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Sample records for affect plasma arginine

  1. The T1405N carbamoyl phosphate synthetase polymorphism does not affect plasma arginine concentrations in preterm infants.

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    Rob M J Moonen

    Full Text Available BACKGROUND: A C-to-A nucleotide transversion (T1405N in the gene that encodes carbamoyl-phosphate synthetase 1 (CPS1 has been associated with changes in plasma concentrations of L-arginine in term and near term infants but not in adults. In preterm infants homozygosity for the CPS1 Thr1405 variant (CC genotype was associated with an increased risk of having necrotizing enterocolitis (NEC. Plasma L-arginine concentrations are decreased in preterm infants with NEC. AIM: To examine the putative association between the CPS1 T1405N polymorphism and plasma arginine concentrations in preterm infants. METHODS: Prospective multicenter cohort study. Plasma and DNA samples were collected from 128 preterm infants (<30 weeks between 6 and 12 hours after birth. Plasma amino acid and CPS1 T1405N polymorphism analysis were performed. RESULTS: Distribution of genotypes did not differ between the preterm (CC:CA:AA = 55.5%:33.6%:10.9%, n = 128 and term infants (CC:CA:AA = 54.2%:35.4%:10.4%, n = 96. There was no association between the CPS1 genotype and plasma L-arginine or L-citrulline concentration, or the ornithine to citrulline ratio, which varies inversely with CPS1 activity. Also the levels of asymmetric dimethylarginine, and symmetric dimethylarginine were not significantly different among the three genotypes. CONCLUSIONS: The present study in preterm infants did not confirm the earlier reported association between CPS1 genotype and L-arginine levels in term infants.

  2. Effects of dietary salt intake on plasma arginine.

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    Kitiyakara, C; Chabrashvili, T; Jose, P; Welch, W J; Wilcox, C S

    2001-04-01

    Because L-arginine is degraded by hepatic arginase to ornithine and urea and is transported by the regulated 2A cationic amino acid y(+) transporter (CAT2A), hepatic transport may regulate plasma arginine concentration. Groups of rats (n = 6) were fed a diet of either low salt (LS) or high salt (HS) for 7 days to test the hypothesis that dietary salt intake regulates plasma arginine concentration and renal nitric oxide (NO) generation by measuring plasma arginine and ornithine concentrations, renal NO excretion, and expression of hepatic CAT2A, and arginase. LS rats had lower excretion of NO metabolites and cGMP, lower plasma arginine concentration (LS: 83 +/- 7 vs. HS: 165 +/- 10 micromol/l, P plasma ornithine concentration (LS: 82 +/- 6 vs. HS: 66 +/- 4 micromol/l, P plasma arginine concentration with increased plasma ornithine concentration and urea excretion during LS indicates increased arginine metabolism by arginase. This cannot be ascribed to changes in hepatic arginase expression but may be a consequence of increased hepatic arginine uptake via CAT2A. PMID:11247829

  3. Arginine affects appetite via nitric oxide in ducks.

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    Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

    2014-08-01

    The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P Pekin ducks. PMID:24902706

  4. Dietary arginine affects energy metabolism through polyamine turnover in juvenile Atlantic salmon (Salmo salar).

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    Andersen, Synne M; Holen, Elisabeth; Aksnes, Anders; Rønnestad, Ivar; Zerrahn, Jens-Erik; Espe, Marit

    2013-12-14

    In the present study, quadruplicate groups of juvenile Atlantic salmon (Salmo salar) were fed plant protein-based diets with increasing arginine inclusions (range 28·8-37·4 g/kg DM) to investigate whether arginine supplementation affects growth and lipid accumulation through an elevated polyamine turnover. Dietary lysine was held at a constant concentration, just below the requirement. All other amino acids were balanced and equal in the diets. Arginine supplementation increased protein and fat accretion, without affecting the hepatosomatic or visceralsomatic indices. Dietary arginine correlated with putrescine in the liver (R 0·78, P= 0·01) and with ornithine in the muscle, liver and plasma (P= 0·0002, 0·003 and 0·0002, respectively). The mRNA of ornithine decarboxylase, the enzyme producing putrescine, was up-regulated in the white adipose tissue of fish fed the high-arginine inclusion compared with those fed the low-arginine diet. Concomitantly, spermidine/spermine-(N1)-acetyltransferase, the rate-limiting enzyme for polyamine turnover that consumes acetyl-CoA, showed an increased activity in the liver of fish fed the arginine-supplemented diets. In addition, lower acetyl-CoA concentrations were observed in the liver of fish fed the high-arginine diet, while ATP, which is used in the process of synthesising spermidine and spermine, did not show a similar trend. Gene expression of the rate-limiting enzyme for β-oxidation of long-chain fatty acids, carnitine palmitoyl transferase-1, was up-regulated in the liver of fish fed the high-arginine diet. Taken together, the data support that increased dietary arginine activates polyamine turnover and β-oxidation in the liver of juvenile Atlantic salmon and may act to improve the metabolic status of the fish. PMID:23656796

  5. Metabolomic analysis of plasma and liver from surplus arginine fed Atlantic salmon

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    Andersen, Synne M.; Assaad, Houssein I.; Lin, Gang; Wang, Junjun; Aksnes, Anders; Wu, Guoyao; Espe, Marit

    2016-01-01

    The aim of this study was to determine the metabolic effect of surplus arginine (36.1 g/kg dry matter) compared to a control diet with required arginine (21.1 g/kg dry matter) in adult Atlantic salmon (Salmo salar L.). Although the feeding trial had no significant effect on growth, there were significant differences in the metabolite profile in both plasma and liver in experimental group as compared to the control group. There was increased concentrations of biliverdin, PGF-2 alpha, oxidized glutathione, selenocysteine, two monoacylglycerols and a tripeptide in the liver as well as decreased concentrations of valine and a vitamin D3 metabolite in plasma of arginine supplemented fish. These results indicate that while surplus arginine does not affect growth or body weight, it induces metabolic changes in Atlantic salmon. PMID:25553364

  6. Arginine Depletion by Arginine Deiminase Does Not Affect Whole Protein Metabolism or Muscle Fractional Protein Synthesis Rate in Mice

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    Marini, Juan C.; Didelija, Inka Cajo

    2015-01-01

    Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20) on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (<1 μmol/L), and increased citrulline concentration more than tenfold. Body weight and body composition, however, were not affected by ADI-PEG 20. Despite the depletion of arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas) were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight. PMID:25775142

  7. Low plasma arginine:asymmetric dimethyl arginine ratios predict mortality after intracranial aneurysm rupture

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    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels; Weikop, Pia; Romner, Bertil; Olsen, Niels Vidiendal

    2013-01-01

    Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, predicts mortality in cardiovascular disease and has been linked to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). In this prospective study, we assessed whether circulating ADMA, arginine...

  8. Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

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    Jaja, S I; Ogungbemi, S O; Kehinde, M O; Anigbogu, C N

    2016-06-01

    The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (pNOx] were higher in NSCA subjects (pNOX] in SCA than in NSCA subjects (plow-dose supplementation with l-arginine improved liver function, oxidative stress, plasma arginine concentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects. PMID:27156372

  9. Lysozyme affects the microbial catabolism of free arginine in raw-milk hard cheeses.

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    D'Incecco, P; Gatti, M; Hogenboom, J A; Bottari, B; Rosi, V; Neviani, E; Pellegrino, L

    2016-08-01

    Lysozyme (LZ) is used in several cheese varieties to prevent late blowing which results from fermentation of lactate by Clostridium tyrobutyricum. Side effects of LZ on lactic acid bacteria population and free amino acid pattern were studied in 16 raw-milk hard cheeses produced in eight parallel cheese makings conducted at four different dairies using the same milk with (LZ+) or without (LZ-) addition of LZ. The LZ-cheeses were characterized by higher numbers of cultivable microbial population and lower amount of DNA arising from lysed bacterial cells with respect to LZ + cheeses. At both 9 and 16 months of ripening, Lactobacillus delbrueckii and Lactobacillus fermentum proved to be the species mostly affected by LZ. The total content of free amino acids indicated the proteolysis extent to be characteristic of the dairy, regardless to the presence of LZ. In contrast, the relative patterns showed the microbial degradation of arginine to be promoted in LZ + cheeses. The data demonstrated that the arginine-deiminase pathway was only partially adopted since citrulline represented the main product and only trace levels of ornithine were found. Differences in arginine degradation were considered for starter and non-starter lactic acid bacteria, at different cheese ripening stages. PMID:27052697

  10. Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training.

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    Greer, Beau K; Jones, Brett T

    2011-07-01

    Dietary supplement companies claim that arginine supplements acutely enhance skeletal muscular endurance. The purpose of this study was to determine whether acute arginine α-ketoglutarate supplementation (AAKG) will affect local muscle endurance of the arm and shoulder girdle or the blood pressure (BP) response to anaerobic exercise. Twelve trained college-aged men (22.6 ± 3.8 years) performed 2 trials of exercise separated by at least 1 week. At 4 hours before, and 30 minutes before exercise, a serving of an AAKG supplement (3,700 mg arginine alpha-ketoglutarate per serving) or placebo was administered. Resting BP was assessed pre-exercise after 16 minutes of seated rest, and 5 and 10 minutes postexercise. Three sets each of chin-ups, reverse chin-ups, and push-ups were performed to exhaustion with 3 minutes of rest between each set. Data were analyzed using repeated-measures analysis of variance and paired t-tests. The AAKG supplementation did not improve muscle endurance or significantly affect the BP response to anaerobic work. Subjects performed fewer total chin-ups (23.75 ± 6.38 vs. 25.58 ± 7.18) and total trial repetitions (137.92 ± 28.18 vs. 141.08 ± 28.57) in the supplement trial (p ≤ 0.05). Subjects executed fewer reverse chin-ups (5.83 ± 1.85 vs. 6.75 ± 2.09) during set 2 after receiving the supplement as compared to the placebo (p AAKG supplementation may hinder muscular endurance, the use of these supplements before resistance training should be questioned. PMID:21399536

  11. Plasma arginine vasopressin response to water load during labour

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    To find out whether plasma vasopressin (Psub(AVP)) response to a water load during pregnancy is inappropriately high, as had been speculated, we measured Psub(AVP)by radioimmunoassay in 30 women at the time of delivery. Ten women had received infusion of aqueous glucose solution during labour for hydration (GW group); another ten received infusion of glucose solution as a vehicle for oxytocin (IOT group), and ten women did not receive any intrapartum intravenous fluid therapy (controls). Serum sodium and osmolality were also determined in all the subjects. Psub(AVP) levels were significantly lower in GW (0.70 +- 0.4 pg/ml) and OT groups (0.7 +- 0.6 pg/ml) (P<0.05). Significant negative correlation was seen between the amount of glucose solution infused and levels of Psub(AVP) (r = -0.66; P<0.01), while a significant positive correlation was seen between Psub(AVP) and serum sodium (r = 0.61; P<0.01). These findings suggest that during labour, the physiological relationship between serum osmolality and Psub(AVP) in intact, and the infusion of a water load in the form of aqueous glucose solution is attended by an expected lowering of Psub(AVP). We infer that inappropriate ADH response is not the cause of water retention and hyponatremia often seen in women receiving aqueous glucose solution during labor. (author)

  12. Plasma arginine vasopressin response to water load during labour

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    Singhi, S. (West Indies Univ., Mona (Jamaica). Dept. of Child Health); Parshad, O. (West Indies Univ., Mona (Jamaica). Dept. of Physiology)

    1985-02-01

    To find out whether plasma vasopressin (Psub(AVP)) response to a water load during pregnancy is inappropriately high, as had been speculated, we measured Psub(AVP)by radioimmunoassay in 30 women at the time of delivery. Ten women had received infusion of aqueous glucose solution during labour for hydration (GW group); another ten received infusion of glucose solution as a vehicle for oxytocin (IOT group), and ten women did not receive any intrapartum intravenous fluid therapy (controls). Serum sodium and osmolality were also determined in all the subjects. Psub(AVP) levels were significantly lower in GW (0.70 +- 0.4 pg/ml) and OT groups (0.7 +- 0.6 pg/ml) (P < 0.05). Significant negative correlation was seen between the amount of glucose solution infused and levels of Psub(AVP) (r = -0.66; P < 0.01), while a significant positive correlation was seen between Psub(AVP) and serum sodium (r = 0.61; P < 0.01). These findings suggest that during labour, the physiological relationship between serum osmolality and Psub(AVP) in intact, and the infusion of a water load in the form of aqueous glucose solution is attended by an expected lowering of Psub(AVP). We infer that inappropriate ADH response is not the cause of water retention and hyponatremia often seen in women receiving aqueous glucose solution during labor.

  13. Simultaneous measurement of arginine vasopressin and oxytocin in plasma and neurohypophysis by radioimmunoassay

    International Nuclear Information System (INIS)

    Arginine vasopressin (AVP) and oxytocin (OXT) were measured simultaneously in the same sample by specific and sensitive radioimmunoassays (RIAs). The antibodies used did not cross-react to a variety of analogs and related peptides. The extraction procedure using Vycor glass powder resulted in mean recoveries of 84.4% (AVP) and 64.6% (OXT). In both assays, the sensitivity was 1 to 2 pg/ml plasma. A preincubation procedure that depresses plasma levels of both AVP and OXT selectively, provided specific blank values for a given plasma sample. To confirm the validity of the RIAs, dehydration experiments were performed. In rats, the basal levels of plasma AVP and OXT (means: 2,63 pg/ml and 6.80 pg/ml, respectively) are increased significantly after 24 h, 48 h and 72 h of water deprivation. Relationships are presented between both neurohormones in the plasma and neurohypophyses of control and dehydrated animals. As shown in cows, a significant correlation exists between plasma AVP and plasma osmolality but not between plasma OXT and osmolality or plasma AVP and OXT. Basal levels as well as physiological changes in plasma and neurohypophyseal AVP and OXT can be measured by the RIAs described. (author)

  14. Simultaneous measurement of arginine vasopressin and oxytocin in plasma and neurohypophysis by radioimmunoassay

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    Landgraf, R. (Deutsche Hochschule fuer Koerperkultur, Leipzig (German Democratic Republic). Forschungsinstitut Koerperkultur und Sport)

    1981-12-01

    Arginine vasopressin (AVP) and oxytocin (OXT) were measured simultaneously in the same sample by specific and sensitive radioimmunoassays (RIAs). The antibodies used did not cross-react to a variety of analogs and related peptides. The extraction procedure using Vycor glass powder resulted in mean recoveries of 84.4% (AVP) and 64.6% (OXT). In both assays, the sensitivity was 1 to 2 pg/ml plasma. A preincubation procedure that depresses plasma levels of both AVP and OXT selectively, provided specific blank values for a given plasma sample. To confirm the validity of the RIAs, dehydration experiments were performed. In rats, the basal levels of plasma AVP and OXT (means: 2,63 pg/ml and 6.80 pg/ml, respectively) are increased significantly after 24 h, 48 h and 72 h of water deprivation. Relationships are presented between both neurohormones in the plasma and neurohypophyses of control and dehydrated animals. As shown in cows, a significant correlation exists between plasma AVP and plasma osmolality but not between plasma OXT and osmolality or plasma AVP and OXT. Basal levels as well as physiological changes in plasma and neurohypophyseal AVP and OXT can be measured by the RIAs described.

  15. Bioactive products of arginine in sepsis: tissue and plasma composition after LPS and iNOS blockade.

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    Lortie, M J; Ishizuka, S; Schwartz, D; Blantz, R C

    2000-06-01

    Blockade or gene deletion of inducible nitric oxide synthase (iNOS) fails to fully abrogate all the sequelae leading to the high morbidity of septicemia. An increase in substrate uptake may be necessary for the increased production of nitric oxide (NO), but arginine is also a precursor for other bioactive products. Herein, we demonstrate an increase in alternate arginine products via arginine and ornithine decarboxylase in rats given lipopolysaccharide (LPS). The expression of iNOS mRNA in renal tissue was evident 60 but not 30 min post-LPS, yet a rapid decrease in blood pressure was obtained within 30 min that was completely inhibited by selective iNOS blockade. Plasma levels of arginine and ornithine decreased by at least 30% within 60 min of LPS administration, an effect not inhibited by the iNOS blocker L-N(6)(1-iminoethyl)lysine (L-NIL). Significant increases in plasma nitrates and citrulline occurred only 3-4 h post-LPS, an effect blocked by L-NIL pretreatment. The intracellular composition of organs harvested 6 h post-LPS reflected tissue-specific profiles of arginine and related metabolites. Tissue arginine concentration, normally an order of magnitude higher than in plasma, did not decrease after LPS. Pretreatment with L-NIL had a significant impact on the disposition of tissue arginine that was organ specific. These data demonstrate changes in arginine metabolism before and after de novo iNOS activity. Selective blockade of iNOS did not prevent uptake and can deregulate the production of other bioactive arginine metabolites. PMID:10837347

  16. Pharmacological PPARα activation markedly alters plasma turnover of the amino acids glycine, serine and arginine in the rat.

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    Anette Ericsson

    Full Text Available The current study extends previously reported PPARα agonist WY 14,643 (30 µmol/kg/day for 4 weeks effects on circulating amino acid concentrations in rats fed a 48% saturated fat diet. Steady-state tracer experiments were used to examine in vivo kinetic mechanisms underlying altered plasma serine, glycine and arginine levels. Urinary urea and creatinine excretion were measured to assess whole-body amino acid catabolism. WY 14,643 treated animals demonstrated reduced efficiency to convert food consumed to body weight gain while liver weight was increased compared to controls. WY 14,643 raised total amino acid concentration (38%, largely explained by glycine, serine and threonine increases. 3H-glycine, 14C-serine and 14C-arginine tracer studies revealed elevated rates of appearance (Ra for glycine (45.5 ± 5.8 versus 17.4 ± 2.7 µmol/kg/min and serine (21.0 ± 1.4 versus 12.0 ± 1.0 in WY 14,643 versus control. Arginine was substantially decreased (-62% in plasma with estimated Ra reduced from 3.1 ± 0.3 to 1.2 ± 0.2 µmol/kg/min in control versus WY 14,643. Nitrogen excretion over 24 hours was unaltered. Hepatic arginase activity was substantially decreased by WY 14,643 treatment. In conclusion, PPARα agonism potently alters metabolism of several specific amino acids in the rat. The changes in circulating levels of serine, glycine and arginine reflected altered fluxes into the plasma rather than changes in clearance or catabolism. This suggests that PPARα has an important role in modulating serine, glycine and arginine de novo synthesis.

  17. Early change of plasma and cerebrospinal fluid arginine vasopressin in traumatic subarachnoid hemorrhage

    Institute of Scientific and Technical Information of China (English)

    YUAN Zhi-hua; ZHU Jian-yong; HUANG Wei-dong; JIANG Jiu-kun; LU Yuan-qiang; XU Miao; SU Wei; JIANG Ting-ying

    2010-01-01

    Objective:To investigate the changes and effects of arginine vasopressin(AVP)in patients with acute traumatic subarachnoid hemorrhage(tSAH).Methods:The plasma and cerebrospinal fluid(CSF)level of AVP,and intracraniai pressure(ICP)were measured in a total of 21 patients within 24 hours after tSAH.The neurological status of the patients was evaluated by Glasgow Coma Scale(GCS).Correlation between AVP and ICP,CrCS was analyzed respectively.Meanwhile,18 healthy volunteers were recruited as control group.Results:Compared with control group,the levels(pg/ml)of AVP in plasma and CSF((x)±s)in tSAH group were significantly increased within 24 hours(38.72±24.71 vs 4.54±1.38and 34.61±21.43 vs 4.13±1.26,P<0.01),and was remarkably higher in GCS≤8 group than GCS>8 group(50.96±36.81 vs 25.26±12.87 and 44.68±31.72 vs 23.53±10.94,P<0.05).The CSF AVP level was correlated with ICP(r= 0.46,P<0.05),but no statistically significant correlation was found between plasma AVP,CSF AVP and initial GCS(r=-0.29,P>0.05 and r=-0.32,P>0.05,respectively).The ICP(mm Hg)in tSAH patients was elevated and higher in GCS≤8 group than in GCS>8 group(25.9±9.7 vs 17.6±5.2,P<0.05=.Conclusion:Our research suggests that AVP is correlated with the severity of tSAH,and may be involved in the pathophysiological process of brain damage in the early stage after tSAH.It seems that compared with the plasma AVP concentration,CSF AVP is more related to the severity of tSAH.

  18. Arginine-vasopressin marker copeptin is a sensitive plasma surrogate of hypoxic exposure

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    Ostergaard L

    2014-09-01

    Full Text Available Louise Ostergaard,1,2,* Alain Rudiger,3,* Sven Wellmann,2,4,5 Elena Gammella,6 Beatrice Beck-Schimmer,2,3 Joachim Struck,7 Marco Maggiorini,2,8 Max Gassmann,1,2,9 1Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 2Zürich Center for Integrative Human Physiology, 3Institute of Anesthesiology, 4Division of Neonatology, University Hospital Zürich, Zürich, 5Department of Neonatology, University Children's Hospital Basel, Basel, Switzerland; 6Department of Human Morphology and Biomedical Science, University of Milan, Milan, Italy; 7Research Department, B•R•A•H•M•S Biomarkers, Thermo Fisher Scientific, Hennigsdorf, Germany; 8Medical Intensive Care Unit, University Hospital Zürich, Zürich, Switzerland; 9Universidad Peruana Cayetano Heredia, Lima, Peru *These authors contributed equally to this work and share first authorship Background: A reduced oxygen supply puts patients at risk of tissue hypoxia, organ damage, and even death. In response, several changes are activated that allow for at least partial adaptation, thereby increasing the chances of survival. We aimed to investigate whether the arginine vasopressin marker, copeptin, can be used as a marker of the degree of acclimatization/adaptation in rats exposed to hypoxia. Methods: Sprague-Dawley rats were exposed to 10% oxygen for up to 48 hours. Arterial and right ventricular pressures were measured, and blood gas analysis was performed at set time points. Pulmonary changes were investigated by bronchoalveolar lavage, wet and dry weight measurements, and lung histology. Using a newly developed specific rat copeptin luminescence immunoassay, the regulation of vasopressin in response to hypoxia was studied, as was atrial natriuretic peptide (ANP by detecting mid-regional proANP. Results: With a decreasing oxygen supply, the rats rapidly became cyanotic and inactive. Despite continued exposure to 10% oxygen, all animals recuperated within 16 hours and

  19. Functional variation in the arginine vasopressin 2 receptor as a modifier of human plasma von Willebrand factor levels

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    Nossent, Anne Yaël; Robben, J H; Deen, P M T; Vos, H L; Rosendaal, F R; Doggen, C J M; Hansen, J L; Sheikh, S P; Bertina, R M; Eikenboom, J C J

    2010-01-01

    -green fluorescent protein (GFP) cells, which is in accordance with increased levels of VWF propeptide associated with the 12E variant. The dissociation constant (K(D)) was 4.5 nm [95% confidence interval (CI) 3.6-5.4] for 12E-V2R-GFP and 16.5 nm (95% CI 10.1-22.9) for 12G-V2R-GFP. AVP-induced cAMP generation was......SUMMARY OBJECTIVES: Stimulation of arginine vasopressin 2 receptor (V2R) with arginine vasopressin (AVP) results in a rise in von Willebrand factor (VWF) and factor VIII plasma levels. We hypothesized that gain-of-function variations in the V2R gene (AVPR2) would lead to higher plasma levels of VWF...... levels. The functionality of the G12E variant was studied in stably transfected MDCKII cells, expressing constructs of either 12G-V2R or 12E-V2R. Both V2R variants were fully glycosylated and expressed on the basolateral membrane. The binding affinity of V2R for AVP was increased three-fold in 12E-V2R...

  20. Dietary arginine and N-carbamylglutamate supplementation enhances the antioxidant statuses of the liver and plasma against oxidative stress in rats.

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    Cao, Wei; Xiao, Liang; Liu, Guangmang; Fang, Tingting; Wu, Xianjian; Jia, Gang; Zhao, Hua; Chen, Xiaoling; Wu, Caimei; Cai, Jingyi; Wang, Jing

    2016-05-18

    N-Carbamylglutamate (NCG), an effective precursor of arginine (ARG), can enhance ARG synthesis, increase intestinal growth, and improve reproductive performance. However, the antioxidant effect of NCG remains largely unknown. This study aims to survey the effects of ARG and NCG supplementation on the antioxidant statuses of the liver and plasma in rats under oxidative stress. Rats were fed for 30 days with one of the three iso-nitrogenous diets: basal diet (BD), BD plus 1% ARG, and BD plus 0.1% NCG. On day 28, half of the rats fed with BD were intraperitoneally injected with 12 mg per kg body weight of diquat (diquat group) and the other half was injected intraperitoneally with sterile 0.9% NaCl solution (control group). The other diet groups also received an intraperitoneal injection of 12 mg per kg body weight of diquat, as follows: diquat + 1% ARG (DT + ARG), and diquat + 0.1% NCG (DT + NCG). Rat liver and plasma samples obtained 48 h after diquat injection were analyzed. Results indicated that diquat significantly affected the plasma conventional biochemical components (relative to the controls), which were partially alleviated in both the DT + ARG and DT + NCG groups (P AOC) in the liver and plasma (P AOC, enhanced plasma AHR activity, increased liver ASA activity, and decreased plasma MDA content (P < 0.05). Overall, supplementation of 1% ARG and 0.1% NCG can partially protect the liver and plasma from oxidative stress. Furthermore, compared with 1% ARG, 0.1% NCG more effectively alleviated oxidative stress. PMID:27109002

  1. Content of non-esterified fatty acids in the blood plasma of rabbits with acute arginine pancreatitis and its correction

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    Y. F. Rivis

    2013-01-01

    Full Text Available The aim of this work was to study the content of non-esterified fatty acids in plasma and liver of rabbits with acute arginine pancreatitis and its correction by linseed oil. The experiment was carried out on male rabbits breed gray giant with live weight 3.8–4.0 kg. The material for the study was sampled from blood and liver. Lipids from plasma and liver were extracted with a mixture of chloroform and methanol. After that the non-esterified fatty acids were isolated and methylated. Methyl esters of fatty acids were studied by the gas-liquid chromatography with the chromatograph ''Chrom 5'' (Prague,CzechRepublic. We have found that the content of non-esterified fatty acids decreases in the blood plasma and liver of rabbits with the acute arginine pancreatitis. It takes place at the expense of a reduce of saturated fatty acids with odd and even number of carbon atoms in a chain, monounsaturated fatty acids of the families ω-7 and ω-9 and polyunsaturated fatty acids of the families ω-3 and ω-6. That may indicate a greater use of non-esterified fatty acids for energy metabolism and esterification of lipids. We suppose that this is a consequence of the probable increase in content of non-esterified and esterified cholesterol in the rabbits’ blood plasma. Those processes provoke the cholesterol deposits in blood vessels and therefore cardiovascular diseases. We tried to influence on the processes by addition of linseed oil to the rabbits diet. We have found that in the linseed oil-fed rabbits the content of non-esterified fatty acids decreases at the expense of saturated fatty acids with odd and even number of carbon atoms in a chain and monounsaturated fatty acids of the families ω-7 and ω-9 inblood plasma and liver of the rabbits with acute arginine pancreatitis. Furthermore the levels of non-esterified polyunsaturated fatty acids of ω-3 family increase in the rabbits’ plasma and liver. As this takes place the ratio of non

  2. N-terminal arginines modulate plasma-membrane localization of Kv7.1/KCNE1 channel complexes.

    Directory of Open Access Journals (Sweden)

    Zenawit Girmatsion

    Full Text Available BACKGROUND AND OBJECTIVE: The slow delayed rectifier current (I(Ks is important for cardiac action potential termination. The underlying channel is composed of Kv7.1 α-subunits and KCNE1 β-subunits. While most evidence suggests a role of KCNE1 transmembrane domain and C-terminus for the interaction, the N-terminal KCNE1 polymorphism 38G is associated with reduced I(Ks and atrial fibrillation (a human arrhythmia. Structure-function relationship of the KCNE1 N-terminus for I(Ks modulation is poorly understood and was subject of this study. METHODS: We studied N-terminal KCNE1 constructs disrupting structurally important positively charged amino-acids (arginines at positions 32, 33, 36 as well as KCNE1 constructs that modify position 38 including an N-terminal truncation mutation. Experimental procedures included molecular cloning, patch-clamp recording, protein biochemistry, real-time-PCR and confocal microscopy. RESULTS: All KCNE1 constructs physically interacted with Kv7.1. I(Ks resulting from co-expression of Kv7.1 with non-atrial fibrillation '38S' was greater than with any other construct. Ionic currents resulting from co-transfection of a KCNE1 mutant with arginine substitutions ('38G-3xA' were comparable to currents evoked from cells transfected with an N-terminally truncated KCNE1-construct ('Δ1-38'. Western-blots from plasma-membrane preparations and confocal images consistently showed a greater amount of Kv7.1 protein at the plasma-membrane in cells co-transfected with the non-atrial fibrillation KCNE1-38S than with any other construct. CONCLUSIONS: The results of our study indicate that N-terminal arginines in positions 32, 33, 36 of KCNE1 are important for reconstitution of I(Ks. Furthermore, our results hint towards a role of these N-terminal amino-acids in membrane representation of the delayed rectifier channel complex.

  3. In ovo L-arginine supplementation stimulates myoblast differentiation but negatively affects muscle development of broiler chicken after hatching.

    Science.gov (United States)

    Li, Y; Wang, Y; Willems, E; Willemsen, H; Franssens, L; Buyse, J; Decuypere, E; Everaert, N

    2016-02-01

    In this study, we tested the hypothesis that in ovo feeding (IOF) of L-arginine (L-Arg) enhances nitric oxide (NO) production, stimulates the process of myogenesis, and regulates post-hatching muscle growth. Different doses of L-Arg were injected into the amnion of chicken embryos at embryonic day (ED) 16. After hatching, the body weight of individual male chickens was recorded weekly for 3 weeks. During in vitro experiments, myoblasts of the pectoralis major (PM) were extracted at ED16 and were incubated in medium containing 0.01 mm L-Arg, 0.05 mm L-Arg, and (or) 0.05 mm L-nitro-arginine-methyl-ester (L-NAME), an inhibitor of nitric oxide synthase (NOS). When 25 mg/kg L-Arg/initial egg weight was injected, no difference was observed in body weight at hatch, but a significant decrease was found during the following 3 weeks compared to that of the non-injected and saline-injected control, and this also affected the growth of muscle mass. L-NAME inhibited gene expression of myogenic differentiation antigen (MyoD), myogenin, NOS, and follistatin, decreased the cell viability, and increased myostatin (MSTN) gene expression. 0.05 mm L-Arg stimulated myogenin gene expression but also depressed muscle cell viability. L-NAME blocked the effect of 0.05 mm L-Arg on myogenin mRNA levels when co-incubated with 0.05 mm L-Arg. L-Arg treatments had no significant influence on NOS mRNA gene expression, but had inhibiting effect on follistatin gene expression, while L-NAME treatments had effects on both. These results suggested that L-Arg stimulated myoblast differentiation, but the limited number of myoblasts would form less myotubes and then less myofibers, while the latter limited the growth of muscle mass. PMID:25846259

  4. Effect of l-arginine therapy on plasma NO/sub 2/ and NO/sub 3/ levels, and blood pressure in uremic rabbits

    International Nuclear Information System (INIS)

    Background: Normal kidney function is regulated by Nitric oxide (NO) and Superoxide (O/sub 2/-) in the body, and consequently controls blood pressure. Nitric Oxide promotes natriuresis and diuresis, and therefore results in reduction of blood pressure. The objective of this study was to determine the effect of L-arginine supplementation on blood pressure, urinary protein, nitrite and nitrate in addition to blood urea, serum creatinine and creatinine clearance in uremic rabbits. Methods: This study was carried out in the Department of Biochemistry Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi. A total of 48 rabbits were included in the study. Twenty-four of the rabbits on surgical intervention were prepared as uremic and so became hypertensive as well. Two groups were uremic, one group was given L-arginine and the other was remained untreated. Systolic and diastolic blood pressure was measured on week 0, week 2, week 4, and week 6, while blood and urine was collected on week 0 and week 6. Results: On supplementation with L-arginine to uremic rabbits systolic and diastolic blood pressures were decreased significantly. Nitrite/nitrate and urinary protein were corrected to some extent while blood urea and serum creatinine were unaffected. Conclusion: L-arginine has a beneficial role as blood pressure lowering agent in uremic rabbits. It corrects NO/sub 2/NO/sub 3/ plasma level and proteinuria which is indicator of renal failure. (author)

  5. Characterization of conserved arginine residues on Cdt1 that affect licensing activity and interaction with Geminin or Mcm complex.

    Science.gov (United States)

    You, Zhiying; Ode, Koji L; Shindo, Mayumi; Takisawa, Haruhiko; Masai, Hisao

    2016-05-01

    All organisms ensure once and only once replication during S phase through a process called replication licensing. Cdt1 is a key component and crucial loading factor of Mcm complex, which is a central component for the eukaryotic replicative helicase. In higher eukaryotes, timely inhibition of Cdt1 by Geminin is essential to prevent rereplication. Here, we address the mechanism of DNA licensing using purified Cdt1, Mcm and Geminin proteins in combination with replication in Xenopus egg extracts. We mutagenized the 223th arginine of mouse Cdt1 (mCdt1) to cysteine or serine (R-S or R-C, respectively) and 342nd and 346th arginines constituting an arginine finger-like structure to alanine (RR-AA). The RR-AA mutant of Cdt1 could not only rescue the DNA replication activity in Cdt1-depleted extracts but also its specific activity for DNA replication and licensing was significantly increased compared to the wild-type protein. In contrast, the R223 mutants were partially defective in rescue of DNA replication and licensing. Biochemical analyses of these mutant Cdt1 proteins indicated that the RR-AA mutation disabled its functional interaction with Geminin, while R223 mutations resulted in ablation in interaction with the Mcm2∼7 complex. Intriguingly, the R223 mutants are more susceptible to the phosphorylation-induced inactivation or chromatin dissociation. Our results show that conserved arginine residues play critical roles in interaction with Geminin and Mcm that are crucial for proper conformation of the complexes and its licensing activity. PMID:26940553

  6. Arginine-Rich Peptides Destabilize the Plasma Membrane, Consistent with a Pore Formation Translocation Mechanism of Cell-Penetrating Peptides

    OpenAIRE

    Herce, H.D.; Garcia, A. E.; Litt, J.; Kane, R. S.; Martin, P.; Enrique, N.; Rebolledo, A.; Milesi, V.

    2009-01-01

    Recent molecular dynamics simulations (Herce and Garcia, PNAS, 104: 20805 (2007)) have suggested that the arginine-rich HIV Tat peptides might be able to translocate by destabilizing and inducing transient pores in phospholipid bilayers. In this pathway for peptide translocation, arginine residues play a fundamental role not only in the binding of the peptide to the surface of the membrane but also in the destabilization and nucleation of transient pores across the bilayer, despite being char...

  7. Arginine transport in catabolic disease states.

    Science.gov (United States)

    Pan, Ming; Choudry, Haroon A; Epler, Mark J; Meng, Qinghe; Karinch, Anne; Lin, Chengmao; Souba, Wiley

    2004-10-01

    Arginine appears to be a semiessential amino acid in humans during critical illness. Catabolic disease states such as sepsis, injury, and cancer cause an increase in arginine utilization, which exceeds body production, leading to arginine depletion. This is aggravated by the reduced nutrient intake that is associated with critical illness. Arginine depletion may have negative consequences on tissue function under these circumstances. Nutritional regimens containing arginine have been shown to improve nitrogen balance and lymphocyte function, and stimulate arginine transport in the liver. We have studied the effects of stress mediators on arginine transport in vascular endothelium, liver, and gut epithelium. In vascular endothelium, endotoxin stimulates arginine uptake, an effect that is mediated by the cytokine tumor necrosis factor-alpha (TNF-alpha) and by the cyclo-oxygenase pathway. This TNF-alpha stimulation involves the activation of intracellular protein kinase C (PKC). A significant increase in hepatic arginine transport activity also occurs following burn injury and in rats with progressive malignant disease. Surgical removal of the growing tumor results in a normalization of the accelerated hepatic arginine transport within days. Chronic metabolic acidosis and sepsis individually augment intestinal arginine transport in rats and Caco-2 cell culture. PKC and mitogen-activated protein kinases are involved in mediating the sepsis/acidosis stimulation of arginine transport. Understanding the regulation of plasma membrane arginine transport will enhance our knowledge of nutrition and metabolism in seriously ill patients and may lead to the design of improved nutritional support formulas. PMID:15465794

  8. Simultaneous stable-isotope dilution GC-MS measurement of homoarginine, guanidinoacetate and their common precursor arginine in plasma and their interrelationships in healthy and diseased humans.

    Science.gov (United States)

    Hanff, Erik; Kayacelebi, Arslan Arinc; Yanchev, Georgi Radoslavov; Maassen, Norbert; Haghikia, Arash; Tsikas, Dimitrios

    2016-03-01

    Low concentrations of L-homoarginine (hArg) in plasma or serum and urine have recently emerged as a novel cardiovascular risk factor. Previously, we reported gas chromatography-mass spectrometry (GC-MS) and GC-tandem MS (GC-MS/MS) methods for the quantitative determination of hArg and Arg in plasma, serum, urine and other biological samples. In these methods, plasma and serum are ultrafiltered by means of commercially available cartridges (10 kDa), and 10-µL ultrafiltrate aliquots are subjected to a two-step derivatization procedure, yielding the methyl ester tri(N-pentafluoropropionyl) derivatives. De novo prepared trideuteromethyl ester hArg (d3Me-hArg) was used as an internal standard. To make the hArg analysis in plasma more convenient, straightforward and cheaper we performed two key modifications: (1) precipitation of plasma proteins by methanol and (2) use of newly prepared and d3Me-hArg as the internal standard. The method was validated and used for the quantitative determination of hArg in human plasma by GC-MS after electron-capture negative-ion chemical ionization (ECNICI) using methane as the reactant gas. Intra-assay accuracy (recovery) and imprecision (relative standard deviation) were within generally accepted ranges (93-109 and 2.3-10 %, respectively). Furthermore, we extended the applicability of this method to guanidinoacetate (GAA). This is of particular importance because hArg and GAA are produced from Arg by the catalytic action of arginine:glycine amidinotransferase (AGAT) also known as glycine:arginine transamidinase (GATM). Using this method, we quantitated simultaneously hArg, Arg and GAA in the selected-ion monitoring mode in 10-µL aliquots of plasma. In plasma samples of 17 non-medicated healthy young men, the concentration of hArg, GAA and Arg was determined to be (mean ± SD) 1.7 ± 0.6, 2.6 ± 0.8, 91 ± 29 µM, respectively. The correlation between hArg and Arg was borderline (r = 0.47, P = 0.06). GAA strongly correlated with Arg (r

  9. Oral Administration of L-Arginine in Patients With Angina or Following Myocardial Infarction May Be Protective By Increasing Plasma Superoxide Dismutase and Total Thiols With Reduction in Serum Cholesterol and Xanthine Oxidase

    Directory of Open Access Journals (Sweden)

    Pratima Tripathi

    2009-01-01

    Full Text Available Administration of L-arginine has been shown to control ischemic injury by producing nitric oxide which dilates the vessels and thus maintains proper blood flow to the myocardium. In the present study attempt has been made to determine whether oral administration of L-arginine has any effect on oxidant/antioxidant homeostasis in ischemic myocardial patients [represented by the patients of acute angina (AA and acute myocardial infarction (MI]. L-arginine has antioxidant and antiapoptotic properties, decreases endothelin-1 expression and improves endothelial function, thereby controlling oxidative injury caused during myocardial ischemic syndrome. Effect of L-arginine administration on the status of free radical scavenging enzymes, pro-oxidant enzyme and antioxidants viz. total thiols, carbonyl content and plasma ascorbic acid levels in the patients has been evaluated. We have observed that L-arginine administration (three grams per day for 15 days resulted in increased activity of free radical scavenging enzyme superoxide dismutase (SOD and increase in the levels of total thiols (T-SH and ascorbic acid with concomitant decrease in lipid per-oxidation, carbonyl content, serum cholesterol and the activity of proxidant enzyme, xanthine oxidase (XO. These findings suggest that the supplementation of L-arginine along with regular therapy may be beneficial to the patients of ischemic myocardial syndromes.

  10. LC-QTOF-MS-based targeted metabolomics of arginine-creatine metabolic pathway-related compounds in plasma: application to identify potential biomarkers in pediatric chronic kidney disease.

    Science.gov (United States)

    Benito, Sandra; Sánchez, Alicia; Unceta, Nora; Andrade, Fernando; Aldámiz-Echevarria, Luis; Goicolea, M Aránzazu; Barrio, Ramón J

    2016-01-01

    Chronic kidney disease (CKD) is a major epidemiologic problem which causes several disturbances in adults and in pediatrics. Despite being a worldwide public health problem, information available for CKD in the pediatric population is scarce. For that reason, an ion-pair reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method has been developed and validated in order to analyze 16 amino acids, amino acid derivatives, and analogous compounds related to the arginine-creatine metabolic pathway that are suspicious of being increased or decreased in plasma from patients with CKD. The analytical method involved the addition of dithiothreitol, a reducing agent which reduces disulfide and thus giving total aminothiol concentration, as well as a simple precipitation of plasma proteins. Moreover, despite amino acids being usually derivatized to improve their retention time and to enhance their signal, for this method, an ion-pairing reagent was used, thus avoiding the need for derivatization. Subsequently, analysis of plasma from pediatric patients suffering from CKD and control pediatrics was carried out. As a result, glycine, citrulline, creatinine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) were significantly increased in patients with CKD, regardless of their creatinine level, whereas in addition to these compounds dimethylglycine was also increased when CKD patients had plasma creatinine concentrations above 12 μg mL(-1), thus all are suggested as potential biomarkers for renal impairment. PMID:26537926

  11. A co culture approach show that polyamine turnover is affected during inflammation in Atlantic salmon immune and liver cells and that arginine and LPS exerts opposite effects on p38MAPK signaling.

    Science.gov (United States)

    Holen, Elisabeth; Espe, Marit; Andersen, Synne M; Taylor, Richard; Aksnes, Anders; Mengesha, Zebasil; Araujo, Pedro

    2014-04-01

    This study assess which pathways and molecular processes are affected by exposing salmon head kidney cells or liver cells to arginine supplementation above the established requirements for growth support. In addition to the conventional mono cultures of liver and head kidney cells, co cultures of the two cell types were included in the experimental set up. Responses due to elevated levels of arginine were measured during inflammatory (lipopolysaccharide/LPS) and non -inflammatory conditions. LPS up regulated the genes involved in polyamine turnover; ODC (ornithine decarboxylase), SSAT (spermidine/spermine-N1-acetyltransferase) and SAMdc (S-adenosyl methionine decarboxylase) in head kidney cells when co cultured with liver cells. Regardless of treatment, liver cells in co culture up regulated ODC and down regulated SSAT when compared to liver mono cultures. This suggests that polyamines have anti-inflammatory properties and that both salmon liver cells and immune cells seem to be involved in this process. The transcription of C/EBP β/CCAAT, increased during inflammation in all cultures except for liver mono cultures. The observed up regulation of this gene may be linked to glucose transport due to the highly variable glucose concentrations found in the cell media. PPARα transcription was also increased in liver cells when receiving signals from head kidney cells. Gene transcription of Interleukin 1β (IL-1β), Interleukin-8 (IL-8), cyclooxygenase 2 (COX2) and CD83 were elevated during LPS treatment in all the head kidney cell cultures while arginine supplementation reduced IL-1β and IL-8 transcription in liver cells co cultured with head kidney cells. This is probably connected to p38MAPK signaling as arginine seem to affect p38MAPK signaling contrary to the LPS induced p38MAPK signaling, suggesting anti-inflammatory effects of arginine/arginine metabolites. This paper shows that co culturing these two cell types reveals the connection between metabolism and

  12. Blood sampling and hemolysis affect concentration of plasma metabolites

    DEFF Research Database (Denmark)

    Theil, Peter Kappel; Pedersen, Lene Juul; Jensen, Margit Bak;

    2012-01-01

    Two experiments were carried out to reveal and quantify plasma metabolites that are sensitive to hemolysis and animal stress due to the blood sampling procedure (vein puncture vs. catheter). In Exp. 1, 48 sows were fed 4 diets either once (0800 h) or twice daily (0800 h and 1500 h) in a crossover...... design and blood was collected after restraint via vein puncture 1, 4, 11, and 23 h after morning feeding. Plasma samples were categorized as without or with minor or major hemolysis [clear (n = 218), yellow (n = 97), or red (n = 37)] upon centrifugation. Plasma NEFA (P < 0.001) was lower in hemolyzed...... samples but plasma propionate, caproate, isovalerate (P < 0.001), and isobutyrate (P < 0.05) were higher in hemolyzed samples. Plasma glucose and lactate were the only metabolites that were not affected by hemolysis. Interactions with hemolysis and other fixed effects were not found (P > 0.05). In Exp. 2...

  13. Top-dressing 1% arginine supplementation in the lactation diet of sows does not affect the litter performance and milk composition

    OpenAIRE

    Djane Dallanora; Marina Patricia Walter; Jéssica Marcon; Camila Saremba; Mari Lourdes Bernardi; Ivo Wentz; Fernando Pandolfo Bortolozzo

    2016-01-01

    ABSTRACT: The study aimed to evaluate the effects of arginine supplementation in the lactation diet of sows on their milk composition, litter performance and piglet survival. Sixty-four lactating Landrace x Large White sows, parity 1 to 7, were randomly assigned to two treatments: 1) Control - a corn/soybean meal based diet with 1.10% standardized ileal digestible (SID) lysine and 3,475kcal of metabolizable energy (ME) kg-1, and 2) arginine - the control diet top-dressed daily with arginine a...

  14. Arginine-rich peptides destabilize the plasma membrane, consistent with a pore formation translocation mechanism of cell-penetrating peptides.

    Science.gov (United States)

    Herce, H D; Garcia, A E; Litt, J; Kane, R S; Martin, P; Enrique, N; Rebolledo, A; Milesi, V

    2009-10-01

    Recent molecular-dynamics simulations have suggested that the arginine-rich HIV Tat peptides translocate by destabilizing and inducing transient pores in phospholipid bilayers. In this pathway for peptide translocation, Arg residues play a fundamental role not only in the binding of the peptide to the surface of the membrane, but also in the destabilization and nucleation of transient pores across the bilayer. Here we present a molecular-dynamics simulation of a peptide composed of nine Args (Arg-9) that shows that this peptide follows the same translocation pathway previously found for the Tat peptide. We test experimentally the hypothesis that transient pores open by measuring ionic currents across phospholipid bilayers and cell membranes through the pores induced by Arg-9 peptides. We find that Arg-9 peptides, in the presence of an electrostatic potential gradient, induce ionic currents across planar phospholipid bilayers, as well as in cultured osteosarcoma cells and human smooth muscle cells. Our results suggest that the mechanism of action of Arg-9 peptides involves the creation of transient pores in lipid bilayers and cell membranes. PMID:19804722

  15. Direct characterization of factor VIII in plasma: detection of a mutation altering a thrombin cleavage site (arginine-372----histidine).

    OpenAIRE

    Arai, M.; Inaba, H; Higuchi, M; Antonarakis, S E; Kazazian, H H; Fujimaki, M.; Hoyer, L W

    1989-01-01

    An immunoadsorbent method has been developed for the direct analysis of normal and variant plasma factor VIII. Using this method, the molecular defect responsible for mild hemophilia A has been identified for a patient whose plasma factor VIII activity is 0.05 unit/ml, even though the factor VIII antigen content is 3.25 units/ml. Although the variant factor VIII has an apparently normal molecular mass and chain composition, the 92-kDa heavy chain accumulates when the variant protein is incuba...

  16. Anticoagulants used in plasma collection affect adipokine multiplexed measurements.

    Science.gov (United States)

    Allione, Alessandra; Di Gaetano, Cornelia; Dani, Nadia; Barberio, Davide; Sieri, Sabina; Krogh, Vittorio; Matullo, Giuseppe

    2016-04-01

    Obesity is an important health problem worldwide. Adipose tissue acts as an endocrine organ that secretes various bioactive substances, called adipokines, including pro-inflammatory biomarkers such as TNF-α, IL-6, leptin and C-reactive protein (CRP) and anti-inflammatory molecules such as adiponectin. The deregulated production of adipokines in obesity is linked to the pathogenesis of various disease processes and monitoring their variation is critical to understand metabolic diseases. The aim of this study was to determine the plasma concentration of adipokines in healthy subjects by multiplexed measurements and the effect of anticoagulants on their levels. Plasma samples from 10 healthy donors were collected in two different anticoagulants (sodium citrate or heparin). All markers, excluding TNF-α, showed significantly higher concentrations in heparinized compared to citrate plasma. However, levels of adipokines in different plasma samples were highly correlated for most of these markers. We reported that different anticoagulants used in the preparation of the plasma samples affected the measurements of some adipokines. The importance of the present results in epidemiology is relevant when comparing different studies in which blood samples were collected with different anticoagulants. PMID:26945995

  17. Rapid formation of plasma protein corona critically affects nanoparticle pathophysiology

    Science.gov (United States)

    Tenzer, Stefan; Docter, Dominic; Kuharev, Jörg; Musyanovych, Anna; Fetz, Verena; Hecht, Rouven; Schlenk, Florian; Fischer, Dagmar; Kiouptsi, Klytaimnistra; Reinhardt, Christoph; Landfester, Katharina; Schild, Hansjörg; Maskos, Michael; Knauer, Shirley K.; Stauber, Roland H.

    2013-10-01

    In biological fluids, proteins bind to the surface of nanoparticles to form a coating known as the protein corona, which can critically affect the interaction of the nanoparticles with living systems. As physiological systems are highly dynamic, it is important to obtain a time-resolved knowledge of protein-corona formation, development and biological relevancy. Here we show that label-free snapshot proteomics can be used to obtain quantitative time-resolved profiles of human plasma coronas formed on silica and polystyrene nanoparticles of various size and surface functionalization. Complex time- and nanoparticle-specific coronas, which comprise almost 300 different proteins, were found to form rapidly (<0.5 minutes) and, over time, to change significantly in terms of the amount of bound protein, but not in composition. Rapid corona formation is found to affect haemolysis, thrombocyte activation, nanoparticle uptake and endothelial cell death at an early exposure time.

  18. Arginine regulation of gramicidin S biosynthesis.

    OpenAIRE

    Poirier, A.; Demain, A L

    1981-01-01

    Several amino acids are known to affect the gramicidin S producer Bacillus brevis ATCC 9999 with respect ot growth, soluble gramicidin S synthetase formation, antibiotic production, or a combination of these. Our studies confirmed that arginine has paradoxical effects on the B. brevis fermentation; it markedly increased growth and antibiotic production, yet decreased the soluble heavy gramicidin S synthetase activity. We found that arginine did not repress heavy gramicidin S synthetase. The a...

  19. An Onion Byproduct Affects Plasma Lipids in Healthy Rats

    DEFF Research Database (Denmark)

    Roldan-Marin, E.; Jensen, R. I.; Krath, Britta;

    2010-01-01

    that the controls could be completely separated from OBP, OE, and OR groups in the scores plot and also that OE and OR groups were separated. Plasma lipids and bile acid excretion were the discriminating loading factors for separating OE and OR but also contributed to the separation of onion......Onion may contribute to the health effects associated with high fruit and vegetable consumption. A considerable amount of onion production ends up as waste that might find use in foods. Onion byproduct has not yet been explored for potential health benefits. The aim of this study is to elucidate...... the safety and potential role of onion byproducts in affecting risk markers of cardiovascular disease (CVD). For that purpose, the effects of an onion byproduct, Allium cepa L. cepa 'Recas' (OBP), and its two derived fractions, an ethanolic extract (OE) and a residue (OR), on the distribution of...

  20. L-Arginine Affects Aerobic Capacity and Muscle Metabolism in MELAS (Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-Like Episodes Syndrome.

    Directory of Open Access Journals (Sweden)

    Lance H Rodan

    Full Text Available To study the effects of L-arginine (L-Arg on total body aerobic capacity and muscle metabolism as assessed by (31Phosphorus Magnetic Resonance Spectroscopy ((31P-MRS in patients with MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes syndrome.We performed a case control study in 3 MELAS siblings (m.3243A>G tRNA(leu(UUR in MTTL1 gene with different % blood mutant mtDNA to evaluate total body maximal aerobic capacity (VO(2peak using graded cycle ergometry and muscle metabolism using 31P-MRS. We then ran a clinical trial pilot study in MELAS sibs to assess response of these parameters to single dose and a 6-week steady-state trial of oral L-Arginine.At baseline (no L-Arg, MELAS had lower serum Arg (p = 0.001. On 3(1P-MRS muscle at rest, MELAS subjects had increased phosphocreatine (PCr (p = 0.05, decreased ATP (p = 0.018, and decreased intracellular Mg(2+ (p = 0.0002 when compared to matched controls. With L-arginine therapy, the following trends were noted in MELAS siblings on cycle ergometry: (1 increase in mean % maximum work at anaerobic threshold (AT (2 increase in % maximum heart rate at AT (3 small increase in VO(2peak. On (31P-MRS the following mean trends were noted: (1 A blunted decrease in pH after exercise (less acidosis (2 increase in Pi/PCr ratio (ADP suggesting increased work capacity (3 a faster half time of PCr recovery (marker of mitochondrial activity following 5 minutes of moderate intensity exercise (4 increase in torque.These results suggest an improvement in aerobic capacity and muscle metabolism in MELAS subjects in response to supplementation with L-Arg. Intramyocellular hypomagnesemia is a novel finding that warrants further study.Class III evidence that L-arginine improves aerobic capacity and muscle metabolism in MELAS subjects.ClinicalTrials.gov NCT01603446.

  1. A novel mutation affecting the arginine-137 residue of AVPR2 in dizygous twins leads to nephrogenic diabetes insipidus and attenuated urine exosome aquaporin-2

    DEFF Research Database (Denmark)

    Hinrichs, Gitte R; Hansen, Louise H; Nielsen, Maria R;

    2016-01-01

    Mutations in the vasopressin V2 receptor gene AVPR2 may cause X-linked nephrogenic diabetes insipidus by defective apical insertion of aquaporin-2 in the renal collecting duct principal cell. Substitution mutations with exchange of arginine at codon 137 can cause nephrogenic syndrome of inappropr...... administration. While a similar urine exosome release rate was shown between probands and controls by western blotting for the marker ALIX, there was a selective decrease in exosome aquaporin-2 versus aquaporin-1 protein in probands compared to controls....

  2. In vivo arginine production and intravascular nitric oxide synthesis in hypotensive sepsis

    Science.gov (United States)

    Arginine is important in the response to infections and is a precursor for the synthesis of the vasodilator nitric oxide (NO). Low plasma arginine is correlated with a worse prognosis in patients with sepsis, and increased NO has been implicated in the hypotension of sepsis. Data on in vivo arginine...

  3. Transcutaneous Electrical Acupoint Stimulation in Children with Autism and Its Impact on Plasma Levels of Arginine-Vasopressin and Oxytocin: A Prospective Single-Blinded Controlled Study

    Science.gov (United States)

    Zhang, Rong; Jia, Mei-Xiang; Zhang, Ji-Sui; Xu, Xin-Jie; Shou, Xiao-Jing; Zhang, Xiu-Ting; Li, Li; Li, Ning; Han, Song-Ping; Han, Ji-Sheng

    2012-01-01

    Acupuncture increases brain levels of arginine-vasopressin (AVP) and oxytocin (OXT), which are known to be involved in the modulation of mammalian social behavior. Transcutaneous electrical acupoint stimulation (TEAS) is often used clinically to produce a similar stimulation to that of acupuncture on the acupoints. In the present study, TEAS was…

  4. L-arginine

    Science.gov (United States)

    ... your health provider.Medications for high blood pressure (ACE inhibitors)L-arginine seems to decrease blood pressure. Taking ... with certain medications for high blood pressure, called ACE inhibitors might cause your blood pressure to go too ...

  5. Arginine, citrulline and nitric oxide metabolism in sepsis

    Science.gov (United States)

    Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

  6. How various plasma sources may affect seed germination and growth

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena; Gajdová, Iveta; Čermák, M.; Gavril, B.; Hnatiuc, E.; Kováčik, D.; Kříha, V.; Sláma, J.; Šerý, M.; Špatenka, P.

    Brasov : Universitatea Transilvania din Brasov, 2012 - (Clotea, L.; Cernat, M.). s. 250-250 ISBN 978-1-4673-1650-7. [International Conference on Optimization of Electrical and Electronic Equipment /13./ OPTIM 2012. 24.05.-26.05.2012, Brasov] Institutional research plan: CEZ:AV0Z60870520 Keywords : seed germination * bio- plasma * nonthermal plasma * biotechnology Subject RIV: EI - Biotechnology ; Bionics

  7. Arginine and nitrogen storage.

    Science.gov (United States)

    Llácer, José L; Fita, Ignacio; Rubio, Vicente

    2008-12-01

    When nitrogen is abundant, prokaryotic and eukaryotic oxygen-producing photosynthetic organisms store nitrogen as arginine, by relieving feedback inhibition of the arginine biosynthesis controlling enzyme, N-acetylglutamate kinase (NAGK). The signalling protein PII, an ancient and widely distributed nitrogen/carbon/ADP/ATP sensor, mediates feedback inhibition relief of NAGK by binding to this enzyme. PII phosphorylation or PII binding of ADP or 2-oxoglutarate prevents PII-NAGK complex formation. Crystal structures of NAGK, cyanobacterial and plant PII and corresponding PII-NAGK complexes have been recently determined. In these complexes, two polar PII trimers sandwich one ring-like NAGK hexamer. Each PII subunit contacts one NAGK subunit, triggering a symmetry-restricted narrowing of the NAGK ring, with concomitant adoption by the arginine sites of a low-affinity conformation. PMID:19013524

  8. Arginine metabolism in wounds

    International Nuclear Information System (INIS)

    Arginine metabolism in wounds was investigated in the rat in 1) lambda-carrageenan-wounded skeletal muscle, 2) Schilling chambers, and 3) subcutaneous polyvinyl alcohol sponges. All showed decreased arginine and elevated ornithine contents and high arginase activity. Arginase could be brought to the wound by macrophages, which were found to contain arginase activity. However, arginase was expressed by macrophages only after cell lysis and no arginase was released by viable macrophages in vitro. Thus the extracellular arginase of wounds may derive from dead macrophages within the injured tissue. Wound and peritoneal macrophages exhibited arginase deiminase activity as demonstrated by the conversion of [guanido-14C]arginine to radiolabeled citrulline during culture, the inhibition of this reaction by formamidinium acetate, and the lack of prokaryotic contamination of the cultures. These findings and the known metabolic fates of the products of arginase and arginine deiminase in the cellular populations of the wound suggest the possibility of cooperativity among cells for the production of substrates for collagen synthesis

  9. L-arginine

    Science.gov (United States)

    ... pain (angina pectoris). Leg pain associated with poor blood flow (peripheral arterial disease). Research suggests that taking L-arginine by mouth ... by IV) for up to 8 weeks increases blood flow in people with peripheral arterial disease. However, long-term use (up to 6 months) ...

  10. How various plasma sources may affect seed gemination and growth

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena; Gajdová, Iveta; Čermák, M.; Gavril, B.; Hnatiuc, E.; Kováčik, D.; Kříha, V.; Sláma, J.; Šerý, M.; Špatenka, P.

    Brasov: Universitatea Transilvania din Brasov, 2012 - (Clotea, L.; Cernat, M.), s. 1365-1370 ISBN 978-1-4673-1650-7. [Optimization of Electrical and Electronic Equipment (OPTIM), 2012 13th International Conference. Brasov (RO), 24.05.2012-26.05.2012] Institutional support: RVO:67179843 Keywords : non thermal plasma * atmospheric pressure * biotechnology * systems biology * seed germination * early growth Subject RIV: EI - Biotechnology ; Bionics

  11. The Ergogenic Potential of Arginine

    Directory of Open Access Journals (Sweden)

    La Bounty Paul M

    2004-12-01

    Full Text Available Abstract Arginine is a conditionally essential amino acid that is involved in protein synthesis, the detoxification of ammonia, and its conversion to glucose as well as being catabolized to produce energy. In addition to these physiological functions, arginine has been purported to have ergogenic potential. Athletes have taken arginine for three main reasons: 1 its role in the secretion of endogenous growth hormone; 2 its involvement in the synthesis of creatine; 3 its role in augmenting nitric oxide. These aspects of arginine supplementation will be discussed as well as a review of clinical investigations involving exercise performance and arginine ingestion.

  12. The Arginine/ADMA Ratio Is Related to the Prevention of Atherosclerotic Plaques in Hypercholesterolemic Rabbits When Giving a Combined Therapy with Atorvastatine and Arginine

    Directory of Open Access Journals (Sweden)

    Saskia J. H. Brinkmann

    2015-05-01

    Full Text Available Supplementation with arginine in combination with atorvastatin is more efficient in reducing the size of an atherosclerotic plaque than treatment with a statin or arginine alone in homozygous Watanabe heritable hyperlipidemic (WHHL rabbits. We evaluated the mechanism behind this feature by exploring the role of the arginine/asymmetric dimethylarginine (ADMA ratio, which is the substrate and inhibitor of nitric oxide synthase (NOS and thereby nitric oxide (NO, respectively. Methods: Rabbits were fed either an arginine diet (group A, n = 9, standard rabbit chow plus atorvastatin (group S, n = 8, standard rabbit chow plus an arginine diet with atorvastatin (group SA, n = 8 or standard rabbit chow (group C, n = 9 as control. Blood was sampled and the aorta was harvested for topographic and histological analysis. Plasma levels of arginine, ADMA, cholesterol and nitric oxide were determined and the arginine/ADMA ratio was calculated. Results: The decrease in ADMA levels over time was significantly correlated to fewer aortic lesions in the distal aorta and total aorta. The arginine/ADMA ratio was correlated to cholesterol levels and decrease in cholesterol levels over time in the SA group. A lower arginine/ADMA ratio was significantly correlated to lower NO levels in the S and C group. Discussion: A balance between arginine and ADMA is an important indicator in the prevention of the development of atherosclerotic plaques.

  13. Arginine methylation regulates the p53 response

    DEFF Research Database (Denmark)

    Jansson, Martin; Durant, Stephen T; Cho, Er-Chieh;

    2008-01-01

    Activation of the p53 tumour suppressor protein in response to DNA damage leads to apoptosis or cell-cycle arrest. Enzymatic modifications are widely believed to affect and regulate p53 activity. We describe here a level of post-translational control that has an important functional consequence on...... of p53. Furthermore, PRMT5 depletion triggers p53-dependent apoptosis. Thus, methylation on arginine residues is an underlying mechanism of control during the p53 response....

  14. Dietary arginine and linear growth

    DEFF Research Database (Denmark)

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W;

    2013-01-01

    The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School...

  15. Factors which affect operation of a plasma focus in various gases

    International Nuclear Information System (INIS)

    It is shown that the axial transit time ta and the ratio of specific heats are the main factors which affect the operation of a plasma focus in various gases. An energy balance theory is used to explore this dependence. The results are consistent with previous calculations and with experiments. (author)

  16. Oral L-arginine supplementation impacts several reproductive parameters during the postpartum period in mares.

    Science.gov (United States)

    Kelley, Dale E; Warren, Lori K; Mortensen, Christopher J

    2013-05-01

    L-arginine is an amino acid which can alter pituitary function and increase blood flow to the reproductive tract. The objective was to determine the effect of supplementing 100g of L-arginine on plasma arginine concentrations, follicular dynamics and ovarian and uterine artery blood flow during the estrus that occurs subsequent to foaling. In Experiment 1, mares were fed 100g L-arginine for 1 day during the last 3 weeks of pregnancy and plasma samples taken for every hour for the first 4h and every other hour until 12h.L-arginine supplementation elevated plasma arginine concentrations from 1 to 8h post feeding; arginine peaked at 6h (arginine: 515±33μmol/L; control: 80±33μmol/L). In Experiment 2, mares received either 100g L-arginine or control diets beginning 21 d before the expected foaling date and continued for 30 d postpartum. The reproductive tract was evaluated by transrectal Doppler ultrasonography from Day 1 postpartum through Day 30. There were no differences in ovarian follicular dynamics, ovarian or uterine resistance indices between groups. Vascular perfusion of the F1 follicular wall was greater in L-arginine supplemented mares (37.3±2.6%) than controls (25.4±2.7%; Pmares had a smaller uterine body and horns and accumulated less uterine fluid than controls (Pfollicular development, raises the possible use of L-arginine supplementation as a breeding management tool during the postpartum period to increase reproductive success. PMID:23523236

  17. Studies on Factors Affecting Plasma PIVKA-II Levels in Hepatocellular Carcinoma

    OpenAIRE

    Soga, Kenji; Arai, Futoshi; Tsuruya, Takashi; Aikawa, Keiko; Toshima, Muneatsu; Shibasaki, Koichi; Aoyagi, Yutaka

    1993-01-01

    In order to diagnose hepatocellular carcinoma (HCC), plasma levels of protein induced by vitamin K absence or antagonist-II (PIVKA-II) were determined by an enzyme-linked immunosorbent assay (ELISA). Positive reaction was noted in 34 (68%) of 50 patients with HCC, with PIVKA-II serving as an useful tumor marker in the estimation of HCC staging. On the other hand, the administration of vitamin K and the presence of jaundice were found to be important factors that affect plasma PIVKA-II levels....

  18. L-Arginine Supplementation and Metabolism in Asthma

    Directory of Open Access Journals (Sweden)

    Angela Linderholm

    2011-01-01

    Full Text Available L-Arginine, the amino acid substrate for nitric oxide synthase, has been tested as a therapeutic intervention in a variety of chronic diseases and is commonly used as a nutritional supplement. In this study, we hypothesized that a subset of moderate to severe persistent asthma patients would benefit from supplementation with L-arginine by transiently increasing nitric oxide levels, resulting in bronchodilation and a reduction in inflammation. The pilot study consisted of a 3 month randomized, double-blind, placebo-controlled trial of L-arginine (0.05 g/kg twice daily in patients with moderate to severe asthma. We measured spirometry, exhaled breath nitric oxide, serum arginine metabolites, questionnaire scores, daily medication use and PEFR with the primary endpoint being the number of minor exacerbations at three months. Interim analysis of the 20 subjects showed no difference in the number of exacerbations, exhaled nitric oxide levels or lung function between groups, though participants in the L-arginine group had higher serum L-arginine at day 60 (2.0 ± 0.6 × 10−3 vs. 1.1 ± 0.2 × 10−3 µmol/L, p < 0.05, ornithine at day 30 (2.4 ± 0.9 vs. 1.2 ± 0.3 µmol/L serum, p < 0.05 and ADMA at day 30 (6.0 ± 1.5 × 10−1 vs. 2.6 ± 0.6 × 10−1 µmol/L serum, p < 0.05 on average compared to the placebo group. The study was terminated prematurely. Supplementing asthma subjects with L-arginine increases plasma levels; whether subgroups might benefit from such supplementation requires further study.

  19. Short Hypoxia Does not Affect Plasma Leptin in Healthy Men under Euglycemic Clamp Conditions

    Directory of Open Access Journals (Sweden)

    Andre Schmoller

    2009-01-01

    Full Text Available Leptin is involved in the endocrine control of energy expenditure and body weight regulation. Previous studies emphasize a relationship between hypoxic states and leptin concentrations. The aim of this study was to investigate the effects of acute hypoxia on leptin concentrations in healthy subjects. We examined 14 healthy men. Hypoxic conditions were induced by decreasing oxygen saturation to 75% for 30 minutes. Plasma leptin concentrations were determined at baseline, after 3 hours of euglycemic clamping, during hypoxia, and repeatedly the following 2.5 hours thereafter. Our results show an increase of plasma leptin concentrations in the course of 6 hours of hyperinsulinemic-euglycemic clamping which may reflect diurnal rhythmicity. Notwithstanding, there was no difference between levels of leptin in the hypoxic and the normoxic condition (=.2. Since we did not find any significant changes in leptin responses upon hypoxia, plasma leptin levels do not seem to be affected by short hypoxic episodes of moderate degree.

  20. Therapeutic control of plasma concentrations and long-term effect of nortriptyline in recurrent affective disorders.

    Science.gov (United States)

    Kragh-Sørensen; Hansen, C E; Baastrup, P C; Hvidberg, E F

    1976-07-01

    Based on the evidence that therapeutic plasma concentration range in fact exists for the tricyclic antidepressant drug, Nortriptyline (range 50-150 ng/ml), three different investigations were under taken in order to clarify some clinical pharmacological problems during long-term treatment with this drug. The possible prophlactic effect of the drug in recurrent affective disorders was specially examined in a group of patients with a high risk of episodes in their unipolar manic-depressive disease. The results highly demonstrate the value of monitoring plasma levels in achieving therapeutic control. Depressive relapses during treatment, for months and years, were only related to therapeutic insufficient plasma levels of the drug. PMID:981330

  1. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice

    DEFF Research Database (Denmark)

    Chennupati, Ramesh; Meens, Merlijn J P M T; Marion, Vincent;

    2014-01-01

    : Absence of endothelial citrulline recycling to arginine did not affect blood pressure and systemic arterial vasomotor responses in healthy mice. EDNO-mediated vasodilatation was significantly more impaired in diabetic Ass-KOTie2 than in control mice demonstrating that endothelial arginine recycling...

  2. Arginine becomes an essential amino acid after massive resection of rat small intestine.

    Science.gov (United States)

    Wakabayashi, Y; Yamada, E; Yoshida, T; Takahashi, H

    1994-12-23

    We compared effects of feeding arginine- and/or proline- deficient diets (-Arg, -Pro, and -Arg, Pro) with those of a complete diet (Complete) in rats whose small intestine had been massively resected. After 4 weeks, the rats fed -Arg and -Arg, Pro lost weight (a mean of 28 and 32 g, respectively), whereas those fed Complete and -Pro gained 80 and 58 g, respectively. The average nitrogen balance was about 117,100, -20 and -14 mg/day for Complete, -Pro, -Arg, and -Arg, Pro diets, respectively. The concentration of arginine in skeletal muscle was about 310, 330, 91, and 65 nmol/g for Complete, -Pro, -Arg, and -Arg, Pro, respectively; while plasma arginine concentration averaged 95, 107, 56, and 46 microM, respectively. The weight loss, the negative nitrogen balance, and the markedly reduced arginine concentration in the muscle observed in rats fed -Arg and -Arg, Pro clearly indicate that arginine becomes a strictly essential amino acid in the rats with massive resection of the small intestine. However, sufficient proline can be synthesized from arginine in tissues such as the liver and kidney in the absence of the small intestine. Plasma glutamine, citrulline in the muscle and plasma, urinary excretion of orotic acid and nitrate (to assess nitric oxide formation from arginine) were also measured, and the changes in these metabolites are discussed. PMID:7798273

  3. Basis of Arginine Sensitivity of Microbial N-Acetyl-l-Glutamate Kinases: Mutagenesis and Protein Engineering Study with the Pseudomonas aeruginosa and Escherichia coli Enzymes▿

    Science.gov (United States)

    Fernández-Murga, M. Leonor; Rubio, Vicente

    2008-01-01

    N-Acetylglutamate kinase (NAGK) catalyzes the second step of arginine biosynthesis. In Pseudomonas aeruginosa, but not in Escherichia coli, this step is rate limiting and feedback and sigmoidally inhibited by arginine. Crystal structures revealed that arginine-insensitive E. coli NAGK (EcNAGK) is homodimeric, whereas arginine-inhibitable NAGKs, including P. aeruginosa NAGK (PaNAGK), are hexamers in which an extra N-terminal kinked helix (N-helix) interlinks three dimers. By introducing single amino acid replacements in PaNAGK, we prove the functionality of the structurally identified arginine site, as arginine site mutations selectively decreased the apparent affinity for arginine. N-helix mutations affecting R24 and E17 increased and decreased, respectively, the apparent affinity of PaNAGK for arginine, as predicted from enzyme structures that revealed the respective formation by these residues of bonds favoring inaccessible and accessible arginine site conformations. N-helix N-terminal deletions spanning ≥16 residues dissociated PaNAGK to active dimers, those of ≤20 residues decreased the apparent affinity for arginine, and complete N-helix deletion (26 residues) abolished arginine inhibition. Upon attachment of the PaNAGK N-terminal extension to the EcNAGK N terminus, EcNAGK remained dimeric and arginine insensitive. We concluded that the N-helix and its C-terminal portion after the kink are essential but not sufficient for hexamer formation and arginine inhibition, respectively; that the N-helix modulates NAGK affinity for arginine and mediates signal transmission between arginine sites, thus establishing sigmoidal arginine inhibition kinetics; that the mobile αH-β16 loop of the arginine site is the modulatory signal receiver; and that the hexameric architecture is not essential for arginine inhibition but is functionally essential for physiologically relevant arginine control of NAGK. PMID:18263723

  4. Basis of arginine sensitivity of microbial N-acetyl-L-glutamate kinases: mutagenesis and protein engineering study with the Pseudomonas aeruginosa and Escherichia coli enzymes.

    Science.gov (United States)

    Fernández-Murga, M Leonor; Rubio, Vicente

    2008-04-01

    N-acetylglutamate kinase (NAGK) catalyzes the second step of arginine biosynthesis. In Pseudomonas aeruginosa, but not in Escherichia coli, this step is rate limiting and feedback and sigmoidally inhibited by arginine. Crystal structures revealed that arginine-insensitive E. coli NAGK (EcNAGK) is homodimeric, whereas arginine-inhibitable NAGKs, including P. aeruginosa NAGK (PaNAGK), are hexamers in which an extra N-terminal kinked helix (N-helix) interlinks three dimers. By introducing single amino acid replacements in PaNAGK, we prove the functionality of the structurally identified arginine site, as arginine site mutations selectively decreased the apparent affinity for arginine. N-helix mutations affecting R24 and E17 increased and decreased, respectively, the apparent affinity of PaNAGK for arginine, as predicted from enzyme structures that revealed the respective formation by these residues of bonds favoring inaccessible and accessible arginine site conformations. N-helix N-terminal deletions spanning > or = 16 residues dissociated PaNAGK to active dimers, those of arginine, and complete N-helix deletion (26 residues) abolished arginine inhibition. Upon attachment of the PaNAGK N-terminal extension to the EcNAGK N terminus, EcNAGK remained dimeric and arginine insensitive. We concluded that the N-helix and its C-terminal portion after the kink are essential but not sufficient for hexamer formation and arginine inhibition, respectively; that the N-helix modulates NAGK affinity for arginine and mediates signal transmission between arginine sites, thus establishing sigmoidal arginine inhibition kinetics; that the mobile alphaH-beta16 loop of the arginine site is the modulatory signal receiver; and that the hexameric architecture is not essential for arginine inhibition but is functionally essential for physiologically relevant arginine control of NAGK. PMID:18263723

  5. Inhibition of lytic infection of pseudorabies virus by arginine depletion

    International Nuclear Information System (INIS)

    Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzing the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression

  6. The subcellular compartmentalization of arginine metabolizing enzymes and their role in endothelial dysfunction

    Directory of Open Access Journals (Sweden)

    Feng eChen

    2013-07-01

    Full Text Available The endothelial production of nitric oxide (NO mediates endothelium-dependent vasorelaxation and restrains vascular inflammation, smooth muscle proliferation and platelet aggregation. Impaired production of NO is a hallmark of endothelial dysfunction and promotes the development of cardiovascular disease. In endothelial cells, NO is generated by endothelial nitric oxide synthase (eNOS through the conversion of its substrate, L-arginine to L-citrulline. Reduced access to L-arginine has been proposed as a major mechanism underlying reduced eNOS activity and NO production in cardiovascular disease. The arginases (Arg1 and Arg2 metabolize L-arginine to generate L-ornithine and urea and increased expression of arginase has been proposed as a mechanism of reduced eNOS activity secondary to the depletion of L-arginine. Indeed, supplemental L-arginine and suppression of arginase activity has been shown to improve endothelium-dependent relaxation and ameliorate cardiovascular disease. However, L-arginine concentrations in endothelial cells remain sufficiently high to support NO synthesis suggesting additional mechanisms. The compartmentalization of intracellular L-arginine into poorly interchangeable pools has been proposed to allow for the local depletion of L-arginine. Indeed the subcellular location of L-arginine metabolizing enzymes plays important functional roles. In endothelial cells, eNOS is found in discrete intracellular locations and the capacity to generate NO is heavily influenced by its localtion. Arg1 and Arg2 also reside in different subcellular environments and are thought to differentially influence endothelial function. The plasma membrane solute transporter, CAT-1 and the arginine recycling enzyme, ASL, co-localize with eNOS and facilitate NO release. This review highlights the importance of the subcellular location of eNOS and arginine transporting and metabolizing enzymes to NO release and cardiovascular disease.

  7. Longitudinal instabilities affecting the moving critical layer laser-plasma ion accelerators

    CERN Document Server

    Sahai, Aakash Ajit

    2014-01-01

    In this work we analyze the longitudinal instabilities of propagating acceleration structures that are driven by a relativistically intense laser at the moving plasma critical layer [1]. These instabilities affect the energy-spectra of the accelerated ion-beams in propagating critical layer acceleration schemes [2][3]. Specifically, using analytical theory and PIC simulations we look into three fundamental physical processes and their interplay that are crucial to the understanding of energy spectral control by making the laser-plasma ion accelerators stable. The interacting processes are (i) Doppler-shifted ponderomotive bunching [1][4] (ii) potential quenching by beam-loading [2] and (iii) two-stream instabilities. These phenomenon have been observed in simulations analyzing these acceleration processes [5][6][7]. From the preliminary models and results we present in this work, we can infer measures by which these instabilities can be controlled [8] for improving the energy-spread of the beams.

  8. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    Science.gov (United States)

    Ha, Byung Hak; Cho, Ki Joon; Choi, Yu Jin; Park, Ky Young; Kim, Kyung Hyun

    2004-04-01

    Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%. PMID:15120115

  9. Chiral pharmacokinetics and inversion of NG-nitro-arginine in the rat

    Institute of Scientific and Technical Information of China (English)

    Yan-feiXIN; RuiTONG; YangFANG; Xiang-junZHOU; Yong-xiangWANG

    2004-01-01

    AIM: To explore pharmacokinetics of NG-nitro-D-arginine (D-NNA) and NG-nitro-L-arginine (L-NNA) in conscious rats.METHODS: The plasma concentration of D-NNA and L-NNA were determined by chiral ligand exchange method with capillary electrochromatography (CEC). Pharmacokinetic parameters were estimated using non-compartment model and were fitted using a computer program DAS. Chiral inversion rate of D-NNA to L-

  10. Zinc and copper levels in the plasma of Nubian goat as affected by the physiological status

    International Nuclear Information System (INIS)

    This study is undertaken directed to determine the blood concentration of micro (trace) minerals, particularly zinc (Zn) and copper (Cu), in dairy goats as affected by the different physiological status. Animals selected were the Nubian goats as an important dairy breed in sudan. The animals were divided into eight groups as follows: Young animals (4-6 month old), adult animals (9-12 month old), up to 50 days after first kidding, up to 50 days after second kidding, up to 50 days after third kidding, low yielder, high yielder. Each of the above groups consisted of 5 animals. The analysis was carried by using the spectrophotometer technique and the results revealed that, plasma Zn concentration decreased with increase of age while that of Cu increased with the increase of age. The plasma Zn level showed continuous increase through first pregnancy, after first kidding, after second kidding and after third kidding. It increased in the lactating animals. The plasma Cu concentration fluctuated throughout the groups with different physiological status, it showed the same levels in the pregnant group, up to 50 days after second kidding, and up to 50 days after third kidding groups, while it showed a marked decrease in the group of up to 50 days after first kidding. No significant differences were observed between the low lactating and the high lactating groups. (Author)

  11. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe

    Institute of Scientific and Technical Information of China (English)

    Guo-qing DI; Bing ZHOU; Zheng-guang; LI, Qi-li LIN

    2011-01-01

    In order to investigate the physiological effects of airport noise exposure on organisms,in this study,we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d.For comparison,we also used unexposed control rats.Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (LwEcPN) of 75 and 80 dB for the two experimental groups.We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD).We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM).Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (P<0.05) and significantly longer center area duration (P<0.05) than control animals.After 29 d of airport noise exposure,the concentration of plasma NE of exposed rats was significantly higher than that of the control group (P<0.05).We also determined that the neuron and synapsis of the temporal lobe of rats showed signs of damage after aircraft noise of 80 dB exposure for 65 d.In conclusion,exposing rats to long-term aircraft noise affects their behaviors,plasma NE levels,and cell morphology of the temporal lobe.

  12. Some factors affecting the dynamics of a plasma-wall interaction simulator

    International Nuclear Information System (INIS)

    Isotope mixing and thermal desorption from samples exposed in a glow discharge apparatus were used to study the factors affecting hydrogen recycle and wall inventory. Conditions were chosen to be similar to those expected at the walls in today's experimental fusion devices. The size and nature of the hydrogen reservoir in the wall after plasma pulses was investigated by thermal desorption techniques. Large amounts of deuterium, i.e., 5 x 1015 D cm-2 remain in the sample 4 min after a single 200 ms plasma pulse. While this result may be explained by a model using bulk diffusion and traps, it is suggested that either a spectrum of desorption energies, or a concentration dependent recombination coefficient, may also be useful in describing the thermal desorption processes. Experiments with various pumping conditions show that readsorption of molecular hydrogen isotopes on the wall should be considered in modeling hydrogen recycle and isotope changeover processes. HD formation without plasmas confirms the role readsorption plays. (orig.)

  13. Gamma-hydroxybutyrate enhances mood and prosocial behavior without affecting plasma oxytocin and testosterone.

    Science.gov (United States)

    Bosch, Oliver G; Eisenegger, Christoph; Gertsch, Jürg; von Rotz, Robin; Dornbierer, Dario; Gachet, M Salomé; Heinrichs, Markus; Wetter, Thomas C; Seifritz, Erich; Quednow, Boris B

    2015-12-01

    Gamma-hydroxybutyrate (GHB) is a GHB-/GABAB-receptor agonist. Reports from GHB abusers indicate euphoric, prosocial, and empathogenic effects of the drug. We measured the effects of GHB on mood, prosocial behavior, social and non-social cognition and assessed potential underlying neuroendocrine mechanisms. GHB (20mg/kg) was tested in 16 healthy males, using a randomized, placebo-controlled, cross-over design. Subjective effects on mood were assessed by visual-analogue-scales and the GHB-Specific-Questionnaire. Prosocial behavior was examined by the Charity Donation Task, the Social Value Orientation test, and the Reciprocity Task. Reaction time, memory, empathy, and theory-of-mind were also tested. Blood plasma levels of GHB, oxytocin, testosterone, progesterone, dehydroepiandrosterone (DHEA), cortisol, aldosterone, and adrenocorticotropic-hormone (ACTH) were determined. GHB showed stimulating and sedating effects, and elicited euphoria, disinhibition, and enhanced vitality. In participants with low prosociality, the drug increased donations and prosocial money distributions. In contrast, social cognitive abilities such as emotion recognition, empathy, and theory-of-mind, and basal cognitive functions were not affected. GHB increased plasma progesterone, while oxytocin and testosterone, cortisol, aldosterone, DHEA, and ACTH levels remained unaffected. GHB has mood-enhancing and prosocial effects without affecting social hormones such as oxytocin and testosterone. These data suggest a potential involvement of GHB-/GABAB-receptors and progesterone in mood and prosocial behavior. PMID:26209926

  14. Effect of oral take L-arginine on [Ca2+]i of human platelets

    International Nuclear Information System (INIS)

    To study the effect of oral take L-arginine on [Ca2+]i of human platelet, ten male volunteers were selected to take L-arginine for 4 days (20g/three times/a day, the 4th day took about 7g). They are neither smokers nor drinkers and no drugs were taken by them during 2 weeks before study. Tests were performed before and after taking L-arginine. Before and after taking L-arginine, platelet intracellular cGMP were 1.91 ± 0.20 vs 2.14 ± 0.34pmol/109 platelets, P 2+]i (A/B value: 0.45 ± 0.14 vs 0.32 ± 0.09) were inhibited. The results has showed that oral take L-arginine could inhibit platelet activation. This inhibition should be ascribed to such two points: (1) The amount of NO released by endothelial cells has increased. A basal release of NO has been found to regulate the blood vessel intensity and inhibit platelet adhesion. After taking L-arginine, the endothelial cells released more NO and the plasma NO3- level also increased. (2) The platelet has synthesized more NO. There is an L-arginine/NO pathway in platelet and platelet could synthesize NO from L-arginine to inhibit its activation. Taking L-arginine has enhanced the negative effect of this pathway by producing more NO. The study will be helpful to further study on the possibility of oral take L-arginine to avoid thrombotic and hemorrhagic diseases

  15. Reduced arginine availability and nitric oxide synthesis in cancer is related to impaired endogenous arginine synthesis.

    Science.gov (United States)

    Engelen, Mariëlle P K J; Safar, Ahmed M; Bartter, Thaddeus; Koeman, Fari; Deutz, Nicolaas E P

    2016-07-01

    Reduced plasma arginine (ARG) concentrations are found in various types of cancer. ARG and its product nitric oxide (NO) are important mediators in the immune function and the defense against tumour cells. It remains unclear whether the diminished systemic ARG availability in cancer is related to insufficient endogenous ARG synthesis, negatively affecting NO synthesis, and whether a dietary amino acid mixture is able to restore this. In 13 patients with advanced non-small cell lung cancer (NSCLC) and 11 healthy controls, whole body ARG and CIT (citrulline) rates of appearance were measured by stable isotope methodology before and after intake of a mixture of amino acids as present in whey protein. The conversions of CIT to ARG (indicator of de novo ARG synthesis) and ARG to CIT (marker of NO synthesis), and ARG clearance (reflecting ARG disposal capacity) were calculated. Plasma isotopic enrichments and amino acid concentrations were measured by LC-MS/MS. Conversions of CIT to ARG and ARG to CIT (P<0.05), and CIT rate of appearance (P=0.07) were lower in NSCLC. ARG rate of appearance and clearance were comparable suggesting no enhanced systemic ARG production and disposal capacity in NSCLC. After intake of the mixture, ARG rate of appearance and concentration increased (P<0.001), and ARG to CIT conversion was restored in NSCLC. In conclusion, an impaired endogenous ARG synthesis plays a role in the reduced systemic ARG availability and NO synthesis in advanced NSCLC. Nutritional approaches may restore systemic ARG availability and NO synthesis in cancer, but the clinical implication remains unclear. PMID:27129191

  16. Aircraft noise exposure affects rat behavior, plasma norepinephrine levels, and cell morphology of the temporal lobe.

    Science.gov (United States)

    Di, Guo-Qing; Zhou, Bing; Li, Zheng-Guang; Lin, Qi-Li

    2011-12-01

    In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 65 d. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceived noise levels (L(WECPN)) of 75 and 80 dB for the two experimental groups. We examined rat behaviors through an open field test and measured the concentrations of plasma norepinephrine (NE) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). We also examined the morphologies of neurons and synapses in the temporal lobe by transmission electron microscopy (TEM). Our results showed that rats exposed to airport noise of 80 dB had significantly lower line crossing number (Paircraft noise of 80 dB exposure for 65 d. In conclusion, exposing rats to long-term aircraft noise affects their behaviors, plasma NE levels, and cell morphology of the temporal lobe. PMID:22135145

  17. The role of the arginine metabolome in pain: implications for sickle cell disease

    Directory of Open Access Journals (Sweden)

    Bakshi N

    2016-03-01

    Full Text Available Nitya Bakshi,1–2 Claudia R Morris3–6 1Division of Pediatric Hematology-Oncology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA; 2Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA, USA; 3Division of Pediatric Emergency Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA; 4Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA; 5Emory-Children’s Center for Cystic Fibrosis and Airways Disease Research, Emory University School of Medicine, Atlanta, GA, USA; 6Pediatric Emergency Medicine, Children’s Healthcare of Atlanta, Atlanta, GA, USA Abstract: Sickle cell disease (SCD is the most common hemoglobinopathy in the US, affecting approximately 100,000 individuals in the US and millions worldwide. Pain is the hallmark of SCD, and a subset of patients experience pain virtually all of the time. Of interest, the arginine metabolome is associated with several pain mechanisms highlighted in this review. Since SCD is an arginine deficiency syndrome, the contribution of the arginine metabolome to acute and chronic pain in SCD is a topic in need of further attention. Normal arginine metabolism is impaired in SCD through various mechanisms that contribute to endothelial dysfunction, vaso-occlusion, pulmonary complications, risk of leg ulcers, and early mortality. Arginine is a semiessential amino acid that serves as a substrate for protein synthesis and is the precursor to nitric oxide (NO, polyamines, proline, glutamate, creatine, and agmatine. Since arginine is involved in multiple metabolic processes, a deficiency of this amino acid has the potential to disrupt many cellular and organ functions. NO is a potent vasodilator that is depleted in SCD and may contribute to vaso-occlusive pain. As the obligate substrate for NO production, arginine also plays a mechanistic role in SCD-related pain, although its

  18. Arginase and Arginine Dysregulation in Asthma

    OpenAIRE

    Renée C. Benson; Hardy, Karen A.; Morris, Claudia R.

    2011-01-01

    In recent years, evidence has accumulated indicating that the enzyme arginase, which converts L-arginine into L-ornithine and urea, plays a key role in the pathogenesis of pulmonary disorders such as asthma through dysregulation of L-arginine metabolism and modulation of nitric oxide (NO) homeostasis. Allergic asthma is characterized by airway hyperresponsiveness, inflammation, and remodeling. Through substrate competition, arginase decreases bioavailability of L-arginine for nitric oxide syn...

  19. Physiological implications of arginine metabolism in plants.

    Science.gov (United States)

    Winter, Gudrun; Todd, Christopher D; Trovato, Maurizio; Forlani, Giuseppe; Funck, Dietmar

    2015-01-01

    Nitrogen is a limiting resource for plant growth in most terrestrial habitats since large amounts of nitrogen are needed to synthesize nucleic acids and proteins. Among the 21 proteinogenic amino acids, arginine has the highest nitrogen to carbon ratio, which makes it especially suitable as a storage form of organic nitrogen. Synthesis in chloroplasts via ornithine is apparently the only operational pathway to provide arginine in plants, and the rate of arginine synthesis is tightly regulated by various feedback mechanisms in accordance with the overall nutritional status. While several steps of arginine biosynthesis still remain poorly characterized in plants, much wider attention has been paid to inter- and intracellular arginine transport as well as arginine-derived metabolites. A role of arginine as alternative source besides glutamate for proline biosynthesis is still discussed controversially and may be prevented by differential subcellular localization of enzymes. Apparently, arginine is a precursor for nitric oxide (NO), although the molecular mechanism of NO production from arginine remains unclear in higher plants. In contrast, conversion of arginine to polyamines is well documented, and in several plant species also ornithine can serve as a precursor for polyamines. Both NO and polyamines play crucial roles in regulating developmental processes as well as responses to biotic and abiotic stress. It is thus conceivable that arginine catabolism serves on the one hand to mobilize nitrogen storages, while on the other hand it may be used to fine-tune development and defense mechanisms against stress. This review summarizes the recent advances in our knowledge about arginine metabolism, with a special focus on the model plant Arabidopsis thaliana, and pinpoints still unresolved critical questions. PMID:26284079

  20. Analysis of surface roughness and surface heat affected zone of steel S355J0 after plasma arc cutting

    International Nuclear Information System (INIS)

    This paper deals with thermal cutting technology of materials with plasma arc. In the first part of this paper the theoretical knowledge of the principles of plasma arc cutting and current use of this technology in industry are presented. The cut of products with this technology is perpendicular and accurate, but the use of this technology affects micro-structural changes and depth of the heat affected zone (HAZ). This article deals with the experimental evaluation of plasma arc cutting technological process. The influence of technological factors on the roughness parameter Ra of the steel surface EN S355J0 has been evaluated by using planned experiments. By using the factor experiment, the significance of the four process factors such as plasma burner feed speed, plasma gas pressure, nozzle diameter, distance between nozzle mouth and material has been analyzed. Regression models obtained by multiple linear regression indicate the quality level of observed factors function. The heat from plasma arc cutting affects the micro-structural changes of the material, too.

  1. Arginase activities and global arginine bioavailability in wild-type and ApoE-deficient mice: responses to high fat and high cholesterol diets.

    Directory of Open Access Journals (Sweden)

    Aaron Erdely

    Full Text Available Increased catabolism of arginine by arginase is increasingly viewed as an important pathophysiological factor in cardiovascular disease, including atherosclerosis induced by high cholesterol diets. Whereas previous studies have focused primarily on effects of high cholesterol diets on arginase expression and arginine metabolism in specific blood vessels, there is no information regarding the impact of lipid diets on arginase activity or arginine bioavailability at a systemic level. We, therefore, evaluated the effects of high fat (HF and high fat-high cholesterol (HC diets on arginase activity in plasma and tissues and on global arginine bioavailability (defined as the ratio of plasma arginine to ornithine + citrulline in apoE(-/- and wild-type C57BL/6J mice. HC and HF diets led to reduced global arginine bioavailability in both strains. The HC diet resulted in significantly elevated plasma arginase in both strains, but the HF diet increased plasma arginase only in apoE(-/- mice. Elevated plasma arginase activity correlated closely with increased alanine aminotransferase levels, indicating that liver damage was primarily responsible for elevated plasma arginase. The HC diet, which promotes atherogenesis, also resulted in increased arginase activity and expression of the type II isozyme of arginase in multiple tissues of apoE(-/- mice only. These results raise the possibility that systemic changes in arginase activity and global arginine bioavailability may be contributing factors in the initiation and/or progression of cardiovascular disease.

  2. Mechanism of arginine regulation of acetylglutamate synthase, the first enzyme of arginine synthesis.

    Science.gov (United States)

    Sancho-Vaello, Enea; Fernández-Murga, María L; Rubio, Vicente

    2009-01-01

    N-acetyl-L-glutamate synthase (NAGS), the first enzyme of arginine biosynthesis in bacteria/plants and an essential urea cycle activator in animals, is, respectively, arginine-inhibited and activated. Arginine binds to the hexameric ring-forming amino acid kinase (AAK) domain of NAGS. We show that arginine inhibits Pseudomonas aeruginosa NAGS by altering the functions of the distant, substrate binding/catalytic GCN5-related N-acetyltransferase (GNAT) domain, increasing K(m)(Glu), decreasing V(max) and triggering substrate inhibition by AcCoA. These effects involve centrally the interdomain linker, since we show that linker elongation or two-residue linker shortening hampers and mimics, respectively, arginine inhibition. We propose a regulatory mechanism in which arginine triggers the expansion of the hexameric NAGS ring, altering AAK-GNAT domain interactions, and the modulation by these interactions of GNAT domain functions, explaining arginine regulation. PMID:19084009

  3. L-Arginine but not L-glutamine likely increases exogenous carbohydrate oxidation during endurance exercise.

    Science.gov (United States)

    Rowlands, David S; Clarke, Jim; Green, Jackson G; Shi, Xiaocai

    2012-07-01

    The addition of L-arginine or L-glutamine to glucose-electrolyte solutions can increase intestinal water, glucose, and sodium absorption in rats and humans. We evaluated the utility of L-arginine and L-glutamine in energy-rehydration beverages through assessment of exogenous glucose oxidation and perceptions of exertion and gastrointestinal distress during endurance exercise. Eight cyclists rode 150 min at 50% of peak power on four occasions while ingesting solutions at a rate of 150 mL 15 min(-1) that contained (13)C-enriched glucose (266 mmol L(-1)) and sodium citrate ([Na(+)] 60 mmol L(-1)), and either: 4.25 mmol L(-1) L-arginine or 45 mmol L(-1) L-glutamine, and as controls glucose only or no glucose. Relative to glucose only, L-arginine invoked a likely 12% increase in exogenous glucose oxidation (90% confidence limits: ± 8%); however, the effect of L-glutamine was possibly trivial (4.5 ± 7.3%). L-Arginine also led to very likely small reductions in endogenous fat oxidation rate relative to glucose (12 ± 4%) and L-glutamine (14 ± 4%), and relative to no glucose, likely reductions in exercise oxygen consumption (2.6 ± 1.5%) and plasma lactate concentration (0.20 ± 0.16 mmol L(-1)). Effects on endogenous and total carbohydrate oxidation were inconsequential. Compared with glucose only, L-arginine and L-glutamine caused likely small-moderate effect size increases in perceptions of stomach fullness, abdominal cramp, exertion, and muscle tiredness during exercise. Addition of L-arginine to a glucose and electrolyte solution increases the oxidation of exogenous glucose and decreases the oxygen cost of exercise, although the mechanisms responsible and impact on endurance performance require further investigation. However, L-arginine also increases subjective feelings of gastrointestinal distress, which may attenuate its other benefits. PMID:22048324

  4. Nonspecific blockade of vascular free radical signals by methylated arginine analogues

    Directory of Open Access Journals (Sweden)

    Pedro M.A.

    1998-01-01

    Full Text Available Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol/l, P<0.001 in response to papaverine-induced flow increases of 121 ± 12%. In contrast, after similar papaverine-induced flow increases simultaneously with L-NMMA infusions, ascorbyl levels were not significantly changed compared to baseline. Similar results were obtained in isolated rabbit aortas perfused ex vivo with the spin trap a-phenyl-N-tert-butylnitrone (N = 22. However, in both preparations, this complete blockade was not reversed by co-infusion of excess L-arginine and was also obtained by N-methyl-D-arginine, thus indicating that it is not related to nitric oxide synthase. L-arginine alone was ineffective, as previously demonstrated for NG-methyl-L-arginine ester (L-NAME. In vitro, neither L-arginine nor its analogues scavenged superoxide radicals. This nonspecific activity of methylated arginine analogues underscores the need for careful controls in order to assess nitric oxide effects, particularly those related to interactions with active oxygen species.

  5. A lignan complex isolated from flaxseed does not affect plasma lipid concentrations or antioxidant capacity in healthy postmenopausal women

    DEFF Research Database (Denmark)

    Hallund, Jesper; Ravn-Haren, Gitte; Bügel, S.; Tholstrup, T.; Tetens, Inge

    2006-01-01

    ) completed a randomized, double-blind, placebo-controlled, crossover study. Women consumed daily a low-fat muffin, with or without a lignan complex, for 6 wk, separated by a 6-wk washout period. Serum ENL concentration, urinary ENL excretion, plasma concentrations of total cholesterol (TC), LDL cholesterol.......001) and ENL urinary excretion (P <0.001) were significantly higher after the lignan complex intervention period compared with placebo. Plasma concentrations of TC, LDL-C, HDL-C, TAG, lipoprotein oxidation lag time, TEAC and FRAP were not affected. Daily consumption for 6 wk of a low-fat muffin enriched...

  6. Plasma sprayed cylinder lining coatings : Factors affecting the amount of ceramics in plasma sprayed cylinder lining coatings

    OpenAIRE

    Antonsson Nilsson, Hermina; Jarnerud, Tova

    2015-01-01

    Scania uses powder plasma spray technology to coat their cylinder linings. The powder used contains stainless steel and ceramics. In order for the properties of the coating to reach the quality demands, it has to have a certain amount of pores and ceramics in it. Despite the process being strictly controlled the coating has proven to exhibit differences in composition. Process parameters for each coated lining are logged and as part of Scania’s quality control, samples of the coating are freq...

  7. RNAi-mediated downregulation of poplar plasma membrane intrinsic proteins (PIPs) changes plasma membrane proteome composition and affects leaf physiology.

    Science.gov (United States)

    Bi, Zhen; Merl-Pham, Juliane; Uehlein, Norbert; Zimmer, Ina; Mühlhans, Stefanie; Aichler, Michaela; Walch, Axel Karl; Kaldenhoff, Ralf; Palme, Klaus; Schnitzler, Jörg-Peter; Block, Katja

    2015-10-14

    Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement. PMID:26248320

  8. Arginine metabolism by macrophages promotes cardiac and muscle fibrosis in mdx muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Michelle Wehling-Henricks

    Full Text Available BACKGROUND: Duchenne muscular dystrophy (DMD is the most common, lethal disease of childhood. One of 3500 new-born males suffers from this universally-lethal disease. Other than the use of corticosteroids, little is available to affect the relentless progress of the disease, leading many families to use dietary supplements in hopes of reducing the progression or severity of muscle wasting. Arginine is commonly used as a dietary supplement and its use has been reported to have beneficial effects following short-term administration to mdx mice, a genetic model of DMD. However, the long-term effects of arginine supplementation are unknown. This lack of knowledge about the long-term effects of increased arginine metabolism is important because elevated arginine metabolism can increase tissue fibrosis, and increased fibrosis of skeletal muscles and the heart is an important and potentially life-threatening feature of DMD. METHODOLOGY: We use both genetic and nutritional manipulations to test whether changes in arginase metabolism promote fibrosis and increase pathology in mdx mice. Our findings show that fibrotic lesions in mdx muscle are enriched with arginase-2-expressing macrophages and that muscle macrophages stimulated with cytokines that activate the M2 phenotype show elevated arginase activity and expression. We generated a line of arginase-2-null mutant mdx mice and found that the mutation reduced fibrosis in muscles of 18-month-old mdx mice, and reduced kyphosis that is attributable to muscle fibrosis. We also observed that dietary supplementation with arginine for 17-months increased mdx muscle fibrosis. In contrast, arginine-2 mutation did not reduce cardiac fibrosis or affect cardiac function assessed by echocardiography, although 17-months of dietary supplementation with arginine increased cardiac fibrosis. Long-term arginine treatments did not decrease matrix metalloproteinase-2 or -9 or increase the expression of utrophin, which have

  9. Nonspecific blockade of vascular free radical signals by methylated arginine analogues

    OpenAIRE

    Pedro M.A.; Augusto O.; Barbeiro H.V.; Carvalho M.H.C.; da-Luz P.L.; Laurindo F.R.M.

    1998-01-01

    Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA) on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol...

  10. Genetic and biochemical characterization of arginine biosynthesis in Sinorhizobium meliloti 1021.

    Science.gov (United States)

    Hernández, Victor M; Girard, Lourdes; Hernández-Lucas, Ismael; Vázquez, Alejandra; Ortíz-Ortíz, Catalina; Díaz, Rafael; Dunn, Michael F

    2015-08-01

    L-Ornithine production in the alfalfa microsymbiont Sinorhizobium meliloti occurs as an intermediate step in arginine biosynthesis. Ornithine is required for effective symbiosis but its synthesis in S. meliloti has been little studied. Unlike most bacteria, S. meliloti 1021 is annotated as encoding two enzymes producing ornithine: N-acetylornithine (NAO) deacetylase (ArgE) hydrolyses NAO to acetate and ornithine, and glutamate N-acetyltransferase (ArgJ) transacetylates l-glutamate with the acetyl group from NAO, forming ornithine and N-acetylglutamate (NAG). NAG is the substrate for the second step of arginine biosynthesis catalysed by NAG kinase (ArgB). Inactivation of argB in strain 1021 resulted in arginine auxotrophy. The activity of purified ArgB was significantly inhibited by arginine but not by ornithine. The purified ArgJ was highly active in NAO deacetylation/glutamate transacetylation and was significantly inhibited by ornithine but not by arginine. The purified ArgE protein (with a 6His-Sumo affinity tag) was also active in deacetylating NAO. argE and argJ single mutants, and an argEJ double mutant, are arginine prototrophs. Extracts of the double mutant contained aminoacylase (Ama) activity that deacetylated NAO to form ornithine. The purified products of three candidate ama genes (smc00682 (hipO1), smc02256 (hipO2) and smb21279) all possessed NAO deacetylase activity. hipO1 and hipO2, but not smb21279, expressed in trans functionally complemented an Escherichia coli ΔargE : : Km mutant. We conclude that Ama activity accounts for the arginine prototrophy of the argEJ mutant. Transcriptional assays of argB, argE and argJ, fused to a promoterless gusA gene, showed that their expression was not significantly affected by exogenous arginine or ornithine. PMID:26271664

  11. Plasma taurine levels are not affected by vigabatrin in pediatric patients.

    Science.gov (United States)

    Spelbrink, Emily M; Mabud, Tarub S; Reimer, Richard; Porter, Brenda E

    2016-08-01

    Vigabatrin is a highly effective antiseizure medication, but its use is limited due to concerns about retinal toxicity. One proposed mechanism for this toxicity is vigabatrin-mediated reduction of taurine. Herein we assess plasma taurine levels in a retrospective cohort of children with epilepsy, including a subset receiving vigabatrin. All children who underwent a plasma amino acid analysis as part of their clinical evaluation between 2006 and 2015 at Stanford Children's Health were included in the analysis. There were no significant differences in plasma taurine levels between children taking vigabatrin (n = 16), children taking other anti-seizure medications, and children not taking any anti-seizure medication (n = 556) (analysis of variance [ANOVA] p = 0.841). There were, however, age-dependent decreases in plasma taurine levels. Multiple linear regression revealed no significant association between vigabatrin use and plasma taurine level (p = 0.87) when controlling for age. These results suggest that children taking vigabatrin maintain normal plasma taurine levels, although they leave unanswered whether taurine supplementation is necessary or sufficient to prevent vigabatrin-associated visual field loss. They also indicate that age should be taken into consideration when evaluating taurine levels in young children. PMID:27344989

  12. Seminal plasma applied post-thawing affects boar sperm physiology: a flow cytometry study.

    Science.gov (United States)

    Fernández-Gago, Rocío; Domínguez, Juan Carlos; Martínez-Pastor, Felipe

    2013-09-01

    Cryopreservation induces extensive biophysical and biochemical changes in the sperm. In the present study, we used flow cytometry to assess the capacitation-like status of frozen-thawed boar spermatozoa and its relationship with intracellular calcium, assessment of membrane fluidity, modification of thiol groups in plasma membrane proteins, reactive oxygen species (ROS) levels, viability, acrosomal status, and mitochondrial activity. This experiment was performed to verify the effect of adding seminal plasma on post-thaw sperm functions. To determine these effects after cryopreservation, frozen-thawed semen from seven boars was examined after supplementation with different concentrations of pooled seminal plasma (0%, 10%, and 50%) at various times of incubation from 0 to 4 hours. Incubation caused a decrease in membrane integrity and an increase in acrosomal damage, with small changes in other parameters (P > 0.05). Although 10% seminal plasma showed few differences with 0% (ROS increase at 4 hours, P boar spermatozoa, possibly through membrane changes and ROS increase. Although some effects were detrimental, the stimulatory effect of 50% seminal plasma could favor the performance of post-thawed boar semen, as showed in the field (García JC, Domínguez JC, Peña FJ, Alegre B, Gonzalez R, Castro MJ, Habing GG, Kirkwood RN. Thawing boar semen in the presence of seminal plasma: effects on sperm quality and fertility. Anim Reprod Sci 2010;119:160-5). PMID:23756043

  13. Plasma of Argon Affects the Earliest Biological Response of Different Implant Surfaces: An In Vitro Comparative Study.

    Science.gov (United States)

    Canullo, L; Genova, T; Tallarico, M; Gautier, G; Mussano, F; Botticelli, D

    2016-05-01

    The aim of this in vitro study was to evaluate the early cell response and protein adsorption elicited by the argon plasma treatment of different commercially available titanium surfaces via a chair-side device. Sterile disks made of grade 4 titanium (n= 450, 4-mm diameter) with 3 surface topographies (machined, plasma sprayed, and zirconia blasted and acid etched) were allocated to receive 4 testing treatments (2% and 10% protein adsorption and cell adhesion with MC3T3-E1 and MG-63). Furthermore, the specimens were divided to undergo 1) argon plasma treatment (10 W, 1 bar for 12 min) in a plasma reactor, 2) ultraviolet (UV) light treatment for 2 h (positive control group), or 3) no treatment (control group). Pretreatment surface analyses based on a scanning electron microscope and profilometer images were also performed. Profilometric analysis demonstrated that the evaluated specimens perfectly suit the standard parameters. The use of argon plasma was capable of affecting the quantity of proteins adsorbed on the different surfaces, notwithstanding their roughness or topographic features at a low fetal bovine serum concentration (2%). UV light treatment for 2 h attained similar results. Moreover, both the plasma of argon and the UV light demonstrated a significant increase in the number of osteoblasts adherent at 10 min in all tested surfaces. Within its limitations, this in vitro study highlights the potential biological benefits of treating implant surfaces with plasma of argon or UV, irrespective of the roughness of the titanium surface. However, in vivo experiments are needed to confirm these preliminary data and settle the rationale of a treatment that might be clinically relevant in case of bone-reparative deficiencies. PMID:26848069

  14. Effects of Arginine Supplementation on Amino Acid Profiles in Blood and Tissues in Fed and Overnight-Fasted Rats

    Directory of Open Access Journals (Sweden)

    Milan Holecek

    2016-04-01

    Full Text Available Chronic arginine intake is believed to have favorable effects on the body. However, it might be hypothesized that excessive consumption of an individual amino acid exerts adverse effects on distribution and metabolism of other amino acids. We evaluated the effect of chronic intake of arginine on amino acid concentrations in blood plasma, liver, kidneys, and soleus and extensor digitorum longus muscles. Rats were fed a standard diet or a high-arginine diet (HAD for two months. Half of the animals in each group were sacrificed in the fed state, and the other half after fasting overnight. HAD increased blood plasma concentrations of urea, creatinine, arginine, and ornithine and decreased most other amino acids. Arginine and ornithine also increased in muscles and kidneys; an increase of lysine was observed in both muscle types. Methionine, phenylalanine, threonine, asparagine, glycine, serine, and taurine decreased in most tissues of HAD fed animals. Most of the effects of HAD disappeared after overnight fasting. It is concluded that (i enhanced dietary arginine intake alters distribution of almost all amino acids; and (ii to attain a better assessment of the effects of various nutritional interventions, an appropriate number of biochemical measurements must be performed in both postprandial and postabsorptive states.

  15. Effects of Arginine Supplementation on Amino Acid Profiles in Blood and Tissues in Fed and Overnight-Fasted Rats.

    Science.gov (United States)

    Holecek, Milan; Sispera, Ludek

    2016-01-01

    Chronic arginine intake is believed to have favorable effects on the body. However, it might be hypothesized that excessive consumption of an individual amino acid exerts adverse effects on distribution and metabolism of other amino acids. We evaluated the effect of chronic intake of arginine on amino acid concentrations in blood plasma, liver, kidneys, and soleus and extensor digitorum longus muscles. Rats were fed a standard diet or a high-arginine diet (HAD) for two months. Half of the animals in each group were sacrificed in the fed state, and the other half after fasting overnight. HAD increased blood plasma concentrations of urea, creatinine, arginine, and ornithine and decreased most other amino acids. Arginine and ornithine also increased in muscles and kidneys; an increase of lysine was observed in both muscle types. Methionine, phenylalanine, threonine, asparagine, glycine, serine, and taurine decreased in most tissues of HAD fed animals. Most of the effects of HAD disappeared after overnight fasting. It is concluded that (i) enhanced dietary arginine intake alters distribution of almost all amino acids; and (ii) to attain a better assessment of the effects of various nutritional interventions, an appropriate number of biochemical measurements must be performed in both postprandial and postabsorptive states. PMID:27070638

  16. Efficacy L-Arginine In Patients With Nonalcoholic Steatohepatitis Associated With Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Oleksandr Fediv

    2015-01-01

    Full Text Available Abstract Background and Purpose Recent research in the field of hematology indicate that among the many pathogenic mechanisms of development and progression of nonalcoholic steatohepatitis NASH which occurs on the background of the metabolic syndrome an important role is played by endothelial dysfunction and violations of haemocoagulation. The aim of this research was to study the effectiveness of L-arginine as it corrects endothelial dysfunction and disorders of homeostasis haemocoagulation link in patients with NASH associated with the metabolic syndrome. Subjects and Methods 128 patients with nonalcoholic steatohepatitis associated with metabolic syndrome were examined. Some patients 63 persons received standard treatment according to national guidelines. To another group 65 patients on the background of basic therapy L-arginine hydrochloride followed by transition to oral form of L-arginine aspartate was administered. Blood levels of stable nitrogen monoxide metabolites nitrites nitrates endothelin-1 and plasma recalcification time prothrombin time thrombin time activated partial thromboplastin time fibrinogen plasma level activity of antithrombin III and coagulation factor XIII potential activity of plasminogen plasma fibrinolytic blood activity were studied. Results Originally significantly increased levels of endothelin-1 decreased after the therapy in all studied groups but more noticeable changes in the group with L-arginine appointment were observed p0.05. In the studied groups normalization of stable nitrogen monoxide metabolites after treatment was also noticed. Significant p0.05 increase in all haemocoagulation time characteristics and activities of antithrombin-III and factor XIII was found. The positive effect of L-arginine on blood fibrinolytic activity was noted. Discussion and Conclusion Combined therapy of nonalcoholic steatohepatitis associated with metabolic syndrome with a differentiated degreeal L-arginine assignment by

  17. HAEMATOLOGICAL VALUES AND PLASMA CHOLESTEROL AS AFFECTED BY MOULTING IN NICK CHICK LAYING HENS

    OpenAIRE

    Bashir Mahmood Bhatti and Tanzeela Talat

    2001-01-01

    This study was conducted to examine effect of moulting on haematological values and plasma cholesterol levels of 86 weeks old Nick Chick laying hens. Washington and California moulting methods were used. Young laying hens, 40 weeks old served as control group. There were 408 hens in each group. There was no significant (P

  18. Plasma membrane lipid-protein interactions affect signaling processes in sterol-biosynthesis mutants of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Henrik eZauber

    2014-03-01

    Full Text Available The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein-protein and protein-lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid-protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status.

  19. The preferential nNOS inhibitor 7-nitroindazole and the non-selective one N(G)-nitro-L-arginine methyl ester administered alone or jointly with L-DOPA differentially affect motor behavior and monoamine metabolism in sham-operated and 6-OHDA-lesioned rats.

    Science.gov (United States)

    Czarnecka, Anna; Konieczny, Jolanta; Lenda, Tomasz; Lorenc-Koci, Elżbieta

    2015-11-01

    Reciprocal interactions between nitrergic and dopaminergic systems play a key role in the control of motor behavior. In the present study, we performed a comparative analysis of motor behavior (locomotor activity, catalepsy, rotational behavior) and monoamine metabolism in the striatum and substantia nigra of unilaterally sham-operated and 6-OHDA-lesioned rats treated with the preferential neuronal nitric oxide synthase (nNOS) inhibitor 7-nitroindazole (7-NI) or the non-selective one N(G)-nitro-L-arginine methyl ester (L-NAME), alone or in combination with L-DOPA. Each NOS inhibitor given alone (50mg/kg) induced a distinct catalepsy 30 min after injection but only 7-NI impaired spontaneous locomotion after 10 min. In 6-OHDA-lesioned rats, chronic L-DOPA (25mg/kg) induced 2.5-h long contralateral rotations. 7-NI (30 and 50mg/kg) markedly reduced the intensity of L-DOPA-induced contralateral rotations while extending their duration until 4.5h whereas L-NAME (50 and 100mg/kg) only tended to attenuate their intensity without affecting the duration. 7-NI but not L-NAME significantly increased endogenous tissue DA levels in the nigrostriatal system of both sham-operated and 6-OHDA-lesioned rats. In L-DOPA-treated group, 7-NI significantly enhanced the L-DOPA-derived tissue DA content in this system and decreased the level of the intracellular DA metabolite DOPAC produced by monoamine oxidase (MAO). In contrast to 7-NI, L-NAME decreased markedly DA content and did not affect DOPAC level in the ipsilateral striatum. It means that the differences in 7-NI and L-NAME-mediated modulation of L-DOPA-induced behavioral and biochemical effects resulted not only from the inhibition of NOS activity but also from differences in their ability to inhibit MAO. PMID:26319690

  20. Arginine Adjunctive Therapy in Active Tuberculosis

    Directory of Open Access Journals (Sweden)

    Aliasghar Farazi

    2015-01-01

    Full Text Available Background. Dietary supplementation has been used as a mechanism to augment the immune system. Adjunctive therapy with L-arginine has the potential to improve outcomes in active tuberculosis. Methods. In a randomized clinical trial 63 participants with smear-positive pulmonary tuberculosis in Markazi Province of Iran were given arginine or placebo for 4 weeks in addition to conventional chemotherapy. The final treatment success, sputum conversion, weight gain, and clinical symptoms after one and two months were considered as primary outcomes and secondary outcomes were ESR, CRP, and Hg. Data were collected and analyzed with SPSS software (ver. 18. Results. Arginine supplementation reduced constitutional symptoms (P=0.032 in patients with smear-positive TB at the end of the first month of treatment. Arginine treated patients had significantly increased BMI at the end of the first and second months of treatment (P=0.032 and P=0.04 and a reduced CRP at the end of the first month of treatment (P=0.03 versus placebo group. Conclusion. Arginine is useful as an adjunctive therapy in patients with active tuberculosis, in which the effects are more likely mediated by the increased production of nitric oxide and improved constitutional symptoms and weight gain. This trial is registered with Clinical Trials Registry of Iran: IRCT201211179855N2.

  1. Arginase and Arginine Dysregulation in Asthma

    Directory of Open Access Journals (Sweden)

    Renée C. Benson

    2011-01-01

    Full Text Available In recent years, evidence has accumulated indicating that the enzyme arginase, which converts L-arginine into L-ornithine and urea, plays a key role in the pathogenesis of pulmonary disorders such as asthma through dysregulation of L-arginine metabolism and modulation of nitric oxide (NO homeostasis. Allergic asthma is characterized by airway hyperresponsiveness, inflammation, and remodeling. Through substrate competition, arginase decreases bioavailability of L-arginine for nitric oxide synthase (NOS, thereby limiting NO production with subsequent effects on airway tone and inflammation. By decreasing L-arginine bioavailability, arginase may also contribute to the uncoupling of NOS and the formation of the proinflammatory oxidant peroxynitrite in the airways. Finally, arginase may play a role in the development of chronic airway remodeling through formation of L-ornithine with downstream production of polyamines and L-proline, which are involved in processes of cellular proliferation and collagen deposition. Further research on modulation of arginase activity and L-arginine bioavailability may reveal promising novel therapeutic strategies for asthma.

  2. Arginine, scurvy and Cartier's "tree of life"

    Directory of Open Access Journals (Sweden)

    Durzan Don J

    2009-02-01

    Full Text Available Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors.

  3. Platelet Concentration in Platelet-Rich Plasma Affects Tenocyte Behavior In Vitro

    OpenAIRE

    Ilaria Giusti; Sandra D’Ascenzo; Annalisa Mancò; Gabriella Di Stefano; Marianna Di Francesco; Anna Rughetti; Antonella Dal Mas; Gianfranco Properzi; Vittorio Calvisi; Vincenza Dolo

    2014-01-01

    Since tendon injuries and tendinopathy are a growing problem, sometimes requiring surgery, new strategies that improve conservative therapies are needed. Platelet-rich plasma (PRP) seems to be a good candidate by virtue of its high content of growth factors, most of which are involved in tendon healing. This study aimed to evaluate if different concentrations of platelets in PRP have different effects on the biological features of normal human tenocytes that are usually required during tendon...

  4. Inhibition of sphingomyelin synthase (SMS) affects intracellular sphingomyelin accumulation and plasma membrane lipid organization

    OpenAIRE

    Li, Zhiqiang; Hailemariam, Tiruneh K.; Zhou, Hongwen; Li, Yan; Duckworth, Dale C.; Peake, David A.; Zhang, Youyan; Kuo, Ming-Shang; Cao, Guoqing; Jiang, Xian-Cheng

    2007-01-01

    Sphingomyelin plays a very important role both in cell membrane formation that may well have an impact on the development of diseases like atherosclerosis and diabetes. However, the molecular mechanism that governs intracellular and plasma membrane SM levels is largely unknown. Recently, two isoforms of sphingomyelin synthase (SMS1 and SMS2), the last enzyme for SM de novo synthesis, have been cloned. We have hypothesized that SMS1 and SMS2 are the two most likely candidates responsible for t...

  5. Nature of sterols affects plasma membrane behavior and yeast survival during dehydration.

    OpenAIRE

    Dupont, Sébastien; Beney, Laurent; Ferreira, Thierry; Gervais, Patrick

    2011-01-01

    The plasma membrane (PM) is a main site of injury during osmotic perturbation. Sterols, major lipids of the PM structure in eukaryotes, are thought to play a role in ensuring the stability of the lipid bilayer during physicochemical perturbations. Here, we investigated the relationship between the nature of PM sterols and resistance of the yeast Saccharomyces cerevisiae to hyperosmotic treatment. We compared the responses to osmotic dehydration (viability, sterol quantification, ultrastructur...

  6. Plasma Procalcitonin Concentration in Healthy Horses and Horses Affected by Systemic Inflammatory Response Syndrome

    OpenAIRE

    Bonelli, F.; Meucci, V.; Divers, T.J.; Jose‐Cunilleras, E.; Corazza, M; Tognetti, R; Guidi, G.; Intorre, L.; Sgorbini, M.

    2015-01-01

    Background The diseases most frequent associated with SIRS in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with SIRS. Objective The objective of this study was to evaluate the plasma procalcitonin (PCT) concentration in healthy and SIRS horses to assess differences between the two groups. Animals Seventy‐eight horses (30 healthy and 48 SIRS). Methods Prospective in vivo multicentric study. Horses were classified...

  7. Long-term high fructose and saturated fat diet affects plasma fatty acid profile in rats

    Institute of Scientific and Technical Information of China (English)

    Fabrice TRANCHIDA; Léopold TCHIAKPE; Zo RAKOTONIAINA; Valérie DEYRIS; Olivier RAVION; Abel HIOL

    2012-01-01

    As the consumption of fructose and saturated fatty acids (FAs) has greatly increased in western diets and is linked with an increased risk of metabolic syndrome,the aim of this study was to investigate the effects of a moderate (10 weeks) and a prolonged (30 weeks) high fructose and saturated fatty acid (HFS) diet on plasma FA composition in rats.The effects of a few weeks of HFS diet had already been described,but in this paper we tried to establish whether these effects persist or if they are modified after 10 or 30 weeks.We hypothesized that the plasma FA profile would be altered between 10 and 30 weeks of the HFS diet.Rats fed with either the HFS or a standard diet were tested after 10 weeks and again after 30 weeks.After 10 weeks of feeding,HFS-fed rats developed the metabolic syndrome,as manifested by an increase in fasting insulinemia,total cholesterol and triglyceride levels,as well as by impaired glucose tolerance.Furthermore,the plasma FA profile of the HFS group showed higher proportions of monounsaturated FAs like palmitoleic acid [16:1(n-7)] and oleic acid [18:1(n-9)],whereas the proportions of some polyunsaturated n-6 FAs,such as linoleic acid [18:2(n-6)] and arachidonic acid [20:4(n-6)],were lower than those in the control group.After 30 weeks of the HFS diet,we observed changes mainly in the levels of 16:1(n-7) (decreased)and 20:4(n-6) (increased).Together,our results suggest that an HFS diet could lead to an adaptive response of the plasma FA profile over time,in association with the development of the metabolic syndrome.

  8. Altered plasma pharmacokinetics of ceftiofur hydrochloride in cows affected with severe clinical mastitis.

    Science.gov (United States)

    Gorden, P J; Kleinhenz, M D; Wulf, L W; KuKanich, B; Lee, C J; Wang, C; Coetzee, J F

    2016-01-01

    Mastitis is a frequent problem among dairy cows, reducing milk yield and increasing cull rates. Systemic therapy with the cephalosporin antimicrobial ceftiofur hydrochloride (CEF) may improve therapeutic outcomes, but the incidence of CEF violative residues has increased annually since 2011. One potential explanation is that disease status may alter the pharmacokinetics (PK) of CEF. To test this hypothesis, we compared the plasma PK of CEF in healthy cows with those with severe endotoxic mastitis. Eight cows with naturally occurring mastitis and 8 clinically healthy cows were treated with 2.2 mg of CEF per kilogram of body weight once daily for 5d via the intramuscular route. Blood was collected at 0, 0.33, 0.67, 1, 1.5, 2, 3, 4, 8, 16, and 24h after the first CEF administration and every 8h thereafter until 120 h after the final dose. Plasma samples were analyzed for CEF concentrations using liquid chromatography coupled with mass spectrometry. With the exception of time 0, CEF was detected at all time points. The disease group had a significantly higher plasma CEF concentration at t=3h after the first injection and a significantly lower plasma concentration from 40 to 152 h following the first injection, with the exception of the t=64 h time point. Data following the first injection (time 0-24 h) were fit to a single-dose, noncompartmental PK model. This model indicated that the disease group had a shorter plasma half-life. A multidose, noncompartmental model was used to determine steady-state PK. Compared with control cows, the disease group had an initially higher peak concentration and a higher volume of distribution and drug clearance rates. The disease group also had a lower area under the curve per dosing interval, steady-state concentration maximum, and dose-adjusted peak steady-state concentration. All other PK parameters were not different between the 2 groups. Altered PK, as suggested by this trial, may contribute to an increased risk for the

  9. Differential role of arginine mutations on the structure and functions of α-crystallin☆

    Science.gov (United States)

    Panda, Alok Kumar; Nandi, Sandip Kumar; Chakraborty, Ayon; Nagaraj, Ram H.; Biswas, Ashis

    2016-01-01

    Background α-Crystallin is a major protein of the eye lens in vertebrates. It is composed of two subunits, αA- and αB-crystallin. α-Crystallin is an oligomeric protein having these two subunits in 3:1 ratio. It belongs to small heat shock protein family and exhibits molecular chaperone function, which plays an important role in maintaining the lens transparency. Apart from chaperone function, both subunits also exhibit anti-apoptotic property. Comparison of their primary sequences reveals that αA- and αB-crystallin posses 13 and 14 arginine residues, respectively. Several of them undergo mutations which eventually lead to various eye diseases such as congenital cataract, juvenile cataract, and retinal degeneration. Interestingly, many arginine residues of these subunits are modified during glycation and even some are truncated during aging. All these facts indicate the importance of arginine residues in α-crystallin. Scope of review In this review, we will emphasize the recent in vitro and in vivo findings related to congenital cataract causing arginine mutations in α-crystallin. Major conclusions Congenital cataract causing arginine mutations alters the structure and decreases the chaperone function of α-crystallin. These mutations also affect the lens morphology and phenotypes. Interestingly, non-natural arginine mutations (generated for mimicking the glycation and truncation environment) improve the chaperone function of α-crystallin which may play an important role in maintaining the eye lens transparency during aging. General significance The neutralization of positive charge on the guanidino group of arginine residues is not always detrimental to the functionality of α-crystallin. PMID:26080000

  10. Arginine: Its pKa value revisited

    Science.gov (United States)

    Fitch, Carolyn A; Platzer, Gerald; Okon, Mark; Garcia-Moreno E, Bertrand; McIntosh, Lawrence P

    2015-01-01

    Using complementary approaches of potentiometry and NMR spectroscopy, we have determined that the equilibrium acid dissociation constant (pKa value) of the arginine guanidinium group is 13.8 ± 0.1. This is substantially higher than that of ∼12 often used in structure-based electrostatics calculations and cited in biochemistry textbooks. The revised intrinsic pKa value helps explains why arginine side chains in proteins are always predominantly charged, even at pH values as great as 10. The high pKa value also reinforces the observation that arginine side chains are invariably protonated under physiological conditions of near neutral pH. This occurs even when the guanidinium moiety is buried in a hydrophobic micro-environment, such as that inside a protein or a lipid membrane, thought to be incompatible with the presence of a charged group. PMID:25808204

  11. The effect of recombinant erythropoietin on plasma brain derived neurotrophic factor levels in patients with affective disorders

    DEFF Research Database (Denmark)

    Vinberg, Maj; Miskowiak, Kamilla; Hoejman, Pernille;

    2015-01-01

    UNLABELLED: The study aims to investigate the effect of repeated infusions of recombinant erythropoietin (EPO) on plasma brain derived neurotrophic factor (BDNF) levels in patients with affective disorders. In total, 83 patients were recruited: 40 currently depressed patients with treatment-resistant...... depression (TRD) (Hamilton Depression Rating Scale-17 items (HDRS-17) score >17) (study 1) and 43 patients with bipolar disorder (BD) in partial remission (HDRS-17 and Young Mania Rating Scale (YMRS) ≤ 14) (study 2). In both studies, patients were randomised to receive eight weekly EPO (Eprex; 40,000 IU) or...

  12. Changes in Dietary Fat Content Rapidly Alters the Mouse Plasma Coagulation Profile without Affecting Relative Transcript Levels of Coagulation Factors

    Science.gov (United States)

    van Diepen, Janna A.; Verhoef, Daniël; Voshol, Peter J.; Reitsma, Pieter H.; van Vlijmen, Bart J. M.

    2015-01-01

    Background Obesity is associated with a hypercoagulable state and increased risk for thrombotic cardiovascular events. Objective Establish the onset and reversibility of the hypercoagulable state during the development and regression of nutritionally-induced obesity in mice, and its relation to transcriptional changes and clearance rates of coagulation factors as well as its relation to changes in metabolic and inflammatory parameters. Methods Male C57BL/6J mice were fed a low fat (10% kcal as fat; LFD) or high fat diet (45% kcal as fat; HFD) for 2, 4, 8 or 16 weeks. To study the effects of weight loss, mice were fed the HFD for 16 weeks and switched to the LFD for 1, 2 or 4 weeks. For each time point analyses of plasma and hepatic mRNA levels of coagulation factors were performed after overnight fasting, as well as measurements of circulating metabolic and inflammatory parameters. Furthermore, in vivo clearance rates of human factor (F) VII, FVIII and FIX proteins were determined after 2 weeks of HFD-feeding. Results HFD feeding gradually increased the body and liver weight, which was accompanied by a significant increase in plasma glucose levels from 8 weeks onwards, while insulin levels were affected after 16 weeks. Besides a transient rise in cytokine levels at 2 weeks after starting the HFD, no significant effect on inflammation markers was present. Increased plasma levels of fibrinogen, FII, FVII, FVIII, FIX, FXI and FXII were observed in mice on a HFD for 2 weeks, which in general persisted throughout the 16 weeks of HFD-feeding. Interestingly, with the exception of FXI the effects on plasma coagulation levels were not paralleled by changes in relative transcript levels in the liver, nor by decreased clearance rates. Switching from HFD to LFD reversed the HFD-induced procoagulant shift in plasma, again not coinciding with transcriptional modulation. Conclusions Changes in dietary fat content rapidly alter the mouse plasma coagulation profile, thereby

  13. Arginine: Its pKa value revisited

    OpenAIRE

    Fitch, Carolyn A.; Platzer, Gerald; Okon, Mark; Garcia-Moreno E, Bertrand; McIntosh, Lawrence P.

    2015-01-01

    Using complementary approaches of potentiometry and NMR spectroscopy, we have determined that the equilibrium acid dissociation constant (pKa value) of the arginine guanidinium group is 13.8 ± 0.1. This is substantially higher than that of ∼12 often used in structure-based electrostatics calculations and cited in biochemistry textbooks. The revised intrinsic pKa value helps explains why arginine side chains in proteins are always predominantly charged, even at pH values as great as 10. The hi...

  14. Kiwifruit consumption favourably affects plasma lipids in a randomised controlled trial in hypercholesterolaemic men.

    Science.gov (United States)

    Gammon, Cheryl S; Kruger, Rozanne; Minihane, Anne M; Conlon, Cathryn A; von Hurst, Pamela R; Stonehouse, Welma

    2013-06-28

    The unique composition of green kiwifruit has the potential to benefit CVD risk. The aim of the present study was to investigate the effect of consuming two green kiwifruits daily in conjunction with a healthy diet on plasma lipids and other metabolic markers and to examine response according to APOE genotype in hypercholesterolaemic men. After undergoing a 4-week healthy diet, eighty-five hypercholesterolaemic men (LDL-cholesterol (LDL-C) > 3.0 mmol/l and TAG < 3 mmol/l) completed an 8-week randomised controlled cross-over study of two 4-week intervention sequences of two green kiwifruits per d plus healthy diet (intervention) or healthy diet alone (control). Anthropometric measures, blood pressure (BP) and fasting blood samples (plasma lipids, serum apoA1 and apoB, insulin, glucose, high-sensitivity C-reactive protein (hs-CRP)) were taken at baseline, and at 4 and 8 weeks. After the kiwifruit intervention, plasma HDL-cholesterol (HDL-C) concentrations were significantly higher (mean difference 0.04; 95% CI 0.01, 0.07 mmol/l; P = 0.004) and the total cholesterol (TC):HDL-C ratio was significantly lower (mean difference 20.5; 95% CI 20.24, 20.05 mmol/l; P = 0.002) compared with the control. In carriers of the APOE4 allele, TAG decreased significantly (mean difference -0.18; 95% CI -0.34, -0.02 mol/l; P = 0.03) with kiwifruit compared with control. There were no significant differences between the two interventions for plasma TC, LDL-C, insulin, glucose, hs-CRP and BP. The small but significant increase in HDL-C and decrease in TC:HDL-C ratio and TAG (in APOE4 carriers) suggest that the regular inclusion of green kiwifruit as part of a healthy diet may be beneficial in improving the lipid profiles of men with high cholesterol. PMID:23151354

  15. Radial thermal diffusivity of toroidal plasma affected by resonant magnetic perturbations

    International Nuclear Information System (INIS)

    We investigate how the radial thermal diffusivity of an axisymmetric toroidal plasma is modified by effect of resonant magnetic perturbations (RMPs), using a drift kinetic simulation code for calculating the thermal diffusivity in the perturbed region. The perturbed region is assumed to be generated on and around the resonance surfaces, and is wedged in between the regular closed magnetic surfaces. It has been found that the radial thermal diffusivity χr in the perturbed region is represented as χr = χr(0) {1 + c r parallel2>}. Here r parallel2>1/2 is the strength of the RMPs in the radial directions, means the flux surface average defined by the unperturbed (i.e., original) magnetic field, χr(0) is the neoclassical thermal diffusivity, and c is a positive coefficient. In this paper, dependence of the coefficient c on parameters of the toroidal plasma is studied in results given by the δ f simulation code solving the drift kinetic equation under an assumption of zero electric field. We find that the dependence of c is given as c ∝ ωb/νeff m in the low collisionality regime νeff b, where νeff is the effective collision frequency, ωb is the bounce frequency and m is the particle mass. In case of νeff > ωb, the thermal diffusivity χr evaluated by the simulations becomes close to the neoclassical thermal diffusivity χr(0). (author)

  16. Glycosaminoglycans affect the interaction of human plasma kallikrein with plasminogen, factor XII and inhibitors

    Directory of Open Access Journals (Sweden)

    Gozzo A.J.

    2003-01-01

    Full Text Available Human plasma kallikrein, a serine proteinase, plays a key role in intrinsic blood clotting, in the kallikrein-kinin system, and in fibrinolysis. The proteolytic enzymes involved in these processes are usually controlled by specific inhibitors and may be influenced by several factors including glycosaminoglycans, as recently demonstrated by our group. The aim of the present study was to investigate the effect of glycosaminoglycans (30 to 250 µg/ml on kallikrein activity on plasminogen and factor XII and on the inhibition of kallikrein by the plasma proteins C1-inhibitor and antithrombin. Almost all available glycosaminoglycans (heparin, heparan sulfate, bovine and tuna dermatan sulfate, chondroitin 4- and 6-sulfates reduced (1.2 to 3.0 times the catalytic efficiency of kallikrein (in a nanomolar range on the hydrolysis of plasminogen (0.3 to 1.8 µM and increased (1.9 to 7.7 times the enzyme efficiency in factor XII (0.1 to 10 µM activation. On the other hand, heparin, heparan sulfate, and bovine and tuna dermatan sulfate improved (1.2 to 3.4 times kallikrein inhibition by antithrombin (1.4 µM, while chondroitin 4- and 6-sulfates reduced it (1.3 times. Heparin and heparan sulfate increased (1.4 times the enzyme inhibition by the C1-inhibitor (150 nM.

  17. Aflatoxin B1 induced upregulation of protein arginine methyltransferase 5 in human cell lines.

    Science.gov (United States)

    Ghufran, Md Sajid; Ghosh, Krishna; Kanade, Santosh R

    2016-09-01

    The exposure of naturally occurring mycotoxins affects human health and play a vital role in cancer initiation and progression. Aflatoxin B1 is a difuranocoumarin mycotoxin, classified as a group I carcinogen. The present study was conducted to assess the effect of aflatoxin B1 on epigenetic regulatory proteins. The protein arginine methyltransferase 5 expression was induced upon aflatoxin B1 treatment in a dose and time dependent manner. Further global arginine methylation was also increased in the same manner. This is the first report showing the induction of epigenetic regulatory protein, protein arginine methyltransferase 5 upon aflatoxin B1 treatment. Further study is required to establish the detailed pathway of PRMT5 induction. PMID:27242039

  18. Does the plasma composition affect the long term evolution of relativistic jets?

    CERN Document Server

    Scheck, L; Martí, J M; Gómez, J L; Müller, E

    2002-01-01

    We study the influence of the matter content of extragalactic jets on their morphology, dynamics and emission properties. For this purpose we consider jets of extremely different compositions including pure leptonic and baryonic plasmas. Our work is based on two-dimensional relativistic hydrodynamic simulations of the long-term evolution of powerful extragalactic jets propagating into a homogeneous environment. The equation of state used in the simulations accounts for an arbitrary mixture of electrons, protons and electron-positron pairs. Using the hydrodynamic models we have also computed synthetic radio maps and the thermal Bremsstrahlung X-ray emission from their cavities. Although there is a difference of about three orders of magnitude in the temperatures of the cavities inflated by the simulated jets, we find that both the morphology and the dynamic behaviour are almost independent on the assumed composition of the jets. Their evolution proceeds in two distinct epochs. During the first one multidimensi...

  19. Fish oil affects blood pressure and the plasma lipid profile in healthy Danish infants

    DEFF Research Database (Denmark)

    Damsgaard, C.T.; Schack-Nielsen, L.; Michaelsen, K.F.; Fruekilde, Maj-Britt; Hels, O.; Lauritzen, L.

    2006-01-01

    Animal and epidemiologic studies indicate that early nutrition has lasting effects on metabolism and cardiovascular disease risk. In adults, (n-3) long-chain PUFA (LCPUFA) from fish oils improve blood pressure, the lipid profile, and possibly cardiovascular disease mortality. This randomized trial...... is the first to investigate the effects of fish oil on blood pressure and the lipid profile in infancy. Healthy term 9-mo old infants In 83) were randomly assigned to 5 mL fish oil daily or no fish oil for 3 mo and to 2 different milk types. Before and after the intervention, blood pressure was...... measured with an oscillometric device, and blood was sampled for analysis of erythrocyte fatty acid composition and the plasma lipid profile. This paper examines the effects of the fish oil supplement, with adjustment for the effects of the milk intervention when relevant. The fish oil intervention...

  20. Modulators of arginine metabolism support cancer immunosurveillance

    Directory of Open Access Journals (Sweden)

    Freschi Massimo

    2009-01-01

    Full Text Available Abstract Background Tumor-associated accrual of myeloid derived suppressor cells (MDSC in the blood, lymphoid organs and tumor tissues may lead to perturbation of the arginine metabolism and impairment of the endogenous antitumor immunity. The objective of this study was to evaluate whether accumulation of MDSC occurred in Th2 prone BALB/c and Th1 biased C57BL/6 mice bearing the C26GM colon carcinoma and RMA T lymphoma, respectively, and to investigate whether N(G nitro-L-arginine methyl ester (L-NAME and sildenafil, both modulators of the arginine metabolism, restored antitumor immunity. Results We report here that MDSC accumulate in the spleen and blood of mice irrespective of the mouse and tumor model used. Treatment of tumor-bearing mice with either the phosphodiesterase-5 inhibitor sildenafil or the nitric-oxide synthase (NOS inhibitor L-NAME significantly restrained tumor growth and expanded the tumor-specific immune response. Conclusion Our data emphasize the role of MDSC in modulating the endogenous tumor-specific immune response and underline the anti-neoplastic therapeutic potential of arginine metabolism modulators.

  1. Lysine and arginine requirements of Salminus brasiliensis

    Directory of Open Access Journals (Sweden)

    Jony Koji Dairiki

    2013-08-01

    Full Text Available The objective of this work was to determine the dietary lysine (DL and dietary arginine (DA requirements of dourado (Salminus brasiliensis, through dose-response trials using the amino acid profiles of whole carcasses as a reference. Two experiments were carried out in a completely randomized design (n=4. In the first experiment, groups of 12 feed-conditioned dourado juveniles (11.4±0.2 g were stocked in 60 L cages placed in 300 L plastic indoor tanks in a closed circulation system. Fish were fed for 60 days on diets containing 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 % dietary lysine. In the second experiment, dourado juveniles (27.0±0.8 g were fed for 60 days on semipurified diets containing arginine at 1.0, 1.5, 2.0, 2.5 or 3.0%, in similar conditions to those of the first experiment. Optimal DL requirements, as determined by broken-line analysis method for final weight, weight gain and specific growth rate, were 2.15% DL or 5% lysine in dietary protein, and 1.48% DA or 3.43% arginine in dietary protein. The best feed conversion ratio is attained with 2.5% DL or 5.8% lysine in dietary protein and 1.4% DA or 3.25% arginine in dietary protein.

  2. Effects of acute supplementation of L-arginine and nitrate on endurance and sprint performance in elite athletes.

    Science.gov (United States)

    Sandbakk, Silvana Bucher; Sandbakk, Øyvind; Peacock, Oliver; James, Philip; Welde, Boye; Stokes, Keith; Böhlke, Nikolai; Tjønna, Arnt Erik

    2015-08-01

    This study examined the effects of acute supplementation with L-arginine and nitrate on running economy, endurance and sprint performance in endurance-trained athletes. In a randomised cross-over, double-blinded design we compared the effects of combined supplementation with 6 g L-arginine and 614 mg nitrate against 614 mg nitrate alone and placebo in nine male elite cross-country skiers (age 18 ± 0 years, VO2max 69.3 ± 5.8 ml ⋅ min(-1) ⋅ kg(-1)). After a 48-hour standardisation of nutrition and exercise the athletes were tested for plasma nitrate and nitrite concentrations, blood pressure, submaximal running economy at 10 km ⋅ h(-1) and 14 km ⋅ h(-1) at 1% incline and 180 m as well as 5-km time-trial running performances. Plasma nitrite concentration following L-arginine + nitrate supplementation (319 ± 54 nmol ⋅ L(-1)) did not differ from nitrate alone (328 ± 107 nmol ⋅ L(-1)), and both were higher than placebo (149 ± 64 nmol ⋅ L(-1), p nitrite concentrations indicate greater nitric oxide availability both following acute supplementation of L-arginine + nitrate and with nitrate alone compared to placebo, but no additional effect was revealed when L-arginine was added to nitrate. Still, there were no effects of supplementation on exercise economy or endurance running performance in endurance-trained cross-country skiers. PMID:25445632

  3. Platelet concentration in platelet-rich plasma affects tenocyte behavior in vitro.

    Science.gov (United States)

    Giusti, Ilaria; D'Ascenzo, Sandra; Mancò, Annalisa; Di Stefano, Gabriella; Di Francesco, Marianna; Rughetti, Anna; Dal Mas, Antonella; Properzi, Gianfranco; Calvisi, Vittorio; Dolo, Vincenza

    2014-01-01

    Since tendon injuries and tendinopathy are a growing problem, sometimes requiring surgery, new strategies that improve conservative therapies are needed. Platelet-rich plasma (PRP) seems to be a good candidate by virtue of its high content of growth factors, most of which are involved in tendon healing. This study aimed to evaluate if different concentrations of platelets in PRP have different effects on the biological features of normal human tenocytes that are usually required during tendon healing. The different platelet concentrations tested (up to 5 × 10(6) plt/µL) stimulated differently tenocytes behavior; intermediate concentrations (0.5 × 10(6), 1 × 10(6) plt/µL) strongly induced all tested processes (proliferation, migration, collagen, and MMPs production) if compared to untreated cells; on the contrary, the highest concentration had inhibitory effects on proliferation and strongly reduced migration abilities and overall collagen production but, at the same time, induced increasing MMP production, which could be counterproductive because excessive proteolysis could impair tendon mechanical stability. Thus, these in vitro data strongly suggest the need for a compromise between extremely high and low platelet concentrations to obtain an optimal global effect when inducing in vivo tendon healing. PMID:25147809

  4. Platelet Concentration in Platelet-Rich Plasma Affects Tenocyte Behavior In Vitro

    Directory of Open Access Journals (Sweden)

    Ilaria Giusti

    2014-01-01

    Full Text Available Since tendon injuries and tendinopathy are a growing problem, sometimes requiring surgery, new strategies that improve conservative therapies are needed. Platelet-rich plasma (PRP seems to be a good candidate by virtue of its high content of growth factors, most of which are involved in tendon healing. This study aimed to evaluate if different concentrations of platelets in PRP have different effects on the biological features of normal human tenocytes that are usually required during tendon healing. The different platelet concentrations tested (up to 5 × 106 plt/µL stimulated differently tenocytes behavior; intermediate concentrations (0.5 × 106, 1 × 106 plt/µL strongly induced all tested processes (proliferation, migration, collagen, and MMPs production if compared to untreated cells; on the contrary, the highest concentration had inhibitory effects on proliferation and strongly reduced migration abilities and overall collagen production but, at the same time, induced increasing MMP production, which could be counterproductive because excessive proteolysis could impair tendon mechanical stability. Thus, these in vitro data strongly suggest the need for a compromise between extremely high and low platelet concentrations to obtain an optimal global effect when inducing in vivo tendon healing.

  5. Dual role of arginine metabolism in establishing pathogenesis.

    Science.gov (United States)

    Gogoi, Mayuri; Datey, Akshay; Wilson, Keith T; Chakravortty, Dipshikha

    2016-02-01

    Arginine is an integral part of host defense when invading pathogens are encountered. The arginine metabolite nitric oxide (NO) confers antimicrobial properties, whereas the metabolite ornithine is utilized for polyamine synthesis. Polyamines are crucial to tissue repair and anti-inflammatory responses. iNOS/arginase balance can determine Th1/Th2 response. Furthermore, the host arginine pool and its metabolites are utilized as energy sources by various pathogens. Apart from its role as an immune modulator, recent studies have also highlighted the therapeutic effects of arginine. This article sheds light upon the roles of arginine metabolism during pathological conditions and its therapeutic potential. PMID:26610300

  6. Copeptin, a surrogate marker for arginine vasopressin, is associated with declining glomerular filtration in patients with diabetes mellitus (ZODIAC-33)

    NARCIS (Netherlands)

    Boertien, W. E.; Riphagen, I. J.; Drion, I.; Alkhalaf, A.; Bakker, S. J. L.; Groenier, K. H.; Struck, J.; de Jong, P. E.; Bilo, H. J. G.; Kleefstra, N.; Gansevoort, R. T.

    2013-01-01

    Arginine vasopressin (AVP), the hormone important for maintaining fluid balance, has been shown to cause kidney damage in rodent models of diabetes. We investigated the potential role of AVP in the natural course of kidney function decline in diabetes in an epidemiological study. Plasma copeptin, a

  7. Urinary and metabolic clearances of arginine vasopressin in normal subjects

    International Nuclear Information System (INIS)

    Synthetic arginine vasopressin (AVP) was infused into 11 hydrated normal subjects at five different infusion rates ranging from 10 to 350 μU kg-1 min-1. Each infusion rate was continued for 1 h, and urinary determinations were made on the 30- to 60-min specimens during which time there was no further rise in plasma AVP. Urinary AVP concentrations (μU/ml) and excretion rates (μU/min) increased linearly with increasing infusion rates, and the concentration of AVP in urine increased 120 times more rapid than plasma. Urinary and metabolic clearances of AVP also increased linearly with the maximum urinary clearance being 60.6% of the creatinine clearance. The total metabolic clearance of AVP (including urinary clearance) was 17.8 times that of the urinary clearance of AVP alone. These data clarify the relationships between plasma and urinary AVP in normal hydrated subjects during AVP infusion under steady-state conditions and emphasize the potential advantage of measuring urinary AVP as a monitor of endogenous AVP secretion. AVP was measured by radioimmunoassay

  8. Nanosecond electric pulses affect a plant-specific kinesin at the plasma membrane.

    Science.gov (United States)

    Kühn, Sebastian; Liu, Qiong; Eing, Christian; Frey, Wolfgang; Nick, Peter

    2013-12-01

    Electric pulses with high field strength and durations in the nanosecond range (nsPEFs) are of considerable interest for biotechnological and medical applications. However, their actual cellular site of action is still under debate--due to their extremely short rise times, nsPEFs are thought to act mainly in the cell interior rather than at the plasma membrane. On the other hand, nsPEFs can induce membrane permeability. We have revisited this issue using plant cells as a model. By mapping the cellular responses to nsPEFs of different field strength and duration in the tobacco BY-2 cell line, we could define a treatment that does not impinge on short-term viability, such that the physiological responses to the treatment can be followed. We observe, for these conditions, a mild disintegration of the cytoskeleton, impaired membrane localization of the PIN1 auxin-efflux transporter and a delayed premitotic nuclear positioning followed by a transient mitotic arrest. To address the target site of nsPEFs, we made use of the plant-specific KCH kinesin, which can assume two different states with different localization (either near the nucleus or at the cell membrane) driving different cellular functions. We show that nsPEFs reduce cell expansion in nontransformed cells but promote expansion in a line overexpressing KCH. Since cell elongation and cell widening are linked to the KCH localized at the cell membrane, the inverted response in the KCH overexpressor provides evidence for a direct action of nsPEFs, also at the cell membrane. PMID:24062185

  9. Chemical modification of arginine residues in the lactose repressor

    International Nuclear Information System (INIS)

    The lactose repressor protein was chemically modified with 2,3-butanedione and phenylglyoxal. Arginine reaction was quantitated by either amino aced analysis or incorporation of 14C-labeled phenylglyoxal. Inducer binding activity was unaffected by the modification of arginine residues, while both operator and nonspecific DNA binding activities were diminished, although to differing degrees. The correlation of the decrease in DNA binding activities with the modification of ∼ 1-2 equiv of arginine per monomer suggests increased reactivity of a functionally essential residue(s). For both reagents, operator DNA binding activity was protected by the presence of calf thymus DNA, and the extent of reaction with phenylglyoxal was simultaneously diminished. This protection presumably results from steric restriction of reagent access to an arginine(s) that is (are) essential for DNA binding interactions. These experiments suggest that there is (are) an essential reactive arginine(s) critical for repressor binding to DNA

  10. Numerical simulation of dispersive Alfvén wave turbulence in auroral plasmas affecting the Earth's communications

    International Nuclear Information System (INIS)

    This paper presents the numerical simulation of the model equation governing the nonlinear dynamics of dispersive Alfvén waves (DAWs) in low-β plasmas. When the nonlinearity arises due to the ponderomotive force and Joule heating-driven density perturbations, the model equation turns out to be a modified nonlinear Schrödinger (MNLS) equation. The nonlinear MNLS is used to investigate the evolution of a finite-amplitude localized initial perturbation. The initial perturbation is of the form of a sinusoidal pulse on a DAW having a Gaussian wavefront. The localized structures of DAWs with sidebands are obtained. Also, we have studied the power spectra of magnetic fluctuations with different scaling laws. These turbulent structures may be responsible for particle acceleration in the aurora region and may affect the Earth's communication.

  11. The Metabolic Conversion of Arginine in the Rumen Wall and its Importance in Ruminant Nitrogen Metabolism

    International Nuclear Information System (INIS)

    The functions of arginase and urease of the rumen wall were investigated in vitro and in vivo. Surviving ruminal mucosae of cattle were incubated for four hours. 14C-arginine-HCl, uniformly labelled, was added to the serosal side at a concentration of 10 pmol/mi. About 25% of the added arginine was used during the incubation by the ruminal tissue. In comparison with controls an increased amount of 14C-omithine, urea, and ammonia were formed in the mucosa and appeared on both sides. The increase was due to arginase and urease functions. It was estimated that about 50% of the urea formed by arginine breakdown were present at the mucosa side, mainly in the form of ammonia. Of the omithine simultaneously formed, 85% remained on the serosa side. Remarkable individual variations of omithine and urea formation were found from animal to animal. The in-vivo experiments were performed using goats with catheters placed in the right ruminal artery and vein. We injected 90 μCi of 14C-arginine into the ruminal artery. When 80 g of soluble starch were added to the rumen the activity and concentration of ornithine increased in the ruminal venous blood showing an arterial-venous difference. The radioactivity of urea in blood taken from the ruminal vein and the carotid artery did not show any difference. When starch was omitted from the rumen a comparable difference of omithine concentration was not found. It is assumed that the enzymes arginase and urease of the rumen wall are involved in nitrogen recycling processes. Blood arginine may be hydrolysed in the rumen wall forming urea and ornithine. Urea formed by arginine breakdown may be split to CO2 and ammonia. The experiments produced evidence that the ammonia formed preferably enters the rumen content. The nitrogen transfer through the rumen wall may be affected by varying activities of arginase. (author)

  12. Dietary fat affects plasma prolactin in female F344 rats under conditions of ether stress.

    Science.gov (United States)

    Bosland, M C; Bunnik, G S; Wilbrink, B; de Bie, B T; Floor, B

    1994-01-01

    The influence of amount and type of dietary fat on circulating concentrations of prolactin and estradiol-17 beta in female F344 rats from which blood was sampled by decapitation under ether anesthesia was compared with that in rats from which blood was collected without anesthesia. The animals were fed isonutrient (adjusted for differences in energy density) semipurified diets containing 5% or 20% (by weight) sunflower seed oil or lard. Blood was sampled by decapitation with or without standardized ether anesthesia during the afternoon of proestrus-estrus or the morning of metestrus-diestrus, as determined by examination of vaginal smears. Plasma hormone concentrations were measured by radioimmunoassay. Prolactin levels were lower during proestrus-estrus in rats fed a low-fat diet than in animals fed a high-fat diet, statistically independent of the type of dietary fat, but only when blood was sampled by decapitation under ether anesthesia [p = 0.0384, 2-way analysis of variance (ANOVA)]. No such difference was found in rats decapitated without anesthesia. This effect of amount of dietary fat on prolactin in proestrus-estrus animals anesthetized with ether was predominantly present in animals fed polyunsaturated fat (p rats fed saturated fat diets. During metestrus-diestrus, prolactin levels were significantly lower in animals fed a high-saturated fat diet than in those fed low-saturated fat, low-unsaturated fat, or high-unsaturated fat diets, independent of the blood sampling conditions (p conversion efficiency was lower in animals fed low-fat diets than in those fed high-fat diets. This study confirms the hypothesis that effects of dietary fat, particularly polyunsaturated fat, on circulating prolactin occur only during (ether) stress. Because stress is a frequent and normal phenomenon, this observation implies that the mammary glands of animals with a high dietary intake of polyunsaturated fat are frequently exposed to higher circulating prolactin concentrations

  13. Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

    Directory of Open Access Journals (Sweden)

    Johanna M Walz

    Full Text Available Vascular endothelial growth factor-A (VEGF-A is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD, cannula (butterfly vs. neonatal, type of centrifuge (swing-out vs. fixed-angle, time before and after centrifugation, filling level (completely filled vs. half-filled tubes and analyzing method (ELISA vs. multiplex bead array. Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

  14. Noncanonical Myo9b-RhoGAP Accelerates RhoA GTP Hydrolysis by a Dual-Arginine-Finger Mechanism.

    Science.gov (United States)

    Yi, Fengshuang; Kong, Ruirui; Ren, Jinqi; Zhu, Li; Lou, Jizhong; Wu, Jane Y; Feng, Wei

    2016-07-31

    The GTP hydrolysis activities of Rho GTPases are stimulated by GTPase-activating proteins (GAPs), which contain a RhoGAP domain equipped with a characteristic arginine finger and an auxiliary asparagine for catalysis. However, the auxiliary asparagine is missing in the RhoGAP domain of Myo9b (Myo9b-RhoGAP), a unique motorized RhoGAP that specifically targets RhoA for controlling cell motility. Here, we determined the structure of Myo9b-RhoGAP in complex with GDP-bound RhoA and magnesium fluoride. Unexpectedly, Myo9b-RhoGAP contains two arginine fingers at its catalytic site. The first arginine finger resembles the one within the canonical RhoGAP domains and inserts into the nucleotide-binding pocket of RhoA, whereas the second arginine finger anchors the Switch I loop of RhoA and interacts with the nucleotide, stabilizing the transition state of GTP hydrolysis and compensating for the lack of the asparagine. Mutating either of the two arginine fingers impaired the catalytic activity of Myo9b-RhoGAP and affected the Myo9b-mediated cell migration. Our data indicate that Myo9b-RhoGAP accelerates RhoA GTP hydrolysis by a previously unknown dual-arginine-finger mechanism, which may be shared by other noncanonical RhoGAP domains lacking the auxiliary asparagine. PMID:27363609

  15. Arginine, scurvy and Cartier's "tree of life"

    OpenAIRE

    Durzan Don J

    2009-01-01

    Abstract Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compoun...

  16. Protective Effects of Arginine on Saccharomyces cerevisiae Against Ethanol Stress

    Science.gov (United States)

    Cheng, Yanfei; Du, Zhaoli; Zhu, Hui; Guo, Xuena; He, Xiuping

    2016-01-01

    Yeast cells are challenged by various environmental stresses in the process of industrial fermentation. As the currently main organism for bio-ethanol production, Saccharomyces cerevisiae suffers from ethanol stress. Some amino acids have been reported to be related to yeast tolerance to stresses. Here the relationship between arginine and yeast response to ethanol stress was investigated. Marked inhibitions of ethanol on cell growth, expression of genes involved in arginine biosynthesis and intracellular accumulation of arginine were observed. Furthermore, extracellular addition of arginine can abate the ethanol damage largely. To further confirm the protective effects of arginine on yeast cells, yeast strains with different levels of arginine content were constructed by overexpression of ARG4 involved in arginine biosynthesis or CAR1 encoding arginase. Intracellular arginine was increased by 18.9% or 13.1% respectively by overexpression of ARG4 or disruption of CAR1, which enhanced yeast tolerance to ethanol stress. Moreover, a 41.1% decrease of intracellular arginine was observed in CAR1 overexpressing strain, which made yeast cells keenly sensitive to ethanol. Further investigations indicated that arginine protected yeast cells from ethanol damage by maintaining the integrity of cell wall and cytoplasma membrane, stabilizing the morphology and function of organellae due to low ROS generation. PMID:27507154

  17. L-arginine inhibits isoproterenol-induced cardiac hypertrophy through nitric oxide and polyamine pathways.

    Science.gov (United States)

    Lin, Yan; Wang, Li-Na; Xi, Yu-Hui; Li, Hong-Zhu; Xiao, Feng-Gang; Zhao, Ya-Jun; Tian, Ye; Yang, Bao-Feng; Xu, Chang-Qing

    2008-08-01

    Polyamines (putrescine, spermidine and spermine) are essential for cell growth and differentiation. Nitric oxide exhibits antihypertrophic functions and inhibits cardiac remodelling. However, the metabolism of polyamines and the potential interactions with nitric oxide in cardiac hypertrophy remain unclear. We randomly divided Wistar rats into four treatment groups: controls, isoproterenol (ISO), ISO and L-arginine, and L-arginine. Isoproterenol (5 mg/kg/day, subcutaneously) and/or L-arginine (800 mg/kg/day, intraperitoneally) was administered once daily for 7 days. The expression of atrial natriuretic peptide mRNA was determined by reverse transcription-polymerase chain reaction, and fibrogenesis of heart was assessed by Van Gieson staining. Polyamines were measured with high-performance liquid chromatography, and plasma nitric oxide content and lactate dehydrogenase (LDH) activity were determined with a spectrophotometer. The expression levels of ornithine decarboxylase, spermidine/spermine N1-acetyltransferase (SSAT), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) were analysed by Western blot. Heart-to-body weight ratio, left ventricle-to-body weight ratio, atrial natriuretic peptide mRNA expression, collagen fibres and LDH activity were elevated, both ornithine decarboxylase and SSAT proteins were up-regulated, and total polyamines were increased in the group treated with ISO. Additionally, the expression of iNOS was up-regulated, eNOS was down-regulated, and nitric oxide levels were low. Notably, cotreatment with L-arginine reversed most of these changes except for SSAT expression,which was further up-regulated. We propose that increased polyamines and decreased nitric oxide are involved in cardiac hypertrophy induced by ISO and suggest that L-arginine pre-treatment can attenuate cardiac hypertrophy through the regulation of key enzymes of the polyamine and nitric oxide pathways. PMID:18816294

  18. Ex-vivo changes in amino acid concentrations from blood stored at room temperature or on ice: implications for arginine and taurine measurements

    Directory of Open Access Journals (Sweden)

    McNeil Yvette R

    2009-11-01

    Full Text Available Abstract Background Determination of the plasma concentrations of arginine and other amino acids is important for understanding pathophysiology, immunopathology and nutritional supplementation in human disease. Delays in processing of blood samples cause a change in amino acid concentrations, but this has not been precisely quantified. We aimed to describe the concentration time profile of twenty-two amino acids in blood from healthy volunteers, stored at room temperature or on ice. Methods Venous blood was taken from six healthy volunteers and stored at room temperature or in an ice slurry. Plasma was separated at six time points over 24 hours and amino acid levels were determined by high-performance liquid chromatography. Results Median plasma arginine concentrations decreased rapidly at room temperature, with a 6% decrease at 30 minutes, 25% decrease at 2 hours and 43% decrease at 24 hours. Plasma ornithine increased exponentially over the same period. Plasma arginine was stable in blood stored on ice, with a Conclusion Plasma arginine concentrations in stored blood fall rapidly at room temperature, but remain stable on ice for at least 24 hours. Blood samples taken for the determination of plasma amino acid concentrations either should be placed immediately on ice or processed within 30 minutes of collection.

  19. Effects of Alterations of Plasma Free Fatty Acid Levels on Pancreatic Glucagon Secretion in Man

    Science.gov (United States)

    Gerich, John E.; Langlois, Maurice; Schneider, Victor; Karam, John H.; Noacco, Claudio

    1974-01-01

    The present investigation was undertaken to ascertain whether alterations in plasma free fatty acids (FFA) affect pancreatic glucagon secretion in man since FFA have been reported to influence pancreatic alpha cell function in other species. Elevation of plasma FFA from a mean (±SE) basal level of 0.478±0.036 mM to 0.712±0.055 mM after heparin administration caused plasma glucagon levels to fall approximately 50%, from a basal value of 122±15 pg/ml to 59±14 pg/ml (P < 0.001). Lowering of plasma FFA from a basal level of 0.520±0.046 mM to 0.252±0.041 mM after nicotinic acid administration raised plasma glucagon from a basal level of 113±18 pg/ml to 168±12 pg/ml (P < 0.005). Infusion of glucose elevated plasma glucose levels to the same degree that heparin raised plasma FFA levels. This resulted in suppression of plasma glucagon despite the fact that plasma FFA levels also were suppressed. Glucagon responses to arginine were diminished after elevation of plasma FFA (P < 0.01) and during infusion of glucose (P < 0.01). Diminution of plasma FFA by nicotinic acid did not augment glucagon responses to arginine. These results thus demonstrate that rather small alterations in plasma FFA within the physiologic range have a significant effect on glucagon secretion in man. Although the effects of glucose appear to predominate over those of FFA, alterations in plasma FFA may nevertheless exert an important physiologic influence over human pancreatic alpha cell function, especially in the postabsorptive state. PMID:4825225

  20. Arginine biosynthesis in Thermotoga maritima: characterization of the arginine-sensitive N-acetyl-L-glutamate kinase.

    Science.gov (United States)

    Fernández-Murga, M Leonor; Gil-Ortiz, Fernando; Llácer, José L; Rubio, Vicente

    2004-09-01

    To help clarify the control of arginine synthesis in Thermotoga maritima, the putative gene (argB) for N-acetyl-L-glutamate kinase (NAGK) from this microorganism was cloned and overexpressed, and the resulting protein was purified and shown to be a highly thermostable and specific NAGK that is potently and selectively inhibited by arginine. Therefore, NAGK is in T. maritima the feedback control point of arginine synthesis, a process that in this organism involves acetyl group recycling and appears not to involve classical acetylglutamate synthase. The inhibition of NAGK by arginine was found to be pH independent and to depend sigmoidally on the concentration of arginine, with a Hill coefficient (N) of approximately 4, and the 50% inhibitory arginine concentration (I0.5) was shown to increase with temperature, approaching above 65 degrees C the I0.50 observed at 37 degrees C with the mesophilic NAGK of Pseudomonas aeruginosa (the best-studied arginine-inhibitable NAGK). At 75 degrees C, the inhibition by arginine of T. maritima NAGK was due to a large increase in the Km for acetylglutamate triggered by the inhibitor, but at 37 degrees C arginine also substantially decreased the Vmax of the enzyme. The NAGKs of T. maritima and P. aeruginosa behaved in gel filtration as hexamers, justifying the sigmoidicity and high Hill coefficient of arginine inhibition, and arginine or the substrates failed to disaggregate these enzymes. In contrast, Escherichia coli NAGK is not inhibited by arginine and is dimeric, and thus the hexameric architecture may be an important determinant of arginine sensitivity. Potential thermostability determinants of T. maritima NAGK are also discussed. PMID:15342584

  1. [Antioxidant effects of L-arginine in the rat heart in experimental rhabdomyolysis].

    Science.gov (United States)

    Filimonenko, V P; Nikitchenko, I V; Kaliman, P A

    2009-01-01

    The glycerol administration in a dose of 1 ml of 50% water solution/100 g b. w. was found to cause considerable accumulation of the total heme in the rat blood serum that is accompanied by an increase of TBA-reactive products and protein carbonyl derivates contents and by changes of protein level. Heme entering in the heart tissue is observed in the first hours after glycerol injection. The breaches of heart antioxidant-prooxidant balance are noted in twenty-four hours: TBA-reactive products and protein carbonyl derivates accumulation, heme oxygenase and catalase activation, superoxide dismutase activity lowering and reduction of glutathione content elevation. Pretreatment by L-arginine (0.5 h before glycerol administration) almost did not affect the blood serum changes caused by glycerol injection. However in the rat heart L-arginine administration prevents from TBA-reactive products and protein carbonyl derivates accumulation and the breaches of superoxide dismutase and catalase activities. Besides L-arginine causes the ealier heme oxygenase induction. Possible mechanisms of L-arginine protective action in the rat heart under experimental rhabdomyolysis are discussed. PMID:19877424

  2. Effect of an hyperbaric nitrogen narcotic ambience on arginine and citrulline levels, the precursor and co-product of nitric oxide, in rat striatum

    Directory of Open Access Journals (Sweden)

    Vallée Nicolas

    2011-07-01

    Full Text Available Abstract Previous studies performed in the laboratory have shown that nitrogen narcosis induces a decrease in striatal glutamate and dopamine levels. Although we stimulated the N-methyl-D-aspartate (NMDA receptor, an important glutamate receptor required for motor and locomotor activity managed by the striatum, and demonstrated that the receptor was effective when exposed to nitrogen at 3MPa, it was not possible to return the striatal glutamate level to its base values. We conclude that it was the striatopetal neurons of the glutamatergic pathways that were mainly affected in this hyperbaric syndrome, without understanding the principal reasons. Hence we sought to establish what happens in the vicinity of the plasma membrane, downstream the NMDA-Receptor, and we used the hypothesis that there could be neuronal nitric oxide synthase (nNOS disturbances. A microdialysis study was performed in rat striatum in order to analyse levels of citrulline, the NO co-product, and arginine, the NO precursor. Those both NO metabolites were detectable with an HPLC coupled to a fluorimetric detector. Exposure to pressurized nitrogen induced a reduction in citrulline (-18.9% and arginine (-10.4% levels. Under the control normobaric conditions, the striatal NMDA infusion enhanced the citrulline level (+85.6%, whereas under 3 MPa of nitrogen, the same NMDA infusion did not change the citrulline level which remains equivalent to that of the baseline. The level of arginine increased (+45.7% under normobaric conditions but a decrease occurred in pressurized nitrogen (-51.6%. Retrodialysis with Saclofen and KCl in the prefrontal cortex under normobaric conditions led to an increase in striatal levels of citrulline (+30.5% and a decrease in arginine levels (-67.4%. There was no significant difference when nitrogen at 3MPa was added. To conclude, the synthesis of citrulline/NO is reduced in nitrogen narcosis while it seems possible to activate it artificially by infusion

  3. Spectrophotometric Determination of Arginine in Grape Juice Using 8-Hydroquinoline

    Institute of Scientific and Technical Information of China (English)

    WANG Hua; LIANG Xin-hong; ZHAO Rui-xiang; FENG Li-dan; LI Hua

    2008-01-01

    Arginine in grape juice can be metabolized by wine yeasts and malolactic bacteria to precursors of ethyl carbamate, known as carcinogen. The aim of this study was to develop a simple, fast, and accurate method for determining arginine in grape juice with Sakaguchi reaction by separating arginine with strong cation-exchange resins. Parameters were optimized including the concentrations of 8-hydroquinoline and sodium hydrobromite. The color stability lasted for 4 min, which is sufficient to finish the measurement. The method is simple, reproducible and accurate, and can be applied for quick measurement of arginine in grape juice to take necessary measures for controlling the level of ethyl carbamate.

  4. Arginine Biosynthesis in Thermotoga maritima: Characterization of the Arginine-Sensitive N-Acetyl-l-Glutamate Kinase

    OpenAIRE

    Fernández-Murga, M. Leonor; Gil-Ortiz, Fernando; Llácer, José L.; Rubio, Vicente

    2004-01-01

    To help clarify the control of arginine synthesis in Thermotoga maritima, the putative gene (argB) for N-acetyl-l-glutamate kinase (NAGK) from this microorganism was cloned and overexpressed, and the resulting protein was purified and shown to be a highly thermostable and specific NAGK that is potently and selectively inhibited by arginine. Therefore, NAGK is in T. maritima the feedback control point of arginine synthesis, a process that in this organism involves acetyl group recycling and ap...

  5. Effect of dietary lysine restriction and arginine supplementation in two patients with pyridoxine-dependent epilepsy.

    Science.gov (United States)

    Yuzyuk, Tatiana; Thomas, Amanda; Viau, Krista; Liu, Aiping; De Biase, Irene; Botto, Lorenzo D; Pasquali, Marzia; Longo, Nicola

    2016-07-01

    Pyridoxine-Dependent Epilepsy (PDE) is a recessive disorder caused by deficiency of α-aminoadipic semialdehyde dehydrogenase in the catabolic pathway of lysine. It is characterized by intractable seizures controlled by the administration of pharmacological doses of vitamin B6. Despite seizure control with pyridoxine, intellectual disability and developmental delays are still observed in some patients with PDE, likely due to the accumulation of toxic intermediates in the lysine catabolic pathway: alpha-aminoadipic semialdehyde (AASA), delta-1-piperideine-6-carboxylate (P6C), and pipecolic acid. Here we evaluate biochemical and clinical parameters in two PDE patients treated with a lysine-restricted diet and arginine supplementation (100-150mg/kg), aimed at reducing the levels of PDE biomarkers. Lysine restriction resulted in decreased accumulation of PDE biomarkers and improved development. Plasma lysine but not plasma arginine, directly correlated with plasma levels of AASA-P6C (p<0.001, r(2)=0.640) and pipecolic acid (p<0.01, r(2)=0.484). In addition, plasma threonine strongly correlated with the levels of AASA-P6C (p<0.0001, r(2)=0.732) and pipecolic acid (p<0.005, r(2)=0.527), suggesting extreme sensitivity of threonine catabolism to pyridoxine availability. Our results further support the use of dietary therapies in combination with pyridoxine for the treatment of PDE. PMID:27324284

  6. Possible involvement of a plasmid in arginine auxotrophic mutation of Streptomyces kasugaensis.

    OpenAIRE

    Nakano, M M; Ozawa, K; Ogawara, H

    1980-01-01

    Streptomyces kasugaensis gave arginine auxotrophic mutants at high frequency, The coupled loss and reappearance of plasmid deoxyribonucleic acid with arginine auxotrophy suggested that the insertion of the plasmid into chromosomal deoxyribonucleic acid caused the arginine auxotrophy.

  7. Postnatal changes of plasma amino acids in suckling pigs.

    Science.gov (United States)

    Flynn, N E; Knabe, D A; Mallick, B K; Wu, G

    2000-09-01

    Amino acids, ammonia, urea, orotate, and nitrate plus nitrite (stable oxidation products of nitric oxide) were determined in plasma of 1- to 21-d-old suckling pigs. Jugular venous blood samples were obtained from pigs at 1, 3, 7, 14, and 21 d of age for analysis of plasma amino acids and metabolites by HPLC and enzymatic methods. Plasma concentrations of arginine and its immediate precursors (citrulline and ornithine) decreased (P Plasma concentrations of glutamine declined (P Plasma concentrations of branched-chain amino acids, threonine, and alanine decreased (P changes (P > 0.05) in plasma concentrations of other amino acids. Plasma concentrations of ammonia increased (P nitric oxide synthesis, our results of the decreased plasma concentrations of arginine and nitrate plus nitrite, as well as the increased plasma ammonia concentration, indicate a hitherto unrecognized deficiency of arginine in 7- to 21-d-old suckling pigs. Arginine is an essential amino acid for piglets and has a great potential to enhance neonatal growth; therefore, further studies are necessary to elucidate the mechanism responsible for arginine deficiency in sow-reared piglets and to identify hormonal and metabolic means for improving neonatal arginine nutrition and growth. PMID:10985412

  8. Structures of Bacterial Biosynthetic Arginine Decarboxylases

    Energy Technology Data Exchange (ETDEWEB)

    F Forouhar; S Lew; J Seetharaman; R Xiao; T Acton; G Montelione; L Tong

    2011-12-31

    Biosynthetic arginine decarboxylase (ADC; also known as SpeA) plays an important role in the biosynthesis of polyamines from arginine in bacteria and plants. SpeA is a pyridoxal-5'-phosphate (PLP)-dependent enzyme and shares weak sequence homology with several other PLP-dependent decarboxylases. Here, the crystal structure of PLP-bound SpeA from Campylobacter jejuni is reported at 3.0 {angstrom} resolution and that of Escherichia coli SpeA in complex with a sulfate ion is reported at 3.1 {angstrom} resolution. The structure of the SpeA monomer contains two large domains, an N-terminal TIM-barrel domain followed by a {beta}-sandwich domain, as well as two smaller helical domains. The TIM-barrel and {beta}-sandwich domains share structural homology with several other PLP-dependent decarboxylases, even though the sequence conservation among these enzymes is less than 25%. A similar tetramer is observed for both C. jejuni and E. coli SpeA, composed of two dimers of tightly associated monomers. The active site of SpeA is located at the interface of this dimer and is formed by residues from the TIM-barrel domain of one monomer and a highly conserved loop in the {beta}-sandwich domain of the other monomer. The PLP cofactor is recognized by hydrogen-bonding, {pi}-stacking and van der Waals interactions.

  9. Arginine specific aminopeptidase from Lactobacillus brevis

    Directory of Open Access Journals (Sweden)

    Arya Nandan

    2010-12-01

    Full Text Available The proteolytic system of lactic acid bacteria contribute to the development of flavor during the ripening of cheese through the generation of short peptides and free amino acids, which directly or indirectly act as flavor precursors. Newly isolated lactic acid bacteria (LAB as well as those procured from culture collection centers were screened for the production of various substrate specific aminopeptidases. Among all the strains screened, L. brevis (NRRL B-1836 was found to produce quantifiable amount of intracellular arginine specific aminopeptidase (EC 3.4.11.6. The productivity of arginine aminopeptidase in 5 L fermentor was 36 IU/L/h. The Luedeking and Piret model was tested for intracellular production of aminopeptidase and the data seemed to fit well, as the correlation coefficient was 0.9964 for MRS. The αAP and βAP was 0.4865 and 0.0046, respectively in MRS medium indicating that the yield was predominantly depended on growth. The culture produced lactic acid and also tolerated pH 2.0-3.0 and 0.3-0.5% bile salts, the most important probiotic features.

  10. Novel Vasoregulatory Aspects of Hereditary Angioedema: the Role of Arginine Vasopressin, Adrenomedullin and Endothelin-1.

    Science.gov (United States)

    Kajdácsi, Erika; Jani, Péter K; Csuka, Dorottya; Varga, Lilian; Prohászka, Zoltán; Farkas, Henriette; Cervenak, László

    2016-02-01

    The elevation of bradykinin (BK) level during attacks of hereditary angioedema due to C1-Inhibitor deficiency (C1-INH-HAE) is well known. We previously demonstrated that endothelin-1 (ET-1) level also increases during C1-INH-HAE attacks. Although BK and ET-1 are both potent vasoactive peptides, the vasoregulatory aspect of the pathomechanism of C1-INH-HAE has not yet been investigated. Hence we studied the levels of vasoactive peptides in controls and in C1-INH-HAE patients, as well as evaluated their changes during C1-INH-HAE attacks. The levels of arginine vasopressin (AVP), adrenomedullin (ADM) and ET-1 were measured in the plasma of 100 C1-INH-HAE patients in inter-attack periods and of 111 control subjects, using BRAHMS Kryptor technologies. In 18 of the 100 C1-INH-HAE patients, the levels of vasoactive peptides were compared in blood samples obtained during attacks, or in inter-attack periods. AVP, ADM and ET-1 levels were similar in inter-attack samples from C1-INH-HAE patients and in the samples of controls, although cardiovascular risk has an effect on the levels of vasoactive peptides in both groups. The levels of all three vasoactive peptides increased during C1-INH-HAE attacks. Moreover, the levels of ET-1 and ADM as well as their changes during attacks were significantly correlated. This study demonstrated that vascular regulation by vasoactive peptides is affected during C1-INH-HAE attacks. Our results suggest that the cooperation of several vasoactive peptides may be necessary to counterbalance the actions of excess BK, and to terminate the attacks. This may reveal a novel pathophysiological aspect of C1-INH-HAE. PMID:26873707

  11. Arginine Deiminase Resistance in Melanoma Cells Is Associated with Metabolic Reprogramming, Glucose Dependence and Glutamine Addiction

    OpenAIRE

    Long, Yan; Tsai, Wen-Bin; Wangpaichitr, Medhi; Tsukamoto, Takashi; Savaraj, Niramol; Feun, Lynn G.; Kuo, Macus Tien

    2013-01-01

    Many malignant human tumors, including melanomas are auxotrophic for arginine due to reduced expression of argininosuccinate synthetase1 (ASS1), the rate-limiting enzyme for arginine biosynthesis. Pegylated arginine deiminase (ADI-PEG20), which degrades extracellular arginine resulting in arginine deprivation, has shown favorable results in clinical trials for treating arginine-auxotrophic tumors. Drug resistance is the major obstacle for effective ADI-PEG20 usage. To elucidate mechanisms of ...

  12. On the mechanism of arginine requirement for adenovirus synthesis

    International Nuclear Information System (INIS)

    The effects of arginine deprivation on the synthesis and processing of viral proteins and the assembly of incomplete and complete virions were studied during infection with human adenovirus type 2. Arginine deprivation greatly reduced the synthesis of all viral proteins, particularly the precursor to core protein VII. The inhibition was completely reversible by the addition of arginine to the medium. Arginine deprivation between 7 and 20 hours post-infection inhibited the processing of PVII to VII, suggesting that PVII is not cleaved autocatalytically. The assembly of incomplete virions was sensitive to arginine deprivation only prior to 20 hours, while the assembly of complete virions was dependent on the continuous presence of arginine. This observation supports the hypothesis that incomplete virions are precursors of complete virions. The experiments on the PVII-specific endoprotease activity showed that arginine deprivation caused only slight reduction in the in vitro activity, although no activity was observed in vivo. The present results lead to the hypothesis that arginine deficiency inhibits the synthesis of a functional protein essential for virion maturation, other than the synthesis of processing of PVII. (author)

  13. Polyamine formation by arginine decarboxylase as a transducer of hormonal, environmental and stress stimuli in higher plants

    Science.gov (United States)

    Galston, A. W.; Flores, H. E.; Kaur-Sawhney, R.

    1982-01-01

    Recent evidence implicates polyamines including putrescine in the regulation of such diverse plant processes as cell division, embryogenesis and senescence. We find that the enzyme arginine decarboxylase, which controls the rate of putrescine formation in some plant systems, is activated by light acting through P(r) phytochrome as a receptor, by the plant hormone gibberellic acid, by osmotic shock and by other stress stimuli. We therefore propose arginine decarboxylase as a possible transducer of the various initially received tropistic stimuli in plants. The putrescine formed could act by affecting cytoskeletal components.

  14. Effects of chronic oral L-arginine administration on the L-arginine/NO pathway in patients with peripheral arterial occlusive disease or coronary artery disease: L-Arginine prevents renal loss of nitrite, the major NO reservoir.

    Science.gov (United States)

    Schneider, Jessica Y; Rothmann, Sabine; Schröder, Frank; Langen, Jennifer; Lücke, Thomas; Mariotti, François; Huneau, Jean François; Frölich, Jürgen C; Tsikas, Dimitrios

    2015-09-01

    Despite saturation of nitric oxide (NO) synthase (NOS) by its substrate L-arginine (Arg), oral and intravenous supplementation of Arg may enhance NO synthesis, a phenomenon known as "The L-arginine paradox". Yet, Arg is not only a source of NO, but is also a source for guanidine-methylated (N (G)) arginine derivatives which are all inhibitors of NOS activity. Therefore, Arg supplementation may not always result in enhanced NO synthesis. Concomitant synthesis of N (G)-monomethyl arginine (MMA), N (G),N (G)-dimethylarginine (asymmetric dimethylarginine, ADMA) and N (G),N (G´)-dimethylarginine (symmetric dimethylarginine, SDMA) from supplemented Arg may outweigh and even outbalance the positive effects of Arg on NO. Another possible, yet little investigated effect of Arg supplementation may be alteration of renal function, notably the influence on the excretion of nitrite in the urine. Nitrite is the autoxidation product of NO and the major reservoir of NO in the circulation. Nitrite and Arg are reabsorbed in the proximal tubule of the nephron and this reabsorption is coupled, at least in part, to the renal carbonic anhydrase (CA) activity. In the present placebo-controlled studies, we investigated the effect of chronic oral Arg supplementation of 10 g/day for 3 or 6 months in patients suffering from peripheral arterial occlusive disease (PAOD) or coronary artery disease (CAD) on the urinary excretion of nitrite relative to nitrate. We determined the urinary nitrate-to-nitrite molar ratio (UNOxR), which is a measure of nitrite-dependent renal CA activity before and after oral intake of Arg or placebo by the patients. The UNOxR was also determined in 6 children who underwent the Arg test, i.e., intravenous infusion of Arg (0.5 g Arg/kg bodyweight) for 30 min. Arg was well tolerated by the patients of the three studies. Oral Arg supplementation increased Arg (plasma and urine) and ADMA (urine) concentrations. No appreciable changes were seen in NO (in PAOD and CAD) and

  15. Anti-aging effects of l-arginine

    Directory of Open Access Journals (Sweden)

    Mohamed Z. Gad

    2010-07-01

    Full Text Available l-Arginine is one of the most metabolically versatile amino acids. In addition to its role in the synthesis of nitric oxide, l-arginine serves as a precursor for the synthesis of polyamines, proline, glutamate, creatine, agmatine and urea. Several human and experimental animal studies have indicated that exogenous l-arginine intake has multiple beneficial pharmacological effects when taken in doses larger than normal dietary consumption. Such effects include reduction in the risk of vascular and heart diseases, reduction in erectile dysfunction, improvement in immune response and inhibition of gastric hyperacidity. This review summarises several positive studies and personal experiences of l-arginine. The demonstrated anti-aging benefits of l-arginine show greater potential than any pharmaceutical or nutraceutical agent ever previously discovered.

  16. Interactions between genetic variants of folate metabolism genes and lifestyle affect plasma homocysteine concentrations in the Boston Puerto Rican Population

    Science.gov (United States)

    Results of studies investigating relationships between lifestyle factors and elevated plasma homocysteine (Hcy), an independent risk factor for cardiovascular disease, are conflicting. The objective of this study was to investigate genetic and lifestyle factors and their interactions on plasma Hcy c...

  17. Lipid-based nutrient supplements do not affect efavirenz but lower plasma nevirapine concentrations in Ethiopian adult HIV patients

    DEFF Research Database (Denmark)

    Abdissa, A; Olsen, Mette Frahm; Yilma, D; Tesfaye, M; Girma, T; Christiansen, M; Hagen, C M; Wiesner, L; Castel, S; Aseffa, A; McIlleron, H; Pedersen, C; Friis, Henrik; Andersen, A B

    2015-01-01

    OBJECTIVES: Lipid-based nutrient supplements (LNSs) are increasingly used in HIV programmes in resource-limited settings. However, the possible effects of LNSs on the plasma concentrations of antiretroviral drugs have not been assessed. Here, we aimed to assess the effects of LNSs on plasma...

  18. [Effect of L-arginine on pro- and antioxidant status of the rat vessels and lungs in experimental rhabdomyolysis].

    Science.gov (United States)

    Fylymonenko, V P; Nikitchenko, I V; Kaliman, P A

    2009-01-01

    The glycerol administration was found to cause accumulation of the total heme in rat blood serum, vessels and lungs that are accompanied by increase of TBA-reactive products and protein carbonyl derivates contents. A decrease of superoxide dismutase activity and an increase of reduced glutathione in lung were observed. Heme entering the vessels and lungs is accompanied by elevation in heme oxygenase activity. Pretreatment by L-arginine (0.5 h before glycerol administration) didn't affect blood serum and vessels changes caused by glycerol injection. However, in lungs, L-arginine prevents TBA-reactive products and protein carbonyl derivates accumulation, the decrease ofsuperoxide dismutase activity and causes the ealier heme oxygenase induction. Prooxidant effects of heme in tissues studied and possible mechanisms of L-arginine protective action in lung under experimental rhabdomyolysis are discussed. PMID:20095386

  19. Protective effect of L-arginine against necrosis and apoptosis induced by experimental ischemic and reperfusion in rat liver

    International Nuclear Information System (INIS)

    To study the effect of L-arginine on apoptosis and necrosis induced by 1-h ischemia followed by 3-h reperfusion. Adult Wistar rats underwent 60 min of partial liver ischemia followed by 3-h reperfusion. Eighteen Wistar rats were divided into sham-operated control group (1) ( n = 6), ischemia and reperfusion (I/R) group (0.9 % saline (5 ml/kg, orally) for 7 days) (2) ( n 6), and L-arginine-treated group (10 mg/kg body weight daily orally for 7 days before inducing ischemia-reperfusion maneuver) (3) ( n = 6). Apoptotic and necrotic hepatocytes, nitric oxide levels in hepatocytes, Bcl-2 mRNA, and Bcl-2 protein were measured. Liver injury was assessed by plasma alanine transaminases (ALT), aspartate transaminases (AST), liver histopathology, and electron microscopy. An ischemic and reperfusion hepatocellular injury occurred as was indicated by increased serum ALT, AST, histopathology, and electron microscopy. Apoptosis and necrosis associated marker gene Bcl-2 mRNA and protein expression were decreased in I/R group. Pretreatment with L-arginine significantly decreased serum ALT and AST level and apoptotic and necrotic cells after 1 h ischemia followed by 3 h of reperfusion. Nitric oxide production in hepatocytes was increased twofold by L-arginine treatment when compared with I/R group. Histopathology and transmission electron microscopy (TEM) studies showed markedly diminished hepatocellular injury in L-arginine-pretreated rats during the hepatic I/R. Thus, it may be concluded that L-arginine afforded significant protection from necrosis and apoptosis in I/R injury by upregulated Bcl-2 gene and nitric oxide production. (author)

  20. Safety, efficacy and physiological actions of a lysine-free, arginine-rich formula to treat glutaryl-CoA dehydrogenase deficiency: focus on cerebral amino acid influx.

    Science.gov (United States)

    Strauss, Kevin A; Brumbaugh, Joan; Duffy, Alana; Wardley, Bridget; Robinson, Donna; Hendrickson, Christine; Tortorelli, Silvia; Moser, Ann B; Puffenberger, Erik G; Rider, Nicholas L; Morton, D Holmes

    2011-01-01

    Striatal degeneration from glutaryl-CoA dehydrogenase deficiency (glutaric aciduria type 1, GA1) is associated with cerebral formation and entrapment of glutaryl-CoA and its derivatives that depend on cerebral lysine influx. In 2006 we designed a lysine-free study formula enriched with arginine to selectively block lysine transport across cerebral endothelia and thereby limit glutaryl-CoA production by brain. Between 2006 and present, we treated twelve consecutive children with study formula (LYSx group) while holding all other treatment practices constant. Clinical and biochemical outcomes were compared to 25 GA1 patients (PROx group) treated between 1995 and 2005 with natural protein restriction (dietary lysine/arginine ratio of 1.7±0.3 mg:mg). We used published kinetic parameters of the y+and LAT1 blood-brain barrier transporters to model the influx of amino acids into the brain. Arginine fortification to achieve a mean dietary lysine/arginine ratio of 0.7±0.2 mg:mg was neuroprotective. All 12 LYSx patients are physically and neurologically healthy after 28 aggregate patient-years of follow up (current ages 28±21 months) and there were no adverse events related to formula use. This represents a 36% reduction of neurological risk (95% confidence interval 14-52%, p=0.018) that we can directly attribute to altered amino acid intake. During the first year of life, 20% lower lysine intake and two-fold higher arginine intake by LYSx patients were associated with 50% lower plasma lysine, 3-fold lower plasma lysine/arginine concentration ratio, 42% lower mean calculated cerebral lysine influx, 54% higher calculated cerebral arginine influx, 15-26% higher calculated cerebral influx of several anaplerotic precursors (isoleucine, threonine, methionine, and leucine), 50% less 3-hydroxyglutarate excretion, and a 3-fold lower hospitalization rate (0.8 versus 2.3 hospitalizations per patient per year). The relationship between arginine fortification and plasma lysine

  1. Effect of psychological stress on the L-arginine-nitric oxide pathway and semen quality

    Directory of Open Access Journals (Sweden)

    S. Eskiocak

    2006-05-01

    Full Text Available It has been reported that mental stress causes abnormality of spermiogram parameters. We investigated the effect of psychological stress on the L-arginine-nitric oxide (NO pathway. Semen samples were collected from 29 healthy fourth semester medical students just before (stress and 3 months after (non-stress the final examinations. Psychological stress was measured by the State Anxiety Inventory questionnaire. After standard semen analysis, arginase activity and NO concentration were measured spectrophotometrically in the seminal plasma. Measurements were made in duplicate. During the stress period, sperm concentration (41.28 ± 3.70 vs 77.62 ± 7.13 x 10(6/mL, rapid progressive motility of spermatozoa (8.79 ± 1.66 vs 20.86 ± 1.63% and seminal plasma arginase activity (0.12 ± 0.01 vs 0.22 ± 0.01 U/mL were significantly lower than in the non-stress situation, whereas seminal plasma NO (17.28 ± 0.56 vs 10.02 ± 0.49 µmol/L was higher compared to the non-stress period (P < 0.001 for all. During stress there was a negative correlation between NO concentration and sperm concentration, the percentage of rapid progressive motility and arginase activity (r = -0.622, P < 0.01; r = -0.425, P < 0.05 and r = -0.445, P < 0.05, respectively. These results indicate that psychological stress causes an increase of NO level and a decrease of arginase activity in the L-arginine-NO pathway. Furthermore, poor sperm quality may be due to excessive production of NO under psychological stress. In the light of these results, we suggest that the arginine-NO pathway, together with arginase and NO synthase, are involved in semen quality under stress conditions.

  2. Fish oil in combination with high or low intakes of linoleic acid lowers plasma triacylglycerols but does not affect other cardiovascular risk markers in healthy men

    DEFF Research Database (Denmark)

    Damsgaard, Camilla T.; Frøkiær, Hanne; Andersen, Anders D.; Lauritzen, Lotte

    2008-01-01

    , fibrinogen, C-reactive protein, interleukin-6, vascular cell adhesion molecule-1, P-selectin, oxidized LDL, cluster of differentiation antigen 40 ligand (CD40L), adiponectin, or fasting or postprandial BP or HR after adjustment for body weight changes. In conclusion, neither fish oil supplementation nor the...... intake in the S/B groups than in the R/K groups. Diet, (n-3) LCPUFA in peripheral blood mononuclear cells, blood pressure (BP), heart rate (HR), and plasma CVD risk markers were measured before and after the intervention. FO lowered fasting plasma triacylglycerol (TAG) (P <0.001) by 51% and 19% in the FO......+R/K-group and FO+S/B-group, respectively, which was also reflected in postprandial TAG measured after the intervention (P <0.01). Although a fat x FO interaction was found for monocyte chemoattractant protein-1, neither the FO nor fat intervention affected fasting plasma cholesterol, glucose, insulin...

  3. Toxoplasma gondii lacks the enzymes required for de novo arginine biosynthesis and arginine starvation triggers cyst formation.

    Science.gov (United States)

    Fox, Barbara A; Gigley, Jason P; Bzik, David J

    2004-03-01

    Two separate carbamoyl phosphate synthetase activities are required for the de novo synthesis of pyrimidines and arginine in most eukaryotes. Toxoplasma gondii is novel in possessing a single carbamoyl phosphate synthetase II gene that corresponds to a glutamine-dependent form required for pyrimidine biosynthesis. We therefore examined arginine acquisition in T. gondii to determine whether the single carbamoyl phosphate synthetase II activity could provide both pyrimidine and arginine biosynthesis. We found that arginine deprivation efficiently blocks the replication of intracellular T. gondii, yet has little effect on long-term parasite viability. Addition of citrulline, but not ornithine, rescues the growth defect observed in the absence of exogenous arginine. This rescue with citrulline is ablated when parasites are cultured in a human citrullinemia fibroblast cell line that is deficient in argininosuccinate synthetase activity. These results reveal the absence of genes and activities of the arginine biosynthetic pathway and demonstrate that T. gondii is an arginine auxotroph. Arginine starvation was also found to efficiently trigger differentiation of replicative tachyzoites into bradyzoites contained within stable cyst-like structures. These same parasites expressing bradyzoite antigens can be efficiently switched back to rapidly proliferating tachyzoites several weeks after arginine starvation. We hypothesise that the absence of gene activities that are essential for the biosynthesis of arginine from carbamoyl phosphate confers a selective advantage by increasing bradyzoite switching during the host response to T. gondii infection. These findings are consistent with a model of host-parasite evolution that allowed host control of bradyzoite induction by trading off virulence for increased transmission. PMID:15003493

  4. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    International Nuclear Information System (INIS)

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T4 were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T4 as compared to controls. There were significant negative correlations between NO and both ADMA (r2 = 0.84) and free T4 (r2 = 0.95) in overt hypothyroid group while significant positive correlation (r2 = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females

  5. Plasma membrane lipid–protein interactions affect signaling processes in sterol-biosynthesis mutants in Arabidopsis thaliana

    OpenAIRE

    Zauber, Henrik; Burgos, Asdrubal; Garapati, Prashanth; Schulze, Waltraud X.

    2014-01-01

    The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein-protein and protein-lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane...

  6. The Effect of Recombinant Erythropoietin on Plasma Brain Derived Neurotrophic Factor Levels in Patients with Affective Disorders: A Randomised Controlled Study

    OpenAIRE

    Maj Vinberg; Kamilla Miskowiak; Pernille Hoejman; Maria Pedersen; Lars Vedel Kessing

    2015-01-01

    The study aims to investigate the effect of repeated infusions of recombinant erythropoietin (EPO) on plasma brain derived neurotrophic factor (BDNF) levels in patients with affective disorders. In total, 83 patients were recruited: 40 currently depressed patients with treatment-resistant depression (TRD) (Hamilton Depression Rating Scale-17 items (HDRS-17) score >17) (study 1) and 43 patients with bipolar disorder (BD) in partial remission (HDRS-17 and Young Mania Rating Scale (YMRS) ≤ 14) (...

  7. Comparative analysis of twin-arginine (Tat)-dependent protein secretion of a heterologous model protein (GFP) in three different Gram-positive bacteria

    NARCIS (Netherlands)

    Meissner, Daniel; Vollstedt, Angela; van Dijl, Jan Maarten; Freudl, Roland

    2007-01-01

    In contrast to the general protein secretion (Sec) system, the twin-arginine translocation (Tat) export pathway allows the translocation of proteins across the bacterial plasma membrane in a fully folded conformation. Due to this feature, the Tat pathway provides an attractive alternative to the sec

  8. Arginine-aromatic interactions and their effects on arginine-induced solubilization of aromatic solutes and suppression of protein aggregation

    KAUST Repository

    Shah, Dhawal

    2011-09-21

    We examine the interaction of aromatic residues of proteins with arginine, an additive commonly used to suppress protein aggregation, using experiments and molecular dynamics simulations. An aromatic-rich peptide, FFYTP (a segment of insulin), and lysozyme and insulin are used as model systems. Mass spectrometry shows that arginine increases the solubility of FFYTP by binding to the peptide, with the simulations revealing the predominant association of arginine to be with the aromatic residues. The calculations further show a positive preferential interaction coefficient, Γ XP, contrary to conventional thinking that positive Γ XP\\'s indicate aggregation rather than suppression of aggregation. Simulations with lysozyme and insulin also show arginine\\'s preference for aromatic residues, in addition to acidic residues. We use these observations and earlier results reported by us and others to discuss the possible implications of arginine\\'s interactions with aromatic residues on the solubilization of aromatic moieties and proteins. Our results also highlight the fact that explanations based purely on Γ XP, which measures average affinity of an additive to a protein, could obscure or misinterpret the underlying molecular mechanisms behind additive-induced suppression of protein aggregation. © 2011 American Institute of Chemical Engineers (AIChE).

  9. Glutamate, Ornithine, Arginine, Proline, and Polyamine Metabolic Interactions: The Pathway Is Regulated at the Post-Transcriptional Level

    Science.gov (United States)

    Majumdar, Rajtilak; Barchi, Boubker; Turlapati, Swathi A.; Gagne, Maegan; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash C.

    2016-01-01

    The metabolism of glutamate into ornithine, arginine, proline, and polyamines is a major network of nitrogen-metabolizing pathways in plants, which also produces intermediates like nitric oxide, and γ-aminobutyric acid (GABA) that play critical roles in plant development and stress. While the accumulations of intermediates and the products of this network depend primarily on nitrogen assimilation, the overall regulation of the interacting sub-pathways is not well understood. We tested the hypothesis that diversion of ornithine into polyamine biosynthesis (by transgenic approach) not only plays a role in regulating its own biosynthesis from glutamate but also affects arginine and proline biosynthesis. Using two high putrescine producing lines of Arabidopsis thaliana (containing a transgenic mouse ornithine decarboxylase gene), we studied the: (1) effects of exogenous supply of carbon and nitrogen on polyamines and pools of soluble amino acids; and, (2) expression of genes encoding key enzymes in the interactive pathways of arginine, proline and GABA biosynthesis as well as the catabolism of polyamines. Our findings suggest that: (1) the overall conversion of glutamate to arginine and polyamines is enhanced by increased utilization of ornithine for polyamine biosynthesis by the transgene product; (2) proline and arginine biosynthesis are regulated independently of polyamines and GABA biosynthesis; (3) the expression of most genes (28 that were studied) that encode enzymes of the interacting sub-pathways of arginine and GABA biosynthesis does not change even though overall biosynthesis of Orn from glutamate is increased several fold; and (4) increased polyamine biosynthesis results in increased assimilation of both nitrogen and carbon by the cells. PMID:26909083

  10. Proteomic analysis of plasma from cows affected with milk fever using two-dimensional differential in-gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Xia, C; Zhang, H Y; Wu, L; Xu, C; Zheng, J S; Yan, Y J; Yang, L J; Shu, S

    2012-10-01

    Milk fever is an important metabolic disorder of dairy cows after calving, and is characterized by hypocalcemia, tetany, lateral recumbency, and eventual coma. To date, there have been many reports about the pathogenesis and pathophysiology of milk fever, but the plasma protein profile in milk fever has not been reported. The aim of our study was to investigate novel pathophysiological changes in the plasma proteome of cows affected with milk fever. Plasma samples were collected from eight Holstein cows with milk fever (T), and eight control Holstein cows without milk fever (C), at an intensive Holstein dairy farm in Heilongjiang province, China. Samples were analyzed by fluorescence two-dimensional (2D) differential in-gel electrophoresis (DIGE), followed by in-gel digestion, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for peptide mass fingerprinting of selected protein spots. Eight of the 23 differential protein spots in the plasma of T and C cows were isolated and identified by 2D-DIGE and MALDI-TOF-MS. The protein spots represented five unique proteins, and had significant alterations in spot volume as determined by DeCyder differential in-gel analysis (DIA) software. The upregulated proteins were identified as serpin peptidase inhibitor (angiotensin), which regulates blood pressure and maintains fluid and electrolyte homeostasis, and endopin 2B which is involved in neural regulation. The downregulated proteins were serum albumin, which acts as a transport protein, fibrinogen beta chain which is involved in blood coagulation, and IgG heavy-chain C-region (IgG-C(H)) which participates in the immune response. In conclusion, we were able to use proteomic technologies to identify several novel plasma proteins in cows affected with milk fever. These findings may reveal new pathophysiological changes that occur in cows with milk fever. PMID:22119234

  11. Ageing and long-term smoking affects KL-6 levels in the lung, induced sputum and plasma

    Directory of Open Access Journals (Sweden)

    Horimasu Yasushi

    2011-05-01

    Full Text Available Abstract Background KL-6 is a high-molecular-weight glycoprotein classified as a human MUC1 mucin. It was hypothesized that KL-6 could be detectable in the circulating blood and especially in airway secretions in lung diseases associated with mucus production such as chronic obstructive pulmonary disease (COPD. Additional aims of this study were to investigate whether the levels of KL-6 in plasma and sputum are related to ageing and smoking history. Methods The concentrations of KL-6 in plasma and induced sputum supernatants from young and/or middle aged/elderly non-smokers, smokers and patients with COPD were assayed by ELISA (n = 201. The subjects were classified into five groups according to age, smoking status and presence of COPD. In addition, KL-6 expression in control and diseased lung i.e. samples from patients with COPD (n = 28, were analyzed by immunohistochemistry and digital image analysis. Results The plasma levels of KL-6 increased with age both in non-smokers and smokers. Among middle aged/elderly subjects, plasma KL-6 levels in all smokers regardless of COPD were significantly higher than in non-smokers, whereas sputum levels of KL-6 were significantly higher in COPD compared not only to non-smokers but also to smokers. KL-6 was more prominently expressed in the bronchiolar/alveolar epithelium in COPD than in the control lungs. Plasma and sputum KL-6 levels correlated inversely with obstruction and positively with smoking history and ageing. The linear multiple regression analysis confirmed that age and cigarette smoking had independent effects on plasma KL-6. Conclusions KL-6 increases with ageing and chronic smoking history, but prospective studies will be needed to elucidate the significance of KL-6 in chronic airway diseases.

  12. A lignan complex isolated from flaxseed does not affect plasma lipid concentrations or antioxidant capacity in healthy postmenopausal women

    DEFF Research Database (Denmark)

    Hallund, Jesper; Ravn-Haren, Gitte; Bügel, S.;

    2006-01-01

    A lignan complex rich in the plant lignan secoisolariciresinol diglucoside (SDG) was isolated from flaxseed. SDG is metabolized by the colonic microflora to the mammalian lignans enterodiol (END) and enterolactone (ENL), and was hypothesized to reduce plasma lipid concentrations and improve...... antioxidant capacity, The aim of this study was to investigate the effects of a lignan complex, providing 500 mg/d of SDG, on serum concentration and urinary excretion of ENL, plasma lipids, serum lipoprotein oxidation resistance, and markers of antioxidant capacity. Healthy postmenopausal women (n=22...

  13. Measurement of arginine metabolites: regulators of nitric oxide metabolism.

    Science.gov (United States)

    Augustine, Molly S; Rogers, Lynette K

    2013-01-01

    Arginine is the substrate for nitric oxide synthases (NOS), and arginine availability regulates the production of nitric oxide. Through the activity of methyltransferases, arginine can be methylated to form monomethylarginine (NMMA), asymmetrical dimethylarginine (ADMA), and symmetrical dimethylarginine (SDMA). NMMA and ADMA directly inhibit NOS, whereas SDMA inhibits the cellular import of arginine through the cationic amino acid transporter. Increased levels of methylarginine compounds have been associated with many diseases including atherosclerosis, renal failure, pulmonary hypertension, and preeclampsia. Previous HPLC methods to measure these molecules rely on derivatization with ortho-phthalaldehyde, which is unstable and requires immediate pre- or post-column reactions. We have identified a new fluorometric agent that is stable for at least 1 week and provides chromatographic properties that facilitate separation of these chemically similar compounds by reverse phase chromatography. PMID:24510541

  14. Opportunities for the Welfare Improvement of Laying Hens under Semi-open Rearing during the Cold Period with Arginine and Vitamin C Supplementation

    OpenAIRE

    BOZAKOVA, Nadya; GERZILOV, Vasko

    2014-01-01

    The purpose of the present study was to evaluate the welfare of DeKalb Brown laying hens whose feed was supplemented with 1% L-arginine or either with a combination arginine and vitamin C during the cold winter days, using a assessment model. The welfare was scored on the basis of hen’s behaviour, plasma corticosterone and several blood biochemical parameters. The extremely low environmental temperatures during the cold period provoked in DeKalb Brown hens a cold stress, manifested with exces...

  15. NO synthesis from arginine is favored by α-linolenic acid in mice fed a high-fat diet.

    Science.gov (United States)

    Hermier, Dominique; Guelzim, Najoua; Martin, Pascal G P; Huneau, Jean-François; Mathé, Véronique; Quignard-Boulangé, Annie; Lasserre, Frédéric; Mariotti, François

    2016-09-01

    Alterations in NO availability and signaling play a pivotal role at early stages of the metabolic syndrome (MetSynd). We hypothesized that dietary α-linolenic acid (ALA, 18:3 n-3) favors NO availability by modulating amino acid metabolism, with a specific impact on the arginine-NO pathway. Mice were fed a hyperlipidic diet (285 g lipid/kg, 51.1 % energy), rich in either saturated fatty acids (SFA, provided by palm oil, PALM group) or ALA (provided by linseed oil, LIN group). We measured whole-body NO synthesis and systemic arginine hydrolysis with a tracer-based method, plasma concentration of related metabolites, and hepatic mRNA level of related enzymes, and the study was completed by a transcriptomic analysis in the liver. As expected with this model, hyperlipidic diets resulted in increased adiposity and glycemia after 5 weeks. As compared to PALM mice, LIN mice had a higher plasma nitrite and nitrate concentration, a higher whole-body conversion of arginine into NO vs urea, and a similar plasma concentration of asymmetric dimethylarginine (ADMA), despite a higher expression of the liver dimethylargininase-1. In LIN mice, there was a higher expression of genes involved in PPARα signaling, but a little impact on gene expression related to amino acids and arginine metabolism. This effect cannot be directly ascribed to changes in arginase activity in the liver or ADMA metabolism, nor to direct regulation of the related target genes. In conclusion, dietary ALA favors NO synthesis, which could contribute to rescue NO availability when jeopardized by the nutritional conditions in relation with the initiation of the MetSynd. PMID:27178023

  16. Concurrent supplementation of arginine, vitamin E, and vitamin C improve cardiopulmonary performance in broilers chickens.

    Science.gov (United States)

    Ruiz-Feria, C A

    2009-03-01

    Two experiments were conducted to evaluate the effects of arginine, vitamin E (VE), and vitamin C (VC) on cardiopulmonary performance and ascites parameters of broilers reared under a cold environmental temperature. One-day-old male broilers were fed a basal corn-soybean meal diet (control, 1.2% arginine and 40 IU of VE), or the basal diet supplemented with 1% arginine and either 200 IU vitamin E (AE), 500 mg of vitamin C (AC), or a combination of VE and VC at the same amounts (AEC) per kilogram of feed. Pulmonary arterial pressure (PAP) and mean arterial pressure were recorded in clinically healthy, anesthetized birds (28 to 42 d old) before and after an epinephrine (Epi) challenge (0.5 mg/kg of BW, i.v.), an aminoguanidine hemisulfate challenge (100 mg/kg of BW, i.v.), and an N-nitro-l-arginine methyl ester challenge (50 mg/kg of BW, i.v.) at 20-min intervals. Data were analyzed by repeated measures ANOVA, and the Student Newman-Keuls test was used to separate means within groups. The PAP increased 30 s after the Epi challenge in all birds, but the peak PAP was lower in the AEC group than in all the other groups, whereas birds in the AE and AC groups had lower PAP peaks than did the control group. After 120 s of challenge, the PAP was lower in AEC birds compared with the other birds. The PAP returned to pre-Epi amounts within 300 s in all groups. The PAP was increased (P < 0.05) within 60 s after the aminoguanidine hemisulfate and N-nitro-l-arginine methyl ester challenges in all groups, but no differences were found among groups. The mean arterial pressure responses did not differ among groups. Plasma NO was greater in the AEC group than in all the other groups before and after the Epi challenge. These results showed that Epi elicited lower amplitude PAP and less prolonged increases in PAP in birds from the AEC group, and this may have been related to the increased vasodilation attributable to NO production. The AEC may have had complementary effects against

  17. Cellular Mechanisms of L-arginine Induced Experimental Acute Pancreatitis

    OpenAIRE

    Masood, Omar

    2013-01-01

    AbstractThe University Of ManchesterOmar MasoodMD Thesis 2013Cellular Mechanisms of L-arginine Induced Experimental Acute Pancreatitis. IntroductionImpairment of cytosolic calcium ([Ca2+]i) signaling and in particular calcium overload has emerged as a possible unifying mechanism for precipitating acute pancreatitis (AP.)In the L-arginine (L-arg) experimental model of AP, nitric oxide (NO) has been implicated however the disease progression is largely unaffected by nitric oxide synthase (NOS) ...

  18. L-Arginine Pathway in COPD Patients with Acute Exacerbation

    DEFF Research Database (Denmark)

    Ruzsics, Istvan; Nagy, Lajos; Keki, Sandor; Sarosi, Veronika; Illes, Balazs; Illes, Zsolt; Horvath, Ildiko; Bogar, Lajos; Molnar, Tihamer

    BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remains a major cause of mortality. Clinical criteria of AECOPD are subjective. Biomarkers for AECOPD may aid in the initiation of early treatment. Increased production of asymmetric and symmetric dimethylarginine (A......-arginine, ADMA and SDMA serum levels. In patients with AECOPD, production of ADMA and SDMA are more pronounced presumably due to more severe hypoxic insult. Methylated arginine derivatives in the sera may help early recognition of AECOPD....

  19. Does cold plasma affect breaking dormancy and seed germination? Study on seeds of Lamb's Quarters (Chenopodium album agg.)

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena; Šerý, M.; Straňák, V.; Špatenka, P.; Tichý, M.

    2009-01-01

    Roč. 11, č. 6 (2009), s. 750-754. ISSN 1009-0630 Institutional research plan: CEZ:AV0Z60870520 Keywords : chenopodium album * low-pressure discharge * plasma treatment Subject RIV: EF - Botanics Impact factor: 0.380, year: 2009

  20. Inhibition of platelet aggregation by polyaspartoyl L-arginine and its mechanism

    Institute of Scientific and Technical Information of China (English)

    Yin-ye WANG; Zhi-yu TANG; Min DONG; Xiao-yan LIU; Shi-qi PENG

    2004-01-01

    AIM: To observe the oral anti-platelet efficacy and the potential action mechanism of polyaspartoyl L-arginine (PDR), a new L-arginine rich compound. METHODS: Platelet aggregation was conducted by Born's method;bleeding time was determined using tail's bleeding time in mice; platelet adhesion was carried out with glass bottle method; nitric oxide (NO) was tested with Griess' method; and cAMP, thromboxane B2 (TXB2) and 6-keto-PGF1a were assessed with commercial kits. RESULTS: The inhibition by PDR (15-60 mg/kg ig or 10 mg/kg iv) of platelet aggregation induced by adenosine diphosphate (ADP), collagen or thrombin at 1 h after oral administration or at 20 min after iv injection for rats (P<0.01), and its (15 mg/kg, ig) inhibition of ADP-induced platelet aggregation for rabbits during 6 h after administration were observed. PDR (15-60 mg/kg) prolonged the bleeding time of mice (P<0.05) and (30 mg/kg) increased NO concentration in plasma. On the other hand PDR did not change the contents of cAMP in platelet and TXB2 or 6-keto-PGF1a in plasma. CONCLUSION: PDR is a novel, oral effective platelet aggregation inhibitor and its action mechanism possibly related to increasing NO generation.

  1. Acellular matrix of bovine pericardium bound with L-arginine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Joo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Bae, Jin Woo [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of); Kim, Chun Ho [Laboratory of Tissue Engineering, Korea Cancer Center Hospital, Seoul 139-240 (Korea, Republic of); Lee, Jin Woo [Department of Orthopaedic Surgery, College of Medicine, Yonsei University, Seoul 120-749 (Korea, Republic of); Shin, Jung Woog [Department of Biomedical Engineering, Inje University, Gimhae 621-749 (Korea, Republic of); Park, Ki Dong [Department of Molecular Science and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

    2007-09-15

    Surface immobilization of bioactive molecules onto natural tissues has been interestingly studied for the development of new functional matrices for the replacement of lost or malfunctioning tissues. In this study, an acellular matrix of bovine pericardium (ABP) was chemically modified by the direct coupling of L-arginine after glutaraldehyde (GA) cross-linking. The effects of L-arginine coupling on durability and calcification were investigated and the biocompatibility was evaluated in vitro and in vivo. A four-step detergent and enzymatic extraction process has been utilized to remove cellular components from fresh bovine pericardium (BP). Microscopic observation confirmed that nearly all cellular constituents are removed. Thermal and mechanical properties showed that the durability of L-arginine-treated matrices increased as compared with control ABP and GA-treated ABP. Resistance to collagenase digestion revealed that modified matrices have greater resistance to enzyme digestion than control ABP and GA-treated ABP. The in vivo calcification study demonstrated much less calcium deposition on L-arginine-treated ABP than GA-treated one. In vitro cell viability results showed that ABP modified with L-arginine leads to a significant increase in attachment of human dermal fibroblasts. The obtained results attest to the usefulness of L-arginine-treated ABP matrices for cardiovascular bioprostheses.

  2. Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters (Chenopodium album agg.)

    International Nuclear Information System (INIS)

    Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb's Quarters (Chenopodium album agg.) with different starting germinations (17%, 8%) and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards' equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb's Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb's Quarters seeds.

  3. Does overnight normalization of plasma glucose by insulin infusion affect assessment of glucose metabolism in Type 2 diabetes?

    DEFF Research Database (Denmark)

    Staehr, P; Højlund, Kurt; Hother-Nielsen, O;

    2003-01-01

    turnover rates were quantified by adjusted primed-constant 3-3H-glucose infusions, and insulin action was assessed in 4-h euglycaemic, hyperinsulinaemic (40 mU m-2 min-1) clamp studies using labelled glucose infusates (Hot-GINF). RESULTS: Basal plasma glucose levels (mean +/- sd) were 5.5 +/- 0.5 and 10...... from basal rates of Rd, assessment of glucose turnover rates in euglycaemic clamp studies of Type 2 diabetic patients is not dependent on the method by which plasma glucose levels are lowered........7 +/- 2.9 mmol/l in the + ON and - ON studies, respectively, and were clamped at -5.5 mmol/l. Basal rates of glucose production (GP) were similar in the + ON and - ON studies, 83 +/- 13 vs. 85 +/- 14 mg m-2 min-1 (NS), whereas basal rates of glucose disappearance (Rd) were lower in the + ON than in the...

  4. Does Cold Plasma Affect Breaking Dormancy and Seed Germination? A Study on Seeds of Lamb's Quarters (Chenopodium album agg.)

    Science.gov (United States)

    Božena, Šerá; Michal, Šerý; Vitězslav, Štrañák; Petr, Špatenka; Milan, tichý

    2009-12-01

    Low-pressure discharge is applied for stimulation of germination of two seed lots of Lamb's Quarters (Chenopodium album agg.) with different starting germinations (17%, 8%) and in different stages of dormancy. Different exposition durations with cold plasma treatment were applied. The variable of the ratio cumulative germination was calculated. The Richards' equation was used for curve-fitting and simulation of the growth curves. Population parameters, namely Vi - viability, Me - time, Qu - dispersion, and Sk - skewness, counted from the curves described the germination rate well. Significant differences among Qu confirmed the erratic dormancy and gradual germination of Lamb's Quarters. No difference in the Me parameter was found between two tested seed lots, and no interspecies characteristics were changed using low-pressure discharge. The results suggested that plasma treatment changed seed germination in Lamb's Quarters seeds.

  5. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels

    Science.gov (United States)

    Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.

    2016-02-01

    Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD.

  6. Ageing and long-term smoking affects KL-6 levels in the lung, induced sputum and plasma

    OpenAIRE

    Horimasu Yasushi; Rönty Mikko; Vuopala Katri; Toljamo Tuula; Mazur Witold; Ishikawa Nobuhisa; Kohno Nobuoki; Kinnula Vuokko L

    2011-01-01

    Abstract Background KL-6 is a high-molecular-weight glycoprotein classified as a human MUC1 mucin. It was hypothesized that KL-6 could be detectable in the circulating blood and especially in airway secretions in lung diseases associated with mucus production such as chronic obstructive pulmonary disease (COPD). Additional aims of this study were to investigate whether the levels of KL-6 in plasma and sputum are related to ageing and smoking history. Methods The concentrations of KL-6 in plas...

  7. Severity and timing: How prenatal stress exposure affects glial developmental, emotional behavioural and plasma neurosteroid responses in guinea pig offspring.

    Science.gov (United States)

    Bennett, Greer A; Palliser, Hannah K; Walker, David; Hirst, Jonathan

    2016-08-01

    Prenatal stress has been associated with a variety of developmental changes in offspring, notably those associated with brain development and subsequent risk for neuropathologies later in life. Recently, the importance of the timing and the severity of the stressor during pregnancy has been emphasized with neurosteroids including allopregnanolone implicated in the regulation of stress and also for endogenous neuroprotection in offspring. Prenatal stress was induced using strobe light exposure in pregnant guinea pigs (term 71days) in three defined stress exposure groups (Gestational Age (GA)35-65, GA50-65 and GA60-65). Stress was induced for 2h (9-11am) every 5days via strobe light exposure. A fetal cohort were euthanased at term with fetal brains and plasma collected. Anxiety-like behaviour was evaluated at 18 days of age in a separate cohort of offspring with brains and plasma collected at 21days of age. Markers for mature oligodendrocytes and reactive astrocytes were measured in the CA1 region of the hippocampus and the subcortical white matter. The neurosteroid allopregnanolone was measured by radioimmunoassay in offspring plasma. In the CA1 region of the hippocampus, fetuses from all stress groups showed reduced expression of mature oligodendrocytes and reactive astrocytes. By juvenility, all male stress exposure groups had recovered to levels of unaffected controls with the exception of the GA35-65 stress group. In juvenile females, mature oligodendrocyte marker expression was reduced in all stress groups and reactive astrocyte expression was reduced in the GA35-65 and GA60-65 stress groups by juvenility. Increased reactive astrocyte expression was also apparent in the subcortical white matter in both sexes both at term and at juvenility. Prenatally stressed offspring spent less time exploring in the object exploration test and also entered the inner zone of the open field less than controls at 18days of age. Circulating allopregnanolone concentrations were

  8. Different environmental temperatures affect amino acid metabolism in the eurytherm teleost Senegalese sole (Solea senegalensis Kaup, 1858) as indicated by changes in plasma metabolites.

    Science.gov (United States)

    Costas, Benjamín; Aragão, Cláudia; Ruiz-Jarabo, Ignacio; Vargas-Chacoff, Luis; Arjona, Francisco J; Mancera, Juan M; Dinis, Maria T; Conceição, Luís E C

    2012-07-01

    Senegalese sole (Solea senegalensis) is a eurytherm teleost that under natural conditions can be exposed to annual water temperature fluctuations between 12 and 26°C. This study assessed the effects of temperature on sole metabolic status, in particular in what concerns plasma free amino acid changes during thermal acclimation. Senegalese sole maintained at 18°C were acclimated to either cold (12°C) or warm (26°C) environmental temperatures for 21 days. Fish maintained at 18°C served as control. Plasma concentrations of cortisol, glucose, lactate, triglycerides, proteins, and free amino acids were assessed. Cold acclimation influenced interrenal responses of sole by increasing cortisol release. Moreover, plasma glucose and lactate concentrations increased linearly with temperature, presumably reflecting a higher metabolic activity of sole acclimated to 26°C. Acclimation temperature affected more drastically plasma concentrations of dispensable than that of indispensable amino acids, and different acclimation temperatures induced different responses. Asparagine, glutamine and ornithine seem to be of particular importance for ammonia detoxification mechanisms, synthesis of triglycerides that may be used during homeoviscous adaptation and, to a lesser extent, as energetic substrates in specimens acclimated to 12°C. When sole is acclimated to 26°C taurine, glutamate, GABA and glycine increased, which may suggest important roles as antioxidant defences, in osmoregulatory processes and/or for energetic purposes at this thermal regimen. In conclusion, acclimation to different environmental temperatures induces several metabolic changes in Senegalese sole, suggesting that amino acids may be important for thermal acclimation. PMID:21947601

  9. Effects of Arginine Vasopressin on musical short-term memory

    Directory of Open Access Journals (Sweden)

    Roni Y. Granot

    2013-10-01

    Full Text Available Previous genetic studies showed an association between variations in the gene coding for the 1a receptor of the neuro-hormone arginine vasopressin (AVP and musical working memory (WM. The current study set out to test the influence of intranasal administration (INA of AVP on musical as compared to verbal WM using a double blind crossover (AVP – placebo design. Two groups of 25 males were exposed to 20 IU of AVP in one session, and 20 IU of saline water (placebo in a second session, one week apart. In each session subjects completed the tonal subtest from Gordon's Musical Aptitude Profile, the interval subtest from the Montreal Battery for Evaluation of Amusias (MBEA, and the forward and backward digit span tests. Scores in the digit span tests were not influenced by AVP. In contrast, in the music tests there was an AVP effect. In the MBEA test, scores for the group receiving placebo in the first session (PV were higher than for the group receiving vasopressin in the first session (VP (p < .05 with no main Session effect nor Group * Session interaction. In the Gordon test there was a main Session effect (p < .05 with scores higher in the second as compared to the first session, a marginal main Group effect (p = .093 and a marginal Group X Session interaction (p = 0.88. In addition we found that the group that received AVP in the first session scored higher on scales indicative of happiness, and alertness on the Positive and Negative Affect Scale, (PANAS. Only in this group and only in the music test these scores were significantly correlated with memory scores. Together the results reflect a complex interaction between AVP, musical memory, arousal, and contextual effects such as session, and base levels of memory. The results are interpreted in light of music's universal use as a means to modulate arousal on the one hand, and AVP's influence on mood, arousal, and social interactions on the other.

  10. Effects of arginine vasopressin on musical working memory.

    Science.gov (United States)

    Granot, Roni Y; Uzefovsky, Florina; Bogopolsky, Helena; Ebstein, Richard P

    2013-01-01

    Previous genetic studies showed an association between variations in the gene coding for the 1a receptor of the neuro-hormone arginine vasopressin (AVP) and musical working memory (WM). The current study set out to test the influence of intranasal administration (INA) of AVP on musical as compared to verbal WM using a double blind crossover (AVP-placebo) design. Two groups of 25 males were exposed to 20 IU of AVP in one session, and 20 IU of saline water (placebo) in a second session, 1 week apart. In each session subjects completed the tonal subtest from Gordon's "Musical Aptitude Profile," the interval subtest from the "Montreal Battery for Evaluation of Amusias (MBEA)," and the forward and backward digit span tests. Scores in the digit span tests were not influenced by AVP. In contrast, in the music tests there was an AVP effect. In the MBEA test, scores for the group receiving placebo in the first session (PV) were higher than for the group receiving vasopressin in the first session (VP) (p effect nor Group × Session interaction. In the Gordon test there was a main Session effect (p effect (p = 0.093) and a marginal Group × Session interaction (p = 0.88). In addition we found that the group that received AVP in the first session scored higher on scales indicative of happiness, and alertness on the positive and negative affect scale, (PANAS). Only in this group and only in the music test these scores were significantly correlated with memory scores. Together the results reflect a complex interaction between AVP, musical memory, arousal, and contextual effects such as session, and base levels of memory. The results are interpreted in light of music's universal use as a means to modulate arousal on the one hand, and AVP's influence on mood, arousal, and social interactions on the other. PMID:24151474

  11. Variation of the Concentration of Isotopes Copper and Zinc in Human Plasmas of Patients Affected by Cancer

    Science.gov (United States)

    Triassi, Antonio

    2006-02-01

    In this paper, we demonstrate that the increase of copper and the reduction of zinc in the human plasma of patient with cancer, and in particular the Lymphoid Leukaemia, is a consequence of the isotopic constant of the enzymatic components copper/zinc dependent (DNA/RNA polymerase). Our hypothesis is that the reaction happens at the nuclear level in the human cell, and it is due to the action of a neutron (probably of deuterium of water) (J.F. Thomson, Biological Effects of Deuterium, Pergamon Press, Oxford, 1963) with the isotopic component of 64Zn transmutation into 65Cu stable following reaction: [ ^{64}Zn + N(HDO) rightarrow ^{65}Zn rightarrow beta^+ rightarrow EC rightarrow gamma rightarrow ^{65}Cu ] this produces energy of 0.325 MeV for the β+ and equal energy of 1.118 MeV for the photon γ with a half-life of 250 days.

  12. Cell surface binding and uptake of arginine- and lysine-rich penetratin peptides in absence and presence of proteoglycans

    KAUST Repository

    Åmand, Helene L.

    2012-11-01

    Cell surface proteoglycans (PGs) appear to promote uptake of arginine-rich cell-penetrating peptides (CPPs), but their exact functions are unclear. To address if there is specificity in the interactions of arginines and PGs leading to improved internalization, we used flow cytometry to examine uptake in relation to cell surface binding for penetratin and two arginine/lysine substituted variants (PenArg and PenLys) in wildtype CHO-K1 and PG-deficient A745 cells. All peptides were more efficiently internalized into CHO-K1 than into A745, but their cell surface binding was independent of cell type. Thus, PGs promote internalization of cationic peptides, irrespective of the chemical nature of their positive charges. Uptake of each peptide was linearly dependent on its cell surface binding, and affinity is thus important for efficiency. However, the gradients of these linear dependencies varied significantly. Thus each peptide\\'s ability to stimulate uptake once bound to the cell surface is reliant on formation of specific uptake-promoting interactions. Heparin affinity chromatography and clustering experiments showed that penetratin and PenArg binding to sulfated sugars is stabilized by hydrophobic interactions and result in clustering, whereas PenLys only interacts through electrostatic attraction. This may have implications for the molecular mechanisms behind arginine-specific uptake stimulation as penetratin and PenArg are more efficiently internalized than PenLys upon interaction with PGs. However, PenArg is also least affected by removal of PGs. This indicates that an increased arginine content not only improve PG-dependent uptake but also that PenArg is more adaptable as it can use several portals of entry into the cell. © 2012 Elsevier B.V.

  13. Post-glucose-load urinary C-peptide and glucose concentration obtained during OGTT do not affect oral minimal model-based plasma indices.

    Science.gov (United States)

    Jainandunsing, Sjaam; Wattimena, J L Darcos; Rietveld, Trinet; van Miert, Joram N I; Sijbrands, Eric J G; de Rooij, Felix W M

    2016-05-01

    The purpose of this study was to investigate how renal loss of both C-peptide and glucose during oral glucose tolerance test (OGTT) relate to and affect plasma-derived oral minimal model (OMM) indices. All individuals were recruited during family screening between August 2007 and January 2011 and underwent a 3.5-h OGTT, collecting nine plasma samples and urine during OGTT. We obtained the following three subgroups: normoglycemic, at risk, and T2D. We recruited South Asian and Caucasian families, and we report separate analyses if differences occurred. Plasma glucose, insulin, and C-peptide concentrations were analyzed as AUCs during OGTT, OMM estimate of renal C-peptide secretion, and OMM beta-cell and insulin sensitivity indices were calculated to obtain disposition indices. Post-glucose load glucose and C-peptide in urine were measured and related to plasma-based indices. Urinary glucose corresponded well with plasma glucose AUC (Cau r = 0.64, P < 0.01; SA r = 0.69, P < 0.01), S I (Cau r = -0.51, P < 0.01; SA r = -0.41, P < 0.01), Φ dynamic (Cau r = -0.41, P < 0.01; SA r = -0.57, P < 0.01), and Φ oral (Cau r = -0.61, P < 0.01; SA r = -0.73, P < 0.01). Urinary C-peptide corresponded well to plasma C-peptide AUC (Cau r = 0.45, P < 0.01; SA r = 0.33, P < 0.05) and OMM estimate of renal C-peptide secretion (r = 0.42, P < 0.01). In general, glucose excretion plasma threshold for the presence of glucose in urine was ~10-10.5 mmol L(-1) in non-T2D individuals, but not measurable in T2D individuals. Renal glucose secretion during OGTT did not influence OMM indices in general nor in T2D patients (renal clearance range 0-2.1 %, with median 0.2 % of plasma glucose AUC). C-indices of urinary glucose to detect various stages of glucose intolerance were excellent (Cau 0.83-0.98; SA 0.75-0.89). The limited role of renal glucose secretion validates the neglecting of urinary glucose secretion in kinetic models of glucose

  14. Arginine protection against ammonia toxicity in exhausted rat.

    Science.gov (United States)

    Krishna Mohan, P; Indira, K; Rajendra, W

    1987-01-01

    Arginine administration (5 m moles/kg/day) to albino rats for 7 days, revealed that this vital basic amino acid possesses latent potentiality for the accentuation of urea cycle or at least for arginase activity. The mitigation of ammonia toxicity was observed to be more effective in the case of gastrocnemius and red vastus as compared to white vastus. Further, ammonia and lactate levels were also decreased by arginine in blood and thereby delaying the onset of fatigue by preventing ammonotoxemia and lactic acidemia. PMID:3666875

  15. A clinical evaluation to determine the safety, pharmacokinetics, and pharmacodynamics of an inositol-stabilized arginine silicate dietary supplement in healthy adult males

    Directory of Open Access Journals (Sweden)

    Kalman DS

    2015-10-01

    Full Text Available Douglas S Kalman, Samantha Feldman, Adam Samson, Diane R Krieger Miami Research Associates, Miami, FL, USA Purpose: The purpose of this study was to characterize the pharmacokinetics (PKs and pharmacodynamics (PDs of an oral inositol-stabilized arginine silicate dietary supplement. Subjects and methods: Ten healthy males, 26.7±5.4 years, took three 500 mg arginine silicate capsules (active product for 14 days. The subjects attended test visits on Days 1 and 14. Fasting blood and saliva collections were performed predose and at 0.5 hours, 1 hour, 1.5 hours, 2 hours, 3 hours, 4 hours, 5 hours, and 6 hours postdose for plasma arginine, serum silicon, and salivary nitric oxide (NO + nitrite. Results: Day 1 PK parameters (adjusted for body weight for arginine were peak serum concentration (CMax 30.06±7.80 µg/mL, time it takes to reach peak serum concentration (tMax 1.13±0.52 hours, and time required to reach half its original concentration (t1/2 15.93±9.55 hours and for silicon were CMax 2.99±0.63 µg/mL, tMax 2.44±2.05 hours, and t1/2 34.56±16.56 hours. After Day 1 dose, arginine levels increased at 0.5 hours, 1 hour, 1.5 hours, 2 hours, 3 hours, and 5 hours (P<0.01 and silicon levels increased at 1 hour and 1.5 hours (P<0.05. After Day 14 dose, arginine levels increased at 0.5 hours, 1 hour, and 1.5 hours (P<0.05 and silicon levels increased at 1 hour, 1.5 hours, 2 hours, and 3 hours (P<0.01. After 14 days of use, baseline arginine trended toward being higher than baseline Day 1 (P=0.0645, and 4-hour postdose plasma arginine was significantly higher (P=0.0488 at Day 14 than Day 1. Although not a significant difference, NO, as measured as salivary nitrate, increased in four subjects and stayed the same in six subjects at 0.5 hours after the first dose (P=0.125. After 14 days of use, baseline NO levels increased in six subjects and stayed the same in four subjects; this shift was significant (P=0.031. Conclusion: The arginine silicate dietary

  16. The concentration of plasma metabolites varies throughout reproduction and affects offspring number in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Gauthey, Zoé; Freychet, Marine; Manicki, Aurélie; Herman, Alexandre; Lepais, Olivier; Panserat, Stéphane; Elosegi, Arturo; Tentelier, Cédric; Labonne, Jacques

    2015-06-01

    In wild populations, measuring energy invested in the reproduction and disentangling investment in gametes versus investment in reproductive behavior (such as intrasexual competition or intersexual preference) remain challenging. In this study, we investigated the energy expenditure in brown trout reproductive behavior by using two proxies: variation in weight and variation of plasma metabolites involved in energy production, over the course of reproductive season in a semi natural experimental river. We estimated overall reproductive success using genetic assignment at the end of the reproductive season. Results show that triglycerides and free fatty acid concentrations vary negatively during reproduction, while amino-acids and glucose concentrations remain stable. Decrease in triglyceride and free fatty acid concentrations during reproduction is not related to initial concentration levels or to weight variation. Both metabolite concentration variations and weight variations are correlated to the number of offspring produced, which could indicate that gametic and behavioral reproductive investments substantially contribute to reproductive success in wild brown trout. This study opens a path to further investigate variations in reproductive investment in wild populations. PMID:25666363

  17. Biosynthesis of homoarginine (hArg) and asymmetric dimethylarginine (ADMA) from acutely and chronically administered free L-arginine in humans.

    Science.gov (United States)

    Kayacelebi, Arslan Arinc; Langen, Jennifer; Weigt-Usinger, Katharina; Chobanyan-Jürgens, Kristine; Mariotti, François; Schneider, Jessica Y; Rothmann, Sabine; Frölich, Jürgen C; Atzler, Dorothee; Choe, Chi-Un; Schwedhelm, Edzard; Huneau, Jean François; Lücke, Thomas; Tsikas, Dimitrios

    2015-09-01

    Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis, whereas L-arginine (Arg) and L-homoarginine (hArg) serve as substrates for NO synthesis. ADMA and other methylated arginines are generally believed to exclusively derive from guanidine (N (G))-methylated arginine residues in proteins by protein arginine methyltransferases (PRMTs) that use S-adenosylmethionine (SAM) as the methyl donor. L-Lysine is known for decades as a precursor for hArg, but only recent studies indicate that arginine:glycine amidinotransferase (AGAT) is responsible for the synthesis of hArg. AGAT catalyzes the formation of guanidinoacetate (GAA) that is methylated to creatine by guanidinoacetate methyltransferase (GAMT) which also uses SAM. The aim of the present study was to learn more about the mechanisms of ADMA and hArg formation in humans. Especially, we hypothesized that ADMA is produced by N (G)-methylation of free Arg in addition to the known PRMTs-involving mechanism. In knockout mouse models of AGAT- and GAMT-deficiency, we investigated the contribution of these enzymes to hArg synthesis. Arg infusion (0.5 g/kg, 30 min) in children (n = 11) and ingestion of high-fat protein meals by overweight men (n = 10) were used to study acute effects on ADMA and hArg synthesis. Daily Arg ingestion (10 g) or placebo for 3 or 6 months by patients suffering from peripheral arterial occlusive disease (PAOD, n = 20) or coronary artery disease (CAD, n = 30) was used to study chronic effects of Arg on ADMA synthesis. Mass spectrometric methods were used to measure all biochemical parameters in plasma and urine samples. In mice, AGAT but not GAMT was found to contribute to plasma hArg, while ADMA synthesis was independent of AGAT and GAMT. Arg infusion acutely increased plasma Arg, hArg and ADMA concentrations, but decreased the plasma hArg/ADMA ratio. High-fat protein meals acutely increased plasma Arg, hArg, ADMA concentrations, as well as the plasma h

  18. Site-directed mutagenesis studies on the L-arginine-binding sites of feedback inhibition in N-acetyl-L-glutamate kinase (NAGK) from Corynebacterium glutamicum.

    Science.gov (United States)

    Xu, Meijuan; Rao, Zhiming; Dou, Wenfang; Jin, Jian; Xu, Zhenghong

    2012-02-01

    Arginine biosynthesis in Corynebacterium glutamicum proceeds via a pathway that is controlled by arginine through feedback inhibition of NAGK, the enzyme that converts N-acetyl-L-glutamate (NAG) to N-acety-L-glutamy-L-phosphate. In this study, the gene argB encoding NAGK from C. glutamicum ATCC 13032 was site-directed, and the L-arginine-binding sites of feedback inhibition in Cglu_NAGK are described. The N-helix and C-terminal residues were first deleted, and the results indicated that they are both necessary for Cglu_NAGK, whereas, the complete N-helix deletion (the front 28 residues) abolished the L-arginine inhibition. Further, we study here the impact on these functions of 12 site-directed mutations affecting seven residues of Cglu_NAGK, chosen on the basis of homology structural alignment. The E19R, H26E, and H268N variants could increase the I₀.₅ (R) 50-60 fold, and the G287D and R209A mutants could increase the I₀.₅ (R) 30-40 fold. The E281A mutagenesis resulted in the substrate kinetics being greatly influenced. The W23A variant had a lower specific enzyme activity. These results explained that the five amino acid residues (E19, H26, R209, H268, and G287) located in or near N-helix are all essential for the formation of arginine inhibition. PMID:22101454

  19. Effect of oral L-arginine administration on exhaled nitric oxide (no) concentration in healthy volunteers

    OpenAIRE

    Ogata, Hiroshi; Yatabe, Midori; Misaka, Shingen; Shikama, Yayoi; Sato, Suguru; Munakata, Mitsuru; Kimura, Junko

    2013-01-01

    We previously reported a case of pulmonary hypertension, where the symptoms were improved by oral L-arginine (arginine) administration. Arginine may increase nitric oxide (NO) production in the pulmonary artery. Exhaled NO may reflect pulmonary artery NO production. It has been demonstrated that exhaled NO concentration is higher in patients with allergic diseases, but whether oral arginine administration alters exhaled NO is unknown. Therefore, in this study, we investigated whether oral arg...

  20. The effect of recombinant erythropoietin on plasma brain derived neurotrophic factor levels in patients with affective disorders: a randomised controlled study.

    Directory of Open Access Journals (Sweden)

    Maj Vinberg

    Full Text Available The study aims to investigate the effect of repeated infusions of recombinant erythropoietin (EPO on plasma brain derived neurotrophic factor (BDNF levels in patients with affective disorders. In total, 83 patients were recruited: 40 currently depressed patients with treatment-resistant depression (TRD (Hamilton Depression Rating Scale-17 items (HDRS-17 score >17 (study 1 and 43 patients with bipolar disorder (BD in partial remission (HDRS-17 and Young Mania Rating Scale (YMRS ≤ 14 (study 2. In both studies, patients were randomised to receive eight weekly EPO (Eprex; 40,000 IU or saline (0.9% NaCl infusions in a double-blind, placebo-controlled, parallel--group design. Plasma BDNF levels were measured at baseline and at weeks 5, 9 and at follow up, week 14. In contrast with our hypothesis, EPO down regulated plasma BDNF levels in patients with TRD (mean reduction at week 9 (95% CI: EPO 10.94 ng/l (4.51-21.41 ng/l; mean increase at week 9: Saline 0.52 ng/l, p=0.04 (-5.88-4.48 ng/l p=0.04, partial ŋ2=0.12. No significant effects were found on BDNF levels in partially remitted patients with BD (p=0.35. The present effects of EPO on BDNF levels in patients with TRD point to a role of neurotrophic factors in the potential effects of EPO seen in TRD and BD. The neurobiological mechanisms underlying these effects and the interaction between EPO and peripheral levels on BDNF need to be further elucidated in human studies including a broad range of biomarkers.ClinicalTrials.gov: NCT00916552.

  1. Changes in Plasma Copeptin Levels during Hemodialysis : Are the Physiological Stimuli Active in Hemodialysis Patients?

    NARCIS (Netherlands)

    Ettema, Esmee M.; Kuipers, Johanna; Assa, Solmaz; Bakker, Stephan J. L.; Groen, Henk; Westerhuis, Ralf; Gaillard, Carlo A. J. M.; Gansevoort, Ron T.; Franssen, Casper F. M.

    2015-01-01

    Objectives Plasma levels of copeptin, a surrogate marker for the vasoconstrictor hormone arginine vasopressin (AVP), are increased in hemodialysis patients. Presently, it is unknown what drives copeptin levels in hemodialysis patients. We investigated whether the established physiological stimuli fo

  2. Theoretical insights into catalytic mechanism of protein arginine methyltransferase 1.

    Directory of Open Access Journals (Sweden)

    Ruihan Zhang

    Full Text Available Protein arginine methyltransferase 1 (PRMT1, the major arginine asymmetric dimethylation enzyme in mammals, is emerging as a potential drug target for cancer and cardiovascular disease. Understanding the catalytic mechanism of PRMT1 will facilitate inhibitor design. However, detailed mechanisms of the methyl transfer process and substrate deprotonation of PRMT1 remain unclear. In this study, we present a theoretical study on PRMT1 catalyzed arginine dimethylation by employing molecular dynamics (MD simulation and quantum mechanics/molecular mechanics (QM/MM calculation. Ternary complex models, composed of PRMT1, peptide substrate, and S-adenosyl-methionine (AdoMet as cofactor, were constructed and verified by 30-ns MD simulation. The snapshots selected from the MD trajectory were applied for the QM/MM calculation. The typical SN2-favored transition states of the first and second methyl transfers were identified from the potential energy profile. Deprotonation of substrate arginine occurs immediately after methyl transfer, and the carboxylate group of E144 acts as proton acceptor. Furthermore, natural bond orbital analysis and electrostatic potential calculation showed that E144 facilitates the charge redistribution during the reaction and reduces the energy barrier. In this study, we propose the detailed mechanism of PRMT1-catalyzed asymmetric dimethylation, which increases insight on the small-molecule effectors design, and enables further investigations into the physiological function of this family.

  3. Effect of iron, taurine and arginine on rat hepatic fibrosis

    International Nuclear Information System (INIS)

    Objective: The promotion role of iron on pathogenesis of hepatic fibrosis and the protective role of taurine and L-arginine against hepatic fibrosis were studied. Method: The model of rat radiation hepatic fibrosis was used. Experimental rats were divided into 0 Gy, 30 Gy, 30 Gy + iron, 30 Gy + taurine and 30 Gy + L-arginine groups. Serum iron, liver tissue hydroxyproline (Hyp) and malondialdehyde (MDA) were measured one and three months respectively after irradiation of hepatic tissue, production and distribution characteristics of hepatic tissue type I and III collagen were observed with a polarizing microscope. Results: Administration of iron agent could significantly increase hepatic tissue MDA content and serum iron concentration, one month after irradiation, hepatic tissue Hyp in 30 Gy + iron group began to increase, and collagen in hepatic tissue obviously increased. Taurine and L-arginine could reduce serum iron concentration and decrease production of hepatic fissure Hyp. Conclusion: Exogenous iron agent could promote early development of radiation hepatic fibrosis; taurine and arginine could diminish pathologic alteration of hepatic fibrosis to a certain extent

  4. Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2014-01-01

    Full Text Available We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra.

  5. Expression of arg genes of Escherichia coli during arginine limitation dependent upon stringent control of translation.

    OpenAIRE

    Williams, M.G.; Rogers, P

    1987-01-01

    The transcription and translation of operons for arginine biosynthetic enzymes after arginine removal (arginine down shift) were studied in relA and relA+ strains of Escherichia coli. After arginine down shift, derepression of synthesis of the arginine biosynthetic enzymes ornithine carbamoyltransferase (argF) and argininosuccinate lyase (argH) began at about 15 min in relA+ cells but was delayed in relA cells for more than 2 h. However, both relA+ and relA cells accumulated high levels of ar...

  6. Differential effects of arginine, glutamate and phosphoarginine on Ca(2+)-activation properties of muscle fibres from crayfish and rat.

    Science.gov (United States)

    Jame, David W; West, Jan M; Dooley, Philip C; Stephenson, D George

    2004-01-01

    The effects of two amino acids, arginine which has a positively charged side-chain and glutamate which has a negatively charged side-chain on the Ca2+-activation properties of the contractile apparatus were examined in four structurally and functionally different types of skeletal muscle; long- and short-sarcomere fibres from the claw muscle of the yabby (a freshwater decapod crustacean), and fast- and slow-twitch fibres from limb muscles of the rat. Single skinned fibres were activated in carefully balanced solutions of different pCa (-log10[Ca2+]) that either contained the test solute ("test") or not ("control"). The effect of phosphoarginine, a phosphagen that bears a nett negative charge, was also compared to the effects of arginine. Results show that (i) arginine (33-36 mmol l(-1)) significantly shifted the force-pCa curve by 0.08-0.13 pCa units in the direction of increased sensitivity to Ca2+-activated contraction in all fibre types; (ii) phosphoarginine (9-10 mmol l(-1)) induced a significant shift of the force-pCa curve by 0.18-0.24 pCa units in the direction of increased sensitivity to Ca2+ in mammalian fast- and slow-twitch fibres, but had no significant effects on the force-pCa relation in either long- or short-sarcomere crustacean fibres; (iii) glutamate (36-40 mmol l(-1)), like arginine affected the force-pCa relation of all fibre types investigated, but in the opposite direction, causing a significant decrease in the sensitivity to Ca2+-activated contraction by 0.08-0.19 pCa units; (iv) arginine, phosphoarginine and glutamate had little or no effect on the maximum Ca2+-activated force of crustacean and mammalian fibres. The results suggest that the opposing effects of glutamate and arginine are not related to simply their charge structure, but must involve complex interactions between these molecules, Ca2+ and the regulatory and other myofibrillar proteins. PMID:15711880

  7. Enthalpy-driven interactions with sulfated glycosaminoglycans promote cell membrane penetration of arginine peptides.

    Science.gov (United States)

    Takechi-Haraya, Yuki; Nadai, Ryo; Kimura, Hitoshi; Nishitsuji, Kazuchika; Uchimura, Kenji; Sakai-Kato, Kumiko; Kawakami, Kohsaku; Shigenaga, Akira; Kawakami, Toru; Otaka, Akira; Hojo, Hironobu; Sakashita, Naomi; Saito, Hiroyuki

    2016-06-01

    The first step of cell membrane penetration of arginine peptides is thought to occur via electrostatic interactions between positive charges of arginine residues and negative charges of sulfated glycosaminoglycans (GAGs) on the cell surface. However, the molecular interaction of arginine peptides with GAG still remains unclear. Here, we compared the interactions of several arginine peptides of Tat, R8, and Rev and their analogues with heparin in relation to the cell membrane penetration efficiency. The high-affinity binding of arginine peptides to heparin was shown to be driven by large favorable enthalpy contributions, possibly reflecting multidentate hydrogen bondings of arginine residues with sulfate groups of heparin. Interestingly, the lysine peptides in which all arginine residues are substituted with lysine residues exhibited negligible binding enthalpy despite of their considerable binding to heparin. In CHO-K1 cells, arginine peptides exhibited a great cell-penetrating ability whereas their corresponding lysine peptides did not penetrate into cells. The degree of cell penetration of arginine peptides markedly decreased by the chlorate treatment of cells which prevents the sulfation of GAG chains. Significantly, the cell penetration efficiency of arginine peptides was found to be correlated with the favorable enthalpy of binding to heparin. These results suggest that the enthalpy-driven strong interaction with sulfated GAGs such as heparan sulfate plays a critical role in the efficient cell membrane penetration of arginine peptides. PMID:27003128

  8. Proteome-wide analysis of arginine monomethylation reveals widespread occurrence in human cells.

    Science.gov (United States)

    Larsen, Sara C; Sylvestersen, Kathrine B; Mund, Andreas; Lyon, David; Mullari, Meeli; Madsen, Maria V; Daniel, Jeremy A; Jensen, Lars J; Nielsen, Michael L

    2016-01-01

    The posttranslational modification of proteins by arginine methylation is functionally important, yet the breadth of this modification is not well characterized. Using high-resolution mass spectrometry, we identified 8030 arginine methylation sites within 3300 human proteins in human embryonic kidney 293 cells, indicating that the occurrence of this modification is comparable to phosphorylation and ubiquitylation. A site-level conservation analysis revealed that arginine methylation sites are less evolutionarily conserved compared to arginines that were not identified as modified by methylation. Through quantitative proteomics and RNA interference to examine arginine methylation stoichiometry, we unexpectedly found that the protein arginine methyltransferase (PRMT) family of arginine methyltransferases catalyzed methylation independently of arginine sequence context. In contrast to the frequency of somatic mutations at arginine methylation sites throughout the proteome, we observed that somatic mutations were common at arginine methylation sites in proteins involved in mRNA splicing. Furthermore, in HeLa and U2OS cells, we found that distinct arginine methyltransferases differentially regulated the functions of the pre-mRNA splicing factor SRSF2 (serine/arginine-rich splicing factor 2) and the RNA transport ribonucleoprotein HNRNPUL1 (heterogeneous nuclear ribonucleoprotein U-like 1). Knocking down PRMT5 impaired the RNA binding function of SRSF2, whereas knocking down PRMT4 [also known as coactivator-associated arginine methyltransferase 1 (CARM1)] or PRMT1 increased the RNA binding function of HNRNPUL1. High-content single-cell imaging additionally revealed that knocking down CARM1 promoted the nuclear accumulation of SRSF2, independent of cell cycle phase. Collectively, the presented human arginine methylome provides a missing piece in the global and integrative view of cellular physiology and protein regulation. PMID:27577262

  9. Gliclazide directly inhibits arginine-induced glucagon release

    DEFF Research Database (Denmark)

    Cejvan, Kenan; Coy, David H; Holst, Jens Juul;

    2002-01-01

    Arginine-stimulated insulin and somatostatin release is enhanced by the sulfonylurea gliclazide. In contrast, gliclazide inhibits the glucagon response. The aim of the present study was to investigate whether this inhibition of glucagon release was mediated by a direct suppressive effect of...... specific antagonist of type 2 somatostatin receptor, DC-41-33 (2 micro mol/l), which fully antagonizes the suppressive somatostatin effect on rat A cells. Gliclazide (30 micro mol/l) inhibited glucagon release by 54% in the perfusion experiments, whereas the somatostatin response was nearly abolished. In...... islet perifusions with DC-41-33, arginine-induced glucagon release was inhibited by 66%. We therefore concluded that gliclazide inhibits glucagon release by a direct action on the pancreatic A cell....

  10. Obese women on a low energy rice and bean diet: effects of leucine, arginine or glycine supplementation on protein turnover

    Directory of Open Access Journals (Sweden)

    J.S. Marchini

    2001-10-01

    Full Text Available This study examined if leucine, arginine or glycine supplementation in adult obese patients (body mass index of 33 ± 4 kg/m² consuming a Brazilian low energy and protein diet (4.2 MJ/day and 0.6 g protein/kg affects protein and amino acid metabolism. After four weeks adaptation to this diet, each subject received supplements of these amino acids (equivalent to 0.2 g protein kg-1 day-1 in random order. On the seventh day of each amino acid supplementation, a single-dose 15N-glycine study was carried out. There were no significant differences in protein flux, synthesis or breakdown. The protein flux (grams of nitrogen, gN/9 h was 55 ± 24 during the nonsupplemented diet intake and 39 ± 10, 44 ± 22 and 58 ± 35 during the leucine-, glycine- and arginine-supplemented diet intake, respectively; protein synthesis (gN/9 h was 57 ± 24, 36 ± 10, 41 ± 22 and 56 ± 36, respectively; protein breakdown (gN/9 h was 51 ± 24, 34 ± 10, 32 ± 28 and 53 ± 35, respectively; kinetic balance (gN/9 h was 3.2 ± 1.8, 4.1 ± 1.7, 3.4 ± 2.9 and 3.9 ± 1.6. There was no difference in amino acid profiles due to leucine, arginine or glycine supplementation. The present results suggest that 0.6 g/kg of dietary protein is enough to maintain protein turnover in obese women consuming a reduced energy diet and that leucine, arginine or glycine supplementation does not change kinetic balance or protein synthesis.

  11. Arginine vasopressin in septic shock: supplement or substitute for norepinephrine?

    OpenAIRE

    Rehberg, Sebastian; Enkhbaatar, Perenlei; Traber, Daniel L

    2009-01-01

    In the current issue of Critical Care, Simon and coworkers investigated the effects of first-line arginine vasopressin (AVP) on organ function and systemic metabolism compared with norepinephrine in a pig model of fecal peritonitis. AVP was titrated according to the mean arterial pressure suggesting a vasopressor rather than a hormone replacement therapy. The study provides some evidence for the safety of this therapeutic approach. It needs to be determined whether AVP is most beneficial as a...

  12. Characterization of casein and Poly-L-arginine Multilayer Films

    OpenAIRE

    Warszynska, Lilianna Szyk; Kilan, Katarzyna; Socha, Robert P.

    2013-01-01

    Thin films containing casein appear to be a promising material for coatings used in the medical area to promote biomineralization. alfa- and beta-casein and poly-L-arginine multilayer films were formed by the layer-by layer technique and their thickness and mass were analyzed by ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D). We investigated the effect of the type of casein used for the film formation and of the polyethyleneimine anchoring layer on the thickn...

  13. The regulatory PII protein controls arginine biosynthesis in Arabidopsis.

    Science.gov (United States)

    Ferrario-Méry, Sylvie; Besin, Evelyne; Pichon, Olivier; Meyer, Christian; Hodges, Michael

    2006-04-01

    In higher plants, PII is a nuclear-encoded plastid protein which is homologous to bacterial PII signalling proteins known to be involved in the regulation of nitrogen metabolism. A reduced ornithine, citrulline and arginine accumulation was observed in two Arabidopsis PII knock-out mutants in response to NH4+ resupply after N starvation. This difference could be explained by the regulation of a key enzyme of the arginine biosynthesis pathway, N-acetyl glutamate kinase (NAGK) by PII. In vitro assays using purified recombinant proteins showed the catalytic activation of Arabidopsis NAGK by PII giving the first evidence of a physiological role of the PII protein in higher plants. Using Arabidopsis transcriptome microarray (CATMA) and RT-PCR analyses, it was found that none of the genes involved in the arginine biosynthetic or catabolic pathways were differentially expressed in a PII knock-out mutant background. In conclusion, the observed changes in metabolite levels can be explained by the reduced activation of NAGK by PII. PMID:16545809

  14. PRMT1-mediated arginine methylation controls ATXN2L localization

    International Nuclear Information System (INIS)

    Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine–glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory. - Highlights: • ATXN2L is asymmetrically dimethylated in vivo. • ATXN2L interacts with PRMT1 under normal and stress conditions. • PRMT1-mediated dimethylation of ATXN2L controls its nuclear localization. • ATXN2L localization to stress granules appears independent of its methylation state

  15. PRMT1-mediated arginine methylation controls ATXN2L localization

    Energy Technology Data Exchange (ETDEWEB)

    Kaehler, Christian; Guenther, Anika; Uhlich, Anja; Krobitsch, Sylvia, E-mail: krobitsc@molgen.mpg.de

    2015-05-15

    Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine–glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory. - Highlights: • ATXN2L is asymmetrically dimethylated in vivo. • ATXN2L interacts with PRMT1 under normal and stress conditions. • PRMT1-mediated dimethylation of ATXN2L controls its nuclear localization. • ATXN2L localization to stress granules appears independent of its methylation state.

  16. Systems pathway engineering of Corynebacterium crenatum for improved L-arginine production

    Science.gov (United States)

    Man, Zaiwei; Xu, Meijuan; Rao, Zhiming; Guo, Jing; Yang, Taowei; Zhang, Xian; Xu, Zhenghong

    2016-01-01

    L-arginine is an important amino acid in food and pharmaceutical industries. Until now, the main production method of L-arginine in China is the highly polluting keratin acid hydrolysis. The industrial level L-arginine production by microbial fermentation has become an important task. In previous work, we obtained a new L-arginine producing Corynebacterium crenatum (subspecies of Corynebacterium glutamicum) through screening and mutation breeding. In this work, we performed systems pathway engineering of C. crenatum for improved L-arginine production, involving amplification of L-arginine biosynthetic pathway flux by removal of feedback inhibition and overexpression of arginine operon; optimization of NADPH supply by modulation of metabolic flux distribution between glycolysis and pentose phosphate pathway; increasing glucose consumption by strengthening the preexisting glucose transporter and exploitation of new glucose uptake system; channeling excess carbon flux from glycolysis into tricarboxylic acid cycle to alleviate the glucose overflow metabolism; redistribution of carbon flux at α-ketoglutarate metabolic node to channel more flux into L-arginine biosynthetic pathway; minimization of carbon and cofactor loss by attenuation of byproducts formation. The final strain could produce 87.3 g L−1 L-arginine with yield up to 0.431 g L-arginine g−1 glucose in fed-batch fermentation. PMID:27338253

  17. Systems pathway engineering of Corynebacterium crenatum for improved L-arginine production.

    Science.gov (United States)

    Man, Zaiwei; Xu, Meijuan; Rao, Zhiming; Guo, Jing; Yang, Taowei; Zhang, Xian; Xu, Zhenghong

    2016-01-01

    L-arginine is an important amino acid in food and pharmaceutical industries. Until now, the main production method of L-arginine in China is the highly polluting keratin acid hydrolysis. The industrial level L-arginine production by microbial fermentation has become an important task. In previous work, we obtained a new L-arginine producing Corynebacterium crenatum (subspecies of Corynebacterium glutamicum) through screening and mutation breeding. In this work, we performed systems pathway engineering of C. crenatum for improved L-arginine production, involving amplification of L-arginine biosynthetic pathway flux by removal of feedback inhibition and overexpression of arginine operon; optimization of NADPH supply by modulation of metabolic flux distribution between glycolysis and pentose phosphate pathway; increasing glucose consumption by strengthening the preexisting glucose transporter and exploitation of new glucose uptake system; channeling excess carbon flux from glycolysis into tricarboxylic acid cycle to alleviate the glucose overflow metabolism; redistribution of carbon flux at α-ketoglutarate metabolic node to channel more flux into L-arginine biosynthetic pathway; minimization of carbon and cofactor loss by attenuation of byproducts formation. The final strain could produce 87.3 g L(-1) L-arginine with yield up to 0.431 g L-arginine g(-1) glucose in fed-batch fermentation. PMID:27338253

  18. Solubilization of aromatic and hydrophobic moieties by arginine in aqueous solutions

    Science.gov (United States)

    Li, Jianguo; Garg, Manju; Shah, Dhawal; Rajagopalan, Raj

    2010-08-01

    Experiments hold intriguing, circumstantial clues to the mechanisms behind arginine-mediated solubilization of small organic drugs and suppression of protein aggregation driven by hydrophobic or aromatic associations, but how exactly arginine's molecular structure and interactions contribute to its function remains unclear since attention has focused so far on the thermodynamics of the preferential exclusion or binding of arginine. Here, we examine, through molecular dynamics simulations, how arginine solubilizes nanoscale particles with hydrophobic surfaces or aromatic-ring-type surface interactions. We show that preferential, hydrophobic, and dispersion interactions of arginine's guanidinium group with the particles lead to a surfactant-like behavior of arginine around the particles and to a solvation layer with a protective polar mask creating a hydrophilic shell. Additionally, arginine-arginine association around the solvation layer further prevents aggregative contacts. The results shed some light on the mechanistic basis of arginine's function as a suppressant of protein aggregation, although the complex energy landscapes and kinetic pathways of aggregation are protein-dependent and pose formidable challenges to developing comprehensive mechanistic pictures. Our results suggest arginine's mode of interaction with hydrophobic patches and aromatic residues could reduce aggregation-prone intermediate states of proteins and shield protein-protein aggregative contacts. The approach used here offers a systematic way of exploring implications of other amino acid/excipient interactions by studying interactions of the excipient with particles grafted with amino acids.

  19. 血管加压素研究进展%Research Progress of Arginine Vasopressin

    Institute of Scientific and Technical Information of China (English)

    付志达

    2013-01-01

    Arginine vasopressin (AVP) is closely related to the pathogenesis of a variety of cardiovascular diseases and kidney diseases. Currently it is often used for the treatment of severe peripheral vasodilatory shock, and particularly beneficial for patients with refractory catecholamine-resistant vasodilatory shock. For some patients who do not have adequate AVP level in plasma after cardiovascular surgery, external low-dose AVP infusion is helpful to decrease the heart rate, and the dosage and duration of catecholamine use. Early initiation of low-dose AVP infusion may be beneficial for postoperative patients' hemodynamic recovery without adverse complications. More randomized control trials are needed to provide evidence for rational usage, dosage and duration of AVP administration.%血管加压素(arginine vasopressin,AVP)与多种心血管疾病和肾脏疾病的发生相关,目前主要用于治疗严重的外周血管扩张性休克,对于常规儿茶酚胺治疗效果不佳的患者尤为有效.心血管外科术后部分患者体内存在血管加压素相对不足,给予外源性血管加压素能够降低心率、减少儿茶酚胺类的使用量和使用时间.早期应用小剂量的血管加压素可能有助于患者术后血流动力学的恢复,而不会造成并发症的发生.进一步的随机对照试验,将为血管加压素的合理使用和剂量、疗程选择提供依据.

  20. Increasing levels of dietary crystalline methionine affect plasma methionine profiles, ammonia excretion, and the expression of genes related to the hepatic intermediary metabolism in rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Rolland, Marine; Skov, Peter V; Larsen, Bodil K; Holm, Jørgen; Gómez-Requeni, Pedro; Dalsgaard, Johanne

    2016-08-01

    Strictly carnivorous fish with high requirements for dietary protein, such as rainbow trout (Oncorhynchus mykiss) are interesting models for studying the role of amino acids as key regulators of intermediary metabolism. Methionine is an essential amino acid for rainbow trout, and works as a signalling factor in different metabolic pathways. The study investigated the effect of increasing dietary methionine intake on the intermediary metabolism in the liver of juvenile rainbow trout. For this purpose, five diets were formulated with increasing methionine levels from 0.60 to 1.29% dry matter. The diets were fed in excess for six weeks before three sampling campaigns carried out successively to elucidate (i) the hepatic expression of selected genes involved in lipid, glucose and amino acid metabolism; (ii) the postprandial ammonia excretion; and (iii) the postprandial plasma methionine concentrations. The transcript levels of enzymes involved in lipid metabolism (fatty acid synthase, glucose 6 phosphate dehydrogenase and carnitine palmitoyl transferase 1 a), gluconeogenesis (fructose-1,6-biphosphatase) and amino acid catabolism (alanine amino transferase and glutamate dehydrogenase) were significantly affected by the increase in dietary methionine. Changes in gene expression reflected to some extent the decrease in ammonia excretion (P=0.022) and in the hepatosomatic index (HSI; Ptrout responded in a dose-dependent manner to increasing levels of dietary methionine. PMID:27105833

  1. Arginine vasopressin in the pathogenesis of febrile convulsion and temporal lobe epilepsy.

    Science.gov (United States)

    Gulec, Guldal; Noyan, Behzat

    2002-11-15

    We aimed to investigate the possible convulsant action of arginine vasopressin (AVP) in both a febrile convulsion model in rat pups and a temporal lobe epilepsy model in adult rats and to define the receptor type which mediates this effect. In rat pups, 125 ng V2 receptor antagonist significantly prevented hyperthermic seizures, but did not affect seizure latency. In adult rats, the only effective dose and agent was 125 ng V2 receptor antagonist, which prevented pilocarpine-induced status epilepticus, extended the status epilepticus latency and improved the 24 h survival rate. These data suggest that AVP has a convulsant activity in febrile convulsions and also in seizures independent of fever, and this effect is mediated by V2 receptors. PMID:12438923

  2. Metabolic and clinical response to Escherichia coli lipopolysaccharide in layer pullets of different genetic backgrounds supplied with graded dietary L-arginine.

    Science.gov (United States)

    Lieboldt, M A; Frahm, J; Halle, I; Görs, S; Schrader, L; Weigend, S; Preisinger, R; Metges, C C; Breves, G; Dänicke, S

    2016-03-01

    L-arginine (Arg) is an essential amino acid in birds that plays a decisive role in avian protein synthesis and immune response. Effects of graded dietary Arg supply on metabolic and clinical response to Escherichia coli lipopolysaccharide (LPS) were studied over 48 hours after a single intramuscular LPS injection in 18-week-old genetically diverse purebred pullets. LPS induced a genotype-specific fever response within 4 hours post injectionem. Whereas brown genotypes showed an initial hypothermia followed by longer-lasting moderate hyperthermia, white genotypes exhibited a biphasic hyperthermia without initial hypothermia. Furthermore, within 2 hours after LPS injection, sickness behavior characterized by lethargy, anorexia, intensified respiration, and ruffled feathers appeared, persisted for 3 to 5 hours and recovered 12 hours post injectionem. The varying grades of Arg did not alter the examined traits named above, whereas insufficient Arg reduced body growth and increased relative weights of liver and pancreas significantly. At 48 hours post injectionem, increased relative weights of liver and spleen were also found in LPS treated pullets, whereas LPS decreased those of pancreas, bursa, thymus, and cecal tonsils. Moreover, LPS lowered the sum of plasma amino acids and decreased plasma concentrations of Arg, citrulline, glutamate, methionine, ornithine, phenylalanine, proline, tryptophan, and tyrosine, and increased those of aspartate, glutamine, lysine, 1- and 3-methyl-histidine. Elevating concentrations of dietary Arg led to increasing plasma concentrations of Arg, citrulline, ornithine, and 3-methyl-histidine subsequently. As quantitative expression of LPS-induced anorexia, proteolysis, and the following changes in plasma amino acids, pullets showed a significant decrease of feed and nitrogen intake and catabolic metabolism characterized by negative nitrogen balance and body weight loss in the first 24 hours post injectionem. Pullets recovered from the

  3. Changes of arginine vasopressin in elderly patients with acute traumatic cerebral injury

    Institute of Scientific and Technical Information of China (English)

    黄卫东; 杨云梅; 吴胜东

    2003-01-01

    Objective: To investigate the changes and clinical significance of arginine vasopressin (AVP) in elderly patients with acute traumatic cerebral injury. Methods: With radioimmunoassay, the plasma levels of AVP were measured in 32 elderly patients with acute traumatic cerebral injury, 30 traumatic patients without cerebral injury and 30 healthy elderly volunteers, respectively.Results: The plasma level of AVP in patients with acute traumatic cerebral injury in the early stage (48.30 ng/L±8.28 ng/L) was much higher than that of the traumatic patients without cerebral injury (25.56 ng/L±4.64 ng/L, P<0.01), which was much higher than that of the healthy volunteers (5.06 ng/L±4.12 ng/L, P<0.01). The level of AVP in the patients with acute traumatic cerebral injury was negatively related with GCS scores.Conclusions: AVP may play an important role in the pathophysiological process in patients with acute traumatic cerebral injury in the early stage. The severer the cerebral injury is, the higher the level of AVP is, which indicates that the level of AVP may be one of the severity indices of traumatic cerebral injury in elderly patients.

  4. An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion.

    Directory of Open Access Journals (Sweden)

    Adele Goldman-Pinkovich

    2016-04-01

    Full Text Available Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3, as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade.

  5. An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion.

    Science.gov (United States)

    Goldman-Pinkovich, Adele; Balno, Caitlin; Strasser, Rona; Zeituni-Molad, Michal; Bendelak, Keren; Rentsch, Doris; Ephros, Moshe; Wiese, Martin; Jardim, Armando; Myler, Peter J; Zilberstein, Dan

    2016-04-01

    Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade. PMID:27043018

  6. Two proteins with ornithine acetyltransferase activity show different functions in Streptomyces clavuligerus: Oat2 modulates clavulanic acid biosynthesis in response to arginine.

    Science.gov (United States)

    de la Fuente, A; Martín, J F; Rodríguez-García, A; Liras, P

    2004-10-01

    The oat2 gene, located in the clavulanic acid gene cluster in Streptomyces clavuligerus, is similar to argJ, which encodes N-acetylornithine:glutamic acid acetyltransferase activity. Purified proteins obtained by expression in Escherichia coli of the argJ and oat2 genes of S. clavuligerus posses N-acetyltransferase activity. The kinetics and substrate specificities of both proteins are very similar. Deletion of the oat2 gene did not affect the total N-acetylornithine transferase activity and slightly reduced the formation of clavulanic acid under standard culture conditions. However, the oat2 mutant produced more clavulanic acid than the parental strain in cultures supplemented with high levels (above 1 mM) of arginine. The purified S. clavuligerus ArgR protein bound the arginine box in the oat2 promoter, and the expression of oat2 was higher in mutants with a disruption in argR (arginine-deregulated), confirming that the Arg boxes of oat2 are functional in vivo. Our results suggest that the Oat2 protein or one of its reaction products has a regulatory role that modulates clavulanic acid biosynthesis in response to high arginine concentrations. PMID:15375131

  7. Expression pattern of a nuclear encoded mitochondrial arginine-ornithine translocator gene from Arabidopsis

    OpenAIRE

    Schneider Anja; Kunze Reinhard; Wipf Daniel; Hilpert Melanie; Desimone Marcelo; Catoni Elisabetta; Flügge Ulf-Ingo; Schumacher Karin; Frommer Wolf B

    2003-01-01

    Abstract Background Arginine and citrulline serve as nitrogen storage forms, but are also involved in biosynthetic and catabolic pathways. Metabolism of arginine, citrulline and ornithine is distributed between mitochondria and cytosol. For the shuttle of intermediates between cytosol and mitochondria transporters present on the inner mitochondrial membrane are required. Yeast contains a mitochondrial translocator for ornithine and arginine, Ort1p/Arg11p. Ort1p/Arg11p is a member of the mitoc...

  8. The arginine-ornithine antiporter ArcD contributes to biological fitness of Streptococcus suis

    Directory of Open Access Journals (Sweden)

    Marcus eFulde

    2014-08-01

    Full Text Available The arginine-ornithine antiporter (ArcD is part of the Arginine Deiminase System (ADS, a catabolic, energy-providing pathway found in a variety of different bacterial species, including the porcine zoonotic pathogen Streptococcus suis. The ADS has recently been shown to play a role in the pathogenicity of S. suis, in particular in its survival in host cells. The contribution of arginine and arginine transport mediated by ArcD, however, has yet to be clarified. In the present study, we showed by experiments using [U-13C6]arginine as a tracer molecule that S. suis is auxotrophic for arginine and that bacterial growth depends on the uptake of extracellular arginine. To further study the role of ArcD in arginine metabolism, we generated an arcD-specific mutant strain and characterized its growth compared to the wild-type (WT strain, a virulent serotype 2 strain. The mutant strain showed a markedly reduced growth rate in chemically defined media supplemented with arginine when compared to the WT strain, indicating that ArcD promotes arginine uptake. To further evaluate the in vivo relevance of ArcD, we studied the intracellular bacterial survival of the arcD mutant strain in an epithelial cell culture infection model. The mutant strain was substantially attenuated, and its reduced intracellular survival rate correlated with a lower ability to neutralize the acidified environment. Based on these results, we propose that ArcD, by its function as an arginine-ornithine antiporter, is important for supplying arginine as substrate of the ADS and, thereby, contributes to biological fitness and virulence of S. suis in the host.

  9. Risk and risk reduction involving arginine intake and meat consumption in colorectal tumorigenesis and survival

    OpenAIRE

    Zell, Jason A.; Ignatenko, Natalia A.; Yerushalmi, Hagit F; Ziogas, Argyrios; Besselsen, David G; Gerner, Eugene W.; Anton-Culver, Hoda

    2007-01-01

    Elevated polyamine and nitric oxide levels (both derived from arginine) promote tumorigenesis, whereas non-steroidal anti-inflammatory drugs (NSAIDs) inhibit colorectal cancer (CRC) incidence in experimental and epidemiologic studies. We investigated dietary arginine-induced intestinal tumorigenesis and NSAID-inhibitory effects in Apc(Min/+) mice differentially expressing nitric oxide synthase-2 (Nos2). We also studied effects of estimated arginine exposures through meat consumption on tumor ...

  10. Remission of diabetes mellitus in cats cannot be predicted by the arginine stimulation test

    OpenAIRE

    Tschuor, F

    2011-01-01

    Background: Responsiveness of β-cells to arginine persists the longest during diabetes progression, making the intravenous arginine stimulation test (IVAST) a useful tool to assess residual insulin and glucagon secretion. Hypothesis: Diabetic cats with and without remission will have different arginine-induced insulin or glucagon response. Animals: 17 cats with diabetes, 7 healthy cats. Methods: Response to IVAST was assessed by calculating insulin and glucagon area under the c...

  11. Hyponatraemia in the first week of life in preterm infants. Part I. Arginine vasopressin secretion.

    OpenAIRE

    Rees, L; Brook, C G; Shaw, J C; Forsling, M L

    1984-01-01

    Continuous sequential urinary arginine vasopressin measurements in 14 preterm, ventilated infants suggest that both osmoreceptor and volume receptor systems are able to stimulate the prolonged secretion of arginine vasopressin from 26 weeks' gestation. The kidney is able to respond to arginine vasopressin stimulation from the first day of life and from 26 weeks' gestation. A maximum urine osmolality not exceeding 550 mOsm/kg was reached which varied with hydration of the infant. Excretion of ...

  12. Protective Effect of Arginine on Oxidative Stress in Transgenic Sickle Mouse Models

    OpenAIRE

    Dasgupta, Trisha; Hebbel, Robert P.; Kaul, Dhananjay K.

    2006-01-01

    Sickle cell disease (SCD) is characterized by reperfusion injury and chronic oxidative stress. Oxidative stress and hemolysis in SCD result in inactivation of nitric oxide (NO) and depleted arginine levels. We hypothesized that augmenting NO production by arginine supplementation will reduce oxidative stress in SCD. To this end, we measured the effect of arginine (5% in mouse chow) on NO metabolites (NOx), lipid peroxidation (LPO) and selected antioxidants in transgenic sickle mouse models. U...

  13. Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells

    OpenAIRE

    Stadelmann, Britta; Merino, Maria C.; Persson, Lo; Svard, Staffan G.

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the host´s production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consu...

  14. Oral Arginine Metabolism May Decrease the Risk for Dental Caries in Children

    OpenAIRE

    Nascimento, M. M.; Liu, Y.; Kalra, R.; Perry, S.; Adewumi, A.; Xu, X.; Primosch, R.E.; Burne, R A

    2013-01-01

    Arginine metabolism by oral bacteria via the arginine deiminase system (ADS) increases the local pH, which can neutralize the effects of acidification from sugar metabolism and reduce the cariogenicity of oral biofilms. To explore the relationship between oral arginine metabolism and dental caries experience in children, we measured ADS activity in oral samples from 100 children and correlated it with their caries status and type of dentition. Supragingival dental plaque was collected from to...

  15. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pistorius Elfriede K

    2007-11-01

    Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

  16. Expression and Characterization of ArgR, An Arginine Regulatory Protein in Corynebacterium crenatum

    Institute of Scientific and Technical Information of China (English)

    CHEN Xue Lan; ZHANG Bin; TANG Li; JIAO Hai Tao; XU Heng Yi; XU Feng; XU Hong; WEI Hua; XIONG Yong Hua

    2014-01-01

    Objective Corynebacterium crenatum MT, a mutant from C. crenatum AS 1.542 with a lethal argR gene, exhibits high arginine production. To confirm the effect of ArgR on arginine biosynthesis in C. crenatum, an intact argR gene from wild-type AS 1.542 was introduced into C. crenatum MT, resulting in C. crenatum MT. sp, and the changes of transcriptional levels of the arginine biosynthetic genes and arginine production were compared between the mutant strain and the recombinant strain. Methods Quantitative real-time polymerase chain reaction was employed to analyze the changes of the related genes at the transcriptional level, electrophoretic mobility shift assays were used to determine ArgR binding with the argCJBDF, argGH, and carAB promoter regions, and arginine production was determined with an automated amino acid analyzer. Results Arginine production assays showed a 69.9%reduction in arginine from 9.01±0.22 mg/mL in C. crenatum MT to 2.71±0.13 mg/mL (P Conclusion The arginine biosynthetic genes in C. crenatum are clearly controlled by the negative regulator ArgR, and intact ArgR in C. crenatum MT results in a significant descrease in arginine production.

  17. Evaluation of chemical labeling methods for identifying functional arginine residues of proteins by mass spectrometry.

    Science.gov (United States)

    Wanigasekara, Maheshika S K; Chowdhury, Saiful M

    2016-09-01

    Arginine residues undergo several kinds of post-translational modifications (PTMs). These PTMs are associated with several inflammatory diseases, such as rheumatoid arthritis, atherosclerosis, and diabetes. Mass spectrometric studies of arginine modified proteins and peptides are very important, not only to identify the reactive arginine residues but also to understand the tandem mass spectrometry behavior of these peptides for assigning the sequences unambiguously. Herein, we utilize tandem mass spectrometry to report the performance of two widely used arginine labeling reagents, 1,2-cyclohexanedione (CHD) and phenylglyoxal (PG) with several arginine containing peptides and proteins. Time course labeling studies were performed to demonstrate the selectivity of the reagents in proteins or protein digests. Structural studies on the proteins were also explored to better understand the reaction sites and position of arginine residues. We found CHD showed better labeling efficiencies compared to phenylglyoxal. Reactive arginine profiling on a purified albumin protein clearly pointed out the cellular glycation modification site for this protein with high confidence. We believe these detailed mass-spectrometric studies will provide significant input to profile reactive arginine residues in large-scale studies; therefore, targeted proteomics can be performed to the short listed reactive sites for cellular arginine modifications. PMID:27543028

  18. Protein arginine methyltransferase 1 regulates herpes simplex virus replication through ICP27 RGG-box methylation

    International Nuclear Information System (INIS)

    Protein arginine methylation is involved in viral infection and replication through the modulation of diverse cellular processes including RNA metabolism, cytokine signaling, and subcellular localization. It has been suggested previously that the protein arginine methylation of the RGG-box of ICP27 is required for herpes simplex virus type-1 (HSV-1) viral replication and gene expression in vivo. However, a cellular mediator for this process has not yet been identified. In our current study, we show that the protein arginine methyltransferase 1 (PRMT1) is a cellular mediator of the arginine methylation of ICP27 RGG-box. We generated arginine substitution mutants in this domain and examined which arginine residues are required for methylation by PRMT1. R138, R148 and R150 were found to be the major sites of this methylation but additional arginine residues serving as minor methylation sites are still required to sustain the fully methylated form of ICP27 RGG. We also demonstrate that the nuclear foci-like structure formation, SRPK interactions, and RNA-binding activity of ICP27 are modulated by the arginine methylation of the ICP27 RGG-box. Furthermore, HSV-1 replication is inhibited by hypomethylation of this domain resulting from the use of general PRMT inhibitors or arginine mutations. Our data thus suggest that the PRMT1 plays a key role as a cellular regulator of HSV-1 replication through ICP27 RGG-box methylation.

  19. Dietary Arginine Requirements for Growth Are Dependent on the Rate of Citrulline Production in Mice123

    Science.gov (United States)

    Marini, Juan C; Agarwal, Umang; Didelija, Inka C

    2015-01-01

    Background: In many species, including humans, arginine is considered a semiessential amino acid because under certain conditions endogenous synthesis cannot meet its demand. The requirements of arginine for growth in mice are ill defined and seem to vary depending on the genetic background of the mice. Objective: The objective of this study was to determine the metabolic and molecular basis for the requirement of arginine in 2 mouse strains. Methods: Institute of Cancer Research (ICR) and C57BL/6 (BL6) male mice were fed arginine-free or arginine-sufficient diets (Expt. 1) or 1 of 7 diets with increasing arginine concentration (from 0- to 8-g/kg diet, Expt. 2) between day 24 and 42 of life to determine the arginine requirements for growth. Citrulline production and “de novo” arginine synthesis were measured with use of stable isotopes, and arginine requirements were determined by breakpoint analysis and enzyme expression by reverse transcriptase-polymerase chain reaction. Results: In Expt. 1, ICR mice grew at the same rate regardless of the arginine concentration of the diet (mean ± SE: 0.66 ± 0.04 g/d, P = 0.80), but BL6 mice had a reduced growth rate when fed the arginine-free diet (0.25 ± 0.02 g/d, P < 0.001) compared to the 8-g arginine/kg diet (0.46 ± 0.03 g/d). ICR mice showed at least a 2-fold greater expression (P < 0.001) of ornithine transcarbamylase (OTC) than BL6 mice, which translated into a greater rate of citrulline (25%) and arginine synthesis (49%, P < 0.002). In Expt. 2, breakpoint analysis showed that the requirement for growth of BL6 mice was met with 2.32 ± 0.39 g arginine/kg diet; for ICR mice, however, no breakpoint was found. Conclusion: Our data indicate that a reduced expression of OTC in BL6 mice translates into a reduced production of citrulline and arginine compared with ICR mice, which results in a dietary arginine requirement for growth in BL6 mice, but not in ICR mice. PMID:25855119

  20. Protein arginine methyltransferase 1 regulates herpes simplex virus replication through ICP27 RGG-box methylation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jungeun; Shin, Bongjin; Park, Eui-Soon; Yang, Sujeong; Choi, Seunga [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); BK21 Bio Brain Center, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); Kang, Misun [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); Rho, Jaerang, E-mail: jrrho@cnu.ac.kr [Department of Microbiology, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); BK21 Bio Brain Center, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of); GRAST, Chungnam National University, 220 Gung-dong, Yuseong-gu, Daejon 305-764 (Korea, Republic of)

    2010-01-01

    Protein arginine methylation is involved in viral infection and replication through the modulation of diverse cellular processes including RNA metabolism, cytokine signaling, and subcellular localization. It has been suggested previously that the protein arginine methylation of the RGG-box of ICP27 is required for herpes simplex virus type-1 (HSV-1) viral replication and gene expression in vivo. However, a cellular mediator for this process has not yet been identified. In our current study, we show that the protein arginine methyltransferase 1 (PRMT1) is a cellular mediator of the arginine methylation of ICP27 RGG-box. We generated arginine substitution mutants in this domain and examined which arginine residues are required for methylation by PRMT1. R138, R148 and R150 were found to be the major sites of this methylation but additional arginine residues serving as minor methylation sites are still required to sustain the fully methylated form of ICP27 RGG. We also demonstrate that the nuclear foci-like structure formation, SRPK interactions, and RNA-binding activity of ICP27 are modulated by the arginine methylation of the ICP27 RGG-box. Furthermore, HSV-1 replication is inhibited by hypomethylation of this domain resulting from the use of general PRMT inhibitors or arginine mutations. Our data thus suggest that the PRMT1 plays a key role as a cellular regulator of HSV-1 replication through ICP27 RGG-box methylation.

  1. Speciation of arsenic in human nail and hair from arsenic-affected area by HPLC-inductively coupled argon plasma mass spectrometry

    International Nuclear Information System (INIS)

    Nail and hair are rich in fibrous proteins, i.e., α-keratins that contain abundant cysteine residues (up to 22% in nail and 10-14% in hair). Although they are metabolically dead materials in the epidermis, the roots are highly influenced by the health status of the living beings and their analyses are used as a tool to monitor occupational and environmental exposure to toxic elements. The aims of the present study are to speciate arsenicals in human nail and hair and also to judge whether they should be used as a biomarker to arsenic (As) exposure and/or toxicity. All human fingernail and hair samples (n = 47) were collected from the As-affected area of West Bengal, India. Speciation of arsenicals in water extracts of fingernails and hair at 90 degree sign C was carried out by HPLC-inductively coupled argon plasma mass spectrometer (ICP MS). Fingernails contained iAsIII (58.6%), iAsV (21.5), MMAV (7.7), DMAIII (9.2), and DMAV (3.0), and hair contained iAsIII (60.9%), iAsV (33.2), MMAV (2.2), and DMAV (3.6). Fingernails contained DMAIII, but hair did not. The higher percentage of iAsIII both in fingernails and hair than that of iAsV suggests more affinity of iAsIII to keratin. Although all arsenicals in fingernails and hair correlate to As exposure positively, As speciation in fingernails seems to be more correlated with arsenism than that in hair. Exogenous contamination is a confounding factor for hair to consider it as a biomarker, whereas this is mostly absent in fingernails, which recommends it to be a better biomarker to arsenic exposure. DMAIII content in fingernails and DMAV contents in both fingernails and hair could be the biomarker to As exposure

  2. Synergistic myoprotection of L-arginine and adenosine in a canine model of global myocardial ischaemic reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    DU Lei; DIAN Ke; CHEN Hui-jiao; AN Qi; JIA Meng-xing; YANG Ping-liang; WANG Wei; DENG Shuo-zeng; LIU Jin

    2007-01-01

    Background Endogenous nitric oxide and adenosine increase simultaneously to keep the balance of energy demand and supply when the oxygen supply is insufficient, which suggests that nitric oxide and adenosine might exert a synergistic myoprotection during tissue hypoxia. In this study, we tested this hypothesis utilizing a canine model of prolonged global myocardial ischaemic reperfusion injury.Methods In this double blind, controlled study, the hearts of 24 anaesthetized mongrel dogs were arrested for 2 hours with aortic cross clamping and blood cardioplegia. The treatment groups were those supplemented with 2 mmol/L L-arginine (ARG), supplemented with 1 mmol/L adenosine (ADO), ARG + ADO supplemented with both, and no supplementation (control) (n=6 in each group). Haemodynamics, biochemical indices, adenosine triphosphate (ATP) content and myeloperoxidase activities of myocardium were determined to evaluate myocardial injury. Statistical comparison was performed by two way ANOVA.Results Although the requirements for inotropic supports were higher, the cardiac outputs were lower in control group than in ARG, ADO and the combination groups. Plasma cardiac troponin I levels were higher and the areas of hydropic changes were larger in control group than in ARG and ADO groups. Combination of arginine and adenosine provided further myoprotection with respect to better cardiac performance, lower release of cardiac troponin I, and smaller areas of hydropic changes compared with ARG and ADO groups. ATP content was higher, but myeloperoxidase activities of myocardium were significantly lower in the combination group than in control, ARG and ADO groups (P<0.05).Conclusions Combination of L-arginine and adenosine provides synergistic myoprotection in a canine model of global myocardial ischaemia. Thus, the combination is recommended when the heart is exposed to a prolonged ischaemia during cardiac surgery.

  3. Intravenous Selenium Modulates L-Arginine-Induced Experimental Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Jonathan Hardman

    2005-09-01

    Full Text Available Context Oxidative stress is understood to have a critical role in the development of acinar injury in experimental acute pancreatitis. We have previously demonstrated that compound multiple antioxidant therapy ameliorates end-organ damage in the intra-peritoneal L-arginine rat model. As the principal co-factor for glutathione, selenium is a key constituent of multiple antioxidant preparations. Objective The intention of this study was to investigate the effect of selenium on pancreatic and remote organ injury in a wellvalidated experimental model of acute pancreatitis. Methods Male Sprague-Dawley rats were randomly allocated to one of 3 groups (n=5/group and sacrificed at 72 hours. Acute pancreatitis was induced by 250 mg per 100 g body weight of 20% L-arginine hydrochloride in 0.15 mol/L sodium chloride. Group allocations were: Group 1, control; Group 2, acute pancreatitis; Group 3, selenium. Main outcome measures Serum amylase, anti-oxidant levels, bronchoalveolar lavage protein, lung myeloperoxidase activity, and histological assessment of pancreatic injury. Results L-arginine induced acute pancreatitis characterised by oedema, neutrophil infiltration, acinar cell degranulation and elevated serum amylase. Selenium treatment was associated with reduced pancreatic oedema and inflammatory cell infiltration. Acinar degranulation and dilatation were completely absent. A reduction in bronchoalveolar lavage protein content was also demonstrated. Conclusion Intravenous selenium given 24 hours after induction of experimental acute pancreatitis was associated with a reduction in the histological stigmata of pancreatic injury and a dramatic reduction in broncho-alveolar lavage protein content. Serum selenium fell during the course of experimental acute pancreatitis and this effect was not reversed by exogenous selenium supplementation.

  4. Ca2+- and Mg2+-ATPase activities in winter wheat root plasma membranes as affected by NaCl stress during growth

    NARCIS (Netherlands)

    Mansour, MMF; van Hasselt, PR; Kuiper, PJC

    1998-01-01

    Winter wheat seedlings were grown in Hoagland nutrient solution with or without 100 mmol/L NaCl added. Plasma membranes from root cells were prepared by aqueous polymer two phase partitioning and the stimulation of plasma membrane ATPase activity by Mg2+ and Ca2+ was investigated. The enzyme was act

  5. Detection of a novel arginine vasopression defect by dideoxy fingerprinting

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamani, M.R.S.; Phillips, J.A. III; Copeland, K.C. (Vanderbilt Univ. School of Medicine, Nashville, TN (United States) Univ. of Vermont College of Medicine, Burlington, VT (United States))

    1993-09-01

    Autosomal dominant neurohypophyseal diabetes insipidus is a familial form of diabetes insipidus. This disorder is associated with variable levels of arginine vasopressin (AVP) and diabetes insipidus of varying severity, which responds to exogenous AVP. To determine the molecular basis of autosomal dominant neurohypophyseal diabetes insipidus, the AVP genes of members of a large kindred were analyzed. A new method, called dideoxy fingerprinting, was used to detect an AVP mutation that was characterized by DNA sequencing. The novel defect found changes the last codon of the AVP signal peptide from alanine to threonine, which should perturb cleavage of mature AVP from its precursor protein and inhibit its secretion or action. 18 refs., 3 figs.

  6. Stability and resilience of oral microcosms toward acidification and Candida outgrowth by arginine supplementation.

    Science.gov (United States)

    Koopman, Jessica E; Röling, Wilfred F M; Buijs, Mark J; Sissons, Christopher H; ten Cate, Jacob M; Keijser, Bart J F; Crielaard, Wim; Zaura, Egija

    2015-02-01

    Dysbiosis induced by low pH in the oral ecosystem can lead to caries, a prevalent bacterial disease in humans. The amino acid arginine is one of the pH-elevating agents in the oral cavity. To obtain insights into the effect of arginine on oral microbial ecology, a multi-plaque "artificial mouth" (MAM) biofilm model was inoculated with saliva from a healthy volunteer and microcosms were grown for 4 weeks with 1.6 % (w/v) arginine supplement (Arginine) or without (Control), samples were taken at several time-points. A cariogenic environment was mimicked by sucrose pulsing. The bacterial composition was determined by 16S rRNA gene amplicon sequencing, the presence and amount of Candida and arginine deiminase system genes arcA and sagP by qPCR. Additionally, ammonium and short-chain fatty acid concentrations were determined. The Arginine microcosms were dominated by Streptococcus, Veillonella, and Neisseria and remained stable in time, while the composition of the Control microcosms diverged significantly in time, partially due to the presence of Megasphaera. The percentage of Candida increased 100-fold in the Control microcosms compared to the Arginine microcosms. The pH-raising effect of arginine was confirmed by the pH and ammonium results. The abundances of sagP and arcA were highest in the Arginine microcosms, while the concentration of butyrate was higher in the Control microcosms. We demonstrate that supplementation with arginine serves a health-promoting function; it enhances microcosm resilience toward acidification and suppresses outgrowth of the opportunistic pathogen Candida. Arginine facilitates stability of oral microbial communities and prevents them from becoming cariogenic. PMID:25433583

  7. Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.

    Science.gov (United States)

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W; Froberg, Karsten; Andersen, Lars B; El-Naaman, Bianca; Bugge, Anna; Nielsen, Birgit M; Heitman, Berit L

    2013-03-28

    The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature. PMID:23046689

  8. The protective effect of L-tryptophan versus alpha lipoic acid against L-arginine-induced experimental acute pancreatitis in albino rats

    Directory of Open Access Journals (Sweden)

    Lamia M. Farghaly* , Nagwan A. Sabak ** and Naglaa A. El-sherbeny

    2007-03-01

    Full Text Available Aim of the study: This study was conducted to investigate the possible protective effects of L- treptophan "a precursor of melatonin" and alpha lipoic acid against L- arginine-induced experimental acute pancreatitis in albino rats. Methods: Fourty adult male albino rats (200- 250g were randomized into 4 groups (n= 10. Group I, the control group was given 0.9% saline intraperitoneally (i.p. Group II, was given 500 mg/100g L-arginine (i.p as a single dose to induce acute pancreatitis. Group III: was given 250mg/kg L-tryptophan (i.p 30 min prior to L- arginine injection. Group IV: was given 50mg/kg alpha lipioc acid(i.p 30 min prior to L-arginine. Before scarifice, blood samples were obtained from all groups to assay serum amylase and interleukin 6. Animals were sacrificed after 6 hours. For the histopathological study, pancreatic tissue was prepared for histological (H&E, PAS histochemical ( Tween stain for lipases and immunohistochemical ( Bax stain for apoptosis techniques. Both qualitative and quantitative analyses were done to assess the degree of acinar cells affection Results: It was revealed that serum amylase and interleukin 6 in group II rose rapidly. Microscopically, severe acinar cells degeneration, interstitial edema, diffuse bleeding and inflammatory infiltration were demonstrated. These changes were markedly improved with the administration of both L- tryptophan and alpha lipoic acid. Conclusion: It was concluded that both L- tryptophan & alpha lipoic acid reduced the effects of L-arginine-induced acute pancreatitis with better protection achieved by L-tryptophan administration.

  9. Plasma dipeptidyl peptidase-IV activity in patients with type-2 diabetes mellitus correlates positively with HbAlc levels, but is not acutely affected by food intake

    DEFF Research Database (Denmark)

    Ryskjaer, Jakob; Deacon, Carolyn F.; Carr, Richard D;

    2006-01-01

    hormones are metabolized quickly by the enzyme dipeptidyl peptidase-IV (DPP-IV). It is well known that type-2 diabetic patients have an impaired incretin effect. Therefore, the aim of the present study was to investigate plasma DPP-IV activity in the fasting and the postprandial state in type-2 diabetic...... patients, DPP-IV activity was positively correlated to FPG and HbAlc and negatively to the duration of diabetes and age of the patients. No postprandial changes were seen in plasma DPP-IV activity in any of the groups. CONCLUSIONS: Plasma DPP-IVactivity increases in the fasting state and is positively...

  10. Effects of L-arginine immobilization on the anticoagulant activity and hemolytic property of polyethylene terephthalate films

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yun, E-mail: liuy@tgrc.org [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Yang Yun [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Wu Feng [Research Centre of Blood, College of Medicine, Xi' an Jiaotong University, Xi' an 710065 (China)

    2010-04-01

    Surface modification of polyethylene terephthalate (PET) films was performed with L-arginine (L-Arg) to gain an improved anticoagulant surface. The surface chemistry changes of modified films were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The in vitro anticoagulant activities of the surface-modified PET films were evaluated by blood clotting test, hemolytic test, and the measurement of clotting time including plasma recalcification time (PRT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The data of blood coagulation index (BCI) for L-arginine modified PET films (PET-Arg) was larger than that for PET at the same blood-sample contact time. The hemolysis ratio for PET-Arg was less than that for PET and within the accepted standard for biomaterials. The PRT and APTT for PET-Arg were significantly prolonged by 189 s and 25 s, respectively, compared to those for the unmodified PET. All results suggested that the currently described modification method could be a possible candidate to create antithrombogenic PET surfaces which would be useful for further medical applications.

  11. Effects of L-arginine immobilization on the anticoagulant activity and hemolytic property of polyethylene terephthalate films

    International Nuclear Information System (INIS)

    Surface modification of polyethylene terephthalate (PET) films was performed with L-arginine (L-Arg) to gain an improved anticoagulant surface. The surface chemistry changes of modified films were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The in vitro anticoagulant activities of the surface-modified PET films were evaluated by blood clotting test, hemolytic test, and the measurement of clotting time including plasma recalcification time (PRT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The data of blood coagulation index (BCI) for L-arginine modified PET films (PET-Arg) was larger than that for PET at the same blood-sample contact time. The hemolysis ratio for PET-Arg was less than that for PET and within the accepted standard for biomaterials. The PRT and APTT for PET-Arg were significantly prolonged by 189 s and 25 s, respectively, compared to those for the unmodified PET. All results suggested that the currently described modification method could be a possible candidate to create antithrombogenic PET surfaces which would be useful for further medical applications.

  12. Adverse effects associated with arginine alpha-ketoglutarate containing supplements.

    Science.gov (United States)

    Prosser, J M; Majlesi, N; Chan, G M; Olsen, D; Hoffman, R S; Nelson, L S

    2009-05-01

    The athletic performance supplement industry is a multibillion-dollar business and one popular category claims to increase nitric oxide (NO) production. We report three patients presenting to the emergency department with adverse effects. A 33-year-old man presented with palpitations, dizziness, vomiting, and syncope, after the use of NO(2) platinum. His examination and electrocardiogram (ECG) were normal. The dizziness persisted, requiring admission overnight. A 21-year-old man with palpitations and near syncope had used a "nitric oxide" supplement. He was tachycardic to 115 bpm with otherwise normal examination. Laboratory values including methemoglobin, and ECG were unremarkable. He was treated with 1 L of saline with no change in heart rate. He was admitted for observation. A 24-year-old man presented after taking NO-Xplode with palpitations and a headache. His examination, laboratory values, and ECG were normal. He was discharged. The purported active ingredient in these products is arginine alpha-ketoglutarate (AAKG), which is claimed to increase NO production by supplying the precursor L-arginine. The symptoms could be due to vasodilation from increased levels of NO, though other etiologies cannot be excluded. AAKG containing supplements may be associated with adverse effects requiring hospital admission. PMID:19755457

  13. Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

    International Nuclear Information System (INIS)

    The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

  14. Acute hypothalamic administration of L-arginine increases feed intake in rats

    OpenAIRE

    Carlos Ricardo Maneck Malfatti; Luiz Augusto da Silva; Ricardo Aparecido Pereira; Renan Garcia Michel; André Luiz Snak; Fabio Seidel dos Santos

    2015-01-01

    Objective: This study investigated the chronic (oral) and acute (hypothalamic infusion) effects of L-arginine supplementation on feed intake, body composition, and behavioral changes in rats. Methods: Twenty rats were divided into two groups treated orally for 60 days; one group received L-arginine (1 g/kg body weight) and one group received saline (1 mL/NaCl ...

  15. Facilitation of peptide fibre formation by arginine-phosphate/carboxylate interactions

    Indian Academy of Sciences (India)

    K Krishna Prasad; Sandeep Verma

    2008-01-01

    This study describes peptide fibre formation in a hexapeptide, derived from the V3 loop of HIV-1, mediated by the interactions between arginine residues and phosphate/carboxylate anions. This charge neutralization approach was further confirmed when the deletion of arginine residue from the hexapeptide sequence resulted in fibre formation, which was studied by a combination of microscopic techniques.

  16. Antibacterial action of a novel functionalized chitosan-arginine against Gram-negative bacteria.

    Science.gov (United States)

    Tang, Hong; Zhang, Peng; Kieft, Thomas L; Ryan, Shannon J; Baker, Shenda M; Wiesmann, William P; Rogelj, Snezna

    2010-07-01

    The antimicrobial activity of chitosan and chitosan derivatives has been well established. However, although several mechanisms have been proposed, the exact mode of action is still unclear. Here we report on the investigation of antibacterial activity and the antibacterial mode of action of a novel water-soluble chitosan derivative, arginine-functionalized chitosan, on the Gram-negative bacteria Pseudomonas fluorescens and Escherichia coli. Two different arginine-functionalized chitosans (6% arginine-substituted and 30% arginine-substituted) each strongly inhibited P. fluorescens and E. coli growth. Time-dependent killing efficacy experiments showed that 5000 mg l(-1) of 6%- and 30%-substituted chitosan-arginine killed 2.7 logs and 4.5 logs of P. fluorescens, and 4.8 logs and 4.6 logs of E. coli in 4h, respectively. At low concentrations, the 6%-substituted chitosan-arginine was more effective in inhibiting cell growth even though the 30%-substituted chitosan-arginine appeared to be more effective in permeabilizing the cell membranes of both P. fluorescens and E. coli. Studies using fluorescent probes, 1-N-phenyl-naphthylamine (NPN), nile red (NR) and propidium iodide (PI), and field emission scanning electron microscopy (FESEM) suggest that chitosan-arginine's antibacterial activity is, at least in part, due to its interaction with the cell membrane, in which it increases membrane permeability. PMID:20060936

  17. Arginine Catabolism by Sourdough Lactic Acid Bacteria: Purification and Characterization of the Arginine Deiminase Pathway Enzymes from Lactobacillus sanfranciscensis CB1

    OpenAIRE

    De Angelis, Maria; Mariotti, Liberato; Rossi, Jone; Servili, Maurizio; Fox, Patrick F.; Rollán, Graciela; Gobbetti, Marco

    2002-01-01

    The cytoplasmic extracts of 70 strains of the most frequently isolated sourdough lactic acid bacteria were screened initially for arginine deiminase (ADI), ornithine transcarbamoylase (OTC), and carbamate kinase (CK) activities, which comprise the ADI (or arginine dihydrolase) pathway. Only obligately heterofermentative strains such as Lactobacillus sanfranciscensis CB1; Lactobacillus brevis AM1, AM8, and 10A; Lactobacillus hilgardii 51B; and Lactobacillus fructivorans DD3 and DA106 showed al...

  18. A rare disease-associated mutation in the medium-chain acyl-CoA dehydrogenase (MCAD) gene changes a conserved arginine, previously shown to be functionally essential in short-chain acyl-CoA dehydrogenase (SCAD)

    DEFF Research Database (Denmark)

    Andresen, B S; Bross, P; Jensen, T G;

    1993-01-01

    . On the basis of knowledge about the three-dimensional structure of the MCAD protein, we suggest that the mutation destroys a salt bridge between arginine28 and glutamate86, thereby affecting the formation of enzymatically active protein. Twenty-two additional families with compound heterozygous patients were...

  19. The plasma level and biomarker value of neutrophil gelatinase-associated lipocalin in critically ill patients with acute kidney injury are not affected by continuous venovenous hemofiltration and anticoagulation applied

    OpenAIRE

    Schilder, Louise; Nurmohamed, S Azam; ter Wee, Pieter M.; Paauw, Nanne J.; Girbes, Armand RJ; Beishuizen, Albertus; Beelen, Robert HJ; Groeneveld, AB Johan

    2014-01-01

    Introduction Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury (AKI), and levels reflect severity of disease in critically ill patients. However, continuous venovenous hemofiltration (CVVH) may affect plasma levels by clearance or release of NGAL by activated neutrophils in the filter, dependent on the anticoagulation regimen applied. We therefore studied handling of NGAL by CVVH in patients with AKI. Methods Immediately before initiation of CVVH, prefilt...

  20. Potentiality of application of the conductometric L-arginine biosensors for the real sample analysis

    Directory of Open Access Journals (Sweden)

    Jaffrezic-Renault N.

    2012-12-01

    Full Text Available Aim. To determine an influence of serum components on the L-arginine biosensor sensitivity and to formulate practical recommendations for its reliable analysis. Methods. The L-arginine biosensor comprised arginase and urease co-immobilized by cross-linking. Results. The biosensor specificity was investigated based on a series of representative studies (namely, through urea determination in the serum; inhibitory effect studies of mercury ions; high temperature treatment of sensors; studying the biosensor sensitivity to the serum treated by enzymes, and selectivity studies. It was found that the response of the biosensor to the serum injections was determined by high sensitivity of the L-arginine biosensor toward not only to L-arginine but also toward two other basic amino acids (L-lysine and L-histidine. Conclusions. A detailed procedure of optimization of the conductometric biosensor for L-arginine determination in blood serum has been proposed.

  1. Sequestration and metabolism of host cell arginine by the intraerythrocytic malaria parasite Plasmodium falciparum.

    Science.gov (United States)

    Cobbold, Simon A; Llinás, Manuel; Kirk, Kiaran

    2016-06-01

    Human erythrocytes have an active nitric oxide synthase, which converts arginine into citrulline and nitric oxide (NO). NO serves several important functions, including the maintenance of normal erythrocyte deformability, thereby ensuring efficient passage of the red blood cell through narrow microcapillaries. Here, we show that following invasion by the malaria parasite Plasmodium falciparum the arginine pool in the host erythrocyte compartment is sequestered and metabolized by the parasite. Arginine from the extracellular medium enters the infected cell via endogenous host cell transporters and is taken up by the intracellular parasite by a high-affinity cationic amino acid transporter at the parasite surface. Within the parasite arginine is metabolized into citrulline and ornithine. The uptake and metabolism of arginine by the parasite deprive the erythrocyte of the substrate required for NO production and may contribute to the decreased deformability of infected erythrocytes. PMID:26633083

  2. Differential effects of cranial radiation on growth hormone response to arginine and insulin infusion

    International Nuclear Information System (INIS)

    The growth hormone responses to arginine infusion and to insulin-induced hypoglycemia were studied in 13 patients with neoplastic disease after treatment with radiation and chemotherapy. Patients who received intensive cranial radiation (greater than 2,400 rads) had no response to either arginine or insulin; those who received moderate cranial radiation (greater than or equal to 2,400 rads) had GH response to arginine but not to insulin; patients receiving no cranial radiation responded to both arginine and insulin. These data support the hypothesis that GH secretion in response to arginine infusion has a different mechanism in contrast to the response to insulin-induced hypoglycemia and that the latter is more vulnerable to cranial radiation

  3. Detection of the proteins with different arginine methylation status induced by low dose irradiation

    International Nuclear Information System (INIS)

    Complete text of publication follows. Objective: The objective of this study is to detect the noble proteins that were functionally regulated by change of arginine methylation through irradiation of the low dose. The increase of the arginine methylation which is induced by low dose gamma-ray will have meaningful Introduction: Exposure of cells to low doses of radiation has well documented biological effect, but the underlying regulatory mechanisms are still poorly understood. Arginine methylation is a post translational modification that results in the formation of asymmetrical and symmetrical dimethylated arginines. Post-translational methylation of arginine residues of proteins involved in a growing number of cellular processes, including transcriptional regulation, cell signaling, RNA processing and DNA repair, biological influence. Methods: Human normal cell line Chang-liver was irradiation by gamma-ray of 0.02Gy, 0.2Gy. After irradiation, cells were incubated for 4h, 8h, 24h, and then harvested to prepare protein extracts. ASYM24(anti-dimethyl-Arginine, asymmetric) antibody was used to Western blot and immunoprecipitation. Proteins that show different degrees of intensity between the two samples were analyzed by Mass spectrometry. Results: We detected increased asymmetric arginine methylation of two proteins at 24h after a dose of 0.2Gy irradiation. The mass spectrometry identified that it is 27kDa and 73kDa proteins. The 27kDa is hypothetical protein that function does not know. The 73kDa protein is Mortalin, a member of the Heat shock 70 protein family, which correlate with the radioresistance response, control of cell proliferation and act as a chaperone. Conclusion: Low dose radiation induces the change of asymmetric arginine methylation modification of arginine residues of hypothetical protein and mortalin. We expect that increase of arginine methylation in mortarin and hypothetical protein correlates with the radioresistance, the functional study for

  4. GH-releasing peptide-2 does not stimulate arginine vasopressin secretion in healthy men.

    Science.gov (United States)

    Kamoi, Kyuzi; Minagawa, Shinichi; Kimura, Keita; Ishizawa, Masahiro; Ohara, Nobumasa; Uemura, Yasuyuki; Tsuchiya, Junpei

    2010-01-01

    Ghrelin has a stimulating effect on arginine vasopressin (AVP). However, it is not known whether GHRP-2, a synthetic ghrelin receptor agonist, also has a stimulating effect on AVP release in men. To determine whether the GHRP-2 test is useful for assessing AVP secretion, blood ACTH, GH, FSH, LH, PRL, TSH and AVP levels, as well as glucose, osmolality, sodium and hematocrit, were measured before and 15, 30, 45 and 60 min after an intravenous bolus of 100 microg GHRP-2 in 10 healthy men with and without fasting. Blood pressure was measured at 15-min intervals. AVP secretion was not stimulated by the GHRP-2 test with and without fasting. There were no significant differences in hematocrit, blood pressure and plasma osmolality before and after GFRP-2 injection, although significant (p<0.001) peak blood GH, and ACTH and PRL levels were observed 30 and 15 min after GHRP-2 injection with and without fasting, respectively, and the maximal peaks were significantly (p<0.05) higher with fasting than without fasting. These results suggest that AVP secretion is not stimulated by the GHRP-2 test both with and without fasting, though GH, ACTH and PRL levels were higher with than without fasting. PMID:19907099

  5. DYSFUNCTION OF MYOCARDIAL AND VASCULAR TAURINE TRANSPORT IN L-Nω-NITRO-ARGININE-INDUCED HYPERTENSIVE RATS

    Institute of Scientific and Technical Information of China (English)

    石彦荣; 齐永芬; 卜定方; 蒋宏峰; 王冬艳; 高霖; 庞永正; 唐朝枢

    2003-01-01

    Objective. To study the change of taurine transport, and taurine transporter (TAUT) and cysteine sulfinate decarboxylase (CSD) Mrna contents in hypertension and hypertensive cardiomegaly. Methods. Taurine content was determined with a amino acid analyser. Taurine uptakes were determined by (H)-taurine incubation. The content of TAUT and CSD Mrna levels were measured by competitive quantitative RT-PCR in myocardial and vascular tissues of L-Nω-nitro-arginine (L-NNA)-in-duced hypertensive rats. Results. After the treatment of rats with L-NNA for 28 days, myocardial and vascular taurine contents decreased by 11% and 15% (P<0.05), respectively, and plasma taurine level increased by 13%(P<0.05). Myocardil and vascular Vmax of taurine uptake reduced by 30% and 19% (P<0.05), respec-tively. Their Km of taurine uptake increased by 36% and 17% (P<0.05). Myocardial and vascular TAUT Mrna content decreased by 22% and 19% (P<0.05), respectively, but CSD Mrna content increased by 22% (P<0.05)and 30% (P<0.01), respectively. Conclusions. This study suggests that there is a decreased taurine content in myocardial and vascular tissues of L-NNA-induced hypertension rats. The decreased taurine content may result from the decreased number of TAUT on the cell membrane mainly due to the down-regulation of TAUT gene and TAUT affinity eansed by hypertension and hypertensive cardiomegaly.

  6. l-Arginine grafted alginate hydrogel beads: A novel pH-sensitive system for specific protein delivery

    Directory of Open Access Journals (Sweden)

    Mohamed S. Mohy Eldin

    2015-05-01

    Full Text Available Novel pH-sensitive hydrogels based on l-arginine grafted alginate (Arg-g-Alg hydrogel beads were synthesized and utilized as a new carrier for protein delivery (BSA in specific pH media. l-arginine was grafted onto the polysaccharide backbone of virgin alginate via amine functions. Evidences of grafting of alginate were extracted from FT-IR and thermal analysis, while the morphological structure of Arg-g-Alg hydrogel beads was investigated by SEM photographs. Factors affecting on the grafting process e.g. l-arginine concentration, reaction time, reaction temperature, reaction pH, and crosslinking conditions, have been studied. Whereas, grafting efficiency of each factor was evaluated. Grafting of alginate has improved both thermal and morphological properties of Arg-g-Alg hydrogel beads. The swelling behavior of Arg-g-Alg beads was determined as a function of pH and compared with virgin calcium alginate beads. The cumulative in vitro release profiles of BSA loaded beads were studied at different pHs for simulating the physiological environments of the gastrointestinal tract. The amount of BSA released from neat alginate beads at pH 2 was almost 15% after 5 h, while the Arg-g-Alg beads at the same conditions were clearly higher than 45%, then it increased to 90% at pH 7.2. Accordingly, grafting of alginate has improved its release profile behavior particularly in acidic media. The preliminary results clearly suggested that the Arg-g-Alg hydrogel may be a potential candidate for polymeric carrier for oral delivery of protein or drugs.

  7. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    Directory of Open Access Journals (Sweden)

    David Sabater

    2014-01-01

    rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  8. Altered sodium intake affects plasma concentrations of BNP but not proBNP in healthy individuals and patients with compensated heart failure

    DEFF Research Database (Denmark)

    Damgaard, Morten; Goetze, Jens Peter; Norsk, Peter; Gadsbøll, Niels

    2007-01-01

    AIMS: Plasma B-type natriuretic peptide (BNP) and proBNP are promising markers for treatment of heart failure (HF), but the intra-individual biological variation is high. We investigated whether changes in sodium intake and posture contribute to this variation. METHODS AND RESULTS: A total of 12...... healthy individuals and 12 patients with medically treated compensated HF were examined after 1 week of low (70 mmol [1.61 g] per day) and 1 week of high (250 mmol [5.75 g] per day) sodium intake. Plasma volume and plasma concentrations of BNP and proBNP were determined after 1 h in seated and 1 h in...... supine position. In healthy individuals, the plasma BNP concentration increased significantly on high sodium intake with a ratio (high sodium/low sodium) of 2.00 (1.32-3.03, P = 0.004). The corresponding values for HF patients were 1.69 (1.25-2.29, P = 0.003). The plasma BNP concentration changed...

  9. Plasma vasopressin response to hypertonic saline infusion to assess posterior pituitary function1

    OpenAIRE

    Baylis, P. H.; Robertson, G. L.

    1980-01-01

    Hypertonic saline was infused into 11 volunteers to osmotically stimulate vasopressin secretion. A strong positive correlation between plasma arginine vasopressin (PAVP) and plasma osmolality (Pos) was obtained, defined by the function PAVP=0.63 (Pos–284), r=+0.80, P

  10. Microwave heating of arginine yields highly fluorescent nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Philippidis, Aggelos [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser (Greece); Stefanakis, Dimitrios [University of Crete, Department of Chemistry (Greece); Anglos, Demetrios, E-mail: anglos@iesl.forth.gr [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser (Greece); Ghanotakis, Demetrios, E-mail: ghanotakis@chemistry.uoc.gr [University of Crete, Department of Chemistry (Greece)

    2013-01-15

    Brightly fluorescent nanoparticles were produced via a single-step, single-precursor procedure based on microwave heating of an aqueous solution of the amino acid arginine. Key structural and optical properties of the resulting Arg nanoparticles, Arg-dots, are reported and discussed with emphasis on the pH dependence of their fluorescence emission. The surface of the Arg-dots was functionalised through coupling to folic acid, opening up ways for connecting fluorescent nanoparticles to cancer cells. The generality and versatility of the microwave heating procedure was further demonstrated by the synthesis of different types of carbon nanoparticles, such as CE-dots, that were produced by use of citric acid and ethanolamine as precursors and compared to the Arg-dots.

  11. Microwave heating of arginine yields highly fluorescent nanoparticles

    International Nuclear Information System (INIS)

    Brightly fluorescent nanoparticles were produced via a single-step, single-precursor procedure based on microwave heating of an aqueous solution of the amino acid arginine. Key structural and optical properties of the resulting Arg nanoparticles, Arg-dots, are reported and discussed with emphasis on the pH dependence of their fluorescence emission. The surface of the Arg-dots was functionalised through coupling to folic acid, opening up ways for connecting fluorescent nanoparticles to cancer cells. The generality and versatility of the microwave heating procedure was further demonstrated by the synthesis of different types of carbon nanoparticles, such as CE-dots, that were produced by use of citric acid and ethanolamine as precursors and compared to the Arg-dots.

  12. Polymerization on the rocks: beta-amino acids and arginine

    Science.gov (United States)

    Liu, R.; Orgel, L. E.; Bada, J. L. (Principal Investigator)

    1998-01-01

    We have studied the accumulation of long oligomers of beta-amino acids on the surface of minerals using the 'polymerization on the rocks' protocol. We find that long oligopeptides of beta-glutamic acid which cannot be formed in homogeneous aqueous solution are accumulated efficiently on the surface of hydroxylapatite using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) as condensing agent. The EDAC-induced oligomerization of aspartic acid on hydroxylapatite proceeds even more efficiently. Hydroxylapatite can also facilitate the ligation of the tripeptide (glu)3. The 'polymerization on the rocks' scenario is not restricted to negatively-charged amino acids. Oligoarginines are accumulated on the surface of illite using carbonyldiimidizole (CDI) as condensing agent. We find that FeS2 catalyzes the CDI-induced oligomerization of arginine, although it does not adsorb oligoarginines. These results are relevant to the formation of polypeptides on the primitive earth.

  13. Haloarchaeal Protein Translocation via the Twin Arginine Translocation Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Pohlschroder Mechthild

    2009-02-03

    Protein transport across hydrophobic membranes that partition cellular compartments is essential in all cells. The twin arginine translocation (Tat) pathway transports proteins across the prokaryotic cytoplasmic membranes. Distinct from the universally conserved Sec pathway, which secretes unfolded proteins, the Tat machinery is unique in that it secretes proteins in a folded conformation, making it an attractive pathway for the transport and secretion of heterologously expressed proteins that are Sec-incompatible. During the past 7 years, the DOE-supported project has focused on the characterization of the diversity of bacterial and archaeal Tat substrates as well as on the characterization of the Tat pathway of a model archaeon, Haloferax volcanii, a member of the haloarchaea. We have demonstrated that H. volcanii uses this pathway to transport most of its secretome.

  14. Parenteral administration of twin-bearing ewes with L-arginine enhances the birth weight and brown fat stores in sheep

    OpenAIRE

    McCoard, Sue; Sales, Francisco; Wards, Nina; Sciascia, Quentin; Oliver, Mark; Koolaard, John; van der Linden, Danitsja

    2013-01-01

    The objective of this study was to evaluate the effects of parenteral administration of L-arginine (Arg) to well-fed twin-bearing ewes from day (d) 100 of pregnancy to birth on fetal growth, body composition and neonatal behavior. Ewes received an i.v. bolus of either 345 μmol Arg-HCl/kg bodyweight or saline solution (control) 3 times a day. At d 140 of pregnancy, Arg-supplemented and control ewes were euthanized and fetal weight and fetal organ weight recorded, and maternal and fetal plasma ...

  15. Novel Flow Cytometry Analyses of Boar Sperm Viability: Can the Addition of Whole Sperm-Rich Fraction Seminal Plasma to Frozen-Thawed Boar Sperm Affect It?

    Science.gov (United States)

    Torres, Mariana Andrade; Díaz, Rommy; Boguen, Rodrigo; Martins, Simone Maria Massami Kitamura; Ravagnani, Gisele Mouro; Leal, Diego Feitosa; Oliveira, Melissa de Lima; Muro, Bruno Bracco Donatelli; Parra, Beatriz Martins; Meirelles, Flávio Vieira; Papa, Frederico Ozanan; Dell'Aqua, José Antônio; Alvarenga, Marco Antônio; Moretti, Aníbal de Sant'Anna; Sepúlveda, Néstor; de Andrade, André Furugen Cesar

    2016-01-01

    Boar semen cryopreservation remains a challenge due to the extension of cold shock damage. Thus, many alternatives have emerged to improve the quality of frozen-thawed boar sperm. Although the use of seminal plasma arising from boar sperm-rich fraction (SP-SRF) has shown good efficacy; however, the majority of actual sperm evaluation techniques include a single or dual sperm parameter analysis, which overrates the real sperm viability. Within this context, this work was performed to introduce a sperm flow cytometry fourfold stain technique for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential. We then used the sperm flow cytometry fourfold stain technique to study the effect of SP-SRF on frozen-thawed boar sperm and further evaluated the effect of this treatment on sperm movement, tyrosine phosphorylation and fertility rate (FR). The sperm fourfold stain technique is accurate (R2 = 0.9356, p > 0.01) for simultaneous evaluation of plasma and acrosomal membrane integrity and mitochondrial membrane potential (IPIAH cells). Centrifugation pre-cryopreservation was not deleterious (p > 0.05) for any analyzed variables. Addition of SP-SRF after cryopreservation was able to improve total and progressive motility (p boar semen was cryopreserved without SP-SRF; however, it was not able to decrease tyrosine phosphorylation (p > 0.05) or improve IPIAH cells (p > 0.05). FR was not (p > 0.05) statistically increased by the addition of seminal plasma, though females inseminated with frozen-thawed boar semen plus SP-SRF did perform better than those inseminated with sperm lacking seminal plasma. Thus, we conclude that sperm fourfold stain can be used to simultaneously evaluate plasma and acrosomal membrane integrity and mitochondrial membrane potential, and the addition of SP-SRF at thawed boar semen cryopreserved in absence of SP-SRF improve its total and progressive motility. PMID:27529819

  16. Catabolism and safety of supplemental L-arginine in animals.

    Science.gov (United States)

    Wu, Zhenlong; Hou, Yongqing; Hu, Shengdi; Bazer, Fuller W; Meininger, Cynthia J; McNeal, Catherine J; Wu, Guoyao

    2016-07-01

    L-arginine (Arg) is utilized via multiple pathways to synthesize protein and low-molecular-weight bioactive substances (e.g., nitric oxide, creatine, and polyamines) with enormous physiological importance. Furthermore, Arg regulates cell signaling pathways and gene expression to improve cardiovascular function, augment insulin sensitivity, enhance lean tissue mass, and reduce obesity in humans. Despite its versatile roles, the use of Arg as a dietary supplement is limited due to the lack of data to address concerns over its safety in humans. Data from animal studies are reviewed to assess arginine catabolism and the safety of long-term Arg supplementation. The arginase pathway was responsible for catabolism of 76-85 and 81-96 % Arg in extraintestinal tissues of pigs and rats, respectively. Dietary supplementation with Arg-HCl or the Arg base [315- and 630-mg Arg/(kg BW d) for 91 d] had no adverse effects on male or female pigs. Similarly, no safety issues were observed for male or female rats receiving supplementation with 1.8- and 3.6-g Arg/(kg BW d) for at least 91 d. Intravenous administration of Arg-HCl to gestating sheep at 81 and 180 mg Arg/(kg BW d) is safe for at least 82 and 40 d, respectively. Animals fed conventional diets can well tolerate large amounts of supplemental Arg [up to 630-mg Arg/(kg BW d) in pigs or 3.6-g Arg/(kg BW d) in rats] for 91 d, which are equivalent to 573-mg Arg/(kg BW d) for humans. Collectively, these results can help guide studies to determine the safety of long-term oral administration of Arg in humans. PMID:27156062

  17. One-pot green synthesis of biocompatible arginine-stabilized magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhongjun; Zhu Hui; Wang Xiaolei; Yang Fan; Yang Xiurong, E-mail: xryang@ciac.jl.c [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022 (China)

    2009-11-18

    A green one-step approach has been developed for the synthesis of amino-functionalized magnetite nanoparticles. The synthesis was accomplished by simply mixing FeCl{sub 2} with arginine under ambient conditions. It was found that the Fe{sup 2+}/arginine molar ratio, reaction duration and temperature greatly influence the size, morphology and composition of magnetic nanoparticles. The arginine-stabilized magnetic nanoparticles were characterized by transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy techniques. The results show that the prepared nanoparticles are spherically shaped with a nearly uniform size distribution and pure magnetite phase. The presence of arginine on the magnetic nanoparticle surface has been confirmed and the amount of surface arginine varies with the Fe{sup 2+}/arginine molar ratio. The surface amine densities are calculated to be 5.60 and 7.84 {mu}mol mg{sup -1} for magnetic nanoparticles prepared at 1:1 and 1:2 Fe{sup 2+}/arginine molar ratio, respectively. The as-synthesized nanoparticles show superparamagnetic behavior at room temperature and good solubility in water. In addition, using a similar synthesis procedure, we have been able to synthesize superparamagnetic manganese and cobalt ferrite nanoparticles.

  18. One-pot green synthesis of biocompatible arginine-stabilized magnetic nanoparticles

    International Nuclear Information System (INIS)

    A green one-step approach has been developed for the synthesis of amino-functionalized magnetite nanoparticles. The synthesis was accomplished by simply mixing FeCl2 with arginine under ambient conditions. It was found that the Fe2+/arginine molar ratio, reaction duration and temperature greatly influence the size, morphology and composition of magnetic nanoparticles. The arginine-stabilized magnetic nanoparticles were characterized by transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy techniques. The results show that the prepared nanoparticles are spherically shaped with a nearly uniform size distribution and pure magnetite phase. The presence of arginine on the magnetic nanoparticle surface has been confirmed and the amount of surface arginine varies with the Fe2+/arginine molar ratio. The surface amine densities are calculated to be 5.60 and 7.84 μmol mg-1 for magnetic nanoparticles prepared at 1:1 and 1:2 Fe2+/arginine molar ratio, respectively. The as-synthesized nanoparticles show superparamagnetic behavior at room temperature and good solubility in water. In addition, using a similar synthesis procedure, we have been able to synthesize superparamagnetic manganese and cobalt ferrite nanoparticles.

  19. Different environmental temperatures affect amino acid metabolism in the eurytherm teleost Senegalese sole (Solea senegalensis Kaup, 1858) as indicated by changes in plasma metabolites.

    NARCIS (Netherlands)

    Costas, B.; Aragao, C.; Ruiz-Jarabo, I.; Vargas-Chacoff, L.; Arjona, F.J.; Mancera, J.M.; Dinis, M.T.; Conceicao, L.E.

    2012-01-01

    Senegalese sole (Solea senegalensis) is a eurytherm teleost that under natural conditions can be exposed to annual water temperature fluctuations between 12 and 26 degrees C. This study assessed the effects of temperature on sole metabolic status, in particular in what concerns plasma free amino aci

  20. The effect of L-arginine on guinea-pig and rabbit airway smooth muscle function in vitro

    OpenAIRE

    Perez A.C.; Paul W.; Harrison S.; Page C.P.; Spina D.

    1998-01-01

    We have investigated the effects of L-arginine, D-arginine and L-lysine on airway smooth muscle responsiveness to spasmogens in vitro. Both L-arginine and D-arginine (100 mM) significantly reduced the contractile potency and maximal contractile response to histamine but not to methacholine or potassium chloride in guinea-pig epithelium-denuded isolated trachea. Similarly, the contractile response to histamine was significantly reduced by L-arginine (100 mM) in rabbit epithelium-denuded isolat...

  1. Hepatic adaptation compensates inactivation of intestinal arginine biosynthesis in suckling mice.

    Directory of Open Access Journals (Sweden)

    Vincent Marion

    Full Text Available Suckling mammals, including mice, differ from adults in the abundant expression of enzymes that synthesize arginine from citrulline in their enterocytes. To investigate the importance of the small-intestinal arginine synthesis for whole-body arginine production in suckling mice, we floxed exon 13 of the argininosuccinate synthetase (Ass gene, which codes for a key enzyme in arginine biosynthesis, and specifically and completely ablated Ass in enterocytes by crossing Ass (fl and Villin-Cre mice. Unexpectedly, Ass (fl/fl /VilCre (tg/- mice showed no developmental impairments. Amino-acid fluxes across the intestine, liver, and kidneys were calculated after determining the blood flow in the portal vein, and hepatic and renal arteries (86%, 14%, and 33%, respectively, of the transhepatic blood flow in 14-day-old mice. Relative to control mice, citrulline production in the splanchnic region of Ass (fl/fl /VilCre (tg/- mice doubled, while arginine production was abolished. Furthermore, the net production of arginine and most other amino acids in the liver of suckling control mice declined to naught or even changed to consumption in Ass (fl/fl /VilCre (tg/- mice, and had, thus, become remarkably similar to that of post-weaning wild-type mice, which no longer express arginine-biosynthesizing enzymes in their small intestine. The adaptive changes in liver function were accompanied by an increased expression of genes involved in arginine metabolism (Asl, Got1, Gpt2, Glud1, Arg1, and Arg2 and transport (Slc25a13, Slc25a15, and Slc3a2, whereas no such changes were found in the intestine. Our findings suggest that the genetic premature deletion of arginine synthesis in enterocytes causes a premature induction of the post-weaning pattern of amino-acid metabolism in the liver.

  2. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate.

    Science.gov (United States)

    Pilo, Raphael; Harel, Noga; Nissan, Joseph; Levartovsky, Shifra

    2016-01-01

    The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP) crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC) or Self Adhesive Resin Cement (SARC)). Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa) were significantly higher than those for SARC (2.28 ± 0.58 MPa). The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns. PMID:27023532

  3. The Retentive Strength of Cemented Zirconium Oxide Crowns after Dentin Pretreatment with Desensitizing Paste Containing 8% Arginine and Calcium Carbonate

    Directory of Open Access Journals (Sweden)

    Raphael Pilo

    2016-03-01

    Full Text Available The effect of dentin pretreatment with Desensitizing Paste containing 8% arginine and calcium carbonate on the retention of zirconium oxide (Y-TZP crowns was tested. Forty molar teeth were mounted and prepared using a standardized protocol. Y-TZP crowns were produced using computer-aided design and computer-aided manufacturing (CAD-CAM technology. The 40 prepared teeth were either pretreated with Desensitizing Paste or not pretreated. After two weeks, each group was subdivided into two groups, cemented with either Resin Modified Glass Ionomer Cement (RMGIC or Self Adhesive Resin Cement (SARC. Prior to cementation, the surface areas of the prepared teeth were measured. After aging, the cemented crown-tooth assemblies were tested for retentive strength using a universal testing machine. The debonded surfaces of the teeth and crowns were examined microscopically at 10× magnification. Pretreating the dentin surfaces with Desensitizing Paste prior to cementation did not affect the retention of the Y-TZP crowns. The retentive values for RMGIC (3.04 ± 0.77 MPa were significantly higher than those for SARC (2.28 ± 0.58 MPa. The predominant failure modes for the RMGIC and SARC were adhesive cement-dentin and adhesive cement-crown, respectively. An 8.0% arginine and calcium carbonate in-office desensitizing paste can be safely used to reduce post-cementation sensitivity without reducing the retentive strength of Y-TZP crowns.

  4. Mechanism of Allosteric Inhibition of N-Acetyl-L-glutamate Synthase by L-Arginine*

    OpenAIRE

    Min, Li; Jin, Zhongmin; Caldovic, Ljubica; Morizono, Hiroki; Allewell, Norma M.; Tuchman, Mendel; Shi, Dashuang

    2009-01-01

    N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in l-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by l-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with l-arginine bound and in the active R-state complexed with CoA and l-glutamate. Under all of the conditions examined, the enzyme consists of two stacked ...

  5. A low-saturated-fat, low-cholesterol diet decreases plasma CETP activity and pre beta-HDL formation but does not affect cellular cholesterol efflux to plasma from type 1 diabetic patients

    NARCIS (Netherlands)

    De Vries, R; Beusekamp, BJ; Kerstens, MN; Groen, AK; Van Tol, A; Dullaart, RPF

    2005-01-01

    The aim of this study was to evaluate the effect of a low-saturated-fat, low-cholesterol diet on plasma lipopoproteins, pre beta-high density lipoprotein (HDL) formation, lecithin: cholesterol acyltransferase (LCAT), cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP)

  6. Plasmas for space propulsion

    Science.gov (United States)

    Ahedo, Eduardo

    2011-12-01

    Plasma thrusters are challenging the monopoly of chemical thrusters in space propulsion. The specific energy that can be deposited into a plasma beam is orders of magnitude larger than the specific chemical energy of known fuels. Plasma thrusters constitute a vast family of devices ranging from already commercial thrusters to incipient laboratory prototypes. Figures of merit in plasma propulsion are discussed. Plasma processes and conditions differ widely from one thruster to another, with the pre-eminence of magnetized, weakly collisional plasmas. Energy is imparted to the plasma via either energetic electron injection, biased electrodes or electromagnetic irradiation. Plasma acceleration can be electrothermal, electrostatic or electromagnetic. Plasma-wall interaction affects energy deposition and erosion of thruster elements, and thus is central for thruster efficiency and lifetime. Magnetic confinement and magnetic nozzles are present in several devices. Oscillations and turbulent transport are intrinsic to the performances of some thrusters. Several thrusters are selected in order to discuss these relevant plasma phenomena.

  7. Respiratory Mechanics and Plasma Levels of Tumor Necrosis Factor Alpha and Interleukin 6 Are Affected by Gas Humidification during Mechanical Ventilation in Dogs

    OpenAIRE

    HERNÁNDEZ-JIMÉNEZ, CLAUDIA; García-Torrentera, Rogelio; Olmos-Zúñiga, J. Raúl; Jasso-Victoria, Rogelio; Miguel O Gaxiola-Gaxiola; Baltazares-Lipp, Matilde; Gutiérrez-González, Luis H.

    2014-01-01

    The use of dry gases during mechanical ventilation has been associated with the risk of serious airway complications. The goal of the present study was to quantify the plasma levels of TNF-alpha and IL-6 and to determine the radiological, hemodynamic, gasometric, and microscopic changes in lung mechanics in dogs subjected to short-term mechanical ventilation with and without humidification of the inhaled gas. The experiment was conducted for 24 hours in 10 dogs divided into two groups: Group ...

  8. Respiratory mechanics and plasma levels of tumor necrosis factor alpha and interleukin 6 are affected by gas humidification during mechanical ventilation in dogs.

    Directory of Open Access Journals (Sweden)

    Claudia Hernández-Jiménez

    Full Text Available The use of dry gases during mechanical ventilation has been associated with the risk of serious airway complications. The goal of the present study was to quantify the plasma levels of TNF-alpha and IL-6 and to determine the radiological, hemodynamic, gasometric, and microscopic changes in lung mechanics in dogs subjected to short-term mechanical ventilation with and without humidification of the inhaled gas. The experiment was conducted for 24 hours in 10 dogs divided into two groups: Group I (n = 5, mechanical ventilation with dry oxygen dispensation, and Group II (n = 5, mechanical ventilation with oxygen dispensation using a moisture chamber. Variance analysis was used. No changes in physiological, hemodynamic, or gasometric, and radiographic constants were observed. Plasma TNF-alpha levels increased in group I, reaching a maximum 24 hours after mechanical ventilation was initiated (ANOVA p = 0.77. This increase was correlated to changes in mechanical ventilation. Plasma IL-6 levels decreased at 12 hours and increased again towards the end of the study (ANOVA p>0.05. Both groups exhibited a decrease in lung compliance and functional residual capacity values, but this was more pronounced in group I. Pplat increased in group I (ANOVA p = 0.02. Inhalation of dry gas caused histological lesions in the entire respiratory tract, including pulmonary parenchyma, to a greater extent than humidified gas. Humidification of inspired gases can attenuate damage associated with mechanical ventilation.

  9. Synthesis and evaluation of trans 3,4-cyclopropyl L-arginine analogues as isoform selective inhibitors of nitric oxide synthase.

    Science.gov (United States)

    Fishlock, Dan; Perdicakis, Basil; Montgomery, Heather J; Guillemette, J Guy; Jervis, Eric; Lajoie, Gilles A

    2003-03-20

    Four optically pure conformationally restricted L-arginine analogues syn- 1 and anti- 2 trans-3,4-cyclopropyl L-arginine, and syn- 3 and anti-trans-3,4-cyclopropyl N-(1-iminoethyl) L-ornithine 4 were synthesized. These compounds were tested as potential inhibitors against the three isoforms of nitric oxide synthase (NOS). Compound 1 was determined to be a poor substrate of NOS, while compound 2 was determined to be a poor mixed type inhibitor and did not exhibit any isoform selectivity. Syn- 3 and anti-trans-3,4-cyclopropyl N-(1-iminoethyl) L-ornithine 4 were found to be competitive inhibitors of NOS. These compounds were time dependent inhibitors of inducible NOS (iNOS), but not of neuronal NOS (nNOS) or endothelial NOS (eNOS). Compound 3 was 10- to 100-fold more potent an inhibitor than 4, exhibited a 5-fold increase in nNOS/iNOS and eNOS/iNOS selectivity over 4, and displayed tight binding characteristics against iNOS. These results indicate that the relative configuration of the cyclopropyl ring in the L-arginine analogues significantly affects their inhibitory potential and NOS isoform selectivity. PMID:12614872

  10. N-(2,4)-dinitrophenyl-L-arginine Interacts with EphB4 and Functions as an EphB4 Kinase Modulator.

    Science.gov (United States)

    Kamstra, Rhiannon L; Freywald, Andrew; Floriano, Wely B

    2015-10-01

    The erythropoietin-producing hepatocellular carcinoma receptor B4 is a receptor tyrosine kinase whose expression is preserved in various malignancies, including colon, gastric, and breast carcinoma. Hepatocellular carcinoma receptor B4 presence in tumor cells and involvement in cancer suppression makes it a potential therapeutic target for activating compounds. Moreover, modulators of its activity also have a strong potential to be used in diagnosis and therapy monitoring. We used virtual ligand screening to identify novel hepatocellular carcinoma receptor B4 kinase modulators for experimental testing. Three independent assay platforms confirmed that dinitrophenyl-L-arginine is likely to affect the kinase activity of hepatocellular carcinoma receptor B4. An enzyme-coupled spectrophotometric assay has been used to examine this possibility and may prove to be useful for assessing other novel kinase modulator candidates. Overall, our observations suggest that dinitrophenyl-L-arginine has an activating effect on hepatocellular carcinoma receptor B4 and, therefore, more efficient derivatives may have therapeutic effects in tumors where hepatocellular carcinoma receptor B4 exhibits antimalignant properties. The hepatocellular carcinoma receptor B4-activating effect is discussed with respect to previously described mechanisms, using predicted and experimental structures for docked ligands. As a novel kinase activity modulator, dinitrophenyl-L-arginine may provide new insights into molecular mechanisms by which kinases are activated or regulated, and may serve as a lead compound for the generation of novel hepatocellular carcinoma receptor B4-activating therapeutic compounds. PMID:25581780

  11. Ornithine-δ-aminotransferase is essential for Arginine Catabolism but not for Proline Biosynthesis

    Directory of Open Access Journals (Sweden)

    Stadelhofer Bettina

    2008-04-01

    Full Text Available Abstract Background Like many other plant species, Arabidopsis uses arginine (Arg as a storage and transport form of nitrogen, and proline (Pro as a compatible solute in the defence against abiotic stresses causing water deprivation. Arg catabolism produces ornithine (Orn inside mitochondria, which was discussed controversially as a precursor for Pro biosynthesis, alternative to glutamate (Glu. Results We show here that ornithine-δ-aminotransferase (δOAT, At5g46180, the enzyme converting Orn to pyrroline-5-carboxylate (P5C, is localised in mitochondria and is essential for Arg catabolism. Wildtype plants could readily catabolise supplied Arg and Orn and were able to use these amino acids as the only nitrogen source. Deletion mutants of δOAT, however, accumulated urea cycle intermediates when fed with Arg or Orn and were not able to utilize nitrogen provided as Arg or Orn. Utilisation of urea and stress induced Pro accumulation were not affected in T-DNA insertion mutants with a complete loss of δOAT expression. Conclusion Our findings indicate that δOAT feeds P5C exclusively into the catabolic branch of Pro metabolism, which yields Glu as an end product. Conversion of Orn to Glu is an essential route for recovery of nitrogen stored or transported as Arg. Pro biosynthesis occurs predominantly or exclusively via the Glu pathway in Arabidopsis and does not depend on Glu produced by Arg and Orn catabolism.

  12. Ornithine-δ-aminotransferase is essential for Arginine Catabolism but not for Proline Biosynthesis

    Science.gov (United States)

    Funck, Dietmar; Stadelhofer, Bettina; Koch, Wolfgang

    2008-01-01

    Background Like many other plant species, Arabidopsis uses arginine (Arg) as a storage and transport form of nitrogen, and proline (Pro) as a compatible solute in the defence against abiotic stresses causing water deprivation. Arg catabolism produces ornithine (Orn) inside mitochondria, which was discussed controversially as a precursor for Pro biosynthesis, alternative to glutamate (Glu). Results We show here that ornithine-δ-aminotransferase (δOAT, At5g46180), the enzyme converting Orn to pyrroline-5-carboxylate (P5C), is localised in mitochondria and is essential for Arg catabolism. Wildtype plants could readily catabolise supplied Arg and Orn and were able to use these amino acids as the only nitrogen source. Deletion mutants of δOAT, however, accumulated urea cycle intermediates when fed with Arg or Orn and were not able to utilize nitrogen provided as Arg or Orn. Utilisation of urea and stress induced Pro accumulation were not affected in T-DNA insertion mutants with a complete loss of δOAT expression. Conclusion Our findings indicate that δOAT feeds P5C exclusively into the catabolic branch of Pro metabolism, which yields Glu as an end product. Conversion of Orn to Glu is an essential route for recovery of nitrogen stored or transported as Arg. Pro biosynthesis occurs predominantly or exclusively via the Glu pathway in Arabidopsis and does not depend on Glu produced by Arg and Orn catabolism. PMID:18419821

  13. Arginine acts as an inhibitor of the biosynthesis of several mycotoxins.

    Science.gov (United States)

    Touhami, Najim; Buhl, Katharina; Schmidt-Heydt, Markus; Geisen, Rolf

    2016-10-17

    It is well known that the type and the availability of nitrogen have a great influence on the biosynthesis of certain mycotoxins. Here it is shown that some amino acids have no influence, some others strongly support and a third group inhibits the biosynthesis of ochratoxin (OTA) by Penicillium nordicum even in a complex medium, such as PDA. Arginine (Arg) is one of the strong OTA inhibiting amino acids. It was shown that Arg not only inhibits OTA in Penicillium but also citrinin (CIT) biosynthesis in Penicillium verrucosum, Penicillium expansum and Penicillium citrinum and alternariol (AOH), alternariol monomethylether (AME) and tenuazonic acid (TeA) biosynthesis in Alternaria alternata. The minimal inhibitory concentration of Arg differs depending on the mycotoxin and the species analysed. However, the OTA biosynthesis by P. verrucosum and P. nordicum was most sensitive. Growth, on the other hand, was much less affected by Arg. Urea, a metabolite of Arg catabolism, shows a similar inhibitory activity. In wheat medium containing 50mM Arg almost no OTA was produced by Penicillium, in contrast to plain wheat medium. PMID:27400452

  14. Effect of L-arginine on calcium in hepatic mitochondrion in rats with obstructive jaundice

    Institute of Scientific and Technical Information of China (English)

    Mu-Sheng Lin; Hui-Lai Miao; Xiao-Guang Gong; Shi-Ting Bao

    2006-01-01

    BACKGROUND:There is much debate over the regulation of mitochondrial calcium overload and reducing the impairment of energy metabolism in hepatic cells. It has not been reported whether L-arginine (L-Arg) can affect hepatic mitochondrial calcium overload. This study was undertaken to investigate the protective effect of L-Arg on Ca2+ handling of hepatic mitochondrion in rats with obstructive jaundice and to clarify its possible mechanism. METHODS: Seventy-two male SD rats were randomly divided into 3 groups: sham operation+normal saline group (SO group), common bile duct ligation+normal saline group (BDL group), and common bile duct ligation+L-Arg group (L-Arg group). The levels of malondialdehyde (MDA), superoxide dismutase (SOD) and Ca2+ in rat hepatic mitochondrion were examined at the 7th, 14th and 21st day after operation. RESULTS: The Ca2+ and MDA levels of hepatic mitochondrion increased signiifcantly but their SOD content decreased markedly at each time point in the BDL group. Except at the 21st day, the Ca2+and MDA, contents of hepatic mitochondrion were signiifcantly lower, and SOD concentrations were higher in the L-Arg group than those in the BDL group at the 7th and 14th day (P CONCLUSION: L-Arg has a protective effect on mitochondrion in the early and mid stages of obstructive jaundice.

  15. Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

    Science.gov (United States)

    Sunatkari, A. L.; Talwatkar, S. S.; Tamgadge, Y. S.; Muley, G. G.

    2016-05-01

    We investigate the effect of L-arginine-surface passivation on localised surface plasmon resonance (LSPR), size and stability of colloidal Silver Nanoparticles (AgNPs) synthesized by chemical reduction method. The surface Plasmon resonance absorption peak of AgNPs shows blue shift with the increase in L-arginine concentration. Transmission electron microscopy (TEM) analysis confirmed that the average size of AgNPs reduces from 10 nm to 6 nm as the concentration of L-Arginine increased from 1 to 5 mM. The X-ray diffraction study (XRD) confirmed the formation face-centred cubic (fcc) structured AgNPs. FT-IR studies revealed strong bonding between L-arginine functional groups and AgNPs.

  16. Streptococcus pneumoniae arginine synthesis genes promote growth and virulence in pneumococcal meningitis

    NARCIS (Netherlands)

    J.R. Piet; M. Geldhoff; B.D.C. van Schaik; M.C. Brouwer; M. Valls Seron; M.E. Jakobs; K. Schipper; Y. Pannekoek; A.H. Zwinderman; T. van der Poll; A.H.C. van Kampen; F. Baas; A van der Ende; D. van de Beek

    2014-01-01

    Streptococcus pneumoniae (pneumococcus) is a major human pathogen causing pneumonia, sepsis and bacterial meningitis. Using a clinical phenotype based approach with bacterial whole-genome sequencing we identified pneumococcal arginine biosynthesis genes to be associated with outcome in patients with

  17. L-Arginine and L-Glutamine as Immunonutrients and Modulating Agents for Erysipelothrix rusiopathiae Infection

    Directory of Open Access Journals (Sweden)

    Haijun Wang

    2012-01-01

    Full Text Available L-arginine and L-glutamine were not only building blocks of proteins and polypeptides but also important regulators of key metabolic pathways that were necessary for maintenance, growth, reproduction and immunity in organisms. These compelling findings convinced us that L-arginine and L-glutamine play a vital role in virus and bacterium infection. However, scientific literature about its role on Erysipelothrix rhusiopathiae (E. rhusiopathiae infection was unavailable. Thus, this study was conduct to research the effect of dietary L-arginine and L-glutamine supplementation on E. rhusiopathiae infection. According to the exciting results, researchers concluded that dietary L-arginine and L-glutamine supplementation ameliorated the cytokines profile and blood parameters and delayed the development process of E. rhusiopathiae infection in mouse model.

  18. Thermal, FT–IR and SHG efficiency studies of L-arginine doped KDP crystals

    Indian Academy of Sciences (India)

    K D Parikh; D J Dave; B B Parekh; M J Joshi

    2007-04-01

    Potassium dihydrogen phosphate (KDP) is a well known nonlinear optical (NLO) material with different applications. Since most of the amino acids exhibit NLO property, it is of interest to dope them in KDP. In the present study, amino acid L-arginine was doped in KDP. The doping of L-arginine was confirmed by FT–IR and paper chromatography. Thermogravimetry suggested that as the amount of doping increases the thermal stability decreases as well as the value of thermodynamic and kinetic parameters decreases. The second harmonic generation (SHG) efficiency of L-arginine doped KDP crystals was found to be increasing with doping concentration of L-arginine. The results are discussed here.

  19. Resveratrol inhibits Trypanosoma cruzi arginine kinase and exerts a trypanocidal activity.

    Science.gov (United States)

    Valera Vera, Edward A; Sayé, Melisa; Reigada, Chantal; Damasceno, Flávia S; Silber, Ariel M; Miranda, Mariana R; Pereira, Claudio A

    2016-06-01

    Arginine kinase catalyzes the reversible transphosphorylation between ADP and phosphoarginine which plays a critical role in the maintenance of cellular energy homeostasis. Arginine kinase from the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, meets the requirements to be considered as a potential therapeutic target for rational drug design including being absent in its mammalian hosts. In this study a group of polyphenolic compounds was evaluated as potential inhibitors of arginine kinase using molecular docking techniques. Among the analyzed compounds with the lowest free binding energy to the arginine kinase active site (market price; and (3) has as a well-defined target enzyme which is absent in the mammalian host, it is a promising compound as a trypanocidal drug for Chagas disease. PMID:26976067

  20. Inhibition of corrosion of carbon steel in well water by arginine-Zn2+ system

    Directory of Open Access Journals (Sweden)

    ANTHONY SAMY SAHAYA RAJA

    2012-06-01

    Full Text Available The environmental friendly inhibitor system arginine-Zn2+, has been investigated by weight-loss method. A synergistic effect exists between arginine and Zn2+ system. The formulation consisting of 250 ppm of arginine and 5 ppm of Zn2+ offers good inhibition efficiency of 98 %. Polarization study reveals that this formulation functions as an anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal sur­face. The FTIR spectral study leads to the conclusion that the Fe2+- DL-arginine complex, formed on anodic sites of the metal surface, controls the anodic reaction. Zn(OH2 formed on the cathodic sites of the metal surface controls the cathodic reaction. The surface morphology and the roughness of the metal surface were analyzed with Atomic Force Microscope. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and surface analysis technique.

  1. Large-Scale Identification of the Arginine Methylome by Mass Spectrometry

    DEFF Research Database (Denmark)

    Sylvestersen, Kathrine B; Nielsen, Michael L

    2016-01-01

    The attachment of one or more methylation groups to the side chain of arginine residues is a regulatory mechanism for cellular proteins. Recent advances in mass spectrometry-based characterization allow comprehensive identification of arginine methylation sites by peptide-level enrichment...... strategies. Described in this unit is a 4-day protocol for enrichment of arginine-methylated peptides and subsequent identification of thousands of distinct sites by mass spectrometry. Specifically, the protocol explains step-by-step sample preparation, enrichment using commercially available antibodies......, prefractionation using strong cation exchange, and identification using liquid chromatography coupled to tandem mass spectrometry. A strategy for relative quantification is described using stable isotope labeling by amino acids in cell culture (SILAC). Approaches for analysis of arginine methylation site occupancy...

  2. Arginine does not exacerbate markers of inflammation in cocultures of human enterocytes and leukocytes

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Negrier, I.; Neveux, N.;

    2007-01-01

    Enteral arginine supplementation in the critically ill has become a matter of controversy. In this study, we investigated effects of the addition of 0.4 and 1.2 mmol/L arginine in a coculture model on markers of inflammation, enterocyte layer integrity, and amino acid transport. In this model, a...... transepithelial flux of 22 amino acids, their catabolism, and the integrity of the enterocyte layer assessed as permeability of fluorescein dextran (M(r) 4400). Bacterial stimulation of intestinal epithelial cells enhanced the basolateral concentration of nitric oxide and all cytokines measured. Supplementation...... the catabolism of serine, asparagine, and lysine, and reduced glutamine catabolism. Addition of arginine increased ornithine formation and moderately reduced transepithelial transport of methionine and other amino acids. Hence, arginine supplementation does not interfere with inflammation...

  3. Role of trypsin-like cleavage at arginine 192 in the enzymatic and cytotonic activities of Escherichia coli heat-labile enterotoxin.

    Science.gov (United States)

    Grant, C C; Messer, R J; Cieplak, W

    1994-01-01

    Previous studies of cholera toxin and Escherichia coli heat-labile enterotoxin have suggested that proteolytic cleavage plays an important role in the expression of ADP-ribosyltransferase activity and toxicity. Specifically, several studies have implicated a trypsin-like cleavage at arginine 192, which lies within an exposed region subtended by a disulfide bond in the intact A subunit, in toxicity. To investigate the role of this modification in the enzymatic and cytotonic properties of heat-labile enterotoxin, the response of purified, recombinant A subunit to tryptic activation and the effect of substituting arginine 192 with glycine on the activities of the holotoxin were examined. The recombinant A subunit of heat-labile enterotoxin exhibited significant levels of ADP-ribosyltransferase activity that were only nominally increased (approximately twofold) by prior limited trypsinolysis. The enzymatic activity also did not appear to be affected by auto-ADP-ribosylation that occurs during the high-level synthesis of the recombinant A subunit in E. coli. A mutant form of the holotoxin containing the arginine 192-to-glycine substitution exhibited levels of cytotonic activity for CHO cells that were similar to that of the untreated, wild-type holotoxin but exhibited a marked delay in the ability to increase intracellular levels of cyclic AMP in Caco-2 cells. The results indicate that trypsin-like cleavage of the A subunit of E. coli heat-labile enterotoxin at arginine 192 is not requisite to the expression of enzymatic activity by the A subunit and further reveal that this modification, although it enhances the biological and enzymatic activities of the toxin, is not absolutely required for the enterotoxin to elicit cytotonic effects. Images PMID:7927684

  4. Identification in Lupin Seed of a Serine-Endopeptidase Activity Cleaving between Twin Arginine Pairs and Causing Limited Proteolysis of Seed Storage Proteins

    Institute of Scientific and Technical Information of China (English)

    Chiara Magni; Fabio Sessa; Gabriella Tedeschi; Armando Negri; Alessio Scarafoni; Alessandro Consonni; Marcello Duranti

    2012-01-01

    The occurrence of twin-arginine motifs (-R-R-) in the amino acid sequences of animal pro-proteins frequently defines the cleavage site(s) for their structural/functional maturation.No information is available on the presence and possible biological meaning of these motifs in the seed storage proteins.In this work,a novel endopeptidase activity with cleavage specificity to twin-arginine pairs has been detected in mature dry Lupinus albus seeds.The endopeptidase was tested with a number of endogenous and exogenous protein substrates,which were selected according to the presence of one or more twin-arginine residue motifs in their amino acid sequences.The observed hydrolysis patterns were limited and highly specific.Partial proteolysis led to stable polypeptide fragments that were characterized by 1-and 2-D electrophoresis.Selected polypeptides were submitted to N-terminal amino acid sequencing and mass spectrometry analyses.These approaches,supported by bioinformatic analysis of the available sequences,allowed the conclusion that the polypeptide cleavage events had occurred at the peptide bonds comprised between twin-arginine residue pairs with all tested protein substrates.The endopeptidase activity was inhibited by 4-(2-AminoEthyl)Benzene-Sulphonyl Fluoride hydrochloride (AEBSF),leupeptin,and serine proteinase protein inhibitors,while it was not affected by pepstatin,transEpoxysuccinyI-L-leucylamido(4-guanidino)butane (E64),and ethylenediaminetetraacetic acid (EDTA),thus qualifying the Arg-Arg cleaving enzyme as a serine endopeptidase.The structural features of storage proteins from lupin and other legume seeds strongly support the hypothesis that the occurrence of an endopeptidase activity cleaving-R-R-bonds may be functional to facilitate their degradation at germination and possibly generate polypeptide fragments with specific biological activity.

  5. Tailored second line therapy in asthmatic children with the arginine-16 genotype

    OpenAIRE

    Lipworth, Brian J; Basu, Kaninika; Donald, Helen P; Tavendale, Roger; Macgregor, Donald F; Ogston, Simon A; Palmer, Colin N. A.; Mukhopadhyay, Somnath

    2012-01-01

    The arginine-16 beta-2 receptor genotype confers increased susceptibility to exacerbations in asthmatic children taking regular long acting beta-2 agonists. We therefore evaluated using montelukast as an alternative to salmeterol as tailored second line asthma controller therapy in children expressing this susceptible genotype. 62 persistent asthmatic children with the homozygous arginine-16 genotype were randomized to receive salmeterol 50ug bid or montelukast 5/10mg od as add on to inhaled ...

  6. Influence of in ovo injection of L-arginine on productive and physiological performance of quail

    Directory of Open Access Journals (Sweden)

    W. K. Al–Hayani,

    2011-07-01

    Full Text Available This study evaluated the influence of inoculation of different levels of L–arginine into eggs of 0-day-old quail embryos. On 0 day of incubation, 480 eggs (120 for each treatment group were injected with 0% arginine (C group; 1% arginine (T1; 2% arginine (T2; or 3% arginine (T3. After hatching, 336 quail chicks (84 chicks produced from each in ovo injection treatment were placed in an experimental quail house and distributed into 4 treatment groups of 3 replicates each with 16 quail chicks for each replicate. Traits determined in this study were hatchability rate, initial body weight (7 days of age, final body weight (42 days old, feed intake, weight gain, feed conversion ratio, proportional weights of carcass, breast, legs, back bone, wings, neck, abdominal fat, liver, heart, and gizzard, blood serum glucose, protein, cholesterol, total lipids, triglycerides, calcium and phosphorus and Results revealed that in ovo injection with different levels of L–arginine on 0 day of incubation resulted in significant increase (P≤0.05 in hatchability rate, initial body weight, final body weight, feed conversion ratio and serum glucose, protein, total protein, calcium, phosphorus and proportional weights of carcass, breast, legs, liver, heart, and gizzard and significant decrease (P≤0.05 in serum cholesterol, total lipids, triglycerides and proportional weight of back bone, wings and abdominal fat. In conclusion, the inoculation of different levels of L–arginine into eggs of 0–day–old quail embryos especially at the levels of 2% and 3% resulted in significant improvement in productive and physiological performance of quail. Hence in ovo injection with L–arginine could be used as a beneficial tool for enhance productive performance of quail.

  7. Arginine and pyrimidine biosynthetic defects in Neisseria gonorrhoeae strains isolated from patients.

    OpenAIRE

    Shinners, E N; Catlin, B W

    1982-01-01

    Neisseria gonorrhoeae strains with nutritional requirements that include arginine (Arg-), uracil (Ura-), and hypoxanthine have attracted attention because of their tendency to cause disseminated infections, as a basis for genetic studies of arginine and pyrimidine biosynthesis, we examined the activities of four enzymes of these pathways in cell-free extracts of both prototrophic and Arg- Ura- strains. Activities of glutamate acetyltransferase, aspartate transcarbamylase, and orotate phosphor...

  8. Arginine intake and risk of coronary heart disease mortality in elderly men

    OpenAIRE

    Oomen, C.M.; Erk, van, M.J.; Feskens, E.J.M.; Kok, F.J.; Kromhout, D.

    2000-01-01

    From experimental studies, the hypothesis is derived that the amino acid arginine, the precursor of NO, could restore the impaired endothelial function and increased platelet activation observed in atherosclerosis. We investigated whether dietary intake of arginine is associated with reduced coronary heart disease risk in elderly persons. The study population consisted of 806 men aged 64 to 84 years at baseline who participated in the Zutphen Elderly Study, a population-based cohort followed ...

  9. Structural organization of the rat gene for the arginine vasopressin-neurophysin precursor

    OpenAIRE

    Schmale, H.; Heinsohn, S; Richter, D

    1983-01-01

    The rat arginine vasopressin-neurophysin precursor gene has been isolated from a genomic library cloned in lambda phage Charon 4A. Restriction mapping and nucleotide sequence analysis demonstrated that the gene is 1.85 kilobase pairs long and contains two intervening sequences located in the protein coding region. Exon A encodes a putative signal peptide, the hormone arginine vasopressin and the variable N terminus of the carrier protein neurophysin, exon B encodes the highly conserved middle...

  10. PRE-EXERCISE ARGININE SUPPLEMENTATION INCREASES TIME TO EXHAUSTION IN ELITE MALE WRESTLERS

    OpenAIRE

    2014-01-01

    Dietary supplements containing arginine are among the most popular ergogenics intended to enhance strength, power and muscle recovery associated with both anaerobic and aerobic exercise. The aim of the present study was to evaluate the possible effect of pre-exercise acute intake of arginine on performance and exercise metabolism during incremental exhaustive exercise in elite male wrestlers. Nine volunteer elite male wrestlers (24.7±3.8 years) participated in this study. The test-retest prot...

  11. Abnormal mitochondrial L-arginine transport contributes to the pathogenesis of heart failure and rexoygenation injury.

    Directory of Open Access Journals (Sweden)

    David Williams

    Full Text Available BACKGROUND: Impaired mitochondrial function is fundamental feature of heart failure (HF and myocardial ischemia. In addition to the effects of heightened oxidative stress, altered nitric oxide (NO metabolism, generated by a mitochondrial NO synthase, has also been proposed to impact upon mitochondrial function. However, the mechanism responsible for arginine transport into mitochondria and the effect of HF on such a process is unknown. We therefore aimed to characterize mitochondrial L-arginine transport and to investigate the hypothesis that impaired mitochondrial L-arginine transport plays a key role in the pathogenesis of heart failure and myocardial injury. METHODS AND RESULTS: In mitochondria isolated from failing hearts (sheep rapid pacing model and mouse Mst1 transgenic model we demonstrated a marked reduction in L-arginine uptake (p<0.05 and p<0.01 respectively and expression of the principal L-arginine transporter, CAT-1 (p<0.001, p<0.01 compared to controls. This was accompanied by significantly lower NO production and higher 3-nitrotyrosine levels (both p<0.05. The role of mitochondrial L-arginine transport in modulating cardiac stress responses was examined in cardiomyocytes with mitochondrial specific overexpression of CAT-1 (mtCAT1 exposed to hypoxia-reoxygenation stress. mtCAT1 cardiomyocytes had significantly improved mitochondrial membrane potential, respiration and ATP turnover together with significantly decreased reactive oxygen species production and cell death following mitochondrial stress. CONCLUSION: These data provide new insights into the role of L-arginine transport in mitochondrial biology and cardiovascular disease. Augmentation of mitochondrial L-arginine availability may be a novel therapeutic strategy for myocardial disorders involving mitochondrial stress such as heart failure and reperfusion injury.

  12. Cysteine and arginine-rich peptides as molecular carriers.

    Science.gov (United States)

    Shirazi, Amir Nasrolahi; El-Sayed, Naglaa Salem; Mandal, Dindayal; Tiwari, Rakesh K; Tavakoli, Kathy; Etesham, Matthew; Parang, Keykavous

    2016-01-15

    A number of linear and cyclic peptides containing alternative arginine and cysteine residues, namely linear (CR)3, linear (CR)4, linear (CR)5, cyclic [CR]4, and cyclic [CR]5, were synthesized. The peptides were evaluated for their ability to deliver two molecular cargos, fluorescence-labeled cell-impermeable negatively charged phosphopeptide (F'-GpYEEI) and fluorescence-labeled lamivudine (F'-3TC), intracellularly in human leukemia cancer (CCRF-CEM) cells. We investigated the role of cyclization and the number of amino acids in improving the transporting ability of the peptides. The flow cytometry studies suggested that the synthesized peptides were able to work efficiently as transporters for both cargos. Among all compounds, cyclic [CR]4 was found to be the most efficient peptide in transporting the cargo into cells. For instance, the cellular uptake of F'-3TC (5μM) and F'-GpYEEI (5μM) was enhanced by 16- and 20-fold, respectively, in the presence of cyclic [CR]4 compared to that of the parent compound alone. The mechanism of F'-GpYEEI uptake by cells was found to be energy-independent. The results showed that the number of amino acids and their cyclic nature can impact the efficiency of the peptide in transporting the molecular cargos. PMID:26631317

  13. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Oscar A Cerda

    2011-01-01

    Full Text Available About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  14. Relationship of arginine with lysine in diets for laying Japanese quails

    Directory of Open Access Journals (Sweden)

    Renata de Souza Reis

    2012-01-01

    Full Text Available To determine the relationship of arginine with lysine for Japanese quails during the period of production, an experiment was conducted using 360 subspecies of Japanese quails (Coturnix coturnix japonica with 162 days of age, distributed in a completely randomized design. Diets were formulated with corn, soybean meal, sorghum and wheat bran containing 20.0% crude protein and 2,800 kcal ME/kg. The basal diet contained suboptimal level of lysine equal to 1% and was supplemented with five levels of L-arginine 99% (0.032; 0.083; 0.134; 0.185 and 0.236% to replace the glutamic acid, corresponding to the relationship of arginine with digestible lysine of 1.16, 1.21, 1.26, 1.31 and 1.36. The parameters studied were: feed intake, egg production per hen/day, egg production per hen housed, commercial egg production, egg weight, egg mass, feed conversion by egg mass, feed conversion per dozen eggs, weight and percentage of components of the eggs (yolk, albumen and shell and specific gravity. There was no significant effect on the relationship of arginine with digestible lysine in the diet of Japanese quails for any of the parameters examined. The arginine/lysine ratio of 1.16, which corresponds to a daily intake of 288.84 mg of arginine, provides satisfactory performance and egg quality of Japanese quails.

  15. Hypothalamic protein profiles associated with inhibited feed intake of ducks fed with insufficient dietary arginine.

    Science.gov (United States)

    Wang, C; Zheng, A J; Xie, M; Huang, W; Xie, J J; Hou, S S

    2014-07-01

    An experiment was conducted to investigate the effect of arginine on feed intake regulation. One hundred and twenty six 1-day-old male White Pekin ducks (Anas platyrhynchos domestica) were randomly were allotted to one of two dietary treatments. The birds were fed diets containing 0.71% (deficient) or 1.27% (sufficient) arginine for 3 weeks. At 21 days of age, feed intake was determined and hypothalamic protein profiles were analyzed using isobaric tags for relative and absolute quantification technique. The birds fed with arginine-deficient diet had a lower final live BW and cumulative feed intake (P1.5-fold expressional changes between arginine-deficient and -sufficient dietary treatments. Nine of these proteins were upregulated and seven of them were downregulated. The identified proteins could be regrouped into six categories: protein processing, carbohydrate metabolism and energy production, transporter, cytoskeleton, immunity and neuronal development. Dietary arginine deficiency decreased expression of proteins involved in energy production (glycine amidinotransferase, aldolase B fructose-bisphosphate, aconitase, transaldolase, 6-phosphofructokinase type C-like) and oxygen transportation (haemoglobin subunit α expression). The proteomic alterations described here provides valuable insights into the interactions of arginine with appetite. PMID:24804691

  16. Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

    Science.gov (United States)

    Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

    2015-11-01

    In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

  17. Early changes of arginine vasopressin and angiotensin II in patients with acute cerebral injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To study the changes and clinical significance of arginine vasopressin (AVP) and angiotensin II (AT-II) in patients with acute moderate and severe cerebral injury.   Methods: The early plasma concentration was checked by radioimmunoassay in 47 cases of acute moderate and severe cerebral injury, 30 cases of non-cerebral injury and 30 healthy volunteers.   Results: The early plasma concentrations of AVP (50.23 ng/L±15.31 ng/L) and AT-II (248.18 ng/L±82.47 ng/L) in cerebral injury group were higher than those in non-cerebral injury group (AVP for 30.91 ng/L±11.48 ng/L and AT-II for 120.67 ng/L±42.49 ng/L, P<0.01). The early plasma concentrations of AVP and AT-II in cerebral injury group were also obviously higher than those of the volunteers (AVP for 5.16 ng/L±4.23 ng/L and AT-II for 43.11 ng/L±16.39 ng/L, P<0.001). At the same time, the early plasma level of AVP (58.90 ng/L±18.12 ng/L) and AT-II (292.13 ng/L±101.17 ng/L) was higher in severe cerebral injured patients than moderate cerebral injured ones (AVP for 36.68 ng/L±12.16 ng/L and AT-II for 201.42 ng/L±66.10 ng/L, P<0.01). The early level of AVP and AT-II was negatively related to the GCS scales in acute cerebral injury. The early plasma concentrations of AVP (45.98 ng/L±13.48 ng/L) and AT-II (263.28 ng/L±80.23 ng/L) were lower in epidural hematoma group than those of subdural hematoma and cerebral injury group (AVP for 64.12 ng/L±15.56 ng/L and AT-II for 319.82 ng/L±108.11 ng/L, P<0.01).   Conclusions:  AVP and AT-II may play an important role in pathophysiologic process in the secondary cerebral injury. The more severe the cerebral injury is, the higher the early level of AVP and AT-II will be. The early plasma level of AVP and AT-II may be one of the severity indexes of cerebral injury.

  18. Plasmas for space propulsion

    International Nuclear Information System (INIS)

    Plasma thrusters are challenging the monopoly of chemical thrusters in space propulsion. The specific energy that can be deposited into a plasma beam is orders of magnitude larger than the specific chemical energy of known fuels. Plasma thrusters constitute a vast family of devices ranging from already commercial thrusters to incipient laboratory prototypes. Figures of merit in plasma propulsion are discussed. Plasma processes and conditions differ widely from one thruster to another, with the pre-eminence of magnetized, weakly collisional plasmas. Energy is imparted to the plasma via either energetic electron injection, biased electrodes or electromagnetic irradiation. Plasma acceleration can be electrothermal, electrostatic or electromagnetic. Plasma–wall interaction affects energy deposition and erosion of thruster elements, and thus is central for thruster efficiency and lifetime. Magnetic confinement and magnetic nozzles are present in several devices. Oscillations and turbulent transport are intrinsic to the performances of some thrusters. Several thrusters are selected in order to discuss these relevant plasma phenomena.

  19. Radioimmunoassay of 1-Deamino-8-D-Arginine Vasopressin and related peptides with special condsideration to their gastrointestinal absorption

    International Nuclear Information System (INIS)

    A sensitive and specific radioimminoassy for 1-deamino-8-D-arginine vasopressin (DDAVP) was developed. Measurements of the analogue in extracted and non-extracted plasma yielded indentical results, the sensitivity was reduced with non-extracted samples. The assay was validated by correlating DDAVP blood levels to a biologic response (antidiuretic). Dilutions of plasma extracts containing DDAVP were parallel with the standard curve. Fractionations of extracted plasma DDAVP samples on HPLC revealed that immunoreactivity eluted as standard DDAVP. Prolonged infusion of DDAVP in rats did not alter pituitary secretion of oxytocin and vasopressin and urine osmolatity and volume changes were modest. DDAVP was absorbed from the gastrointestinal tract of humans, rats, rabbits and dogs in quantities sufficient to induce a biological response. Peak plasma concentrations were reached between 30-90 min after peptide administration. By the use of an in vitro model, the everted rat intestine, the transmucosal passage of a number of vasopressin analogues were tested. There was no clear-cut correlation between hydrophobicity and intestinal transport rates. Metabolic inhibitors and N/sub2/ did not decrease DDAVP transport. No transport maximum could be demonstrated over a 10/sup4/ fold concentration range. The distribution volume of /sup3/H-polyethyleneglycol was greater. then that of DDAVP in mucosal flakes. There was a close correlation between immunoassayable DDAVP levels and those found after HPLC analyses. It is proposed that DDAVP absorption occurs mainly by passive diffusion. The bioavailability of perorally ingested DDAVP in humans was about 1 percent. Minor amounts were excreted in urine

  20. Cytokines Modulate the “Immune-Metabolism” Interactions during Behçet Disease: Effect on Arginine Metabolism

    Directory of Open Access Journals (Sweden)

    Houda Belguendouz

    2015-01-01

    Full Text Available Aim and Methods. In this study, we evaluated NOS and arginase activities and their regulation during Behçet disease, a systemic chronic inflammatory disorder with uncertain etiology. The peripheral blood mononuclear cells of 36 patients and 15 control samples (PBMC were cultured in either RPMI 1640, MEM, or DMEM complemented with 10% of FBS and antibiotics. Cultures were performed with or without the control or patients plasma. Subsequent treatment contained anticytokines (IL-6, TGF-β, a mitogenic effector (PHA, or NOS modulators (L-NMMA, BH4. Culture supernatants were harvested after 24 h of incubation. NO and urea measurements were, respectively, performed by modified Griess and Berthelot methods. Results. Higher urea levels were found in patients’ plasma compared to the control’s (P < 0.05. NOS modulators induced inverted production profiles for NO and urea (P < 0.05. Their results differed depending on the clinical findings (P < 0.05. It was also found that cytokine neutralization induced different response profiles in patients as opposed to control cultures (P < 0.05. Conclusion. Our results suggest that arginases can compete with NOS2 for L-arginine during Behçet disease. Both enzymes are regulated by environmental cytokines and substrate availability. Furthermore, it seems that NOS/arginase balance is dependent on clinical expression.

  1. Plasma dynamo

    CERN Document Server

    Rincon, F; Schekochihin, A A; Valentini, F

    2015-01-01

    Magnetic fields pervade the entire Universe and, through their dynamical interactions with matter, affect the formation and evolution of astrophysical systems from cosmological to planetary scales. How primordial cosmological seed fields arose and were further amplified to $\\mu$Gauss levels reported in nearby galaxy clusters, near equipartition with kinetic energy of plasma motions and on scales of at least tens of kiloparsecs, is a major theoretical puzzle still largely unconstrained by observations. Extragalactic plasmas are weakly collisional (as opposed to collisional magnetohydrodynamic fluids), and whether magnetic-field growth and its sustainment through an efficient dynamo instability driven by chaotic motions is possible in such plasmas is not known. Fully kinetic numerical simulations of the Vlasov equation in a six-dimensional phase space necessary to answer this question have until recently remained beyond computational capabilities. Here, we show by means of such simulations that magnetic-field a...

  2. Plasma metabolomics indicates metabolic perturbations in low birth weight piglets supplemented with arginine.

    Science.gov (United States)

    Getty, C M; Almeida, F N; Baratta, A A; Dilger, R N

    2015-12-01

    Large profit losses in the swine industry can be attributed to morbidity and mortality of piglets before weaning, especially in the low birth weight (LBW) piglet. Recent evidence suggests sow's milk contains insufficient concentrations of Arg to support optimal growth and health of piglets. Therefore, our objective was to assess global metabolomic profiles and the potential for Arg supplementation to promote growth of LBW (≤0.9 kg BW) and average birth weight (ABW; 1.3 to 1.5 kg BW) piglets. Piglets were selected in littermate pairs at processing to receive either Arg or an isonitrogenous control (Ala) and weighed daily to assess growth rate, and blood was collected at approximately 16 d of age for metabolomics analysis. In terms of growth, LBW and ABW piglets supplemented with Arg weighed 22.3 and 12.7% less, respectively, at d 16 compared with Ala-supplemented piglets of the same birth weight group. Overall, differences ( glucose metabolism suggested a compromised ability to extract energy from dietary sources may have occurred in the LBW piglet, but these effects were partially recovered by Arg supplementation. We conclude that a reduction in the growth potential of LBW piglets may be associated with alterations in multiple metabolic pathways, and further reduction due to Arg supplementation may have resulted from perturbations in multiple metabolic pathways. PMID:26641185

  3. Arginine-vasopressin marker copeptin is a sensitive plasma surrogate of hypoxic exposure

    OpenAIRE

    Ostergaard L; Rudiger A; Wellmann S; Gammella E; Beck-Schimmer B; Struck J.; Maggiorini M; Gassmann M

    2014-01-01

    Louise Ostergaard,1,2,* Alain Rudiger,3,* Sven Wellmann,2,4,5 Elena Gammella,6 Beatrice Beck-Schimmer,2,3 Joachim Struck,7 Marco Maggiorini,2,8 Max Gassmann,1,2,9 1Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 2Zürich Center for Integrative Human Physiology, 3Institute of Anesthesiology, 4Division of Neonatology, University Hospital Zürich, Zürich, 5Department of Neonatology, University Children's Hospital Basel, Basel, Switzerland; 6Depa...

  4. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the “L-arginine paradox”

    International Nuclear Information System (INIS)

    Highlights: ► Our findings provide a possible solution to the “L-arginine paradox”. ► Extracellular L-arginine concentration is the major determinant of NO production. ► Cellular L-arginine action is limited by cellular ARG transport, not the Km of NOS. ► We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of 15N4-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, 15N4-ARG, dimethylarginines, and L-citrulline by an LC–MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by15N-nitrite or estimated 15N3-citrulline concentrations when 15N4-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced 15N4-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by 15N-nitrite, total nitrite and 15N3-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell, ARG can no longer gain access to the membrane-bound eNOS. These observations indicate that the “L-arginine paradox” should not consider intracellular ARG concentration as a

  5. Transsulfuration pathway thiols and methylated arginines: the Hunter Community Study.

    Directory of Open Access Journals (Sweden)

    Arduino A Mangoni

    Full Text Available BACKGROUND: Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH activity] and with symmetric dimethylarginine (SDMA. We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level. METHODS: Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS, and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR = 64 (60-70 years]. RESULTS: REGRESSION ANALYSIS SHOWED THAT: a age (P = 0.001, gender (P = 0.03, lower estimated glomerular filtration rate (eGFR, P = 0.08, body mass index (P = 0.008, treatment with beta-blockers (P = 0.03, homocysteine (P = 0.02, and glutamylcysteine (P = 0.003 were independently associated with higher ADMA concentrations; and b age (P = 0.001, absence of diabetes (P = 0.001, lower body mass index (P = 0.01, lower eGFR (P<0.001, cysteine (P = 0.007, and glutamylcysteine (P < 0.001 were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations. CONCLUSIONS: After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA and/or cationic amino acid transport requires further investigations.

  6. Genes, enzymes and regulation of arginine biosynthesis in plants.

    Science.gov (United States)

    Slocum, Robert D

    2005-08-01

    Arabidopsis genes encoding enzymes for each of the eight steps in L-arginine (Arg) synthesis were identified, based upon sequence homologies with orthologs from other organisms. Except for N-acetylglutamate synthase (NAGS; EC 2.3.1.1), which is encoded by two genes, all remaining enzymes are encoded by single genes. Targeting predictions for these enzymes, based upon their deduced sequences, and subcellular fractionation studies, suggest that most enzymes of Arg synthesis reside within the plastid. Synthesis of the L-ornthine (Orn) intermediate in this pathway from L-glutamate occurs as a series of acetylated intermediates, as in most other organisms. An N-acetylornithine:glutamate acetyltransferase (NAOGAcT; EC 2.3.1.35) facilitates recycling of the acetyl moiety during Orn formation (cyclic pathway). A putative N-acetylornithine deacetylase (NAOD; EC 3.5.1.16), which participates in the "linear" pathway for Orn synthesis in some organisms, was also identified. Previous biochemical studies have indicated that allosteric regulation of the first and, especially, the second steps in Orn synthesis (NAGS; N-acetylglutamate kinase (NAGK), EC 2.7.2.8) by the Arg end-product are the major sites of metabolic control of the pathway in organisms using the cyclic pathway. Gene expression profiling for pathway enzymes further suggests that NAGS, NAGK, NAOGAcT and NAOD are coordinately regulated in response to changes in Arg demand during plant growth and development. Synthesis of Arg from Orn is further coordinated with pyrimidine nucleotide synthesis, at the level of allocation of the common carbamoyl-P intermediate. PMID:16122935

  7. Early changes of endothelin, nitric oxide and arginine-vasopressin in patients with acute cerebral injury

    Institute of Scientific and Technical Information of China (English)

    杨云梅; 黄卫东; 吕雪英

    2002-01-01

    Objective: To investigate the early changes and clinical significance of plasma endothelin (ET), nitric oxide (NO) and arginine-vasopressin (AVP) in patients with acute moderate or severe cerebral injury. Methods: The early (at 24 hours after injury) plasma concentrations of ET, NO and AVP were measured with radioimmunoassay and Green technique in 48 cases of acute moderate (GCS≤8 in 27cases ) or severe (GCS>8 in 21 cases) cerebral injury (Group A), in 42 cases of non-cerebral injury (Group B) and in 38 normal individuals (Group C), respectively. Results: The early plasma concentrations of ET (109.73 ng/L±12.61 ng/L), NO (92.82 μmol/L±18.21 μmol/L) and AVP (49.78 ng/L±14.29 ng/L) in Group A were higher than those in Group B (67.90 ng/L±11.33 ng/L, 52.66 μmol/L±12.82 μmol/L and 29.93 ng/L±12.11 ng/L, respectively, P<0.01) and Group C (50.65 ng/L±17.12 ng/L, 36.12 μmol/L±12.16 μmol/L and 5.18 ng/L±4.18 ng/L, respectively, P<0.001). The amounts of ET, NO and AVP in patients with severe cerebral injury were 116.18 ng/L±18.12 ng/L, 108.19 μmol/L±13.28 μmol/L and 58.13 ng/L±16.78 ng/L, respectively, which were significantly higher than that of the patients with moderate cerebral injury (92.33 ng/L±16.32 ng/L, 76.38 μmol/L±12.71 μmol/L and 36.18 ng/L±12.13 ng/L respectively, P<0.01). The early levels of ET, NO and AVP in Group A were negatively related to the GCS scales. The amounts of ET, NO and AVP were 126.23 ng/L±15.23 ng/L, 118.18 μmol/L±10.12 μmol/L and 63.49 ng/L±14.36 ng/L respectively in patients with subdural hematoma, which were significantly higher than those in patients with epidural hematoma (81.13 ng/L±12.37 ng/L, 68.02 μmol/L±13.18 μmol/L and 45.63 ng/L±12.41 ng/L respectively, P<0.01). The plasma concentrations of ET, NO and AVP in stable duration (at 336 hours after injury) in Group A and Group B were similar to those in Group C.Conclusions: ET, NO and AVP were related to the pathophysiological process that occurs in

  8. Arginine deiminase resistance in melanoma cells is associated with metabolic reprogramming, glucose dependence, and glutamine addiction.

    Science.gov (United States)

    Long, Yan; Tsai, Wen-Bin; Wangpaichitr, Medhi; Tsukamoto, Takashi; Savaraj, Niramol; Feun, Lynn G; Kuo, Macus Tien

    2013-11-01

    Many malignant human tumors, including melanomas, are auxotrophic for arginine due to reduced expression of argininosuccinate synthetase-1 (ASS1), the rate-limiting enzyme for arginine biosynthesis. Pegylated arginine deiminase (ADI-PEG20), which degrades extracellular arginine, resulting in arginine deprivation, has shown favorable results in clinical trials for treating arginine-auxotrophic tumors. Drug resistance is the major obstacle for effective ADI-PEG20 usage. To elucidate mechanisms of resistance, we established several ADI-PEG20-resistant (ADI(R)) variants from A2058 and SK-Mel-2 melanoma cells. Compared with the parental lines, these ADI(R) variants showed the following characteristics: (i) all ADI(R) cell lines showed elevated ASS1 expression, resulting from the constitutive binding of the transcription factor c-Myc on the ASS1 promoter, suggesting that elevated ASS1 is the major mechanism of resistance; (ii) the ADI(R) cell lines exhibited enhanced AKT signaling and were preferentially sensitive to PI3K/AKT inhibitors, but reduced mTOR signaling, and were preferentially resistant to mTOR inhibitor; (iii) these variants showed enhanced expression of glucose transporter-1 and lactate dehydrogenase-A, reduced expression of pyruvate dehydrogenase, and elevated sensitivity to the glycolytic inhibitors 2-deoxy-glucose and 3-bromopyruvate, consistent with the enhanced glycolytic pathway (the Warburg effect); (iv) the resistant cells showed higher glutamine dehydrogenase and glutaminase expression and were preferentially vulnerable to glutamine inhibitors. We showed that c-Myc, not elevated ASS1 expression, is involved in upregulation of many of these enzymes because knockdown of c-Myc reduced their expression, whereas overexpressed ASS1 by transfection reduced their expression. This study identified multiple targets for overcoming ADI-PEG resistance in cancer chemotherapy using recombinant arginine-degrading enzymes. PMID:23979920

  9. Expression pattern of a nuclear encoded mitochondrial arginine-ornithine translocator gene from Arabidopsis

    Directory of Open Access Journals (Sweden)

    Schneider Anja

    2003-01-01

    Full Text Available Abstract Background Arginine and citrulline serve as nitrogen storage forms, but are also involved in biosynthetic and catabolic pathways. Metabolism of arginine, citrulline and ornithine is distributed between mitochondria and cytosol. For the shuttle of intermediates between cytosol and mitochondria transporters present on the inner mitochondrial membrane are required. Yeast contains a mitochondrial translocator for ornithine and arginine, Ort1p/Arg11p. Ort1p/Arg11p is a member of the mitochondrial carrier family (MCF essential for ornithine export from mitochondria. The yeast arg11 mutant, which is deficient in Ort1p/Arg11p grows poorly on media lacking arginine. Results High-level expression of a nuclear encoded Arabidopsis thaliana homolog (AtmBAC2 of Ort1p/Arg11p was able to suppress the growth deficiency of arg11. RT-PCR analysis demonstrated expression of AtmBAC2 in all tissues with highest levels in flowers. Promoter-GUS fusions showed preferential expression in flowers, i.e. pollen, in the vasculature of siliques and in aborted seeds. Variable expression was observed in leaf vasculature. Induction of the promoter was not observed during the first two weeks in seedlings grown on media containing NH4NO3, arginine or ornithine as sole nitrogen sources. Conclusion AtmBAC2 was isolated as a mitochondrial transporter for arginine in Arabidopsis. The absence of expression in developing seeds and in cotyledons of seedlings indicates that other transporters are responsible for storage and mobilization of arginine in seeds.

  10. Plasma properties

    International Nuclear Information System (INIS)

    The topics of active research in the calendar year 1989 included: RF induced plasma transport, not only for its effects on the mean particle distribution function but also as a means to enhance confinement of particles and to eliminate relatively cold alpha particle ash; thorough statistical analysis of tokamak data; improved neoclassical transport analysis; deeper analysis of two-fluid Braginskii transport in a tokamak; modelling of the plasma edge and wall interaction problem; reformulation of ballooning mode stability analysis in particularly strong and general terms; MHD modelling of tokamak phenomena, such as H-mode transition, and giant sawteeth, description of highly elongated tokamaks; and analysis of edge plasma RF antenna interactions. Our basic plasma physics studies include: statistical mechanics of Coulomb gases in bounded domains; theory of MHD instabilities with flow; numerical scheme for kinetic equations with nontrivial collision operators, and heat flow in particle simulations induced by discreteness effects. In addition, there is a modest space plasma physics effort funded by non-DOE sources. The studies of heating of the solar corona are strongly affected by work from the fusion program. Equally, work on ballooning modes led to work in magnetotail instabilities and additional solar corona heating mechanisms. We except to keep some research effort in this area. We do not include in this proposal plans for any new work in this field

  11. Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

    Science.gov (United States)

    Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

    2016-01-01

    The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

  12. Effect of counter ions of arginine as an additive for the solubilization of protein and aromatic compounds.

    Science.gov (United States)

    Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2016-10-01

    Arginine is widely used in biotechnological application, but mostly with chloride counter ion. Here, we examined the effects of various anions on solubilization of aromatic compounds and reduced lysozyme and on refolding of the lysozyme. All arginine salts tested increased the solubility of propyl gallate with acetate much more effectively than chloride. The effects of arginine salts were compared with those of sodium or guanidine salts, indicating that the ability of anions to modulate the propyl gallate solubility is independent of the cation. Comparison of transfer free energy of propyl gallate between sodium and arginine salts indicates that the interaction of propyl gallate is more favorable with arginine than sodium. On the contrary, the solubility of aromatic amino acids is only slightly modulated by anions, implying that there is specific interaction between acetic acid and propyl gallate. Unlike their effects on the solubility of small aromatic compounds, the solubility of reduced lysozyme was much higher in arginine chloride than in arginine acetate or sulfate. Consistent with high solubility, refolding of reduced lysozyme was most effective in arginine chloride. These results suggest potential broader applications of arginine modulated by different anions. PMID:27234496

  13. Haplotypes in the APOA1-C3-A4-A5 gene cluster affect plasma lipids in both humans and baboons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian-fei; Liu, Xin; O' Connell, Jeff; Peng, Ze; Krauss, Ronald M.; Rainwater, David L.; VandeBerg, John L.; Rubin, Edward M.; Cheng, Jan-Fang; Pennacchio, Len A.

    2003-09-15

    Genetic studies in non-human primates serve as a potential strategy for identifying genomic intervals where polymorphisms impact upon human disease-related phenotypes. It remains unclear, however, whether independently arising polymorphisms in orthologous regions of non-human primates leads to similar variation in a quantitative trait found in both species. To explore this paradigm, we studied a baboon apolipoprotein gene cluster (APOA1/C3/A4/A5) for which the human gene orthologs have well established roles in influencing plasma HDL-cholesterol and triglyceride concentrations. Our extensive polymorphism analysis of this 68 kb gene cluster in 96 pedigreed baboons identified several haplotype blocks each with limited diversity, consistent with haplotype findings in humans. To determine whether baboons, like humans, also have particular haplotypes associated with lipid phenotypes, we genotyped 634 well characterized baboons using 16 haplotype tagging SNPs. Genetic analysis of single SNPs, as well as haplotypes, revealed an association of APOA5 and APOC3 variants with HDL cholesterol and triglyceride concentrations, respectively. Thus, independent variation in orthologous genomic intervals does associate with similar quantitative lipid traits in both species, supporting the possibility of uncovering human QTL genes in a highly controlled non-human primate model.

  14. Effect of levo-dopa, arginine and exercise on pituitary growth hormone (GH) secretion

    International Nuclear Information System (INIS)

    Objective: To assess the stimulation effect on GH secretion with different agents (levo-dopa, arginine, exercise) in dwarf subjects. Methods: Growth hormone provocative tests were performed with levo-dopa (42 times), arginine (33) and standardized exercise (35) in 78 subjects classified as dwarfs. Serum GH levels were determined with RIA before the test and several times (at 30 min, intervals) afterwards with the peak value noted. The test results were divided into 3 categories: 1) peak value 10 ng/ml, test positive (no GH deficiency). Results: Peak values of serum GH after stimulation test with respective agents were: levo-dopa 14.09 ± 9.62 ng/ml, arginine 13.77 ± 6.83 ng/ml and exercise 12.68 ± 7.81 ng/ml with no significant differences among them. Positive rate after drug stimulation was significantly higher than that after exercise: levo-dopa 35.71% (15/42), arginine 36.36% (12/33) vs exercise 14.20% (5/35) P0.05). Conclusion: Diagnosis of GH deficiency (stimulation test negative) is best established after two negative provocative tests with different stimulant each time. Levo-dopa and arginine may be the drug of choice. (authors)

  15. Mechanism of Allosteric Inhibition of N-Acetyl-L-glutamate Synthase by L-Arginine

    Energy Technology Data Exchange (ETDEWEB)

    Min, Li; Jin, Zhongmin; Caldovic, Ljubica; Morizono, Hiroki; Allewell, Norma M.; Tuchman, Mendel; Shi, Dashuang (GUW); (Maryland); (GWU); (Georgia)

    2010-01-07

    N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in L-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by L-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with L-arginine bound and in the active R-state complexed with CoA and L-glutamate. Under all of the conditions examined, the enzyme consists of two stacked trimers. Each monomer has two domains: an amino acid kinase (AAK) domain with an AAK-like fold but lacking kinase activity and an N-acetyltransferase (NAT) domain homologous to other GCN5-related transferases. Binding of L-arginine to the AAK domain induces a global conformational change that increases the diameter of the hexamer by {approx}10 {angstrom} and decreases its height by {approx}20{angstrom}. AAK dimers move 5{angstrom} outward along their 2-fold axes, and their tilt relative to the plane of the hexamer decreases by {approx}4{sup o}. The NAT domains rotate {approx}109{sup o} relative to AAK domains enabling new interdomain interactions. Interactions between AAK and NAT domains on different subunits also change. Local motions of several loops at the L-arginine-binding site enable the protein to close around the bound ligand, whereas several loops at the NAT active site become disordered, markedly reducing enzymatic specific activity.

  16. L-arginine in combination with sildenafil potentiates the attenuation of hypoxic pulmonary hypertension in rats.

    Science.gov (United States)

    Al-Hiti, H; Chovanec, M; Melenovský, V; Vajnerová, O; Baňasová, A; Kautzner, J; Herget, J

    2013-01-01

    Chronic hypoxia induces an increased production of nitric oxide (NO) in pulmonary prealveolar arterioles. Bioavailability of the NO in the pulmonary vessels correlates with concentration of L-arginine as well as activity of phosphodiesterase-5 enzyme (PDE-5). We tested a hypothesis whether a combination of L-arginine and PDE-5 inhibitor sildenafil has an additive effect in reduction of the hypoxic pulmonary hypertension (HPH) in rats. Animals were exposed to chronic normobaric hypoxia for 3 weeks. In the AH group, rats were administered L-arginine during chronic hypoxic exposure. In the SH group, rats were administered sildenafil during chronic hypoxic exposure. In the SAH group, rats were treated by the combination of L-arginine as well as sildenafil during exposure to chronic hypoxia. Mean PAP, structural remodeling of peripheral pulmonary arterioles (%DL) and RV/LV+S ratio was significantly decreased in the SAH group compared to hypoxic controls even decreased compared to the AH and the SH groups in first two measured parameters. Plasmatic concentration of cGMP and NOx were significantly lower in the SAH group compared to hypoxic controls. We demonstrate that NO synthase substrate L-arginine and phosphodiesterase-5 inhibitor sildenafil administered in combination are more potent in attenuation of the HPH compared to a treatment by substances given alone. PMID:23869884

  17. The impact of arginine-modified chitosan-DNA nanoparticles on the function of macrophages

    International Nuclear Information System (INIS)

    It has been demonstrated that incorporation of arginine moieties into chitosan significantly elevates the transgenic efficacy of the chitosan. However, little is known about the impact of arginine-modified chitosan on the function of macrophages, which play a vitally important role in the inflammatory response of the body to foreign substances, especially particulate substances. This study was designed to investigate the impact of arginine-modified chitosan/DNA nanoparticles on the function of the murine macrophage through observation of phagocytic activity and production of pro-inflammatory cytokines (IL-1β, IL-6, IL-10, IL-12, and TNF-α). Results showed that both chitosan/DNA nanoparticles and arginine-modified chitosan/DNA nanoparticles, containing 20 μg/mL DNA, were internalized by almost all the macrophages in contact. This led to no significant changes, compared to the non-exposure group, in production of cytokines and phagocytic activity of the macrophages 24 h post co-incubation, whereas exposure to LPS induced obviously elevated cytokine production and phagocytic activity, suggesting that incorporation of arginine moieties into chitosan does not have a negative impact on the function of the macrophages.

  18. Mechanism of allosteric inhibition of N-acetyl-L-glutamate synthase by L-arginine.

    Science.gov (United States)

    Min, Li; Jin, Zhongmin; Caldovic, Ljubica; Morizono, Hiroki; Allewell, Norma M; Tuchman, Mendel; Shi, Dashuang

    2009-02-20

    N-Acetylglutamate synthase (NAGS) catalyzes the first committed step in l-arginine biosynthesis in plants and micro-organisms and is subject to feedback inhibition by l-arginine. This study compares the crystal structures of NAGS from Neisseria gonorrhoeae (ngNAGS) in the inactive T-state with l-arginine bound and in the active R-state complexed with CoA and l-glutamate. Under all of the conditions examined, the enzyme consists of two stacked trimers. Each monomer has two domains: an amino acid kinase (AAK) domain with an AAK-like fold but lacking kinase activity and an N-acetyltransferase (NAT) domain homologous to other GCN5-related transferases. Binding of l-arginine to the AAK domain induces a global conformational change that increases the diameter of the hexamer by approximately 10 A and decreases its height by approximately 20A(.) AAK dimers move 5A outward along their 2-fold axes, and their tilt relative to the plane of the hexamer decreases by approximately 4 degrees . The NAT domains rotate approximately 109 degrees relative to AAK domains enabling new interdomain interactions. Interactions between AAK and NAT domains on different subunits also change. Local motions of several loops at the l-arginine-binding site enable the protein to close around the bound ligand, whereas several loops at the NAT active site become disordered, markedly reducing enzymatic specific activity. PMID:19095660

  19. L-Arginine Intake Effect on Adenine Nucleotide Metabolism in Rat Parenchymal and Reproductive Tissues

    Directory of Open Access Journals (Sweden)

    G. Kocic

    2012-01-01

    Full Text Available L-arginine is conditionally essetcial amino acid, required for normal cell growth, protein synthesis, ammonia detoxification, tissue growth and general performance, proposed in the treatment of men sterility and prevention of male impotence. The aim of the present paper was to estimate the activity of the enzymes of adenine nucleotide metabolism: 5′-nucleotidase (5′-NU, adenosine deaminase (ADA, AMP deaminase, and xanthine oxidase (XO, during dietary intake of L-arginine for a period of four weeks of male Wistar rats. Adenosine concentration in tissues is maintained by the relative activities of the adenosine-producing enzyme, 5′-NU and the adenosine-degrading enzyme-ADA adenosine deaminase. Dietary L-arginine intake directed adenine nucleotide metabolism in liver, kidney, and testis tissue toward the activation of adenosine production, by increased 5′-NU activity and decreased ADA activity. Stimulation of adenosine accumulation could be of importance in mediating arginine antiatherosclerotic, vasoactive, immunomodulatory, and antioxidant effects. Assuming that the XO activity reflects the rate of purine catabolism in the cell, while the activity of AMP deaminase is of importance in ATP regeneration, reduced activity of XO, together with the increased AMP-deaminase activity, may suggest that adenine nucleotides are presumably directed to the ATP regenerating process during dietary L-arginine intake.

  20. Arginine: A Potent Prey Attractant to Predatory Newts in Mountain Streams

    Science.gov (United States)

    Ferrer, R. P.; Zimmer, R. K.

    2005-05-01

    Chemoreception of aquatic organisms has been well-studied in the laboratory, but rarely in the field. The California newt, Taricha torosa, in natural stream habitats is an excellent animal for exploring behavioral responses to prey odors. Here, we selected 13 amino acids for field bioassays based on their concentrations in prey tissue extracts. Bioassays were calibrated for stimulus dilution by means of fluorescent dye releases and flow-through spectrofluorometry. Moreover, hydrodynamic properties of stream flows were determined using an electromagnetic current meter. Of all amino acids tested, only arginine, alanine and glycine were significantly attractive (relative to stream water controls). These three substances caused free-ranging newts to turn upstream and swim towards the odor sources. Additional experiments showed that arginine was the most effective attractant, evoking plume-tracking behavior at concentrations as low as 10 nM. In subsequent trials, nine arginine analogs were tested, but each compound failed to elicit a significant response. Even subtle changes to arginine, such as the addition of a single carbon to the side chain, destroyed all bioactivity. Within its natural habitat, the California newt thus exhibits keen sensitivity and narrow tuning to the free amino acid, arginine, a chemical signal of its prey.

  1. Biochemical and biological activity of arginine deiminase from Streptococcus pyogenes M22.

    Science.gov (United States)

    Starikova, Eleonora A; Sokolov, Alexey V; Vlasenko, Anna Yu; Burova, Larisa A; Freidlin, Irina S; Vasilyev, Vadim B

    2016-04-01

    Streptococcus pyogenes (group A Streptococcus; GAS) is an important gram-positive extracellular bacterial pathogen responsible for a number of suppurative infections. This micro-organism has developed complex virulence mechanisms to avoid the host's defenses. We have previously reported that SDSC from GAS type M22 causes endothelial-cell dysfunction, and inhibits cell adhesion, migration, metabolism, and proliferation in a dose-dependent manner, without affecting cell viability. This work aimed to isolate and characterize a component from GAS type M22 supernatant that suppresses the proliferation of endothelial cells (EA.hy926). In the process of isolating a protein possessing antiproliferative activity we identified arginine deiminase (AD). Further study showed that this enzyme is most active at pH 6.8. Calculating Km and Vmax gave the values of 0.67 mmol·L(-1) and 42 s(-1), respectively. A distinctive feature of AD purified from GAS type M22 is that its optimum activity and the maximal rate of the catalytic process is close to neutral pH by comparison with enzymes from other micro-organisms. AD from GAS type M22 suppressed the proliferative activity of endothelial cells in a dose-dependent mode. At the same time, in the presence of AD, the proportion of cells in G0/G1 phase increased. When l-Arg was added at increasing concentrations to the culture medium containing AD (3 μg·mL(-1)), the enzyme's capacity to inhibit cell proliferation became partially depressed. The proportion of cells in phases S/G2 increased concomitantly, although the cells did not fully recover their proliferation activity. This suggests that AD from GAS type M22 has potential for the suppression of excessive cell proliferation. PMID:26695833

  2. Arginine Vasopressin Is a Blood-Based Biomarker of Social Functioning in Children with Autism.

    Directory of Open Access Journals (Sweden)

    Dean S Carson

    Full Text Available Brain arginine vasopressin (AVP critically regulates normative social behavior in mammals, and experimental disruption of the AVP signaling pathway produces social impairments in rodent models. We therefore hypothesized that AVP signaling deficits may contribute to social impairments in children with autism spectrum disorder (ASD. Since blood measures (which are far easier to obtain than brain measures of AVP are most meaningful if they are related to brain AVP activity, Study 1 tested the relationship between AVP concentrations in concomitantly collected blood and CSF samples from children and adults (N = 28 undergoing clinical procedures. Study 2 tested whether blood AVP concentrations: 1 differed between children with ASD (N = 57, their ASD discordant siblings (N = 47, and neurotypical controls (N = 55; and 2 predicted social functioning (using the NEPSY-II Theory of Mind and Affect Recognition tasks and the Social Responsiveness Scale in this large, well-characterized child cohort. Blood AVP concentrations significantly and positively predicted CSF AVP concentrations (F1,26 = 7.17, r = 0.46, p = 0.0127 in Study 1. In Study 2, blood AVP concentrations did not differ between groups or by sex, but significantly and positively predicted Theory of Mind performance, specifically in children with ASD, but not in non-ASD children (F1,144 = 5.83, p = 0.017. Blood AVP concentrations can be used: 1 as a surrogate for brain AVP activity in humans; and 2 as a robust biomarker of theory of mind ability in children with ASD. These findings also suggest that AVP biology may be a promising therapeutic target by which to improve social cognition in individuals with ASD.

  3. Deletion of Genes Encoding Arginase Improves Use of "Heavy" Isotope-Labeled Arginine for Mass Spectrometry in Fission Yeast.

    Directory of Open Access Journals (Sweden)

    Weronika E Borek

    Full Text Available The use of "heavy" isotope-labeled arginine for stable isotope labeling by amino acids in cell culture (SILAC mass spectrometry in the fission yeast Schizosaccharomyces pombe is hindered by the fact that under normal conditions, arginine is extensively catabolized in vivo, resulting in the appearance of "heavy"-isotope label in several other amino acids, most notably proline, but also glutamate, glutamine and lysine. This "arginine conversion problem" significantly impairs quantification of mass spectra. Previously, we developed a method to prevent arginine conversion in fission yeast SILAC, based on deletion of genes involved in arginine catabolism. Here we show that although this method is indeed successful when (13C6-arginine (Arg-6 is used for labeling, it is less successful when (13C6(15N4-arginine (Arg-10, a theoretically preferable label, is used. In particular, we find that with this method, "heavy"-isotope label derived from Arg-10 is observed in amino acids other than arginine, indicating metabolic conversion of Arg-10. Arg-10 conversion, which severely complicates both MS and MS/MS analysis, is further confirmed by the presence of (13C5(15N2-arginine (Arg-7 in arginine-containing peptides from Arg-10-labeled cells. We describe how all of the problems associated with the use of Arg-10 can be overcome by a simple modification of our original method. We show that simultaneous deletion of the fission yeast arginase genes car1+ and aru1+ prevents virtually all of the arginine conversion that would otherwise result from the use of Arg-10. This solution should enable a wider use of heavy isotope-labeled amino acids in fission yeast SILAC.

  4. Proteomic analysis of arginine methylation sites in human cells reveals dynamic regulation during transcriptional arrest

    DEFF Research Database (Denmark)

    Sylvestersen, Kathrine B; Horn, Heiko; Jungmichel, Stephanie;

    2014-01-01

    contain regulated functions on their own. Collectively, we present a site-specific MMA dataset in human cells and demonstrate for the first time that MMA is a dynamic post-translational modification regulated during transcriptional arrest by a hitherto uncharacterized arginine demethylase....... mono-methylation (MMA) sites. We thereby identify 1,027 site-specific MMA sites on 494 human proteins, discovering numerous novel mono-methylation targets and confirming the majority of currently known MMA substrates. Nuclear RNA-binding proteins involved in RNA processing, RNA localization......, transcription, and chromatin remodeling are predominantly found modified with MMA. Despite this, MMA sites prominently are located outside RNA-binding domains as compared to the proteome-wide distribution of arginine residues. Quantification of arginine methylation in cells treated with Actinomycin D uncovers...

  5. Diagnosis of uterine and vaginal disorders by different methodologies is affected by concentration of estradiol in plasma from lactating Holstein cows.

    Science.gov (United States)

    Silper, B F; Madureira, A M L; Burnett, T A; Fernandes, A C C; Abreu, F M; Veira, D M; Vasconcelos, J L M; Cerri, R L A

    2016-06-01

    The relationship between plasma estradiol concentration at time of examination and prevalence of uterine disorders, agreement among methods, and associations of diagnosis with pregnancy hazard and milk yield was studied in 268 Holstein cows examined at 30±3 (exam 1) and 44±3 d in milk (DIM; exam 2). Purulent vaginal discharge was sampled using 2 methods: gloved hand and Metricheck (Simcro, Hamilton, New Zealand; PVD; score ≥3). Percentage of polymorphonuclear leukocytes was determined by endometrial cytology (CYTO; exam 1: ≥18%, exam 2: ≥10%); diameter of uterine horns (UTH; >20 mm), diameter of the inner layer of the cervix (CVX; >20.5 mm), presence of fluid in the uterine lumen (FL), and ovarian structures were evaluated by ultrasonography. A blood sample was collected at each exam for estradiol analysis. Prevalence at exams 1 and 2 was, respectively, 14.2 and 18.5% (PVD), 21.4 and 10.1% (FL), and 40.6 and 50.2% (CYTO). Prevalence of PVD at exam 1 was greater among cows with estradiol ≥2 pg/mL (19.4 vs. 8.2%). Agreement of all methods with CYTO was poor, the greatest being between CYTO and FL (exam 1; kappa=0.19). Agreement between CYTO and PVD, and between CYTO and FL (exam 1; kappa=0.15 and 0.35, respectively) was higher among cows with estradiol ≥2 pg/mL. Likelihood of PVD at exam 1 was greater if cows were positive for CVX [odds ratio (OR)=3.0], FL (OR=2.6) or had estradiol ≥2 pg/mL (OR=2.7). Likelihood of CYTO increased with dystocia (OR=2.3) and FL (OR=2.5). Estradiol did not influence diagnosis at exam 2. Positive FL or CYTO at exam 1 was associated with reductions in milk yield of 59 to 180 kg by 45 DIM. Pregnancy hazard until 250 DIM was reduced by CYTO at exam 1 (hazard ratio=0.74) and by PVD (hazard ratio=0.68) at exam 2. However, FL and CYTO reduced pregnancy hazard only when estradiol was ≥2 pg/mL (exam 1), whereas PVD reduced pregnancy hazard when diagnosed at exam 2 with estradiol <2 pg/mL. Overall, agreement was poor and effects of

  6. Plasma properties

    International Nuclear Information System (INIS)

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  7. GABA Production in Lactococcus lactis Is Enhanced by Arginine and Co-addition of Malate.

    Science.gov (United States)

    Laroute, Valérie; Yasaro, Chonthicha; Narin, Waranya; Mazzoli, Roberto; Pessione, Enrica; Cocaign-Bousquet, Muriel; Loubière, Pascal

    2016-01-01

    Lactococcus lactis NCDO 2118 was previously selected for its ability to decarboxylate glutamate to γ-aminobutyric acid (GABA), an interesting nutritional supplement able to improve mood and relaxation. Amino acid decarboxylation is generally considered as among the biochemical systems allowing lactic acid bacteria to counteracting acidic stress and obtaining metabolic energy. These strategies also include arginine deiminase pathway and malolactic fermentation but little is known about their possible interactions of with GABA production. In the present study, the effects of glutamate, arginine, and malate (i.e., the substrates of these acid-resistance pathways) on L. lactis NCDO 2118 growth and GABA production performances were analyzed. Both malate and arginine supplementation resulted in an efficient reduction of acidity and improvement of bacterial biomass compared to glutamate supplementation. Glutamate decarboxylation was limited to narrow environmental conditions (pH < 5.1) and physiological state (stationary phase). However, some conditions were able to improve GABA production or activate glutamate decarboxylation system even outside of this compass. Arginine clearly stimulated glutamate decarboxylation: the highest GABA production (8.6 mM) was observed in cultures supplemented with both arginine and glutamate. The simultaneous addition of arginine, malate, and glutamate enabled earlier GABA production (i.e., during exponential growth) at relatively high pH (6.5). As far as we know, no previous study has reported GABA production in such conditions. Although further studies are needed to understand the molecular basis of these phenomena, these results represent important keys suitable of application in GABA production processes. PMID:27458444

  8. Arginine-containing desensitizing toothpaste for the treatment of dentin hypersensitivity: a meta-analysis

    Science.gov (United States)

    Yang, Zheng-yan; Wang, Fei; Lu, Keke; Li, Yue-heng; Zhou, Zhi

    2016-01-01

    Objective To estimate the effect of arginine-containing desensitizing toothpaste on dentin hypersensitivity (DH). Methods Databases including China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, China Biology Medicine disc, Wangfang Data, PubMed, Web of Science, and Cochrane Trials Register were searched, and Google was used as a supplementary tool to search for information through February 2014. Randomized controlled trials (RCTs) of the treatment of DH with arginine-containing toothpaste were included. Relevant information was extracted, and a quality evaluation was performed. Meta-analyses were performed using RevMan 5.2 software. Results Eighteen RCTs with 1,423 patients were included. The results of the meta-analyses demonstrated that at days 0 and 3; weeks 2, 4, and 8; and more than 12 weeks, arginine-containing toothpaste led to significantly improved results on the tactile sensitivity test (standardized mean difference [SMD] =1.95, 95% confidence interval [CI] [1.14, 2.76]) and the air-blast test (SMD =−1.60, 95% CI [−2.14, −1.05]) at 4 weeks and the tactile sensitivity test (SMD =2.01, 95% CI [1.41, 2.61]) and the air-blast test (SMD =−1.41, 95% CI [−1.83, −0.98]) at 8 weeks compared to toothpastes containing other desensitizing components, thus indicating a superior therapeutic effect of arginine-containing desensitizing toothpaste. However, no significant differences between arginine-containing toothpaste and toothpastes containing other desensitizing components were observed in the air-blast test at days 0 and 3 and week 2 and in the tactile sensitivity and air-blast tests at more than 12 weeks. Conclusion The current evidence indicates that arginine-containing toothpaste is effective for DH. However, further high-quality, large-sample RCTs are needed. PMID:26793006

  9. Potential protective effect of arginine against 4-nitrophenol-induced ovarian damage in rats.

    Science.gov (United States)

    Xu, Wei-Feng; Li, Yan-Sen; Dai, Peng-Yuan; Li, Chun-Mei

    2016-01-01

    4-nitrophenol (PNP) is generally regarded as a diesel exhaust particle (DEP). Arginine plays an important role as a new feed additive, possessing highly efficient antioxidant activities. Here we investigated the effects of dietary supplementation with arginine against ovarian damage induced by PNP in rats. A total of thirty-two female rats postnatal day 28 (PND 28) were randomly divided into four groups. Two groups were fed with basal diet or 13 g/kg arginine in diet for 4 weeks, respectively; the other two groups were given PNP (100 mg/kg b.w.) daily by subcutaneous injection for 2 weeks following pretreatment with either basal diet or arginine diet for 2 weeks. The values of body weight gain (BWG), average daily gain (ADG) and percentage weight gain (PWG) upon PNP treatment were significantly reduced than those in other groups. The relative liver weight in the PNP group was significantly decreased compared with the control group. Treatment with PNP significant reduced the number of corpora lutea, although serum 17β-estradiol (E2) and progesterone (P4) concentrations were unchanged. The morphology of the ovaries in PNP-treated rats displayed necrosis, follicular deformation and granulosa cells irregular arrangement. Moreover, exposure to PNP enhanced production of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and decreased the activities of total superoxide dismutase (T-SOD) and catalase (CAT), and the co-administration of arginine can attenuate the oxidative stress caused by PNP. These results suggest that arginine may have a protective effect against ovarian damage induced by PNP owing to its antioxidant capacity effect. PMID:27193729

  10. Linear short histidine and cysteine modified arginine peptides constitute a potential class of DNA delivery agents.

    Science.gov (United States)

    Mann, Anita; Shukla, Vasundhara; Khanduri, Richa; Dabral, Spoorti; Singh, Harpal; Ganguli, Munia

    2014-03-01

    The success of gene therapy relies on the development of safe and efficient multifunctional carriers of nucleic acids that can overcome extra- and intracellular barriers, protect the nucleic acid and mediate its release at the desired site allowing gene expression. Peptides bear unique properties that are indispensable for any carrier, e.g., they can mediate DNA condensation, cellular targeting, membrane translocation, endosomal escape and nuclear localization. In an effort to design a multifunctional peptide, we have modified an arginine homopeptide R16 by replacement of seven arginines with histidines and addition of one cysteine at each end respectively to impart endosomal escape property while maintaining the DNA condensation and release balance. Addition of histidines imparts endosomal escape property to arginine homopeptide, but their arrangement with respect to arginines is more critical in controlling DNA condensation, release and transfection efficiency. Intriguingly, R5H7R4 peptide where charge/arginine is distributed in blocks is preferred for strong condensation while more efficient transfection is seen in the variants R9H7 and H4R9H3, which exhibit weak condensation and strong release. Addition of cysteine to each of these peptides further fine-tuned the condensation-release balance without application of any oxidative procedure unlike other similar systems reported in the literature. This resulted in a large increase in the transfection efficiency in all of the histidine modified peptides irrespective of the arginine and histidine positions. This series of multifunctional peptides shows comparable transfection efficiency to commercially available transfection reagent Lipofectamine 2000 at low charge ratios, with simple preparative procedure and exhibits much less toxicity. PMID:24476132

  11. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A

    2014-04-18

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  12. Untersuchungen zur Bedeutung von Arginin für die induzierte NO-Synthese im ZNS

    OpenAIRE

    Fischmann, Boris

    2005-01-01

    Die induzierbare NO-Synthase (iNOS) wird bei verschiedenen neurodegenerativen Erkrankungen verstärkt exprimiert und steht im Verdacht, an der Pathogenese dieser Erkrankungen beteiligt zu sein. Da Arginin der iNOS als Substrat dient, steht die induzierte NO-Produktion in engem Zusammenhang mit dem Argininstoffwechsel. In der vorliegenden Arbeit wurden in Modellsystemen für Microgliazellen (N11-Zellen) und für Astrocyten (C6-BU-1-Zellen) Aspekte der induzierten Produktion von NO und des Arginin...

  13. Effect of L-arginine on neuromuscular transmission of the chick biventer cervicis muscle

    Directory of Open Access Journals (Sweden)

    B. Esfandiar

    2008-01-01

    Full Text Available biventer cervicis muscleD. Effect of L-arginine on neuromuscular transmission of the chick EsfandiarAbstractBackground and Purpose: NO is a short-lived gas molecule generated by degradation of L-arg to citrulline and by the activation of enzyme NOS Ca2+/calmodulin-dependent. There are multiple NOS isoforms that strongly are expressed in skeletal muscle, suggesting the crucial role of NO in regulating muscular metabolism and function. In this study, the effect of L-arginine was examined at the neuromuscular junction of the chick biventer cervicis muscle.Materials and Methods: Biventer cervicis muscle preparations from chick’s age of 3 weeks were set up in the organ bath. The organ bath had a vessel with volume of about 70 ml; it contained Tyrode solution aerated with oxygen and was kept at 37º C. NO levels was also measured in the chick biventer cervicis muscle homogenates, using spectrophotometer method for the direct detection of NO, nitrite and nitrate. Total nitrite (nitrite+nitrate was measured by a spectrophotometer at 540 nm after the conversion of nitrate to nitrite by copperized cadmium granules.Results: L-Arginine at 500 µg/ml, decreased twitch response to electrical stimulation, and produced rightward shift of the dose-response curve for acetylcholine or carbachol. L-arginine at 1000 µg/ml produced a strong shift to the right of the dose-response curve for acetylcholine or carbachol with a reduction in efficacy. The inhibitory effect of L-arginine on the twitch response was blocked by caffeine (200 µg/ml. NO levels were found to be significantly increased in concentrations 500 and 1000 µg/ml of L-arginine in comparison with the control group (p < 0.001.Conclusion: These findings indicate a possible role of increased NO levels in the suppressive action of L-arginie on the twitch response. In addition, the results indicate that the post-junctional antagonistic action of L-arginine is probably the result of impaired sarcoplasmic

  14. Performance and nitrogen balance of laying hens fed increasing levels of digestible lysine and arginine

    OpenAIRE

    Fabyola Barros de Carvalho; José Henrique Stringhini; Maíra Silva Matos; Roberto Moraes Jardim Filho; Marcos Barcellos Café; Nadja Susana Mogyca Leandro; Maria Auxiliadora Andrade

    2012-01-01

    The objective of this experiment was to evaluate the effect of two digestible lysine levels and four digestible arginine levels on laying hens from 24 to 48 weeks of age. Three hundred and twenty Lohmann LSL laying hens were allotted in a completely randomized design in a 2 × 4 factorial arrangement, with two levels of digestible lysine (700 and 900 mg/kg of diet) and four digestible arginine levels (700, 800, 900 and 1000 mg/kg of diet). Results indicated requirement of 884 and 830 mg of dig...

  15. Arginine vasopressin stimulates phosphoinositide turnover in an enriched rat Leydig cell preparation

    DEFF Research Database (Denmark)

    Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

    1989-01-01

    An enriched rat Leydig cell preparation was preincubated with [C]arachidonic acid. Stimulation of the cells with arginine vasopressin (AVP) (1 µM) for 2 min caused a significant increase in labelled phosphatidic acid and a significant fall in radioactivity in phosphatidylinositol and phosphatidyl......An enriched rat Leydig cell preparation was preincubated with [C]arachidonic acid. Stimulation of the cells with arginine vasopressin (AVP) (1 µM) for 2 min caused a significant increase in labelled phosphatidic acid and a significant fall in radioactivity in phosphatidylinositol and...

  16. The Role of Arginin and Uric Acid on Portulaca Grandiflora Growth under Saline Conditions.

    OpenAIRE

    Mahmoud Yagi

    2014-01-01

    Seeds of Portulaca grandiflora were soaked in distilled water, NaCl or NaCl with uric acid or arginine or in one of the amino acids. Treatment of seeds of Portulaca grandiflora with arginine and uric acid under saline conditions increased the percent of seed germination from 55% to 80%. Incorporation of these amino acids in the nutrient medium also significantly enhanced the dry weights as well as the contents of chlorophyll and ascorbic acid in the seedlings. Levels of both total amino acids...

  17. Radiometric assay for determining the incorporation of L-canavanine or L-arginine into protein

    International Nuclear Information System (INIS)

    Procedures for a radiometric assay of L-[guanidinooxy-14C]canavanine were developed which provide a convenient and accurate measure of the incorporation of [14C]canavanine into de novo-synthesized proteins. These methods are also applicable to determining [14C]arginine incorporation into protein. These procedures have been employed to study the synthesis of L-[guanidinooxy-14C]canavanine- and L-[guanidino-14C]arginine-containing proteins from the hemolymph of Manduca sexta and Heliothis virescens, two highly destructive insect pests

  18. Reengineering of a Corynebacterium glutamicum l-Arginine and l-Citrulline Producer▿

    OpenAIRE

    Ikeda, Masato; Mitsuhashi, Satoshi; Tanaka, Kenji; Hayashi, Mikiro

    2009-01-01

    Toward the creation of a robust and efficient producer of l-arginine and l-citrulline (arginine/citrulline), we have performed reengineering of a Corynebacterium glutamicum strain by using genetic information of three classical producers. Sequence analysis of their arg operons identified three point mutations (argR123, argG92up, and argG45) in one producer and one point mutation (argB26 or argB31) in each of the other two producers. Reconstitution of the former three mutations or of each argB...

  19. Dietary l-Arginine Supplementation Protects Weanling Pigs from Deoxynivalenol-Induced Toxicity

    OpenAIRE

    Li Wu; Peng Liao; Liuqin He; Zemeng Feng; Wenkai Ren; Jie Yin; Jielin Duan; Tiejun Li; Yulong Yin

    2015-01-01

    This study was conducted to determine the positive effects of dietary supplementation with l-arginine (Arg) on piglets fed a deoxynivalenol (DON)-contaminated diet. A total of eighteen, 28-day-old healthy weanling pigs were randomly assigned into one of three groups: uncontaminated basal diet (control group), 6 mg/kg DON-contaminated diet (DON group) and 6 mg/kg DON + 1% l-arginine (DON + ARG group). After 21 days of Arg supplementation, piglets in the DON and DON + ARG groups were challenged...

  20. The microbiome, intestinal function, and arginine metabolism of healthy Indian women are different from those of American and Jamaican women

    Science.gov (United States)

    Indian women have slower arginine flux during pregnancy compared with American and Jamaican women. Arginine is a semi-essential amino acid that becomes essential during periods of rapid lean tissue deposition. It is synthesized only from citrulline, a nondietary amino acid produced mainly in the gut...

  1. Cationic amino acid transporters and Salmonella Typhimurium ArgT collectively regulate arginine availability towards intracellular Salmonella growth.

    Directory of Open Access Journals (Sweden)

    Priyanka Das

    Full Text Available Cationic amino acid transporters (mCAT1 and mCAT2B regulate the arginine availability in macrophages. How in the infected cell a pathogen can alter the arginine metabolism of the host remains to be understood. We reveal here a novel mechanism by which Salmonella exploit mCAT1 and mCAT2B to acquire host arginine towards its own intracellular growth within antigen presenting cells. We demonstrate that Salmonella infected bone marrow derived macrophages and dendritic cells show enhanced arginine uptake and increased expression of mCAT1 and mCAT2B. We show that the mCAT1 transporter is in close proximity to Salmonella containing vacuole (SCV specifically by live intracellular Salmonella in order to access the macrophage cytosolic arginine pool. Further, Lysosome associated membrane protein 1, a marker of SCV, also was found to colocalize with mCAT1 in the Salmonella infected cell. The intra vacuolar Salmonella then acquire the host arginine via its own arginine transporter, ArgT for growth. The argT knockout strain was unable to acquire host arginine and was attenuated in growth in both macrophages and in mice model of infection. Together, these data reveal survival strategies by which virulent Salmonella adapt to the harsh conditions prevailing in the infected host cells.

  2. The human neonatal small intestine has the potential for arginine synthesis; developmental changes in the expression of arginine-synthesizing and -catabolizing enzymes

    Directory of Open Access Journals (Sweden)

    Ruijter Jan M

    2008-11-01

    Full Text Available Abstract Background Milk contains too little arginine for normal growth, but its precursors proline and glutamine are abundant; the small intestine of rodents and piglets produces arginine from proline during the suckling period; and parenterally fed premature human neonates frequently suffer from hypoargininemia. These findings raise the question whether the neonatal human small intestine also expresses the enzymes that enable the synthesis of arginine from proline and/or glutamine. Carbamoylphosphate synthetase (CPS, ornithine aminotransferase (OAT, argininosuccinate synthetase (ASS, arginase-1 (ARG1, arginase-2 (ARG2, and nitric-oxide synthase (NOS were visualized by semiquantitative immunohistochemistry in 89 small-intestinal specimens. Results Between 23 weeks of gestation and 3 years after birth, CPS- and ASS-protein content in enterocytes was high and then declined to reach adult levels at 5 years. OAT levels declined more gradually, whereas ARG-1 was not expressed. ARG-2 expression increased neonatally to adult levels. Neurons in the enteric plexus strongly expressed ASS, OAT, NOS1 and ARG2, while varicose nerve fibers in the circular layer of the muscularis propria stained for ASS and NOS1 only. The endothelium of small arterioles expressed ASS and NOS3, while their smooth-muscle layer expressed OAT and ARG2. Conclusion The human small intestine acquires the potential to produce arginine well before fetuses become viable outside the uterus. The perinatal human intestine therefore resembles that of rodents and pigs. Enteral ASS behaves as a typical suckling enzyme because its expression all but disappears in the putative weaning period of human infants.

  3. DNA strand break dependence on Tris and arginine scavenger concentrations under ultra-soft X-ray irradiation: the contribution of secondary arginine radicals.

    Science.gov (United States)

    Souici, Mounir; Khalil, Talat Tariq; Boulanouar, Omar; Belafrites, Abdelfettah; Mavon, Christophe; Fromm, Michel

    2016-05-01

    In this study, we used a bench-top cold-cathode ultra-soft X-ray (USX) generator to expose aqueous DNA plasmid solutions to low-LET radiation under various scavenging conditions. Single- and double-strand breaks were assessed using classic gel electrophoresis quantification of linear, circular and supercoiled plasmid DNA topologies. With their very low penetration range in water, USX can only interact with matter up to short distances, of the order of 50 μm. We validated a stirring procedure which makes it possible to expose 100 µL of aqueous samples (2 mm thick). The scavenging of OH radicals by Tris buffer was studied at ambient temperature under aerobic conditions and compared to data gathered in the literature. A very good agreement was found with the rare data dealing with DNA plasmid exposed to Al Kα photons at low temperature (T ≤ 277 K), which therefore validated the experimental procedure. The yields for DNA single-strand breaks determined during this study enabled the ratio of indirect to direct effects to be determined at 96.2 %, in good agreement with the value of 97.7 % stemming from a study based on γ-ray irradiation of frozen solutions of plasmid DNA. Then, arginine was used both to create a "biological-like" chemical environment around the DNA plasmids and as an OH radical scavenger, in vitro. Although arginine has a greater scavenging (protecting) power than Tris, surprisingly, it led to higher rates of strand breakage. Based on the specific binding modes of arginine to DNA, we suggest that the side effects observed are due to the presence of arginine near to, but also inside, the DNA double helix. PMID:26994994

  4. Development of a High-Sensitivity Quantitation Method for Arginine Vasopressin by High-Performance Liquid Chromatography Tandem Mass Spectrometry, and Comparison with Quantitative Values by Radioimmunoassay.

    Science.gov (United States)

    Tsukazaki, Yasuko; Senda, Naoto; Kubo, Kinya; Yamada, Shigeru; Kugoh, Hiroyuki; Kazuki, Yasuhiro; Oshimura, Mitsuo

    2016-01-01

    Human plasma arginine vasopressin (AVP) levels serve as a clinically relevant marker of diabetes and related syndromes. We developed a highly sensitive method for measuring human plasma AVP using high-performance liquid chromatography tandem mass spectrometry. AVP was extracted from human plasma using a weak-cation solid-phase extraction plate, and separated on a wide-bore octadecyl reverse-phase column. AVP was quantified in ion-transition experiments utilizing a product ion (m/z 328.3) derived from its parent ion (m/z 542.8). The sensitivity was enhanced using 0.02% dichloromethane as a mobile-phase additive. The lower limit of quantitation was 0.200 pmol/L. The extraction recovery ranged from 70.2 ± 7.2 to 73.3 ± 6.2% (mean ± SD), and the matrix effect ranged from 1.1 - 1.9%. Quality-testing samples revealed interday/intraday accuracy and precision ranging over 0.9 - 3% and -0.3 - 2%, respectively, which included the endogenous baseline. Our results correlated well with radioimmunoassay results using 22 human volunteer plasma samples. PMID:26860558

  5. Activation of ENaC by AVP contributes to the urinary concentrating mechanism and dilution of plasma

    OpenAIRE

    Mironova, Elena; Chen, Yu; Pao, Alan C.; Roos, Karl P.; Kohan, Donald E.; Bugaj, Vladislav; Stockand, James D.

    2014-01-01

    Arginine vasopressin (AVP) activates the epithelial Na+ channel (ENaC). The physiological significance of this activation is unknown. The present study tested if activation of ENaC contributes to AVP-sensitive urinary concentration. Consumption of a 3% NaCl solution induced hypernatremia and plasma hypertonicity in mice. Plasma AVP concentration and urine osmolality increased in hypernatremic mice in an attempt to compensate for increases in plasma tonicity. ENaC activity was elevated in mice...

  6. Waves in unmagnetized plasma

    International Nuclear Information System (INIS)

    A review of linear and weakly non-linear theory of electron waves, ion waves and electromagnetic waves in plasmas is presented. The author restricts the discussion to an infinitely extended, homogeneous and isotropic plasma, not affected by external fields and described by Vlasov's and Maxwell's equations. (Auth.)

  7. Basis of Arginine Sensitivity of Microbial N-Acetyl-l-Glutamate Kinases: Mutagenesis and Protein Engineering Study with the Pseudomonas aeruginosa and Escherichia coli Enzymes▿

    OpenAIRE

    Fernández-Murga, M. Leonor; Rubio, Vicente

    2008-01-01

    N-Acetylglutamate kinase (NAGK) catalyzes the second step of arginine biosynthesis. In Pseudomonas aeruginosa, but not in Escherichia coli, this step is rate limiting and feedback and sigmoidally inhibited by arginine. Crystal structures revealed that arginine-insensitive E. coli NAGK (EcNAGK) is homodimeric, whereas arginine-inhibitable NAGKs, including P. aeruginosa NAGK (PaNAGK), are hexamers in which an extra N-terminal kinked helix (N-helix) interlinks three dimers. By introducing single...

  8. Stimulus-secretion coupling of arginine-induced insulin release: Comparison with histidine-induced insulin release

    International Nuclear Information System (INIS)

    L-Histidine, when tested at a 10-mM concentration, caused a rapid and sustained stimulation of insulin release from rat islets exposed to either D-glucose (7.0 or 8.3 mM) or L-leucine (10.0 mM). The stimulation of insulin release could not be ascribed to an increase in oxygen uptake, to the generation of histamine from L-histidine, or to its participation in a transglutaminase-catalyzed reaction. Like other cationic amino acids, however, L-histidine rapidly accumulated in islet cells, increased 86Rb outflow from prelabeled islets perifused in the presence or absence of extracellular Ca2+, and stimulated the entry of Ca2+ into islet cells. Yet, the amount of exogenous L-histidine present in the islet cells with a positively charged side chain was estimated to be below the threshold value required for stimulation of insulin release by fully ionized cationic amino acids, such as L-arginine. Hence, the present findings argue against the view that the insulinotropic action of cationic amino acids is solely attributable to the accumulation of these positively charged molecules inside the islet B cell with subsequent depolarization of the plasma membrane

  9. Protective effects of L-arginine on pulmonary oxidative stress and antioxidant defenses during exhaustive exercise in rats

    Institute of Scientific and Technical Information of China (English)

    Wan-teng LIN; Suh-ching YANG; Kung-tung CHEN; Chi-chang HUANG; Ning-yuean LEE

    2005-01-01

    Aim: To assess the effects of L-arginine (L-Arg) supplementation on pulmonary oxidative stress and antioxidant defenses in rats after exhaustive exercise. Methods:Rats were randomly divided into four groups: sedentary control (SC), sedentary control with L-Arg treatment (SC+Arg), exhaustive exercise with control diet (E)and exhaustive exercise with L-Arg treatment (E+Arg). Rats in groups SC+Arg and E+Arg received a 2% L-Arg diet. Rats in groups E and E+Arg underwent an exhaustive running test on a motorized treadmill. Pulmonary oxidative stress indices [xanthine oxidase (XO), myeloperoxidase (MPO), and malondialdehyde (MDA)] and antioxidant defense systems [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), and glutathione (GSH)] were investigated in this study. Results: L-Arg supplementation significantly reduced exercise-induced elevations of XO and MPO activities in lung. LArg reversed the exercise-induced increase in SOD and GR activities, but increased CAT and GPX activities. L-Arg administration also significantly increased the GSH levels in plasma. Conclusion: L-Arg supplementation can prevent elevations of XO and MPO activities in the lung and favorably influence pulmonary antioxidant defense systems after exhaustive exercise.

  10. Copeptin, a surrogate marker for arginine vasopressin secretion, is associated with higher glucose and insulin concentrations but not higher blood pressure in obese men

    DEFF Research Database (Denmark)

    Asferg, C L; Andersen, Ulrik Bjørn; Linneberg, A;

    2014-01-01

    was associated with higher serum insulin concentrations (r = 0.26, P = 0.0085) and insulin resistance as assessed by the homeostasis assessment model (r = 0.28, P = 0.0051). CONCLUSIONS: Plasma copeptin, a surrogate marker for arginine vasopressin secretion, is higher in obese men compared with normal...... distribution. METHODS: In 103 obese men (mean age ± standard deviation: 49.4 ± 10.2 years) and 27 normal weight control men (mean age: 51.5 ± 8.4 years), taking no medication, we measured 24-h ambulatory blood pressure, fasting blood concentrations of copeptin, lipids, glucose and insulin, and determined body...... weight men, and is associated with abnormalities in glucose and insulin metabolism, but not with higher blood pressure or an android fat distribution in obese men....

  11. Diurnal changes in polyamine content, arginine and ornithine decarboxylase, and diamine oxidase in tobacco leaves

    Czech Academy of Sciences Publication Activity Database

    Gemperlová, Lenka; Nováková, Marie; Vaňková, Radomíra; Eder, Josef; Cvikrová, Milena

    2006-01-01

    Roč. 57, č. 6 (2006), s. 1413-1421. ISSN 0022-0957 R&D Projects: GA ČR GA206/03/0369 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arginine decarboxylase * diamine oxidase * ornithine decarboxylase Subject RIV: ED - Physiology Impact factor: 3.630, year: 2006

  12. Impaired endothelial function after aneurysmal subarachnoid haemorrhage correlates with arginine:asymmetric dimethylarginine ratio

    DEFF Research Database (Denmark)

    Bergström, A; Staalsø, J M; Romner, B; Olsen, N V

    2014-01-01

    and arginine:ADMA ratio (r=0.43, P<0.005), but not with nitrite/nitrate, VMCA, or S-100B. CONCLUSIONS: Peripheral flow-mediated vasodilation is attenuated in the first days after SAH indicating acute systemic endothelial dysfunction. Impairment of endothelial function after SAH correlates with...

  13. Glutamine supplementation, citrulline production, and de novo arginine synthesis: Is there a relation?

    Science.gov (United States)

    We would like to comment on the recent publications by Buijs et al. The authors hypothesized that a parenteral supplement of glutamine stimulates citrulline formation and enhances de novo arginine synthesis. To test this hypothesis, they conducted an experiment with stable isotopes in patients under...

  14. Arginine-vasopressin stimulates the formation of phosphatidic acid in rat Leydig cells

    DEFF Research Database (Denmark)

    Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

    1987-01-01

    Arginine-vasopressin (AVP) stimulated the formation of labelled phosphatidic acid (PA) in [C]arachidonic acid-prelabelled rat Leydig cells. After addition of 10 M AVP [C]arachidonoylphosphatidic acid reached a maximum within 2 min. The increase was dose-dependent (10-10 M). No change in labelling...

  15. Levels of arginine-vasopressin in cerebrospinal fluid during passive avoidance behavior in rats

    NARCIS (Netherlands)

    Kloet, E.R. de; Laczi, F.; Gaffori, O.; Fekete, M.; Wied, D. de

    1984-01-01

    The concentration of immunoreactive arginine-vasopressin (IR-AVP) was measured in the cerebrospinal fluid (CSF) during acquisition and retention of passive avoidance behavior. IR-AVP level in CSF of male Wistar rats immediately after the learning trial was increased; the rate of which was related to

  16. Reduced preabsorptive insulin response in aged rats : differential effects of amphetamine and arginine-vasopressin

    NARCIS (Netherlands)

    Buwalda, B.; Strubbe, J.H.; Bohus, B.

    1991-01-01

    The experiments presented here have been designed to investigate whether the age-related attenuation of the vagal reactivity to emotional stressors and its modulation by amphetamine (Amph) or arginine-vasopressin (AVP) can be generalized for other physiological response patterns. We therefore studie

  17. Evidence for a metabolic shift of arginine metabolism in sickle cell disease

    NARCIS (Netherlands)

    Schnog, JJB; Jager, EH; van der Dijs, FPL; Duits, AJ; Moshage, H; Muskiet, FD; Muskiet, FAJ

    2004-01-01

    Over the last few years, a pivotal role has been ascribed to reduced nitric oxide (NO) availability as a contributing factor to the vaso-occlusive process of sickle cell disease. We investigated whether arginine metabolism in sickle cell patients is different from healthy controls. Blood samples wer

  18. Watermelon enhances arginine availability in an animal model of type-II diabetes

    Science.gov (United States)

    Watermelon fruit contain lycopene, a red pigment known for its ability to scavenge free hydroxyl radicals. L-Citrulline, an amino acid that acts as a vasodilator and is a precursor of L-arginine, is found in all cucurbits, but is most plentiful in watermelon. In a study with Zucker diabetic fatty ...

  19. Synergistic Protection of L-Arginine and Vitamin E On Lipid Peroxidation of Asthenospermic Patients

    Directory of Open Access Journals (Sweden)

    Sudha Srivastava

    2008-01-01

    Full Text Available Background: Lipid peroxidation is known to cause various impairments to sperm cells and mayplay a major role in the etiology of male infertility. Asthenospermia is the main factor of maleinfertility and has significantly higher level of peroxidation than in normozoospermic males.Materials and Methods: Using thiobarbituric acid (TBA assay procedure, we have determinedthe level of lipid peroxidation as indicated by malondialdehyde (MDA in the spermatozoa obtainedfrom asthenospermic male semen.Results: An inverse correlation of MDA concentration with sperm motility is observed. Treatmentof cells with L-arginine and vitamin E significantly decreases the MDA concentration and improvesthe sperm motility as compared to that in case of control samples. A combination of L-arginine andvitamin E shows synergistic effect on sperm motility and prevention of lipid peroxidation.Conclusion: L-arginine and vitamin E protect the cells against the loss of sperm motility by lipidperoxidation. Therefore, supplementation of both L-arginine and vitamin E may improve spermmotility and increase the possibility of fertilization in asthenospermic subjects.

  20. Guanidinium Cations Pair with Positively Charged Arginine Side Chains in Water

    Czech Academy of Sciences Publication Activity Database

    Kubíčková, A.; Křížek, T.; Coufal, P.; Wernersson, Erik; Heyda, Jan; Jungwirth, Pavel

    2011-01-01

    Roč. 2, č. 12 (2011), s. 1387-1389. ISSN 1948-7185 R&D Projects: GA ČR GA203/08/0114; GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : guanidinium * cations * arginine * electrophoresis * water Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.213, year: 2011

  1. Ubiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane.

    LENUS (Irish Health Repository)

    Knodler, Leigh A

    2009-11-01

    The Salmonella type III effector, SopB, is an inositol polyphosphate phosphatase that modulates host cell phospholipids at the plasma membrane and the nascent Salmonella-containing vacuole (SCV). Translocated SopB persists for many hours after infection and is ubiquitinated but the significance of this covalent modification has not been investigated. Here we identify by mass spectrometry six lysine residues of SopB that are mono-ubiquitinated. Substitution of these six lysine residues with arginine, SopB-K(6)R, almost completely eliminated SopB ubiquitination. We found that ubiquitination does not affect SopB stability or membrane association, or SopB-dependent events in SCV biogenesis. However, two spatially and temporally distinct events are dependent on ubiquitination, downregulation of SopB activity at the plasma membrane and prolonged retention of SopB on the SCV. Activation of the mammalian pro-survival kinase Akt\\/PKB, a downstream target of SopB, was intensified and prolonged after infection with the SopB-K(6)R mutant. At later times, fewer SCV were decorated with SopB-K(6)R compared with SopB. Instead SopB-K(6)R was present as discrete vesicles spread diffusely throughout the cell. Altogether, our data show that ubiquitination of SopB is not related to its intracellular stability but rather regulates its enzymatic activity at the plasma membrane and intracellular localization.

  2. Effect of arginase inhibition on pulmonary L-arginine metabolism in murine Pseudomonas pneumonia.

    Directory of Open Access Journals (Sweden)

    Anne Mehl

    Full Text Available RATIONALE: Infection of the lung with Pseudomonas aeruginosa results in upregulation of nitric oxide synthases (NOS and arginase expression, and both enzymes compete for L-arginine as substrate. Nitric oxide (NO production may be regulated by arginase as it controls L-arginine availability for NOS. We here studied the effect of systemic arginase inhibition on pulmonary L-arginine metabolism in Pseudomonas pneumonia in the mouse. METHODS: Mice (C57BL/6, 8-10 weeks old, female underwent direct tracheal instillation of Pseudomonas (PAO-1-coated agar beads and were treated by repeated intra-peritoneal injections of the arginase inhibitor 2(S-amino-6-boronohexanoic acid (ABH or PBS until lungs were harvested on day 3 of the infection. L-arginine metabolites were quantified using liquid chromatography-tandem mass spectrometry, NO metabolites nitrate and nitrite by Griess reagent and cytokines by ELISA. RESULTS: NO metabolite concentrations (48.5±2.9 vs. 10.9±2.3 µM, p<0.0001, as well as L-ornithine (29.6±1.7 vs 2.3±0.4 µM, p<0.0001, the product of arginase activity, were increased in Pseudomonas infected lungs compared to naïve controls. Concentrations of the NOS inhibitor asymmetric dimethylarginine (ADMA were also increased (0.44±0.02 vs. 0.16±0.01 µM, p<0.0001. Arginase inhibition in the infected animals resulted in a significant decrease in L-ornithine (14.6±1.6 µM, p<0.0001 but increase in L-arginine concentration (p<0.001, L-arginine/ADMA ratio (p<0.001, L-arginine availability for NOS (p<0.001, and NO metabolite concentrations (67.3±5.7 µM, p<0.05. Arginase inhibitor treatment also resulted in an increase in NO metabolite levels in animals following intratracheal injection of LPS (p = 0.015. Arginase inhibition was not associated with an increase in inflammatory markers (IFN-γ, IL-1β, IL-6, MIP-2, KC or TNF-α in lung. Concentrations of the L-ornithine-dependent polyamines putrescine, spermidine and spermine were increased

  3. Role of N-Nitro-L-Arginine-Methylester as anti-oxidant in transient cerebral ischemia and reperfusion in rats

    Directory of Open Access Journals (Sweden)

    Awooda Hiba A

    2013-01-01

    Full Text Available Abstract Background Previous reports assessing the neuroprotective role of nonselective Nitric Oxide synthase (NOS inhibitor N-nitro-L-arginine-methylester (L-NAME following cerebral ischemia/reperfusion are contradictory. The aim of this work was to examine the potential benefits of L-NAME on rats subjected to transient focal cerebral ischemia/reperfusion. Methods The study involved 30 adult male Wistar rats divided into three groups 10 rats in each: First group was sham-operated and served as a control, a ischemia/reperfusion (I/R group of rats infused with 0.9% normal saline intraperitoneally 15 minutes prior to 30 minutes of left common carotid artery (CCA occlusion and a test group infused with L-NAME intraperitoneally 15 minutes prior to ischemia. Neurobehavioral assessments were evaluated and quantitative assessment of malondialdehyde (MDA, Nitric oxide (NO metabolites and total antioxidant capacity (TAC in both serum and the affected cerebral hemisphere were achieved. Results Rats’ neurological deficit and TAC were significantly decreased while NO and MDA were significantly increased in the I/R compared with the control group (P Conclusions L-NAME pretreatment for rats undergoing cerebral ischemia/reperfusion significantly improves neurological deficit while reducing oxidative stress biomarkers in the affected cerebral hemisphere.

  4. Plasma theory

    International Nuclear Information System (INIS)

    A series of lectures on plasma theory with the main headings: introduction; charged particles moving in em fields; the liquid model; transport phenomena in the plasma; wave propagation in plasmas; plasma instabilities. 57 figs. (qui)

  5. Vasopressin in plasma and CSF of patients with subarachnoid haemorrhage.

    OpenAIRE

    Mather, H. M.; Ang, V; Jenkins, J. S.

    1981-01-01

    Arginine vasopressin was measured in the blood and cerebrospinal fluid (CSF) of 42 patients with subarachnoid haemorrhage. Increased concentrations of vasopressin were present in 10 patients, of whom eight had bled from an anterior communicating artery aneurysm. In three patients high blood vasopressin values were associated with gross hyponatraemia. Five patients were found to have increased CSF vasopressin concentrations in the presence of normal plasma values and in all of these the level ...

  6. The effect of L-Arginine on the brain tissue of stressed rats

    Directory of Open Access Journals (Sweden)

    Batoul Ebadi

    2010-01-01

    Full Text Available   Abstract  Introduction: This study was conducted to determine the possible beneficial results of L-arginine on prefrontal cortex of rats which impressed by immobilization stress to define the synchronous impression of stress and nitric oxide (NO on evolution of prefrontal cortex of rats after birth. Methods: Forty-eight one month, male Wistar rats were divided into two groups: stressed and non-stressed. L-Arginine (200 mg/kg as a NO synthase (NOS inducer and L-NAME (2O mg/kg were injected intraperitonealy (IP and 7- nitroindazde (25 mg/kg as non-specific was injected subcutaneously (S.C. for 4 weeks. The kind of stress was immobilization for 4 weeks, every other day. The brain was removed after this period and each brain divided into two parts in a coronal section manner. Anterior part used for histological studies with H&E staining and posterior part used for measurement of NO production using spectrophotometer at 540 nm wavelengh. Results: Statistical analysis of microscopic and light microscopic finding showed that thickness of prefrontal cortex and NO production were significantly decreased in stressed rats and especially in groups which received 7- nitroindazole and L-NAME and L-arginine could reverse these results. Discussion: According to this research, we could say that L-arginine decreases the cortical damages in stressed rats and 7-nitroindazole and L-NAME increase this damage in non-stressed group. Although in non stressed groups, L-arginine, L-NAME and 7- nitroindazole were all non-protective and damaging.

  7. Supplemental arginine above the requirement during suckling causes obesity and insulin resistance in rats.

    Science.gov (United States)

    Otani, Lila; Mori, Tomomi; Koyama, Ayaka; Takahashi, Shin-Ichiro; Kato, Hisanori

    2016-06-01

    Nutrition in early life is important in determining susceptibility to adult obesity, and arginine may promote growth acceleration in infants. We hypothesized that maternal arginine supplementation may promote growth in their pups and contribute to obesity and alteration of the metabolic system in later life. Dams and pups of Wistar rats were given a normal diet (15% protein) as a control (CN) or a normal diet with 2% arginine (ARG). Altered profiles of free amino acids in breast milk were observed in that the concentrations of threonine and glycine were lower in the ARG dams compared with the CN dams. The offspring of the CN and ARG dams were further subdivided into normal-diet (CN-CN and ARG-CN) groups and a high fat-diet groups (CN-HF and ARG-HF). In response to the high fat-diet feeding, the visceral fat deposits were significantly increased in the ARG-HF group (although not compared with the CN-HF group); no difference was observed between the CN-CN and ARG-CN groups. The blood glucose and insulin levels after glucose loading were significantly higher in the ARG-HF group compared with the CN-HF group. The results suggest that the offspring of dams supplemented with arginine during lactation acquired increased susceptibility to a high-fat diet, resulting in visceral obesity and insulin resistance. The lower supply of threonine and glycine to pups may be one of the contributing causes to the programming of lifelong obesity risk in offspring. Our findings also indicated that maternal arginine supplementation during suckling causes obesity and insulin resistance in rats. PMID:27188903

  8. Glutamine, glutamate, and arginine-based acid resistance in Lactobacillus reuteri.

    Science.gov (United States)

    Teixeira, Januana S; Seeras, Arisha; Sanchez-Maldonado, Alma Fernanda; Zhang, Chonggang; Su, Marcia Shu-Wei; Gänzle, Michael G

    2014-09-01

    This study aimed to determine whether glutamine deamidation improves acid resistance of Lactobacillus reuteri, and to assess whether arginine, glutamine, and glutamate-mediated acid resistance are redundant or complementary mechanisms of acid resistance. Three putative glutaminase genes, gls1, gls2, and gls3, were identified in L. reuteri 100-23. All three genes were expressed during growth in mMRS and wheat sourdough. L. reuteri consistently over-expressed gls3 and the glutamate decarboxylase gadB. L. reuteri 100-23ΔgadB over-expressed gls3 and the arginine deiminase gene adi. Analysis of the survival of L. reuteri in acidic conditions revealed that arginine conversion is effective at pH of 3.5 while glutamine or glutamate conversion were effective at pH of 2.5. Arginine conversion increased the pHin but not ΔΨ; glutamate decarboxylation had only a minor effect on the pHin but increased the ΔΨ. This study demonstrates that glutamine deamidation increases the acid resistance of L. reuteri independent of glutamate decarboxylase activity. Arginine and glutamine/glutamate conversions confer resistance to lactate at pH of 3.5 and phosphate at pH of 2.5, respectively. Knowledge of L. reuteri's acid resistance improves the understanding of the adaptation of L. reuteri to intestinal ecosystems, and facilitates the selection of probiotic and starter cultures. PMID:24929734

  9. Sex differences in the effects of MDMA (ecstasy) on plasma copeptin in healthy subjects

    OpenAIRE

    Simmler, L. D.; Hysek, C M; Liechti, M. E.

    2011-01-01

    BACKGROUND:3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) misuse is associated with hyponatremia particularly in women. Hyponatremia is possibly due to inappropriate secretion of plasma arginine vasopressin (AVP). OBJECTIVE: To assess whether MDMA increases plasma AVP and copeptin in healthy male and female subjects and whether effects depend on MDMA-induced release of serotonin and norepinephrine. Copeptin, the C-terminal part of the AVP precursor preprovasopressin, is cosecreted with AVP...

  10. Neuropsychological profile and clinical effects of arginine treatment in children with creatine transport deficiency

    Directory of Open Access Journals (Sweden)

    Chilosi Annamaria

    2012-06-01

    Full Text Available Abstract Background SLC6A8, an X-linked gene, encodes the creatine transporter (CRTR and its mutations lead to cerebral creatine (Cr deficiency which results in mental retardation, speech and language delay, autistic-like behaviour and epilepsy (CRTR-D, OMIM 300352. CRTR-D represents the most frequent Cr metabolism disorder but, differently from Cr synthesis defects, that are partially reversible by oral Cr supplementation, does not respond to Cr treatment even if precociously administrated. The precursors of Cr are the non-essential amino acids Glycine (Gly and Arginine (Arg, which have their own transporters at the brain–blood barrier level and, therefore, their supplementation appears an attractive and feasible therapeutic option aimed at stimulating Cr endogenous synthesis and, in this way, at overcoming the block of Cr transport within the brain. However, until now the effects of Arg and/or Gly supplementation on Cr brain levels and behaviour have been controversial. Methods In this study five Italian male patients affected by CRTR-D were supplemented with oral L-Arg at a dosage of 300 mg/kg/day divided into 3 doses, for 24–36 months. Biochemical and plasmatic amino acids examinations and thyroid hormone dosages were periodically performed. Moreover, Proton and Phosphorus Magnetic Resonance Spectroscopy (MRS was monitored during follow-up in concurrence with neuropsychological evaluations. Results During L-Arg treatment a clinical improvement in motor skills and to a lesser extent in communication and attention was observed. In addition, all patients had a reduction in the number and frequency of epileptic seizures. Daily living skills appeared also to be positively influenced by L-Arg treatment. Moreover, Total Cr and especially PhosphoCr, evaluated by proton and phosphorus spectroscopy, showed a mild increase, although well below the normal range. Conclusion This study provides information to support the effectiveness of L

  11. Inversion of allosteric effect of arginine on N-acetylglutamate synthase, a molecular marker for evolution of tetrapods

    Directory of Open Access Journals (Sweden)

    Cabrera-Luque Juan

    2008-09-01

    Full Text Available Abstract Background The efficient conversion of ammonia, a potent neurotoxin, into non-toxic metabolites was an essential adaptation that allowed animals to move from the aquatic to terrestrial biosphere. The urea cycle converts ammonia into urea in mammals, amphibians, turtles, snails, worms and many aquatic animals and requires N-acetylglutamate (NAG, an essential allosteric activator of carbamylphosphate synthetase I (CPSI in mammals and amphibians, and carbamylphosphate synthetase III (CPSIII in fish and invertebrates. NAG-dependent CPSI and CPSIII catalyze the formation of carbamylphosphate in the first and rate limiting step of ureagenesis. NAG is produced enzymatically by N-acetylglutamate synthase (NAGS, which is also found in bacteria and plants as the first enzyme of arginine biosynthesis. Arginine is an allosteric inhibitor of microbial and plant NAGS, and allosteric activator of mammalian NAGS. Results Information from mutagenesis studies of E. coli and P. aeruginosa NAGS was combined with structural information from the related bacterial N-acetylglutamate kinases to identify four residues in mammalian NAGS that interact with arginine. Substitutions of these four residues were engineered in mouse NAGS and into the vertebrate-like N-acetylglutamate synthase-kinase (NAGS-K of Xanthomonas campestris, which is inhibited by arginine. All mutations resulted in arginine losing the ability to activate mouse NAGS, and inhibit X. campestris NAGS-K. To examine at what point in evolution inversion of arginine effect on NAGS occur, we cloned NAGS from fish and frogs and examined the arginine response of their corresponding proteins. Fish NAGS were partially inhibited by arginine and frog NAGS were activated by arginine. Conclusion Difference in arginine effect on bacterial and mammalian NAGS most likely stems from the difference in the type of conformational change triggered by arginine binding to these proteins. The change from arginine

  12. The Hydrophobic Region of the DmsA Twin-Arginine Leader Peptide Determines Specificity with Chaperone DmsD

    OpenAIRE

    Winstone, Tara M. L.; Tran, Vy A.; Turner, Raymond J.

    2013-01-01

    The system specific chaperone DmsD plays a role in the maturation of the catalytic subunit of dimethyl sulfoxide (DMSO) reductase, DmsA. Pre-DmsA contains a 45-amino acid twin-arginine leader peptide that is important for targeting and translocation of folded and cofactor-loaded DmsA by the twin-arginine translocase. DmsD has previously been shown to interact with the complete twin-arginine leader peptide of DmsA. In this study, isothermal titration calorimetry was used to investigate the the...

  13. Arginine-based cationic liposomes for efficient in vitro plasmid DNA delivery with low cytotoxicity

    Directory of Open Access Journals (Sweden)

    Sarker SR

    2013-04-01

    Full Text Available Satya Ranjan Sarker, Yumiko Aoshima, Ryosuke Hokama, Takafumi Inoue, Keitaro Sou, Shinji Takeoka Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University (TWIns, Tokyo, Japan Background: Currently available gene delivery vehicles have many limitations such as low gene delivery efficiency and high cytotoxicity. To overcome these drawbacks, we designed and synthesized two cationic lipids comprised of n-tetradecyl alcohol as the hydrophobic moiety, 3-hydrocarbon chain as the spacer, and different counterions (eg, hydrogen chloride [HCl] salt or trifluoroacetic acid [TFA] salt in the arginine head group. Methods: Cationic lipids were hydrated in 4-(2-hydroxyethyl-1-piperazineethanesulfonic acid (HEPES buffer to prepare cationic liposomes and characterized in terms of their size, zeta potential, phase transition temperature, and morphology. Lipoplexes were then prepared and characterized in terms of their size and zeta potential in the absence or presence of serum. The morphology of the lipoplexes was determined using transmission electron microscopy and atomic force microscopy. The gene delivery efficiency was evaluated in neuronal cells and HeLa cells and compared with that of lysine-based cationic assemblies and Lipofectamine™ 2000. The cytotoxicity level of the cationic lipids was investigated and compared with that of Lipofectamine™ 2000. Results: We synthesized arginine-based cationic lipids having different counterions (ie, HCl-salt or TFA-salt that formed cationic liposomes of around 100 nm in size. In the absence of serum, lipoplexes prepared from the arginine-based cationic liposomes and plasmid (p DNA formed large aggregates and attained a positive zeta potential. However, in the presence of serum, the lipoplexes were smaller in size and negative in zeta potential. The morphology of the lipoplexes was vesicular. Arginine-based cationic liposomes with HCl-salt showed the

  14. Insight on an arginine synthesis metabolon from the tetrameric structure of yeast acetylglutamate kinase.

    Directory of Open Access Journals (Sweden)

    Sergio de Cima

    Full Text Available N-acetyl-L-glutamate kinase (NAGK catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS, which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yNAGK has, in addition to the amino acid kinase (AAK domain found in other NAGKs, a ~150-residue C-terminal domain of unclear significance belonging to the DUF619 domain family. We deleted this domain, proving that it stabilizes yNAGK, slows catalysis and modulates feed-back inhibition by arginine. We determined the crystal structures of both the DUF619 domain-lacking yNAGK, ligand-free as well as complexed with acetylglutamate or acetylglutamate and arginine, and of complete mature yNAGK. While all other known arginine-inhibitable NAGKs are doughnut-like hexameric trimers of dimers of AAK domains, yNAGK has as central structure a flat tetramer formed by two dimers of AAK domains. These dimers differ from canonical AAK dimers in the -110° rotation of one subunit with respect to the other. In the hexameric enzymes, an N-terminal extension, found in all arginine-inhibitable NAGKs, forms a protruding helix that interlaces the dimers. In yNAGK, however, it conforms a two-helix platform that mediates interdimeric interactions. Arginine appears to freeze an open inactive AAK domain conformation. In the complete yNAGK structure, two pairs of DUF619 domains flank the AAK domain tetramer, providing a mechanism for the DUF619 domain modulatory functions. The DUF619 domain exhibits the histone acetyltransferase fold, resembling the catalytic domain of bacterial NAGS. However, the putative acetyl CoA site is blocked, explaining the lack of NAGS activity of yNAGK. We conclude that the tetrameric architecture is an adaptation to metabolon formation and propose an organization for this metabolon, suggesting that yNAGK may be a good model also for yeast and human NAGSs.

  15. Insight on an arginine synthesis metabolon from the tetrameric structure of yeast acetylglutamate kinase.

    Science.gov (United States)

    de Cima, Sergio; Gil-Ortiz, Fernando; Crabeel, Marjolaine; Fita, Ignacio; Rubio, Vicente

    2012-01-01

    N-acetyl-L-glutamate kinase (NAGK) catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS), which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yNAGK) has, in addition to the amino acid kinase (AAK) domain found in other NAGKs, a ~150-residue C-terminal domain of unclear significance belonging to the DUF619 domain family. We deleted this domain, proving that it stabilizes yNAGK, slows catalysis and modulates feed-back inhibition by arginine. We determined the crystal structures of both the DUF619 domain-lacking yNAGK, ligand-free as well as complexed with acetylglutamate or acetylglutamate and arginine, and of complete mature yNAGK. While all other known arginine-inhibitable NAGKs are doughnut-like hexameric trimers of dimers of AAK domains, yNAGK has as central structure a flat tetramer formed by two dimers of AAK domains. These dimers differ from canonical AAK dimers in the -110° rotation of one subunit with respect to the other. In the hexameric enzymes, an N-terminal extension, found in all arginine-inhibitable NAGKs, forms a protruding helix that interlaces the dimers. In yNAGK, however, it conforms a two-helix platform that mediates interdimeric interactions. Arginine appears to freeze an open inactive AAK domain conformation. In the complete yNAGK structure, two pairs of DUF619 domains flank the AAK domain tetramer, providing a mechanism for the DUF619 domain modulatory functions. The DUF619 domain exhibits the histone acetyltransferase fold, resembling the catalytic domain of bacterial NAGS. However, the putative acetyl CoA site is blocked, explaining the lack of NAGS activity of yNAGK. We conclude that the tetrameric architecture is an adaptation to metabolon formation and propose an organization for this metabolon, suggesting that yNAGK may be a good model also for yeast and human NAGSs. PMID:22529931

  16. Dysregulated expression of arginine metabolic enzymes in human intestinal tissues of necrotizing enterocolitis and response of CaCO2 cells to bacterial components.

    Science.gov (United States)

    Leung, Kam Tong; Chan, Kathy Yuen Yee; Ma, Terence Ping Yuen; Yu, Jasmine Wai Sum; Tong, Joanna Hung Man; Tam, Yuk Him; Cheung, Hon Ming; To, Ka Fai; Lam, Hugh Simon; Lee, Kim Hung; Li, Karen; Ng, Pak Cheung

    2016-03-01

    The small intestine is the exclusive site of arginine synthesis in neonates. Low levels of circulating arginine have been associated with the occurrence of necrotizing enterocolitis (NEC) but the mechanism of arginine dysregulation has not been fully elucidated. We aimed to investigate (i) expressional changes of arginine synthesizing and catabolic enzymes in human intestinal tissues of NEC, spontaneous intestinal perforation (SIP) and noninflammatory surgical conditions (Surg-CTL) and to investigate the (ii) mechanisms of arginine dysregulation and enterocyte proliferation upon stimulation by bacterial components, arginine depletion, ARG1 overexpression and nitric oxide (NO) supplementation. Our results showed that expressions of arginine synthesizing enzymes ALDH18A1, ASL, ASS1, CPS1, GLS, OAT and PRODH were significantly decreased in NEC compared with Surg-CTL or SIP tissues. Catabolic enzyme ARG1 was increased (>100-fold) in NEC tissues and histologically demonstrated to be expressed by infiltrating neutrophils. No change in arginine metabolic enzymes was observed between SIP and Surg-CTL tissues. In CaCO2 cells, arginine metabolic enzymes were differentially dysregulated by lipopolysaccharide or lipoteichoic acid. Depletion of arginine reduced cell proliferation and this phenomenon could be partially rescued by NO. Overexpression of ARG1 also reduced enterocyte proliferation. We provided the first expressional profile of arginine metabolic enzymes at the tissue level of NEC. Our findings suggested that arginine homeostasis was severely disturbed and could be triggered by inflammatory responses of enterocytes and infiltrating neutrophils as well as bacterial components. Such reactions could reduce arginine and NO, resulting in mucosal damage. The benefit of arginine supplementation for NEC prophylaxis merits further clinical evaluation. PMID:26895666

  17. Environmental factors affecting pregnancy: endocrine disrupters, nutrients and metabolic pathways.

    Science.gov (United States)

    Bazer, Fuller W; Wu, Guoyao; Johnson, Gregory A; Wang, Xiaoqiu

    2014-12-01

    Uterine adenogenesis, a unique post-natal event in mammals, is vulnerable to endocrine disruption by estrogens and progestins resulting in infertility or reduced prolificacy. The absence of uterine glands results in insufficient transport of nutrients into the uterine lumen to support conceptus development. Arginine, a component of histotroph, is substrate for production of nitric oxide, polyamines and agmatine and, with secreted phosphoprotein 1, it affects cytoskeletal organization of trophectoderm. Arginine is critical for development of the conceptus, pregnancy recognition signaling, implantation and placentation. Conceptuses of ungulates and cetaceans convert glucose to fructose which is metabolized via multiple pathways to support growth and development. However, high fructose corn syrup in soft drinks and foods may increase risks for metabolic disorders and increase insulin resistance in adults. Understanding endocrine disrupters and dietary substances, and novel pathways for nutrient metabolism during pregnancy can improve survival and growth, and prevent chronic metabolic diseases in offspring. PMID:25224489

  18. Kidney Function and Plasma Copeptin Levels in Healthy Kidney Donors and Autosomal Dominant Polycystic Kidney Disease Patients

    NARCIS (Netherlands)

    Zittema, Debbie; van den Berg, Else; Meijer, Esther; Boertien, Wendy E.; Muller Kobold, Anneke C.; Franssen, Casper F. M.; de Jong, Paul E.; Bakker, Stephan J. L.; Navis, Gerjan; Gansevoort, Ron T.

    2014-01-01

    Background and objectives Plasma copeptin, a marker of arginine vasopressin, is elevated in patients with autosomal dominant polycystic kidney disease and predicts disease progression. It is unknown whether elevated copeptin levels result from decreased kidney clearance or as compensation for impair

  19. Nanoscale characterization of effect of L-arginine on Streptococcus mutans biofilm adhesion by atomic force microscopy.

    Science.gov (United States)

    Sharma, Shivani; Lavender, Stacey; Woo, JungReem; Guo, Lihong; Shi, Wenyuan; Kilpatrick-Liverman, LaTonya; Gimzewski, James K

    2014-07-01

    A major aetiological factor of dental caries is the pathology of the dental plaque biofilms. The amino acid L-arginine (Arg) is found naturally in saliva as a free molecule or as a part of salivary peptides and proteins. Plaque bacteria metabolize Arg to produce alkali and neutralize glycolytic acids, promoting a less cariogenous oral microbiome. Here, we explored an alternative and complementary mechanism of action of Arg using atomic force microscopy. The nanomechanical properties of Streptococcus mutans biofilm extracellular matrix were characterized under physiological buffer conditions. We report the effect of Arg on the adhesive behaviour and structural properties of extracellular polysaccharides in S. mutans biofilms. High-resolution imaging of biofilm surfaces can reveal additional structural information on bacterial cells embedded within the surrounding extracellular matrix. A dense extracellular matrix was observed in biofilms without Arg compared to those grown in the presence of Arg. S. mutans biofilms grown in the presence of Arg could influence the production and/or composition of extracellular membrane glucans and thereby affect their adhesion properties. Our results suggest that the presence of Arg in the oral cavity could influence the adhesion properties of S. mutans to the tooth surface. PMID:24763427

  20. Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function

    KAUST Repository

    Rydberg, Hanna A.

    2012-10-01

    Cell-penetrating peptides and antimicrobial peptides are two classes of positively charged membrane active peptides with several properties in common. The challenge is to combine knowledge about the membrane interaction mechanisms and structural properties of the two classes to design peptides with membrane-specific actions, useful either as transporters of cargo or as antibacterial substances. Membrane active peptides are commonly rich in arginine and tryptophan. We have previously designed a series of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations assay (MIC), circular dichroism (CD) and linear dichroism (LD). The results show that the arg/trp peptides inhibit the growth of the two gram positive strains Staphylococcus aureus and Staphylococcus pyogenes, with some individual variations depending on the position of the tryptophans. No inhibition of the gram negative strains Proteus mirabilis or Pseudomonas aeruginosa was noticed. CD indicated that when bound to lipid vesicles one of the peptides forms an α-helical like structure, whereas the other five exhibited rather random coiled structures. LD indicated that all six peptides were somehow aligned parallel with the membrane surface. Our results do not reveal any obvious connection between membrane interaction and antimicrobial effect for the studied peptides. By contrast cell-penetrating properties can be coupled to both the secondary structure and the degree of order of the peptides. © 2012 Elsevier Inc.

  1. Detrimental effects of Bartonella henselae are counteracted by L-arginine and nitric oxide in human endothelial progenitor cells.

    Science.gov (United States)

    Salvatore, Paola; Casamassimi, Amelia; Sommese, Linda; Fiorito, Carmela; Ciccodicola, Alfredo; Rossiello, Raffaele; Avallone, Bice; Grimaldi, Vincenzo; Costa, Valerio; Rienzo, Monica; Colicchio, Roberta; Williams-Ignarro, Sharon; Pagliarulo, Caterina; Prudente, Maria Evelina; Abbondanza, Ciro; Lamberti, Florentia; Baroni, Adone; Buommino, Elisabetta; Farzati, Bartolomeo; Tufano, Maria Antonietta; Ignarro, Louis Joseph; Napoli, Claudio

    2008-07-01

    The recruitment of circulating endothelial progenitor cells (EPCs) might have a beneficial effect on the clinical course of several diseases. Endothelial damage and detachment of endothelial cells are known to occur in infection, tissue ischemia, and sepsis. These detrimental effects in EPCs are unknown. Here we elucidated whether human EPCs internalize Bartonella henselae constituting a circulating niche of the pathogen. B. henselae invades EPCs as shown by gentamicin protection assays and transmission electron microscopy (TEM). Dil-Ac-LDL/lectin double immunostaining and fluorescence-activated cell sorting (FACS) analysis of EPCs revealed EPC bioactivity after infection with B. henselae. Nitric oxide (NO) and its precursor l-arginine (l-arg) exert a plethora of beneficial effects on vascular function and modulation of immune response. Therefore, we tested also the hypothesis that l-arg (1-30 mM) would affect the infection of B. henselae or tumor necrosis factor (TNF) in EPCs. Our data provide evidence that l-arg counteracts detrimental effects induced by TNF or Bartonella infections via NO (confirmed by DETA-NO and L-NMMA experiments) and by modulation of p38 kinase phosphorylation. Microarray analysis indicated several genes involved in immune response were differentially expressed in Bartonella-infected EPCs, whereas these genes returned in steady state when cells were exposed to sustained doses of l-arg. This mechanism may have broad therapeutic applications in tissue ischemia, angiogenesis, immune response, and sepsis. PMID:18595894

  2. High-performance liquid chromatography method with radiochemical detection for measurement of nitric oxide synthase, arginase, and arginine decarboxylase activities

    DEFF Research Database (Denmark)

    Volke, A; Wegener, Gregers; Vasar, E;

    2006-01-01

    Nitric oxide has been shown to be involved in numerous biological processes, and many studies have aimed to measure nitric oxide synthase (NOS) activity. Recently, it has been demonstrated that arginase and arginine decarboxylase (ADC), two enzymes that also employ arginine as a substrate, may...... simple and fast HPLC method with radiochemical detection to separate radiolabeled L-arginine, L-citrulline, L-ornithine, and agmatine. 3H-labeled L-arginine, L-citrulline, agmatine, and 14C-labeled L-citrulline were used as standards. These compounds were separated in the normal phase column (Allure...... Acidix 250 x 4.6 mm i.d.) under isocratic conditions in less than 20 min with good sensitivity. Using the current method, we have shown the formation of L-citrulline and L-ornithine in vitro using brain tissue homogenate of rats and that of agmatine by Escherichia coli ADC. Udgivelsesdato: null-null...

  3. Effects of a food supplement rich in arginine in patients with smear positive pulmonary tuberculosis--a randomised trial

    DEFF Research Database (Denmark)

    Schön, T; Idh, J; Westman, A;

    2011-01-01

    In tuberculosis (TB), the production of nitric oxide (NO) is confirmed but its importance in host defense is debated. Our aim was to investigate whether a food supplement rich in arginine could enhance clinical improvement in TB patients by increased NO production. Smear positive TB patients from...... Gondar, Ethiopia (n = 180) were randomized to a food supplementation rich in arginine (peanuts, equivalent to 1 g of arginine/day) or with a low arginine content (wheat crackers, locally called daboqolo) during four weeks. The primary outcome was cure rate according to the WHO classification and...... secondary outcomes. In the subgroup analysis according to HIV status, peanut supplemented HIV+/TB patients showed increased cure rate (83.8% (31/37) vs 53.1% (17/32), p <0.01). A low baseline eNO (...

  4. One-Pot Green Synthesis and Bioapplication of l-Arginine-Capped Superparamagnetic Fe3O4 Nanoparticles

    Science.gov (United States)

    Lai, Yongchao; Yin, Weiwei; Liu, Jinting; Xi, Rimo; Zhan, Jinhua

    2010-02-01

    Water-soluble l-arginine-capped Fe3O4 nanoparticles were synthesized using a one-pot and green method. Nontoxic, renewable and inexpensive reagents including FeCl3, l-arginine, glycerol and water were chosen as raw materials. Fe3O4 nanoparticles show different dispersive states in acidic and alkaline solutions for the two distinct forms of surface binding l-arginine. Powder X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the structure of Fe3O4 nanocrystals. The products behave like superparamagnetism at room temperature with saturation magnetization of 49.9 emu g-1 and negligible remanence or coercivity. In the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride, the anti-chloramphenicol monoclonal antibodies were connected to the l-arginine-capped magnetite nanoparticles. The as-prepared conjugates could be used in immunomagnetic assay.

  5. Effects of Postoperative Enteral Immune-enhancing Diet on Plasma Endotoxin Level, Plasma Endotoxin Inactivation Capacity and Clinical Outcome

    Institute of Scientific and Technical Information of China (English)

    YAO Guoxiang; XUE Xinbo; LU Xingpei; WANG Jianming; QIAN Jiaqin

    2005-01-01

    This study examined the postoperative plasma endotoxin level, plasma endotoxin inactivation capacity and clinical outcome after administration of an enteral diet supplemented with glutamine, arginine and ω-3-fatty acid in patients undergoing gastrointestinal operations on an prospective, randomized and double-blind design. 40 patients undergoing gastrointestinal operations were randomized into two groups, with each having 20 patients. One group received standard enteral nutrition and the other was fed the formulation supplemented with glutamine, arginine and ω-3-fatty acid. The two groups were isonitrogenous. The infusion was started from day 1 after surgery and continued for 7 days. Blood samples were collected on the morning of day 1 before operation and on the morning of 1, 4 and 7 day(s) after operation and analyzed for plasma endotoxin level and endotoxin inactivation capacity (EIC). Our study found no differences between the two groups on plasma endotoxin level. After surgery a rapid reduction in plasma endotoxin inactivation capacity was observed in both groups, a significant recovery of the plasma endotoxin inactivation capacity was observed on morning of day 4 after surgery in the study group (0.12±0.02 EU/mL and 0. 078±0.022 EU/mL respectively, P<0.01). Shortened hospital stay was observed in the experimental group (11.7±2.0 days in the control group and 10.6±1.2 days in the experimental group respectively, P=0.03). It is concluded that perioperative parenteral nutrition supplemented with glutamine, arginine and ω-3-fatty acid ameliorated postoperative immunodepression but without direct effect on endotoxemia.

  6. Oral L-Arginine Stimulates GLP-1 Secretion to Improve Glucose Tolerance in Male Mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Smajilovic, Sanela; Smith, Eric P;

    2013-01-01

    Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet-induced o......Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet......-induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid l-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral l-arginine acts as a GLP-1 secretagogue in...

  7. Twin-arginine-dependent translocation of SufI in the absence of cytosolic helper proteins.

    Science.gov (United States)

    Holzapfel, Eva; Moser, Michael; Schiltz, Emile; Ueda, Takuya; Betton, Jean-Michel; Müller, Matthias

    2009-06-16

    The twin-arginine translocation (Tat) machinery present in bacterial and thylakoidal membranes is able to transport fully folded proteins. Folding of some Tat precursor proteins requires dedicated chaperones that also sequester the signal sequence during the maturation process. Whether or not signal sequence-binding chaperones are a general prerequisite for all Tat substrate proteins is not known. Here, we have studied the propensity of Tat signal sequences of Escherichia coli to interact with general chaperones and peptidyl-prolyl-cis,trans-isomerases. Site-specific photocross-linking revealed a clear specificity for FK506-binding proteins. Nevertheless transport of the Tat substrate SufI into inverted inner membrane vesicles of E. coli was found to occur in the bona fide absence of any cytosolic chaperone. Our results suggest that in E. coli, cytosolic chaperones are not essential for the twin-arginine-dependent export of cofactor-less substrates. PMID:19432418

  8. Atomic-Resolution Structure of an N(5) Flavin Adduct in D-Arginine Dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Guoxing; Yuan, Hongling; Wang, Siming; Gadda, Giovanni; Weber, Irene T. (GSU)

    2011-09-06

    D-Arginine dehydrogenase (DADH) catalyzes the flavin-dependent oxidative deamination of D-arginine and other D-amino acids to the corresponding imino acids. The 1.07 {angstrom} atomic-resolution structure of DADH crystallized with D-leucine unexpectedly revealed a covalent N(5) flavin adduct, instead of the expected iminoleucine product in the active site. This acyl adduct has been successfully reproduced by photoreduction of DADH in the presence of 4-methyl-2-oxopentanoic acid (ketoleucine). The iminoleucine may be released readily because of weak interactions in the binding site, in contrast to iminoarginine, converted to ketoleucine, which reacts with activated FAD to form the covalently linked acyl adduct.

  9. Atomic-resolution structure of an N5 flavin adduct in D-arginine dehydrogenase.

    Science.gov (United States)

    Fu, Guoxing; Yuan, Hongling; Wang, Siming; Gadda, Giovanni; Weber, Irene T

    2011-07-26

    D-Arginine dehydrogenase (DADH) catalyzes the flavin-dependent oxidative deamination of D-arginine and other D-amino acids to the corresponding imino acids. The 1.07 Å atomic-resolution structure of DADH crystallized with D-leucine unexpectedly revealed a covalent N(5) flavin adduct, instead of the expected iminoleucine product in the active site. This acyl adduct has been successfully reproduced by photoreduction of DADH in the presence of 4-methyl-2-oxopentanoic acid (ketoleucine). The iminoleucine may be released readily because of weak interactions in the binding site, in contrast to iminoarginine, converted to ketoleucine, which reacts with activated FAD to form the covalently linked acyl adduct. PMID:21707047

  10. Selection of Arginine-Rich Anti-Gold Antibodies Engineered for Plasmonic Colloid Self-Assembly

    CERN Document Server

    Jain, Purvi; Narayanan, S Shankara; Sharma, Jadab; Girard, Christian; Dujardin, Erik; Nizak, Clément

    2014-01-01

    Antibodies are affinity proteins with a wide spectrum of applications in analytical and therapeutic biology. Proteins showing specific recognition for a chosen molecular target can be isolated and their encoding sequence identified in vitro from a large and diverse library by phage display selection. In this work, we show that this standard biochemical technique rapidly yields a collection of antibody protein binders for an inorganic target of major technological importance: crystalline metallic gold surfaces. 21 distinct anti-gold antibody proteins emerged from a large random library of antibodies and were sequenced. The systematic statistical analysis of all the protein sequences reveals a strong occurrence of arginine in anti-gold antibodies, which corroborates recent molecular dynamics predictions on the crucial role of arginine in protein/gold interactions. Once tethered to small gold nanoparticles using histidine tag chemistry, the selected antibodies could drive the self-assembly of the colloids onto t...

  11. Arginine-assisted synthesis and catalytic properties of single-crystalline palladium tetrapods.

    Science.gov (United States)

    Fu, Geng-Tao; Jiang, Xian; Wu, Rui; Wei, Shao-Hua; Sun, Dong-Mei; Tang, Ya-Wen; Lu, Tian-Hong; Chen, Yu

    2014-12-24

    Noble metallic nanocrystals (NMNCs) with highly branched morphologies are an exciting new class of nanomaterials because of their great potential application in catalysis, sensing, optics, and electronics originating from their unique structures. Herein, we report a facile water-based method to synthesize high-quality palladium (Pd) tetrapods with the assistance of arginine molecule, which is more economical and environmentally friendly than the previous reported carbon monoxide (CO)-assisted synthesis in the organic system. During the synthesis, arginine molecule plays an essential role in controlling the tetrapod-like morphology. The as-synthesized Pd tetrapods have a potential application in the formic acid (HCOOH)-induced reduction of highly toxic hexavalent chromium (Cr(VI)) owing to their improved catalytic performance for the HCOOH decomposition. PMID:25469763

  12. Solid-state properties and dissolution behaviour of tablets containing co-amorphous indomethacin-arginine

    DEFF Research Database (Denmark)

    Lenz, Elisabeth; Jensen, Katrine Birgitte Tarp; Blaabjerg, Lasse Ingerslev;

    2015-01-01

    Co-amorphous drug formulations provide the possibility to stabilize a drug in its amorphous form by interactions with low molecular weight compounds, e.g. amino acids. Recent studies have shown the feasibility of spray drying as a technique to manufacture co-amorphous indomethacin–arginine in a...... larger production scale. In this work, a tablet formulation was developed for a co-amorphous salt, namely spray dried indomethacin–arginine (SD IND–ARG). The effects of compaction pressure on tablet properties, physical stability and dissolution profiles under non-sink conditions were examined....... Dissolution profiles of tablets with SD IND–ARG (TAB SD IND–ARG) were compared to those of tablets containing a physical mixture of crystalline IND and ARG (TAB PM IND–ARG) and to the dissolution of pure spray dried powder. Concerning tableting, the developed formulation allowed for the preparation of tablets...

  13. Arginine Vasopressin V1a Receptor Antagonist Impairs Maternal Memory in Rats

    OpenAIRE

    Nephew, Benjamin C.; Bridges, Robert S.

    2008-01-01

    Primiparous female rats rapidly respond to foster pups following an extended separation from pups after an initial maternal experience. This consolidation of maternal behavior has been referred to as maternal memory. The neurochemical regulation of maternal memory is not clearly understood. One neuropeptide that may mediate maternal memory is arginine vasopressin (AVP), a neuropeptide which is modulated around the time of parturition and has an established role in learning and memory processe...

  14. Comparison of L-Arginine and Hydroxyurea Interactractions with Transitional Metal Ions.

    Directory of Open Access Journals (Sweden)

    Sangeeta Parab

    2015-11-01

    Full Text Available No* is a free radical with one free electron and as such it is very highly reactive and particularly it interacts with transitional metals. Nitric oxide, gas is an important signaling molecule in the body of mammals, including humans and is an extremely important intermediate in chemical industry In biological systems there are many enzymes, which contain transitional elements like iron, copper and manganese, which are the most probable sites for nitric oxide to react. Such type of interactions results in considerable mod ification of the enzyme functions resulting pathological and even genetic disorders. This needs a critical amount of nitric oxide in the system for proper functioning. To observe the effects of NO*, various NO* donor compounds are used. Hydroxyurea (HU is shown to increase the levels of NO*.L- arginine is one of the non - essential amino acids. In the body L- arginine is used to make nitric oxide, which reduces blood vessel stiffness, increases blood flow and improves blood vessel function. The visible spectra of some transitional metals Cu, Fe(II,Fe(III,Cr, Mn, Ni have been studied individually in presence of hydroxyurea (HU with varying amounts .The spectra are also studied for the effect of varying amounts of metal ion on hydroxyurea. To observe how arginine itself acts on transitional metal ions. Even effect of Hydroxyurea on metal - arginine binding is also studied. The evaluation of these spectra is carried out for its binding parameters with the help of scatchard plots. The work has revealed certain very significant and interesting data which can have a lot of bearing on many chemical, biological and environmental aspects.

  15. Unique Photobleaching Phenomena of the Twin-Arginine Translocase Respiratory Enzyme Chaperone DmsD

    OpenAIRE

    Rivardo, Fabrizio; Leach, Thorin G.H.; Chan, Catherine S.; Winstone, Tara M. L.; Ladner, Carol L.; Sarfo, Kwabena J.; Turner, Raymond J.

    2014-01-01

    DmsD is a chaperone of the redox enzyme maturation protein family specifically required for biogenesis of DMSO reductase in Escherichia coli. It exists in multiple folding forms, all of which are capable of binding its known substrate, the twin-arginine leader sequence of the DmsA catalytic subunit. It is important for maturation of the reductase and targeting to the cytoplasmic membrane for translocation. Here, we demonstrate that DmsD exhibits an irreversible photobleaching phenomenon upon ...

  16. Effect of L- Arginine On Electrocardiographic Changes Induced By Hypercholesterolemia And Isoproterenol In Rabbits

    OpenAIRE

    Kumar, Pradeep; Goyal, Manish; Agarwal, J L

    2009-01-01

    Hypercholesterolemia, a well-known cardiovascular risk factor, is associated with prolonged action potential duration, longer QTc intervals (rate controlled QT interval), suggested that Hypercholesterolemia may have a direct effect on ventricular repolarization. Hypercholesterolemia was induced in rabbits and L-arginine was given orally to animals for sixteen weeks. The isoproterenol was injected in all the animals to produce electrocardiographic changes. ECG was recorded in lead II at start ...

  17. Surprising Arginine Biosynthesis: a Reappraisal of the Enzymology and Evolution of the Pathway in Microorganisms

    OpenAIRE

    Xu, Ying; Labedan, Bernard; Glansdorff, Nicolas

    2007-01-01

    Summary: Major aspects of the pathway of de novo arginine biosynthesis via acetylated intermediates in microorganisms must be revised in light of recent enzymatic and genomic investigations. The enzyme N-acetylglutamate synthase (NAGS), which used to be considered responsible for the first committed step of the pathway, is present in a limited number of bacterial phyla only and is absent from Archaea. In many Bacteria, shorter proteins related to the Gcn5-related N-acetyltransferase family ap...

  18. Arginine and proline applied as food additives stimulate high freeze tolerance in larvae of Drosophila melanogaster.

    Science.gov (United States)

    Koštál, Vladimír; Korbelová, Jaroslava; Poupardin, Rodolphe; Moos, Martin; Šimek, Petr

    2016-08-01

    The fruit fly Drosophila melanogaster is an insect of tropical origin. Its larval stage is evolutionarily adapted for rapid growth and development under warm conditions and shows high sensitivity to cold. In this study, we further developed an optimal acclimation and freezing protocol that significantly improves larval freeze tolerance (an ability to survive at -5°C when most of the freezable fraction of water is converted to ice). Using the optimal protocol, freeze survival to adult stage increased from 0.7% to 12.6% in the larvae fed standard diet (agar, sugar, yeast, cornmeal). Next, we fed the larvae diets augmented with 31 different amino compounds, administered in different concentrations, and observed their effects on larval metabolomic composition, viability, rate of development and freeze tolerance. While some diet additives were toxic, others showed positive effects on freeze tolerance. Statistical correlation revealed tight association between high freeze tolerance and high levels of amino compounds involved in arginine and proline metabolism. Proline- and arginine-augmented diets showed the highest potential, improving freeze survival to 42.1% and 50.6%, respectively. Two plausible mechanisms by which high concentrations of proline and arginine might stimulate high freeze tolerance are discussed: (i) proline, probably in combination with trehalose, could reduce partial unfolding of proteins and prevent membrane fusions in the larvae exposed to thermal stress (prior to freezing) or during freeze dehydration; (ii) both arginine and proline are exceptional among amino compounds in their ability to form supramolecular aggregates which probably bind partially unfolded proteins and inhibit their aggregation under increasing freeze dehydration. PMID:27489218

  19. Arginine vasopressin versus norepinephrine: will the stronger one win the race?

    OpenAIRE

    Ertmer, Christian; Bone, Hans-Georg; Westphal, Martin

    2006-01-01

    In the current issue of Critical Care, Friesenecker and colleagues present a well-designed comparative study on the microvascular effects of arginine vasopressin (AVP) and norepinephrine (NE) in a physiological, unanesthetized hamster model. The authors clearly demonstrate that AVP, but not NE, has marked vasoconstrictive effects on large arterioles, whereas the impact on small arterioles is comparable for both vasopressors. However, it remains unclear if these results, per se, reflect a stro...

  20. Levels of arginine-vasopressin in cerebrospinal fluid during passive avoidance behavior in rats

    OpenAIRE

    Kloet, E.R. de; Laczi, F.; Gaffori, O.; Fekete, M.; Wied, D. de

    1984-01-01

    The concentration of immunoreactive arginine-vasopressin (IR-AVP) was measured in the cerebrospinal fluid (CSF) during acquisition and retention of passive avoidance behavior. IR-AVP level in CSF of male Wistar rats immediately after the learning trial was increased; the rate of which was related to the intensity of the electric footschock during the learning trial and the avoidance latency as measured 1 day after the learning trial. Immediately after the 24 h retention test IR-AVP levels wer...

  1. Arteriolar vasoconstrictive response: comparing the effects of arginine vasopressin and norepinephrine

    OpenAIRE

    Friesenecker, Barbara E; Tsai, Amy G; Martini, Judith; Ulmer, Hanno; Wenzel, Volker; Hasibeder, Walter R; Intaglietta, Marcos; Dünser, Martin W

    2006-01-01

    INTRODUCTION: This study was designed to examine differences in the arteriolar vasoconstrictive response between arginine vasopressin (AVP) and norepinephrine (NE) on the microcirculatory level in the hamster window chamber model in unanesthetized, normotonic hamsters using intravital microscopy. It is known from patients with advanced vasodilatory shock that AVP exerts strong additional vasoconstriction when incremental dosage increases of NE have no further effect on mean arterial blood pre...

  2. Methylation of CenH3 arginine 37 regulates kinetochore integrity and chromosome segregation

    OpenAIRE

    Samel, Anke; Cuomo, Alessandro; Bonaldi, Tiziana; Ehrenhofer-Murray, Ann E

    2012-01-01

    Centromeres of eukaryotic chromosomes mark the site for kinetochore formation and microtubule attachment and are essential for accurate chromosome segregation. Although centromere identity is defined by the presence of the histone H3 variant CenH3/centromere protein A (CENP-A), little is known about how epigenetic modifications on CenH3 might regulate kinetochore assembly and centromere function. Here we show that CENP-A from Saccharomyces cerevisiae, termed Cse4, is methylated on arginine 37...

  3. A mutation in the human phospholamban gene, deleting arginine 14, results in lethal, hereditary cardiomyopathy

    OpenAIRE

    Haghighi, Kobra; Kolokathis, Fotis; Gramolini, Anthony O.; Waggoner, Jason R.; Pater, Luke; Lynch, Roy A.; Fan, Guo-Chang; Tsiapras, Dimitris; Parekh, Rohan R.; Dorn, Gerald W., II; MacLennan, David H.; Kremastinos, Dimitrios Th; Kranias, Evangelia G.

    2006-01-01

    The sarcoplasmic reticulum Ca2+-cycling proteins are key regulators of cardiac contractility, and alterations in sarcoplasmic reticulum Ca2+-cycling properties have been shown to be causal of familial cardiomyopathies. Through genetic screening of dilated cardiomyopathy patients, we identified a previously uncharacterized deletion of arginine 14 (PLN-R14Del) in the coding region of the phospholamban (PLN) gene in a large family with hereditary heart failure. No homozygous individuals were ide...

  4. Degradation of Arginine and Other Amino Acids by Eubacterium nodatum ATCC 33099

    OpenAIRE

    Uematsu, H.; Hoshino, E.

    2011-01-01

    The utilisation of a total of 20 amino acids by Eubacterium nodatum, a predominant asaccharolytic anaerobe isolated from human periodontal pockets, was studied. Washed cells of the microorganism produced substantial amounts of acetate, butyrate and ammonia from lysine, and butyrate and ammonia from arginine as main products under anaerobic conditions. They also produced a small amount of formate from histidine. Metabolic products were not detected from any of the other 17 amino acids. These r...

  5. The development of poly-L-arginine-coated liposomes for gene delivery

    OpenAIRE

    Opanasopit P; Tragulpakseerojn J; Apirakaramwong A; Ngawhirunpat T; Rojanarata T; Ruktanonchai U

    2011-01-01

    Praneet Opanasopit1, Jintana Tragulpakseerojn1, Auayporn Apirakaramwong1, Tanasait Ngawhirunpat1, Theerasak Rojanarata1, Uracha Ruktanonchai21Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand; 2National Nanotechnology Center, Thailand Science Park, Pathumthani, Thailand Abstract: In this study, liposomes coated with cationic polymers, poly-L-arginine (PLA), were assessed as a promising gene transfer system in human cervical carcinoma (HeLa) cells and human h...

  6. Arginine ADP-ribosylation mechanism based on structural snapshots of iota-toxin and actin complex

    OpenAIRE

    Tsurumura, Toshiharu; Tsumori, Yayoi; Qiu, Hao; Oda, Masataka; Sakurai, Jun; Nagahama, Masahiro; Tsuge, Hideaki

    2012-01-01

    Clostridium perfringens iota-toxin (Ia) mono-ADP ribosylates Arg177 of actin, leading to cytoskeletal disorganization and cell death. To fully understand the reaction mechanism of arginine-specific mono-ADP ribosyl transferase, the structure of the toxin-substrate protein complex must be characterized. Recently, we solved the crystal structure of Ia in complex with actin and the nonhydrolyzable NAD+ analog βTAD (thiazole-4-carboxamide adenine dinucleotide); however, the structures of the NAD+...

  7. Efficacy L-Arginine In Patients With Nonalcoholic Steatohepatitis Associated With Metabolic Syndrome

    OpenAIRE

    Oleksandr Fediv; Volodymyr Shevchuk; Oksana Olinyk

    2015-01-01

    Abstract Background and Purpose Recent research in the field of hematology indicate that among the many pathogenic mechanisms of development and progression of nonalcoholic steatohepatitis NASH which occurs on the background of the metabolic syndrome an important role is played by endothelial dysfunction and violations of haemocoagulation. The aim of this research was to study the effectiveness of L-arginine as it corrects endothelial dysfunction and disorders of homeostasis haemocoagulation ...

  8. Arginine-Rich Cationic Polypeptides Amplify Lipopolysaccharide-Induced Monocyte Activation

    OpenAIRE

    Bosshart, Herbert; Heinzelmann, Michael

    2002-01-01

    The human neutrophil-derived cationic protein CAP37, also known as azurocidin or heparin-binding protein, enhances the lipopolysaccharide (LPS)-induced release of tumor necrosis factor alpha (TNF-α) in isolated human monocytes. We measured the release of the proinflammatory cytokine interleukin-8 (IL-8) in human whole blood and found that in addition to CAP37, other arginine-rich cationic polypeptides, such as the small structurally related protamines, enhance LPS-induced monocyte activation....

  9. A novel virulence strategy for Pseudomonas aeruginosa mediated by an autotransporter with arginine-specific aminopeptidase activity

    OpenAIRE

    Luckett, Jeni C. A.; Owen Darch; Chase Watters; Manal Abuoun; Victoria Wright; Esteban Paredes-Osses; Jenny Ward; Hana Goto; Stephan Heeb; Stéphanie Pommier; Rumbaugh, Kendra P.; Miguel Cámara; Hardie, Kim R.

    2012-01-01

    Author Summary We present a new Pseudomonas aeruginosa virulence factor that promotes chronic skin wound infections. We propose the name AaaA for this cell-surface tethered autotransporter. This arginine-specific aminopeptidase confers a growth advantage upon P. aeruginosa, providing a fitness advantage by creating a supply of arginine in chronic wounds where oxygen availability is limited and biofilm formation is involved. To our knowledge, this is the first mechanistic evidence linking the ...

  10. Nitric Oxide Synthase Inhibition by NG-Nitro-l-Arginine Methyl Ester Inhibits Tumor-Induced Angiogenesis in Mammary Tumors

    OpenAIRE

    Jadeski, Lorraine C.; Lala, Peeyush K.

    1999-01-01

    Using a murine breast cancer model, we earlier found a positive correlation between the expression of nitric oxide synthase (NOS) and tumor progression; treatment with inhibitors of NOS, NG-methyl-l-arginine (NMMA) and NG-nitro-l-arginine methyl ester (L-NAME), had antitumor and antimetastatic effects that were partly attributed to reduced tumor cell invasiveness. In the present study, we used a novel in vivo model of tumor angiogenesis using subcutaneous implants of tumor cells suspended in ...

  11. Acute L-arginine alpha ketoglutarate supplementation fails to improve muscular performance in resistance trained and untrained men

    OpenAIRE

    Wax Benjamin; Kavazis Andreas N; Webb Heather E; Brown Stanley P

    2012-01-01

    Abstract Background Dietary supplements containing L-arginine are marketed to improve exercise performance, but the efficacy of such supplements is not clear. Therefore, this study examined the efficacy of acute ingestion of L-arginine alpha-ketoglutarate (AAKG) muscular strength and endurance in resistance trained and untrained men. Methods Eight resistance trained and eight untrained healthy males ingested either 3000mg of AAKG or a placebo 45 minutes prior to a resistance exercise protocol...

  12. Comparison of the effect of topical versus systemic L-arginine on wound healing in acute incisional diabetic rat model

    OpenAIRE

    Alireza Zandifar; Sima Seifabadi; Ehsan Zandifar; Sajedeh Sohrabi Beheshti; Abolfazl Aslani; Shaghayegh Haghjooy Javanmard

    2015-01-01

    Background: Diabetes is associated with endothelial dysfunction and impaired wound healing. The amino acid L-arginine is the only substrate for nitric oxide (NO) synthesis. The purpose of this study was to compare the topical versus systemic L-arginine treatment on total nitrite (NO x ) and vascular endothelial growth factor (VEGF) concentrations in wound fluid and rate of wound healing in an acute incisional diabetic wound model. Materials and Methods: A total of 56 Sprague-Dawley rats were ...

  13. A Selective V1A Receptor Agonist, Selepressin, Is Superior to Arginine Vasopressin and to Norepinephrine in Ovine Septic Shock*

    OpenAIRE

    He, Xinrong; Su, Fuhong; Taccone, Fabio Silvio; Laporte, Régent; Kjølbye, Anne Louise; Zhang, Jing; Xie, Keliang; Moussa, Mouhamed Djahoum; Reinheimer, Torsten Michael; Vincent, Jean-Louis

    2015-01-01

    Objective: Selective vasopressin V1A receptor agonists may have advantages over arginine vasopressin in the treatment of septic shock. We compared the effects of selepressin, a selective V1A receptor agonist, arginine vasopressin, and norepinephrine on hemodynamics, organ function, and survival in an ovine septic shock model. Design: Randomized animal study. Setting: University hospital animal research laboratory. Subjects: Forty-six adult female sheep. Interventions: Fecal peritonitis was in...

  14. Effect of L-arginine on renal blood flow in normal subjects and patients with hypoxic chronic obstructive pulmonary disease.

    OpenAIRE

    Howes, T. Q.; Keilty, S. E.; Maskrey, V. L.; Deane, C. R.; Baudouin, S. V.; Moxham, J

    1996-01-01

    BACKGROUND: L-arginine is the precursor of endothelium derived nitric oxide (NO) and increasing the available substrate may increase the production of NO. This has been shown by local infusion in peripheral vascular beds but there are few studies of the effects during systemic infusion. Renal vasoconstriction is known to be important in the pathogenesis of cor pulmonale in patients with hypoxic chronic obstructive pulmonary disease (COPD). The effects of a systemic infusion of L-arginine on r...

  15. Using FT-NIR spectroscopy technique to determine arginine content in fermented Cordyceps sinensis mycelium.

    Science.gov (United States)

    Xie, Chuanqi; Xu, Ning; Shao, Yongni; He, Yong

    2015-10-01

    This research investigated the feasibility of using Fourier transform near-infrared (FT-NIR) spectral technique for determining arginine content in fermented Cordyceps sinensis (C. sinensis) mycelium. Three different models were carried out to predict the arginine content. Wavenumber selection methods such as competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the most important wavenumbers and reduce the high dimensionality of the raw spectral data. Only a few wavenumbers were selected by CARS and CARS-SPA as the optimal wavenumbers, respectively. Among the prediction models, CARS-least squares-support vector machine (CARS-LS-SVM) model performed best with the highest values of the coefficient of determination of prediction (Rp(2)=0.8370) and residual predictive deviation (RPD=2.4741), the lowest value of root mean square error of prediction (RMSEP=0.0841). Moreover, the number of the input variables was forty-five, which only accounts for 2.04% of that of the full wavenumbers. The results showed that FT-NIR spectral technique has the potential to be an objective and non-destructive method to detect arginine content in fermented C. sinensis mycelium. PMID:26010565

  16. Study on mutual interactions and electronic structures of hyaluronan with Lysine, 6-Aminocaproic acid and Arginine.

    Science.gov (United States)

    Chytil, Martin; Trojan, Martin; Kovalenko, Alexander

    2016-05-20

    Interactions between polyelectrolytes and oppositely charged surfactants have been in a great interest for several decades, yet the conventional surfactants may cause a problem in medical applications. Interactivity between polysaccharide hyaluronan (HA) and amino acids Lysine, 6-Aminocaproic acid (6-AcA), and Arginine as an alternative system is reported. The interactions were investigated by means of rheology and electric conductance and the electronic structures were explored by the density functional theory (DFT). Lysine exhibits the strongest interaction of all, which was manifested, e.g. by nearly 6-time drop of the initial viscosity comparing with only 1.3-time lower value in the case of 6-AcA. Arginine interaction with HA was surprisingly weaker in terms of viscosity than that of Lysine due to a lower and delocalized charge density on its guanidine group. According to the DFT calculations, the binding of Lysine to HA was found to be more flexible, while Arginine creates more rigid structure with HA. PMID:26917367

  17. Effect of oral arginine supplementation on GH secretion and lipid metabolism in Wistar trained rats

    Directory of Open Access Journals (Sweden)

    E. Luciano

    2009-01-01

    Full Text Available The Oral Arginine Supplementation (OAS and exercise are able to modify the secretion of the Growth Hormone (GH that stimulates the lipid metabolism. The aim of the study was to verify the effect of the OAS, the aerobic exercise and the combination of the OAS with the aerobic exercise on the GH secretion and lipid metabolism in rats. The sample was composted for 40 male wistar rats, divided in four groups: Sedentary control (SC, sedentary arginine (SA, trained control (TC and trained arginine (TA. The AS and AT received the oral supplementation in alternated days and the groups CT and AT realized swimming exercise for 1hour/day with overload equivalent to 5% of body mass five days per week during 4 weeks. The concentrations of GH were significantly difference between the sedentary groups (SC and AS and (TC and AT and the lipid metabolism did not change throughout all groups. In conclusions, aerobic physical training did not modify the lipid metabolism and diminishes the values of GH concentration and the OAS did not modify the concentration of GH in Wistar rats.

  18. Arginine and antioxidant supplement on performance in elderly male cyclists: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Carpenter Catherine L

    2010-03-01

    Full Text Available Abstract Background Human exercise capacity declines with advancing age. These changes often result in loss of physical fitness and more rapid senescence. Nitric oxide (NO has been implicated in improvement of exercise capacity through vascular smooth muscle relaxation in both coronary and skeletal muscle arteries, as well as via independent mechanisms. Antioxidants may prevent nitric oxide inactivation by oxygen free radicals. The purpose of this study was to investigate the effects of an L-arginine and antioxidant supplement on exercise performance in elderly male cyclists. Methods This was a two-arm prospectively randomized double-blinded and placebo-controlled trial. Sixteen male cyclists were randomized to receive either a proprietary supplement (Niteworks®, Herbalife International Inc., Century City, CA or a placebo powder. Exercise parameters were assessed by maximal incremental exercise testing performed on a stationary cycle ergometer using breath-by-breath analysis at baseline, week one and week three. Results There was no difference between baseline exercise parameters. In the supplemented group, anaerobic threshold increased by 16.7% (2.38 ± 0.18 L/min, p 2 max between control and intervention groups at either week 1 or week 3 by comparison to baseline. Conclusion An arginine and antioxidant-containing supplement increased the anaerobic threshold at both week one and week three in elderly cyclists. No effect on VO2 max was observed. This study indicated a potential role of L-arginine and antioxidant supplementation in improving exercise performance in elderly.

  19. Promoting siRNA delivery via enhanced cellular uptake using an arginine-decorated amphiphilic dendrimer

    Science.gov (United States)

    Liu, Xiaoxuan; Liu, Cheng; Zhou, Jiehua; Chen, Chao; Qu, Fanqi; Rossi, John J.; Rocchi, Palma; Peng, Ling

    2015-02-01

    RNA interference (RNAi) with small interfering RNA (siRNA) is expected to offer an attractive means to specifically and efficiently silence disease-associated genes for treating various diseases provided that safe and efficient delivery systems are available. In this study, we have established an arginine-decorated amphiphilic dendrimer composed of a hydrophobic alkyl chain and a hydrophilic PAMAM dendron bearing arginine terminals as nonviral vector for siRNA delivery. Indeed, this dendrimer proved to be very effective at delivering siRNAs in human prostate cancer PC-3 cells and in human hematopoietic CD34+ stem cells, leading to improved gene silencing compared to the corresponding nonarginine decorated dendrimer. Further investigation confirmed that this dendrimer was granted with the capacity to form stable nanoparticles with siRNA and significantly enhance cellular uptake of siRNA. In addition, this dendrimer revealed no discernible cytotoxicity. All these findings demonstrate that decoration of the dendrimer surface with arginine residues is indeed a useful strategy to improve the delivery ability of dendrimers.

  20. Kinetics for Cu(2+) induced Sepia pharaonis arginine kinase inactivation and aggregation.

    Science.gov (United States)

    Shi, Xiao-Yu; Zhang, Li-Li; Wu, Feng; Fu, Yang-Yong; Yin, Shang-Jun; Si, Yue-Xiu; Park, Yong-Doo

    2016-10-01

    Arginine kinase plays an important role in cellular energy metabolism and is closely related to the environmental stress response in marine invertebrates. We studied the Cu(2+)-mediated inhibition and aggregation of Sepia pharaonis arginine kinase (SPAK) and found that Cu(2+) markedly inhibited the SPAK activity along with mixed-type inhibition against the arginine substrate and noncompetitive inhibition against the ATP cofactor. Spectrofluorimetry results showed that Cu(2+) induced a tertiary structure change in SPAK, resulting in exposure of the hydrophobic surface and increased aggregation. Cu(2+)-mediated SPAK aggregation followed first-order kinetics consistent with monophasic and a biphasic processes. Addition of osmolytes, including glycine and proline, effectively blocked SPAK aggregation and restored SPAK activity. Our results demonstrated the effects of Cu(2+) on SPAK catalytic function, conformation, and aggregation, as well as the protective effects of osmolytes on SPAK folding. This study provided important insights into the role of Cu(2+) as a negative effector of the S. pharaonis metabolic enzyme AK and the possible responses of cephalopods to unfavorable environmental conditions. PMID:27318110

  1. Mass spectrometry-based identification and characterisation of lysine and arginine methylation in the human proteome.

    Science.gov (United States)

    Bremang, Michael; Cuomo, Alessandro; Agresta, Anna Maria; Stugiewicz, Magdalena; Spadotto, Valeria; Bonaldi, Tiziana

    2013-09-01

    Protein methylation is a post-translational modification (PTM) by which a variable number of methyl groups are transferred to lysine and arginine residues within proteins. Despite increased interest in this modification due to its reversible nature and its emerging role in a diverse set of biological pathways beyond chromatin, global identification of protein methylation has remained an unachieved goal. To characterise sites of lysine and arginine methylation beyond histones, we employed an approach that combines heavy methyl stable isotope labelling by amino acids in cell culture (hmSILAC) with high-resolution mass spectrometry-based proteomics. Through a broad evaluation of immuno-affinity enrichment and the application of two classical protein separation techniques prior to mass spectrometry, to nucleosolic and cytosolic fractions separately, we identified a total of 501 different methylation types, on 397 distinct lysine and arginine sites, present on 139 unique proteins. Our results considerably extend the number of known in vivo methylation sites and indicate their significant presence on several protein complexes involved at all stages of gene expression, from chromatin remodelling and transcription to splicing and translation. In addition, we describe the potential of the hmSILAC approach for accurate relative quantification of methylation levels between distinct functional states. PMID:23748837

  2. Caries-free subjects have high levels of urease and arginine deiminase activity

    Directory of Open Access Journals (Sweden)

    Evelyn REYES

    2014-06-01

    Full Text Available Objectives: This study investigated the relationship between urease and arginine deiminase system (ADS activities and dental caries through a cross-sectional study. Material and Methods: Urease and ADS activities were measured in saliva and plaque samples from 10 caries-free subjects and 13 caries-active. Urease activity was obtained from the ammonia produced by incubation of plaque and saliva samples in urea. ADS activity was obtained from the ammonia generated by the arginine-HCl and Tris-maleate buffer. Specific activity was defined as micromoles of ammonia per minute per milligram of protein. Shapiro-Wilk statistical test was used to analyze the distribution of the data, and Mann-Whitney test was used to determine the significance of the data. Results: The specific urease activity in saliva and plaque was significantly higher in individuals with low DMFT scores. ADS activity in saliva (6.050 vs 1.350, p=0.0154 and plaque (8.830 vs 1.210, p=0.025 was also higher in individuals with low DMFT scores. Conclusions: Caries-free subjects had a higher ammonia generation activity by urease and arginine deiminase system for both saliva and plaque samples than low caries-active subjects. High levels of alkali production in oral environment were related to caries-free subjects.

  3. Plasma properties

    International Nuclear Information System (INIS)

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  4. The Effects Of L-Arginine And L-Name On Coronary Flow And Oxidative Stress In Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Sobot Tanja

    2015-12-01

    Full Text Available The aim of this experimental study was to assess the effects of the acute administration of L-arginine alone and in combination with L-NAME (a non-selective NO synthase inhibitor on the coronary flow and oxidative stress markers in isolated rat hearts. The experimental study was performed on hearts isolated from Wistar albino rats (n=12, male, 8 weeks old, body mass of 180-200 g. Retrograde perfusion of the isolated preparations was performed using a modified method according to the Langendorff technique with a gradual increase in the perfusion pressure (40–120 cmH2O. The following values were measured in the collected coronary effluents: coronary flow, released nitrites (NO production marker, superoxide anion radical and the index of lipid peroxidation (measured as thiobarbiturate reactive substances. The experimental protocol was performed under controlled conditions, followed by the administration of L-arginine alone (1 mmol and L-arginine (1 mmol + L-NAME (30 μmol. The results indicated that L-arginine did not significantly increase the coronary flow or the release of NO, TBARS and the superoxide anion radical. These effects were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive effect. Hence, the results of our study do not demonstrate significant effects of L-arginine administration on the coronary flow and oxidative stress markers in isolated rat hearts.

  5. Influence of phenolic compounds on the growth and arginine deiminase system in a wine lactic acid bacterium

    Directory of Open Access Journals (Sweden)

    María R. Alberto

    2012-03-01

    Full Text Available The influence of seven phenolic compounds, normally present in wine, on the growth and arginine deiminase system (ADI of Lactobacillus hilgardii X1B, a wine lactic acid bacterium, was established. This system provides energy for bacterial growth and produces citrulline that reacts with ethanol forming the carcinogen ethyl carbamate (EC, found in some wines. The influence of phenolic compounds on bacterial growth was compound dependent. Growth and final pH values increased in presence of arginine. Arginine consumption decreased in presence of protocatechuic and gallic acids (31 and 17%, respectively and increased in presence of quercetin, rutin, catechin and the caffeic and vanillic phenolic acids (between 10 and 13%, respectively. ADI enzyme activities varied in presence of phenolic compounds. Rutin, quercetin and caffeic and vanillic acids stimulated the enzyme arginine deiminase about 37-40%. Amounts of 200 mg/L gallic and protocatechuic acids inhibited the arginine deiminase enzyme between 53 and 100%, respectively. Ornithine transcarbamylase activity was not modified at all concentrations of phenolic compounds. As gallic and protocatechuic acids inhibited the arginine deiminase enzyme that produces citrulline, precursor of EC, these results are important considering the formation of toxic compounds.

  6. Monomeric Corynebacterium glutamicum N-acetyl glutamate kinase maintains sensitivity to L-arginine but has a lower intrinsic catalytic activity.

    Science.gov (United States)

    Huang, Yuanyuan; Li, Cheng; Zhang, Hao; Liang, Shuli; Han, Shuangyan; Lin, Ying; Yang, Xiaorong; Zheng, Suiping

    2016-02-01

    N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine, and L-arginine-sensitive NAGK typically has hexameric architecture. Defining the relationship between this architecture and L-arginine inhibition can provide a foundation to identify the key amino acids involved in the allosteric regulation network of L-arginine. In the present study, the key amino acids in the N-terminal helix (N-helix) of Corynebacterium glutamicum (Cg) NAGK required for hexamer formation were determined using structural homology modeling and site-directed mutagenesis. It was also verified that hexameric architecture is required for the positive cooperativity of inhibition by L-arginine and for efficient catalysis, but that it is not the determinant of inhibition by L-arginine. Monomeric mutants retained a similar sensitivity to L-arginine as the hexameric form, indicating that monomers contain an independent, sensitive signal transduction network of L-arginine to mediate allosteric regulation. Mutation studies of CgNAGKs also revealed that amino acid residues 18-23 of the N-helix are required for inhibition by L-arginine, and that E19 may be an essential amino acid influencing the apparent affinity of L-arginine. Collectively, these studies may illuminate the basic mechanism of metabolic homeostasis of C. glutamicum. PMID:26512006

  7. Plasma accelerators

    International Nuclear Information System (INIS)

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  8. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  9. Revisiting the plasma sheath—dust in plasma sheath

    Science.gov (United States)

    Das, G. C.; Deka, R.; Bora, M. P.

    2016-04-01

    In this work, we have considered the formation of warm plasma sheath in the vicinity of a wall in a plasma with considerable presence of dust particles. As an example, we have used the parameters relevant in case of plasma sheath formed around surfaces of various solid bodies in space, though the results obtained in this work can be applied to any other physical situation such as laboratory plasma. In the ion-acoustic time scale, we neglect the dust dynamics. The dust particles affect the sheath dynamics by affecting the Poisson equation which determines the plasma potential in the sheath region. It is important to note that our calculations are valid only when the amount of dust particles is not sufficient so as to affect the plasma dynamics in the dust-acoustic time scale, but enough to affect the plasma sheath. We have assumed the current to a dust particle to be balanced throughout the analysis. This makes the grain potential dependent on plasma potential, which is then incorporated into the Poisson equation. The resultant numerical model becomes an initial value problem, which is described by a 1-D integro-differential equation, which is then solved self-consistently by incorporating the change in plasma potential caused by inclusion of the dust potential in the Poisson equation.

  10. Response Prediction and Influence of Tolvaptan in Chronic Heart Failure Patients Considering the Interaction of the Renin-Angiotensin-Aldosterone System and Arginine Vasopressin.

    Science.gov (United States)

    Kadota, Muneyuki; Ise, Takayuki; Yagi, Shusuke; Iwase, Takashi; Akaike, Masashi; Ueno, Rie; Kawabata, Yutaka; Hara, Tomoya; Ogasawara, Kozue; Bando, Mika; Bando, Sachiko; Matsuura, Tomomi; Yamaguchi, Koji; Yamada, Hirotsugu; Soeki, Takeshi; Wakatsuki, Tetsuzo; Sata, Masataka

    2016-07-27

    The renin-angiotensin-aldosterone system (RAAS) and arginine vasopressin (AVP) regulate body fluids. Although conventional diuretics have been used for treating heart failure, they activate RAAS and exacerbate renal function. Tolvaptan, a newly developed vasopressin-2 receptor antagonist, elicits aquaresis and improves volume overload in heart failure patients, however, the predictors of tolvaptan effectiveness and the influence on the RAAS and renal function according to tolvaptan therapy are not established. We evaluated 26 chronic heart failure patients receiving therapy with 15 mg/day tolvaptan and examined their laboratory and urinary data before and after tolvaptan therapy. A response to tolvaptan was defined as a body weight decrease by more than 2 kg in a week and a urine volume increase by 500 mL/ day compared with that before tolvaptan administration. Body weight, urine volume, and brain natriuretic peptide levels significantly improved (P < 0.05), without any worsening of renal function represented by serum creatinine, sodium, and potassium. Moreover, no significant changes were observed in the plasma renin activity and plasma aldosterone concentration (PAC). In the responder group, urine osmolality before tolvaptan administration was significantly higher (P < 0.05) but declined significantly after tolvaptan administration (P < 0.05). The AVP/PAC ratio before administration was positively correlated with the efficacy of tolvaptan. Tolvaptan treatment could prevent RAAS activation in chronic heart failure patients. Moreover, monitoring the AVP/PAC ratio may be useful in predicting the tolvaptan response. PMID:27357439

  11. L-Arginine Supplementation in Type II Diabetic Rats Preserves Renal Function and Improves Insulin Sensitivity by Altering the Nitric Oxide Pathway

    Directory of Open Access Journals (Sweden)

    Taylor Claybaugh

    2014-01-01

    Full Text Available Rat studies demonstrated that type II diabetes mellitus (T2DM decreases both the production and bioavailability of nitric oxide (NO. L-arginine (LA provides the precursor for the production of NO. We hypothesized that LA dietary supplementation will preserve NO production via endothelial nitric oxide synthase (eNOS causing renal microvascular vasodilation and increased glomerular blood flow and thus increasing glomerular filtration rate (GFR. This would impede the formation of reactive oxygen species which contributes to cell damage and death. LA supplementation preserved GFR in the treated diabetic rats compared to untreated diabetic rats. We provide evidence that this effect may be due to increased levels of eNOS and urinary cyclic guanosine monophosphate, which leads to renal microvascular vasodilation. Plasma nitrotyrosine was decreased in the LA treated rats; however, plasma nitrite levels remained unaffected as expected. Marked improvements in glucose tolerance were also observed in the LA treated diabetic rats. These results demonstrate that LA supplementation preserves NO activity and may delay the onset of insulin resistance and renal dysfunction during hyperglycemic stress. These results suggest the importance of the NO pathway in consequent renal dysfunction and in the development of insulin resistance in diabetic rats.

  12. 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...

  13. Arginase treatment prevents the recovery of canine lymphoma and osteosarcoma cells resistant to the toxic effects of prolonged arginine deprivation.

    Directory of Open Access Journals (Sweden)

    James W Wells

    Full Text Available Rapidly growing tumor cells require a nutrient-rich environment in order to thrive, therefore, restricting access to certain key amino acids, such as arginine, often results in the death of malignant cells, which frequently display defective cell cycle check-point control. Healthy cells, by contrast, become quiescent and remain viable under arginine restriction, displaying full recovery upon return to arginine-rich conditions. The use of arginase therapy to restrict available arginine for selectively targeting malignant cells is currently under investigation in human clinical trials. However, the suitability of this approach for veterinary uses is unexplored. As a prelude to in vivo studies in canine malignancies, we examined the in vitro effects of arginine-deprivation on canine lymphoid and osteosarcoma cell lines. Two lymphoid and 2 osteosarcoma cell lines were unable to recover following 6 days of arginine deprivation, but all remaining cell lines displayed full recovery upon return to arginine-rich culture conditions. These remaining cell lines all proved susceptible to cell death following the addition of arginase to the cultures. The lymphoid lines were particularly sensitive to arginase, becoming unrecoverable after just 3 days of treatment. Two of the osteosarcoma lines were also susceptible over this time-frame; however the other 3 lines required 6-8 days of arginase treatment to prevent recovery. In contrast, adult progenitor cells from the bone marrow of a healthy dog were able to recover fully following 9 days of culture in arginase. Over 3 days in culture, arginase was more effective than asparaginase in inducing the death of lymphoid lines. These results strongly suggest that short-term arginase treatment warrants further investigation as a therapy for lymphoid malignancies and osteosarcomas in dogs.

  14. Arginase and Arginine Decarboxylase - Where Do the Putative Gate Keepers of Polyamine Synthesis Reside in Rat Brain?

    Directory of Open Access Journals (Sweden)

    Daniela Peters

    Full Text Available Polyamines are important regulators of basal cellular functions but also subserve highly specific tasks in the mammalian brain. With this respect, polyamines and the synthesizing and degrading enzymes are clearly differentially distributed in neurons versus glial cells and also in different brain areas. The synthesis of the diamine putrescine may be driven via two different pathways. In the "classical" pathway urea and carbon dioxide are removed from arginine by arginase and ornithine decarboxylase. The alternative pathway, first removing carbon dioxide by arginine decarboxlyase and then urea by agmatinase, may serve the same purpose. Furthermore, the intermediate product of the alternative pathway, agmatine, is an endogenous ligand for imidazoline receptors and may serve as a neurotransmitter. In order to evaluate and compare the expression patterns of the two gate keeper enzymes arginase and arginine decarboxylase, we generated polyclonal, monospecific antibodies against arginase-1 and arginine decarboxylase. Using these tools, we immunocytochemically screened the rat brain and compared the expression patterns of both enzymes in several brain areas on the regional, cellular and subcellular level. In contrast to other enzymes of the polyamine pathway, arginine decarboxylase and arginase are both constitutively and widely expressed in rat brain neurons. In cerebral cortex and hippocampus, principal neurons and putative interneurons were clearly labeled for both enzymes. Labeling, however, was strikingly different in these neurons with respect to the subcellular localization of the enzymes. While with antibodies against arginine decarboxylase the immunosignal was distributed throughout the cytoplasm, arginase-like immunoreactivity was preferentially localized to Golgi stacks. Given the apparent congruence of arginase and arginine decarboxylase distribution with respect to certain cell populations, it seems likely that the synthesis of agmatine

  15. Diverse Effects of L-arginine on Cardiac Function of Rats Subjected to Myocardial Ischemia and Reperfusion in vivo

    Institute of Scientific and Technical Information of China (English)

    Xiaoliang WANG; Feng LIANG; Xiangying JIAO; Lei LIU; Xiaojie BAI; Meixia LI; Jianmin ZHI; Huirong LIU

    2007-01-01

    In vivo administration of L-arginine at different time points during the course of myocardial ischemia and reperfusion (MI/R) has been shown to differentially regulate postischemic apoptosis.Cardiac function is one of the most important indexes used to judge the degree of myocardial injury.The present study attempted to determine whether in vivo administration of L-arginine at different stages of MI/R has a diverse influence on cardiac function of ischemic reperfused hearts and,if So,to investigate the mechanisms involved.Male adult rats were subjected to 30 min myocardial ischemia followed by 5 h reperfusion.An intravenous L-arginine bolus was given either 10 min before and 50 min after reperfusion (early treatment) or 3 h and 4 h after reperfusion (late treatment).Early treatment with L-arginine markedly increased the left ventricular systolic pressure (LVSP) and dP/dtmax,and decreased myocardial nitrotyrosine content.In strict contrast,late treatment with L-arginine resulted in a significant decrease in LVSP and dP/dtmx from 4 h to 5h after reperfusion,and increase in toxic peroxynitrite formation as measured by nitrotyrosine.These results suggest that the administration of L-arginine at different time points during the course of MI/R leads to diverse effects on cardiac dysfunction.Early supplementation decreased the nitrative stress and improved left ventricular function.However,late treatment with L-arginine increased the formation of peroxynitrite and aggravated cardiac functional injury.

  16. The crystal structure of the complex of PII and acetylglutamate kinase reveals how PII controls the storage of nitrogen as arginine

    OpenAIRE

    Llácer, José L.; Contreras, Asunción; Forchhammer, Karl; Marco-Marín, Clara; Gil-Ortiz, Fernando; Maldonado, Rafael; Fita, Ignacio; Rubio, Vicente

    2007-01-01

    Photosynthetic organisms can store nitrogen by synthesizing arginine, and, therefore, feedback inhibition of arginine synthesis must be relieved in these organisms when nitrogen is abundant. This relief is accomplished by the binding of the PII signal transduction protein to acetylglutamate kinase (NAGK), the controlling enzyme of arginine synthesis. Here, we describe the crystal structure of the complex between NAGK and PII of Synechococcus elongatus, at 2.75-Å resolution. We prove the physi...

  17. Site-directed mutagenesis and feedback-resistant N-acetyl-L-glutamate kinase (NAGK) increase Corynebacterium crenatum L-arginine production.

    Science.gov (United States)

    Xu, Meijuan; Rao, Zhiming; Dou, Wenfang; Yang, Juan; Jin, Jian; Xu, Zhenghong

    2012-07-01

    N-acetyl-L-glutamate kinase (EC 2.7.2.8) is first committed in the specific L-arginine pathway of Corynebacterium sp. A limited increase of L-arginine production for the argB overexpression in the engineering C. creantum SYPA-CCB strain indicated that L-arginine feedback inhibition plays an influence on the L-arginine production. In this study, we have performed site-directed mutagenesis of the key enzyme (NAGK) and the three mutations (E19R, H26E and H268D) exhibited the increase of I0.5R efficiently. Thereby, the multi-mutated NAGKM3 (including E19R/H26E/H268D) was generated and its I0.5R of L-arginine of the mutant was increased remarkably, whereas the NAGK enzyme activities did not declined. To get a feedback-resistant and robust L-arginine producer, the engineered strains SYPA-CCBM3 were constructed. Introducing the argBM3 gene enabled the NAGK enzyme activity insensitive to the intracellular arginine concentrations resulted in an enhanced arginine biosynthesis flux and decreased formation of by-products. The L-arginine synthesis was largely enhanced due to the overexpression of the argBM3, which is resistant to feedback resistant by L-arginine. Thus L-arginine production could reach 45.6 g/l, about 41.7% higher compared with the initial strain. This is an example of up-modulation of the flux through the L-arginine metabolic pathway by deregulating the key enzyme of the pathway. PMID:21901472

  18. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    , experience and consumption are all strategic design tools applied by planners and architects. Whereas urban design in former modernist planning served merely functional or political means, urban design has increasingly become an aesthetical mediator of ideologies embedded in the urban field of life forces...... capitalism not only changes urban life and its means of production, it specifically influences the way the city is designed and how it unfolds as events (Anderson & Harrison 2010) and affective, emotional production (Pile 2009). Through examples of urban design and events in the Carlsberg City in Copenhagen...... and The High Line in Chelsea, New York, the paper sets out to define and question these affective modes of production. Whether these productions are socio-material practices consisting of ludic designs (Stevens 2007), temporary architecture or art installations or evental practices consisting of...

  19. Improvement of L-arginine production by overexpression of a bifunctional ornithine acetyltransferase in Corynebacterium crenatum.

    Science.gov (United States)

    Dou, Wenfang; Xu, Meijuan; Cai, Dongmei; Zhang, Xiaomei; Rao, Zhiming; Xu, Zhenghong

    2011-10-01

    Ornithine acetyltransferase (EC 2.3.1.35; OATase) gene (argJ) from the L-arginine-producing mutant Corynebacterium crenatum SYPA5-5 was cloned, sequenced, and expressed in Escherichia coli BL21 (DE3). Analysis of the argJ sequence revealed that the argJ coded a polypeptide of 388 amino acids with a calculated molecular weight of 39.7 kDa. In this study, the function of the OATase (argJ) of C. crenatum SYPA5-5 has been identified as a conserved ATML sequence for the autolysis of the protein to α- and β-subunits. When the argJ regions corresponding to the α- and β-subunits were cloned and expressed separately in E. coli BL21, OATase activities were abolished. At the same time, a functional study revealed that OATase from C. crenatum SYPA5-5 was a bifunctional enzyme with the functions of acetylglutamate synthase (EC 2.3.1.1, NAGS) and acetylornithine deacetylase (EC 3.5.1.16, AOase) activities. In order to investigate the effects of the overexpression of the argJ gene on L: -arginine production, the argJ gene was inserted into pJCtac to yield the recombinant shuttle plasmid pJCtac-argJ and then transformed into C. crenatum SYPA5-5. The results showed that the engineered strains could not only express more OATase (90.9%) but also increase the production of L: -arginine significantly (16.8%). PMID:21785983

  20. Unveiling the Mechanism of Arginine Transport through AdiC with Molecular Dynamics Simulations: The Guiding Role of Aromatic Residues

    Science.gov (United States)

    Krammer, Eva-Maria; Ghaddar, Kassem; André, Bruno

    2016-01-01

    Commensal and pathogenic enteric bacteria have developed several systems to adapt to proton leakage into the cytoplasm resulting from extreme acidic conditions. One such system involves arginine uptake followed by export of the decarboxylated product agmatine, carried out by the arginine/agmatine antiporter (AdiC), which thus works as a virtual proton pump. Here, using classical and targeted molecular dynamics, we investigated at the atomic level the mechanism of arginine transport through AdiC of E. coli. Overall, our MD simulation data clearly demonstrate that global rearrangements of several transmembrane segments are necessary but not sufficient for achieving transitions between structural states along the arginine translocation pathway. In particular, local structural changes, namely rotameric conversions of two aromatic residues, are needed to regulate access to both the outward- and inward-facing states. Our simulations have also enabled identification of a few residues, overwhelmingly aromatic, which are essential to guiding arginine in the course of its translocation. Most of them belong to gating elements whose coordinated motions contribute to the alternating access mechanism. Their conservation in all known E. coli acid resistance antiporters suggests that the transport mechanisms of these systems share common features. Last but not least, knowledge of the functional properties of AdiC can advance our understanding of the members of the amino acid-carbocation-polyamine superfamily, notably in eukaryotic cells. PMID:27482712

  1. Study of coloration, microbe inhibition during the growth of L-arginine phosphate monohydrate single crystals

    Science.gov (United States)

    Li, Aidong; Xu, Chongquan; Li, Aibin; Ming, Naiben

    2000-12-01

    During the growth of L-arginine phosphate monohydrate (LAP) single crystals, the problems of coloration and microbial contamination of the solution were investigated. It was found that the solution coloration can be prevented by conducting crystal growth at temperatures lower than 40°C and by inhibiting microbial growth. Compared to the known microbe inhibitors H 2O 2 and n-hexane, liquid paraffin shows advantages of long durability and convenience of usage for the growth of high-quality LAP single crystals.

  2. The effects of 2-aminoethyl diphenylborinate on L-Arginine induced acute pancreatitis in the rats

    OpenAIRE

    Yildar, Murat; Basbug, Murat; Ozkan, Omer Faruk; Cavdar, Faruk; YAMAN, Ismail; Aksit, Hasan; Ozyigit, Musa Ozgür; ASLAN, Figen; Derici, Hayrullah

    2015-01-01

    Intraduction: The aim of the study is to investigate the protective effect of 2-aminoethyl diphenylborinate  on an acute pancreatitis model through an experimental study.Materials and Methods: 30 Spraque-Dawley male rats were randomly divided into three groups:  Sham ,  Pancreatitis and  Pancreatitis + 2-APB. Pancreatitis was induced by L-arginine administration. The therapeutic agent 2-APB was performed i.v. at a dose of 2 mg/kg 10 min before pancreatitis induction. From blood samples, super...

  3. Peptidyl arginine deiminase 4 participates in the pathogenesis of rheumatoid arthritis by influencing histone methylation

    Institute of Scientific and Technical Information of China (English)

    郭靖

    2013-01-01

    Objective To explore the probable function of peptidyl arginine deiminase 4 (PAD4) in rheumatoid arthritis (RA) .Methods Real-time quantitative polymerase chain reaction (PCR) was used to determine the expression of PAD4 mRNA in peripheral blood mononucleated cells (PBMCs) from 60 RA patients and 40 healthy individuals.Asymmetric di-methylation of histone H3R17,symmetric di-methylation and mono-methylation of H4R3were semi-quantified by Western blotting in 12 patients with osteoarthritis (OA) ,26 patients with RA and 10

  4. Insight on an arginine synthesis metabolon from the tetrameric structure of yeast acetylglutamate kinase

    OpenAIRE

    de Cima, Sergio; Gil-Ortiz, Fernando; Crabeel, Marjolaine; Fita, Ignacio; Rubio, Vicente

    2012-01-01

    N-acetyl-L-glutamate kinase (NAGK) catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS), which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yNAGK) has, in addition to the amino acid kinase (AAK) domain found in other NAGKs, a ∼150-residue C-terminal domain of unclear significance belonging to the DUF619 domain family. We deleted this domain,...

  5. Cloning and organization of seven arginine biosynthesis genes from Neisseria gonorrhoeae.

    OpenAIRE

    Picard, F J; Dillon, J R

    1989-01-01

    A genomic library for Neisseria gonorrhoeae, constructed in the lambda cloning vector EMBL4, was screened for clones carrying arginine biosynthesis genes by complementation of Escherichia coli mutants. Clones complementing defects in argA, argB, argE, argG, argIF, carA, and carB were isolated. An E. coli defective in the acetylornithine deacetylase gene (argE) was complemented by the ornithine acetyltransferase gene (argJ) from N. gonorrhoeae. This heterologous complementation is reported for...

  6. Delivery of siRNA Using Cationic Liposomes Incorporating Stearic Acid-modified Octa-Arginine.

    Science.gov (United States)

    Yang, Dongsheng; Li, Yuhuan; Qi, Yuhang; Chen, Yongzhen; Yang, Xuewei; Li, Yujing; Liu, Songcai; Lee, Robert J

    2016-07-01

    Cationic liposomes incorporating stearic acid-modified octa-arginine (StA-R8) were evaluated for survivin small interfering RNA (siRNA) delivery. StA-R8 was synthesized and incorporated into liposomes. The composition of liposomes was optimized. Physicochemical properties, cytotoxicity, cellular uptake and gene silencing activity of the liposomes complexed to survivin siRNA were investigated. The results showed that StA-R8-containing liposomes had reduced cytotoxicity and improved delivery efficiency of siRNA into cancer cells compared with StA-R8 by itself. PMID:27354583

  7. The story of invasive algae, arginine, and turtle tumors does not make sense

    Science.gov (United States)

    Work, Thierry M.; Ackermann, Mathias; Casey, James W.; Chaloupka, Milani; Herbst, Lawrence; Lynch, Jennifer M.; Stacy, Brian A.

    2014-01-01

    We are presenting a rebuttal letter to the following article that appeared recently on PeerJ: Van Houtan KS, Smith CM, Dailer ML, and Kawachi M. 2014. Eutrophication and the dietary promotion of sea turtle tumors. PeerJ 2:e602. This article is available at the following URL: https://peerj.com/articles/602/. We argue that the article lacks an inferential framework to answer the complex question regarding the drivers of the turtle tumor disease fibropapillomatosis in Hawaii. The article also contains procedural flaws and does not provide any compelling evidence of a link between algae, arginine, and turtle tumors.

  8. Different effects of L-arginine on morphine tolerance in sham and ovariectomized female mice

    Institute of Scientific and Technical Information of China (English)

    Reza KARAMI; Mahmoud HOSSEINI; Fatimeh KHODABANDEHLOO; Leila KHATAMI; Zahra TAIARANI

    2011-01-01

    Objective: The roles of gonadal hormones and nitric oxide (NO) on the analgesic effects of morphine,tolerance to morphine,and their interactions have been widely investigated.In the present study,the effect of L-arginine (an NO precursor) on morphine tolerance in sham and ovariectomized (OVX) female mice was investigated.Methods: Forty mice were divided into sham and OVX groups.On the first day,a hot plate test ((55±0.2) ℃; cut-off 30 s)was carried out as a base record 15 min before injection of morphine (10 mg/kg,subcutaneously (s.c.)) and was repeated every 15 min after injection.The sham group was then divided into two subgroups: sham-toleranceL-arginine (Sham-ToI-LA) and sham-tolerance-saline (Sham-ToI-Sal) which received either L-arginine 50 mg/kg (intraperitoneally (i.p.)) or saline 10 mi/kg (i.p.),respectively,three times in a day for three consecutive days.Morphine tolerance was induced in animals by injecting 30 mg/kg morphine (s.c.) three times/day for three days.This treatment was also used for OVX subgroups.On the fifth day,the hot plate test was repeated.The analgesic effect of morphine was calculated as the maximal percent effect (MPE).The results were compared using repeated measure analysis of variance (ANOVA).Results: There was no significant difference in MPE between the OVX and sham groups.The MPEs in both the Sham-ToI-Sal and OVX-ToI-Sal groups were lower than those in both the sham and OVX groups (P<0.01).The MPE in the OVX-ToI-Sal group was greater than that in the Sham-ToI-Sal group (P<0.01).The MPE in the Sham-ToI-LA group was higher than that in the Sham-ToI-Sal group (P<0.01).However,there was no significant difference between the Sham-ToI-LA and sham groups or between the OVX-ToI-LA and OVX-ToI-Sal groups.Conclusions: The results of the present study showed that repeated administration of morphine causes tolerance to the analgesic effect of morphine.L-Arginine could prevent tolerance to morphine but its effect was different in

  9. Radioimmunological determination of arginine vasopressin (AVP) after stimulation and suppression of secretion. Radioimmunologische Bestimmung von Arginin-Vasopressin (AVP) nach Stimulation und Suppression der Sekretion

    Energy Technology Data Exchange (ETDEWEB)

    Boeltz, E.

    1982-12-21

    As proof of the proper functioning of the hypothalamus-hypophyseal system the AVP secretion pattern which results from the analysis of plasma concentration at certain time intervals and under stimulation or suppression conditions can be used. 10 healthy control persons showed during an oral glucose intolerance test (=suppression) a significant decline in the AVP plasma concentration and after stimulation with apomorphine a healthy control person showed a large increase in AVP concentration in plasma. Because of the for the patient very stressful examination the physiological osmoregulation should first be checked during the infusion of a 2.5% NaCl solution with a minimal increase of the AVP plasma concentration. (TRV).

  10. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    Recently, in human geography there has been a considerable attention paid to retheorising maps; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic, performative, and participatory practice....... In particular, mapping environmental damage, endangered species, and human made disasters has become one of the focal point of affective knowledge production. These ‘more-than-humangeographies’ practices include notions of species, space and territory, and movement towards a new political ecology...

  11. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  12. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  13. Effect of feed restriction on metabolites in cerebrospinal fluid and plasma of dairy cows.

    Science.gov (United States)

    Laeger, T; Görs, S; Metges, C C; Kuhla, B

    2012-03-01

    plasma, whereas free fatty acids and volatile fatty acids were determined in plasma only. Although plasma arginine (132%), leucine (134%), lysine (117%), nonesterified fatty acids (224%), and cholesterol (112%) increased, tryptophan and carnosine decreased (-33% and -20%, respectively) in R animals as compared with AL animals. In CSF, concentrations of these metabolites were not affected after R feeding, suggesting that these identified plasma metabolites have only little potential to contribute to central feed intake regulatory signaling in cows. By contrast, in CSF, serine, threonine, and tyrosine decreased (-20, -24, and -31%, respectively) after R feeding. Therefore, these 3 AA are potential centrally acting anorexigenic signals in cows. PMID:22365204

  14. Intracerebroventricular injection of N omega-nitro-L-arginine in rats impairs learning in a 14-unit T-maze.

    Science.gov (United States)

    Ingram, D K; Spangler, E L; Kametani, H; Meyer, R C; London, E D

    1998-01-01

    We investigated whether intracerebroventricular (i.c.v.) infusion of the nitric oxide synthase inhibitor, Nomega-nitro-L-arginine (N-Arg), impairs learning in male Sprague-Dawley rats (2-3 months old) in a 14-unit T-maze. Rats were pretrained in one-way active avoidance to a criterion of 13/15 avoidances of foot shock in a straight runway. The next day, rats received i.c.v. injections of either artificial cerebrospinal fluid (aCSF) as controls or N-Arg (12 microg or 15 microg) 30 min before training in the 14-unit T-maze. The learning contingency was to negotiate each of 5 segments within 10 s to avoid footshock during 15 trials. Performance variables included errors (deviations from the correct pathway), runtime from start to goal, and shock frequency and duration. Compared to controls, the number of errors over the last 10 trials was higher in rats receiving 15 microg N-Arg and over the last 5 trials for those given 12 microg. Runtime, shock frequency and duration were increased in both N-Arg groups. The N-Arg-induced (15 microg i.c.v.) impairment could be attenuated when the nitric oxide donor, sodium nitroprusside (1 mg/kg), was administered intraperitoneally 1 min prior to maze learning. In a retention test, rats were treated with either aCSF or 15 microg N-Arg i.c.v. 30 min before being retested in the maze 7-10 d following acquisition training. Under these conditions, maze performance was not significantly affected. These results confirmed previous findings that inhibition of nitric oxide synthase impairs acquisition but not retention. Moreover, the N-Arg-induced learning impairment does not appear to be related to noncognitive aspects of performance. PMID:9489850

  15. Mechanistic and computational studies of the reductive half-reaction of tyrosine to phenylalanine active site variants of D-arginine dehydrogenase.

    Science.gov (United States)

    Gannavaram, Swathi; Sirin, Sarah; Sherman, Woody; Gadda, Giovanni

    2014-10-21

    The flavin-mediated enzymatic oxidation of a CN bond in amino acids can occur through hydride transfer, carbanion, or polar nucleophilic mechanisms. Previous results with D-arginine dehydrogenase from Pseudomonas aeruginosa (PaDADH) using multiple deuterium kinetic isotope effects (KIEs) and computational studies established preferred binding of the substrate protonated on the α-amino group, with cleavages of the NH and CH bonds occurring in asynchronous fashion, consistent with the three possible mechanisms. The hydroxyl groups of Y53 and Y249 are ≤4 Å from the imino and carboxylate groups of the reaction product iminoarginine, suggesting participation in binding and catalysis. In this study, we have investigated the reductive half-reactions of the Y53F and Y249F variants of PaDADH using substrate and solvent deuterium KIEs, solvent viscosity and pH effects, and quantum mechanical/molecular mechanical computational approaches to gain insights into the catalytic roles of the tyrosines and evaluate whether their mutations affect the transition state for substrate oxidation. Both Y53F and Y249F enzymes oxidized D-arginine with steady-state kinetic parameters similar to those of the wild-type enzyme. Rate constants for flavin reduction (k(red)) with D-leucine, a slow substrate amenable to rapid kinetics, were 3-fold smaller than the wild-type value with similar pKa values for an unprotonated group of ∼10.0. Similar pKa values were observed for (app)Kd in the variant and wild-type enzymes. However, cleavage of the substrate NH and CH bonds in the enzyme variants occurred in synchronous fashion, as suggested by multiple deuterium KIEs on k(red). These data can be reconciled with a hydride transfer mechanism, but not with carbanion and polar nucleophilic mechanisms. PMID:25243743

  16. Dietary L-arginine supplement alleviates hepatic heat stress and improves feed conversion ratio of Pekin ducks exposed to high environmental temperature.

    Science.gov (United States)

    Zhu, W; Jiang, W; Wu, L Y

    2014-12-01

    The current intensive indoor production system of commercial Pekin ducks never allows adequate water for swimming or wetting. Therefore, heat stress is a key factor affecting health and growth of ducks in the hot regions and season. Experiment 1 was conducted to study whether heat stress was deleterious to certain organs of ducks. Forty-one-day-old mixed-sex Pekin ducks were randomly allocated to four electrically heated battery brooders comprised of 10 ducks each. Ducks were suddenly exposed to 37 °C ambient temperature for 3 h and then slaughtered, in one brooder at 21 days and in another brooder at 49 days of age. The results showed that body weight and weight of immune organs, particularly liver markedly decreased in acute heat stress ducks compared with the control. Experiment 2 was carried out to investigate the influences of dietary L-arginine (Arg) supplement on weight and compositions of certain lymphoid organs, and growth performance in Pekin ducks, under daily cyclic hot temperature environment. A total of 151-day-old mixed-sex Pekin ducks were randomly divided into one negative control and two treatment groups, fed experimental diets supplemented with 0, 5, and 10 g L-Arginine (L-Arg)/kg to the basal diet respectively. Ducks were exposed to cyclic high temperature simulating natural summer season. The results showed that the addition of L-Arg improves feed conversion ratio (FCR) during a period of 7-week trial, as well as increases hepatic weight relative to body weight at 21 days, while decreases the hepatic water content at 49 days of age. This study indicated that the liver was more sensitive to acute heat stress, and the hepatic relative weight and chemical composition could be regulated by dietary L-Arg supplementation in Pekin ducks being reared at high ambient temperature. These beneficial effects of Arg on liver might be a cause of improved FCR. PMID:24773570

  17. Structural bases of feed-back control of arginine biosynthesis, revealed by the structures of two hexameric N-acetylglutamate kinases, from Thermotoga maritima and Pseudomonas aeruginosa.

    Science.gov (United States)

    Ramón-Maiques, Santiago; Fernández-Murga, María Leonor; Gil-Ortiz, Fernando; Vagin, Alexei; Fita, Ignacio; Rubio, Vicente

    2006-02-24

    N-Acetylglutamate kinase (NAGK) catalyses the second step in the route of arginine biosynthesis. In many organisms this enzyme is inhibited by the final product of the route, arginine, and thus plays a central regulatory role. In addition, in photosynthetic organisms NAGK is the target of the nitrogen-signalling protein PII. The 3-D structure of homodimeric, arginine-insensitive, Escherichia coli NAGK, clarified substrate binding and catalysis but shed no light on arginine inhibition of NAGK. We now shed light on arginine inhibition by determining the crystal structures, at 2.75 A and 2.95 A resolution, of arginine-complexed Thermotoga maritima and arginine-free Pseudomonas aeruginosa NAGKs, respectively. Both enzymes are highly similar ring-like hexamers having a central orifice of approximately 30 A diameter. They are formed by linking three E.coli NAGK-like homodimers through the interlacing of an N-terminal mobile kinked alpha-helix, which is absent from E.coli NAGK. Arginine is bound in each subunit of T.maritima NAGK, flanking the interdimeric junction, in a site formed between the N helix and the C lobe of the subunit. This site is also present, in variable conformations, in P.aeruginosa NAGK, but is missing from E.coli NAGK. Arginine, by gluing the C lobe of each subunit to the inter-dimeric junction, may stabilize an enlarged active centre conformation, hampering catalysis. Acetylglutamate counters arginine inhibition by promoting active centre closure. The hexameric architecture justifies the observed sigmoidal arginine inhibition kinetics with a high Hill coefficient (N approximately 4), and appears essential for arginine inhibition and for NAGK-PII complex formation, since this complex may involve binding of NAGK and PII with their 3-fold axes aligned. The NAGK structures allow identification of diagnostic sequence signatures for arginine inhibition. These signatures are found also in the homologous arginine-inhibited enzyme NAG synthase. The findings

  18. Backbone rigidity and static presentation of guanidinium groups increases cellular uptake of arginine-rich cell-penetrating peptides.

    Science.gov (United States)

    Lättig-Tünnemann, Gisela; Prinz, Manuel; Hoffmann, Daniel; Behlke, Joachim; Palm-Apergi, Caroline; Morano, Ingo; Herce, Henry D; Cardoso, M Cristina

    2011-01-01

    In addition to endocytosis-mediated cellular uptake, hydrophilic cell-penetrating peptides are able to traverse biological membranes in a non-endocytic mode termed transduction, resulting in immediate bioavailability. Here we analysed structural requirements for the non-endocytic uptake mode of arginine-rich cell-penetrating peptides, by a combination of live-cell microscopy, molecular dynamics simulations and analytical ultracentrifugation. We demonstrate that the transduction efficiency of arginine-rich peptides increases with higher peptide structural rigidity. Consequently, cyclic arginine-rich cell-penetrating peptides showed enhanced cellular uptake kinetics relative to their linear and more flexible counterpart. We propose that guanidinium groups are forced into maximally distant positions by cyclization. This orientation increases membrane contacts leading to enhanced cell penetration. PMID:21878907

  19. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy. PMID:23888587

  20. Plasma Science Committee (PLSC)

    International Nuclear Information System (INIS)

    The Plasma Science Committee (PLSC) is a standing committee under the auspices of the Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Applications of the National Academy of Sciences--National Research Council. Plasma sciences represent a broad and diverse field. The PLSC has accepted the responsibility of monitoring the continuing development and assessing the general health of the field as whole. Although select advisory bodies have been created to address specific issues that affect plasma science, such as the Fusion Policy Advisory Committee (FPAC), the PLSC provides a focus for the plasma science community that is unique and essential. The membership of the PLSC is drawn from research laboratories in universities, industry, and government. Areas of expertise on the committee include accelerators and beams, space physics, astrophysics, computational physics and applied mathematics, fusion plasmas, fundamental experiments and theory, radiation sources, low temperature plasmas, and plasma-surface interactions. The PLSC is well prepared to respond to requests for studies on specific issues. This report discusses ion of the PLSC work

  1. Proteolytic processing of Escherichia coli twin-arginine signal peptides by LepB.

    Science.gov (United States)

    Lüke, Iris; Handford, Jennifer I; Palmer, Tracy; Sargent, Frank

    2009-12-01

    The twin-arginine translocation (Tat) apparatus is a protein targeting system found in the cytoplasmic membranes of many prokaryotes. Substrate proteins of the Tat pathway are synthesised with signal peptides bearing SRRxFLK 'twin-arginine' amino acid motifs. All Tat signal peptides have a common tripartite structure comprising a polar N-terminal region, followed by a hydrophobic region of variable length and a polar C-terminal region. In Escherichia coli, Tat signal peptides are proteolytically cleaved after translocation. The signal peptide C-terminal regions contain conserved AxA motifs, which are possible recognition sequences for leader peptidase I (LepB). In this work, the role of LepB in Tat signal peptide processing was addressed directly. Deliberate repression of lepB expression prevented processing of all Tat substrates tested, including SufI, AmiC, and a TorA-23K reporter protein. In addition, electron microscopy revealed gross defects in cell architecture and membrane integrity following depletion of cellular LepB protein levels. PMID:19809807

  2. Fragment based discovery of Arginine isosteres through REPLACE: towards non-ATP competitive CDK inhibitors

    Science.gov (United States)

    Premnath, Padmavathy Nandha; Liu, Shu; Perkins, Tracy; Abbott, Jennifer; Anderson, Erin; McInnes, Campbell

    2013-01-01

    In order to develop non-ATP competitive CDK2/cyclin A inhibitors, the REPLACE strategy has been applied to generate fragment alternatives for the N-terminal tetrapeptide of the cyclin binding motif (HAKRRLIF) involved in substrate recruitment prior to phosphotransfer. The docking approach used for the prediction of small molecule mimics for peptide determinants was validated through reproduction of experimental binding modes of known inhibitors and provides useful information for evaluating binding to protein-protein interaction sites. Further to this, potential arginine isosteres predicted using the validated LigandFit docking method were ligated to the truncated C-terminal peptide, RLIF using solid phase synthesis and evaluated in a competitive binding assay. After testing, identified fragments were shown to represent not only appropriate mimics for a critical arginine residue but also to interact effectively with a minor hydrophobic pocket present in the binding groove. Further evaluation of binding modes was undertaken to optimize the potency of these compounds. Through further application of the REPLACE strategy in this study, peptide-small molecule hybrid CDK2 inhibitors were identified that are more drug-like and suitable for further optimization as anti-tumor therapeutics. PMID:24286762

  3. The formation of argpyrimidine, a methylglyoxal-arginine adduct, in the nucleus of neural cells

    International Nuclear Information System (INIS)

    Methylglyoxal (MG) is an endogenous metabolite in glycolysis and forms stable adducts primarily with arginine residues of intracellular proteins. The biological role of this modification in cell function is not known. In the present study, we found that a MG-detoxification enzyme glyoxalase I (GLO1) is mainly expressed in the ventricular zone (VZ) at embryonic day 16 which neural stem and progenitor cells localize. Moreover, immunohistochemical analysis revealed that argpyrimidine, a major MG-arginine adduct, is predominantly produced in cortical plate neurons not VZ during cerebral cortex development and is exclusively located in the nucleus. Immunoblotting experiment showed that the formation of argpyrimidine occurs on some nuclear proteins of cortical neurons. To our knowledge, this is first report of the argpyrimidine formation in the nucleus of neuron. These findings suggest that GLO1, which is dominantly expressed in the embryonic VZ, reduces the intracellular level of MG and suppresses the formation of argpyrimidine in neural stem and progenitor cells. Argpyrimidine may contribute to the neural differentiation and/or the maintenance of the differentiated state via the modification of nuclear proteins.

  4. Role of type II protein arginine methyltransferase 5 in the regulation of Circadian Per1 gene.

    Directory of Open Access Journals (Sweden)

    Jungtae Na

    Full Text Available Circadian clocks are the endogenous oscillators that regulate rhythmic physiological and behavioral changes to correspond to daily light-dark cycles. Molecular dissections have revealed that transcriptional feedback loops of the circadian clock genes drive the molecular oscillation, in which PER/CRY complexes inhibit the transcriptional activity of the CLOCK/BMAL1 heterodimer to constitute a negative feedback loop. In this study, we identified the type II protein arginine methyltransferase 5 (PRMT5 as an interacting molecule of CRY1. Although the Prmt5 gene was constitutively expressed, increased interaction of PRMT5 with CRY1 was observed when the Per1 gene was repressed both in synchronized mouse liver and NIH3T3 cells. Moreover, rhythmic recruitment of PRMT5 and CRY1 to the Per1 gene promoter was found to be associated with an increased level of histone H4R3 dimethylation and Per1 gene repression. Consistently, decreased histone H4R3 dimethylation and altered rhythmic Per1 gene expression were observed in Prmt5-depleted cells. Taken together, these findings provide an insight into the link between histone arginine methylation by PRMT5 and transcriptional regulation of the circadian Per1 gene.

  5. Dietary l-Arginine Supplementation Protects Weanling Pigs from Deoxynivalenol-Induced Toxicity

    Directory of Open Access Journals (Sweden)

    Li Wu

    2015-04-01

    Full Text Available This study was conducted to determine the positive effects of dietary supplementation with l-arginine (Arg on piglets fed a deoxynivalenol (DON-contaminated diet. A total of eighteen, 28-day-old healthy weanling pigs were randomly assigned into one of three groups: uncontaminated basal diet (control group, 6 mg/kg DON-contaminated diet (DON group and 6 mg/kg DON + 1% l-arginine (DON + ARG group. After 21 days of Arg supplementation, piglets in the DON and DON + ARG groups were challenged by feeding 6 mg/kg DON-contaminated diet for seven days. The results showed that DON resulted in damage to piglets. However, clinical parameters, including jejunal morphology, amino acid concentrations in the serum, jejunum and ileum, were improved by Arg (p < 0.05. Furthermore, the mRNA levels for sodium-glucose transporter-1 (SGLT-1, glucose transporter type-2 (GLUT-2 and y+l-type amino acid transporter-1 (y+LAT-1 were downregulated in the DON group, but the values were increased in the DON + ARG group (p < 0.05. Collectively, these results indicate that dietary supplementation with Arg exerts a protective role in pigs fed DON-contaminated diets.

  6. Dietary L-arginine supplementation protects weanling pigs from deoxynivalenol-induced toxicity.

    Science.gov (United States)

    Wu, Li; Liao, Peng; He, Liuqin; Feng, Zemeng; Ren, Wenkai; Yin, Jie; Duan, Jielin; Li, Tiejun; Yin, Yulong

    2015-04-01

    This study was conducted to determine the positive effects of dietary supplementation with L-arginine (Arg) on piglets fed a deoxynivalenol (DON)-contaminated diet. A total of eighteen, 28-day-old healthy weanling pigs were randomly assigned into one of three groups: uncontaminated basal diet (control group), 6 mg/kg DON-contaminated diet (DON group) and 6 mg/kg DON + 1% L-arginine (DON + ARG group). After 21 days of Arg supplementation, piglets in the DON and DON + ARG groups were challenged by feeding 6 mg/kg DON-contaminated diet for seven days. The results showed that DON resulted in damage to piglets. However, clinical parameters, including jejunal morphology, amino acid concentrations in the serum, jejunum and ileum, were improved by Arg (p SGLT-1), glucose transporter type-2 (GLUT-2) and y(+)L-type amino acid transporter-1 (y(+)LAT-1) were downregulated in the DON group, but the values were increased in the DON + ARG group (p < 0.05). Collectively, these results indicate that dietary supplementation with Arg exerts a protective role in pigs fed DON-contaminated diets. PMID:25884909

  7. Improved Activity Assay Method for Arginine Kinase Based on a Ternary Heteropolyacid System

    Institute of Scientific and Technical Information of China (English)

    陈宝玉; 郭勤; 郭智; 王希成

    2003-01-01

    This paper presents a new system for the activity assay of arginine kinase (AK), based on the spectrophotometric determination of an ascorbic acid-reduced blue ternary heteropolyacid composed of bismuth, molybdate and the released phosphate from N-phospho-L-arginine (PArg) formed in the forward catalysis reaction.The assay conditions, including the formulation of the phosphate determination reagent (PDR), the assay timing, and the linear activity range of the enzyme concentration, have been tested and optimized.For these conditions, the ternary heteropolyacid color is completely developed within 1 min and is stable for at least 15 min, with an absorbance maximum at 700 nm and a molar extinction coefficient of 15.97 (mmol/L)-1 · cm-1 for the phosphate.Standard curves for phosphate show a good linearity of 0.999.Compared with previous activity assay methods for AK, this system exhibits superior sensitivity, reproducibility, and adaptability to various conditions in enzymological studies.This method also reduces the assay time and avoids the use of some expensive instruments and reagents.

  8. Plasma device

    International Nuclear Information System (INIS)

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  9. Molecular basis for modulated regulation of gene expression in the arginine regulon of Escherichia coli K-12.

    OpenAIRE

    Cunin, R; T. Eckhardt; Piette, J.; Boyen, A; Piérard, A; Glansdorff, N

    1983-01-01

    We compare the nucleotide sequences of the regulatory regions of five genes or groups of genes of the arginine regulon of Escherichia coli K-12: argF, argI, argR, the bipolar argECBH operon and the carAB operon. All these regions harbour one or two copies of a conserved 18 bp sequence which appears to constitute the basic arginine operator sequence (ARG box). We discuss the influence of ARG box copy number, degree of dyad symmetry, base composition, and position relative to the cognate promot...

  10. Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction.

    Science.gov (United States)

    Ranjbar, Kamal; Rahmani-Nia, Farhad; Shahabpour, Elham

    2016-09-01

    Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats. PMID:27121159

  11. Molecular characterization of the argJ mutation in Neisseria gonorrhoeae strains with requirements for arginine, hypoxanthine, and uracil.

    OpenAIRE

    Martin, P R; Mulks, M H

    1992-01-01

    Arginine auxotrophs are commonly encountered among clinical isolates of Neisseria gonorrhoeae. Arginine auxotrophs which also require hypoxanthine and uracil (AHU strains) compose a unique set of strains that are highly homogeneous and are believed to be clonally derived. The Arg- phenotype of these strains is due to a lesion in the argJ gene encoding ornithine acetyltransferase. We have cloned the mutant argJ gene from an AHU strain and compared the sequence of this gene to the wild-type arg...

  12. Effects of methionine and arginine dietary levels on the immunity of broiler chickens submitted to immunological stimuli

    OpenAIRE

    LL Rubin; CW Canal; ALM Ribeiro; Kessler, A.; I. Silva; L Trevizan; Viola, T; M. Raber; TA Gonçalves; R Krás

    2007-01-01

    The present study aimed at assessing the effects of methionine and arginine on the immune response of broiler chickens submitted to immunological stimuli. Three methionine concentrations (0.31, 0.51, and 0.66% from 1 to 21 days of age; 0.29, 0.49, and 0.64% from 22 to 42 days of age) and 2 arginine concentrations (1.33 and 1.83%; 1.14 and 1.64% for the same life periods) were tested. Birds were divided into two groups for immunological stimuli (3x2x2 arrangement). Vaccines against Marek's dis...

  13. Actions of arginine polyamine on voltage and ligand-activated whole cell currents recorded from cultured neurones.

    OpenAIRE

    Scott, R. H.; Sweeney, M. I.; Kobrinsky, E. M.; Pearson, H. A.; Timms, G. H.; Pullar, I A; Wedley, S.; Dolphin, A. C.

    1992-01-01

    1. Toxins from invertebrates have proved useful tools for investigation of the properties of ion channels. In this study we describe the actions of arginine polyamine which is believed to be a close analogue of FTX, a polyamine isolated from the American funnel web spider, Agelenopsis aperta. 2. Voltage-activated Ca2+ currents and Ca(2+)-dependent Cl- currents recorded from rat cultured dorsal root ganglion neurones were reversibly inhibited by arginine polyamine (AP; 0.001 to 100 microM). Lo...

  14. Arginine-esterase activity of kallikrein in the sera of whole-body irradiated rats and guinea-pigs

    International Nuclear Information System (INIS)

    In whole-body irradiated rats (800 R=LDsub(50/30)) and guinea pigs (300 R=LDsub(50/30)) changes were investigated in the arginine esterase activity of kallikrein in native serum as well as in serum exposed to contact with a clay suspension. From the values obtained the activity of prekallikrein was calculated. While in the rat serum significant changes in the arginine esterase activity of kallikrein were found, in the guinea pig serum the kallikrein activity did not change markedly. The activity of prekallikrein immediately after irradiation assumes a similar course in both types of laboratory animals while during later intervals a reverse pattern was observed. (author)

  15. Effect of insulin on glucose- and arginine-stimulated somatostatin secretion from the isolated perfused rat pancreas

    OpenAIRE

    Gerber, Pietro; Trimble, E. R.; Wollheim, Claes; Renold, A E

    1981-01-01

    The effects of exogenous insulin on somatostatin secretion from the isolated perfused rat pancreas have been investigated in the presence of 5.6 mM glucose and when somatostatin secretion was stimulated by either glucose (16.7 mM) or arginine (20 mM). Insulin (15 mU/ml) significantly and rapidly suppressed glucose- and arginine-stimulated somatostatin release. However, at 5.6 mM glucose and, in the absence of other stimulators of somatostatin release, insulin had no effect on the somatostatin...

  16. Effect of ionizing radiation on the free amino acid content of blood plasma of chick embryos

    International Nuclear Information System (INIS)

    As has been shown by thin-layer chromatography irradiation (1000 rad) of chick embryos decreases the free amino acid content of blood plasma. The quantity of lysine and histidine was only decreased 24 hours after exposure. The contents of lysine, histidine, arginine, glycine, glutamine, serine, aspartic and glutamic acids, threonine and alanine reduced 2, 3 and 10 days after irradiation. The amount of leucine, isoleucine, phenylalanine, methionine, valine and tyrosine remained invariable throughout the entire perjod of observation

  17. Time-dependent alterations in serum NO concentration after oral administration of L-arginine, L-NAME, and allopurinol in intestinal ischemia/reperfusion

    Directory of Open Access Journals (Sweden)

    Amalia E Yanni

    2008-05-01

    present study show that NO concentration is elevated in serum after intestinal I/R and the elevation sustained after administration of L-Arg but not after administration of L-NAME or Allo after 1 hr reperfusion. However, after 8 hrs of reperfusion NO concentration was increased in all groups studied, focusing attention on its possible important role in a complicated situation such as intestinal I/R that involves intestine and other organs. Serum catalase activity does not seem to be affected by per os supplementation of L-Arg or Allo in intestinal I/R.Keywords: intestine, ischemia-reperfusion, nitric oxide, L-Arginine, NG-nitro-L-arginine methyl ester, allopurinol

  18. Vitamin B-6 restriction tends to reduce the red blood cell glutathione synthesis rate without affecting red blood cell or plasma glutathione concentrations in healthy men and women123

    OpenAIRE

    Lamers, Yvonne; O'Rourke, Bruce; Gilbert, Lesa R; Keeling, Christine; Matthews, Dwight E.; Stacpoole, Peter W.; Gregory, Jesse F.

    2009-01-01

    Background: Glutathione plays various protective roles in the human body. Vitamin B-6 as pyridoxal-5′-phosphate (PLP) is required as the coenzyme in the formation of glutathione precursors. Despite this obligatory role of PLP, previous studies from this laboratory showed that vitamin B-6 deficiency caused elevated glutathione concentrations in rat liver and human plasma.

  19. Arginine Supplementation Recovered the IFN-γ-Mediated Decrease in Milk Protein and Fat Synthesis by Inhibiting the GCN2/eIF2α Pathway, Which Induces Autophagy in Primary Bovine Mammary Epithelial Cells

    Science.gov (United States)

    Xia, Xiaojing; Che, Yanyi; Gao, Yuanyuan; Zhao, Shuang; Ao, Changjin; Yang, Hongjian; Liu, Juxiong; Liu, Guowen; Han, Wenyu; Wang, Yuping; Lei, Liancheng

    2016-01-01

    During the lactation cycle of the bovine mammary gland, autophagy is induced in bovine mammary epithelial cells (BMECs) as a cellular homeostasis and survival mechanism. Interferon gamma (IFN-γ) is an important antiproliferative and apoptogenic factor that has been shown to induce autophagy in multiple cell lines in vitro. However, it remains unclear whether IFN-γ can induce autophagy and whether autophagy affects milk synthesis in BMECs. To understand whether IFN-γ affects milk synthesis, we isolated and purified primary BMECs and investigated the effect of IFN-γ on milk synthesis in primary BMECs in vitro. The results showed that IFN-γ significantly inhibits milk synthesis and that autophagy was clearly induced in primary BMECs in vitro within 24 h. Interestingly, autophagy was observed following IFN-γ treatment, and the inhibition of autophagy can improve milk protein and milk fat synthesis. Conversely, upregulation of autophagy decreased milk synthesis. Furthermore, mechanistic analysis confirmed that IFN-γ mediated autophagy by depleting arginine and inhibiting the general control nonderepressible-2 kinase (GCN2)/eukaryotic initiation factor 2α (eIF2α) signaling pathway in BMECs. Then, it was found that arginine supplementation could attenuate IFN-γ-induced autophagy and recover milk synthesis to some extent. These findings may not only provide a novel measure for preventing the IFN-γ-induced decrease in milk quality but also a useful therapeutic approach for IFN-γ-associated breast diseases in other animals and humans. PMID:27025389

  20. Plasma antennas

    CERN Document Server

    Anderson, Theodore

    2011-01-01

    The plasma antenna is an emerging technology that partially or fully utilizes ionized gas as the conducting medium instead of metal to create an antenna. The key advantages of plasma antennas are that they are highly reconfigurable and can be turned on and off. The disadvantage is that the plasma antennas require energy to be ionized. This unique resource provides you with a solid understanding of the efficient design and prototype development of plasma antennas, helping you to meet the challenge of reducing the power required to ionize the gas at various plasma densities. You also find thorou