villena, Carla; Chanda, Dipanjan; Garcia-Gimeno, Maria Adelaida; Coumans, Will A; Liu, Yilin; Voncken, J Willem; Luiken, Joost J F P; Glatz, Jan F C; Sanz, Pascual; Neumann, Dietbert

    2016-04-01

    AMP-activated protein kinase (AMPK) is a metabolic stress-sensing kinase. We previously showed that glucose deprivation induces autophosphorylation of AMPKβ at Thr-148, which prevents the binding of AMPK to glycogen. Furthermore, in MIN6 cells, AMPKβ1 binds to R6 (PPP1R3D), a glycogen-targeting subunit of protein phosphatase type 1 (PP1), thereby regulating the glucose-induced inactivation of AMPK. In the present study, we further investigated the interaction of R6 with AMPKβ and the possible dependency on Thr-148 phosphorylation status. Yeast two-hybrid (Y2H) analyses and co-immunoprecipitation (IP) of the overexpressed proteins in human embryonic kidney (HEK) 293T) cells revealed that both AMPKβ1 and AMPK-β2 wild-type (WT) isoforms bind to R6. The AMPKβ-R6 interaction was stronger with the muscle-specific AMPKβ2-WT and required association with the substrate-binding motif of R6. When HEK293T cells or C2C12 myotubes were cultured in high-glucose medium, AMPKβ2-WT and R6 weakly interacted. In contrast, glycogen depletion significantly enhanced this protein interaction. Mutation of AMPKβ2 Thr-148 prevented the interaction with R6 irrespective of the intracellular glycogen content. Treatment with the AMPK activator oligomycin enhanced the AMPKβ2-R6 interaction in conjunction with increased Thr-148 phosphorylation in cells grown in low-glucose medium. These data are in accordance with R6 binding directly to AMPKβ2 when both proteins detach from the diminishing glycogen particle, which is simultaneous with increased AMPKβ2 Thr-148 autophosphorylation. Such a model points to a possible control of AMPK by PP1-R6 upon glycogen depletion in muscle. PMID:26831516

  2. Factors Affecting Methylmercury Accumulation in the Food Chain

    OpenAIRE

    Luengen, Allison

    2012-01-01

    The common scientific wisdom is that dissolved organic debris (from rotting dead plant material, for example) reduces the biological activity, and hence toxicity, of heavy metals such as mercury. Prior to the start of this project, however, a study showed that organic debris could also sometimes enhance build up of the toxic form of mercury in phytoplankton. This toxic form is called methylmercury (MeHg). It is produced in the aquatic environment by sulfur-reducing bacteria and biomagnifies t...

  3. Skeletal muscle glycogen content and particle size of distinct subcellular localizations in the recovery period after a high-level soccer match

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Krustrup, Peter; Nybo, Lars; Gunnarsson, Thomas P; Madsen, Klavs; Schrøder, Henrik Daa; Bangsbo, Jens; Ortenblad, Niels

    2012-01-01

    biopsy collected immediately after and 24, 48, 72 and 120 h after a competitive soccer match. Transmission electron microscopy was used to estimate the subcellular distribution of glycogen and individual particle size. During the first day of recovery, glycogen content increased by ~60% in all...

  4. Akt2 influences glycogen synthase activity in human skeletal muscle through regulation of NH2-terminal (sites 2+2a) phosphorylation

    DEFF Research Database (Denmark)

    Friedrichsen, Martin; Birk, Jesper Bratz; Richter, Erik; Ribel-Madsen, Rasmus; Pehmøller, Christian; Hansen, Bo Falck; Beck-Nielsen, Henning; Hirshman, Michael F; Goodyear, Laurie J; Vaag, Allan; Poulsen, Pernille; Wojtaszewski, Jørgen

    2013-01-01

    Type 2 diabetes is characterized by reduced muscle glycogen synthesis. The key enzyme in this process, glycogen synthase (GS), is activated via proximal insulin signaling, but the exact molecular events remain unknown. We previously demonstrated that phosphorylation of Threonine-308 on Akt (pAkt-...

  5. Identification of a Novel Mutation (867delA) in the Glucose-6-phosphatase Gene in Two Siblings with Glycogen Storage Disease Type Ia with Different Phenotypes

    NARCIS (Netherlands)

    Rake, Jan Peter; ten Berge, Annelies M.; Visser, Gepke; Verlind, Edwin; Niezen-Koning, Klary E.; Buys, Charles H. C. M.; Smit, G. Peter A.; Scheffer, Hans

    2000-01-01

    We identified a novel mutation (867delA) in the glucose-6-phosphatase gene of two siblings with glycogen storage disease type Ia. Although both siblings share the same mutations, their phenotype regarding adult height and hepatomegaly differs. In glycogen storage disease type Ia, substantial heterog

  6. Role of glycogen-lowering exercise in the change of fat oxidation in response to a high-fat diet.

    OpenAIRE

    Schrauwen, P; van Marken Lichtenbelt, W.D.; SARIS, W.H.M.; Westerterp, K.R.

    1997-01-01

    Department of Human Biology, Maastricht University, The Netherlands. One of the candidate factors for determining the increase of fat oxidation after a switch from a reduced-fat diet to a high-fat diet is the size of the glycogen storage. Therefore, we studied the effect of low glycogen stores on fat oxidation after a switch from a reduced-fat diet to a high-fat diet. Twelve healthy, nonobese males and females (age: 22 +/- 1 yr, body mass index: 21.0 +/- 0.7, maximal power output: 254 +/- 11 ...

  7. Oxidative capacity and glycogen content increase more in arm than leg muscle in sedentary women after intense training

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai Baastrup; Connolly, Luke; Weihe, Pál;

    2015-01-01

    in m. deltoideus of the HIS group compared to m. vastus lateralis of the SOC group for citrate synthase maximal activity (95±89 vs. 27±34%), citrate synthase protein expression (100±29 vs. 31±44%), 3-hydroxyacyl-CoA dehydrogenase maximal activity (35±43 vs. 3±25%), muscle glycogen content (63±76 vs....... 20±51%) and expression of mitochondrial complex II, III and IV. Additionally, HIS caused higher (P<0.05) increases than MOS in m. deltoideus citrate synthase maximal activity, citrate synthase protein expression, and muscle glycogen content. In conclusion, m. deltoideus has a higher adaptive...

  8. Muscle glycogen content and glucose uptake during exercise in humans: influence of prior exercise and dietary manipulation

    DEFF Research Database (Denmark)

    Steensberg, Adam; van Hall, Gerrit; Keller, Charlotte;

    2002-01-01

    on two occasions: one after 60 min of two-legged cycling (16 h prior to the experimental trial) followed by a high carbohydrate diet (HCHO) and the other after the same exercise followed by a low carbohydrate diet (LCHO) (Series 2). Muscle glycogen was decreased by 40 % when comparing the pre...... during exercise, 13 healthy men were studied during two series of experiments. Seven men completed 4 h of two-legged knee extensor exercise 16 h after reducing of muscle glycogen by completing 60 min of single-legged cycling (Series 1). A further six men completed 3 h of two-legged knee extensor exercise...

  9. Kinetic and crystallographic studies of glucopyranose spirohydantoin and glucopyranosylamine analogs inhibitors of glycogen phosphorylase.

    Science.gov (United States)

    Watson, Kimberly A; Chrysina, Evangelia D; Tsitsanou, Katerina E; Zographos, Spyros E; Archontis, Georgios; Fleet, George W J; Oikonomakos, Nikos G

    2005-12-01

    Glycogen phosphorylase (GP) is currently exploited as a target for inhibition of hepatic glycogenolysis under high glucose conditions. Spirohydantoin of glucopyranose and N-acetyl-beta-D-glucopyranosylamine have been identified as the most potent inhibitors of GP that bind at the catalytic site. Four spirohydantoin and three beta-D-glucopyranosylamine analogs have been designed, synthesized and tested for inhibition of GP in kinetic experiments. Depending on the functional group introduced, the K(i) values varied from 16.5 microM to 1200 microM. In order to rationalize the kinetic results, we determined the crystal structures of the analogs in complex with GP. All the inhibitors bound at the catalytic site of the enzyme, by making direct and water-mediated hydrogen bonds with the protein and by inducing minor movements of the side chains of Asp283 and Asn284, of the 280s loop that blocks access of the substrate glycogen to the catalytic site, and changes in the water structure in the vicinity of the site. The differences observed in the Ki values of the analogs can be interpreted in terms of variations in hydrogen bonding and van der Waals interactions, desolvation effects, ligand conformational entropy, and displacement of water molecules on ligand binding to the catalytic site. PMID:16222658

  10. The Crystal Structures of the Open and Catalytically Competent Closed Conformation of Escherichia coli Glycogen Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Fang; Jia, Xiaofei; Yep, Alejandra; Preiss, Jack; Geiger, James H.; (MSU)

    2009-07-06

    Escherichia coli glycogen synthase (EcGS, EC 2.4.1.21) is a retaining glycosyltransferase (GT) that transfers glucose from adenosine diphosphate glucose to a glucan chain acceptor with retention of configuration at the anomeric carbon. EcGS belongs to the GT-B structural superfamily. Here we report several EcGS x-ray structures that together shed considerable light on the structure and function of these enzymes. The structure of the wild-type enzyme bound to ADP and glucose revealed a 15.2 degrees overall domain-domain closure and provided for the first time the structure of the catalytically active, closed conformation of a glycogen synthase. The main chain carbonyl group of His-161, Arg-300, and Lys-305 are suggested by the structure to act as critical catalytic residues in the transglycosylation. Glu-377, previously thought to be catalytic is found on the alpha-face of the glucose and plays an electrostatic role in the active site and as a glucose ring locator. This is also consistent with the structure of the EcGS(E377A)-ADP-HEPPSO complex where the glucose moiety is either absent or disordered in the active site

  11. Effects of glucose on contractile function, [Ca2+]i, and glycogen in isolated mouse skeletal muscle.

    Science.gov (United States)

    Helander, Ingrid; Westerblad, Håkan; Katz, Abram

    2002-06-01

    Extensor digitorum longus muscles were stimulated to contract to fatigue and allowed to recover for 2 h in the absence or presence of 5.5 or 11 mM extracellular glucose. This was followed by a second fatigue run, which ended when the absolute force was the same as at the end of the first run. During the first fatigue run, the fluorescence ratio for indo 1 increased [reflecting an increase in myoplasmic free Ca2+ concentration ([Ca2+]i)] during the initial tetani, peaking at approximately 115% of the first tetanic value, followed by a continuous decrease to approximately 90% at fatigue. During the first fatigue run, myofibrillar Ca2+ sensitivity was significantly decreased. During the second run, the number of tetani was 57 +/- 6% of initial force in muscles that recovered in the absence of glucose and 110 +/- 6 and 119 +/- 2% of initial force in muscles that recovered in 5.5 and 11 mM glucose, respectively. Fluorescence ratios during the first, peak, and last tetani did not differ significantly between the first and second fatigue runs during any of the three conditions. Glycogen decreased by almost 50% during the first fatigue run and did not change further after recovery in the absence of glucose. After recovery in the presence of 5.5 and 11 mM glucose, glycogen increased 32 and 42% above the nonstimulated control value (P supercompensation following contraction can occur in the absence of insulin. PMID:11997245

  12. Mechanisms underlying impaired GLUT-4 translocation in glycogen-supercompensated muscles of exercised rats.

    Science.gov (United States)

    Kawanaka, K; Nolte, L A; Han, D H; Hansen, P A; Holloszy, J O

    2000-12-01

    Exercise training induces an increase in GLUT-4 in muscle. We previously found that feeding rats a high-carbohydrate diet after exercise, with muscle glycogen supercompensation, results in a decrease in insulin responsiveness so severe that it masks the effect of a training-induced twofold increase in GLUT-4 on insulin-stimulated muscle glucose transport. One purpose of this study was to determine whether insulin signaling is impaired. Maximally insulin-stimulated phosphatidylinositol (PI) 3-kinase activity was not significantly reduced, whereas protein kinase B (PKB) phosphorylation was approximately 50% lower (P supercompensated muscles of trained rats. The contraction-stimulated increase in AMP kinase activity, which has been implicated in the activation of glucose transport by contractions, was approximately 80% lower in the muscles of the fed compared with the fasted rats 18 h after exercise. These results show that both the insulin- and contraction-stimulated pathways for muscle glucose transport activation are impaired in glycogen-supercompensated muscles and provide insight regarding possible mechanisms. PMID:11093919

  13. EXPRESSION PATTERNS OF THE GLYCOGEN PHOSPHORYLASE GENE RELATED TO LARVAL DIAPAUSE IN Ostrinia furnacalis.

    Science.gov (United States)

    Guo, Jianqing; Zhang, Honggang; Edwards, Martin; Wang, Zhenying; Bai, Shuxiong; He, Kanglai

    2016-04-01

    Glycogen phosphorylase (GP) acts in the first step in release of glucose from glycogen, a form of energy storage for most organisms. To investigate the characteristics and expression pattern of GP gene (Ofgp) in the Asian corn borer, Ostrinia furnacalis (Guenée), larvae, we cloned and analyzed tissue transcription of Ofgp. The results indicate that the open reading frame (ORF) is 2,526 bp, encoding 841 amino acid. The calculated three-dimensional structure shows 33 α-helices and 24 β-sheets. Ofgp transcription levels varied significantly during the second to fifth instars under long-day (28°C, 16:8 L:D photoperiod, and 70-80% relative humidity (RH)) and short-day (24.5°C, 11:13 L:D photoperiod, and 70-80% RH) conditions, remained low during the prediapause phase, and then increased after about 36 d under short-day photoperiod. In the larvae reared under long-day condition, hemolymph ranked the highest in the transcript level of Ofgp. The highest transcription was recorded in the fat body and was lower in the other tissues in larvae reared under short-day condition. We found that Ofgp transcription increased linearly from October 2012 to January 2013. The transcript level was negatively correlated with environmental temperature. We infer the higher Ofgp transcription may enhance the cold hardiness of the diapause larvae. PMID:26748939

  14. Insulin activation of mouse diaphragm glycogen synthase (GS) involves generation of electrophoretically distinct subunit species

    International Nuclear Information System (INIS)

    Glycogen synthase, the rate limiting enzyme for glycogen synthesis, was analyzed in mouse diaphragm extracts both by immunoprecipitation and immunoblotting using specific antibodies raised to the rabbit muscle enzyme. Diaphragms, with the supporting ribs attached, were incubated either with or without [32P]P/sub i/ in the medium. In extracts from unincubated, rapidly frozen diaphragms, immunoblotting indicated the presence of 3 distinct species, separated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). In addition, phosphorylation of immunoprecipitated GS with the kinase F/sub A//GSK-3 converted the higher mobility forms into the low mobility species. In diaphragms incubated with [32P]P/sub i/, 32P was incorporated only into one of the GS species, that of lowest mobility, indicating differential labelling among the multiple subunit forms. Insulin action, which increased the -/+ glucose-6-P activity ratio from 0.2 to 0.4, converted the low mobility species to the two higher mobility forms. The authors propose that this effect of insulin can be explained by dephosphorylation in the proline/serine rich site 3 region of GS, which has potent influence on both mobility on SDS-PAGE and activity

  15. Ice slurry accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, K.G.; Kauffeld, M.

    1998-06-01

    More and more refrigeration systems are designed with secondary loops, thus reducing the refrigerant charge of the primary refrigeration plant. In order not to increase energy consumption by introducing a secondary refrigerant, alternatives to the well established single phase coolants (brines) and different concepts of the cooling plant have to be evaluated. Combining the use of ice-slurry - mixture of water, a freezing point depressing agent (antifreeze) and ice particles - as melting secondary refrigerant and the use of a cool storage makes it possible to build plants with secondary loops without increasing the energy consumption and investment. At the same time the operating costs can be kept at a lower level. The accumulation of ice-slurry is compared with other and more traditional storage systems. The method is evaluated and the potential in different applications is estimated. Aspects of practically use of ice-slurry has been examined in the laboratory at the Danish Technological Institute (DTI). This paper will include the final conclusions from this work concerning tank construction, agitator system, inlet, outlet and control. The work at DTI indicates that in some applications systems with ice-slurry and accumulation tanks have a great future. These applications are described by a varying load profile and a process temperature suiting the temperature of ice-slurry (-3 - -8/deg. C). (au)

  16. A sugar-inducible protein kinase, VvSK1, regulates hexose transport and sugar accumulation in grapevine cells

    OpenAIRE

    Lecourieux, Fatma; Lecourieux, David; Vignault, Céline; Delrot, Serge

    2010-01-01

    In grapevine (Vitis vinifera), as in many crops, soluble sugar content is a major component of yield and economical value. This paper identifies and characterizes a Glycogen Synthase Kinase3 protein kinase, cloned from a cDNA library of grape Cabernet Sauvignon berries harvested at the ripening stage. This gene, called VvSK1, was mainly expressed in flowers, berries, and roots. In the berries, it was strongly expressed at postvéraison, when the berries accumulate glucose, fructose, and abscis...

  17. Targeting Glycogen Synthase Kinase-3β for Therapeutic Benefit against Oxidative Stress in Alzheimer's Disease: Involvement of the Nrf2-ARE Pathway

    Directory of Open Access Journals (Sweden)

    Katja Kanninen

    2011-01-01

    Full Text Available Specific regions of the Alzheimer's disease (AD brain are burdened with extracellular protein deposits, the accumulation of which is concomitant with a complex cascade of overlapping events. Many of these pathological processes produce oxidative stress. Under normal conditions, oxidative stress leads to the activation of defensive gene expression that promotes cell survival. At the forefront of defence is the nuclear factor erythroid 2-related factor 2 (Nrf2, a transcription factor that regulates a broad spectrum of protective genes. Glycogen synthase kinase-3β (GSK-3β regulates Nrf2, thus making this kinase a potential target for therapeutic intervention aiming to boost the protective activation of Nrf2. This paper aims to review the neuroprotective role of Nrf2 in AD, with special emphasis on the role of GSK-3β in the regulation of the Nrf2 pathway. We also examine the potential of inducing GSK-3β by small-molecule activators, dithiocarbamates, which potentially exert their beneficial therapeutic effects via the activation of the Nrf2 pathway.

  18. Acumulación de cobre en una comunidad vegetal afectada por contaminación minera en el valle de Puchuncaví, Chile central Copper accumulation in a plant community affected by mining contamination in Puchuncaví valley, central Chile

    Directory of Open Access Journals (Sweden)

    ISABEL GONZÁLEZ

    2008-06-01

    Full Text Available Las especies hiperacumuladoras son capaces de acumular más de 1.000 mg kg-1 de metal en su biomasa aérea y son útiles en procesos de fitoextracción de metales en suelos contaminados por actividades mineras. Con el fin de identificar especies hiperacumuladoras representativas de las condiciones chilenas, se realizó una prospección dentro de la diversidad vegetal en el área afectada por las emisiones de la Fundición Ventanas (90-900 mg kg-1 de Cu total en suelos, así como en un área cercana a una pila de escorias de fundición (500-3.000 mg kg-1 de Cu total en suelos. Se determinaron las concentraciones de Cu en la biomasa aérea de las plantas. Los resultados indican que dentro de la diversidad del sitio existen al menos veintidós especies pseudometalofitas, es decir, ecotipos de especies comunes que son capaces de tolerar concentraciones de cobre en el suelo que para una planta normal serían tóxicas. Las especies fueron clasificadas según su concentración de cobre y mostraron en su mayoría media (200-600 mg kg-1 o baja (Hyperaccumulator plants species are capable of accumulating more than 1,000 mg Cu kg-1 in their shoots and are useful for metal phytoextraction in soils contaminated by mining activities. To identify the hyperaccumulator plants representative of the Chilean conditions, we carried out a survey of plant diversity in the área affected by the emissions of the Ventanas smelter (90-900 mg kg-1 of total Cu in soils and in a nearby área cióse to a smelter slug pile (500-3,000 mg kg-1 of total Cu in soils. Copper concentrations in the shoots of the studied plants were determined. Results indicate that there were at least twenty-two pseudometallophyte species, i.e., ecotypes of common species capable to tolérate concentrations of Cu in the soil that would be toxic for a normal plant. The species were classified by their copper accumulation and nearly all exhibited médium (200-600 mg kg-1 or low (< 200 mg kg-1

  19. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    Section 06 - 08*) of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A vacuum-tank, two bending magnets (BST06 and BST07 in blue) with a quadrupole (QDN07, in red) in between, another vacuum-tank, a wide quadrupole (QFW08) and a further tank . The tanks are covered with heating tape for bake-out. The tank left of BST06 contained the stack core pickup for stochastic cooling (see 7906193, 7906190, 8005051), the two other tanks served mainly as vacuum chambers in the region where the beam was large. Peter Zettwoch works on BST06. *) see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984)

  20. Solids Accumulation Scouting Studies

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  1. Corruption, Public Expenditure, and Human Capital Accumulation

    OpenAIRE

    Spyridon Boikos

    2013-01-01

    In this paper we investigate the effect of corruption on human capital accumulation through two channels. The first channel is through the effect of corruption on the public expenditure on education and the second channel is through the effect of corruption on the physical capital investment. Public expenditure on education affects positively human capital, while physical capital can obsolete human capital. Initially, we construct an endogenous two-sector growth model with human capital accum...

  2. Muscle ceramide content in man is higher in type I than type II fibers and not influenced by glycogen content

    DEFF Research Database (Denmark)

    Nordby, P; Prats, C; Kristensen, D;

    2010-01-01

    +/- 2 mL O2 min(-1) kg(-1)) participated in the study. On the first day, one leg was glycogen-depleted (DL) by exhaustive intermittent exercise followed by low carbohydrate diet. Next day, in the overnight fasted condition, muscle biopsies were excised from vastus lateralis before and after exhaustive...

  3. Inhibition of Glycogen Synthase Kinase-3ß Enhances Cognitive Recovery after Stroke: The Role of TAK1

    Science.gov (United States)

    Venna, Venugopal Reddy; Benashski, Sharon E.; Chauhan, Anjali; McCullough, Louise D.

    2015-01-01

    Memory deficits are common among stroke survivors. Identifying neuroprotective agents that can prevent memory impairment or improve memory recovery is a vital area of research. Glycogen synthase kinase-3ß (GSK-3ß) is involved in several essential intracellular signaling pathways. Unlike many other kinases, GSK-3ß is active only when…

  4. Changes in the activity levels of glutamine synthetase, glutaminase and glycogen synthetase in rats subjected to hypoxic stress

    Science.gov (United States)

    Vats, P.; Mukherjee, A. K.; Kumria, M. M. L.; Singh, S. N.; Patil, S. K. B.; Rangnathan, S.; Sridharan, K.

    Exposure to high altitude causes loss of body mass and alterations in metabolic processes, especially carbohydrate and protein metabolism. The present study was conducted to elucidate the role of glutamine synthetase, glutaminase and glycogen synthetase under conditions of chronic intermittent hypoxia. Four groups, each consisting of 12 male albino rats (Wistar strain), were exposed to a simulated altitude of 7620 m in a hypobaric chamber for 6 h per day for 1, 7, 14 and 21 days, respectively. Blood haemoglobin, blood glucose, protein levels in the liver, muscle and plasma, glycogen content, and glutaminase, glutamine synthetase and glycogen synthetase activities in liver and muscle were determined in all groups of exposed and in a group of unexposed animals. Food intake and changes in body mass were also monitored. There was a significant reduction in body mass (28-30%) in hypoxia-exposed groups as compared to controls, with a corresponding decrease in food intake. There was rise in blood haemoglobin and plasma protein in response to acclimatisation. Over a three-fold increase in liver glycogen content was observed following 1 day of hypoxic exposure (4.76+/-0.78 mg.g-1 wet tissue in normal unexposed rats; 15.82+/-2.30 mg.g-1 wet tissue in rats exposed to hypoxia for 1 day). This returned to normal in later stages of exposure. However, there was no change in glycogen synthetase activity except for a decrease in the 21-days hypoxia-exposed group. There was a slight increase in muscle glycogen content in the 1-day exposed group which declined significantly by 56.5, 50.6 and 42% following 7, 14, and 21 days of exposure, respectively. Muscle glycogen synthetase activity was also decreased following 21 days of exposure. There was an increase in glutaminase activity in the liver and muscle in the 7-, 14- and 21-day exposed groups. Glutamine synthetase activity was higher in the liver in 7- and 14-day exposed groups; this returned to normal following 21 days of exposure

  5. Glutamate Cysteine Ligase—Modulatory Subunit Knockout Mouse Shows Normal Insulin Sensitivity but Reduced Liver Glycogen Storage

    KAUST Repository

    Lavoie, Suzie

    2016-04-21

    Glutathione (GSH) deficits have been observed in several mental or degenerative illness, and so has the metabolic syndrome. The impact of a decreased glucose metabolism on the GSH system is well-known, but the effect of decreased GSH levels on the energy metabolism is unclear. The aim of the present study was to investigate the sensitivity to insulin in the mouse knockout (KO) for the modulatory subunit of the glutamate cysteine ligase (GCLM), the rate-limiting enzyme of GSH synthesis. Compared to wildtype (WT) mice, GCLM-KO mice presented with reduced basal plasma glucose and insulin levels. During an insulin tolerance test, GCLM-KO mice showed a normal fall in glycemia, indicating normal insulin secretion. However, during the recovery phase, plasma glucose levels remained lower for longer in KO mice despite normal plasma glucagon levels. This is consistent with a normal counterregulatory hormonal response but impaired mobilization of glucose from endogenous stores. Following a resident-intruder stress, during which stress hormones mobilize glucose from hepatic glycogen stores, KO mice showed a lower hyperglycemic level despite higher plasma cortisol levels when compared to WT mice. The lower hepatic glycogen levels observed in GCLM-KO mice could explain the impaired glycogen mobilization following induced hypoglycemia. Altogether, our results indicate that reduced liver glycogen availability, as observed in GCLM-KO mice, could be at the origin of their lower basal and challenged glycemia. Further studies will be necessary to understand how a GSH deficit, typically observed in GCLM-KO mice, leads to a deficit in liver glycogen storage.

  6. Glycogen and glucose metabolism are essential for early embryonic development of the red flour beetle Tribolium castaneum.

    Directory of Open Access Journals (Sweden)

    Amanda Fraga

    Full Text Available Control of energy metabolism is an essential process for life. In insects, egg formation (oogenesis and embryogenesis is dependent on stored molecules deposited by the mother or transcribed later by the zygote. In oviparous insects the egg becomes an isolated system after egg laying with all energy conversion taking place during embryogenesis. Previous studies in a few vector species showed a strong correlation of key morphogenetic events and changes in glucose metabolism. Here, we investigate glycogen and glucose metabolism in the red flour beetle Tribolium castaneum, an insect amenable to functional genomic studies. To examine the role of the key enzymes on glycogen and glucose regulation we cloned and analyzed the function of glycogen synthase kinase 3 (GSK-3 and hexokinase (HexA genes during T. castaneum embryogenesis. Expression analysis via in situ hybridization shows that both genes are expressed only in the embryonic tissue, suggesting that embryonic and extra-embryonic cells display different metabolic activities. dsRNA adult female injection (parental RNAi of both genes lead a reduction in egg laying and to embryonic lethality. Morphological analysis via DAPI stainings indicates that early development is impaired in Tc-GSK-3 and Tc-HexA1 RNAi embryos. Importantly, glycogen levels are upregulated after Tc-GSK-3 RNAi and glucose levels are upregulated after Tc-HexA1 RNAi, indicating that both genes control metabolism during embryogenesis and oogenesis, respectively. Altogether our results show that T. castaneum embryogenesis depends on the proper control of glucose and glycogen.

  7. Differential Expression of a Glycogen Phosphorylase Gene in Volvariella volvacea Mycelium Exposed to Low Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan; WANG Hong; LI Zhengpeng; LU Lianjing; CHEN Mingjie

    2014-01-01

    Relative expression of a glycogen phosphorylase gene (pyg)in mycelia of cold-sensitive (V23)and cold-tolerant (VH3)strains of Volvariella volvacea during exposure to low temperature (0 ℃)over time courses was quantified by real-time PCR using theα-tubulin gene as internal control.Pyg expression levels in strain V23 decreased after 4 h exposure and,although recovering after 6 h,still remained lower than untreated controls.Gene expression in strain VH3 decreased sharply after low temperature exposure for 2 h, reaching a minimum value after 8 h when the relative expression level was only 0.28 times that of untreated controls.Overall,although pyg expression decreased in both V23 and VH3 over prolonged exposure,the fall was less pronounced in strain V23 compared with VH3.

  8. Glycogen Synthase Kinase 3 Inhibitors in the Next Horizon for Alzheimer's Disease Treatment

    Directory of Open Access Journals (Sweden)

    Ana Martinez

    2011-01-01

    Full Text Available Glycogen synthase kinase 3 (GSK-3, a proline/serine protein kinase ubiquitously expressed and involved in many cellular signaling pathways, plays a key role in the pathogenesis of Alzheimer's disease (AD being probably the link between β-amyloid and tau pathology. A great effort has recently been done in the discovery and development of different new molecules, of synthetic and natural origin, able to inhibit this enzyme, and several kinetics mechanisms of binding have been described. The small molecule called tideglusib belonging to the thiadiazolidindione family is currently on phase IIb clinical trials for AD. The potential risks and benefits of this new kind of disease modifying drugs for the future therapy of AD are discussed in this paper.

  9. 3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary at-tempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

  10. 3-Glucosylated 5-amino-1,2,4-oxadiazoles: synthesis and evaluation as glycogen phosphorylase inhibitors

    Directory of Open Access Journals (Sweden)

    Marion Donnier-Maréchal

    2015-04-01

    Full Text Available Glycogen phosporylase (GP is a promising target for the control of glycaemia. The design of inhibitors binding at the catalytic site has been accomplished through various families of glucose-based derivatives such as oxadiazoles. Further elaboration of the oxadiazole aromatic aglycon moiety is now reported with 3-glucosyl-5-amino-1,2,4-oxadiazoles synthesized by condensation of a C-glucosyl amidoxime with N,N’-dialkylcarbodiimides or Vilsmeier salts. The 5-amino group introduced on the oxadiazole scaffold was expected to provide better inhibition of GP through potential additional interactions with the enzyme’s catalytic site; however, no inhibition was observed at 625 µM.

  11. The Antiproton Accumulator (AA)

    CERN Multimedia

    1980-01-01

    A section of the AA where the dispersion (and hence the horizontal beam size) is large. One can distinguish (left to right): A large vacuum-tank, a quadrupole (QDN09*), a bending magnet (BST08), another vacuum-tank, a wide quadrupole (QFW08) and (in the background) a further bending magnet (BST08). The tanks are covered with heating tape for bake-out. The tank left of QDN09 contained the kickers for stochastic pre-cooling (see 790621, 8002234, 8002637X), the other one served mainly as vacuum chamber in the region where the beam was large. Peter Zettwoch works on QFW08. * see: H. Koziol, Antiproton Accumulator Parameter List, PS/AA/Note 84-2 (1984) See under 7911303, 7911597X, 8004261 and 8202324. For photos of the AA in different phases of completion (between 1979 and 1982) see: 7911303, 7911597X, 8004261, 8004608X, 8005563X, 8005565X, 8006716X, 8006722X, 8010939X, 8010941X, 8202324, 8202658X, 8203628X .

  12. Batteries and accumulators in France

    International Nuclear Information System (INIS)

    The present report gives an overview of the batteries and accumulators market in France in 2011 based on the data reported through ADEME's Register of Batteries and accumulators. In 2001, the French Environmental Agency, known as ADEME, implemented a follow-up of the batteries and accumulators market, creating the Observatory of batteries and accumulators (B and A). In 2010, ADEME created the National Register of producers of Batteries and Accumulators in the context of the implementation of the order issued on November 18, 2009. This is one of the four enforcement orders for the decree 2009-1139 issued on September 22, 2009, concerning batteries and accumulators put on the market and the disposal of waste batteries and accumulators, and which transposes the EU-Directive 2006/66/CE into French law. This Register follows the former Observatory for batteries and accumulators. This Register aims to record the producers on French territory and to collect the B and A producers and recycling companies' annual reporting: the regulation indeed requires that all B and A producers and recycling companies report annually on the Register the quantities of batteries and accumulators they put on the market, collect and treat. Based on this data analysis, ADEME issues an annual report allowing both the follow-up of the batteries and accumulators market in France and communication regarding the achievement of the collection and recovery objectives set by EU regulation. This booklet presents the situation in France in 2011

  13. Two Cases of Pulmonary Hypertension Associated with Type III Glycogen Storage Disease.

    Science.gov (United States)

    Lee, Teresa M; Berman-Rosenzweig, Erika S; Slonim, Alfred E; Chung, Wendy K

    2011-01-01

    Glycogen storage diseases (GSDs) comprise a large, heterogeneous group of disorders characterized by abnormal glycogen deposition. Multiple cases in the literature have demonstrated an association between GSD type I and pulmonary arterial hypertension (PAH). We now also report on two patients with GSD type III and PAH, a novel association. The first patient was a 16-year-old girl of Nicaraguan descent with a history of hepatomegaly and growth retardation. Molecular testing identified a homozygous 17delAG mutation in AGL consistent with GSD type IIIb. At the age of 16, she was found to have PAH and was started on medical therapy. Two years later, she developed acute chest pain and died shortly thereafter. The second patient is a 13-year-old girl of Colombian descent homozygous for the c.3911dupA mutation consistent with GSD IIIa. An echocardiogram at age 2 showed left ventricular hypertrophy, which resolved following the institution of a high protein, moderate carbohydrate diet during the day and continuous gastric-tube feeding overnight. At the age of 12, she was found to have pulmonary hypertension. She was started on sildenafil, and her clinical status has shown marked improvement including normalization of her elevated transaminases. PAH may be a rare association in patients with GSD IIIa and IIIb and should be evaluated with screening echocardiograms for cardiac hypertrophy or if they present with symptoms of right-sided heart failure such as shortness of breath, chest pain, cyanosis, fatigue, dizziness, syncope, or edema. Early diagnosis of PAH is important as increasingly effective treatments are now available. PMID:23430832

  14. Regulation of the Dictyostelium glycogen phosphorylase 2 gene by cyclic AMP.

    Science.gov (United States)

    Sucic, J F; Selmin, O; Rutherford, C L

    1993-01-01

    A crucial developmental event in the cellular slime mold, Dictyostelium discoideum, is glycogen degradation. The enzyme that catalyzes this degradation, glycogen phosphorylase 2 (gp-2), is developmentally regulated and cAMP appears to be involved in this regulation. We have examined several aspects of the cAMP regulation of gp-2. We show that addition of exogenous cAMP to aggregation competent amoebae induced the appearance of gp-2 mRNA. The induction of gp-2 mRNA occurred within 1 and 1.5 h after the initial exposure to cAMP. Exposure to exogenous cAMP concentrations as low as 1.0 microM could induce gp-2 mRNA. We also examined the molecular mechanism through which cAMP induction of gp-2 occurs. Induction of gp-2 appears to result from a mechanism that does not require intracellular cAMP signaling, and may occur directly through a cAMP binding protein without the requirement of any intracellular signalling. We also examined the promoter region of the gp-2 gene for cis-acting elements that are involved in the cAMP regulation of gp-2. A series of deletions of the promoter were fused to a luciferase reporter gene and then analyzed for cAMP responsiveness. The results indicated that a region from -258 nucleotides to the transcriptional start site is sufficient for essentially full activity and appears to carry all necessary cis-acting sites for cAMP induction. Further deletion of 58 nucleotides from the 5' end, results in fivefold less activity in the presence of cAMP. Deletion of the next 104 nucleotides eliminates the cAMP response entirely. PMID:8222346

  15. Glucose and Glycogen Metabolism in Brugia malayi Is Associated with Wolbachia Symbiont Fitness.

    Science.gov (United States)

    Voronin, Denis; Bachu, Saheed; Shlossman, Michael; Unnasch, Thomas R; Ghedin, Elodie; Lustigman, Sara

    2016-01-01

    Wolbachia are endosymbiotic bacteria found in the majority of arthropods and filarial nematodes of medical and veterinary importance. They have evolved a wide range of symbiotic associations. In filarial nematodes that cause human lymphatic filariasis (Wuchereria bancrofti, Brugia malayi) or onchocerciasis (Onchocerca volvulus), Wolbachia are important for parasite development, reproduction and survival. The symbiotic bacteria rely in part on nutrients and energy sources provided by the host. Genomic analyses suggest that the strain of Wolbachia found in B. malayi (wBm) lacks the genes for two glycolytic enzymes--6-phosphofructokinase and pyruvate kinase--and is thus potentially unable to convert glucose into pyruvate, an important substrate for energy generation. The Wolbachia surface protein, wBm00432, is complexed to six B. malayi glycolytic enzymes, including aldolase. In this study we characterized two B. malayi aldolase isozymes and found that their expression is dependent on Wolbachia fitness and number. We confirmed by immuno-transmission electron microscopy that aldolase is associated with the Wolbachia surface. RNAi experiments suggested that aldolase-2 plays a significant role in both Wolbachia survival and embryogenesis in B. malayi. Treatment with doxycycline reduced Wolbachia fitness and increased the amount of both glucose and glycogen detected in the filarial parasite, indicating that glucose metabolism and glycogen storage in B. malayi are associated with Wolbachia fitness. This metabolic co-dependency between Wolbachia and its filarial nematode indicates that glycolysis could be a shared metabolic pathway between the bacteria and B. malayi, and thus a potential new target for anti-filarial therapy. PMID:27078260

  16. Homology between O-linked GlcNAc transferases and proteins of the glycogen phosphorylase superfamily.

    Science.gov (United States)

    Wrabl, J O; Grishin, N V

    2001-11-30

    The O-linked GlcNAc transferases (OGTs) are a recently characterized group of largely eukaryotic enzymes that add a single beta-N-acetylglucosamine moiety to specific serine or threonine hydroxyls. In humans, this process may be part of a sugar regulation mechanism or cellular signaling pathway that is involved in many important diseases, such as diabetes, cancer, and neurodegeneration. However, no structural information about the human OGT exists, except for the identification of tetratricopeptide repeats (TPR) at the N terminus. The locations of substrate binding sites are unknown and the structural basis for this enzyme's function is not clear. Here, remote homology is reported between the OGTs and a large group of diverse sugar processing enzymes, including proteins with known structure such as glycogen phosphorylase, UDP-GlcNAc 2-epimerase, and the glycosyl transferase MurG. This relationship, in conjunction with amino acid similarity spanning the entire length of the sequence, implies that the fold of the human OGT consists of two Rossmann-like domains C-terminal to the TPR region. A conserved motif in the second Rossmann domain points to the UDP-GlcNAc donor binding site. This conclusion is supported by a combination of statistically significant PSI-BLAST hits, consensus secondary structure predictions, and a fold recognition hit to MurG. Additionally, iterative PSI-BLAST database searches reveal that proteins homologous to the OGTs form a large and diverse superfamily that is termed GPGTF (glycogen phosphorylase/glycosyl transferase). Up to one-third of the 51 functional families in the CAZY database, a glycosyl transferase classification scheme based on catalytic residue and sequence homology considerations, can be unified through this common predicted fold. GPGTF homologs constitute a substantial fraction of known proteins: 0.4% of all non-redundant sequences and about 1% of proteins in the Escherichia coli genome are found to belong to the GPGTF

  17. Resistance imparted by vitamin C, vitamin e and vitamin B12 to the acute hepatic glycogen change in rats caused by noise.

    OpenAIRE

    Zhu,Bei-Wei; Piao, Mei-Lan; Zhang, Yu; Han, Song; An, Qing-Da; Murata, Yoshiyuki; Tada, Mikiro

    2006-01-01

    The effects of vitamin C, vitamin E and vitamin B12 on the noise-induced acute change in hepatic glycogen content in rats were investigated. The exposure of rats to 95 dB and 110 dB of noise acutely reduced their hepatic glycogens. Vitamin C (ascorbic acid) and vitamin E (alpha -tocopherol) attenuated the noise-inducedacute reduction in the hepatic glycogen contents. This result suggests that antioxidants could reduce the change via reactive oxygen species. Vitamin B12 (cobalamin) delayed the...

  18. Plastic Accumulation in the Mediterranean Sea

    KAUST Repository

    Cózar, Andrés

    2015-04-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  19. Plastic accumulation in the Mediterranean sea.

    Science.gov (United States)

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J Ignacio; Ubeda, Bárbara; Gálvez, José Á; Irigoien, Xabier; Duarte, Carlos M

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  20. Plastic accumulation in the Mediterranean sea.

    Directory of Open Access Journals (Sweden)

    Andrés Cózar

    Full Text Available Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2, as well as its frequency of occurrence (100% of the sites sampled, are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

  1. Plastic Accumulation in the Mediterranean Sea

    Science.gov (United States)

    Cózar, Andrés; Sanz-Martín, Marina; Martí, Elisa; González-Gordillo, J. Ignacio; Ubeda, Bárbara; Gálvez, José Á.; Irigoien, Xabier; Duarte, Carlos M.

    2015-01-01

    Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region. PMID:25831129

  2. Heat accumulation during pulsed laser materials processing.

    Science.gov (United States)

    Weber, Rudolf; Graf, Thomas; Berger, Peter; Onuseit, Volkher; Wiedenmann, Margit; Freitag, Christian; Feuer, Anne

    2014-05-01

    Laser materials processing with ultra-short pulses allows very precise and high quality results with a minimum extent of the thermally affected zone. However, with increasing average laser power and repetition rates the so-called heat accumulation effect becomes a considerable issue. The following discussion presents a comprehensive analytical treatment of multi-pulse processing and reveals the basic mechanisms of heat accumulation and its consequence for the resulting processing quality. The theoretical findings can explain the experimental results achieved when drilling microholes in CrNi-steel and for cutting of CFRP. As a consequence of the presented considerations, an estimate for the maximum applicable average power for ultra-shorts pulsed laser materials processing for a given pulse repetition rate is derived. PMID:24921828

  3. Factors Affecting Cu and Zn Accumulation in Earthworms in Vermicomposting Pig Dung and Sawdust Mixture%猪粪、木屑混合物蚯蚓堆制处理中蚓体Cu、Zn富集的影响因素

    Institute of Scientific and Technical Information of China (English)

    胡安; 梅凌斐; 张志; 单监利; 贾秀英; 朱维琴

    2012-01-01

    采用室内接种法,以赤子爱胜蚓(Eisenia fetida)构建生物反应器,研究猪粪、木屑混合物的蚯蚓堆制处理中,蚓体的生长状况及影响其Cu、Zn富集的主要因素.结果表明,接种密度为40 mg·g-1、湿度为75%同时有利于蚯蚓生长和基质消耗;温度为15℃对蚓体质量增加最有利,而温度为20℃最利于基质消耗;m(猪粪)∶m(木屑)为6∶4可同时利于蚓体质量增加和基质消耗.适宜的接种密度(48 mg·g-1)、湿度(70%)、温度(15℃)及较高比例的碳源辅料[m(猪粪)∶m(木屑)为6∶4]有利于蚓体对Cu的吸收和富集;低接种密度和高比例碳源辅料有利于蚓体对Zn的吸收,湿度和温度对蚓体Zn含量无显著影响,但蚓体Zn富集量分别在接种密度48 mg·g-1、m(猪粪) ∶m(木屑)为6∶4、湿度75%和温度15℃条件下达最大.%Vermireactors were set up containing pig dung and sawdust mixture inoculated with Eisenia fetida indoors to investigate factors affecting growth of and Cu or Zn accumulation in earthworms during the course of vermicomposting. Results demonstrate that earthworm growth and substrate consumption were both boosted when the inoculation density and humidity was set at 40 mg ? G-1 and 75% , respectively; the optimal temperature for earthworm growth was 15℃ , and for matrix consumption, 20℃ ; pig dung/sawdust ratio of 6:4 was conducive to both earthworm growth and substrate consumption. Cu uptake and accumulation by earthworms were facilitated in the context of appropriate inoculation density (48 mg ? G-1) , humidity (70% ) , temperature (15℃ ) and a higher proportion of carbon source materials in the mixture ( pig dung/sawdust ratio, 6:4). Lower inoculation density and a higher proportion of carbon source materials were advantageous to earthworm Zn uptake, whereas humidity and temperature exerted little effects on earthworm Zn concentration. Earthworm Zn accumulation was the highest in the treatment with 48

  4. Parallel evolution of the glycogen synthase 1 (muscle) gene Gys1 between Old World and New World fruit bats (Order: Chiroptera).

    Science.gov (United States)

    Fang, Lu; Shen, Bin; Irwin, David M; Zhang, Shuyi

    2014-10-01

    Glycogen synthase, which catalyzes the synthesis of glycogen, is especially important for Old World (Pteropodidae) and New World (Phyllostomidae) fruit bats that ingest high-carbohydrate diets. Glycogen synthase 1, encoded by the Gys1 gene, is the glycogen synthase isozyme that functions in muscles. To determine whether Gys1 has undergone adaptive evolution in bats with carbohydrate-rich diets, in comparison to insect-eating sister bat taxa, we sequenced the coding region of the Gys1 gene from 10 species of bats, including two Old World fruit bats (Pteropodidae) and a New World fruit bat (Phyllostomidae). Our results show no evidence for positive selection in the Gys1 coding sequence on the ancestral Old World and the New World Artibeus lituratus branches. Tests for convergent evolution indicated convergence of the sequences and one parallel amino acid substitution (T395A) was detected on these branches, which was likely driven by natural selection. PMID:25001420

  5. [Dependence of creatine kinase and glycogen synthetase activities of skeletal muscles on state of adenine nucleotide phosphorylation and cAMP metabolism].

    Science.gov (United States)

    Iakovlev, N N; Chagovets, N R; Maksimova, L V

    1980-01-01

    Changes in the contents of adenine nucleotides, creatine phosphate, inorganic phosphate, creatine, glucose-6-phosphate and glycogen and the activity of adenylate cyclase, creatine kinase, glycogen phosphorylase 31:51-AMP-phosphodiesterase and glycogen synthetase in muscles and of blood catecholamines were studied in adult rats before loading, immediately after the cessation of the muscular activity, and at rest. Adenine nucleotides are established to play a regulatory role in catabolic and anabolic processes nucleotides are established to play a regulatory role in catabolic and anabolic processes related to the muscular activity. It is established that compensation and supercompensation of the working losses of muscular creatine phosphate and glycogen are due to activation of anabolic processes under conditions of higher phosphorylation of the adenylic system. PMID:6247797

  6. Increased subsarcolemmal lipids in type 2 diabetes: effect of training on localization of lipids, mitochondria, and glycogen in sedentary human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Hey-Mogensen, Martin; Vind, Birgitte F;

    2010-01-01

    The purpose of the study was to investigate the effect of aerobic training and type 2 diabetes on intramyocellular localization of lipids, mitochondria, and glycogen. Obese type 2 diabetic patients (n = 12) and matched obese controls (n = 12) participated in aerobic cycling training for 10 wk...... and glycogen were the same in type 2 diabetic patients and control subjects, and showed in parallel with improved insulin sensitivity a similar increase in response to training, however, with a more pronounced increase in SS mitochondria and SS glycogen than in other localizations. In conclusion, this...... study, estimating intramyocellular localization of lipids, mitochondria, and glycogen, indicates that type 2 diabetic patients may be exposed to increased levels of SS lipids. Thus consideration of cell compartmentation may advance the understanding of the role of lipids in muscle function and type 2...

  7. Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Suetta, Charlotte; Hvid, Lars G;

    2010-01-01

    Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect of...... disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg...... casting. Biopsies were obtained from m. vastus lateralis before and after the immobilization period. Immobilization induced a decrement of intra glycogen content by 54% (P <0.001) in both age groups and in two ultrastructurally distinct fiber types, whereas the content of IMF and SS glycogen remained...

  8. A fermented soy permeate improves the skeletal muscle glucose level without restoring the glycogen content in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Malardé, Ludivine; Vincent, Sophie; Lefeuvre-Orfila, Luz; Efstathiou, Théo; Groussard, Carole; Gratas-Delamarche, Arlette

    2013-02-01

    Exercise is essential into the therapeutic management of diabetic patients, but their level of exercise tolerance is lowered due to alterations of glucose metabolism. As soy isoflavones have been shown to improve glucose metabolism, this study aimed to assess the effects of a dietary supplement containing soy isoflavones and alpha-galactooligosaccharides on muscular glucose, glycogen synthase (GSase), and glycogen content in a type 1 diabetic animal model. The dietary supplement tested was a patented compound, Fermented Soy Permeate (FSP), developed by the French Company Sojasun Technologies. Forty male Wistar rats were randomly assigned to control or diabetic groups (streptozotocin, 45 mg/kg). Each group was then divided into placebo or FSP-supplemented groups. Both groups received by oral gavage, respectively, water or diluted FSP (0.1 g/day), daily for a period of 3 weeks. At the end of the protocol, glycemia was noticed after a 24-h fasting period. Glucose, total GSase, and the glycogen content were determined in the skeletal muscle (gastrocnemius). Diabetic animals showed a higher blood glucose concentration, but a lower glucose and glycogen muscle content than controls. Three weeks of FSP consumption allowed to restore the muscle glucose concentration, but failed to reduce glycemia and to normalize the glycogen content in diabetic rats. Furthermore, the glycogen content was increased in FSP-supplemented controls compared to placebo controls. Our results demonstrated that diabetic rats exhibited a depleted muscle glycogen content (-25%). FSP-supplementation normalized the muscle glucose level without restoring the glycogen content in diabetic rats. However, it succeeded to increase it in the control group (+20%). PMID:23356441

  9. Insights into Glycogen Metabolism in Chemolithoautotrophic Bacteria from Distinctive Kinetic and Regulatory Properties of ADP-Glucose Pyrophosphorylase from Nitrosomonas europaea

    OpenAIRE

    Machtey, Matías; Kuhn, Misty L.; Flasch, Diane A; Aleanzi, Mabel; Ballicora, Miguel A; Iglesias, Alberto A.

    2012-01-01

    Nitrosomonas europaea is a chemolithoautotroph that obtains energy by oxidizing ammonia in the presence of oxygen and fixes CO2 via the Benson-Calvin cycle. Despite its environmental and evolutionary importance, very little is known about the regulation and metabolism of glycogen, a source of carbon and energy storage. Here, we cloned and heterologously expressed the genes coding for two major putative enzymes of the glycogen synthetic pathway in N. europaea, ADP-glucose pyrophosphorylase and...

  10. Sunflower plants nutrients accumulation and oil yield as affected by achenes vigour and sowing densityAcúmulo de nutrientes e rendimento de óleo em plantas de girassol influenciados pelo vigor dos aquênios e pela densidade de semeadura

    Directory of Open Access Journals (Sweden)

    Madelon Rodrigues Sá Braz

    2010-02-01

    Full Text Available The objective this work was to evaluate the nutrients accumulation and achenes oil yield in sunflower plants as affected by achenes vigour and sowing density. An experiment was installed in the field at Seropédica, State of Rio de Janeiro, in October 2006 with three lots of sunflower achenes, cultivar Embrapa 122 V2000, classified as low, medium and high vigour and two sowing density (45,000 e 75,000 seeds.ha-1. The collected were realized at 20, 60 and 100 days after planting (DAP to the determination the dry mater, nitrogen, phosphorus, potassium and calcium. In the collecting at 100 DAP too it was evaluated the achene yield (kg ha-1, the content oil and oil yield (kg ha-1. The results indicated that to the 60 days high accumulation of dry mater, N, P K and Ca in stem, leaves and total at density of 45,000 seeds ha-1. The sunflower achenes oil yield and achenes and nutrients harvest index not affected by the achenes vigour and sowing density to. There was a preferential translocation of N and P for the achenes.O objetivo do trabalho foi avaliar o acúmulo de nutrientes e o rendimento de óleo dos aquênios em plantas de girassol produzidas sob a influência do vigor dos aquênios e da densidade de semeadura. Para isto, foi instalado um experimento no campo experimental no município de Seropédica/RJ, em outubro de 2006, com três distintos lotes de aquênios de girassol cv Embrapa 122 V2000, classificados como de baixo, de médio e de alto vigor, sob duas densidades de semeadura (45.000 e 75.000 sementes ha-1. Aos 20, 60 e 100 dias após a semeadura (DAS, foram coletadas as plantas para avaliação da massa de matéria seca e do acúmulo de nitrogênio, de fósforo, de potássio e de cálcio, no caule, nas folhas e nos capítulos. Nas plantas coletadas aos 100 DAS, foi feita também a avaliação do rendimento de aquênios (kg ha-1, do teor de óleo e do rendimento de óleo (kg ha-1. Observou-se que aos 60 DAS, no período entre o

  11. Enhanced Glycogen Storage of a Subcellular Hot Spot in Human Skeletal Muscle during Early Recovery from Eccentric Contractions

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Farup, Jean; Rahbek, Stine Klejs;

    2015-01-01

    content during post-exercise recovery from eccentric contractions. Analysis was completed on five male subjects performing an exercise bout consisting of 15 x 10 maximal eccentric contractions. Carbohydrate-rich drinks were subsequently ingested throughout a 48 h recovery period and muscle biopsies...... for analysis included time points 3, 24 and 48 h post exercise from the exercising leg, whereas biopsies corresponding to prior to and at 48 h after the exercise bout were collected from the non-exercising, control leg. Quantitative imaging by transmission electron microscopy revealed an early (post 3 and 24 h...... in both type I and II fibers were lower in the exercise leg compared with the control leg, and this was associated with a smaller size of the glycogen particles. We conclude that in the carbohydrate-supplemented state, the effect of eccentric contractions on glycogen metabolism depends on the subcellular...

  12. 13C/31P NMR studies on the role of glucose transport/phosphorylation in human glycogen supercompensation.

    Science.gov (United States)

    Price, T B; Laurent, D; Petersen, K F

    2003-05-01

    This study measured muscle glycogen during a 7-day carbohydrate loading protocol. Twenty healthy subjects (12 male, 8 female) performed 1 hr treadmill/toe-raise exercise immediately before a 3-day low carbohydrate (LoCHO) diet (20 % carbohydrate, 60 % fat, 20 % protein). On day 3 they repeated the exercise and began a 4-day high carbohydrate (HiCHO) diet (90 % carbohydrate, 2 % fat, 8 % protein). The order of administration of the diet was reversed in a subpopulation (n = 3). Interleaved natural abundance 13C/ 31P NMR spectra were obtained before and immediately after exercise, and each day during the controlled diets in order to determine concentrations of glycogen (GLY), glucose-6-phosphate (G6P), and muscle pH. Following exercise, muscle GLY and pH were reduced (p supercompensation. PMID:12784164

  13. Clinical presentation and biochemical findings children with glycogen storage disease type 1A

    International Nuclear Information System (INIS)

    To determine the clinical pattern of presentation and biochemical characteristics of glycogen storage disease (GSD) type 1a in children at a tertiary referral centre. Study Design: Descriptive/ cross sectional study. Place and Duration of Study: Department of Pediatric, division of Gastroenterology and Hepatology of the Children's hospital, Lahore over a period of 11 years. Patients and Methods: Confirmed cases of glycogen storage disease (clinical plus biochemical findings consistent with GSD 1a and proven on liver biopsy) were enrolled in this study from neonatal age till 18 years. Data was retrieved from files and electronic record for these cases. Diagnosis was made on the basis of history, clinical findings including hepatomegaly, hypertriglyceridemia, hypercholesterolemia, hypoglycemia and hyperuricemia (if present). Diagnosis was confirmed on liver biopsy. Patients with other storage disorders and benign and malignant tumours were excluded from the study. Results: Total patients included in the study were 360 with male to female ratio of 1.25:1. Median age at the time of diagnosis was 25.6 months (age range from one month to 18 years). Most common presentation was abdominal distension (83%) followed by failure to thrive (69%) and recurrent wheezing and diarrhoea (44%) each. Seizures were present in only 1/3rd of children. Other presentations included vomiting, respiratory distress, altered sensorium, nephrocalcinosis, epistaxis and hypothyroidism. Few patients around 11% presented with acute hepatitis and later were diagnosed as GSD. Significant hepatomegaly was evident in almost all patients but nephromegaly was present in only 5.5% patients. All children had marked hypertriglyceridemia but cholesterol levels were raised in 1/3rd of children. A large majority of children had deranged ALT more than 2 times of normal and around 38% children had marked anemia. Significant hypoglycemia and metabolic acidosis was documented in around 1/3rd of children

  14. Glycogen phosphorylase inhibitors: a free energy perturbation analysis of glucopyranose spirohydantoin analogues.

    Science.gov (United States)

    Archontis, G; Watson, K A; Xie, Q; Andreou, G; Chrysina, E D; Zographos, S E; Oikonomakos, N G; Karplus, M

    2005-12-01

    GP catalyzes the phosphorylation of glycogen to Glc-1-P. Because of its fundamental role in the metabolism of glycogen, GP has been the target for a systematic structure-assisted design of inhibitory compounds, which could be of value in the therapeutic treatment of type 2 diabetes mellitus. The most potent catalytic-site inhibitor of GP identified to date is spirohydantoin of glucopyranose (hydan). In this work, we employ MD free energy simulations to calculate the relative binding affinities for GP of hydan and two spirohydantoin analogues, methyl-hydan and n-hydan, in which a hydrogen atom is replaced by a methyl- or amino group, respectively. The results are compared with the experimental relative affinities of these ligands, estimated by kinetic measurements of the ligand inhibition constants. The calculated binding affinity for methyl-hydan (relative to hydan) is 3.75 +/- 1.4 kcal/mol, in excellent agreement with the experimental value (3.6 +/- 0.2 kcal/mol). For n-hydan, the calculated value is 1.0 +/- 1.1 kcal/mol, somewhat smaller than the experimental result (2.3 +/- 0.1 kcal/mol). A free energy decomposition analysis shows that hydan makes optimum interactions with protein residues and specific water molecules in the catalytic site. In the other two ligands, structural perturbations of the active site by the additional methyl- or amino group reduce the corresponding binding affinities. The computed binding free energies are sensitive to the preference of a specific water molecule for two well-defined positions in the catalytic site. The behavior of this water is analyzed in detail, and the free energy profile for the translocation of the water between the two positions is evaluated. The results provide insights into the role of water molecules in modulating ligand binding affinities. A comparison of the interactions between a set of ligands and their surrounding groups in X-ray structures is often used in the interpretation of binding free energy

  15. [A cytophotometric study of the RNA and glycogen content of human hepatocytes at different stages in the development of traumatic disease].

    Science.gov (United States)

    Kudriavtseva, M V; Shteĭn, G I; Shashkov, B V; Kudriavtsev, B N

    1992-01-01

    Absorption and fluorescent cytophotometry techniques were applied to studies of RNA, glycogen and its fractions in hepatocytes of patients with hard mechanic trauma, both with and without endointoxication. For measuring RNA and glycogen contents, slides were stained by gallocyanin-chromalum or underwent fluorescent PAS-reaction, respectively. The repeated aspiration biopsy material was used for investigation of RNA and glycogen contents in dynamics. A quick increase in RNA content took place at the first stage (within the first 3 days) of traumatic illness of both the groups of patients. At the second stage of illness the hepatocyte RNA content in patients without endointoxication was seen to decrease to the initial level, whereas that in patients with endointoxication increased from the initial level by 36%. At different stages of illness the total glycogen content is changed insignificantly in the course of illness, but its labile fraction decreases to 70% of the total glycogen in patients with endointoxication. The increase of hepatocyte synthetic activity and the maintenance of the normal glycogen level may suggest a sufficient compensatory possibility of the liver, in spite of a high functional load under endointoxication. PMID:1284098

  16. Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

    International Nuclear Information System (INIS)

    Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca2+ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting 32P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated 32P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor

  17. Phosphorylation of inhibitor-2 and activation of MgATP-dependent protein phosphatase by rat skeletal muscle glycogen synthase kinase

    Energy Technology Data Exchange (ETDEWEB)

    Hegazy, M.G.; Reimann, E.M.; Thysseril, T.J.; Schlender, K.K.

    1986-05-01

    Rat skeletal muscle contains a glycogen synthase kinase (GSK-M) which is not stimulated by Ca/sup 2 +/ or cAMP. This kinase has an apparent Mr of 62,000 and uses ATP but not GTP as a phosphoryl donor. GSK-M phosphorylated glycogen synthase at sites 2 and 3. It phosphorylated ATP-citrate lyase and activated MgATP-dependent phosphatase in the presence of ATP but not GTP. As expected, the kinase also phosphorylated phosphatase inhibitor 2 (I-2). Phosphatase incorporation reached approximately 0.3 mol/mol of I-2. Phosphopeptide maps were obtained by digesting /sup 32/P-labeled I-2 with trypsin and separating the peptides by reversed phase HPLC. Two partially separated /sup 32/P-labeled peaks were obtained when I-2 was phosphorylated with either GSK-M or glycogen synthase kinase 3 (GSK-3) and these peptides were different from those obtained when I-2 was phosphorylated with the catalytic subunit of cAMP-dependent protein kinase (CSU) or casein kinase II (CK-II). When I-2 was phosphorylated with GSK-M or GSK-3 and cleaved by CNBr, a single radioactive peak was obtained. Phosphoamino acid analysis showed that I-2 was phosphorylated by GSK-M or GSK-3 predominately in Thr whereas CSU and CK-II phosphorylated I-2 exclusively in Ser. These results indicate that GSK-M is similar to GSK-3 and to ATP-citrate lyase kinase. However, it appears to differ in Mr from ATP-citrate lyase kinase and it differs from GSK-3 in that it phosphorylates glycogen synthase at site 2 and it does not use GTP as a phosphoryl donor.

  18. Hepatorenal correction in murine glycogen storage disease type I with a double-stranded adeno-associated virus vector.

    LENUS (Irish Health Repository)

    Luo, Xiaoyan

    2011-11-01

    Glycogen storage disease type Ia (GSD-Ia) is caused by the deficiency of glucose-6-phosphatase (G6Pase). Long-term complications of GSD-Ia include life-threatening hypoglycemia and proteinuria progressing to renal failure. A double-stranded (ds) adeno-associated virus serotype 2 (AAV2) vector encoding human G6Pase was pseudotyped with four serotypes, AAV2, AAV7, AAV8, and AAV9, and we evaluated efficacy in 12-day-old G6pase (-\\/-) mice. Hypoglycemia during fasting (plasma glucose <100 mg\\/dl) was prevented for >6 months by the dsAAV2\\/7, dsAAV2\\/8, and dsAAV2\\/9 vectors. Prolonged fasting for 8 hours revealed normalization of blood glucose following dsAAV2\\/9 vector administration at the higher dose. The glycogen content of kidney was reduced by >65% with both the dsAAV2\\/7 and dsAAV2\\/9 vectors, and renal glycogen content was stably reduced between 7 and 12 months of age for the dsAAV2\\/9 vector-treated mice. Every vector-treated group had significantly reduced glycogen content in the liver, in comparison with untreated G6pase (-\\/-) mice. G6Pase was expressed in many renal epithelial cells of with the dsAAV2\\/9 vector for up to 12 months. Albuminuria and renal fibrosis were reduced by the dsAAV2\\/9 vector. Hepatorenal correction in G6pase (-\\/-) mice demonstrates the potential of AAV vectors for the correction of inherited diseases of metabolism.

  19. The effect of 3-methylcholanthrene and butylated hydroxytoluene on glycogen levels of liver, muscle, testis, and tumor tissues of rats

    OpenAIRE

    POLAT, Fikriye; DERE, Egemen; GÜL, Eylem; YELKUVAN, İzzet; ÖZDEMİR, Öztürk; BİNGÖL, Günsel

    2013-01-01

    This study examined the effects of separate and combined applications of 3-methylcholanthrene, a polycyclic aromatic hydrocarbon and potent carcinogenic agent, and butylated hydroxytoluene, the antioxidant food additive, on the glycogen levels of liver, muscle, testis, and tumor tissues in rats. Adult male Wistar albino rats weighing 100-110 g at 8 weeks of age were used in this study. This study consisted of a control group (n = 9) and 3 different experiment groups in which rats were chronic...

  20. Garlic (Allium sativum) Extract Supplementation Alters the Glycogen Deposition in Liver and Protein Metabolism in Gonads of Female Albino Rats

    OpenAIRE

    Sashank Srivastava; P. H. Pathak

    2012-01-01

    Garlic is an ayurvedic herb that has been extensively used as medication and as the taste enhancer of the food. The present investigation was undertaken to provide data on the efficacy of garlic (Allium sativum Linn.) extract on glycogen deposition and protein metabolism in female albino rats that may further explore medicinal potential of garlic. The rats were divided into four groups A, B, C and D, keeping group A as a healthy control. The garlic extract was tried in three different doses, ...

  1. Effect of oat bran on time to exhaustion, glycogen content and serum cytokine profile following exhaustive exercise

    OpenAIRE

    Frollini Anelena B; Prestes Jonato; Donatto Felipe F; Palanch Adrianne C; Verlengia Rozangela; Cavaglieri Claudia

    2010-01-01

    Abstract The aim of this study was to evaluate the effect of oat bran supplementation on time to exhaustion, glycogen stores and cytokines in rats submitted to training. The animals were divided into 3 groups: sedentary control group (C), an exercise group that received a control chow (EX) and an exercise group that received a chow supplemented with oat bran (EX-O). Exercised groups were submitted to an eight weeks swimming training protocol. In the last training session, the animals performe...

  2. Deficiency in the Inhibitory Serine-Phosphorylation of Glycogen Synthase Kinase-3 Increases Sensitivity to Mood Disturbances

    OpenAIRE

    Polter, Abigail; Beurel, Eléonore; Yang, Sufen; Garner, Rakesha; Song, Ling; Miller, Courtney A; Sweatt, J. David; McMahon, Lori; Bartolucci, Alfred A.; Li, Xiaohua; Richard S Jope

    2010-01-01

    Bipolar disorder, characterized by extreme manic and depressive moods, is a prevalent debilitating disease of unknown etiology. Because mood stabilizers, antipsychotics, antidepressants, and mood-regulating neuromodulators increase the inhibitory serine-phosphorylation of glycogen synthase kinase-3 (GSK3), we hypothesized that deficient GSK3 serine-phosphorylation may increase vulnerability to mood-related behavioral disturbances. This was tested by measuring behavioral characteristics of GSK...

  3. Segmental extracellular and intracellular water distribution and muscle glycogen after 72-h carbohydrate loading using spectroscopic techniques.

    Science.gov (United States)

    Shiose, Keisuke; Yamada, Yosuke; Motonaga, Keiko; Sagayama, Hiroyuki; Higaki, Yasuki; Tanaka, Hiroaki; Takahashi, Hideyuki

    2016-07-01

    Body water content increases during carbohydrate loading because 2.7-4-g water binds each 1 g of glycogen. Bioelectrical impedance spectroscopy (BIS) allows separate assessment of extracellular and intracellular water (ECW and ICW, respectively) in the whole body and each body segment. However, BIS has not been shown to detect changes in body water induced by carbohydrate loading. Here, we aimed to investigate whether BIS had sufficient sensitivity to detect changes in body water content and to determine segmental water distribution after carbohydrate loading. Eight subjects consumed a high-carbohydrate diet containing 12 g carbohydrates·kg body mass(-1)·day(-1) for 72 h after glycogen depletion cycling exercise. Changes in muscle glycogen concentration were measured by (13)C-magnetic resonance spectroscopy, and total body water (TBW) was measured by the deuterium dilution technique (TBWD2O). ICW and ECW in the whole body (wrist-to-ankle) and in each body segment (arm, trunk, and leg) were assessed by BIS. Muscle glycogen concentration [72.7 ± 10.0 (SD) to 169.4 ± 55.9 mmol/kg wet wt, P < 0.001] and TBWD2O (39.3 ± 3.2 to 40.2 ± 3.0 kg, P < 0.05) increased significantly 72 h after exercise compared with baseline, respectively. Whole-body BIS showed significant increases in ICW (P < 0.05), but not in ECW. Segmental BIS showed significant increases in ICW in the legs (P < 0.05), but not in the arms or trunk. Our results suggest that increase in body water after carbohydrate loading can be detected by BIS and is caused by segment-specific increases in ICW. PMID:27231310

  4. Glycogen-graft-poly(2-alkyl-2-oxazolines) - the new versatile biopolymer-based thermoresponsive macromolecular toolbox

    Czech Academy of Sciences Publication Activity Database

    Pospíšilová, Aneta; Filippov, Sergey K.; Bogomolova, Anna; Turner, S.; Sedláček, Ondřej; Matushkin, Nikolai; Černochová, Zulfiya; Štěpánek, Petr; Hrubý, Martin

    2014-01-01

    Roč. 4, č. 106 (2014), s. 61580-61588. ISSN 2046-2069 R&D Projects: GA ČR GA13-08336S; GA MŠk(CZ) LH14079 Grant ostatní: AV ČR(CZ) M200501201; AV ČR(CZ) ASCR/CONICET 2012CZ006 Institutional support: RVO:61389013 Keywords : glycogen * poly(2-alkyl-2-oxazoline) * hybrid copolymer Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.840, year: 2014

  5. Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3

    OpenAIRE

    Marta ePardo; King, Margaret K.; EMMA ePEREZ-COSTAS; Miguel eMelendez-Ferro; Ana eMartinez; Eleonore eBeurel; Richard Scott Jope

    2015-01-01

    ABSTRACTBrain glycogen synthase kinase-3 (GSK3) is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC). To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive ta...

  6. Enhancement of uranium-accumulating ability of microorganisms by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, Takashi; Nakajima, Akira; Tsuruta, Takehiko [Miyazaki Medical Coll., Kiyotake (Japan)

    1998-01-01

    Some microorganisms having excellent ability to accumulate uranium were isolated, from soil and water systems in and around the Ningyo-toge Station of Power Reactor and Nuclear Fuel Development Corporation. The enhancement of uranium-accumulating ability of microorganisms by electron-beam irradiation was examined, and the ability of JW-046 was increased 3-5% by the irradiation. The irradiation affect the growth of some of microorganisms tested. (author)

  7. Quantitative Phosphoproteomic Study Reveals that Protein Kinase A Regulates Neural Stem Cell Differentiation Through Phosphorylation of Catenin Beta-1 and Glycogen Synthase Kinase 3β.

    Science.gov (United States)

    Wang, Shuxin; Li, Zheyi; Shen, Hongyan; Zhang, Zhong; Yin, Yuxin; Wang, Qingsong; Zhao, Xuyang; Ji, Jianguo

    2016-08-01

    Protein phosphorylation is central to the understanding of multiple cellular signaling pathways responsible for regulating the self-renewal and differentiation of neural stem cells (NSCs). Here we performed a large-scale phosphoproteomic analysis of rat fetal NSCs using strong cation exchange chromatography prefractionation and citric acid-assisted two-step enrichment with TiO2 strategy followed by nanoLC-MS/MS analysis. Totally we identified 32,546 phosphosites on 5,091 phosphoproteins, among which 23,945 were class I phosphosites, and quantified 16,000 sites during NSC differentiation. More than 65% of class I phosphosites were novel when compared with PhosphoSitePlus database. Quantification results showed that the early and late stage of NSC differentiation differ greatly. We mapped 69 changed phosphosites on 20 proteins involved in Wnt signaling pathway, including S552 on catenin beta-1 (Ctnnb1) and S9 on glycogen synthase kinase 3β (Gsk3β). Western blotting and real-time PCR results proved that Wnt signaling pathway plays critical roles in NSC fate determination. Furthermore, inhibition and activation of PKA dramatically affected the phosphorylation state of Ctnnb1 and Gsk3β, which regulates the differentiation of NSCs. Our data provides a valuable resource for studying the self-renewal and differentiation of NSCs. Stem Cells 2016;34:2090-2101. PMID:27097102

  8. Garlic (Allium sativum Extract Supplementation Alters the Glycogen Deposition in Liver and Protein Metabolism in Gonads of Female Albino Rats

    Directory of Open Access Journals (Sweden)

    Sashank Srivastava

    2012-04-01

    Full Text Available Garlic is an ayurvedic herb that has been extensively used as medication and as the taste enhancer of the food. The present investigation was undertaken to provide data on the efficacy of garlic (Allium sativum Linn. extract on glycogen deposition and protein metabolism in female albino rats that may further explore medicinal potential of garlic. The rats were divided into four groups A, B, C and D, keeping group A as a healthy control. The garlic extract was tried in three different doses, 1ml, 2ml and 4ml/ kg body weight as low, medium and high dose respectively and given orally for the period of 7, 14, 21 and 28 days daily to the rats of group B, C and D as stated above. The significant (P<0.01 & P<0.05 increase in glycogen and protein level was observed when rats were fed with low and medium dose but when rats were fed with high dose of garlic extract there was significant (P<0.01 decrease in glycogen level and a not significant decrease in protein level was observed.

  9. Campylobacter jejuni CsrA complements an Escherichia coli csrA mutation for the regulation of biofilm formation, motility and cellular morphology but not glycogen accumulation

    OpenAIRE

    Fields Joshua A; Thompson Stuart A

    2012-01-01

    Abstract Background Although Campylobacter jejuni is consistently ranked as one of the leading causes of bacterial diarrhea worldwide, the mechanisms by which C. jejuni causes disease and how they are regulated have yet to be clearly defined. The global regulator, CsrA, has been well characterized in several bacterial genera and is known to regulate a number of independent pathways via a post transcriptional mechanism, but remains relatively uncharacterized in the genus Campylobacter. Previou...

  10. Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

    OpenAIRE

    Pronk, M; Abbas, B.; Kleerebezem, R.; M. C. M. van Loosdrecht

    2015-01-01

    The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand the relatively long aeration periods. Lowering the anaerobic solid retention time (SRT) from 17 to 8 days enabled selective removal of the methanogens a...

  11. Research Advancement of the Effects of the Co-ingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise%运动后联合补充糖与蛋白质对肌糖原合成效果的研究进展

    Institute of Scientific and Technical Information of China (English)

    李良; 苏浩

    2015-01-01

    Muscle glycogen is the major energy source in human body ,it can provide the energy for muscle contraction rapidly .A large amount of muscle glycogen will be depleted after long term and high intensity exercise ,and it will affect the exercise performance also .The rapid syn‐thesis of muscle glycogen is an important part for the post‐exercise recovery ,many studies have reported that the process of muscle glycogen synthesis can be accelerated by the supple‐mentation of carbohydrate after exercise .On the other hand ,some recent studies found that the muscle glycogen synthesis can be further promoted by the co‐ingestion of carbohydrate and protein after exercise .However ,some other studies were not observed positive results .Based on the summarization and analysis of the published scientific papers ,this paper found out that the ingestion rate of carbohydrate and protein was the major reason for the inconsistent find‐ings among different studies .If the ingestion rate of carbohydrate was slower than 1 .0 ~ 1 .2 g/kg/h ,the co‐ingestion of protein at a rate of 0 .2 ~ 0 .4 g/kg/h will promote the muscle glycogen synthesis rate significantly .The higher insulin level after the ingestion of protein will enhance the transportation of glucose ,and protein supplementation can also strengthen the ac‐tivity of glycogen synthetase ,the both reasons may resulted in the greater synthesis rate of muscle glycogen after protein ingestion .However ,the suitable forms and types of the supplied proteins ,and also the potential mechanisms behind the findings have not been investigated clearly so far .Further studies can focus on the abovementioned questions and provide evidences for making scientific nutrition supplementation programmes which can promote the muscle gly‐cogen synthesis rate after exercise .%肌糖原(Muscle Glycogen)是人体中主要的糖储备形式,可为肌肉收缩迅速提供能量。长时间、高强度的运动会大量消耗肌糖原

  12. Checking for reversibility of aggregation of UV-irradiated glycogen phosphorylase b under crowding conditions.

    Science.gov (United States)

    Eronina, Tatiana B; Mikhaylova, Valeriya V; Chebotareva, Natalia A; Makeeva, Valentina F; Kurganov, Boris I

    2016-05-01

    It is believed that the initial stages of protein aggregation are reversible and can be reversed by simple dilution, whereas prolonged exposure to factors responsible for denaturing proteins (for example, to elevated temperatures) results in the formation of irreversible aggregates. A new approach has been developed to discriminate the stage of the formation of reversible aggregates. Aggregation of UV-irradiated glycogen phosphorylase b (UV-Phb) was studied at 10, 25 and 37°C in the presence of crowders (polyethylene glycol and Ficoll-70) using dynamic light scattering and analytical ultracentrifugation (pH 6.8; 0.1M NaCl). The dilution of the protein solution in the course of aggregation at 10°C results in the breakdown of protein aggregates suggesting that the aggregation process is reversible. When aggregation of UV-Phb is studied at 37°C, reversibility is lacking. Chemical chaperones (arginine, proline) induce the breakdown of protein aggregates of UV-Phb formed at 10°C. In the experiments carried out at 37°C in the presence of crowder the addition of arginine results in disintegration of protein aggregates only at early stages of the aggregation process. It is assumed that general pathway of protein aggregation includes the formation of reversible, completely dissociable, partly dissociable and irreversible aggregates. PMID:26853826

  13. Progress in Enzyme Replacement Therapy in Glycogen Storage Disease Type II.

    Science.gov (United States)

    Angelini, Corrado; Semplicini, Claudio; Tonin, Paola; Filosto, Massimiliano; Pegoraro, Elena; Sorarù, Gianni; Fanin, Marina

    2009-05-01

    Glycogen storage disease type II (GSDII) is an autosomal recessive lysosomal disorder caused by mutations in the gene encoding alpha-glucosidase (GAA). The disease can be clinically classified into three types: a severe infantile form, a juvenile and an adultonset form. Cases with juvenile or adult onset GSDII mimic limb-girdle muscular dystrophy or polymyositis and are often characterized by respiratory involvement. GSDII patients are diagnosed by biochemical assay and by molecular characterization of the GAA gene. Ascertaining a natural history of patients with heterogeneous late-onset GSDII is useful for evaluating their progressive functional disability. A significant decline is observed over the years in skeletal and respiratory muscle function. Enzyme replacement therapy (ERT) has provided encouraging results in the infantile form. It is not yet known if ERT is effective in late-onset GSDII. We examined a series of 11 patients before and after ERT evaluating muscle strength by MRC, timed and graded functional tests, 6-minute walk test (6MWT), respiratory function by spirometric parameters and quality of life. We observed a partial improvement during a prolonged follow-up from 3 to 18 months. The use of different clinical parameters in the proposed protocol seems crucial to determine the efficacy of ERT, since not all late-onset patients respond similarly to ERT. PMID:21179524

  14. Inhibitors of Glycogen Synthase Kinase 3 with Exquisite Kinome-Wide Selectivity and Their Functional Effects.

    Science.gov (United States)

    Wagner, Florence F; Bishop, Joshua A; Gale, Jennifer P; Shi, Xi; Walk, Michelle; Ketterman, Joshua; Patnaik, Debasis; Barker, Doug; Walpita, Deepika; Campbell, Arthur J; Nguyen, Shannon; Lewis, Michael; Ross, Linda; Weïwer, Michel; An, W Frank; Germain, Andrew R; Nag, Partha P; Metkar, Shailesh; Kaya, Taner; Dandapani, Sivaraman; Olson, David E; Barbe, Anne-Laure; Lazzaro, Fanny; Sacher, Joshua R; Cheah, Jaime H; Fei, David; Perez, Jose; Munoz, Benito; Palmer, Michelle; Stegmaier, Kimberly; Schreiber, Stuart L; Scolnick, Edward; Zhang, Yan-Ling; Haggarty, Stephen J; Holson, Edward B; Pan, Jen Q

    2016-07-15

    The mood stabilizer lithium, the first-line treatment for bipolar disorder, is hypothesized to exert its effects through direct inhibition of glycogen synthase kinase 3 (GSK3) and indirectly by increasing GSK3's inhibitory serine phosphorylation. GSK3 comprises two highly similar paralogs, GSK3α and GSK3β, which are key regulatory kinases in the canonical Wnt pathway. GSK3 stands as a nodal target within this pathway and is an attractive therapeutic target for multiple indications. Despite being an active field of research for the past 20 years, many GSK3 inhibitors demonstrate either poor to moderate selectivity versus the broader human kinome or physicochemical properties unsuitable for use in in vitro systems or in vivo models. A nonconventional analysis of data from a GSK3β inhibitor high-throughput screening campaign, which excluded known GSK3 inhibitor chemotypes, led to the discovery of a novel pyrazolo-tetrahydroquinolinone scaffold with unparalleled kinome-wide selectivity for the GSK3 kinases. Taking advantage of an uncommon tridentate interaction with the hinge region of GSK3, we developed highly selective and potent GSK3 inhibitors, BRD1652 and BRD0209, which demonstrated in vivo efficacy in a dopaminergic signaling paradigm modeling mood-related disorders. These new chemical probes open the way for exclusive analyses of the function of GSK3 kinases in multiple signaling pathways involved in many prevalent disorders. PMID:27128528

  15. Esophageal Stricture Secondary to Candidiasis in a Child with Glycogen Storage Disease 1b.

    Science.gov (United States)

    Lee, Kyung Jae; Choi, Shin Jie; Kim, Woo Sun; Park, Sung-Sup; Moon, Jin Soo; Ko, Jae Sung

    2016-03-01

    Esophageal candidiasis is commonly seen in immunocompromised patients; however, candida esophagitis induced stricture is a very rare complication. We report the first case of esophageal stricture secondary to candidiasis in a glycogen storage disease (GSD) 1b child. The patient was diagnosed with GSD type 1b by liver biopsy. No mutation was found in the G6PC gene, but SLC37A4 gene sequencing revealed a compound heterozygous mutation (p.R28H and p.W107X, which was a novel mutation). The patient's absolute neutrophil count was continuously under 1,000/µL when he was over 6 years of age. He was admitted frequently for recurrent fever and infection, and frequently received intravenous antibiotics, antifungal agents. He complained of persistent dysphagia beginning at age 7 years. Esophageal stricture and multiple whitish patches were observed by endoscopy and endoscopic biopsy revealed numerous fungal hyphae consistent with candida esophagitis. He received esophageal balloon dilatation four times, and his symptoms improved. PMID:27066451

  16. Glucose-based spiro-isoxazolines: a new family of potent glycogen phosphorylase inhibitors.

    Science.gov (United States)

    Benltifa, Mahmoud; Hayes, Joseph M; Vidal, Sébastien; Gueyrard, David; Goekjian, Peter G; Praly, Jean-Pierre; Kizilis, Gregory; Tiraidis, Costas; Alexacou, Kyra-Melinda; Chrysina, Evangelia D; Zographos, Spyros E; Leonidas, Demetres D; Archontis, Georgios; Oikonomakos, Nikos G

    2009-10-15

    A series of glucopyranosylidene-spiro-isoxazolines was prepared through regio- and stereoselective [3+2]-cycloaddition between the methylene acetylated exo-glucal and aromatic nitrile oxides. The deprotected cycloadducts were evaluated as inhibitors of muscle glycogen phosphorylase b. The carbohydrate-based family of five inhibitors displays K(i) values ranging from 0.63 to 92.5 microM. The X-ray structures of the enzyme-ligand complexes show that the inhibitors bind preferentially at the catalytic site of the enzyme retaining the less active T-state conformation. Docking calculations with GLIDE in extra-precision (XP) mode yielded excellent agreement with experiment, as judged by comparison of the predicted binding modes of the five ligands with the crystallographic conformations and the good correlation between the docking scores and the experimental free binding energies. Use of docking constraints on the well-defined positions of the glucopyranose moiety in the catalytic site and redocking of GLIDE-XP poses using electrostatic potential fit-determined ligand partial charges in quantum polarized ligand docking (QPLD) produced the best results in this regard. PMID:19781947

  17. Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis

    Directory of Open Access Journals (Sweden)

    Hoseok Choi

    2016-04-01

    Full Text Available Assaying the glycogen synthase kinase-3 (GSK3 activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts.

  18. Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis.

    Science.gov (United States)

    Choi, Hoseok; Choi, Bomi; Seo, Ju Tae; Lee, Kyung Jin; Gye, Myung Chan; Kim, Young-Pil

    2016-01-01

    Assaying the glycogen synthase kinase-3 (GSK3) activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed) peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts. PMID:27092510

  19. Vascular endothelial growth factor in skeletal muscle following glycogen-depleting exercise in humans

    DEFF Research Database (Denmark)

    Jensen, Line

    2015-01-01

    Vascular endothelial growth factor (VEGF) is traditionally considered important for skeletal muscle angiogenesis. VEGF is released from vascular endothelium as well as the muscle cells in response to exercise. The mechanism and the physiological role of VEGF secreted from the muscle cells remain...... unclear. However, as VEGF is also considered very important for the regulation of vascular permeability, it is possible that metabolic stress may trigger muscle VEGF release. PURPOSE: To study the role of metabolic stress induced by glycogen-depleting exercise on muscle VEGF expression. METHODS: Fifteen...... males (age 27.0±0.8; VO2max 66.0±1.2 ml•kg-1•min-1) carried out 4h of cycling exercise supplied with H2O only followed by 4h of recovery with either carbohydrate (CHO) (n=8) or H2O (n=7) supplementation. Hereafter both groups received CHO. Muscle biopsies were collected pre and post as well as 4 and 24...

  20. Glycogen Synthase Kinase 3β Inhibition as a Therapeutic Approach in the Treatment of Endometrial Cancer

    Directory of Open Access Journals (Sweden)

    Liang Ma

    2013-08-01

    Full Text Available Alternative strategies beyond current chemotherapy and radiation therapy regimens are needed in the treatment of advanced stage and recurrent endometrial cancers. There is considerable promise for biologic agents targeting the extracellular signal-regulated kinase (ERK pathway for treatment of these cancers. Many downstream substrates of the ERK signaling pathway, such as glycogen synthase kinase 3β (GSK3β, and their roles in endometrial carcinogenesis have not yet been investigated. In this study, we tested the importance of GSK3β inhibition in endometrial cancer cell lines and in vivo models. Inhibition of GSK3β by either lithium chloride (LiCl or specific GSK3β inhibitor VIII showed cytostatic and cytotoxic effects on multiple endometrial cancer cell lines, with little effect on the immortalized normal endometrial cell line. Flow cytometry and immunofluorescence revealed a G2/M cell cycle arrest in both type I (AN3CA, KLE, and RL952 and type II (ARK1 endometrial cancer cell lines. In addition, LiCl pre-treatment sensitized AN3CA cells to the chemotherapy agent paclitaxel. Administration of LiCl to AN3CA tumor-bearing mice resulted in partial or complete regression of some tumors. Thus, GSK3β activity is associated with endometrial cancer tumorigenesis and its pharmacologic inhibition reduces cell proliferation and tumor growth.

  1. Glycogen synthase kinase 3α regulates urine concentrating mechanism in mice

    DEFF Research Database (Denmark)

    Nørregaard, Rikke; Tao, Shixin; Nilsson, Line;

    2015-01-01

    In mammals, glycogen synthase kinase (GSK)3 comprises GSK3α and GSK3β isoforms. GSK3β has been shown to play a role in the ability of kidneys to concentrate urine by regulating vasopressin-mediated water permeability of collecting ducts, whereas the role of GSK3α has yet to be discerned....... To investigate the role of GSK3α in urine concentration, we compared GSK3α knockout (GSK3αKO) mice with wild-type (WT) littermates. Under normal conditions, GSK3αKO mice had higher water intake and urine output. GSK3αKO mice also showed reduced urine osmolality and aquaporin-2 levels but higher urinary...... vasopressin. When water deprived, they failed to concentrate their urine to the same level as WT littermates. The addition of 1-desamino-8-d-arginine vasopressin to isolated inner medullary collecting ducts increased the cAMP response in WT mice, but this response was reduced in GSK3αKO mice, suggesting...

  2. Evidence accumulation for spatial reasoning

    Science.gov (United States)

    Matsuyama, T.; Hwang, V. S. S.; Davis, L. S.

    1984-01-01

    The evidence accumulation proces of an image understanding system is described enabling the system to perform top-down(goal-oriented) picture processing as well as bottom-up verification of consistent spatial relations among objects.

  3. Cystathionine accumulation in Saccharomyces cerevisiae.

    OpenAIRE

    Ono, B; Suruga, T; Yamamoto, M.; Yamamoto, S.; Murata, K; Kimura, A; Shinoda, S; Ohmori, S.

    1984-01-01

    A cysteine-dependent strain of Saccharomyces cerevisiae and its prototrophic revertants accumulated cystathionine in cells. The cystathionine accumulation was caused by a single mutation having a high incidence of gene conversion. The mutation was designated cys3 and was shown to cause loss of gamma-cystathionase activity. Cysteine dependence of the initial strain was determined by two linked and interacting mutations, cys3 and cys1 . Since cys1 mutations cause a loss of serine acetyltransfer...

  4. Gain of function AMP-activated protein kinase γ3 mutation (AMPKγ3R200Q) in pig muscle increases glycogen storage regardless of AMPK activation.

    Science.gov (United States)

    Scheffler, Tracy L; Park, Sungkwon; Roach, Peter J; Gerrard, David E

    2016-06-01

    Chronic activation of AMP-activated protein kinase (AMPK) increases glycogen content in skeletal muscle. Previously, we demonstrated that a mutation in the ryanodine receptor (RyR1(R615C)) blunts AMPK phosphorylation in longissimus muscle of pigs with a gain of function mutation in the AMPKγ3 subunit (AMPKγ3(R200Q)); this may decrease the glycogen storage capacity of AMPKγ3(R200Q) + RyR1(R615C) muscle. Therefore, our aim in this study was to utilize our pig model to understand how AMPKγ3(R200Q) and AMPK activation contribute to glycogen storage and metabolism in muscle. We selected and bred pigs in order to generate offspring with naturally occurring AMPKγ3(R200Q), RyR1(R615C), and AMPKγ3(R200Q) + RyR1(R615C) mutations, and also retained wild-type littermates (control). We assessed glycogen content and parameters of glycogen metabolism in longissimus muscle. Regardless of RyR1(R615C), AMPKγ3(R200Q) increased the glycogen content by approximately 70%. Activity of glycogen synthase (GS) without the allosteric activator glucose 6-phosphate (G6P) was decreased in AMPKγ3(R200Q) relative to all other genotypes, whereas both AMPKγ3(R200Q) and AMPKγ3(R200Q) + RyR1(R615C) muscle exhibited increased GS activity with G6P. Increased activity of GS with G6P was not associated with increased abundance of GS or hexokinase 2. However, AMPKγ3(R200Q) enhanced UDP-glucose pyrophosphorylase 2 (UGP2) expression approximately threefold. Although UGP2 is not generally considered a rate-limiting enzyme for glycogen synthesis, our model suggests that UGP2 plays an important role in increasing flux to glycogen synthase. Moreover, we have shown that the capacity for glycogen storage is more closely related to the AMPKγ3(R200Q) mutation than activity. PMID:27302990

  5. The difference between the mechanism of 67Ga accumulation and 59Fe accumulation into cultured tumor cells

    International Nuclear Information System (INIS)

    It is well known that the mechanism of 67Ga accumulation into tumor cells is mediated with transferrin receptor as well as iron. The present study was designed to explore the difference between the mechanism of gallium accumulation and that of iron by using mouse leukemic cell line L5178Y. When monensin which inhibit the recycle of transferrin receptor was added to the incubated system, accumulation of 59Fe and 67Ga was clearly diminished compared with that of control. However, inhibition of 59Fe accumulation was more remarkable than that of 67Ga. Furthermore, monensin has a action of Na+ ionophore which decrease Na+ gradient between the inside and the outside of the plasma membrane. Following administration of monensin, 67Ga accumulation was diminished according to the loss of the Na+ gradient. On the other hand, following administration of valinomycin, 67Ga accumulation was not affected by the loss of the K+ gradient. From these results, it was suggested that the mechanism of 67Ga accumulation into tumor cells differed from that of 59Fe and transferrin receptor and Na+ gradient of tumor cells played an important role on 67Ga accumulation into tumor cells. (author)

  6. Effect of exhaustive ultra-endurance exercise in muscular glycogen and both Alpha1 and Alpha2 Ampk protein expression in trained rats.

    Science.gov (United States)

    Tarini, V A F; Carnevali, L C; Arida, R M; Cunha, C A; Alves, E S; Seeleander, M C L; Schmidt, B; Faloppa, F

    2013-09-01

    Glycogen is the main store of readily energy in skeletal muscle and plays a key role in muscle function, demonstrated by the inability to sustain prolonged high-intensity exercise upon depletion of these glycogen stores. With prolonged exercise, glycogen depletion occurs and 5'-AMP-activated protein kinase (AMPK), a potent regulator of muscle metabolism and gene expression, is activated promoting molecular signalling that increases glucose uptake by muscular skeletal cells. The aim of this study was primarily to determine the effect of ultra-endurance exercise on muscle glycogen reserves and secondly to verify the influence of this type of exercise on AMPK protein expression. Twenty-four male Wistar rats, 60 days old, were divided into four experimental groups: sedentary, sedentary exhausted (SE), endurance trained (T) and endurance trained exhausted (TE). The animals ran for 10 to 90 min/day, 5 days/week, for 12 weeks to attain trained status. Rats were killed immediately after the exhaustion protocol, which consisted of running on a treadmill (at approximately 60% Vmax until exhaustion). Optical density of periodic acid-Schiff was detected and glycogen depletion observed predominantly in type I muscle fibres of the TE group and in both type I and II muscle fibres in the SE group. Plasma glucose decreased only in the TE group. Hepatic glycogen was increased in T group and significantly depleted in TE group. AMPK protein expression was significantly elevated in TE and T groups. In conclusion, acute exhaustive ultra-endurance exercise promoted muscle glycogen depletion. It seems that total AMPK protein and gene expression is more influenced by status training. PMID:23184732

  7. Regulation of glycogen synthase kinase-3{beta} (GSK-3{beta}) after ionizing radiation; Regulation der Glykogen Synthase Kinase-3{beta} (GSK-3{beta}) nach ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, K.A.

    2006-12-15

    Glycogen Synthase Kinase-3{beta} (GSK-3{beta}) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3{beta} by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3{beta} at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3{beta} serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKB{beta}, is required for phosphorylation of GSK- 3{beta} at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3{beta} at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3{beta} in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer

  8. PROGRESS IN STUDIES ON ICE ACCUMULATION IN RIVER BENDS

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; CHEN Pang-pang; SUI Jue-yi

    2011-01-01

    River ice is an important hydraulic element in temperate and polar environments and would affect hydrodynamic conditions of rivers through changes both in the boundary conditions and the thermal regime.The river bend has been reported as the common location for the initiation of ice jams because the water flow along a river bend is markedly affected by the channel curvature.In this article,the experimental studies about the ice accumulation in a river bend are reviewed.Based on experiments conducted so far,the criteria for the formation of ice jams in the river bend,the mechanisms of the ice accumulation in the river bend and the thickness profile of the ice accumulation in the river bend are discussed.The k- ε two-equation turbulence model is used to simulate the ice accumulation under an ice cover along a river bend.A formula is proposed for describing the deformation of the ice jam bottom.Our results indicate that all simulated thickness of the ice accumulation agrees reasonably well with the measured thickness of the ice accumulation in the laboratory.

  9. Glycogen synthase kinase-3 in the etiology and treatment of mood disorders

    Directory of Open Access Journals (Sweden)

    Richard Scott Jope

    2011-08-01

    Full Text Available The mood disorders major depressive disorder and bipolar disorder are prevalent, are inadequately treated, and little is known about their etiologies. A better understanding of the causes of mood disorders would benefit from improved animal models of mood disorders, which now rely on behavioral measurements. This review considers the limitations in relating measures of rodent behaviors to mood disorders, and the evidence from behavioral assessments indicating that glycogen synthase kinase-3 (GSK3 dysregulation promotes mood disorders and is a potential target for treating mood disorders. The classical mood stabilizer lithium was identified by studying animal behaviors and later was discovered to be an inhibitor of GSK3. Several mood-relevant behavioral effects of lithium in rodents have been identified, and most have now been shown to be due to its inhibition of GSK3. An extensive variety of pharmacological and molecular approaches for manipulating GSK3 are discussed, the results of which strongly support the proposal that inhibition of GSK3 reduces both depression-like and manic-like behaviors. Studies in human postmortem brain and peripheral cells also have identified correlations between alterations in GSK3 and mood disorders. Evidence is reviewed that depression may be associated with impaired inhibitory control of GSK3, and mania by hyper-stimulation of GSK3. Taken together, these studies provide substantial support for the hypothesis that inhibition of GSK3 activity is therapeutic for mood disorders. Future research should identify the causes of dysregulated GSK3 in mood disorders and the actions of GSK3 that contribute to these diseases.

  10. Inhibition of glycogen synthase kinase-3 reduces L-DOPA-induced neurotoxicity

    International Nuclear Information System (INIS)

    The neurotoxicity of L-3,4-dihydroxyphenylalanine (L-DOPA), used for the treatment of Parkinson's disease, remains controversial. Although there are many reports suggesting that long-term treatment of L-DOPA causes neuronal death, an increasing body of recent evidence has proposed that L-DOPA might be neuroprotective rather than neurotoxic. We investigated the effect of L-DOPA on neuronally differentiated PC12 (nPC12) cells by treating cells with various concentrations of L-DOPA for 24 h. We also studied whether glycogen synthase kinase (GSK)-3 activation is related to L-DOPA-induced neurotoxicity by simultaneously treating cells with several concentrations of L-DOPA and a GSK-3 inhibitor for 24 h. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, trypan blue staining, cell counting kit-8, and DAPI staining all showed that L-DOPA decreased nPC12 cell viability at high concentrations. In addition, 100 μM L-DOPA treatment significantly increased the activity of GSK-3 and death signals including cytochrome c, activated caspase-3 and cleaved PARP, and decreased survival signals including heat shock transcription factor-1 in a concentration-dependent manner. Treatment with GSK-3 inhibitor VIII or lithium chloride prevented L-DOPA-induced cell death. Together, these results suggest that L-DOPA induces neuronal cell death at high concentrations and that the neurotoxic effect of L-DOPA might be mediated in part by GSK-3 activation

  11. Lauric acid production in a glycogen-less Synechococcus sp. PCC 7002 mutant

    Directory of Open Access Journals (Sweden)

    Victoria H. Work

    2015-04-01

    Full Text Available The cyanobacterium Synechococcus sp. PCC 7002 was genetically engineered to synthesize biofuel compatible medium-chain fatty acids during photoautotrophic growth. Expression of a heterologous lauroyl-acyl carrier protein (C12:0-ACP thioesterase with concurrent deletion of the endogenous putative acyl-ACP synthetase led to secretion of transesterifiable C12:0 fatty acid in CO2-supplemented batch cultures. When grown at steady state over a range of light intensities in an LED turbidostat photobioreactor, the C12-secreting mutant exhibited a modest reduction in growth rate and increased O2 evolution relative to the wildtype. Inhibition of i glycogen synthesis by deletion of the glgC-encoded ADP-glucose pyrophosphorylase (AGPase, and ii protein synthesis by nitrogen deprivation were investigated as potential mechanisms for metabolite redistribution to increase fatty acid synthesis. Deletion of AGPase led to a ten-fold decrease in reducing carbohydrates and secretion of organic acids during nitrogen deprivation consistent with an energy spilling phenotype. When the carbohydrate-deficient background (∆glgC was modified for C12 secretion, no increase in C12 was achieved during nutrient replete growth, and no C12 was recovered from any strain upon nitrogen deprivation under the conditions used. At steady state, the growth rate of the ∆glgC strain saturated at a lower light intensity than the wildtype, but O2 evolution was not compromised and became increasingly decoupled from growth rate with rising irradiance. Photophysiological properties of the ∆glgC strain suggest energy dissipation from photosystem II and reconfiguration of electron flow at the level of the plastoquinone pool.

  12. Nuclear glycogen synthase kinase-3 β (GSK-3) in Rhipicephalus (Boophilus) microplus tick embryogenesis

    International Nuclear Information System (INIS)

    Full text: Glycogen synthase kinase-3 (GSK3) is recognized as a key component of a large number of cellular processes and diseases. Several mechanisms play a part in controlling the actions of GSK3, including phosphorylation, protein complex formation, and subcellular distribution. Recent observations point to functions for phosphorylases several transcription factors in the nucleus. Also, GSK3b participate of the canonical W nt signalling pathway, which has been studied intensively in embryonic and cancer cells. Like in many other signaling pathways, most components in W nt signal transduction were highly conserved during the evolution. More than 40 proteins have been reported to be phosphorylated by GSK3, including over a dozen transcription factors. Although the mechanisms regulating GSK3 are not fully understood, precise control appears to be achieved by a combination of phosphorylation, localization, and interactions with GSK3-binding proteins. Although GSK3 is traditionally considered a cytosolic protein, it is also present in nuclei. Nuclear GSK3 is particularly interesting because of the many transcription factors that it regulates enabling GSK3 to influence many signaling pathways that converge on these transcription factors, thereby regulating the expression of many genes. Our group identified that GSK-3 β could be detected in different stage eggs of R. micro plus. In this work we detected the GSK-3 in isolated nuclear fraction from the egg homogenates of R. micro plus by western-blot analysis, using anti-GSK- 3 β antibodies. The enzyme activity was also detected radiochemically throughout embryogenesis in same fraction. The GSK-3 activity was inhibiting by using SB 216763 (selective molecule inhibitors of GSK-3). Taken together our results suggest that GSK-3 β isoform probably is involved in gene transcription factors during R. micro plus embryo development

  13. Phylogenetic diversification of glycogen synthase kinase 3/SHAGGY-like kinase genes in plants

    Directory of Open Access Journals (Sweden)

    Soltis Pamela S

    2006-02-01

    Full Text Available Abstract Background The glycogen synthase kinase 3 (GSK3/SHAGGY-like kinases (GSKs are non-receptor serine/threonine protein kinases that are involved in a variety of biological processes. In contrast to the two members of the GSK3 family in mammals, plants appear to have a much larger set of divergent GSK genes. Plant GSKs are encoded by a multigene family; analysis of the Arabidopsis genome revealed the existence of 10 GSK genes that fall into four major groups. Here we characterized the structure of Arabidopsis and rice GSK genes and conducted the first broad phylogenetic analysis of the plant GSK gene family, covering a taxonomically diverse array of algal and land plant sequences. Results We found that the structure of GSK genes is generally conserved in Arabidopsis and rice, although we documented examples of exon expansion and intron loss. Our phylogenetic analyses of 139 sequences revealed four major clades of GSK genes that correspond to the four subgroups initially recognized in Arabidopsis. ESTs from basal angiosperms were represented in all four major clades; GSK homologs from the basal angiosperm Persea americana (avocado appeared in all four clades. Gymnosperm sequences occurred in clades I, III, and IV, and a sequence of the red alga Porphyra was sister to all green plant sequences. Conclusion Our results indicate that (1 the plant-specific GSK gene lineage was established early in the history of green plants, (2 plant GSKs began to diversify prior to the origin of extant seed plants, (3 three of the four major clades of GSKs present in Arabidopsis and rice were established early in the evolutionary history of extant seed plants, and (4 diversification into four major clades (as initially reported in Arabidopsis occurred either just prior to the origin of the angiosperms or very early in angiosperm history.

  14. Pharmaceutical inhibition of glycogen synthetase kinase 3 beta suppresses wear debris-induced osteolysis.

    Science.gov (United States)

    Geng, Dechun; Wu, Jian; Shao, Hongguo; Zhu, Shijun; Wang, Yijun; Zhang, Wen; Ping, Zichuan; Hu, Xuanyang; Zhu, Xuesong; Xu, Yaozeng; Yang, Huilin

    2015-11-01

    Aseptic loosening is associated with the development of wear debris-induced peri-implant osteolytic bone disease caused by an increased osteoclastic bone resorption and decreased osteoblastic bone formation. However, no effective measures for the prevention and treatment of peri-implant osteolysis currently exist. The aim of this study was to determine whether lithium chloride (LiCl), a selective inhibitor of glycogen synthetase kinase 3 beta (GSK-3β), mitigates wear debris-induced osteolysis in a murine calvarial model of osteolysis. GSK-3β is activated by titanium (Ti) particles, and implantation of Ti particles on the calvarial surface in C57BL/6 mice resulted in osteolysis caused by an increase in the number of osteoclasts and a decrease in the number of osteoblasts. Mice implanted with Ti particles were gavage-fed LiCl (50 or 200 mg kg(-1)d(-1)), 6 days per week for 2 weeks. The LiCl treatment significantly inhibited GSK-3β activity and increased β-catenin and axin-2 expression in a dose-dependent manner, dramatically mitigating the Ti particle-induced suppression of osteoblast numbers and the expression of bone formation markers. Finally, we demonstrated that inhibition of GSK-3β suppresses osteoclast differentiation and reduces the severity of Ti particle-induced osteolysis. The results of this study indicate that Ti particle-induced osteolysis is partly dependent on GSK-3β and, therefore, the canonical Wnt signaling pathway. This suggests that selective inhibitors of GSK-3β such as LiCl may help prevent and treat wear debris-induced osteolysis. PMID:26275858

  15. Regulation by glycogen synthase kinase-3 of inflammation and T cells in CNS diseases

    Directory of Open Access Journals (Sweden)

    Eleonore Beurel

    2011-08-01

    Full Text Available Elevated markers of neuroinflammation have been found to be associated with many psychiatric and neurodegenerative diseases, such as mood disorders, Alzheimer's disease, and multiple sclerosis. Since neuroinflammation is thought to contribute to the pathophysiology of these diseases and to impair responses to therapeutic interventions and recovery, it is important to identify mechanisms that regulate neuroinflammation and potential targets for controlling neuroinflammation. Recent findings have demonstrated that glycogen synthase kinase-3 (GSK3 is an important regulator of both the innate and adaptive immune systems' contributions to inflammation. Studies of the innate immune system have shown that inhibitors of GSK3 profoundly alter the repertoire of cytokines that are produced both by peripheral and central cells, reducing proinflammatory cytokines and increasing anti-inflammatory cytokines. Furthermore, inhibitors of GSK3 promote tolerance to inflammatory stimuli, reducing inflammatory cytokine production upon repeated exposure. Studies of the adaptive immune system have shown that GSK3 regulates the production of cytokines by T cells and the differentiation of T cells to subtypes, particularly Th17 cells. Regulation of transcription factors by GSK3 appears to play a prominent role in its regulation of immune responses, including of NF-κB, cyclic AMP response element binding protein (CREB, and signal transducer and activator of transcription-3 (STAT3. In vivo studies have shown that GSK3 inhibitors ameliorate clinical symptoms of both peripheral and central inflammatory diseases, particularly experimental autoimmune encephalomyelitis (EAE, the animal model of multiple sclerosis. Therefore, the development and application of GSK3 inhibitors may provide a new therapeutic strategy to reduce neuroinflammation associated with many CNS diseases.

  16. Nuclear glycogen synthase kinase-3 {beta} (GSK-3) in Rhipicephalus (Boophilus) microplus tick embryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Mentzingen, Leticia; Andrade, Josiana G. de; Logullo, Carlos [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Biociencias e Biotecnologia. Lab. de Quimica e Funcao de Proteinas e Peptideos (LQFPP); Andrade, Caroline P. de; Vaz Junior, Itabajara [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Biotecnologia

    2008-07-01

    Full text: Glycogen synthase kinase-3 (GSK3) is recognized as a key component of a large number of cellular processes and diseases. Several mechanisms play a part in controlling the actions of GSK3, including phosphorylation, protein complex formation, and subcellular distribution. Recent observations point to functions for phosphorylases several transcription factors in the nucleus. Also, GSK3b participate of the canonical W nt signalling pathway, which has been studied intensively in embryonic and cancer cells. Like in many other signaling pathways, most components in W nt signal transduction were highly conserved during the evolution. More than 40 proteins have been reported to be phosphorylated by GSK3, including over a dozen transcription factors. Although the mechanisms regulating GSK3 are not fully understood, precise control appears to be achieved by a combination of phosphorylation, localization, and interactions with GSK3-binding proteins. Although GSK3 is traditionally considered a cytosolic protein, it is also present in nuclei. Nuclear GSK3 is particularly interesting because of the many transcription factors that it regulates enabling GSK3 to influence many signaling pathways that converge on these transcription factors, thereby regulating the expression of many genes. Our group identified that GSK-3 {beta} could be detected in different stage eggs of R. micro plus. In this work we detected the GSK-3 in isolated nuclear fraction from the egg homogenates of R. micro plus by western-blot analysis, using anti-GSK- 3 {beta} antibodies. The enzyme activity was also detected radiochemically throughout embryogenesis in same fraction. The GSK-3 activity was inhibiting by using SB 216763 (selective molecule inhibitors of GSK-3). Taken together our results suggest that GSK-3 {beta} isoform probably is involved in gene transcription factors during R. micro plus embryo development.

  17. A metabolic link between mitochondrial ATP synthesis and liver glycogen metabolism: NMR study in rats re-fed with butyrate and/or glucose

    Directory of Open Access Journals (Sweden)

    Beauvieux Marie-Christine

    2011-06-01

    Full Text Available Abstract Background Butyrate, end-product of intestinal fermentation, is known to impair oxidative phosphorylation in rat liver and could disturb glycogen synthesis depending on the ATP supplied by mitochondrial oxidative phosphorylation and cytosolic glycolysis. Methods In 48 hr-fasting rats, hepatic changes of glycogen and total ATP contents and unidirectional flux of mitochondrial ATP synthesis were evaluated by ex vivo 31P NMR immediately after perfusion and isolation of liver, from 0 to 10 hours after force-feeding with (butyrate 1.90 mg + glucose 14.0 mg.g-1 body weight or isocaloric glucose (18.2 mg.g-1 bw; measurements reflected in vivo situation at each time of liver excision. The contribution of energetic metabolism to glycogen metabolism was estimated. Results A net linear flux of glycogen synthesis (~11.10 ± 0.60 μmol glucosyl units.h-1.g-1 liver wet weight occurred until the 6th hr post-feeding in both groups, whereas butyrate delayed it until the 8th hr. A linear correlation between total ATP and glycogen contents was obtained (r2 = 0.99 only during net glycogen synthesis. Mitochondrial ATP turnover, calculated after specific inhibition of glycolysis, was stable (~0.70 ± 0.25 μmol.min-1.g-1 liver ww during the first two hr whatever the force-feeding, and increased transiently about two-fold at the 3rd hr in glucose. Butyrate delayed the transient increase (1.80 ± 0.33 μmol.min-1.g-1 liver ww to the 6th hr post-feeding. Net glycogenolysis always appeared after the 8th hr, whereas flux of mitochondrial ATP synthesis returned to near basal level (0.91 ± 0.19 μmol.min-1.g-1 liver ww. Conclusion In liver from 48 hr-starved rats, the energy need for net glycogen synthesis from exogenous glucose corresponds to ~50% of basal mitochondrial ATP turnover. The evidence of a late and transient increase in mitochondrial ATP turnover reflects an energetic need, probably linked to a glycogen cycling. Butyrate, known to reduce oxidative

  18. The design of potential antidiabetic drugs: experimental investigation of a number of beta-D-glucose analogue inhibitors of glycogen phosphorylase.

    Science.gov (United States)

    Oikonomakos, N G; Kontou, M; Zographos, S E; Tsitoura, H S; Johnson, L N; Watson, K A; Mitchell, E P; Fleet, G W; Son, J C; Bichard, C J

    1994-01-01

    alpha-D-glucose is a weak inhibitor (Ki = 1.7 mM) of glycogen phosphorylase (GP) and acts as physiological regulator of hepatic glycogen metabolism; it binds to GP at the catalytic site and stabilizes the inactive T state of the enzyme promoting the action of protein phosphatase 1 and stimulating glycogen synthase. The three-dimensional structures of T state rabbit muscle GPb and the GPb-alpha-D-glucose complex have been exploited in the design of better regulators of GP that could shift the balance between glycogen synthesis and glycogen degradation in favour of the former. Close examination of the catalytic site with alpha-D-glucose bound shows that there is an empty pocket adjacent to the beta-1-C position. beta-D-glucose is a poorer inhibitor (Ki = 7.4 mM) than alpha-D-glucose, but mutarotation has prevented the binding of beta-D-glucose in T state GP crystals. A series of beta-D-glucose analogues has been designed and tested in kinetic and crystallographic experiments. Several compounds have been discovered that have an increased affinity for GP than the parent compound. PMID:7867660

  19. Effect of in ovo feeding egg white protein, beta-hydroxy-beta-methylbutyrate, and carbohydrates on glycogen status and neonatal growth of turkeys.

    Science.gov (United States)

    Foye, O T; Uni, Z; Ferket, P R

    2006-07-01

    In ovo feeding (IOF), injecting dietary components into the amnion about 1 d prior to internal pipping, may enhance growth by altering glycogen status. This hypothesis was evaluated with 5 IOF solutions containing protein, beta-hydroxy-beta-methylbutyrate (HMB), and carbohydrate. Four IOF treatments were arranged as a factorial of 2 levels of egg white protein (EWP; 0 and 18%) and 2 levels of HMB (0 and 0.1%). An IOF solution of carbohydrates (S; 20% dextrin and 3% maltose) was evaluated for contrast purposes. At 23 d of incubation, 1.5 mL of IOF solution was injected into the amnion of 100 eggs per treatment. At hatch, feed and water were provided ad libitum. At hatch and 3 and 7 d of age, BW were determined, and 10 poults per treatment were sampled to determine liver (LG) and pectoralis muscle (PC) glycogen content. Poults on IOF treatments A (18% EWP), B (18% EWP + HMB), and D (HMB) weighed 6.0, 2.7, and 3.3% more than the controls at hatch, respectively (P ovo had enhanced total PC glycogen over controls, whereas poults on treatment A had less total PC glycogen than controls (P < 0.05). The results of this experiment demonstrate that IOF of A or S poults may enhance hatch BW and glycogen status of poults during the neonatal period by inclusion of HMB. PMID:16830858

  20. Affect Regulation

    DEFF Research Database (Denmark)

    Pedersen, Signe Holm; Poulsen, Stig Bernt; Lunn, Susanne

    2014-01-01

    Gergely and colleagues’ state that their Social Biofeedback Theory of Parental Affect Mirroring” can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parenta...