WorldWideScience

Sample records for sodium-phosphate cotransporters napi-iia

  1. Autosomal recessive hypophosphataemic rickets with hypercalciuria is not caused by mutations in the type II renal sodium/phosphate cotransporter gene.

    NARCIS (Netherlands)

    Heuvel, L.P.W.J. van den; Koul, K. Op de; Knots, E.; Knoers, N.V.A.M.; Monnens, L.A.H.

    2001-01-01

    BACKGROUND: At present the genetic defect for autosomal recessive and autosomal dominant hypophosphataemic rickets with hypercalciuria (HHRH) is unknown. Type II sodium/phosphate cotransporter (NPT2) gene is a serious candidate for being the causative gene in either or both autosomal recessive and

  2. Functional interaction between CFTR and the sodium-phosphate co-transport type 2a in Xenopus laevis oocytes.

    Directory of Open Access Journals (Sweden)

    Naziha Bakouh

    Full Text Available A growing number of proteins, including ion transporters, have been shown to interact with Cystic Fibrosis Transmembrane conductance Regulator (CFTR. CFTR is an epithelial chloride channel that is involved in Cystic Fibrosis (CF when mutated; thus a better knowledge of its functional interactome may help to understand the pathophysiology of this complex disease. In the present study, we investigated if CFTR and the sodium-phosphate co-transporter type 2a (NPT2a functionally interact after heterologous expression of both proteins in Xenopus laevis oocytes.NPT2a was expressed alone or in combination with CFTR in X. laevis oocytes. Using the two-electrode voltage-clamp technique, the inorganic phosphate-induced current (IPi was measured and taken as an index of NPT2a activity. The maximal IPi for NPT2a substrates was reduced when CFTR was co-expressed with NPT2a, suggesting a decrease in its expression at the oolemna. This was consistent with Western blot analysis showing reduced NPT2a plasma membrane expression in oocytes co-expressing both proteins, whereas NPT2a protein level in total cell lysate was the same in NPT2a- and NPT2a+CFTR-oocytes. In NPT2a+CFTR- but not in NPT2a-oocytes, IPi and NPT2a surface expression were increased upon PKA stimulation, whereas stimulation of Exchange Protein directly Activated by cAMP (EPAC had no effect. When NPT2a-oocytes were injected with NEG2, a short amino-acid sequence from the CFTR regulatory domain that regulates PKA-dependent CFTR trafficking to the plasma membrane, IPi values and NPT2a membrane expression were diminished, and could be enhanced by PKA stimulation, thereby mimicking the effects of CFTR co-expression.We conclude that when both CFTR and NPT2a are expressed in X. laevis oocytes, CFTR confers to NPT2a a cAMPi-dependent trafficking to the membrane. This functional interaction raises the hypothesis that CFTR may play a role in phosphate homeostasis.

  3. Effects of 1alpha-hydroxycholecalciferol on growth performance, parameters of tibia and plasma, meat quality, and type IIb sodium phosphate cotransporter gene expression of one- to twenty-one-day-old broilers.

    Science.gov (United States)

    Han, J C; Yang, X D; Zhang, T; Li, H; Li, W L; Zhang, Z Y; Yao, J H

    2009-02-01

    This experiment was conducted to investigate the effects of 1alpha-hydroxycholecalciferol (1alpha-OH D3) on the growth performance, tibia and plasma parameters, nutrient utilization, meat quality of the breast and thigh, and type IIb sodium phosphate cotranspoter gene expression of broilers. A total of 96 males of 1-d-old Arbor Acres broilers were randomly assigned to 8 cages of 12 birds each. Two dietary treatments were applied to 4 cages each. Diet 1 was prepared as the basal diet (nonphytate phosphorus, 0.21%), whereas diet 2 was the basal diet supplemented with 5 microg/kg of 1alpha-OH D3. Results showed that supplementation of the basal diet with 1alpha-OH D3 increased growth performance, tibia ash and strength, plasma inorganic phosphate concentration, utilization of total phosphorus and nonphytate phosphorus, lightness and yellowness of the breast and thigh meat, and intestinal type IIb sodium phosphate cotranspoter mRNA expression, whereas it decreased the shear force and water-holding capacity of the thigh meat. These data suggest that the addition of 1alpha-OH D3 might improve growth performance, tibia development, and meat quality in 1- to 21-d-old broilers by increasing the absorption and retention of phosphorus.

  4. Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas.

    Science.gov (United States)

    Becknell, Brian; Smoyer, William E; O'Brien, Nicole F

    2014-11-01

    This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity. This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas. Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity. Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

  5. Purification of Sodium Phosphates as by Product of Rirang Ore Decomposition Process

    International Nuclear Information System (INIS)

    Sugeng-Walujo; Hafni-LN; Susilaningtyas; Mukhlis; Budi-Sarono; Widowati

    2004-01-01

    The aim of this experiment is to get purification condition of sodium phosphates from the filtration result of mixing mother liquor and filtrate of washing residue from Rirang monazite decomposition by alkaline. The method of purification which has been used is dissolved the precipitation of sodium phosphates into agitated water 5 minutes and solution settling for 12 hours until appear of sodium phosphate crystals. The variable of experiment included dissolution time and ratio of the amount precipitate sodium phosphate volume of water to solvent. Experimental data shown that the good temperature of dissolution is 70 o C with the ratio of precipitate sodium phosphate is 80 gram/ 40 ml to water. The recovery of sodium phosphate crystallisation is 87.4314 % with 54.0105 % pure of Na 3 PO 4 , U content is 0.0004%, NaOH content and other impurities is 45.9889%. (author)

  6. EFFECT OF SODIUM PHOSPHATES ON SELECTED FOOD GRADE BACTERIA

    Directory of Open Access Journals (Sweden)

    Stanislav Kráčmar

    2011-04-01

    Full Text Available The aim of this study was to examine the inhibitory effect in vitro of selected sodium phosphates (under the corporate names Hexa 68, Hexa 70, Trikrystal, FST, Pyro 52, KPS, Didi on selected gram-positive and gram-negative bacteria. Seven different concentrations of each phosphate were used. Sensitivity of the bacterial strains to phosphates was observed in broth supplemented with salts. In vitro was showed a negative effect of various phosphates on growth of selected gram-positive bacteria. Orthophosphates and diphosphates (pyrophosphates did not have significant inhibitory effect on tested bacteria at neutral pH. With the exception of phosphate Trikrystal has not been found in vitro significant inhibitory effects on gram-negative bacteria.doi:10.5219/141

  7. Sodium Phosphate Supplementation and Time Trial Performance in Female Cyclists

    Directory of Open Access Journals (Sweden)

    Christopher L. Buck

    2014-09-01

    Full Text Available This study investigated the effects of three doses of sodium phosphate (SP supplementation on cycling 500 kJ (119.5 Kcal time trial (TT performance in female cyclists. Thirteen cyclists participated in a randomised, Latin-square design study where they completed four separate trials after ingesting either a placebo, or one of three different doses (25, 50 or 75 mg·kg-1 fat free mass: FFM of trisodium phosphate dodecahydrate which was split into four equal doses a day for six days. On the day after the loading phase, the TT was performed on a cycle ergometer. Serum phosphate blood samples were taken at rest both before and after each loading protocol, while a ~21 day washout period separated each loading phase. No significant differences in TT performance were observed between any of the supplementation protocols (p = 0.73 with average completion times for the 25, 50 or 75 mg·kg-1 FFM being, 42:21 ± 07:53, 40:55 ± 07:33 and 40:38 ± 07:20 min respectively, and 40:39 ± 07:51 min for the placebo. Likewise, average and peak power output did not significantly differ between trials (p = 0.06 and p = 0.46, respectively. Consequently, 500 kJ cycling TT performance was not different in any of the supplementation protocols in female cyclists.

  8. Sodium phosphate as a solid catalyst for biodiesel preparation

    Directory of Open Access Journals (Sweden)

    S. T. Jiang

    2010-03-01

    Full Text Available Sodium phosphate (Na3PO4 was chosen as catalyst for biodiesel preparation from rapeseed oil. The effects of mass ratio of catalyst to oil, molar ratio of methanol to oil, reaction temperature and rotation speed on biodiesel yield were investigated. For a mass ratio of catalyst to oil of 3%, molar ratio of methanol to oil of 9:1, reaction temperature of 343K and rotation speed of 600rpm, the transesterification was nearly completed within 20 minutes. Na3PO4 has a similar activity to homogeneous catalysts. Na3PO4 could be used repeatedly for 8 runs without any activation treatment and no obvious activity loss was observed. The concentrations of catalyst in biodiesel ranged from 0.6 to 0.7 mg/g. Compared to Na3PO4, Na3PO4.10H2O was cheaper, but the final yield was 71.3%, much lower than that of Na3PO4 at 99.7%.

  9. Oral sodium phosphate solution: a review of its use as a colorectal cleanser.

    Science.gov (United States)

    Curran, Monique P; Plosker, Greg L

    2004-01-01

    Oral sodium phosphate solution (Fleet Phospho-soda, Casen-Fleet Fosfosoda is a low-volume, hyperosmotic agent used as part of a colorectal-cleansing preparation for surgery, x-ray or endoscopic examination. The efficacy and tolerability of oral sodium phosphate solution was generally similar to, or significantly better than, that of polyethylene glycol (PEG) or other colorectal cleansing regimens in patients preparing for colonoscopy, colorectal surgery or other colorectal-related procedures. Generally, oral sodium phosphate solution was significantly more acceptable to patients than PEG or other regimens. The use of this solution should be considered in most patients (with the exception of those with contraindications) requiring colorectal cleansing. PHARMACOLOGICAL PROPERTIES: After the first and second 45 mL dose of oral sodium phosphate solution, the mean time to onset of bowel activity was 1.7 and 0.7 hours and the mean duration of activity was 4.6 and 2.9 hours. Bowel activity ceased within 4 hours of administration of the second dose in 83% of patients. Elevations in serum phosphorus and falls in serum total and ionised calcium from baseline occurred during the 24 hours after administration of oral sodium phosphate solution in seven healthy volunteers. These changes were not associated with significant changes in clinical assessments. The decrease in serum potassium levels after administration of oral sodium phosphate solution was negatively correlated with baseline intracellular potassium levels. A regimen that administered the first dose of sodium phosphate on the previous evening and a second dose on the morning of the procedure (10-12 hours apart) was significantly more effective than PEG-based regimens for colorectal cleansing in preparation for colonoscopy, sigmoidoscopy or colorectal surgery. A regimen that administered both doses of oral sodium phosphate on the day prior to the procedure offered no colorectal cleansing advantage over PEG

  10. [Optimization of riboflavin sodium phosphate loading to calcium alginate floating microspheres by response surface methodology].

    Science.gov (United States)

    Zhang, An-yang; Fan, Tian-yuan

    2009-12-18

    To investigate the preparation, optimization and in vitro properties of riboflavin sodium phosphate floating microspheres. The floating microspheres composed of riboflavin sodium phosphate and calcium alginate were prepared using ion gelatin-oven drying method. The properties of the microspheres were investigated, including the buoyancy, release, appearance and entrapment efficiency. The formulation was optimized by response surface methodology (RSM). The optimized microspheres were round. The entrapment efficiency was 57.49%. All the microspheres could float on the artificial gastric juice over 8 hours. The release of the drug from the microspheres complied with Fick's diffusion.

  11. Simultaneous Determination of Ciprofloxacin Hydrochloride and Dexamethasone Sodium Phosphate in Eye Drops by HPLC

    Directory of Open Access Journals (Sweden)

    Prakash Katakam

    2012-01-01

    Full Text Available A liquid chromatographic method was developed and validated for the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations. Optimum separation was achieved in less than 5 min using a C18 column (250 mmx4.6 mm i.d, 5μ particle size by isocratic elution. The mobile phase consisting of a mixture of mixed phosphate buffer (pH 4 and acetonitrile (65:35, v/v was used. Column effluents were monitored at 254 nm at a flow rate of 1ml/min. Retention times of ciprofloxacin hydrochloride and dexamethasone sodium phosphate were 2.0 and 3.16 min respectively. The linearity of ciprofloxacin hydrochloride and dexamethasone sodium phosphate was in the range of 3-18 μg/ml and 1-6 μg/ml respectively. Developed method was economical in terms of the time taken and amount of solvent consumed for each analysis. The method was validated and successfully applied to the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations.

  12. Hideout and hideout return of tri-sodium phosphate in PWR steam generators

    International Nuclear Information System (INIS)

    Feron, D.; You, D.; Turluer, G.

    2002-01-01

    Tri-sodium phosphate is used as a chemical conditioner of several sub-systems in secondary circuits of PWR. As confirmed by the international experience feedback of the secondary water chemistry, it can appear as a pollutant of the secondary water circuits, whereby it can concentrate in some areas of restricted flow or deposits in the steam generators. The issues raised by those occurrences prompted the safety French authorities (IPSN) to develop a model boiler investigation programme to assess the respective sodium/phosphate behaviour as a result of hideout and hideout return processes. Hideout and hideout return experiments have been performed with three model boilers in order to investigate the behaviour of tri-sodium phosphate pollution with three different configurations: only tube-tube support plate crevices, only sludge at the bottom of the tubes, or with only ''free'' tube surfaces. Obtained results, with discontinuous pollutions at some mg.kg -1 , can be summarised as follow: low hideout on the free surface of the tubes (less than 10%), hideout is more important when tube-tube support plate crevices are present (10 to 30%), maximum hideout is obtained when there is some sludge at the bottom of the tubes (30 to 90%), Hideout return data are always very low compared to the hideout quantities, due to the formation of solid compound with alumina and silica. (authors)

  13. Efficacy and tolerance of sodium phosphates oral solution after diet liberalization.

    Science.gov (United States)

    Scott, Sherrie R; Raymond, Patricia L; Thompson, William O; Galt, Deborah J B

    2005-01-01

    Bowel cleansing regimens commonly require adherence to liquid diets for 24 to 48 hours before examination, which often leads to poor compliance, reduced cleansing, and ultimately inadequate examinations. The authors investigated the efficacy and tolerability of diet liberalization before bowel cleansing with sodium phosphates oral solution. Two hundred patients were randomized into two treatment groups. One group received the standard light breakfast followed by clear liquids the day before colonoscopy; the second had a normal breakfast followed by a low-residue lunch the day before colonoscopy. Both groups had the same bowel preparation with sodium phosphates oral solution (2 x 45-mL, 7 p.m./6 a.m.). There was no difference in clinical efficacy between the two diet regimens (excellent/good in 93% standard, 95% low-residue). Fewer patients receiving the low-residue diet reported hunger, and more patients receiving the low-residue regimen reported energy to perform usual activities. This study supports offering patients a regular breakfast and a low-residue lunch before bowel cleansing with sodium phosphates oral solution.

  14. Hideout and hideout return of tri-sodium phosphate in PWR steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Feron, D.; You, D. [CEA/DEN - Laboratoire d' Etude de la Corrosion Aqueuse, Saclay (France); Turluer, G. [CEA/IPSN-Service d' Analyse des Materiels et des Structures, Fontenay-aux-Roses (France)

    2002-07-01

    Tri-sodium phosphate is used as a chemical conditioner of several sub-systems in secondary circuits of PWR. As confirmed by the international experience feedback of the secondary water chemistry, it can appear as a pollutant of the secondary water circuits, whereby it can concentrate in some areas of restricted flow or deposits in the steam generators. The issues raised by those occurrences prompted the safety French authorities (IPSN) to develop a model boiler investigation programme to assess the respective sodium/phosphate behaviour as a result of hideout and hideout return processes. Hideout and hideout return experiments have been performed with three model boilers in order to investigate the behaviour of tri-sodium phosphate pollution with three different configurations: only tube-tube support plate crevices, only sludge at the bottom of the tubes, or with only ''free'' tube surfaces. Obtained results, with discontinuous pollutions at some mg.kg{sup -1}, can be summarised as follow: low hideout on the free surface of the tubes (less than 10%), hideout is more important when tube-tube support plate crevices are present (10 to 30%), maximum hideout is obtained when there is some sludge at the bottom of the tubes (30 to 90%), Hideout return data are always very low compared to the hideout quantities, due to the formation of solid compound with alumina and silica. (authors)

  15. EFFECTS OF SODIUM PHOSPHATE LOADING ON AEROBIC POWER AND CAPACITY IN OFF ROAD CYCLISTS

    Directory of Open Access Journals (Sweden)

    Scott Woska

    2009-12-01

    Full Text Available The main aim of this paper was to evaluate the effects of short- term (6 days phosphate loading, as well as prolonged (21 days intake of sodium phosphate on aerobic capacity in off-road cyclists. Nineteen well-trained cyclists were randomly divided into a supplemental (S and control group (C. Group S was supplemented for 6 days with tri-sodium phosphate, in a dose of 50 mg·kg-1 of FFM/d, while a placebo was provided for the C group. Additionally, group S was further subjected to a 3-week supplementation of 25 mg·kg-1 FFM/d, while group C received 2g of glucose. The results indicate a significant (p < 0.05 increase in VO2max, VEmax, and O2/HR, due to sodium phosphate intake over 6 days. Also a significant (p < 0.05 decrease in HRrest and HRmax occurred. The supplementation procedure caused a significant increase (p < 0.05 in Pmax and a shift of VAT towards higher loads. There were no significant changes in the concentration of 2,3-DPG, acid-base balance and lactate concentration, due to phosphate salt intake

  16. Sodium Phosphate

    Science.gov (United States)

    ... through such as water, flavored water, lemonade without pulp, apple juice, and ginger ale. Do not drink ... a heart attack, chest pain, seizures, inflammatory bowel disease (IBD; a group of conditions in which all ...

  17. Treatment of cows with parturient paresis using intravenous calcium and oral sodium phosphate.

    Science.gov (United States)

    Braun, U; Grob, D; Hässig, M

    2016-09-01

    The goal of this study was to investigate whether intravenous infusion of 1000 ml 40% calcium borogluconate combined with the oral adminstration of 500 g sodium phosphate leads to a better cure rate and longer-lasting normocalcaemia and normophosphataemia than standard intravenous treatment with 500 ml calcium borogluconate in cows with parturient paresis. Forty recumbent cows with hypocalcaemia and hypophosphataemia were alternately allocated to group A or B. Cows of both groups were treated intravenously with 500 ml 40% calcium borogluconate, and cows of group B additionally received another 500 ml calcium borogluconate via slow intravenous infusion and 500 g sodium phosphate administered via an orogastric tube. Thirty-two cows stood within 8 hours after the start of treatment and 8 did not; of the 32 cows that stood, 18 belonged to group A and 14 to group B (90% of group A vs. 70% of group B; P = 0.23). Seven cows relapsed; of these and the 8 that did not respond to initial treatment, 10 stood after two standard intravenous treatments. Downer cow syndrome occurred in 5 cows, 3 of which recovered after aggressive therapy. The overall cure rate did not differ significantly between groups A and B. Twelve (60%) cows of group A and 14 (70%) cows of group B were cured after a single treatment and of the remaining 14, 11 were cured after two or more treatments. Two downer cows were euthanized and one other died of heart failure during treatment. Serum calcium concentrations during the first eight hours after the start of treatment were significantly higher in group B than in group A, and oral sodium phosphate caused a significant and lasting increase in inorganic phosphate. More cows of group B than group A were cured after a single treatment (P > 0.05). These findings, although not statistically significant, are promising and should be verified using a larger number of cows.

  18. Simultaneous Determination of Ciprofloxacin Hydrochloride and Dexamethasone Sodium Phosphate in Eye Drops by HPLC

    OpenAIRE

    Katakam, Prakash; Sireesha, Karanam R.

    2012-01-01

    A liquid chromatographic method was developed and validated for the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations. Optimum separation was achieved in less than 5 min using a C18 column (250 mmx4.6 mm i.d, 5μ particle size) by isocratic elution. The mobile phase consisting of a mixture of mixed phosphate buffer (pH 4) and acetonitrile (65:35, v/v) was used. Column effluents were monitored at 254 nm at a flow...

  19. Compatibility and stability of aloxi (palonosetron hydrochloride) admixed with dexamethasone sodium phosphate.

    Science.gov (United States)

    Trissel, Lawrence A; Zhang, Yanping

    2004-01-01

    The purpose of this study was to evaluate the physical and chemical stability of palonosetron hydrochloride 0.25 mg admixed with dexamethasone (as sodium phophate) 10 mg or 20 mg in 5% dextrose injection or 0.9% sodium chloride injection in polyvinylchloride minibags, and also admixed with dexamethasone (as sodium phosphate) 3.3 mg in 5% dextrose injection or 0.9% sodium chloride injection in polypropylene syringes, at 4 deg C stored in the dark for 14 days, and at 23 deg C exposed to normal laboratory fluorescent light over 48 hours. Test samples of palonosetron hydrochloride 5 micrograms/mL with dexamethasone (as sodium phosphate) 0.2 mg/mL and also 0.4 mg/mL were prepared in polyvinylchloride minibags of each infusion solution. Additionally, palonosetron hydrochloride 25 micrograms/mL with dexamethasone (as sodium phosphate) 0.33 mg/mL in each infusion solution were prepared as 10 mL of test solution in 20-mL polypropylene syringes. Evaluations for physical and chemical stability were performed on samples taken initially and after 1, 3, 7 and 14 days of storage at 4 deg C and after 1, 4, 24 and 48 hours at 23 deg C. Physical stability was assessed using visual observation in normal room light and using a high-intensity monodirectional light beam. In addition, turbidity and particle content were measured electronically. Chemical stability of the drug was evaluated by using a stability-indicating high-performance liquid chromatographic analytical technique. All samples were physically compatible throughout the study. The solutions remained clear and showed little or no change in particulate burden and haze level. Additionally, little or no loss of palonosetron hydrochloride and dexamethasone occurred in any of the samples at either temperature throughout the entire study period. Admixtures of palonosetron hydrochloride with dexamethasone sodium phosphate in 5% dextrose injection or in 0.9% sodium chloride injection packaged in polyvinylchloride minibags or in

  20. Spectral-luminescence properties of trivalent titanium in aluminum-sodium phosphate glass

    International Nuclear Information System (INIS)

    Sukhanov, S.B.; Batyaev, I.M.

    1992-01-01

    Since development of the first crystal laser, Al 2 O 3 crystals remain the most widely used in quantum electronics. In the present work, the aluminum-sodium phosphate glass, Al 2 O 3 -Na 2 O 3 -P 2 O 5 , was studied with different proportions of components. A luminescence medium is obtained based on phosphate glass doped by Ti 3+ ions with intense emission in the 700-900-nm spectral range. This glass is a promising lasing medium for tunable solid-state lasers. 12 refs., 2 figs

  1. Compatibility and Stability of Rolapitant Injectable Emulsion Admixed with Dexamethasone Sodium Phosphate.

    Science.gov (United States)

    Wu, George; Yeung, Stanley; Chen, Frank

    2017-01-01

    Neurokinin-1 receptor antagonist, 5-hydroxytryptamine-3 receptor antagonist, and dexamethasone combination therapy is the standard of care for the prevention of chemotherapy-induced nausea and vomiting. Herein, we describe the physical and chemical stability of an injectable emulsion of the Neurokinin-1 receptor antagonist rolapitant 185 mg in 92.5 mL (free base, 166.5 mg in 92.5 mL) admixed with either 2.5 mL of dexamethasone sodium phosphate (10 mg) or 5 mL of dexamethasone sodium phosphate (20 mg). Admixtures were prepared and stored in two types of container closures (glass and Crystal Zenith plastic bottles) and four types of intravenous administration tubing sets (or intravenous tubing sets). The assessment of the physical and chemical stability was conducted on admixtures packaged in bottled samples stored at room temperature (20°C to 25°C under fluorescent light) and evaluated at 0, 1, and 6 hours. For admixtures in intravenous tubing sets, the assessment of physicochemical stability was performed after 0 and 7 hours of storage at 20°C to 25°C, and then after 20 hours (total 27 hours) under refrigeration (2°C to 8°C) and protected from light. Physical stability was assessed by visually examining the bottle contents under normal room light and measuring turbidity and particulate matter. Chemical stability was assessed by measuring the pH of the admixture and determining drug concentrations through high-performance liquid chromatographic analysis. Results showed that all samples were physically compatible throughout the duration of the study. The admixtures stayed within narrow and acceptable ranges in pH, turbidity, and particulate matter. Admixtures of rolapitant and dexamethasone were chemically stable when stored in glass and Crystal Zenith bottles for at least 6 hours at room temperature, as well as in the four selected intravenous tubing sets for 7 hours at 20°C to 25°C and then for 20 (total 27 hours) hours at 2°C to 8°C. No loss of potency

  2. Copper(II) oxide solubility behavior in aqueous sodium phosphate solutions at elevated temperatures

    International Nuclear Information System (INIS)

    Ziemniak, S.E.; Jones, M.E.; Combs, K.E.S.

    1990-02-01

    A platinum-lined, flowing autoclave facility is used to investigate the solubility behavior of copper(II) oxide (CuO) in aqueous sodium phosphate solutions at temperatures between 292 and 535 K. Copper solubilities are observed to increase continuously with temperature and phosphate concentration. The measured solubility is examined via a Cu(II) ion hydrolysis/complexing model and thermodynamic functions for the hydrolysis/complexing reactions are obtained from a least- squares analysis of the data. Altogether, thermochemical properties are established for five anionic complexes: Cu(OH) 3 - , Cu(OH) 4 = , Cu(OH) 2 (HPO 4 ) = , Cu(OH) 3 (H 2 PO 4 ) = , and Cu(OH) 2 (PO 4 ) ≡ . Precise thermochemical parameters are also derived for the Cu(OH) + hydroxocomplex based on CuO solubility behavior previously observed in pure water (*) at elevated temperatures. The relative ease of Cu(II) ion hydrolysis is such that Cu(OH) 3 - species become the preferred hydroxocomplex for pH ≥ 9.4. 20 refs., 8 figs., 6 tabs

  3. Host sensitized near-infrared emission in Nd3+ doped different alkaline-sodium-phosphate phosphors

    Science.gov (United States)

    Balakrishna, A.; Swart, H. C.; Kroon, R. E.; Ntwaeaborwa, O. M.

    2018-04-01

    Near-infrared (NIR) emitting phosphors of different alkaline based sodium-phosphate (MNa[PO4], where M = Mg, Ca, Sr and Ba were prepared by a conventional solution combustion method with fixed doping concentration of Nd3+ (1.0 mol%). The phosphors were characterized by powder X-ray diffraction, field emission scanning electron microscope, Fourier transform infrared spectroscopy, UV-vis spectroscopy and fluorescent spectrophotometry. The optical properties including reflectance, excitation and emission were investigated. The excitation spectra of the phosphors were characterized by a broadband extending from 450 to 900 nm. Upon excitation with a wavelength of 580 nm, the phosphor emits intensely infrared region at 872 nm, 1060 nm and 1325 nm which correspond to the 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 transitions of Nd3+ ions and were found to vary for the different hosts. The strongest emission wavelength reaches 1060 nm. The most intense emission of Nd3+ was observed from Ca2+ incorporated host. The down conversion emissions of the material fall in the NIR region suggesting that the prepared phosphors have potential application in the development of photonic devices emitting in the NIR.

  4. Electron beam-induced radiation damage: the bubbling response in amorphous dried sodium phosphate buffer.

    Science.gov (United States)

    Massover, William H

    2010-06-01

    Irradiation of an amorphous layer of dried sodium phosphate buffer (pH = 7.0) by transmission electron microscopy (100-120 kV) causes rapid formation of numerous small spherical bubbles [10-100 A (= 1-10 nm)] containing an unknown gas. Bubbling is detected even with the first low-dose exposure. In a thin layer (ca. 100-150 A), bubbling typically goes through nucleation, growth, possible fusion, and end-state, after which further changes are not apparent; co-irradiated adjacent areas having a slightly smaller thickness never develop bubbles. In moderately thicker regions (ca. over 200 A), there is no end-state. Instead, a complex sequence of microstructural changes is elicited during continued intermittent high-dose irradiation: nucleation, growth, early simple fusions, a second round of extensive multiple fusions, general reduction of matrix thickness (producing flattening and expansion of larger bubbles, occasional bubble fission, and formation of very large irregularly-shaped bubbles by a third round of compound fusion events), and slow shrinkage of all bubbles. The ongoing lighter appearance of bubble lumens, maintenance of their rounded shape, and extensive changes in size and form indicate that gas content continues throughout their surprisingly long lifetime; the thin dense boundary layer surrounding all bubbles is proposed to be the main mechanism for their long lifetime.

  5. Nephrotic syndrome induced by dibasic sodium phosphate injections for twenty-eight days in rats.

    Science.gov (United States)

    Tsuchiya, Noriko; Torii, Mikinori; Narama, Isao; Matsui, Takane

    2009-04-01

    Sprague-Dawley rats received once daily tail-vein injections of 360 mM dibasic sodium phosphate solution at 8 mL/kg for fourteen or twenty-eight days. Clinical examination revealed persistent proteinuria from three days after the first dosing and thereafter severe proteinuria from eight days or later in the phosphate-treated groups. Proteinuria developed without remission even after fourteen-day withdrawal in the fourteen-day dosed group. Phosphate-treated animals developed lipemia, hypercholesterolemia, anemia, higher serum fibrinogen levels, and lower serum albumin/globulin ratios on day 29. Renal weight increased significantly compared with control animals, and the kidneys appeared pale and enlarged with a rough surface. Histopathologically, glomerular changes consisted of mineralization in whole glomeruli, glomerular capillary dilatation, partial adhesion of glomerular tufts to Bowman's capsule, and mesangiolysis. Ultrastructural lesions such as an increased number of microvilli, effacement of foot processes, and thickening of the glomerular basement membrane, and immunocytochemical changes in podocytes, mainly decreased podoplanin-positive cells and increased desmin expression, were also conspicuous in the phosphate-treated rats for twenty-eight days. Marked tubulointerstitial lesions were tubular regeneration and dilatation, protein casts, mineralization in the basement membrane, focal interstitial inflammation, and fibrosis in the cortex. These clinical and morphological changes were similar to features of human nephrotic syndrome.

  6. A randomized prospective triaI comparing oral sodium phosphate with magnesium citrate in preparing of patients for double contrast barium enema

    International Nuclear Information System (INIS)

    Lee, Eun Joo; Lee, Sung Woo; Lee, Hyeon Kyeong; Yang, Chang Hun; Kim, Soon; Oh, Yoen Hee; Kim, Seung Hyeon

    2004-01-01

    The purpose of this study was to compare two bowel preparation agents, sodium phosphate solution with magnesium citrate solution. A total of 94 subjects that underwent a double-contrast barium enema were included in this study. Bowel preparation before performing the barium study was done by using a sodium phosphate solution in 47 subjects and by using a magnesium citrate solution in the other 47 subjects. We evaluated the presence or absence of side effects when using these bowel preparation agents. Two radiologist who were blinded to the type of bowel preparation evaluated the quality of bowel preparation at the colonic segments (ascending, descending, and sigmoid colon) on the radiographs obtained by double-contrast barium enema, with regard to stool cleansing, water retention, barium coating and bubble formation. The side effects, such as abdominal clamping pain, nausea, hunger pain and chill occurred more frequently in the sodium phosphate group than in the magnesium citrate group (p< 0.001). Stool retention was more frequently found in the magnesium citrate group (p< 0.001). However, no statistical difference was noted on the status of water retention and barium coating between two groups. Gas bubble formation was more commonly seen in the sodium phosphate group (p< 0.001). The sodium phosphate solution appeared to be more effective in cleansing the right colon (p=0.001). Sodium phosphate solution appears to be more effective for colonic cleansing, with a lower incidence of side effects, than when using magnesium citrate solution

  7. Kidney injury after sodium phosphate solution beyond the acute renal failure.

    Science.gov (United States)

    Fernández-Juárez, Gema; Parejo, Leticia; Villacorta, Javier; Tato, Ana; Cazar, Ramiro; Guerrero, Carmen; Marin, Isabel Martinez; Ocaña, Javier; Mendez-Abreu, Angel; López, Katia; Gruss, Enrique; Gallego, Eduardo

    2016-01-01

    Screening colonoscopy with polipectomy reduces colonorectal cancer incidence and mortality. An adequate bowel cleansing is one of the keys to achieving best results with this technique. Oral sodium phosphate solution (OSP) had a widespread use in the 90s decade. Its efficacy was similar to polyethylene glycol (PEG) solution, but with less cost and convenient administration. Series of patients with acute renal failure due to OSP use have been reported. However, large cohorts of patients found no difference in the incidence of renal damage between these two solutions. From 2006 to 2009 we identified twelve cases of phosphate nephropathy after colonoscopy prepared with OSP. All patients were followed up to six months. All patients had received just a single dose. We analyzed 12 cases with phosphate nephropathy; three patients debuted with AKI and nine patients had chronic renal injury. Four cases were confirmed with renal biopsy. One patient with AKI needed hemodialysis at diagnosis without subsequent recovery. Two patients (both with chronic damage) fully recovered their previous renal function. The remaining patients (nine) had an average loss of estimated glomerular filtration rate of 24ml/min/1.73m(2). The use of OSP can lead to both acute and chronic renal damage. However, chronic injury was the most common pattern. Both forms of presentation imply a significant and irreversible loss of renal function. Further studies analyzing renal damage secondary to bowel cleaning should consider these two different patterns of injury. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  8. Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

    Directory of Open Access Journals (Sweden)

    Stef Robijn

    Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

  9. Effects of sodium phosphate and caffeine ingestion on repeated-sprint ability in male athletes.

    Science.gov (United States)

    Kopec, Benjamin J; Dawson, Brian T; Buck, Christopher; Wallman, Karen E

    2016-03-01

    To assess the effects of sodium phosphate (SP) and caffeine supplementation on repeated-sprint performance. Randomized, double-blind, Latin-square design. Eleven team-sport males participated in four trials: (1) SP (50mgkg(-1) of free fat-mass daily for six days) and caffeine (6mgkg(-1) ingested 1h before exercise); SP+C, (2) SP and placebo (for caffeine), (3) caffeine and placebo (for SP) and (4) placebo (for SP and caffeine). After loading, participants performed a simulated team-game circuit (STGC) consisting of 2×30min halves, with 6×20-m repeated-sprint sets performed at the start, half-time and end of the STGC. There were no interaction effects between trials for first-sprint (FS), best-sprint (BS) or total-sprint (TS) times (p>0.05). However, SP resulted in the fastest times for all sprints, as supported by moderate to large effect sizes (ES; d=0.51-0.83) and 'likely' to 'very likely' chances of benefit, compared with placebo. Compared with caffeine, SP resulted in 'possible' to 'likely' chances of benefit for FS, BS and TS for numerous sets and a 'possible' chance of benefit compared with SP+C for BS (set 2). Compared with placebo, SP+C resulted in moderate ES (d=0.50-0.62) and 'possible' to 'likely' benefit for numerous sprints, while caffeine resulted in a moderate ES (d=0.63; FS: set 3) and 'likely' chances of benefit for a number of sets. While not significant, ES and qualitative analysis results suggest that SP supplementation may improve repeated-sprint performance when compared with placebo. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. SIMULTANEOUS ESTIMATION OF MOXIFLOXACIN HYDROCHLORIDE AND DEXAMETHASONE SODIUM PHOSPHATE IN BULK AND IN OPHTHALMIC SOLUTION BY RP- HPLC

    OpenAIRE

    DHUMAL, D. M; SHIRKHEDKAR, A. A; NERKAR, P. P; SURANA, S. J

    2012-01-01

    A new simple, precise, accurate and selective RP-HPLC method has been developed and validated for simultaneous estimation of Moxifloxacin Hydrochloride (MOX) and Dexamethasone Sodium Phosphate (DSP) in Ophthalmic Solution. The method was carried out on a Qualisil RP C-8 (250 mm x 4.6 mm, 5 µm) column with a mobile phase consisting of Methanol: Water (75:25 v/v) pH adjusted to 3.0 with ortho-phosphoric acid of aqueous phase and flow rate of 1.0 mL min¹. Detection was carried out at 240 nm. The...

  11. Partitioning of L-methionine in aqueous two-phase systems containing poly(propylene glycol) and sodium phosphate salts

    Energy Technology Data Exchange (ETDEWEB)

    Salabat, Alireza, E-mail: a-salabat@araku.ac.ir [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of); Moghadam, Somayeh Tiani [Chemistry Department, Arak University, P.O. Box 38156-879, Arak (Iran, Islamic Republic of); Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj, Kurdistan 66135 (Iran, Islamic Republic of)

    2011-10-15

    Highlights: > Thermodynamics parameters for partitioning of L-methionine in ATPS. > Investigation of different effects on partition coefficient of the amino acid. > Propose the best condition for L-methionine partitioning. - Abstract: The partitioning behavior of L-methionine has been studied in aqueous two-phase systems of (poly(propylene glycol) + sodium phosphate salts + H{sub 2}O) at different temperatures. The salts used were sodium di-hydrogen phosphate (NaH{sub 2}PO{sub 4}), di-sodium hydrogen phosphate (Na{sub 2}HPO{sub 4}) and tri-sodium phosphate (Na{sub 3}PO{sub 4}). The effects of tie line length, salt type, and temperature on the partition coefficient of this amino acid have been studied. In addition, thermodynamic parameters ({Delta}H{sup o}, {Delta}S{sup o} and {Delta}G{sup o}) as a function of temperature were calculated. The results showed that increasing tie line length led to decreasing of the partition coefficient. We also showed that the partition coefficients of the amino acid in the systems containing Na{sub 3}PO{sub 4} are greater than the other two salts. Moreover, it is verified that increasing temperature led to decreasing the partition coefficient. The experimental partition coefficient data are correlated using a modified virial-type model.

  12. Partitioning of L-methionine in aqueous two-phase systems containing poly(propylene glycol) and sodium phosphate salts

    International Nuclear Information System (INIS)

    Salabat, Alireza; Sadeghi, Rahmat; Moghadam, Somayeh Tiani; Jamehbozorg, Bahman

    2011-01-01

    Highlights: → Thermodynamics parameters for partitioning of L-methionine in ATPS. → Investigation of different effects on partition coefficient of the amino acid. → Propose the best condition for L-methionine partitioning. - Abstract: The partitioning behavior of L-methionine has been studied in aqueous two-phase systems of (poly(propylene glycol) + sodium phosphate salts + H 2 O) at different temperatures. The salts used were sodium di-hydrogen phosphate (NaH 2 PO 4 ), di-sodium hydrogen phosphate (Na 2 HPO 4 ) and tri-sodium phosphate (Na 3 PO 4 ). The effects of tie line length, salt type, and temperature on the partition coefficient of this amino acid have been studied. In addition, thermodynamic parameters (ΔH o , ΔS o and ΔG o ) as a function of temperature were calculated. The results showed that increasing tie line length led to decreasing of the partition coefficient. We also showed that the partition coefficients of the amino acid in the systems containing Na 3 PO 4 are greater than the other two salts. Moreover, it is verified that increasing temperature led to decreasing the partition coefficient. The experimental partition coefficient data are correlated using a modified virial-type model.

  13. In vitro bioactivity of soda lime borate glasses with substituted SrO in sodium phosphate solution

    Directory of Open Access Journals (Sweden)

    Mohamed A. Marzouk

    2014-09-01

    Full Text Available Borate glasses with the basic composition 0.6B2O3·0.2Na2O·0.2CaO and SrO progressively substituting CaO were prepared and characterized for their bone-bonding ability. The obtained glasses were thermally treated and converted to their glass-ceramic derivatives. In this study, FTIR spectral analyses were done for the prepared glasses and glass-ceramics before and after immersion in a sodium phosphate solution for extended times. The appearance of two IR bands within the spectral range 550–680 cm-1 after immersion confirms the formation of hydroxyapatite. X-ray diffraction studies and scanning electron microscope analysis supported the obtained infrared spectroscopy results. The solubility test (measurements of the weight loss in aqueous sodium phosphate solution was conducted for measuring the dissolution of both glassy and crystalline derivatives to find out the role of SrO. The corrosion behaviour of the glasses and glass-ceramics indicate the increase of weight loss with the increase of SrO content. Different suggested proposals were introduced to explain this abnormal behaviour.

  14. Effect of poly(lactide-co-glycolide) molecular weight on the release of dexamethasone sodium phosphate from microparticles.

    Science.gov (United States)

    Jaraswekin, Saowanee; Prakongpan, Sompol; Bodmeier, Roland

    2007-03-01

    The objective of this study was to investigate the effect of poly(lactide-co-glycolide) (PLGA) molecular weight (Resomer RG 502H, RG 503H, and RG 504H) on the release behavior of dexamethasone sodium phosphate-loaded microparticles. The microparticles were prepared by three modifications of the solvent evaporation method (O/W-cosolvent, O/W-dispersion, and W/O/W-methods). The encapsulation efficiency of microparticles prepared by the cosolvent- and W/O/W-methods increased from approximately 50% to >90% upon addition of NaCl to the external aqueous phase, while the dispersion method resulted in lower encapsulation efficiencies. The release of dexamethasone sodium phosphate from PLGA microparticles (>50 microm) was biphasic. The initial burst release correlated well with the porosity of the microparticles, both of which increased with increasing polymer molecular weight (RG 504H > 503H > 502H). The burst was also dependent on the method of preparation and was in the order of dispersion method > WOW method > consolvent method. In contrast to the higher molecular weight PLGA microparticles, the release from RG 502H microparticles prepared by cosolvent method was not affected by volume of organic solvent (1.5-3.0 ml) and drug loading (4-13%). An initial burst of approximately 10% followed by a 5-week sustained release phase was obtained. Microparticles with a size <50 microm released in a triphasic manner; an initial burst was followed by a slow release phase and then by a second burst.

  15. Stability-Indicating HPLC Method for Simultaneous Determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in Ophthalmic Solution.

    Science.gov (United States)

    AlAani, Hashem; Alnukkary, Yasmin

    2016-03-01

    A simple stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of Chloramphenicol, Dexamethasone Sodium Phosphate and Tetrahydrozoline Hydrochloride in ophthalmic solution in the presence of 2-amino-1-(4-nitrophenyl)propane-1,3-diol, a degradation product of Chloramphenicol, and Dexamethasone, a degradation product of Dexamethasone Sodium Phosphate. Effective chromatographic separation was achieved using C18 column (250 mm, 4.6 mm i.d., 5 μm) with isocratic mobile phase consisting of acetonitrile - phosphate buffer (pH 4.0; 0.05 M) (30:70, v/v) at a flow rate of 1 mL/minute. The column temperature was maintained at 40°C and the detection wavelength was 230 nm. The proposed HPLC procedure was statistically validated according to the ICH guideline, and was proved to be stability-indicating by resolution of the APIs from their forced degradation products. The developed method is suitable for the routine analysis as well as stability studies.

  16. Stability of Diphenhydramine Hydrochloride, Lorazepam, and Dexamethasone Sodium Phosphate in 0.9% Sodium Chloride Stored in Polypropylene Syringes.

    Science.gov (United States)

    Anderson, Collin R; Halford, Zachery; MacKay, Mark

    2015-01-01

    Chemotherapy induced nausea and vomiting is problematic for many patients undergoing chemotherapy. Multiple-drug treatments have been developed to mitigate chemotherapy induced nausea and vomiting. A patient-controlled infusion of diphenhydramine hydrochloride, lorazepam, and dexamethasone sodium phosphate has been studied in patients who are refractory to first-line therapy. Unfortunately, the physical and chemical compatibility of this three-drug combination is not available in the published literature. Chemical compatibility was evaluated using high-performance liquid chromatography with ultraviolet detection. Visual observation was employed to detect change in color, clarity, or gas evolution. Turbidity and pH measurements were performed in conjunction with visual observation at hours 0, 24, and 48. Results showed that diphenhydramine hydrochloride 4 mg/mL, lorazepam 0.16 mg/mL, and dexamethasone sodium phosphate 0.27 mg/mL in 0.9% sodium chloride stored in polypropylene syringes were compatible, and components retained greater than 95% of their original concentration over 48 hours when stored at room temperature.

  17. Cotransporters as molecular water pumps

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; MacAulay, Nanna

    2002-01-01

    Molecular water pumps are membrane proteins of the cotransport type in which a flux of water is coupled to substrate fluxes by a mechanism within the protein. Free energy can be exchanged between the fluxes. Accordingly, the flux of water may be relatively independent of the external water chemical...

  18. Structural and luminescence studies of Ho{sup 3+}-doped zinc-aluminium-sodium-phosphate (ZANP) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y. C., E-mail: ratnakaramsvu@gmail.com [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India)

    2015-06-24

    Trivalent holmium doped zinc-aluminium-sodium-phosphate (ZANP) glasses were prepared by conventional melt-quenching technique and characterized for their structural and luminescence properties. The amorphous nature, elemental analysis and thermal stability of the glasses were studied by using X-ray diffraction, energy dispersive spectrum and differential scanning calorimetry analysis, respectively. The absorption and fluorescence spectra have been recorded at room temperature. Based on the absorption spectra, the Judd-Ofelt parameters and radiative parameters such as spontaneous transition probabilities (A{sub R}), branching ratios (β{sub R}), radiative lifetimes (τ{sub R}) were calculated and discussed. From the emission spectra emission peak positions (λ{sub P}), effective bandwidths (Δλ{sub eff}) and stimulated emission cross-sections (σ{sub P}) were calculated for the observed emission transitions,{sup 5}S{sub 2} ({sup 5}F{sub 4}→{sup 5}I{sub 8}) and {sup 5}F{sub 5}→{sup 5}I{sub 8} in all the glass samples. The stimulated emission cross-section is higher for ZANPHo10 glass matrix and so it may be useful for laser excitation.

  19. Comparative study of layer-by-layer deposition techniques for poly(sodium phosphate) and poly(allylamine hydrochloride).

    Science.gov (United States)

    Elosua, Cesar; Lopez-Torres, Diego; Hernaez, Miguel; Matias, Ignacio R; Arregui, Francisco J

    2013-12-20

    An inorganic short chain polymer, poly(sodium phosphate), PSP, together with poly(allylamine hydrochloride), PAH, is used to fabricate layer-by-layer (LbL) films. The thickness, roughness, contact angle, and optical transmittance of these films are studied depending on three parameters: the precursor solution concentrations (10-3 and 10-4 M), the number of bilayers deposited (20, 40, 60, 80, and 100 bilayers), and the specific technique used for the LbL fabrication (dipping or spraying). In most cases of this experimental study, the roughness of the nanofilms increases with the number of bilayers. This contradicts the basic observations made in standard LbL assemblies where the roughness decreases for thicker coatings. In fact, a wide range of thickness and roughness was achieved by means of adjusting the three parameters mentioned above. For instance, a roughness of 1.23 or 205 nm root mean square was measured for 100 bilayer coatings. Contact angles close to 0 were observed. Moreover, high optical transmittance is also reported, above 90%, for 80 bilayer films fabricated with the 10-4 M solutions. Therefore, these multilayer structures can be used to obtain transparent superhydrophilic surfaces.

  20. Thermal inactivation of Salmonella Enteritidis on chicken skin previously exposed to acidified Sodium chlorite or tri-sodium phosphate.

    Science.gov (United States)

    Karuppasamy, K; Yadav, Ajit S; Saxena, Gaurav K

    2015-12-01

    Thermal inactivation of normal and starved cells of Salmonella Enteritidis on chicken skin previously exposed to different concentrations of acidified sodium chlorite (ASC) or tri-sodium phosphate (TSP) was investigated. Inoculated skin was pretreated with different concentration of ASC or TSP, packaged in bags, and then immersed in a circulating water bath at 60 to 68 °C. The recovery medium was Hektoen enteric agar. D-values, determined by linear regression, for normal cells on chicken skin, were 2.79, 1.17 and 0.53 min whereas D-values for starved cells were 4.15, 1.83 and 0.66 at 60, 64 and 68 °C, respectively. z-values for normal cells were 3.54 and for starved cells were 2.29. Pretreatment of Salmonella Enteritidis cells with 0 to 200 ppm of ASC or 0 to 1.0 % TSP resulted in lower D-values at all temperatures. Sensory results indicated no significance differences for control and treatments. Thus, results of this study indicated that pretreatment of chicken skin with ASC or TSP increased sensitivity of Salmonella Enteritidis to heat without affecting organoleptic quality of chicken meat.

  1. Stability of i.v. admixture containing metoclopramide, diphenhydramine hydrochloride, and dexamethasone sodium phosphate in 0.9% sodium chloride injection.

    Science.gov (United States)

    Kintzel, Polly E; Zhao, Ting; Wen, Bo; Sun, Duxin

    2014-12-01

    The chemical stability of a sterile admixture containing metoclopramide 1.6 mg/mL, diphenhydramine hydrochloride 2 mg/mL, and dexamethasone sodium phosphate 0.16 mg/mL in 0.9% sodium chloride injection was evaluated. Triplicate samples were prepared and stored at room temperature without light protection for a total of 48 hours. Aliquots from each sample were tested for chemical stability immediately after preparation and at 1, 4, 8, 24, and 48 hours using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Metoclopramide, diphenhydramine hydrochloride, and dexamethasone sodium phosphate were selectively monitored using multiple-reaction monitoring. Samples were diluted differently for quantitation using three individual LC-MS/MS methods. To determine the drug concentration of the three compounds in the samples, three calibration curves were constructed by plotting the peak area or the peak area ratio versus the concentration of the calibration standards of each tested compound. Apixaban was used as an internal standard. Linearity of the calibration curve was evaluated by the correlation coefficient r(2). Constituents of the admixture of metoclopramide 1.6 mg/mL, diphenhydramine hydrochloride 2 mg/mL, and dexamethasone sodium phosphate 0.16 mg/mL in 0.9% sodium chloride injection retained more than 90% of their initial concentrations over 48 hours of storage at room temperature without protection from light. The observed variability in concentrations of these three compounds was within the limits of assay variability. An i.v. admixture containing metoclopramide 1.6 mg/mL, diphenhydramine hydrochloride 2 mg/mL, and dexamethasone sodium phosphate 0.16 mg/mL in 0.9% sodium chloride injection was chemically stable for 48 hours when stored at room temperature without light protection. Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  2. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    International Nuclear Information System (INIS)

    Sadeghi, Rahmat; Hosseini, Rahim; Jamehbozorg, Bahman

    2008-01-01

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied

  3. Effect of sodium phosphate salts on the thermodynamic properties of aqueous solutions of poly(ethylene oxide) 6000 at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Rahmat [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)], E-mail: rahsadeghi@yahoo.com; Hosseini, Rahim; Jamehbozorg, Bahman [Department of Chemistry, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

    2008-09-15

    Precise density, sound velocity, water activity, and phase diagram measurements have been carried out on polyethylene oxide (PEO) in aqueous solutions of sodium di-hydrogen phosphate, di-sodium hydrogen phosphate, and tri-sodium phosphate over a range of temperatures at atmospheric pressure. The experimental density and sound velocity data are used to calculate the apparent specific volume and isentropic compressibility as a function of temperature and concentration. It was found that both of the apparent specific volume and isentropic compressibility of PEO in aqueous solutions increase by increasing temperature and charge on the anion of electrolytes. The results show that the slope of constant water activity lines increased with increasing the temperature and charge on the anion of electrolytes and the vapour pressure depression for an aqueous (PEO + sodium phosphate) system is more than the sum of those for the corresponding binary solutions. Furthermore, the effect of temperature and type of anion of salt on the salting-out effect of polyethylene oxide by sodium phosphate salts has been studied.

  4. Bowel Preparation for Colonoscopy with Sodium Phosphate Solution versus Polyethylene Glycol-Based Lavage: A Multicenter Trial

    Directory of Open Access Journals (Sweden)

    S. Schanz

    2008-01-01

    Full Text Available Background: Adequate bowel preparation is essential for accurate colonoscopy. Both oral sodium phosphate (NaP and polyethylene glycol-based lavage (PEG-ELS are used predominantly as bowel cleansing modalities. NaP has gained popularity due to low drinking volume and lower costs. The purpose of this randomized multicenter observer blinded study was to compare three groups of cleansing (NaP, NaP + sennosides, PEG-ELS + sennosides in reference to tolerability, acceptance, and cleanliness. Patient and Methods: 355 outpatients between 18 and 75 years were randomized into three groups (A, B, C receiving NaP = A, NaP, and sennosides = B or PEG-ELS and sennosides = C. Gastroenterologists performing colonoscopies were blinded to the type of preparation. All patients documented tolerance and adverse events. Vital signs, premedication, completeness, discomfort, and complications were recorded. A quality score (0–4 of cleanliness was generated. Results: The three groups were similar with regard to age, sex, BMI, indication for colonoscopy, and comorbidity. Drinking volumes (L (A = 4.33 + 1.2, B = 4.56 + 1.18, C = 4.93 + 1.71 were in favor of NaP (P = .005. Discomfort from ingested fluid was recorded in A = 39.8% (versus C: P = .015, B = 46.6% (versus C: P = .147, and C = 54.6%. Differences in tolerability and acceptance between the three groups were statistically not significant. No differences in adverse events and the cleanliness effects occurred in the three groups (P = .113. The cleanliness quality scores 0–2 were calculated in A: 77.7%, B: 86.7%, and C: 85.2%. Conclusions: These data fail to demonstrate significant differences in tolerability, acceptance, and preparation quality between the three types of bowel preparation for colonoscopy. Cleansing with NaP was not superior to PEG-ELS.

  5. Spectrophotometric and chemometric methods for determination of imipenem, ciprofloxacin hydrochloride, dexamethasone sodium phosphate, paracetamol and cilastatin sodium in human urine

    Science.gov (United States)

    El-Kosasy, A. M.; Abdel-Aziz, Omar; Magdy, N.; El Zahar, N. M.

    2016-03-01

    New accurate, sensitive and selective spectrophotometric and chemometric methods were developed and subsequently validated for determination of Imipenem (IMP), ciprofloxacin hydrochloride (CIPRO), dexamethasone sodium phosphate (DEX), paracetamol (PAR) and cilastatin sodium (CIL) in human urine. These methods include a new derivative ratio method, namely extended derivative ratio (EDR), principal component regression (PCR) and partial least-squares (PLS) methods. A novel EDR method was developed for the determination of these drugs, where each component in the mixture was determined by using a mixture of the other four components as divisor. Peak amplitudes were recorded at 293.0 nm, 284.0 nm, 276.0 nm, 257.0 nm and 221.0 nm within linear concentration ranges 3.00-45.00, 1.00-15.00, 4.00-40.00, 1.50-25.00 and 4.00-50.00 μg mL- 1 for IMP, CIPRO, DEX, PAR and CIL, respectively. PCR and PLS-2 models were established for simultaneous determination of the studied drugs in the range of 3.00-15.00, 1.00-13.00, 4.00-12.00, 1.50-9.50, and 4.00-12.00 μg mL- 1 for IMP, CIPRO, DEX, PAR and CIL, respectively, by using eighteen mixtures as calibration set and seven mixtures as validation set. The suggested methods were validated according to the International Conference of Harmonization (ICH) guidelines and the results revealed that they were accurate, precise and reproducible. The obtained results were statistically compared with those of the published methods and there was no significant difference.

  6. Radiative properties and luminescence spectra of Sm{sup 3+} ion in zinc–aluminum–sodium-phosphate (ZANP) glasses

    Energy Technology Data Exchange (ETDEWEB)

    Brahmachary, K.; Rajesh, D.; Ratnakaram, Y.C., E-mail: ratnakaramsvu@gmail.com

    2015-05-15

    The fluorescence properties of different concentrations of Sm{sup 3+} doped zinc–aluminum–sodium-phosphate (ZANP) glasses were studied by the XRD, SEM, FTIR, TG–DTA, optical absorption, photoluminescence and decay cure analysis. X-ray diffraction profiles and SEM images confirmed the amorphous nature of the glass samples. Structural information of these glass matrices was provided by FTIR spectrum. Judd–Ofelt (J–O) theory was applied to the experimental oscillator strengths to evaluate three phenomenological J–O intensity parameters, Ω{sub λ} (λ=2, 4 and 6). Using J–O intensity parameters and emission spectra, various radiative parameters such as radiative transition probabilities (A{sub R}), radiative lifetimes (τ{sub R}), calculated and measured branching ratios (β{sub R} and β{sub m}), effective bandwidths (Δλ{sub eff}) and stimulated emission cross-sections (σ{sub P}) were calculated for observed emission transitions. The intensity of emission transitions with the variation of Sm{sup 3+} ion concentration was studied. The nature of decay curves of {sup 4}G{sub 5/2} level for different Sm{sup 3+} ion concentrations in ZANP glass was analyzed and obtained measured lifetimes (τ{sub exp}). Quantum efficiency of {sup 4}G{sub 5/2} level was calculated based on experimental and measured radiative lifetimes (τ{sub exp} and τ{sub R}). - Highlights: • The amorphous nature of glasses was confirmed due to lack of sharp peaks in the XRD profiles. • Higher covalency and rigidity were obtained in ZANPSm05 and ZANPSm15 glass matrices respectively. • The symmetric nature present in ZANP glass matrix is confirmed from MD transition, {sup 4}G{sub 5/2}→{sup 6}H{sub 7/2} of Sm{sup 3+} ion. • The decrease of intensity of emission transitions beyond 0.5 mol% is attributed to dipole–dipole interactions. • Among all the glass matrices studied, all the spectroscopic parameters are higher in ZANPSm05 glass matrix.

  7. Compatibility and Stability of VARUBI (Rolapitant) Injectable Emulsion Admixed with Intravenous Palonosetron Hydrochloride Injection and Dexamethasone Sodium Phosphate Injection.

    Science.gov (United States)

    Wu, George; Powers, Dan; Yeung, Stanley; Chen, Frank

    2018-01-01

    Prophylaxis or therapy with a combination of a neurokinin 1 (NK-1) receptor antagonist (RA), a 5-hydroxytryptamine-3 (5-HT3) RA, and dexamethasone is recommended by international antiemesis guidelines for the prevention of chemotherapy-induced nausea and vomiting for patients receiving highly emetogenic chemotherapy and for selected patients receiving moderately emetogenic chemotherapy. VARUBI (rolapitant) is a substance P/NK-1 RA that was recently approved by the U.S. Food and Drug Administration as an injectable emulsion in combination with other antiemetic agents in adults for the prevention of delayed nausea and vomiting associated with initial and repeat courses of emetogenic cancer chemotherapy, including, but not limited to, highly emetogenic chemotherapy. Palonosetron is one of the 5-HT3 RAs indicated for the prevention of nausea and/or vomiting associated with initial and repeat courses of emetogenic cancer therapy, including high-dose cisplatin. Herein, we describe the physical and chemical compatibility and stability of VARUBI injectable emulsion (166.5 mg/92.5 mL [1.8 mg/mL, free base], equivalent to 185 mg of rolapitant hydrochloride) admixed with palonosetron injection 0.25 mg free base in 5 mL (equivalent to 0.28 mg hydrochloride salt) and with either 5 mL (20 mg) or 2.5 mL (10 mg) of dexamethasone sodium phosphate. Admixtures were prepared and stored in VARUBI injectable emulsion ready-to-use glass vials as supplied by the rolapitant manufacturer and in four types of commonly used intravenous administration (tubing) sets. Assessment of the physical and chemical compatibility and stability of the admixtures in the VARUBI ready-to-use vials stored at room temperature (20°C to 25°C) under fluorescent light and under refrigeration (2°C to 8°C protected from light) was conducted at 0, 1, 6, 24, and 48 hours, and that of the admixtures in the intravenous tubing sets was evaluated at 0, 2, and 6 hours of storage at 20°C to 25°C. Physical stability

  8. XANES analysis of calcium and sodium phosphates and silicates and hydroxyapatite-Bioglass (registered) 45S5 co-sintered bioceramics

    International Nuclear Information System (INIS)

    Demirkiran, Hande; Hu Yongfeng; Zuin, Lucia; Appathurai, Narayana; Aswath, Pranesh B.

    2011-01-01

    Bioglass (registered) 45S5 was co-sintered with hydroxyapatite at 1200 deg. C. When small amounts ( 5 (PO 4 ) 2 SiO 4 and Na 3 Ca 6 (PO 4 ) 5 in an amorphous silicate matrix respectively. These chemistries show improved bioactivity compared to hydroxyapatite and are the subject of this study. The structure of several crystalline calcium and sodium phosphates and silicates as well as the co-sintered hydroxyapatite-Bioglass (registered) 45S5 bioceramics were examined using XANES spectroscopy. The nature of the crystalline and amorphous phases were studied using silicon (Si) and phosphorus (P) K- and L 2,3 -edge and calcium (Ca) K-edge XANES. Si L 2,3 -edge spectra of sintered bioceramic compositions indicates that the primary silicates present in these compositions are sodium silicates in the amorphous state. From Si K-edge spectra, it is shown that the silicates are in a similar structural environment in all the sintered bioceramic compositions with 4-fold coordination. Using P L 2,3 -edge it is clearly shown that there is no evidence of sodium phosphate present in the sintered bioceramic compositions. In the P K-edge spectra, the post-edge shoulder peak at around 2155 eV indicates that this shoulder to be more defined for calcium phosphate compounds with decreasing solubility and increasing thermodynamic stability. This shoulder peak is more noticeable in hydroxyapatite and β-TCP indicating greater stability of the phosphate phase. The only spectra that does not show a noticeable peak is the composition with Na 3 Ca 6 (PO 4 ) 5 in a silicate matrix indicating that it is more soluble compared to the other compositions.

  9. XANES analysis of calcium and sodium phosphates and silicates and hydroxyapatite-Bioglass (registered) 45S5 co-sintered bioceramics

    Energy Technology Data Exchange (ETDEWEB)

    Demirkiran, Hande [Graduate Student, Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX (United States); Hu Yongfeng; Zuin, Lucia [Beamline Scientist, Canadian Light Source, Saskatoon, SK (Canada); Appathurai, Narayana [Beamline Scientist, Synchrotron Radiation Center, Madison, WI (United States); Aswath, Pranesh B., E-mail: aswath@uta.edu [Materials Science and Engineering Department, University of Texas at Arlington, Arlington, TX (United States)

    2011-03-12

    Bioglass (registered) 45S5 was co-sintered with hydroxyapatite at 1200 deg. C. When small amounts (< 5 wt.%) of Bioglass (registered) 45S5 was added it behaved as a sintering aid and also enhanced the decomposition of hydroxyapatite to {beta}-tricalcium phosphate. However when 10 wt.% and 25 wt.% Bioglass (registered) 45S5 was used it resulted in the formation of Ca{sub 5}(PO{sub 4}){sub 2}SiO{sub 4} and Na{sub 3}Ca{sub 6}(PO{sub 4}){sub 5} in an amorphous silicate matrix respectively. These chemistries show improved bioactivity compared to hydroxyapatite and are the subject of this study. The structure of several crystalline calcium and sodium phosphates and silicates as well as the co-sintered hydroxyapatite-Bioglass (registered) 45S5 bioceramics were examined using XANES spectroscopy. The nature of the crystalline and amorphous phases were studied using silicon (Si) and phosphorus (P) K- and L{sub 2,3}-edge and calcium (Ca) K-edge XANES. Si L{sub 2,3}-edge spectra of sintered bioceramic compositions indicates that the primary silicates present in these compositions are sodium silicates in the amorphous state. From Si K-edge spectra, it is shown that the silicates are in a similar structural environment in all the sintered bioceramic compositions with 4-fold coordination. Using P L{sub 2,3}-edge it is clearly shown that there is no evidence of sodium phosphate present in the sintered bioceramic compositions. In the P K-edge spectra, the post-edge shoulder peak at around 2155 eV indicates that this shoulder to be more defined for calcium phosphate compounds with decreasing solubility and increasing thermodynamic stability. This shoulder peak is more noticeable in hydroxyapatite and {beta}-TCP indicating greater stability of the phosphate phase. The only spectra that does not show a noticeable peak is the composition with Na{sub 3}Ca{sub 6}(PO{sub 4}){sub 5} in a silicate matrix indicating that it is more soluble compared to the other compositions.

  10. Functionalized silica nanoparticles as a carrier for Betamethasone Sodium Phosphate: Drug release study and statistical optimization of drug loading by response surface method.

    Science.gov (United States)

    Ghasemnejad, M; Ahmadi, E; Mohamadnia, Z; Doustgani, A; Hashemikia, S

    2015-11-01

    Mesoporous silica nanoparticles with a hexagonal structure (SBA-15) were synthesized and modified with (3-aminopropyl) triethoxysilane (APTES), and their performance as a carrier for drug delivery system was studied. Chemical structure and morphology of the synthesized and modified SBA-15 were characterized by SEM, BET, TEM, FT-IR and CHN technique. Betamethasone Sodium Phosphate (BSP) as a water soluble drug was loaded on the mesoporous silica particle for the first time. The response surface method was employed to obtain the optimum conditions for the drug/silica nanoparticle preparation, by using Design-Expert software. The effect of time, pH of preparative media, and drug/silica ratio on the drug loading efficiency was investigated by the software. The maximum loading (33.69%) was achieved under optimized condition (pH: 1.8, time: 3.54 (h) and drug/silica ratio: 1.7). The in vitro release behavior of drug loaded particles under various pH values was evaluated. Finally, the release kinetic of the drug was investigated using the Higuchi and Korsmeyer-Peppas models. Cell culture and cytotoxicity assays revealed the synthesized product doesn't have any cytotoxicity against human bladder cell line 5637. Accordingly, the produced drug-loaded nanostructures can be applied via different routes, such as implantation and topical or oral administration. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Bond strength and interfacial morphology of orthodontic brackets bonded to eroded enamel treated with calcium silicate-sodium phosphate salts or resin infiltration.

    Science.gov (United States)

    Costenoble, Aline; Vennat, Elsa; Attal, Jean-Pierre; Dursun, Elisabeth

    2016-11-01

     To investigate the shear bond strength (SBS) of orthodontic brackets bonded to eroded enamel treated with preventive approaches and to examine the enamel/bracket interfaces.  Ninety-one brackets were bonded to seven groups of enamel samples: sound; eroded; eroded+treated with calcium silicate-sodium phosphate salts (CSP); eroded+infiltrated by ICON ® ; eroded+infiltrated by ICON ® and brackets bonded with 1-month delay; eroded+infiltrated by an experimental resin; and eroded+infiltrated by an experimental resin and brackets bonded with 1-month delay. For each group, 12 samples were tested in SBS and bond failure was assessed with the adhesive remnant index (ARI); one sample was examined using scanning electron microscopy (SEM).  Samples treated with CSP or infiltration showed no significant differences in SBS values with sound samples. Infiltrated samples followed by a delayed bonding showed lower SBS values. All of the values remained acceptable. The ARI scores were significantly higher for sound enamel, eroded, and treated with CSP groups than for all infiltrated samples. SEM examinations corroborated the findings.  Using CSP or resin infiltration before orthodontic bonding does not jeopardize the bonding quality. The orthodontic bonding should be performed shortly after the resin infiltration.

  12. High temperature aqueous potassium and sodium phosphate solutions: two-liquid-phase boundaries and critical phenomena, 275-4000C; potential applications for steam generators

    International Nuclear Information System (INIS)

    Marshall, W.L.

    1981-12-01

    Two-liquid-phase boundaries at temperatures between 275 and 400 0 C were determined for potassium phosphate and sodium phosphate aqueous solutions for compositions from 0 to 60 wt % dissolved salt. The stoichiometric mole ratios, K/PO 4 or Na/PO 4 , were varied from 1.00 to 2.12 and from 1.00 to 2.16 for the potassium and sodium systems, respectively. Liquid-vapor critical temperatures were also determined for most of the dilute liquid phases that formed. The minimum temperatures (below which a single solution existed) of two-liquid-phase formation were 360 0 C for the potassium system and 279 0 C for the sodium system at mole ratios of 2.00 and 2.16, respectively. For the sodium system at mole ratios greater than 2.16, solids crystallized at lower temperatures as expected from earlier studies. In contrast, potassium solutions that were explored at mole ratios from 2.12 to 3.16 and at temperatures below 360 0 C did not produce solid phases nor liquid-liquid immiscibilities. Aside from the generally unusual observations of two immiscible liquids in an aqueous inorganic salt system, the results could possibly be applied to the use of phosphate additives in steam power generators. 16 refs

  13. Passive water and ion transport by cotransporters

    DEFF Research Database (Denmark)

    Loo, D D; Hirayama, B A; Meinild, A K

    1999-01-01

    the Lp of control oocytes. Passive Na+ transport (Na+ leak) was obtained from the blocker-sensitive Na+ currents in the absence of substrates (glucose and GABA). 2. Passive Na+ and water transport through SGLT1 were blocked by phlorizin with the same sensitivity (inhibitory constant (Ki), 3-5 micro......1. The rabbit Na+-glucose (SGLT1) and the human Na+-Cl--GABA (GAT1) cotransporters were expressed in Xenopus laevis oocytes, and passive Na+ and water transport were studied using electrical and optical techniques. Passive water permeabilities (Lp) of the cotransporters were determined from......M). When Na+ was replaced with Li+, phlorizin also inhibited Li+ and water transport, but with a lower affinity (Ki, 100 microM). When Na+ was replaced by choline, which is not transported, the SGLT1 Lp was indistinguishable from that in Na+ or Li+, but in this case water transport was less sensitive...

  14. Human Sodium Phosphate Transporter 4 (hNPT4/SLC17A3) as a Common Renal Secretory Pathway for Drugs and Urate*

    Science.gov (United States)

    Jutabha, Promsuk; Anzai, Naohiko; Kitamura, Kenichiro; Taniguchi, Atsuo; Kaneko, Shuji; Yan, Kunimasa; Yamada, Hideomi; Shimada, Hidetaka; Kimura, Toru; Katada, Tomohisa; Fukutomi, Toshiyuki; Tomita, Kimio; Urano, Wako; Yamanaka, Hisashi; Seki, George; Fujita, Toshiro; Moriyama, Yoshinori; Yamada, Akira; Uchida, Shunya; Wempe, Michael F.; Endou, Hitoshi; Sakurai, Hiroyuki

    2010-01-01

    The evolutionary loss of hepatic urate oxidase (uricase) has resulted in humans with elevated serum uric acid (urate). Uricase loss may have been beneficial to early primate survival. However, an elevated serum urate has predisposed man to hyperuricemia, a metabolic disturbance leading to gout, hypertension, and various cardiovascular diseases. Human serum urate levels are largely determined by urate reabsorption and secretion in the kidney. Renal urate reabsorption is controlled via two proximal tubular urate transporters: apical URAT1 (SLC22A12) and basolateral URATv1/GLUT9 (SLC2A9). In contrast, the molecular mechanism(s) for renal urate secretion remain unknown. In this report, we demonstrate that an orphan transporter hNPT4 (human sodium phosphate transporter 4; SLC17A3) was a multispecific organic anion efflux transporter expressed in the kidneys and liver. hNPT4 was localized at the apical side of renal tubules and functioned as a voltage-driven urate transporter. Furthermore, loop diuretics, such as furosemide and bumetanide, substantially interacted with hNPT4. Thus, this protein is likely to act as a common secretion route for both drugs and may play an important role in diuretics-induced hyperuricemia. The in vivo role of hNPT4 was suggested by two hyperuricemia patients with missense mutations in SLC17A3. These mutated versions of hNPT4 exhibited reduced urate efflux when they were expressed in Xenopus oocytes. Our findings will complete a model of urate secretion in the renal tubular cell, where intracellular urate taken up via OAT1 and/or OAT3 from the blood exits from the cell into the lumen via hNPT4. PMID:20810651

  15. Preformulation and characterization of a lidocaine hydrochloride and dexamethasone sodium phosphate thermo-reversible and bioadhesive long-acting gel for intraperitoneal administration.

    Science.gov (United States)

    Arbelaez-Camargo, Diana; Suñé-Negre, Josep Maria; Roig-Carreras, Manel; García-Montoya, Encarna; Pérez-Lozano, Pilar; Miñarro-Carmona, Montserrat; Ticó-Grau, Josep Ramon

    2016-02-10

    The search for new formulations of anaesthetic agents that allow a localized administration and provide a prolonged effect is of great interest in the multimodal management of postoperative pain. The pre-formulation and characterization of a lidocaine and dexamethasone thermosensitive and bioadhesive long-acting gel for intraperitoneal administration was done as a tool in the management of pain in abdominal surgeries. The pre-formulation process was conducted by a systematic variation of the concentration of the different polymers, until setting it, in a suitable concentration that allowed an adequate gelation temperature. The poloxamer 407 (P407) was used as the main polymer; hydroxypropyl methylcellulose (HPMC) as the bioadhesive agent and polyvinyl pyrrolidone (PVP) to adjust the gelation temperature and physicochemical properties. The formulations were characterized by gelation temperature, pH, viscosity at 25°C and 37°C, gelation time, density and osmolality. Gelation temperature was decreased when increasing the concentration of hydroxypropyl methylcellulose and poloxamer 407, this effect was also observed when adding lidocaine hydrochloride and dexamethasone sodium phosphate to the formulations. The gelation temperature did not have statistically significant relation with the PVP concentration (P-value of 0.6797), even though, there is a tendency in the gelation temperature by varying it. Between the developed formulations, the 12.5/3.3/0.4% (P407/HPMC/PVP) formulation presents an appropriate gelation temperature, a suitable viscosity for administration by syringe, an adequate and stable pH and osmolality to prevent tissue damage and a correct gelation time that allowed the formation of a prolonged release implant. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Controlled transdermal iontophoresis for poly-pharmacotherapy: Simultaneous delivery of granisetron, metoclopramide and dexamethasone sodium phosphate in vitro and in vivo.

    Science.gov (United States)

    Cázares-Delgadillo, Jennyfer; Ganem-Rondero, Adriana; Merino, Virginia; Kalia, Yogeshvar N

    2016-03-31

    Iontophoresis has been used to deliver small molecules, peptides and proteins into and across the skin. In principle, it provides a controlled, non-invasive method for poly-pharmacotherapy since it is possible to formulate and to deliver multiple therapeutic agents simultaneously from the anodal and cathodal compartments. The objective of this proof-of-principle study was to investigate the simultaneous anodal iontophoretic delivery of granisetron (GST) and metoclopramide (MCL) and cathodal iontophoresis of dexamethasone sodium phosphate (DEX-P). In addition to validating the hypothesis, these are medications that are routinely used in combination to treat chemotherapy-induced emesis. Two preliminary in vitro studies using porcine skin were performed: Study 1 - effect of formulation composition on anodal co-iontophoresis of GST and MCL and Study 2 - combined anodal iontophoresis of GST (10mM) and MCL (110 mM) and cathodal iontophoresis of DEX-P (40 mM). The results from Study 1 demonstrated the dependence of GST/MCL transport on the respective drug concentrations when co-iontophoresed at 0.3 mA·cm(-2). Although they possess similar physicochemical properties, MCL seemed to be a more efficient charge carrier (JMCL=0.0591∗CMCLvs JGST=0.0414∗CGST). In Study 2, MCL permeation was markedly superior to that of GST (2324.83 ± 307.85 and 209.83 ± 24.84 μg·cm(-2), respectively); this was consistent with the difference in their relative concentrations; DEX-P permeation was 336.94 ± 71.91 μg·cm(-2). The in vivo studies in Wistar rats (10mM GST, 110 mM MCL and 40 mM DEX-P (0.5 mA·cm(-2) for 5h with Ag/AgCl electrodes and salt bridges) demonstrated that significant drug levels were achieved rapidly for each drug. This was most noticeable for dexamethasone (DEX) where relatively constant plasma levels were obtained from the 1 to 5h time-points; DEX-P was not detected in the plasma since it was completely hydrolyzed to the active metabolite. The calculated input

  17. Intra-individual comparison of magnesium citrate and sodium phosphate for bowel preparation at CT colonography: Automated volumetric analysis of residual fluid for quality assessment

    International Nuclear Information System (INIS)

    Bannas, P.; Bakke, J.; Munoz del Rio, A.; Pickhardt, P.J.

    2014-01-01

    Aim: To perform an objective, intra-individual comparison of residual colonic fluid volume and attenuation associated with the current front-line laxative magnesium citrate (MgC) versus the former front-line laxative sodium phosphate (NaP) at CT colonography (CTC). Materials and methods: This retrospective Health Insurance and Portability and Accountability Act-compliant study had institutional review board approval; informed consent was waived. The study cohort included 250 asymptomatic adults (mean age at index 56.1 years; 124 male/126 female) who underwent CTC screening twice over a 5 year interval. Colon catharsis at initial and follow-up screening employed single-dose NaP and double-dose MgC, respectively, allowing for intra-patient comparison. Automated volumetric analysis of residual colonic fluid volume and attenuation was performed on all 500 CTC studies. Colonic fluid volume <200 ml and mean attenuation between 300–900 HU were considered optimal. Paired t-test and McNemar's test were used to compare differences. Results: Residual fluid volumes <200 ml were recorded in 192 examinations (76.8%) following MgC and in 204 examinations (81.6%) following NaP (p = 0.23). The mean total residual fluid volume was 155 ± 114 ml for MgC and 143 ± 100 ml for NaP (p = 0.01). The attenuation range of 300–900 HU was significantly more frequent for MgC (n = 220, 88%) than for NaP (n = 127, 50.8%; p < 0.001). Mean fluid attenuation was significantly lower for MgC (700 ± 165 HU) than for NaP (878 ± 155 HU; p < 0.001). Concomitant presence of both optimal fluid volume and attenuation was significantly more frequent for MgC 65.2% than for NaP (38%; p < 0.001). Conclusions: Objective intra-individual comparison using automated volumetric analysis suggests that the replacement of NaP by MgC as the front-line laxative for CTC has not compromised overall examination quality. - Highlights: • Automated volumetric analysis provides

  18. Cotransport of water by Na¿-K¿-2Cl¿ cotransporters expressed in Xenopus oocytes

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Macaulay, Nanna

    2012-01-01

    The NKCC1 and NKCC2 isoforms of the mammalian Na¿–K¿–2Cl¿ cotransporter were expressed in Xenopus oocytes and the relation between external ion concentration and water fluxes determined.Water fluxes were determined from changes in the oocytes volume and ion fluxes from 86Rb+ uptake. Isotonic...

  19. Cotransport of water by the Na+-K+-2Cl(-) cotransporter NKCC1 in mammalian epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Herrera-Perez, José J; Zeuthen, Thomas

    2010-01-01

    Water transport by the Na+-K+-2Cl(-) cotransporter (NKCC1) was studied in confluent cultures of pigmented epithelial (PE) cells from the ciliary body of the fetal human eye. Interdependence among water, Na+ and Cl(-) fluxes mediated by NKCC1 was inferred from changes in cell water volume, monitored...

  20. Two-liquid-phase boundaries and critical phenomena at 275 to 4000C for high-temperature aqueous potassium phosphate and sodium phosphate solutions. Potential applications for steam generators

    International Nuclear Information System (INIS)

    Marshall, W.L.

    1982-01-01

    Two-liquid-phase boundaries at temperatures between 275 and 400 0 C were determined for potassium phosphate and sodium phosphate aqueous solutions for compositions from 0 to 60 wt % dissolved salt. The stoichiometric mole ratios, K/PO 4 or Na/PO 4 , were varied from 1.00 to 2.12 and from 1.00 to 2.16 for the potassium and sodium systems, respectively. Liquid-vapor critical temperatures were also determined for most of the dilute liquid phases that formed. The minimum temperatures (below which a single solution existed) of two-liquid-phase formation were 360 0 C for the potassium system and 279 0 C for the sodium system at mole ratios of 2.00 and 2.16, respectively. For the sodium system at mole ratios greater than 2.16, solids crystallized at lower temperatures as expected from earlier studies. In contrast, potassium solutions that were explored at mole ratios from 2.12 to 3.16 and at temperatures below 360 0 C did not produce solid phases or liquid-liquid immisibilities. Aside from the generally unusual observations of two immiscible liquids in an aqueous inorganic salt system, the results could possibly be applied to the use of phosphate additives in steam power generators

  1. Water transport by the renal Na(+)-dicarboxylate cotransporter

    DEFF Research Database (Denmark)

    Meinild, A K; Loo, D D; Pajor, A M

    2000-01-01

    . This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume...

  2. Cardiovascular effects of sodium glucose cotransporter 2 inhibitors

    Directory of Open Access Journals (Sweden)

    Santos Cavaiola T

    2018-04-01

    Full Text Available Tricia Santos Cavaiola, Jeremy Pettus Division of Endocrinology and Metabolism, University of California San Diego, San Diego, CA, USA Abstract: As the first cardiovascular (CV outcome trial of a glucose-lowering agent to demonstrate a reduction in the risk of CV events in patients with type 2 diabetes mellitus (T2DM, the EMPAgliflozin Removal of Excess Glucose: Cardiovascular OUTCOME Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME® trial, which investigated the sodium glucose cotransporter 2 (SGLT2 inhibitor empagliflozin, has generated great interest among health care professionals. CV outcomes data for another SGLT2 inhibitor, canagliflozin, have been published recently in the CANagliflozin CardioVascular Assessment Study (CANVAS Program, as have CV data from the retrospective real-world study Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors (CVD-REAL, which compared SGLT2 inhibitors with other classes of glucose-lowering drugs. This review discusses the results of these three studies and, with a focus on EMPA-REG OUTCOME, examines the possible mechanisms by which SGLT2 inhibitors may reduce CV risk in patients with T2DM. Keywords: canagliflozin, cardiovascular outcomes, dapagliflozin, empagliflozin, mechanisms, sodium glucose cotransporter 2 inhibitors

  3. KCl cotransport regulation and protein kinase G in cultured vascular smooth muscle cells.

    Science.gov (United States)

    Adragna, N C; Zhang, J; Di Fulvio, M; Lincoln, T M; Lauf, P K

    2002-05-15

    K-Cl cotransport is activated by vasodilators in erythrocytes and vascular smooth muscle cells and its regulation involves putative kinase/phosphatase cascades. N-ethylmaleimide (NEM) activates the system presumably by inhibiting a protein kinase. Nitrovasodilators relax smooth muscle via cGMP-dependent activation of protein kinase G (PKG), a regulator of membrane channels and transporters. We investigated whether PKG regulates K-Cl cotransport activity or mRNA expression in normal, PKG-deficient-vector-only-transfected (PKG-) and PKG-catalytic-domain-transfected (PKG+) rat aortic smooth muscle cells. K-Cl cotransport was calculated as the Cl-dependent Rb influx, and mRNA was determined by semiquantitative RT-PCR. Baseline K-Cl cotransport was higher in PKG+ than in PKG- cells (p <0.01). At 0.5 mM, NEM stimulated K-Cl cotransport by 5-fold in PKG- but not in PKG+ cells. However, NEM was more potent although less effective to activate K-Cl cotransport in normal (passage 1-3) and PKG+ than in PKG- cells. In PKG- cells, [(dihydroindenyl) oxy] alkanoic acid (300 mM) but not furosemide (1 mM) inhibited K-Cl cotransport. Furthermore, no difference in K-Cl cotransport mRNA expression was observed between these cells. In conclusion, this study shows that manipulation of PKG expression in vascular smooth muscle cells affects K-Cl cotransport activity and its activation by NEM.

  4. Effect of co-transporter blockers on non-synaptic epileptiform activity—computational simulation

    Science.gov (United States)

    Rodrigues Lopes, Mariana; Canton Santos, Luiz Eduardo; Márcio Rodrigues, Antônio; Antônio Duarte, Mario; Catelli Infantosi, Antonio Fernando; Alexandre Scorza, Fulvio; Arida, Ricardo Mario; Madureira, Ana Paula; Amaral da Silveira, Gilcélio; dos Santos, Ivans Carlos; Abrão Cavalheiro, Esper; Guimarães de Almeida, Antônio-Carlos

    2013-10-01

    The important role of cation-chloride co-transporters in epilepsy is being supported by an increasing number of investigations. However, enormous complexity is involved since the action of these co-transporters has effects on the ionic homeostasis influencing directly the neuronal excitability and the tissue propensity to sustain seizure. To unravel the complex mechanisms involving the co-transporters action during seizure, this paper shows simulations of non-synaptic epileptiform activity and the effect of the blockage of the two different types of cation-chloride co-transporters present in the brain: Na, K and 2Cl co-transporter (NKCC) and K and Cl co-transporter (KCC). The simulations were performed with an electrochemical model representing the non-synaptic structure of the granule cell layer of the dentate gyrus (DG) of the rat hippocampus. The simulations suggest: (i) the potassium clearance is based on the systemic interplay between the Na/K pump and the NKCC co-transporters; (ii) the simultaneous blockage of the NKCC of the neurons and KCC of glial cells acts efficiently suppressing the epileptiform activities; and (iii) the simulations show that depending on the combined blockage of the co-transporters, the epileptiform activities may be suppressed or enhanced.

  5. Characterization of glial cell K-Cl cotransport.

    Science.gov (United States)

    Gagnon, Kenneth B E; Adragna, Norma C; Fyffe, Robert E W; Lauf, Peter K

    2007-01-01

    The molecular mechanism of K-Cl cotransport (KCC) consists of at least 4 isoforms, KCC 1, 2, 3, and 4 which, in multiple combinations, exist in most cells, including erythrocytes and neuronal cells. We utilized reverse-transcriptase-polymerase chain reaction (RT-PCR) and ion flux studies to characterize KCC activity in an immortalized in vitro cell model for fibrous astrocytes, the rat C6 glioblastoma cell. Isoform-specific sets of oligonucleotide primers were synthesized for NKCC1, KCC1, KCC2, KCC3, KCC4, and also for NKCC1 and actin. K-Cl cotransport activity was determined by measuring either the furosemide-sensitive, or the Cl(-)-dependent bumetanide-insensitive Rb(+) (a K(+) congener) influx in the presence of the Na/K pump inhibitor ouabain. Rb(+) influx was measured at a fixed external Cl concentrations, [Cl(-)](e), as a function of varying external Rb concentrations, [Rb(+)](e), and at a fixed [Rb(+)](e) as a function of varying [Cl(-)](e), and with equimolar Cl replacement by anions of the chaotropic series. RT-PCR of C6 glioblastoma (C6) cells identified mRNA for three KCC isoforms (1, 3, and 4). NKCC1 mRNA was also detected. The apparent K(m) for KCC-mediated Rb(+) influx was 15 mM [Rb(+)](e), and V(max) 12.5 nmol Rb(+) * mg protein(-1) * minute(-1). The calculated apparent K(m) for external Cl(-) was 13 mM and V(max) 14.4 nmol Rb(+) * mg protein(-1) * minute(-1). The anion selectivity sequence of the furosemide-sensitive Rb(+) influx was Cl(-)>Br-=NO(3)(-)>I(-)=SCN(-)>Sfm(-) (sulfamate). Established activators of K-Cl cotransport, hyposmotic shock and N-ethylmaleimide (NEM) pretreatment, stimulated furosemide-sensitive Rb(+) influx. A ñ50% NEM-induced loss of intracellular K(+) was prevented by furosemide. We have identified by RT-PCR the presence of three distinct KCC isoforms (1, 3, and 4) in rat C6 glioblastoma cells, and functionally characterized the anion selectivity and kinetics of their collective sodium-independent cation-chloride cotransport

  6. Cardiovascular effects of sodium glucose cotransporter 2 inhibitors

    Science.gov (United States)

    Cavaiola, Tricia Santos; Pettus, Jeremy

    2018-01-01

    As the first cardiovascular (CV) outcome trial of a glucose-lowering agent to demonstrate a reduction in the risk of CV events in patients with type 2 diabetes mellitus (T2DM), the EMPAgliflozin Removal of Excess Glucose: Cardiovascular OUTCOME Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME®) trial, which investigated the sodium glucose cotransporter 2 (SGLT2) inhibitor empagliflozin, has generated great interest among health care professionals. CV outcomes data for another SGLT2 inhibitor, canagliflozin, have been published recently in the CANagliflozin CardioVascular Assessment Study (CANVAS) Program, as have CV data from the retrospective real-world study Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors (CVD-REAL), which compared SGLT2 inhibitors with other classes of glucose-lowering drugs. This review discusses the results of these three studies and, with a focus on EMPA-REG OUTCOME, examines the possible mechanisms by which SGLT2 inhibitors may reduce CV risk in patients with T2DM. PMID:29695924

  7. Water transport by the Na+/glucose cotransporter under isotonic conditions

    DEFF Research Database (Denmark)

    Zeuthen, T; Meinild, A K; Klaerke, D A

    1997-01-01

    Solute cotransport in the Na+/glucose cotransporter is directly coupled to significant water fluxes. The water fluxes are energized by the downhill fluxes of the other substrates by a mechanism within the protein itself. In the present paper we investigate the Na+/glucose cotransporter expressed ...... of water molecules and the number of Na+ ions transported, equivalent to 390 water molecules per glucose molecule. Unstirred layer effects are ruled out on the basis of experiments on native oocytes incubated with the ionophores gramicidin D or nystatin.......Solute cotransport in the Na+/glucose cotransporter is directly coupled to significant water fluxes. The water fluxes are energized by the downhill fluxes of the other substrates by a mechanism within the protein itself. In the present paper we investigate the Na+/glucose cotransporter expressed...... in Xenopus oocytes. We present a method which allows short-term exposures to sugar under voltage clamp conditions. We demonstrate that water is cotransported with the solutes despite no osmotic differences between the external and intracellular solutions. There is a fixed ratio of 195:1 between the number...

  8. Structural and functional significance of water permeation through cotransporters

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Gorraitz, Edurne; Her, Ka

    2016-01-01

    Membrane transporters, in addition to their major role as specific carriers for ions and small molecules, can also behave as water channels. However, neither the location of the water pathway in the protein nor their functional importance is known. Here, we map the pathway for water and urea...... through the intestinal sodium/glucose cotransporter SGLT1. Molecular dynamics simulations using the atomic structure of the bacterial transporter vSGLT suggest that water permeates the same path as Na+ and sugar. On a structural model of SGLT1, based on the homology structure of vSGLT, we identified...... to be due to alterations in steric hindrance to water and urea, and/or changes in protein folding caused by mismatching of side chains in the water pathway. Water permeation through SGLT1 and other transporters bears directly on the structural mechanism for the transport of polar solutes through...

  9. K-Cl cotransporters, cell volume homeostasis, and neurological disease.

    Science.gov (United States)

    Kahle, Kristopher T; Khanna, Arjun R; Alper, Seth L; Adragna, Norma C; Lauf, Peter K; Sun, Dandan; Delpire, Eric

    2015-08-01

    K(+)-Cl(-) cotransporters (KCCs) were originally characterized as regulators of red blood cell (RBC) volume. Since then, four distinct KCCs have been cloned, and their importance for volume regulation has been demonstrated in other cell types. Genetic models of certain KCCs, such as KCC3, and their inhibitory WNK-STE20/SPS1-related proline/alanine-rich kinase (SPAK) serine-threonine kinases, have demonstrated the evolutionary necessity of these molecules for nervous system cell volume regulation, structure, and function, and their involvement in neurological disease. The recent characterization of a swelling-activated dephosphorylation mechanism that potently stimulates the KCCs has pinpointed a potentially druggable switch of KCC activity. An improved understanding of WNK/SPAK-mediated KCC cell volume regulation in the nervous system might reveal novel avenues for the treatment of multiple neurological diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Characteristics and functions of Na-K-Cl cotransport in epithelial tissues

    International Nuclear Information System (INIS)

    O'Grady, S.M.; Palfrey, H.C.; Field, M.

    1987-01-01

    This review summarizes our present understanding of Na-K-Cl cotransport and its physiological role in absorption and secretion of electrolytes and water in epithelial tissues. In the past several years an extensive literature about this cotransporter has developed due to its widespread distribution in a variety of cell types and its essential role in fluid and electrolyte transport in several epithelial tissues. We summarize this literature and speculate on the future characterization of this transport system. Although this review focuses on cotransport as it relates to absorptive and secretory processes in epithelia, important information concerning the pharmacology, stoichiometry, and regulation of Na-K-Cl cotransport in nonepithelial systems (i.e., erythrocytes, fibroblasts, squid axon, etc.) has been included to supplement areas that are less well established in the epithelial literature. 114 references

  11. Cotransport of H+, lactate, and H2O in porcine retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Kiilgaard, Jens Folke; la Cour, Morten

    2003-01-01

    ) for the H(+) and lactate fluxes. The data suggest that H(2)O is cotransported along with H(+) and lactate ions in MCT1 localized to the retinal membrane. The study emphasizes the importance of this cotransporter in the maintenance of water homeostasis and pH in the subretinal space of a mammalian tissue...... and supports our previous study performed by an invasive technique in an amphibian tissue....

  12. Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules

    International Nuclear Information System (INIS)

    Crawford, J.M.; Gollan, J.L.

    1988-01-01

    Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer [ 14 C]bilirubin-[ 3 H]bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous [ 14 C]bilirubin monoglucuronide-[ 3 H]bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism

  13. Water permeation through the sodium-dependent galactose cotransporter vSGLT.

    Science.gov (United States)

    Choe, Seungho; Rosenberg, John M; Abramson, Jeff; Wright, Ernest M; Grabe, Michael

    2010-10-06

    It is well accepted that cotransporters facilitate water movement by two independent mechanisms: osmotic flow through a water channel in the protein and flow driven by ion/substrate cotransport. However, the molecular mechanism of transport-linked water flow is controversial. Some researchers believe that it occurs via cotransport, in which water is pumped along with the transported cargo, while others believe that flow is osmotic in response to an increase in intracellular osmolarity. In this letter, we report the results of a 200-ns molecular dynamics simulation of the sodium-dependent galactose cotransporter vSGLT. Our simulation shows that a significant number of water molecules cross the protein through the sugar-binding site in the presence as well as the absence of galactose, and 70-80 water molecules accompany galactose as it moves from the binding site into the intracellular space. During this event, the majority of water molecules in the pathway are unable to diffuse around the galactose, resulting in water in the inner half of the transporter being pushed into the intracellular space and replaced by extracellular water. Thus, our simulation supports the notion that cotransporters act as both passive water channels and active water pumps with the transported substrate acting as a piston to rectify the motion of water. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Regulation of K-Cl cotransport: from function to genes.

    Science.gov (United States)

    Adragna, N C; Di Fulvio, M; Lauf, P K

    2004-10-01

    This review intends to summarize the vast literature on K-Cl cotransport (COT) regulation from a functional and genetic viewpoint. Special attention has been given to the signaling pathways involved in the transporter's regulation found in several tissues and cell types, and more specifically, in vascular smooth muscle cells (VSMCs). The number of publications on K-Cl COT has been steadily increasing since its discovery at the beginning of the 1980s, with red blood cells (RBCs) from different species (human, sheep, dog, rabbit, guinea pig, turkey, duck, frog, rat, mouse, fish, and lamprey) being the most studied model. Other tissues/cell types under study are brain, kidney, epithelia, muscle/smooth muscle, tumor cells, heart, liver, insect cells, endothelial cells, bone, platelets, thymocytes and Leishmania donovani. One of the salient properties of K-Cl-COT is its activation by cell swelling and its participation in the recovery of cell volume, a process known as regulatory volume decrease (RVD). Activation by thiol modification with N-ethylmaleimide (NEM) has spawned investigations on the redox dependence of K-Cl COT, and is used as a positive control for the operation of the system in many tissues and cells. The most accepted model of K-Cl COT regulation proposes protein kinases and phosphatases linked in a chain of phosphorylation/dephosphorylation events. More recent studies include regulatory pathways involving the phosphatidyl inositol/protein kinase C (PKC)-mediated pathway for regulation by lithium (Li) in low-K sheep red blood cells (LK SRBCs), and the nitric oxide (NO)/cGMP/protein kinase G (PKG) pathway as well as the platelet-derived growth factor (PDGF)-mediated mechanism in VSMCs. Studies on VSM transfected cells containing the PKG catalytic domain demonstrated the participation of this enzyme in K-Cl COT regulation. Commonly used vasodilators activate K-Cl COT in a dose-dependent manner through the NO/cGMP/PKG pathway. Interaction between the

  15. Mini-review: regulation of the renal NaCl cotransporter by hormones.

    Science.gov (United States)

    Rojas-Vega, Lorena; Gamba, Gerardo

    2016-01-01

    The renal thiazide-sensitive NaCl cotransporter, NCC, is the major pathway for salt reabsorption in the distal convoluted tubule. The activity of this cotransporter is critical for regulation of several physiological variables such as blood pressure, serum potassium, acid base metabolism, and urinary calcium excretion. Therefore, it is not surprising that numerous hormone-signaling pathways regulate NCC activity to maintain homeostasis. In this review, we will provide an overview of the most recent evidence on NCC modulation by aldosterone, angiotensin II, vasopressin, glucocorticoids, insulin, norepinephrine, estradiol, progesterone, prolactin, and parathyroid hormone. Copyright © 2016 the American Physiological Society.

  16. SODIUM-POTASSIUM-CHLORIDE COTRANSPORT IN THE REGULATION OF VASCULAR MYOGENIC TONE

    Directory of Open Access Journals (Sweden)

    S. N. Orlov

    2014-01-01

    Full Text Available The article discusses the data on the functioning of Na+,K+,2Cl– cotransport – the carrier providing electroneutral symport of sodium, potassium and chloride, as well as molecular mechanisms of the regulation and physiological significance of this carrier. We analyzed the novel data on involvement of ubiquitous isoform of Na+,K+,2Cl–cotransporter (NKCC1 in regulation of vascular smooth muscle contraction, and role of this carrier in the regulation of cell volume and intracellular chloride concentration.

  17. Regulation of the sodium/potassium/chloride cotransporter by calcium and cyclic AMP in cultured vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Higgins, B.L.; Smith, L.; Smith, J.B.

    1987-01-01

    The activity of the Na/K/Cl cotransporter in smooth muscle cells cultured from rat aorta was assayed by measuring the initial rate of furosemide-inhibitable 86 Rb influx or efflux. Five uM furosemide or 0.2 uM bumetanide inhibited influx by 50%. Furosemide-inhibitable 86 Rb influx depended on the presence of all 3 ions in the external medium. The dependence on Na and K was hyperbolic with apparent Km values of 45 and 5 mM, respectively. The dependence on Cl was sigmoidal. Assuming a stoichiometry of 1:1:2 for Na:K:Cl, a Km for Cl of 60 mM was obtained from a Hofstee plot of the data. Rapidly growing cells had 3 fold higher cotransport activity than quiescent cells. Angiotensin II (ANG) stimulated furosemide-inhibitable 86 Rb efflux by 2 fold. An ANG receptor antagonist prevented ANG from increasing cotransport activity. Two calcium ionophores, A23187 and ionomycin, increased cotransport activity by 2 fold. Phorbol myristate acetate had no effect on cotransport activity. Isoproterenol, dibutyryl cyclic AMP, cholera toxin, or methylisobutylxanthine inhibited furosemide-sensitive 86 Rb influx by 35 to 50%. From these findings they conclude that increasing cytoplasmic free calcium stimulates cotransport activity, whereas increasing cellular cyclic AMP inhibits the cotransporter

  18. Isotonic transport by the Na+-glucose cotransporter SGLT1 from humans and rabbit

    DEFF Research Database (Denmark)

    Zeuthen, T; Meinild, A K; Loo, D D

    2001-01-01

    water transport was divided about equally between cotransport, osmosis across the SGLT1 and osmosis across the native oocyte membrane. 6. Coexpression of AQP1 with the SGLT1 increased the water permeability more than 10-fold and steady state isotonic transport was achieved after less than 2 s of sugar......1. In order to study its role in steady state water transport, the Na+-glucose cotransporter (SGLT1) was expressed in Xenopus laevis oocytes; both the human and the rabbit clones were tested. The transport activity was monitored as a clamp current and the flux of water followed optically...... as the change in oocyte volume. 2. SGLT1 has two modes of water transport. First, it acts as a molecular water pump: for each 2 Na+ and 1 sugar molecule 264 water molecules were cotransported in the human SGLT1 (hSGLT1), 424 for the rabbit SGLT1 (rSGLT1). Second, it acts as a water channel. 3. The cotransport...

  19. Water permeability of Na+-K+-2Cl- cotransporters in mammalian epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Herrera-Perez, José Jaime; Bundgaard, Magnus

    2005-01-01

    Water transport properties of the Na+-K+-2Cl- cotransporter (NKCC) were studied in cultures of pigmented epithelial cells (PE) from the ciliary body of the eye. Here, the membrane that faces upwards contains NKCCs and can be subjected to rapid changes in bathing solution composition and osmolarity...

  20. Vasopressin induces phosphorylation of the thiazide-sensitive sodium chloride cotransporter in the distal convoluted tubule

    DEFF Research Database (Denmark)

    Pedersen, Nis Borbye; Hofmeister, Marlene Vind; Rosenbaek, Lena L

    2010-01-01

    The thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC) is important for renal electrolyte balance and its phosphorylation causes an increase in its transport activity and cellular localization. Here, we generated phospho-specific antibodies against two conserved N-terminal phosphorylation sites...

  1. Functional assessment of sodium chloride cotransporter NCC mutants in polarized mammalian epithelial cells

    DEFF Research Database (Denmark)

    Rosenbaek, Lena L; Rizzo, Federica; MacAulay, Nanna

    2017-01-01

    The thiazide-sensitive sodium chloride cotransporter NCC is important for maintaining serum sodium (Na(+)) and, indirectly, serum potassium (K(+)) levels. Functional studies on NCC have used cell lines with native NCC expression, transiently transfected nonpolarized cell lines, or Xenopus laevis...

  2. K-Cl cotransport function and its potential contribution to cardiovascular disease.

    Science.gov (United States)

    Adragna, Norma C; Lauf, Peter K

    2007-12-01

    K-Cl cotransport is the coupled electroneutral movement of K and Cl ions carried out by at least four protein isoforms, KCC1-4. These transporters belong to the SLC12A family of coupled cotransporters and, due to their multiple functions, play an important role in the maintenance of cellular homeostasis. Significant information exists on the overall function of these transporters, but less is known about the role of the specific isoforms. Most functional studies were done on K-Cl cotransport fluxes without knowing the molecular details, and only recently attention has been paid to the isoforms and their individual contribution to the fluxes. This review summarizes briefly and updates the information on the overall functions of this transporter, and offers some ideas on its potential contribution to the pathophysiological basis of cardiovascular disease. By virtue of its properties and the cellular ionic distribution, K-Cl cotransport participates in volume regulation of the nucleated and some enucleated cells studied thus far. One of the hallmarks in cardiovascular disease is the inability of the organism to maintain water and electrolyte balance in effectors and/or target tissues. Oxidative stress is another compounding factor in cardiovascular disease and of great significance in our modern life styles. Several functions of the transporter are modulated by oxidative stress, which in turn may cause the transporter to operate in either "overdrive" with the purpose to counteract homeostatic changes, or not to respond at all, again setting the stage for pathological changes leading to cardiovascular disease. Intracellular Mg, a second messenger, acts as an inhibitor of K-Cl cotransport and plays a crucial role in regulating the activity of protein kinases and phosphatases, which, in turn, regulate a myriad of cellular functions. Although the role of Mg in cardiovascular disease has been dealt with for several decades, this chapter is evolving nowadays at a faster

  3. Sodium Glucose Cotransporter 2 Inhibitors in the Treatment of Diabetes Mellitus : Cardiovascular and Kidney Effects, Potential Mechanisms, and Clinical Applications

    NARCIS (Netherlands)

    Heerspink, Hiddo J. L.; Perkins, Bruce A.; Fitchett, David H.; Husain, Mansoor; Cherney, David Z. I.

    2016-01-01

    Sodium-glucose cotransporter-2 (SGLT2) inhibitors, including empagliflozin, dapagliflozin, and canagliflozin, are now widely approved antihyperglycemic therapies. Because of their unique glycosuric mechanism, SGLT2 inhibitors also reduce weight. Perhaps more important are the osmotic diuretic and

  4. The human Na+-glucose cotransporter is a molecular water pump

    DEFF Research Database (Denmark)

    Meinild, A; Klaerke, D A; Loo, D D

    1998-01-01

    1. The human Na+-glucose cotransporter (hSGLT1) was expressed in Xenopus laevis oocytes. The transport activity, given by the Na+ current, was monitored as a clamp current and the concomitant flux of water followed optically as the change in oocyte volume. 2. When glucose was added to the bathing...... solution there was an abrupt increase in clamp current and an immediate swelling of the oocyte. The transmembrane transport of two Na+ ions and one sugar molecule was coupled, within the protein itself, to the influx of 210 water molecules. 3. This stoichiometry was constant and independent of the external...... parameters: Na+ concentrations, sugar concentrations, transmembrane voltages, temperature and osmotic gradients. 4. The cotransport of water occurred in the presence of adverse osmotic gradients. In accordance with the Gibbs equation, energy was transferred within the protein from the downhill fluxes of Na...

  5. Characterization of a novel phosphorylation site in the sodium-chloride cotransporter, NCC

    DEFF Research Database (Denmark)

    Rosenbaek, L L; Assentoft, M; Pedersen, N B

    2012-01-01

    The sodium-chloride cotransporter, NCC, is essential for renal electrolyte balance. NCC function can be modulated by protein phosphorylation. In this study, we characterized the role and physiological regulation of a novel phosphorylation site in NCC at Ser124 (S124). Novel phospho-specific antib......The sodium-chloride cotransporter, NCC, is essential for renal electrolyte balance. NCC function can be modulated by protein phosphorylation. In this study, we characterized the role and physiological regulation of a novel phosphorylation site in NCC at Ser124 (S124). Novel phospho......-related proline-alanine-rich kinase and oxidative stress-response kinases (SPAK and OSR1) were not able to phosphorylate NCC at S124. Protein kinase arrays identified multiple kinases that were able to bind to the region surrounding S124. Four of these kinases (IRAK2, CDK6/Cyclin D1, NLK and m...

  6. Positioning of sodium-glucose cotransporter-2 inhibitors in national and international guidelines.

    Science.gov (United States)

    Morillas, Carlos

    2016-11-01

    Sodium-glucose cotransporter-2 inhibitors (SGLT2-i) selectively and reversibly inhibit sodium-glucose cotransporter-2 (SGLT2), promoting renal glucose excretion and reducing plasma glycaemia. By increasing renal glucose excretion, these drugs favour a negative energy balance, leading to weight loss. Their glucoselowering effect is independent of insulin. Although these drugs have only recently been developed, they have been included in all the main national and international guidelines since 2014. The present review summarises the most important recommendations on the use of SGLT2 in patients with DM2 contained in the most recently published guidelines and consensus statements. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  7. Na+ -K+ -2Cl- Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia.

    Science.gov (United States)

    Delpire, Eric; Gagnon, Kenneth B

    2018-03-25

    Two genes encode the Na + -K + -2Cl - cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na + , 1K + , and 2Cl - across the plasma membrane of cells. Na + -K + -2Cl - cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na + /K + pump. In many cells, NKCC1 accumulates Cl - above its electrochemical potential equilibrium, thereby facilitating Cl - channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca 2+ channels, leading to Ca 2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl - conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl - . In combination with the Na + /K + pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl - -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K + -driven fluid secretion in inner ear, and possibly in Na + -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na + /K + pump participates in reabsorbing 30% of the glomerular-filtered Na + . Overall, many critical physiological functions are maintained by the activity of the two Na + -K + -2Cl - cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

  8. Cotransport of sodium and chloride by the adult mammalian choroid plexus

    Energy Technology Data Exchange (ETDEWEB)

    Johanson, C.E.; Sweeney, S.M.; Parmelee, J.T.; Epstein, M.H. (Brown Univ./Rhode Island Hospital, Providence (USA))

    1990-02-01

    Cerebrospinal fluid formation stems primarily from the transport of Na and Cl in choroid plexus (CP). To characterize properties and modulation of choroidal transporters, we tested diuretics and other agents for ability to alter ion transport in vitro. Adult Sprague-Dawley rats were the source of CPs preincubated with drug for 20 min and then transferred to cerebrospinal fluid (CSF) medium containing 22Na or 36Cl with (3H)mannitol (extracellular correction). Complete base-line curves were established for cellular uptake of Na and Cl at 37 degrees C. The half-maximal uptake occurred at 12 s, so it was used to assess drug effects on rate of transport (nmol Na or Cl/mg CP). Bumetanide (10(-5) and 10(-4) M) decreased uptake of Na and Cl with maximal inhibition (up to 45%) at 10(-5) M. Another cotransport inhibitor, furosemide (10(-4) M), reduced transport of Na by 25% and Cl by 33%. However, acetazolamide (10(-4) M) and atriopeptin III (10(-7) M) significantly lowered uptake of Na (but not Cl), suggesting effect(s) other than on cotransport. The disulfonic stilbene 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS; 10(-4) M), known to inhibit Cl-HCO3 exchange, substantially reduced the transport of 36Cl. Bumetanide plus DIDS (both 10(-4) M) caused additive inhibition of 90% of Cl uptake, which provides strong evidence for the existence of both cotransport and antiport Cl carriers. Overall, this in vitro analysis, uncomplicated by variables of blood flow and neural tone, indicates the presence in rat CP of the cotransport of Na and Cl in addition to the established Na-H and Cl-HCO3 exchangers.

  9. Cotransport of water and solutes in plant membranes: The molecular basis, and physiological functions

    Directory of Open Access Journals (Sweden)

    Lars H. Wegner

    2017-03-01

    Full Text Available Current concepts of plant membrane transport are based on the assumption that water and solutes move across membranes via separate pathways. According to this view, coupling between the fluxes is more or less exclusively constituted via the osmotic force that solutes exert on water transport. This view is questioned here, and experimental evidence for a cotransport of water and solutes is reviewed. The overview starts with ion channels that provide pathways for both ion and water transport, as exemplified for maxi K+ channels from cytoplasmic droplets of Chara corallina. Aquaporins are usually considered to be selective for water (just allowing for slippage of some other small, neutral molecules. Recently, however, a “dual function” aquaporin has been characterized from Arabidopsis thaliana (AtPIP2.1 that translocates water and at the same time conducts cations, preferentially Na+. By analogy with mammalian physiology, other candidates for solute-water flux coupling are cation-chloride cotransporters of the CCC type, and transporters of sugars and amino acids. The last part is dedicated to possible physiological functions that could rely on solute-water cotransport. Among these are the generation of root pressure, refilling of embolized xylem vessels, fast turgor-driven movements of leaves, cell elongation (growth, osmoregulation and adjustment of buoyancy in marine algae. This review will hopefully initiate further research in the field.

  10. Tyrosine transport in winter flounder intestine: Interaction with Na+-K+-2Cl- cotransport

    International Nuclear Information System (INIS)

    Musch, M.W.; McConnell, F.M.; Goldstein, L.; Field, M.

    1987-01-01

    Tyrosine absorption across the brush border of the intestinal epithelium of the winter flounder Pseudopleuronectes americanus was studied in Ussing chambers modified to determine early rates of uptake. At 0.1 mM tyrosine, the 4-min rate of uptake (influx) of tyrosine across the brush border averaged 37.5 nmol·cm -2 ·h -1 . Omission of Na decreased influx by 60%, indicting that tyrosine influx occurs, at least in part, by a Na-coupled process. Ouabain inhibited influx by 80%. Inhibition of brush border Na + -K + -2Cl - cotransport by bumetanide, 8-bromo-cyclic GMP, or Cl replacement stimulated tyrosine influx 2.5- to 4-fold. However, atriopeptin III, which also inhibits Na + -K + -2Cl - cotransport, did not stimulate tyrosine influx. Cyclic AMP, which does not appear to inhibit ion cotransport, did not stimulate tyrosine influx. Both cyclic GMP and bumetanide also stimulated the net mucosa-to-serosa tyrosine flux (43 and 29%, respectively) and increased the cellular concentration of tyrosine by 50%. Thus tyrosine's influx is increased to a greater extent than is its transmural flux or its cellular concentration, suggesting that the main change occurs at the brush border and represents large increases in both influx and efflux of tyrosine across this membrane

  11. Modeling glial contributions to seizures and epileptogenesis: cation-chloride cotransporters in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Zeid M Rusan

    Full Text Available Flies carrying a kcc loss-of-function mutation are more seizure-susceptible than wild-type flies. The kcc gene is the highly conserved Drosophila melanogaster ortholog of K+/Cl- cotransporter genes thought to be expressed in all animal cell types. Here, we examined the spatial and temporal requirements for kcc loss-of-function to modify seizure-susceptibility in flies. Targeted RNA interference (RNAi of kcc in various sets of neurons was sufficient to induce severe seizure-sensitivity. Interestingly, kcc RNAi in glia was particularly effective in causing seizure-sensitivity. Knockdown of kcc in glia or neurons during development caused a reduction in seizure induction threshold, cell swelling, and brain volume increase in 24-48 hour old adult flies. Third instar larval peripheral nerves were enlarged when kcc RNAi was expressed in neurons or glia. Results suggest that a threshold of K+/Cl- cotransport dysfunction in the nervous system during development is an important determinant of seizure-susceptibility in Drosophila. The findings presented are the first attributing a causative role for glial cation-chloride cotransporters in seizures and epileptogenesis. The importance of elucidating glial cell contributions to seizure disorders and the utility of Drosophila models is discussed.

  12. Sodium-glucose co-transporter type 2 inhibitors reduce evening home blood pressure in type 2 diabetes with nephropathy.

    Science.gov (United States)

    Takenaka, Tsuneo; Kishimoto, Miyako; Ohta, Mari; Tomonaga, Osamu; Suzuki, Hiromichi

    2017-05-01

    The effects of sodium-glucose co-transporter type 2 inhibitors on home blood pressure were examined in type 2 diabetes with nephropathy. The patients with diabetic nephropathy were screened from medical records in our hospitals. Among them, 52 patients who measured home blood pressure and started to take sodium-glucose co-transporter type 2 inhibitors were selected. Clinical parameters including estimated glomerular filtration rate, albuminuria and home blood pressure for 6 months were analysed. Sodium-glucose co-transporter type 2 inhibitors (luseogliflozin 5 mg/day or canagliflozin 100 mg/day) reduced body weight, HbA1c, albuminuria, estimated glomerular filtration rate and office blood pressure. Although sodium-glucose co-transporter type 2 inhibitors did not alter morning blood pressure, it reduced evening systolic blood pressure. Regression analyses revealed that decreases in evening blood pressure predicted decrements in albuminuria. The present data suggest that sodium-glucose co-transporter type 2 inhibitors suppress sodium overload during daytime to reduce evening blood pressure and albuminuria.

  13. Human NKCC2 cation–Cl– co-transporter complements lack of Vhc1 transporter in yeast vacuolar membranes.

    Science.gov (United States)

    Petrezselyova, Silvia; Dominguez, Angel; Herynkova, Pavla; Macias, Juan F; Sychrova, Hana

    2013-10-01

    Cation–chloride co-transporters serve to transport Cl– and alkali metal cations. Whereas a large family of these exists in higher eukaryotes, yeasts only possess one cation–chloride co-transporter, Vhc1, localized to the vacuolar membrane. In this study, the human cation–chloride co-transporter NKCC2 complemented the phenotype of VHC1 deletion in Saccharomyces cerevisiae and its activity controlled the growth of salt-sensitive yeast cells in the presence of high KCl, NaCl and LiCl. A S. cerevisiae mutant lacking plasma-membrane alkali–metal cation exporters Nha1 and Ena1-5 and the vacuolar cation–chloride co-transporter Vhc1 is highly sensitive to increased concentrations of alkali–metal cations, and it proved to be a suitable model for characterizing the substrate specificity and transport activity of human wild-type and mutated cation–chloride co-transporters. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Comparison of colon-cleansing methods in preparation for colonoscopy - Comparative efficacy of solutions of mannitol, sodium picosulfate and monobasic and dibasic sodium phosphates Estudo comparativo entre as soluções de manitol, picossulfato de sódio e fosfato monobásico e dibásico de sódio no preparo de cólon para colonoscopia

    Directory of Open Access Journals (Sweden)

    Paulo Miki Jr

    2008-01-01

    Full Text Available PURPOSE: Colonoscopy plays an essential role in the therapeutic and diagnostic approach in various colonic pathologies, the aim of the present study was to compare three solutions and their efficacy for the bowel preparation in adult patients submitted to elective colonoscopy. METHODS: Sixty patients were randomly divided into three groups of 20 each. Each group was submitted to a bowel preparation with one of the following solutions: 10% manitol, sodium picosulphate or sodium phosphate. The parameters evaluated were: taste, tolerance, associated side effects and quality of cleansing. Postural blood pressure and pulse rate as well as serum sodium, potassium, calcium and phosphate were compared. RESULTS: Sodium phosphate and 10% manitol solutions provided superior results in terms of colon cleansing compared to sodium picosulphate solution. All serum electrolytes evaluated were significantly altered in the three groups, without important clinical signs. DISCUSSION: High levels of serum phosphate were the most striking alteration in patients prepared with sodium phosphate solution, again with no clinical signs. Variations related to blood pressure and pulse rate suggested contraction of intravascular volume, with no clinical effects. CONCLUSION: Sodium phosphate and 10% manitol solutions are equivalent in providing good quality colon cleansing, with no significant side effects that could compromise the procedure.INTRODUÇÃO: A colonoscopia é exame fundamental na avaliação das doenças do cólon e na abordagem terapêutica de determinado grupo de patologias. O preparo intestinal é obrigatório para a realização das colonoscopias eletivas, e a qualidade encontra-se relacionada ao sucesso do procedimento. Comparou-se três soluções para limpeza anterógrada do cólon em pacientes adultos, submetidos à colonoscopia. METODOS: Sessenta pacientes foram distribuídos em três grupos de vinte. Cada grupo realizou o preparo do cólon com uma das

  15. Sodium-glucose cotransporter 2 inhibition and health benefits: The Robin Hood effect.

    Science.gov (United States)

    Kalra, Sanjay; Jain, Arpit; Ved, Jignesh; Unnikrishnan, A G

    2016-01-01

    This review discusses two distinct, yet related, mechanisms of sodium-glucose cotransporter 2 (SGLT2) inhibition: Calorie restriction mimicry (CRM) and pro-ketogenic effect, which may explain their cardiovascular benefits. We term these adaptive CRM and pro-ketogenic effects of SGLT2 inhibition, the Robin Hood hypothesis. In English history, Robin Hood was a "good person," who stole from the rich and helped the poor. He supported redistribution of resources as he deemed fit for the common good. In a similar fashion, SGLT2 inhibition provides respite to the overloaded glucose metabolism while utilizing lipid stores for energy production.

  16. Sodium-glucose cotransporter 2 inhibition and health benefits: The Robin Hood effect

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2016-01-01

    Full Text Available This review discusses two distinct, yet related, mechanisms of sodium-glucose cotransporter 2 (SGLT2 inhibition: Calorie restriction mimicry (CRM and pro-ketogenic effect, which may explain their cardiovascular benefits. We term these adaptive CRM and pro-ketogenic effects of SGLT2 inhibition, the Robin Hood hypothesis. In English history, Robin Hood was a "good person," who stole from the rich and helped the poor. He supported redistribution of resources as he deemed fit for the common good. In a similar fashion, SGLT2 inhibition provides respite to the overloaded glucose metabolism while utilizing lipid stores for energy production.

  17. Sodium-glucose cotransporter 2 inhibitor use: A pharmaco-ergonomic qualification tool

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2017-01-01

    Full Text Available Pharmaco-ergonomics implies tailoring the drug therapy to an individual patient's requirement(s. The development of sodium-glucose cotransporter 2 inhibitor (SGLT2-i agents has impelled multiple clinical considerations, in the management of type-2 diabetes. This paper attempts to summarize the pharmaco-ergonomic considerations for these agents, in the form of an SGLT2-i qualification tool, based on a clinical score. This tool may serve as a simple and inexpensive practical guide, to optimize the risk-benefit considerations for SGLT2-i agents.

  18. Contribution of the basolateral isoform of the Na-K-2Cl- cotransporter (NKCC1/BSC2) to renin secretion

    DEFF Research Database (Denmark)

    Castrop, Hayo; Lorenz, John N; Hansen, Pernille B

    2005-01-01

    Acute administration of loop diuretics like furosemide leads to a stimulation of renin secretion, an effect thought to result from inhibition of Na-K-2Cl cotransporter (NKCC2)-mediated salt transport at the luminal surface of the macula densa (MD). However, loop diuretics also inhibit NKCC1......, the second isoform of the Na-K-2Cl cotransporter, with similar potency. In the present study, we examined the influence of furosemide on renin secretion in NKCC1-deficient mice to distinguish between effects of the loop diuretic involving NKCC2 and, by implication, the MD pathway, and effects that might...

  19. Inhibition of Na+-P/sub i/ cotransporter in small gut brush border by phosphonocarboxylic acids

    International Nuclear Information System (INIS)

    Loghman-Adham, M.; Szczepsanska-Konkel, M.; Yusufi, A.N.K.; Van Scoy, M.; Dousa, T.P.

    1987-01-01

    The authors examined the effect of phosphonoformic acid (PFA) and phosphonoacetic acid (PAA) upon Na + -P/sub i/ cotransport in brush-border membrane (BBM) from small gut of rat. Both PFA and PAA inhibited the Na + gradient-dependent uptake of 32 P/sub i/ by BBM vesicles (BBMV) prepared from intestinal mucosa but had no effect on Na + -dependent uptakes of D-[ 3 H]glucose, L-[ 3 H]proline, or [ 14 C]succinate. The uptake in the absence of Na + gradient, or uptake at equilibrium period (180 min), was not affected by PFA or by PAA. A chemical analogue of PFA and PAA, phosphonopropionic acid, had only a minor inhibitory effect and phenylphosphonic acid was inactive. Neither PFA nor PAA influenced the activity of rat intestinal BBM alkaline phosphatase. The BBMV from rat jejunum had a much higher capacity for Na + gradient-dependent uptake of 32 P/sub i/ than BBMV from duodenum or ileum. The inhibition of BBMV 32 P/sub i/ transport across rat jejunum by PFA is competitive. They suggest that PFA and PAA are specific inhibitors of Na + gradient-dependent uptake of P/sub i/ by BBMV from small intestinal mucosa and that they could serve as useful experimental tools for the studies of intestinal Na + -P/sub i/ cotransport

  20. Nanomaterials-Based Approaches for the Modulation of Sodium Bicarbonate Cotransporters

    Directory of Open Access Journals (Sweden)

    Jeong Hee Hong

    2015-01-01

    Full Text Available HCO3- and fluid secretion are major functions of all epithelia, and alterations in HCO3- secretion by sodium bicarbonate cotransporters are associated with many epithelial diseases, such as renal, ocular, and dental abnormalities. Electrolyte and fluid exits are synergistically mediated by the intracellular second messengers, cAMP and Ca2+, and this raises the possibility that ion transporters are involved in simple secretion and more complicated forms of regulation. Evidence indicates that HCO3- transport is regulated by the assemblage of Na+-HCO3- cotransporters (NBCs into complexes by multiple regulatory factors. Recently the specific regulatory functions of factors that interact with NBCe1, especially NBCe1-B, have been elucidated. In this review, I focus on the structural characteristics of electrogenic NBCe1, pathophysiology of NBCe1, and molecular mechanisms responsible for transporter regulation. Moreover I propose the possibility to apply nanomaterials combined with regulatory factors for modulating the activity of NBC transporters as a potential development of therapeutic drug.

  1. NONOates regulate KCl cotransporter-1 and -3 mRNA expression in vascular smooth muscle cells.

    Science.gov (United States)

    Di Fulvio, Mauricio; Lauf, Peter K; Shah, Shalin; Adragna, Norma C

    2003-05-01

    Nitric oxide (NO) donors regulate KCl cotransport (KCC) activity and cotransporter-1 and -3 (KCC1 and KCC3) mRNA expression in sheep erythrocytes and in primary cultures of rat vascular smooth muscle cells (VSMCs), respectively. In this study, we used NONOates as rapid and slow NO releasers to provide direct evidence implicating NO as a regulator of KCC3 gene expression at the mRNA level. In addition, we used the expression of KCC3 mRNA to further investigate the mechanism of action of these NO donors at the cellular level. Treatment of VSMCs with rapid NO releasers, like NOC-5 and NOC-9, as well as with the direct NO-independent soluble guanylyl cyclase (sGC) stimulator YC-1, acutely increased KCC3 mRNA expression in a concentration- and time-dependent manner. The slow NO releaser NOC-18 had no effect on KCC3 gene expression. A specific NO scavenger completely prevented the NONOate-induced KCC3 mRNA expression. Inhibition of sGC with LY-83583 blocked the NONOate- and YC-1-induced KCC3 mRNA expression. This study shows that in primary cultures of rat VSMCs, the fast NO releasers NOC-9 and NOC-5, but not the slow NO releaser NOC-18, acutely upregulate KCC3 mRNA expression in a NO/sGC-dependent manner.

  2. Metal Oxide Decomposition In Hydrothermal Alkaline Sodium Phosphate Solutions

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Ziemniak

    2003-09-24

    Alkaline hydrothermal solutions of sodium orthophosphate (2.15 < Na/P < 2.75) are shown to decompose transition metal oxides into two families of sodium-metal ion-(hydroxy)phosphate compounds. Equilibria for these reactions are quantified by determining phosphate concentration-temperature thresholds for decomposition of five oxides in the series: Ti(IV), Cr(III), Fe(III, II), Ni(II) and Zn(II). By application of a computational chemistry method General Utility Lattice Program (GULP), it is demonstrated that the unique non-whole-number Na/P molar ratio of sodium ferric hydroxyphosphate is a consequence of its open-cage structure in which the H{sup +} and excess Na{sup +} ions are located.

  3. Transport of proteolipid protein to the plasma membrane does not depend on glycosphingolipid cotransport in oligodendrocyte cultures

    NARCIS (Netherlands)

    van der Haar, ME; Visser, HW; de Vries, H; Hoekstra, D

    1998-01-01

    The possibility that transport of proteolipid protein (PLP) from its site of synthesis to the plasma membrane is dependent on cotransport with (sulfo)galactocerebrosides was investigated in primary cultured oligodendrocytes and Chinese hamster ovary (CHO) cells expressing PLP. Sulfation was

  4. New aspects of cellular thallium uptake: Tl+-Na+-2Cl--cotransport is the central mechanism of ion uptake

    International Nuclear Information System (INIS)

    Sessler, M.J.; Maul, F.D.; Hoer, G.; Munz, D.L.; Geck, P.

    1986-01-01

    Cellular uptake mechanisms of 201 Tl + were studied in Ehrlich mouse ascites tumor cells. 201 Tl + phases the cell membrane of tumor cells using three transport systems: the ATPase, the Tl + -Na + -2Cl - -cotransport, and the Ca ++ -dependent ion channel. In the case of 201 Tl + the main route for entering the cells was the cotransport, its importance increasing with the age of the cells; in parallel, the ATPase activity was reduced. In contrast, the transport capacities of the ATPase and the cotransport were of the same magnitude in the case of 42 K + and 86 Rb + . This change in ion distribution was not brought about by varying velocity relations but by changing the number of transport systems in the cell membrane. There was no relationship between transport rates and diameters of the ions. 201 Tl + distribution is proportional to that of K + with a higher intracellular concentration of about 30%. Under physiological conditions the cotransport was reversible suggesting the ability to regulate steady state during varying extracellular ion concentrations. Cells and medium were two compartments, kinetically seen. Due to the significant difference of transport capacities between the three systems with the respective ions the term ''potassium-thallium-analogy'' may be misleading as it erroneously assumes identical uptake conditions. (orig.) [de

  5. Potassium co-transport and antiport during the uptake of sucrose and glutamic acid from the xylem vessels

    NARCIS (Netherlands)

    Bel, A.J.E. van; Erven, A.J. van

    Perfusion experiments with excised internodes of tomato (Lycopersicon esculentum cv Moneymaker) showed that the uptake of glutamic acid and sucrose from the xylem vessels is accompanied with coupled proton co-transport and potassium antiport at low pH (<5.5). At high pH (5.5) both proton and

  6. Lithium fluxes indicate presence of Na-Cl cotransport (NCC) in human lens epithelial cells.

    Science.gov (United States)

    Lauf, Peter K; Chimote, Ameet A; Adragna, Norma C

    2008-01-01

    During regulatory volume decrease (RVD) of human lens epithelial cells (hLECs) by clotrimazole (CTZ)-sensitive K fluxes, Na-K-2Cl cotransport (NKCC) remains active and K-Cl cotransport (KCC) inactive. To determine whether such an abnormal behavior was caused by RVD-induced cell shrinkage, NKCC was measured in the presence of either CTZ or in high K media to prevent RVD. NKCC transports RbCl + NaCl, and LiCl + KCl; thus ouabain-insensitive, bumetanide-sensitive (BS) or Cl-dependent (ClD) Rb and Li fluxes were determined in hyposmotic high NaCl media with CTZ, or in high KCl media alone, or with sulfamate (Sf) or nitrate as Cl replacement at varying Rb, Li or Cl mol fractions (MF). Unexpectedly, NKCC was inhibited by 80% with CTZ (IC(50) = 31 microM). In isosmotic (300 mOsM) K, Li influx was approximately 1/3 of Rb influx in Na, 50% lower in Sf, and bumetanide-insensitive (BI). In hypotonic (200 mOsM) K, only the ClD but not BS Li fluxes were detected. At Li MFs from 0.1-1, Li fluxes fitted a bell-shaped curve maxing at approximately 0.6 Li MF, with the BS fluxes equaling approximately 1/4 of the ClD-Li influx. The difference, i.e. the BI/ClD Li influx, saturated with increasing Li and Cl MFs, with K(ms) for Li of 11 with, and 7 mM without K, and of approximately 46 mM for Cl. Inhibition of this K-independent Li influx by thiazides was weak whilst furosemide (<100 microM) was ineffective. Reverse transcription polymerase chain reaction and Western blots verified presence of both NKCC1 and Na-Cl cotransport (NCC). In conclusion, in hyposmotic high K media, which prevents CTZ-sensitive K flux-mediated RVD in hLECs, NKCC1, though molecularly expressed, was functionally silent. However, a K-independent and moderately thiazide-sensitive ClD-Li flux, i.e. LiCC, likely occurring through NCC was detected operationally and molecularly. (c) 2008 S. Karger AG, Basel.

  7. [Sodium Glucose Co-transporter Type 2 (SGLT2) Inhibitors in CKD].

    Science.gov (United States)

    Insalaco, Monica; Zanoli, Luca; Rastelli, Stefania; Lentini, Paolo; Rapisarda, Francesco; Fatuzzo, Pasquale; Castellino, Pietro; Granata, Antonio

    2015-01-01

    Among the new drugs used for the treatment of Diabetes Mellitus type 2, sodium-glucose cotransporter 2 (SGLT2) inhibitors represent a promising therapeutic option. Since their ability to lower glucose is proportional to GFR, their effect is reduced in patients with chronic kidney disease (CKD). The antidiabetic mechanism of these drugs is insulin-independent and, therefore, complimentary to that of others antihyperglicaemic agents. Moreover, SGLT2 inhibitors are able to reduce glomerular hyperfiltration, systemic and intraglomerular pressure and uric acid levels, with consequent beneficial effects on the progression of kidney disease in non diabetic patients as well. Only few studies have been performed to evaluate the effects of SGLT2 inhibitors in patients with CKD. Therefore, safety and efficacy of SGLT2 inhibitors should be better clarified in the setting of CKD. In this paper, we will review the use of SGLT2 inhibitors in diabetic patients, including those with CKD.

  8. Sodium-glucose cotransporter 2 (SGLT-2) inhibitors for patients with Type 2 diabetes

    DEFF Research Database (Denmark)

    Røder, Michael Einar; Storgaard, Heidi; Rungby, Jørgen

    2016-01-01

    The sodium-glucose cotransporter 2 inhibitor (SGLT-2i)-class is efficacious as monotherapy and as add-on therapy with an expected lowering of the glycated haemoglobin (HbA1c) concentration of approximately 7 mmol/mol. Side effects relate to the mode of action, genital infections are the main...... problem. Extremely rare cases of ketoacidosis are reported, mostly in patients with Type 1 diabetes. One SGLT-2i, empagliflozin, has been shown to reduce cardiovascular mortality and progression of kidney disease in patients with Type 2 diabetes and cardiovascular disease. Outcome trials for other SGLT-2i...... are pending. SGLT-2i are now in guidelines as a possible second-line therapy or in case of metformin intolerance....

  9. Sodium-glucose cotransporter (SGLT)-2-inhibitorer til patienter med type 2-diabetes

    DEFF Research Database (Denmark)

    Røder, Michael Einar; Storgaard, Heidi; Rungby, Jørgen

    2016-01-01

    The sodium-glucose cotransporter 2 inhibitor (SGLT-2i)-class is efficacious as monotherapy and as add-on therapy with an expected lowering of the glycated haemoglobin (HbA1c) concentration of approximately 7 mmol/mol. Side effects relate to the mode of action, genital infections are the main...... problem. Extremely rare cases of ketoacidosis are reported, mostly in patients with Type 1 diabetes. One SGLT-2i, empagliflozin, has been shown to reduce cardiovascular mortality and progression of kidney disease in patients with Type 2 diabetes and cardiovascular disease. Outcome trials for other SGLT-2i...... are pending. SGLT-2i are now in guidelines as a possible second-line therapy or in case of metformin intolerance....

  10. A mathematical model of rat ascending Henle limb. I. Cotransporter function.

    Science.gov (United States)

    Weinstein, Alan M

    2010-03-01

    Kinetic models of Na+-K+-2Cl- costransporter (NKCC2) and K+-Cl- cotransporter (KCC4), two of the key cotransporters of the Henle limb, are fashioned with inclusion of terms representing binding and transport of NH4+. The models are simplified using assumptions of equilibrium ion binding, binding symmetry, and identity of Cl- binding sites. Model parameters are selected to be consistent with flux data from expression of these transporters in oocytes, specifically inwardly directed coupled transport of rubidium. In the analysis of these models, it is found that despite the simplifying assumptions to reduce the number of model parameters, neither model is uniquely determined by the data. For NKCC or KCC there are two- or three-parameter families of "optimal" solutions. As a consequence, one may specify several carrier translocation rates and/or ion affinities before fitting the remaining coefficients to the data, with no loss of fidelity in simulating the experiments. Model calculations suggest that with respect to NKCC2 near its operating point, the curve of ion flux as a function of cell Cl- is steep, and with respect to KCC4, its curve of ion flux as a function of peritubular K+ is also steep. The implication is that the kinetics are suitable for these two transporters in series to act as a sensor for peritubular K+, to modulate AHL Na+ reabsorption, with cytosolic Cl- as the intermediate variable. The models also reveal the potential for luminal NH4+ to be a potent catalyst for NKCC2 Na+ reabsorption, provided suitable exit mechanisms for NH4+ (from cell-to-lumen) are operative. It is found that KCC4 is likely to augment the secretory NH4+ flux, with peritubular NH4+ uptake driven by the cell-to-blood K+ gradient.

  11. Current view on the functional regulation of the neuronal K+-Cl- cotransporter KCC2

    Directory of Open Access Journals (Sweden)

    Igor eMedina

    2014-02-01

    Full Text Available In the mammalian central nervous system, the inhibitory strength of chloride (Cl--permeable GABAA and glycine receptors (GABAAR and GlyR depends on the intracellular Cl- concentration ([Cl-]i. Lowering [Cl-]i enhances inhibition, whereas raising [Cl-]i facilitates neuronal activity. A neuron’s basal level of [Cl-]i, as well as its Cl- extrusion capacity, is critically dependent on the activity of the electroneutral K+-Cl- cotransporter KCC2, a member of the SLC12 cation-Cl- cotransporter (CCC family. KCC2 deficiency compromises neuronal migration, formation and the maturation of GABAergic and glutamatergic synaptic connections, and results in network hyperexcitability and seizure activity. Several neurological disorders including multiple epilepsy subtypes, neuropathic pain, and schizophrenia, as well as various insults such as trauma and ischemia, are associated with significant decreases in the Cl- extrusion capacity of KCC2 that result in increases of [Cl-]i and the subsequent hyperexcitability of neuronal networks. Accordingly, identifying the key upstream molecular mediators governing the functional regulation of KCC2, and modifying these signalling pathways with small molecules, might constitute a novel neurotherapeutic strategy for multiple diseases. Here, we discuss recent advances in the understanding of the mechanisms regulating KCC2 activity, and of the role these mechanisms play in neuronal Cl- homeostasis and GABAergic neurotransmission. As KCC2 mediates electroneutral transport, the experimental recording of its activity constitutes an important research challenge; we therefore also, provide an overview of the different methodological approaches utilized to monitor function of KCC2 in both physiological and pathological conditions.

  12. Characterization of an extracellular epitope antibody to the neuronal K-Cl cotransporter, KCC2.

    Science.gov (United States)

    Gagnon, Kenneth Be; Fyffe, Robert Ew; Adragna, Norma C; Lauf, Peter K

    2007-07-01

    1. Ion gradients across the cell membrane are important for proper cellular communication and homeostasis. With the exception of erythrocytes, chloride (Cl), one of the most important free anions in animal cells, is not distributed at thermodynamic equilibrium across the plasma membrane. The K-Cl cotransporter (COT), consisting of at least four isoforms, utilizes the larger outwardly directed chemical driving force of K to expel Cl from the cell against its inwardly directed chemical gradient and has been implicated recently as one of the main Cl extruders in developing neurons. 2. Previous in situ hybridization studies have indicated widespread mRNA distribution of the neuronal-specific K-Cl COT isoform (KCC2) throughout the rat central nervous system (CNS). However, immunohistochemical studies have been limited owing to the availability of a more selective antibody to KCC2. The goal of the present study was to develop a new molecular tool for the immunohistochemical identification and neuronal distribution of KCC2. 3. Herein, we present evidence of immunohistochemical corroboration of the widespread KCC2 mRNA expression using a novel extracellular anti-peptide antibody directed against the second extracellular loop (ECL2) of KCC2. Immunoperoxidase and immunofluorescent labelling revealed widespread post-synaptic somatic and dendritic localization of KCC2 in multiple neuronal populations in the cerebral cortex, hippocampus, brainstem, lumbar spinal cord and cerebellum. We also demonstrate that binding of the antibody to an extracellular epitope within ECL2 does not alter cotransporter function. In essence, the present study reports on a new molecular tool for structural and functional studies of KCC2.

  13. Water transport by Na+-coupled cotransporters of glucose (SGLT1) and of iodide (NIS). The dependence of substrate size studied at high resolution

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Belhage, Bo; Zeuthen, Emil

    2005-01-01

    and osmosis at the membrane with diffusion in the cytoplasm. The combination of high resolution measurements and precise modelling showed that water transport across the membrane can be explained by cotransport of water in the membrane proteins and that intracellular unstirred layers effects are minute.......The relation between substrate and water transport was studied in Na+-coupled cotransporters of glucose (SGLT1) and of iodide (NIS) expressed in Xenopus oocytes. The water transport was monitored from changes in oocyte volume at a resolution of 20 pl, more than one order of magnitude better than...... previous investigations. The rate of cotransport was monitored as the clamp current obtained from two-electrode voltage clamp. The high resolution data demonstrated a fixed ratio between the turn-over of the cotransporter and the rate of water transport. This applied to experiments in which the rate...

  14. Use of 86Rb and 22Na in assaying active and cotransport activities in hum erythrocytes in a biracial population

    International Nuclear Information System (INIS)

    Sharma, C.; Dalferes, E.R. Jr; Freedman, D.S.; Asamoah, A.; Berenson, G.S.

    1988-01-01

    A defect in Na/sup +/-K/sup +/ transport across the red cell membrane has been shown to be associated with essential hypertension. A sensitive assay system to measure active, co- and countertransport systems in erythrocytes from normotensive adults was developed. Active, co- and countertransport systems in the erythrocytes were assayed by measuring the influx of radioactive /sup 22/Na/sup +/ and /sup 86/Rb/ sup +/. In the biracial (black-white) population group studied, analysis of variance of the active transport showed a significant race effect. Cotransport activity showed age by race interaction and age by sex. Cotransport activity was significantly higher in whites than blacks. The results suggest a subtle difference in Na/sup +/-K/sup +/ transport systems between blacks and whites, and these variations may be related to differences for susceptibility to essential hypertension

  15. Potassium channel and NKCC cotransporter involvement in ocular refractive control mechanisms.

    Directory of Open Access Journals (Sweden)

    Sheila G Crewther

    Full Text Available Myopia affects well over 30% of adult humans globally. However, the underlying physiological mechanism is little understood. This study tested the hypothesis that ocular growth and refractive compensation to optical defocus can be controlled by manipulation of potassium and chloride ion-driven transretinal fluid movements to the choroid. Chicks were raised with +/-10D or zero power optical defocus rendering the focal plane of the eye in front of, behind, or at the level of the retinal photoreceptors respectively. Intravitreal injections of barium chloride, a non-specific inhibitor of potassium channels in the retina and RPE or bumetanide, a selective inhibitor of the sodium-potassium-chloride cotransporter were made, targeting fluid control mechanisms. Comparison of refractive compensation to 5 mM Ba(2+ and 10(-5 M bumetanide compared with control saline injected eyes shows significant change for both positive and negative lens defocus for Ba(2+ but significant change only for negative lens defocus with bumetanide (Rx(SAL(-10D = -8.6 +/- .9 D; Rx(Ba2+(-10D = -2.9 +/- .9 D; Rx(Bum(-10D = -2.9 +/- .9 D; Rx(SAL(+10D = +8.2 +/- .9 D; Rx(Ba2+(+10D = +2.8 +/- 1.3 D; Rx(Bum(+10D = +8.0 +/- .7 D. Vitreous chamber depths showed a main effect for drug conditions with less depth change in response to defocus shown for Ba(2+ relative to Saline, while bumetanide injected eyes showed a trend to increased depth without a significant interaction with applied defocus. The results indicate that both K channels and the NKCC cotransporter play a role in refractive compensation with NKCC blockade showing far more specificity for negative, compared with positive, lens defocus. Probable sites of action relevant to refractive control include the apical retinal pigment epithelium membrane and the photoreceptor/ON bipolar synapse. The similarities between the biometric effects of NKCC inhibition and biometric reports of the blockade of the retinal ON response, suggest a

  16. Clinical potential of sodium-glucose cotransporter 2 inhibitors in the management of type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Kim Y

    2012-08-01

    Full Text Available Yoojin Kim, Ambika R BabuDivision of Endocrinology, John Stroger Jr Hospital of Cook County and Rush University, Chicago, IL, USABackground: The kidney plays an important role in glucose metabolism, and has been considered a target for therapeutic intervention. The sodium-glucose cotransporter type 2 (SGLT2 mediates most of the glucose reabsorption from the proximal renal tubule. Inhibition of SGLT2 leads to glucosuria and provides a unique mechanism to lower elevated blood glucose levels in diabetes. The purpose of this review is to explore the physiology of SGLT2 and discuss several SGLT2 inhibitors which have clinical data in patients with type 2 diabetes.Methods: We performed a PubMed search using the terms "SGLT2" and "SGLT2 inhibitor" through April 10, 2012. Published articles, press releases, and abstracts presented at national and international meetings were considered.Results: SGLT2 inhibitors correct a novel pathophysiological defect, have an insulin-independent action, are efficacious with glycosylated hemoglobin reduction ranging from 0.5% to 1.5%, promote weight loss, have a low incidence of hypoglycemia, complement the action of other antidiabetic agents, and can be used at any stage of diabetes. They are generally well tolerated. However, due to side effects, such as repeated urinary tract and genital infections, increased hematocrit, and decreased blood pressure, appropriate patient selection for drug initiation and close monitoring after initiation will be important. Results of ongoing clinical studies of the effect of SGLT2 inhibitors on diabetic complications and cardiovascular safety are crucial to determine the risk-benefit ratio. A recent decision by the Committee for Medicinal Products for Human Use of the European Medicines Agency has recommended approval of dapagliflozin for the treatment of type 2 diabetes as an adjunct to diet and exercise, in combination with other glucose-lowering medicinal products, including

  17. Sodium-glucose cotransporter 2 inhibitors with insulin in type 2 diabetes: Clinical perspectives

    Directory of Open Access Journals (Sweden)

    Mathew John

    2016-01-01

    Full Text Available The treatment of type 2 diabetes is a challenging problem. Most subjects with type 2 diabetes have progression of beta cell failure necessitating the addition of multiple antidiabetic agents and eventually use of insulin. Intensification of insulin leads to weight gain and increased risk of hypoglycemia. Sodium-glucose cotransporter 2 (SGLT2 inhibitors are a class of antihyperglycemic agents which act by blocking the SGLT2 in the proximal tubule of the kidney. They have potential benefits in terms of weight loss and reduction of blood pressure in addition to improvements in glycemic control. Further, one of the SGLT2 inhibitors, empagliflozin has proven benefits in reducing adverse cardiovascular (CV outcomes in a CV outcome trial. Adding SGLT2 inhibitors to insulin in subjects with type 2 diabetes produced favorable effects on glycemic control without the weight gain and hypoglycemic risks associated with insulin therapy. The general risks of increased genital mycotic infections, urinary tract infections, volume, and osmosis-related adverse effects in these subjects were similar to the pooled data of individual SGLT2 inhibitors. There are subsets of subjects with type 2 diabetes who may have insulin deficiency, beta cell autoimmunity, or is prone to diabetic ketoacidosis. In these subjects, SGLT2 inhibitors should be used with caution to prevent the rare risks of ketoacidosis.

  18. Lowering Plasma Glucose Concentration by Inhibiting Renal Sodium-Glucose Co-Transport

    Science.gov (United States)

    Abdul-Ghani, Muhammad A; DeFronzo, Ralph A

    2017-01-01

    Maintaining normoglycaemia not only reduces the risk of diabetic microvascular complications but also corrects the metabolic abnormalities that contribute to the development and progression of hyperglycaemia (i.e. insulin resistance and beta-cell dysfunction). Progressive beta-cell failure, in addition to the multiple side effects associated with many current antihyperglycaemic agents (e.g., hypoglycaemia and weight gain) presents major obstacle to the achievement of the recommended goal of glycaemic control in patients with diabetes mellitus (DM). Thus, novel effective therapies are needed for optimal glucose control in subjects with DM. Recently, specific inhibitors of renal sodium glucose cotransporter 2 (SGLT2) have been developed to produce glucosuria and lower the plasma glucose concentration. Because of their unique mechanism of action (which is independent of the secretion and action of insulin), these agents are effective in lowering the plasma glucose concentration in all stages of DM and can be combined with all other antidiabetic agents. In this review, we summarize the available data concerning the mechanism of action, efficacy and safety of this novel class of antidiabetic agent. PMID:24690096

  19. Sodium glucose co-transporter 2 (SGLT2) inhibitors: novel antidiabetic agents.

    Science.gov (United States)

    Washburn, William N

    2012-05-01

    Maintenance of glucose homeostasis in healthy individuals involves SGLT2 (sodium glucose co-transporter 2)-mediated recovery of glucose from the glomerular filtrate which otherwise would be excreted in urine. Clinical studies indicate that SGLT2 inhibitors provide an insulin-independent means to reduce the hyperglycemia that is the hallmark of type 2 diabetes mellitus (T2DM) with minimal risk of hypoglycemia. The pharmacophore common to the SGLT2 inhibitors currently in development is a diarylmethane C-glucoside which is discussed in this review. The focus is how this pharmacophore was further modified as inferred from the patents publishing from 2009 to 2011. The emphasis is on the strategy that each group employed to circumvent the constraints imposed by prior art and how the resulting SGLT2 potency and selectivity versus SGLT1 compared with that of the lead clinical compound dapagliflozin. SGLT2 inhibitors offer a new fundamentally different approach for treatment of diabetes. To date, the clinical results suggest that for non-renally impaired patients this class of inhibitors could be safely used at any stage of T2DM either alone or in combination with other marketed antidiabetic medications.

  20. Differential cardiovascular profiles of sodium-glucose cotransporter 2 inhibitors: critical evaluation of empagliflozin

    Directory of Open Access Journals (Sweden)

    Sanon VP

    2017-05-01

    Full Text Available Vani P Sanon,1 Shalin Patel,1 Saurabh Sanon,2 Ruben Rodriguez,1 Son V Pham,1 Robert Chilton1 1Division of Cardiology, University of Texas Health Science Center at San Antonio, Audie L Murphy VA Hospital, San Antonio, TX, 2Interventional Cardiology-Structural Heart Disease, Cardiology Consultants at Baptist Heart and Vascular Institute, Pensacola, FL, USA Abstract: One of the most feared repercussions of type 2 diabetes mellitus is the risk of adverse cardiovascular outcomes. The current antidiabetic agents on the market have had difficulty in showing cardiovascular outcome improvement. The EMPA-REG OUTCOME trial studied the sodium-glucose cotransporter 2 inhibitor empagliflozin in type 2 diabetic patients at high risk of cardiovascular events. The trial results revealed a decrease in the composite primary end points of death from cardiovascular causes, nonfatal myocardial infarction, and nonfatal stroke in those taking empagliflozin vs placebo. Those taking the medication also had a significant decrease in death from any cause, death from cardiovascular cause, and hospitalization for heart failure. The EMPA-REG trial is paradigm shifting because it demonstrates a clear mortality benefit to cardiovascular outcomes with a low side-effect profile, in contrast to prior outcome studies of hypoglycemic agents. Further studies are required to better clarify the long-term safety and efficacy of this promising class of diabetic drugs. Keywords: SGLT2 inhibitors, diabetes, cardiovascular mortality, heart failure, hypertension

  1. Renal sodium-glucose cotransporter inhibition in the management of type 2 diabetes mellitus

    Science.gov (United States)

    Abdul-Ghani, Muhammad A.; Norton, Luke

    2015-01-01

    Hyperglycemia is the primary factor responsible for the microvascular, and to a lesser extent macrovascular, complications of diabetes. Despite this well-established relationship, approximately half of all type 2 diabetic patients in the US have a hemoglobin A1c (HbA1c) ≥7.0%. This is associated in part with the side effects, i.e., weight gain and hypoglycemia, of currently available antidiabetic agents and in part with the failure to utilize medications that reverse the basic pathophysiological defects present in patients with type 2 diabetes. The kidney has been shown to play a central role in the development of hyperglycemia by excessive production of glucose throughout the sleeping hours and enhanced reabsorption of filtered glucose by the renal tubules secondary to an increase in the threshold at which glucose spills into the urine. Recently, a new class of antidiabetic agents, the sodium-glucose cotransporter 2 (SGLT2) inhibitors, has been developed and approved for the treatment of patients with type 2 diabetes. In this review, we examine their mechanism of action, efficacy, safety, and place in the therapeutic armamentarium. Since the SGLT2 inhibitors have a unique mode of action that differs from all other oral and injectable antidiabetic agents, they can be used at all stages of the disease and in combination with all other antidiabetic medications. PMID:26354881

  2. A specific pharmacophore model of sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors.

    Science.gov (United States)

    Tang, Chunlei; Zhu, Xiaoyun; Huang, Dandan; Zan, Xin; Yang, Baowei; Li, Ying; Du, Xiaoyong; Qian, Hai; Huang, Wenlong

    2012-06-01

    Sodium-dependent glucose co-transporter 2 (SGLT2) plays a pivotal role in maintaining glucose equilibrium in the human body, emerging as one of the most promising targets for the treatment of diabetes mellitus type 2. Pharmacophore models of SGLT2 inhibitors have been generated with a training set of 25 SGLT2 inhibitors using Discovery Studio V2.1. The best hypothesis (Hypo1(SGLT2)) contains one hydrogen bond donor, five excluded volumes, one ring aromatic and three hydrophobic features, and has a correlation coefficient of 0.955, cost difference of 68.76, RMSD of 0.85. This model was validated by test set, Fischer randomization test and decoy set methods. The specificity of Hypo1(SGLT2) was evaluated. The pharmacophore features of Hypo1(SGLT2) were different from the best pharmacophore model (Hypo1(SGLT1)) of SGLT1 inhibitors we developed. Moreover, Hypo1(SGLT2) could effectively distinguish selective inhibitors of SGLT2 from those of SGLT1. These results indicate that a highly predictive and specific pharmacophore model of SGLT2 inhibitors has been successfully obtained. Then Hypo1(SGLT2) was used as a 3D query to screen databases including NCI and Maybridge for identifying new inhibitors of SGLT2. The hit compounds were subsequently subjected to filtering by Lipinski's rule of five. And several compounds selected from the top ranked hits have been suggested for further experimental assay studies.

  3. Characterization and comparison of sodium-glucose cotransporter 2 inhibitors in pharmacokinetics, pharmacodynamics, and pharmacologic effects

    Directory of Open Access Journals (Sweden)

    Atsuo Tahara

    2016-03-01

    Full Text Available The sodium-glucose cotransporter (SGLT 2 offer a novel approach to treating type 2 diabetes by reducing hyperglycaemia via increased urinary glucose excretion. In the present study, the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six SGLT2 inhibitors commercially available in Japan were investigated and compared. Based on findings in normal and diabetic mice, the six drugs were classified into two categories, long-acting: ipragliflozin and dapagliflozin, and intermediate-acting: tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin. Long-acting SGLT2 inhibitors exerted an antihyperglycemic effect with lower variability of blood glucose level via a long-lasting increase in urinary glucose excretion. In addition, ipragliflozin and luseogliflozin exhibited superiority over the others with respect to fast onset of pharmacological effect. Duration and onset of the pharmacologic effects seemed to be closely correlated with the pharmacokinetic properties of each SGLT2 inhibitor, particularly with respect to high distribution and long retention in the target organ, the kidney. While all six SGLT2 inhibitors were significantly effective in increasing urinary glucose excretion and reducing hyperglycemia, our findings suggest that variation in the quality of daily blood glucose control associated with duration and onset of pharmacologic effects of each SGLT2 inhibitor might cause slight differences in rates of improvement in type 2 diabetes.

  4. Sodium glucose CoTransporter 2 (SGLT2) inhibitors: Current status and future perspective.

    Science.gov (United States)

    Madaan, Tushar; Akhtar, Mohd; Najmi, Abul Kalam

    2016-10-10

    Diabetes mellitus is a disease that affects millions of people worldwide and its prevalence is estimated to rise in the future. Billions of dollars are spent each year around the world in health expenditure related to diabetes. There are several anti-diabetic drugs in the market for the treatment of non-insulin dependent diabetes mellitus. In this article, we will be talking about a relatively new class of anti-diabetic drugs called sodium glucose co-transporter 2 (SGLT2) inhibitors. This class of drugs has a unique mechanism of action focusing on inhibition of glucose reabsorption that separates it from other classes. This article covers the mechanism of glucose reabsorption in the kidneys, the mechanism of action of SGLT2 inhibitors, several SGLT2 inhibitors currently available in the market as well as those in various phases of development, their individual pharmacokinetics as well as the discussion about the future role of SGLT2 inhibitors, not only for the treatment of diabetes, but also for various other diseases like obesity, hepatic steatosis, and cardiovascular disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Potassium Supplementation Prevents Sodium Chloride Cotransporter Stimulation During Angiotensin II Hypertension.

    Science.gov (United States)

    Veiras, Luciana C; Han, Jiyang; Ralph, Donna L; McDonough, Alicia A

    2016-10-01

    Angiotensin II (AngII) hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na(+) channel abundance and activating cleavage. Acutely raising plasma [K(+)] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K(+)] with a single 3-hour 2% potassium meal would lower NCCp in Sprague-Dawley rats after 14 days of AngII (400 ng/kg per minute). The potassium-rich meal neither decreased NCCp nor increased K(+) excretion. AngII-infused rats exhibited lower plasma [K(+)] versus controls (3.6±0.2 versus 4.5±0.1 mmol/L; Pblood pressure did not significantly decrease. Epithelial Na(+) channel subunit abundance and cleavage increased 1.5- to 3-fold in both A1K and A2K; ROMK (renal outer medulla K(+) channel abundance) abundance was unaffected by AngII or dietary K(+) In summary, the accumulation and phosphorylation of NCC seen during chronic AngII infusion hypertension is likely secondary to potassium deficiency driven by epithelial Na(+) channel stimulation. © 2016 American Heart Association, Inc.

  6. Renal glucose handling in diabetes and sodium glucose cotransporter 2 inhibition

    Directory of Open Access Journals (Sweden)

    Resham Raj Poudel

    2013-01-01

    Full Text Available The kidneys play a major role in glucose homeostasis through its utilization, gluconeogenesis, and reabsorption via sodium glucose cotransporters (SGLTs. The defective renal glucose handling from upregulation of SGLTs, mainly the SGLT2, plays a fundamental role in the pathogenesis of type 2 diabetes mellitus. Genetic mutations in a SGLT2 isoform that results in benign renal glycosuria, as well as clinical studies with SGLT2 inhibitors in type 2 diabetes support the potential of this approach. These studies indicate that inducing glycosuria by suppressing SGLT2 can reduce plasma glucose and A1c levels, as well as decrease weight, resulting in improved β-cell function and enhanced insulin sensitivity in liver and muscle. Because the mechanism of SGLT2 inhibition is independent of insulin secretion and sensitivity, these agents can be combined with other antidiabetic agents, including exogenous insulin. This class represents a novel therapeutic approach with potential for the treatment of both type 2 and type 1 diabetes.

  7. Relevance of sodium/glucose cotransporter-1 (SGLT1) to diabetes mellitus and obesity in dogs.

    Science.gov (United States)

    Batchelor, D J; German, A J; Shirazi-Beechey, S P

    2013-04-01

    Glucose transport across the enterocyte brush border membrane by sodium/glucose cotransporter-1 (SGLT1, coded by Slc5a1) is the rate-limiting step for intestinal glucose transport. The relevance of SGLT1 expression in predisposition to diabetes mellitus and to obesity was investigated in dogs. Cultured Caco-2/TC7 cells were shown to express SGLT1 in vitro. A 2-kbp fragment of the Slc5a1 5' flanking region was cloned from canine genomic DNA, ligated into reporter gene plasmids, and shown to drive reporter gene expression in these cells above control (P obesity (Labrador retriever and cocker spaniel). The Slc5a1 5' flanking region was amplified from 10 healthy individuals of each of these breeds by high-fidelity PCR with the use of breed-labeled primers and sequenced by pyrosequencing. The sequence of the Slc5a1 5' flanking region in all individuals of all breeds tested was identical. On this evidence, variations in Slc5a1 promoter sequence between dogs do not influence the pathogenesis of diabetes mellitus or obesity in these breeds. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Sodium-glucose co-transporter-2 inhibitors and euglycemic ketoacidosis: Wisdom of hindsight

    Directory of Open Access Journals (Sweden)

    Awadhesh Kumar Singh

    2015-01-01

    Full Text Available Sodium-glucose co-transporter-2 inhibitors (SGLT-2i are newly approved class of oral anti-diabetic drugs, in the treatment of type 2 diabetes, which reduces blood glucose through glucouresis via the kidney, independent, and irrespective of available pancreatic beta-cells. Studies conducted across their clinical development program found, a modest reduction in glycated hemoglobin ranging from −0.5 to −0.8%, without any significant hypoglycemia. Moreover, head-to-head studies versus active comparators yielded comparable efficacy. Interestingly, weight and blood pressure reduction were additionally observed, which was not only consistent but significantly superior to active comparators, including metformin, sulfonylureas, and dipeptydylpeptide-4 inhibitors. Indeed, these additional properties makes this class a promising oral anti-diabetic drug. Surprisingly, a potentially fatal unwanted side effect of diabetic ketoacidosis has been noted with its widespread use, albeit rarely. Nevertheless, this has created a passé among the clinicians. This review is an attempt to pool those ketosis data emerging with SGLT-2i, and put a perspective on its implicated mechanism.

  9. Evidence for a specific glutamate/H+ cotransport in isolated mesophyll cells

    International Nuclear Information System (INIS)

    McCutcheon, S.L.; Bown, A.W.

    1987-01-01

    Mechanically isolated Asparagus sprengeri Regel mesophyll cells were suspended in 1 millimolar CaSO 4 . Immediate alkalinization of the medium occurred on the addition of 1 millimolar concentrations of L-glutamate (Glu) and its analog L-methionine-D,L-sulfoximine (L-MSO). D-Glu and the L isomers of the protein amino acids did not elicit alkalinization. L-Glu dependent alkalinization was transient and acidification resumed after approximately 30 to 45 minutes. At pH 6.0, 5 millimolar L-Glu stimulated initial rates of alkalinization that varied between 1.3 to 4.1 nmol H + /10 6 cells minute. L-Glu dependent alkalinization was saturable, increased with decreasing pH, was inhibited by carbonyl cyanide-p-trichloromethoxyphenyl hydrazone (CCCP), and was not stimulated by light. Uptake of L-[U- 14 C]glutamate increased as the pH decreased from 6.5 to 5.5, and was inhibited by L-MSO. L-Glu had no influence on K + efflux. Although evidence for multiple amino acid/proton cotransport systems has been found in other tissues, the present report indicates that a highly specific L-Glu/proton uptake process is present in Asparagus mesophyll cells

  10. Abnormal expression of cerebrospinal fluid cation chloride cotransporters in patients with Rett syndrome.

    Directory of Open Access Journals (Sweden)

    Sofia Temudo Duarte

    Full Text Available OBJECTIVE: Rett Syndrome is a progressive neurodevelopmental disorder caused mainly by mutations in the gene encoding methyl-CpG-binding protein 2. The relevance of MeCP2 for GABAergic function was previously documented in animal models. In these models, animals show deficits in brain-derived neurotrophic factor, which is thought to contribute to the pathogenesis of this disease. Neuronal Cation Chloride Cotransporters (CCCs play a key role in GABAergic neuronal maturation, and brain-derived neurotrophic factor is implicated in the regulation of CCCs expression during development. Our aim was to analyse the expression of two relevant CCCs, NKCC1 and KCC2, in the cerebrospinal fluid of Rett syndrome patients and compare it with a normal control group. METHODS: The presence of bumetanide sensitive NKCC1 and KCC2 was analysed in cerebrospinal fluid samples from a control pediatric population (1 day to 14 years of life and from Rett syndrome patients (2 to 19 years of life, by immunoblot analysis. RESULTS: Both proteins were detected in the cerebrospinal fluid and their levels are higher in the early postnatal period. However, Rett syndrome patients showed significantly reduced levels of KCC2 and KCC2/NKCC1 ratio when compared to the control group. CONCLUSIONS: Reduced KCC2/NKCC1 ratio in the cerebrospinal fluid of Rett Syndrome patients suggests a disturbed process of GABAergic neuronal maturation and open up a new therapeutic perspective.

  11. The plant homolog to the human sodium/dicarboxylic cotransporter is the vacuolar malate carrier.

    Science.gov (United States)

    Emmerlich, Vera; Linka, Nicole; Reinhold, Thomas; Hurth, Marco A; Traub, Michaela; Martinoia, Enrico; Neuhaus, H Ekkehard

    2003-09-16

    Malate plays a central role in plant metabolism. It is an intermediate in the Krebs and glyoxylate cycles, it is the store for CO2 in C4 and crassulacean acid metabolism plants, it protects plants from aluminum toxicity, it is essential for maintaining the osmotic pressure and charge balance, and it is therefore involved in regulation of stomatal aperture. To fulfil many of these roles, malate has to be accumulated within the large central vacuole. Many unsuccessful efforts have been made in the past to identify the vacuolar malate transporter; here, we describe the identification of the vacuolar malate transporter [A. thaliana tonoplast dicarboxylate transporter (AttDT)]. This transporter exhibits highest sequence similarity to the human sodium/dicarboxylate cotransporter. Independent T-DNA [portion of the Ti (tumor-inducing) plasmid that is transferred to plant cells] Arabidopsis mutants exhibit substantially reduced levels of leaf malate, but respire exogenously applied [14C]malate faster than the WT. An AttDT-GFP fusion protein was localized to vacuole. Vacuoles isolated from Arabidopsis WT leaves exhibited carbonylcyanide m-chlorophenylhydrazone and citrate inhibitable malate transport, which was not stimulated by sodium. Vacuoles isolated from mutant plants import [14C]-malate at strongly reduced rates, confirming that this protein is the vacuolar malate transporter.

  12. Vasopressin alters the mechanism of apical Cl- entry from Na+:Cl- to Na+:K+:2Cl- cotransport in mouse medullary thick ascending limb

    Energy Technology Data Exchange (ETDEWEB)

    Sun, A.; Grossman, E.B.; Lombardi, M.; Hebert, S.C. (Brigham and Women' s Hospital, Boston, MA (USA))

    1991-02-01

    Experiments were performed using in vitro perfused medullary thick ascending limbs of Henle (MTAL) and in suspensions of MTAL tubules isolated from mouse kidney to evaluate the effects of arginine vasopressin (AVP) on the K+ dependence of the apical, furosemide-sensitive Na{sup +}:Cl{sup {minus}} cotransporter and on transport-related oxygen consumption (QO{sub 2}). In isolated perfused MTAL segments, the rate of cell swelling induced by removing K+ from, and adding one mM ouabain to, the basolateral solution (ouabain(zero-K+)) provided an index to apical cotransporter activity and was used to evaluate the ionic requirements of the apical cotransporter in the presence and absence of AVP. In the absence of AVP cotransporter activity required Na{sup +} and Cl{sup {minus}}, but not K{sup +}, while the presence of AVP the apical cotransporter required all three ions. {sup 86}Rb{sup +} uptake into MTAL tubules in suspension was significant only after exposure of tubules to AVP. Moreover, {sup 22}Na{sup +} uptake was unaffected by extracellular K+ in the absence of AVP while after AVP exposure {sup 22}Na{sup +} uptake was strictly K{sup +}-dependent. The AVP-induced coupling of K{sup +} to the Na{sup +}:Cl{sup {minus}} cotransporter resulted in a doubling in the rate of NaCl absorption without a parallel increase in the rate of cellular {sup 22}Na{sup +} uptake or transport-related oxygen consumption. These results indicate that arginine vasopressin alters the mode of a loop diuretic-sensitive transporter from Na{sup +}:Cl{sup {minus}} cotransport to Na{sup +}:K{sup +}:2Cl{sup {minus}} cotransport in the mouse MTAL with the latter providing a distinct metabolic advantage for sodium transport. A model for AVP action on NaCl absorption by the MTAL is presented and the physiological significance of the coupling of K{sup +} to the apical Na{sup +}:Cl{sup {minus}} cotransporter in the MTAL and of the enhanced metabolic efficiency are discussed.

  13. Sodium glucose co-transporter 2 (SGLT2) inhibitors: new among antidiabetic drugs.

    Science.gov (United States)

    Opie, L H

    2014-08-01

    Type 2 diabetes is characterized by decreased insulin secretion and sensitivity. The available oral anti-diabetic drugs act on many different molecular sites. The most used of oral anti-diabetic agents is metformin that activates glucose transport vesicles to the cell surface. Others are: the sulphonylureas; agents acting on the incretin system; GLP-1 agonists; dipetidylpeptidase-4 inhibitors; meglinitide analogues; and the thiazolidinediones. Despite these many drugs acting by different mechanisms, glycaemic control often remains elusive. None of these drugs have a primary renal mechanism of action on the kidneys, where almost all glucose excreted is normally reabsorbed. That is where the inhibitors of glucose reuptake (sodium-glucose cotransporter 2, SGLT2) have a unique site of action. Promotion of urinary loss of glucose by SGLT2 inhibitors embodies a new principle of control in type 2 diabetes that has several advantages with some urogenital side-effects, both of which are evaluated in this review. Specific approvals include use as monotherapy, when diet and exercise alone do not provide adequate glycaemic control in patients for whom the use of metformin is considered inappropriate due to intolerance or contraindications, or as add-on therapy with other anti-hyperglycaemic medicinal products including insulin, when these together with diet and exercise, do not provide adequate glycemic control. The basic mechanisms are improved β-cell function and insulin sensitivity. When compared with sulphonylureas or other oral antidiabetic agents, SGLT2 inhibitors provide greater HbA1c reduction. Urogenital side-effects related to the enhanced glycosuria can be troublesome, yet seldom lead to discontinuation. On this background, studies are analysed that compare SGLT2 inhibitors with other oral antidiabetic agents. Their unique mode of action, unloading the excess glycaemic load, contrasts with other oral agents that all act to counter the effects of diabetic

  14. Blood pressure effects of sodium-glucose co-transport 2 (SGLT2) inhibitors.

    Science.gov (United States)

    Oliva, Raymond V; Bakris, George L

    2014-05-01

    Management of hypertension in diabetes is critical for reduction of cardiovascular mortality and morbidity. While blood pressure (BP) control has improved over the past two decades, the control rate is still well below 50% in the general population of patients with type 2 diabetes mellitus (T2DM). A new class of oral glucose-lowering agents has recently been approved; the sodium-glucose co-transporter 2 (SGLT2) inhibitors, which act by eliminating large amounts of glucose in the urine. Two agents, dapagliflozin and canagliflozin, are currently approved in the United States and Europe, and empagliflozin and ipragliflozin have reported Phase 3 trials. In addition to glucose lowering, SGLT2 inhibitors are associated with weight loss and act as osmotic diuretics, resulting in a lowering of BP. While not approved for BP-lowering, they may potentially aid BP goal achievement in people within 7-10 mm Hg of goal. It should be noted that the currently approved agents have side effects that include an increased incidence of genital infections, predominantly in women. The approved SGLT2 inhibitors have limited use based on kidney function and should be used only in those with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2 for dapagliflozin and ≥45 mL/min/1.73 m2 for canagliflozin. Cardiovascular outcome trials are ongoing with these agents and will be completed within the next 4-5 years. Copyright © 2014 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  15. Natural Products as Lead Compounds for Sodium Glucose Cotransporter (SGLT) Inhibitors.

    Science.gov (United States)

    Blaschek, Wolfgang

    2017-08-01

    Glucose homeostasis is maintained by antagonistic hormones such as insulin and glucagon as well as by regulation of glucose absorption, gluconeogenesis, biosynthesis and mobilization of glycogen, glucose consumption in all tissues and glomerular filtration, and reabsorption of glucose in the kidneys. Glucose enters or leaves cells mainly with the help of two membrane integrated transporters belonging either to the family of facilitative glucose transporters (GLUTs) or to the family of sodium glucose cotransporters (SGLTs). The intestinal glucose absorption by endothelial cells is managed by SGLT1, the transfer from them to the blood by GLUT2. In the kidney SGLT2 and SGLT1 are responsible for reabsorption of filtered glucose from the primary urine, and GLUT2 and GLUT1 enable the transport of glucose from epithelial cells back into the blood stream.The flavonoid phlorizin was isolated from the bark of apple trees and shown to cause glucosuria. Phlorizin is an inhibitor of SGLT1 and SGLT2. With phlorizin as lead compound, specific inhibitors of SGLT2 were developed in the last decade and some of them have been approved for treatment mainly of type 2 diabetes. Inhibition of SGLT2 eliminates excess glucose via the urine. In recent times, the dual SGLT1/SGLT2 inhibitory activity of phlorizin has served as a model for the development and testing of new drugs exhibiting both activities.Besides phlorizin, also some other flavonoids and especially flavonoid enriched plant extracts have been investigated for their potency to reduce postprandial blood glucose levels which can be helpful in the prevention and supplementary treatment especially of type 2 diabetes. Georg Thieme Verlag KG Stuttgart · New York.

  16. Nonclinical safety of the sodium-glucose cotransporter 2 inhibitor empagliflozin.

    Science.gov (United States)

    Bogdanffy, Matthew S; Stachlewitz, Robert F; van Tongeren, Susan; Knight, Brian; Sharp, Dale E; Ku, Warren; Hart, Susan Emeigh; Blanchard, Kerry

    2014-01-01

    Empagliflozin, a selective inhibitor of the renal tubular sodium-glucose cotransporter 2, was developed for treatment of type 2 diabetes mellitus. Nonclinical safety of empagliflozin was studied in a battery of tests to support global market authorization. Safety pharmacology studies indicated no effect of empagliflozin on measures of respiratory or central nervous system function in rats or cardiovascular safety in telemeterized dogs. In CD-1 mouse, Wistar Han rat, or beagle dogs up to 13, 26, or 52 weeks of treatment, respectively, empagliflozin exhibited a toxicity profile consistent with secondary supratherapeutic pharmacology related to glucose loss and included decreased body weight and body fat, increased food consumption, diarrhea, dehydration, decreased serum glucose and increases in other serum parameters reflective of increased protein catabolism, gluconeogenesis, and electrolyte imbalances, and urinary changes such as polyuria and glucosuria. Microscopic changes were consistently observed in kidney and included tubular nephropathy and interstitial nephritis (dog), renal mineralization (rat) and tubular epithelial cell karyomegaly, single cell necrosis, cystic hyperplasia, and hypertrophy (mouse). Empagliflozin was not genotoxic. Empagliflozin was not carcinogenic in female mice or female rats. Renal adenoma and carcinoma were induced in male mice only at exposures 45 times the maximum clinical dose. These tumors were associated with a spectrum of nonneoplastic changes suggestive of a nongenotoxic, cytotoxic, and cellular proliferation-driven mechanism. In male rats, testicular interstitial cell tumors and hemangiomas of the mesenteric lymph node were observed; both tumors are common in rats and are unlikely to be relevant to humans. These studies demonstrate the nonclinical safety of empagliflozin. © The Author(s) 2014.

  17. Experimental investigation of virus and clay particles cotransport in partially saturated columns packed with glass beads.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2015-02-15

    Suspended clay particles in groundwater can play a significant role as carriers of viruses, because, depending on the physicochemical conditions, clay particles may facilitate or hinder the mobility of viruses. This experimental study examines the effects of clay colloids on the transport of viruses in variably saturated porous media. All cotransport experiments were conducted in both saturated and partially saturated columns packed with glass beads, using bacteriophages MS2 and ΦX174 as model viruses, and kaolinite (KGa-1b) and montmorillonite (STx-1b) as model clay colloids. The various experimental collision efficiencies were determined using the classical colloid filtration theory. The experimental data indicated that the mass recovery of viruses and clay colloids decreased as the water saturation decreased. Temporal moments of the various breakthrough concentrations collected, suggested that the presence of clays significantly influenced virus transport and irreversible deposition onto glass beads. The mass recovery of both viruses, based on total effluent virus concentrations, was shown to reduce in the presence of suspended clay particles. Furthermore, the transport of suspended virus and clay-virus particles was retarded, compared to the conservative tracer. Under unsaturated conditions both clay particles facilitated the transport of ΦX174, while hindered the transport of MS2. Moreover, the surface properties of viruses, clays and glass beads were employed for the construction of classical DLVO and capillary potential energy profiles, and the results suggested that capillary forces play a significant role on colloid retention. It was estimated that the capillary potential energy of MS2 is lower than that of ΦX174, and the capillary potential energy of KGa-1b is lower than that of STx-1b, assuming that the protrusion distance through the water film is the same for each pair of particles. Moreover, the capillary potential energy is several orders of

  18. Modulation of the cardiac sodium/bicarbonate cotransporter by the renin angiotensin aldosterone system: pathophysiological consequences.

    Science.gov (United States)

    De Giusti, Verónica C; Ciancio, María C; Orlowski, Alejandro; Aiello, Ernesto A

    2013-01-01

    The sodium/bicarbonate cotransporter (NBC) is one of the major alkalinizing mechanisms in the cardiomyocytes. It has been demonstrated the existence of at least two functional isoforms, one that promotes the co-influx of 1 molecule of Na(+) per 1 molecule of HCO(-) 3 (electroneutral isoform; NBCn1) and the other one that generates the co-influx of 1 molecule of Na(+) per 2 molecules of HCO(-) 3 (electrogenic isoform; NBCe1). Both isoforms are important to maintain intracellular pH (pH i ) and sodium concentration ([Na(+)] i ). In addition, NBCe1 generates an anionic repolarizing current that modulates the action potential duration (APD). The renin-angiotensin-aldosterone system (RAAS) is implicated in the modulation of almost all physiological cardiac functions and is also involved in the development and progression of cardiac diseases. It was reported that angiotensin II (Ang II) exhibits an opposite effect on NBC isoforms: it activates NBCn1 and inhibits NBCe1. The activation of NBCn1 leads to an increase in pH i and [Na(+)] i , which indirectly, due to the stimulation of reverse mode of the Na(+)/Ca(2+) exchanger (NCX), conduces to an increase in the intracellular Ca(2+) concentration. On the other hand, the inhibition of NBCe1 generates an APD prolongation, potentially representing a risk of arrhythmias. In the last years, the potentially altered NBC function in pathological scenarios, as cardiac hypertrophy and ischemia-reperfusion, has raised increasing interest among investigators. This review attempts to draw the attention on the relevant regulation of NBC activity by RAAS, since it modulates pH i and [Na(+)] i , which are involved in the development of cardiac hypertrophy, the damage produced by ischemia-reperfusion and the generation of arrhythmic events, suggesting a potential role of NBC in cardiac diseases.

  19. Salt sensitivity of blood pressure is associated with polymorphisms in the sodium-bicarbonate cotransporter.

    Science.gov (United States)

    Carey, Robert M; Schoeffel, Cynthia D; Gildea, John J; Jones, John E; McGrath, Helen E; Gordon, Lindsay N; Park, Min Jeong; Sobota, Rafal S; Underwood, Patricia C; Williams, Jonathan; Sun, Bei; Raby, Benjamin; Lasky-Su, Jessica; Hopkins, Paul N; Adler, Gail K; Williams, Scott M; Jose, Pedro A; Felder, Robin A

    2012-11-01

    Previous studies have demonstrated that single nucleotide polymorphisms (SNPs) of the sodium-bicarbonate co-transporter gene (SLC4A5) are associated with hypertension. We tested the hypothesis that SNPs in SLC4A5 are associated with salt sensitivity of blood pressure in 185 whites consuming an isocaloric constant diet with a randomized order of 7 days of low Na(+) (10 mmol/d) and 7 days of high Na(+) (300 mmol/d) intake. Salt sensitivity was defined as a ≥ 7-mm Hg increase in mean arterial pressure during a randomized transition between high and low Na(+) diet. A total of 35 polymorphisms in 17 candidate genes were assayed, 25 of which were tested for association. Association analyses with salt sensitivity revealed 3 variants that associated with salt sensitivity, 2 in SLC4A5 (P<0.001) and 1 in GRK4 (P=0.020). Of these, 2 SNPs in SLC4A5 (rs7571842 and rs10177833) demonstrated highly significant results and large effects sizes, using logistic regression. These 2 SNPs had P values of 1.0 × 10(-4) and 3.1 × 10(-4) with odds ratios of 0.221 and 0.221 in unadjusted regression models, respectively, with the G allele at both sites conferring protection. These SNPs remained significant after adjusting for body mass index and age (P=8.9 × 10(-5) and 2.6 × 10(-4) and odds ratios 0.210 and 0.286, respectively). Furthermore, the association of these SNPs with salt sensitivity was replicated in a second hypertensive population. Meta-analysis demonstrated significant associations of both SNPs with salt sensitivity (rs7571842 [P=1.2 × 10(-5)]; rs1017783 [P=1.1 × 10(-4)]). In conclusion, SLC4A5 variants are strongly associated with salt sensitivity of blood pressure in 2 separate white populations.

  20. Impact of sodium–glucose cotransporter 2 inhibitors on blood pressure

    Directory of Open Access Journals (Sweden)

    Reed JW

    2016-10-01

    control. Keywords: blood pressure, canagliflozin, dapagliflozin, empagliflozin, sodium–glucose cotransporter 2 inhibitors, type 2 diabetes

  1. Na(+)-D-glucose cotransporter in the kidney of Squalus acanthias: molecular identification and intrarenal distribution.

    Science.gov (United States)

    Althoff, Thorsten; Hentschel, Hartmut; Luig, Jutta; Schütz, Hendrike; Kasch, Myriam; Kinne, Rolf K-H

    2006-04-01

    Using primers against conserved regions of mammalian Na(+)-d-glucose cotransporters (SGLT), a cDNA was cloned from the kidney of spiny dogfish shark (Squalus acanthias). On the basis of comparison of amino acid sequence, membrane topology, and putative glycosylation and phosphorylation sites, the cDNA could be shown to belong to the family of sglt genes. Indeed, Na(+)-dependent d-glucose uptake could be demonstrated after expression of the gene in Xenopus laevis oocytes. In a dendrogram, the SGLT from shark kidney has a high homology to the mammalian SGLT2. Computer analysis revealed that the elasmobranch protein is most similar to the mammalian proteins in the transmembrane regions and contains already all the amino acids identified to be functionally important, suggesting early conservation during evolution. Extramembraneous loops show larger variations. This holds especially for loop 13, which has been implied as a phlorizin-binding domain. Antibodies were generated and the intrarenal distribution of the SGLT was studied in cryosections. In parallel, the nephron segments were identified by lectins. Positive immunoreactions were found in the proximal tubule in the early parts PIa and PIb and the late segment PIIb. The large PIIa segment of the proximal tubule showed no reaction. In contrast to the mammalian kidney also the late distal tubule, the collecting tubule, and the collecting duct showed immunoreactivity. The molecular information confirms previous vesicle studies in which a low affinity SGLT with a low stoichiometry has been observed and supports the notion of a similarity of the shark kidney SGLT to the mammalian SGLT2. Despite its presence in the late parts of the nephron, the absence of SGLT in the major part of the proximal tubule, the relatively low affinity, and in particular the low stoichiometry might explain the lack of a T(m) for d-glucose in the shark kidney.

  2. Role of sodium glucose cotransporter-2 inhibitors in type I diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Ahmadieh H

    2017-05-01

    Full Text Available Hala Ahmadieh,1 Nisrine Ghazal,2 Sami T Azar3 1Faculty of Medicine, Clinical Sciences Department, Beirut Arab University, 2Department of Endocrinology and Metabolism, American University of Beirut, Beirut, Lebanon; 3Department of Internal Medicine, Division of Endocrinology, American University of Beirut, New York, NY, USA Abstract: The burden of diabetes mellitus (DM in general has been extensively increasing over the past few years. Selective sodium glucose cotransporter-2 (SGLT2 inhibitors were extensively studied in type 2 DM and found to have sustained urinary glucose loss, improvement of glycemic control, in addition to their proven metabolic effects on weight, blood pressure, and cardiovascular benefits. Type 1 DM (T1D patients clearly depend on insulin therapy, which till today fails to achieve the optimal glycemic control and metabolic targets that are needed to prevent risk of complications. New therapies are obviously needed as an adjunct to insulin therapy in order to try to achieve optimal control in T1D. Many oral diabetic medications have been tried in T1D patients as an adjunct to insulin treatment and have shown conflicting results. Adjunctive use of SGLT2 inhibitors in addition to insulin therapies in T1D was found to have the potential to improve glycemic control along with decrease in the insulin doses, as has been shown in certain animal and short-term human studies. Furthermore, larger well-randomized studies are needed to better evaluate their efficacy and safety in patients with T1D. Euglycemic diabetic ketoacidosis incidences were found to be increased among users of SGLT2 inhibitors, although the incidence remains very low. Recent beneficial effects of ketone body production and this shift in fuel energetics have been suggested based on the findings of protective cardiovascular benefits associated with one of the SGLT2 inhibitors. Keywords: glycemic control, glycosylated hemoglobin, euglucemic diabetic ketoacidosis

  3. The Effect of WNK4 on the Na+-Cl- Cotransporter Is Modulated by Intracellular Chloride.

    Science.gov (United States)

    Bazúa-Valenti, Silvana; Chávez-Canales, María; Rojas-Vega, Lorena; González-Rodríguez, Xochiquetzal; Vázquez, Norma; Rodríguez-Gama, Alejandro; Argaiz, Eduardo R; Melo, Zesergio; Plata, Consuelo; Ellison, David H; García-Valdés, Jesús; Hadchouel, Juliette; Gamba, Gerardo

    2015-08-01

    It is widely recognized that the phenotype of familial hyperkalemic hypertension is mainly a consequence of increased activity of the renal Na(+)-Cl(-) cotransporter (NCC) because of altered regulation by with no-lysine-kinase 1 (WNK1) or WNK4. The effect of WNK4 on NCC, however, has been controversial because both inhibition and activation have been reported. It has been recently shown that the long isoform of WNK1 (L-WNK1) is a chloride-sensitive kinase activated by a low Cl(-) concentration. Therefore, we hypothesized that WNK4 effects on NCC could be modulated by intracellular chloride concentration ([Cl(-)]i), and we tested this hypothesis in oocytes injected with NCC cRNA with or without WNK4 cRNA. At baseline in oocytes, [Cl(-)]i was near 50 mM, autophosphorylation of WNK4 was undetectable, and NCC activity was either decreased or unaffected by WNK4. A reduction of [Cl(-)]i, either by low chloride hypotonic stress or coinjection of oocytes with the solute carrier family 26 (anion exchanger)-member 9 (SLC26A9) cRNA, promoted WNK4 autophosphorylation and increased NCC-dependent Na(+) transport in a WNK4-dependent manner. Substitution of the leucine with phenylalanine at residue 322 of WNK4, homologous to the chloride-binding pocket in L-WNK1, converted WNK4 into a constitutively autophosphorylated kinase that activated NCC, even without chloride depletion. Elimination of the catalytic activity (D321A or D321K-K186D) or the autophosphorylation site (S335A) in mutant WNK4-L322F abrogated the positive effect on NCC. These observations suggest that WNK4 can exert differential effects on NCC, depending on the intracellular chloride concentration. Copyright © 2015 by the American Society of Nephrology.

  4. Functional assessment of sodium chloride cotransporter NCC mutants in polarized mammalian epithelial cells.

    Science.gov (United States)

    Rosenbaek, Lena L; Rizzo, Federica; MacAulay, Nanna; Staub, Olivier; Fenton, Robert A

    2017-08-01

    The thiazide-sensitive sodium chloride cotransporter NCC is important for maintaining serum sodium (Na + ) and, indirectly, serum potassium (K + ) levels. Functional studies on NCC have used cell lines with native NCC expression, transiently transfected nonpolarized cell lines, or Xenopus laevis oocytes. Here, we developed the use of polarized Madin-Darby canine kidney type I (MDCKI) mammalian epithelial cell lines with tetracycline-inducible human NCC expression to study NCC activity and membrane abundance in the same system. In radiotracer assays, induced cells grown on filters had robust thiazide-sensitive and chloride dependent sodium-22 ( 22 Na) uptake from the apical side. To minimize cost and maximize throughput, assays were modified to use cells grown on plastic. On plastic, cells had similar thiazide-sensitive 22 Na uptakes that increased following preincubation of cells in chloride-free solutions. NCC was detected in the plasma membrane, and both membrane abundance and phosphorylation of NCC were increased by incubation in chloride-free solutions. Furthermore, in cells exposed for 15 min to low or high extracellular K + , the levels of phosphorylated NCC increased and decreased, respectively. To demonstrate that the system allows rapid and systematic assessment of mutated NCC, three phosphorylation sites in NCC were mutated, and NCC activity was examined. 22 Na fluxes in phosphorylation-deficient mutants were reduced to baseline levels, whereas phosphorylation-mimicking mutants were constitutively active, even without chloride-free stimulation. In conclusion, this system allows the activity, cellular localization, and abundance of wild-type or mutant NCC to be examined in the same polarized mammalian expression system in a rapid, easy, and low-cost fashion. Copyright © 2017 the American Physiological Society.

  5. Age-dependent susceptibility to phenobarbital-resistant neonatal seizures: role of chloride co-transporters

    Directory of Open Access Journals (Sweden)

    Seok Kyu eKang

    2015-05-01

    Full Text Available Ischemia in the immature brain is an important cause of neonatal seizures. Temporal evolution of acquired neonatal seizures and their response to anticonvulsants are of great interest, given the unreliability of the clinical correlates and poor efficacy of first-line anti-seizure drugs. The expression and function of the electroneutral chloride co-transporters KCC2 and NKCC1 influence the anti-seizure efficacy of GABAA-agonists. To investigate ischemia-induced seizure susceptibility and efficacy of the GABAA-agonist phenobarbital (PB, with NKCC1 antagonist bumetanide (BTN as an adjunct treatment, we utilized permanent unilateral carotid-ligation to produce acute ischemic-seizures in postnatal day 7, 10 and 12 CD1 mice. Immediate post-ligation video-electroencephalograms (EEGs quantitatively evaluated baseline and post-treatment seizure burdens. Brains were examined for stroke-injury and western blot analyses to evaluate the expression of KCC2 and NKCC1. Severity of acute ischemic seizures post-ligation was highest at P7. PB was an efficacious anti-seizure agent at P10 and P12, but not at P7. BTN failed as an adjunct, at all ages tested and significantly blunted PB-efficacy at P10. Significant acute post-ischemic downregulation of KCC2 was detected at all ages. At P7, males displayed higher age-dependent seizure susceptibility, associated with a significant developmental lag in their KCC2 expression. This study established a novel neonatal mouse model of PB-resistant seizures that demonstrates age/sex-dependent susceptibility. The age-dependent profile of KCC2 expression and its post-insult downregulation may underlie the PB-resistance reported in this model. Blocking NKCC1 with low-dose BTN following PB treatment failed to improve PB-efficacy.

  6. The Sodium Glucose Cotransporter SGLT1 Is an Extremely Efficient Facilitator of Passive Water Transport.

    Science.gov (United States)

    Erokhova, Liudmila; Horner, Andreas; Ollinger, Nicole; Siligan, Christine; Pohl, Peter

    2016-04-29

    The small intestine is void of aquaporins adept at facilitating vectorial water transport, and yet it reabsorbs ∼8 liters of fluid daily. Implications of the sodium glucose cotransporter SGLT1 in either pumping water or passively channeling water contrast with its reported water transporting capacity, which lags behind that of aquaporin-1 by 3 orders of magnitude. Here we overexpressed SGLT1 in MDCK cell monolayers and reconstituted the purified transporter into proteoliposomes. We observed the rate of osmotic proteoliposome deflation by light scattering. Fluorescence correlation spectroscopy served to assess (i) SGLT1 abundance in both vesicles and plasma membranes and (ii) flow-mediated dilution of an aqueous dye adjacent to the cell monolayer. Calculation of the unitary water channel permeability, pf, yielded similar values for cell and proteoliposome experiments. Neither the absence of glucose or Na(+), nor the lack of membrane voltage in vesicles, nor the directionality of water flow grossly altered pf Such weak dependence on protein conformation indicates that a water-impermeable occluded state (glucose and Na(+) in their binding pockets) lasts for only a minor fraction of the transport cycle or, alternatively, that occlusion of the substrate does not render the transporter water-impermeable as was suggested by computational studies of the bacterial homologue vSGLT. Although the similarity between the pf values of SGLT1 and aquaporin-1 makes a transcellular pathway plausible, it renders water pumping physiologically negligible because the passive flux would be orders of magnitude larger. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. MODULATION OF THE CARDIAC SODIUM/BICARBONATE COTRANSPORTER BY THE RENIN ANGIOTENSIN ALDOSTERONE SYSTEM: PATHOPHYSIOLOGICAL CONSEQUENCES.

    Directory of Open Access Journals (Sweden)

    Verónica Celeste De Giusti

    2014-01-01

    Full Text Available The sodium/bicarbonate cotransporter (NBC is one of the major alkalinizing mechanisms in the cardiomyocytes. It has been demonstrated the existence of at least two functional isoforms, one that promotes the co-influx of 1 molecule of Na+ per 1 molecule of HCO3- (electroneutral isoform; NBCn1 and the other one that generates the co-influx of 1 molecule of Na+ per 2 molecules of HCO3- (electrogenic isoform; NBCe1. Both isoforms are important to maintain intracellular pH (pHi and sodium concentration ([Na+]i. In addition, NBCe1 generates an anionic repolarizing current that modulates the action potential duration (APD. The renin-angiotensin-aldosterone system (RAAS is implicated in the modulation of almost all physiological cardiac functions and is also involved in the development and progression of cardiac diseases. It was reported that angiotensin II (Ang II exhibits an opposite effect on NBC isoforms: it activates NBCn1 and inhibits NBCe1. The activation of NBCn1 leads to an increase in pHi and [Na+]i, which indirectly, due to the stimulation of reverse mode of the Na+/Ca2+ exchanger (NCX, conduces to an increase in the intracellular Ca2+ concentration. On the other hand, the inhibition of NBCe1 generates an APD prolongation, potentially representing a risk of arrhythmias. In the last years, the potentially altered NBC function in pathological scenarios, as cardiac hypertrophy and ischemia-reperfusion, has raised increasing interest among investigators. This review attempts to draw the attention on the relevant regulation of NBC activity by RAAS, since it modulates pHi and [Na+]i, which are involved in the development of cardiac hypertrophy, the damage produced by ischemia-reperfusion and the generation of arrhythmic events, suggesting a potential role of NBC in cardiac diseases.

  8. Platelet-derived growth factor regulates K-Cl cotransport in vascular smooth muscle cells.

    Science.gov (United States)

    Zhang, Jing; Lauf, Peter K; Adragna, Norma C

    2003-03-01

    Platelet-derived growth factor (PDGF), a potent serum mitogen for vascular smooth muscle cells (VSMCs), plays an important role in membrane transport regulation and in atherosclerosis. K-Cl cotransport (K-Cl COT/KCC), the coupled-movement of K and Cl, is involved in ion homeostasis. VSMCs possess K-Cl COT activity and the KCC1 and KCC3 isoforms. Here, we report on the effect of PDGF on K-Cl COT activity and mRNA expression in primary cultures of rat VSMCs. K-Cl COT was determined as the Cl-dependent Rb influx and mRNA expression by semiquantitative RT-PCR. Twenty four-hour serum deprivation inhibited basal K-Cl COT activity. Addition of PDGF increased total protein content and K-Cl COT activity in a time-dependent manner. PDGF activated K-Cl COT in a dose-dependent manner, both acutely (10 min) and chronically (12 h). AG-1296, a selective inhibitor of the PDGF receptor tyrosine kinase, abolished these effects. Actinomycin D and cycloheximide had no effect on the acute PDGF activation of K-Cl COT, suggesting posttranslational regulation by the drug. Furthermore, PDGF increased KCC1 and decreased KCC3 mRNA expression in a time-dependent manner. These results indicate that chronic activation of K-Cl COT activity by PDGF may involve regulation of the two KCC mRNA isoforms, with KCC1 playing a dominant role in the mechanism of PDGF-mediated activation.

  9. Signal transduction mechanisms of K+-Cl- cotransport regulation and relationship to disease.

    Science.gov (United States)

    Adragna, N C; Ferrell, C M; Zhang, J; Di Fulvio, M; Temprana, C F; Sharma, A; Fyffe, R E W; Cool, D R; Lauf, P K

    2006-01-01

    The K+-Cl- cotransport (COT) regulatory pathways recently uncovered in our laboratory and their implication in disease state are reviewed. Three mechanisms of K+-Cl- COT regulation can be identified in vascular cells: (1) the Li+-sensitive pathway, (2) the platelet-derived growth factor (PDGF)-sensitive pathway and (3) the nitric oxide (NO)-dependent pathway. Ion fluxes, Western blotting, semi-quantitative RT-PCR, immunofluorescence and confocal microscopy were used. Li+, used in the treatment of manic depression, stimulates volume-sensitive K+-Cl- COT of low K+ sheep red blood cells at cellular concentrations 3 mM, causes cell swelling, and appears to regulate K+-Cl- COT through a protein kinase C-dependent pathway. PDGF, a potent serum mitogen for vascular smooth muscle cells (VSMCs), regulates membrane transport and is involved in atherosclerosis. PDGF stimulates VSM K+-Cl- COT in a time- and concentration-dependent manner, both acutely and chronically, through the PDGF receptor. The acute effect occurs at the post-translational level whereas the chronic effect may involve regulation through gene expression. Regulation by PDGF involves the signalling molecules phosphoinositides 3-kinase and protein phosphatase-1. Finally, the NO/cGMP/protein kinase G pathway, involved in vasodilation and hence cardiovascular disease, regulates K+-Cl- COT in VSMCs at the mRNA expression and transport levels. A complex and diverse array of mechanisms and effectors regulate K+-Cl- COT and thus cell volume homeostasis, setting the stage for abnormalities at the genetic and/or regulatory level thus effecting or being affected by various pathological conditions.

  10. Cloning and expression of sheep renal K-CI cotransporter-1.

    Science.gov (United States)

    Zhang, Jin J; Misri, Sandeep; Adragna, Norma C; Gagnon, Kenneth B E; Fyffe, Robert E W; Lauf, Peter K

    2005-01-01

    Sheep K-Cl cotransporter-1(shKCC1) cDNA was cloned from kidney by RT-PCR with an open reading frame of 3258 base pairs exhibiting 92%, 90%, 88% and 87% identity with pig, rabbit and human, rat and mouse KCC1 cDNAs, respectively, encoding an approximately 122 kDa polypeptide of 1086-amino acids. Hydropathy analysis reveals the familiar KCC1 topology with 12 transmembrane domains (TMDs) and the hydrophilic NH2-terminal (NTD) and COOH-terminal (CTD) domains both at the cytoplasmic membrane face. However, shKCC1 has two rather than one large extracellular loops (ECL): ECL3 between TMDs 5 and 6, and ECL6, between TMDs 11 and 12. The translated shKCC1 protein differs in 12 amino acid residues from other KCC1s, mainly within the NTD, ECL3, ICL4, ECL6, and CTD. Notably, a tyrosine residue at position 996 replaces aspartic acid conserved in all other species. Human embryonic kidney (HEK293) cells and mouse NIH/3T3 fibroblasts, transiently transfected with shKCCI-cDNA, revealed the glycosylated approximately 150 kDa proteins by Western blots and positive immunofluorescence-staining with polyclonal rabbit anti-ratKCC1 antibodies. ShKCC1 was functionally expressed in NIH/3T3 cells by an elevated basal Cl-dependent K influx measured with Rb as K-congener that was stimulated three-fold by the KCC-activator N-ethylmaleimide. Copyright (c) 2005 S. Karger AG, Basel.

  11. Internal magnesium, 2,3-diphosphoglycerate, and the regulation of the steady-state volume of human red blood cells by the Na/K/2Cl cotransport system

    Science.gov (United States)

    1992-01-01

    This study is concerned with the relationship between the Na/K/Cl cotransport system and the steady-state volume (MCV) of red blood cells. Cotransport rate was determined in unfractionated and density- separated red cells of different MCV from different donors to see whether cotransport differences contribute to the difference in the distribution of MCVs. Cotransport, studied in cells at their original MCVs, was determined as the bumetanide (10 microM)-sensitive 22Na efflux in the presence of ouabain (50 microM) after adjusting cellular Na (Nai) and Ki to achieve near maximal transport rates. This condition was chosen to rule out MCV-related differences in Nai and Ki that might contribute to differences in the net chemical driving force for cotransport. We found that in both unfractionated and density-separated red cells the cotransport rate was inversely correlated with MCV. MCV was correlated directly with red cell 2,3-diphosphoglycerate (DPG), whereas total red cell Mg was only slightly elevated in cells with high MCV. Thus intracellular free Mg (Mgifree) is evidently lower in red cells with high 2,3-DPG (i.e., high MCV) and vice versa. Results from flux measurements at their original MCVs, after altering Mgifree with the ionophore A23187, indicated a high Mgi sensitivity of cotransport: depletion of Mgifree inhibited and an elevation of Mgifree increased the cotransport rate. The apparent K0.5 for Mgifree was approximately 0.4 mM. Maximizing Mgifree at optimum Nai and Ki minimized the differences in cotransport rates among the different donors. It is concluded that the relative cotransport rate is regulated for cells in the steady state at their original cell volume, not by the number of copies of the cotransporter but by differences in Mgifree. The interindividual differences in Mgifree, determined primarily by differences in the 2,3-DPG content, are responsible for the differences in the relative cotransport activity that results in an inverse relationship

  12. Urine concentrating mechanism: impact of vascular and tubular architecture and a proposed descending limb urea-Na+ cotransporter

    Science.gov (United States)

    Dantzler, William H.; Pannabecker, Thomas L.

    2012-01-01

    We extended a region-based mathematical model of the renal medulla of the rat kidney, previously developed by us, to represent new anatomic findings on the vascular architecture in the rat inner medulla (IM). In the outer medulla (OM), tubules and vessels are organized around tightly packed vascular bundles; in the IM, the organization is centered around collecting duct clusters. In particular, the model represents the separation of descending vasa recta from the descending limbs of loops of Henle, and the model represents a papillary segment of the descending thin limb that is water impermeable and highly urea permeable. Model results suggest that, despite the compartmentalization of IM blood flow, IM interstitial fluid composition is substantially more homogeneous compared with OM. We used the model to study medullary blood flow in antidiuresis and the effects of vascular countercurrent exchange. We also hypothesize that the terminal aquaporin-1 null segment of the long descending thin limbs may express a urea-Na+ or urea-Cl− cotransporter. As urea diffuses from the urea-rich papillary interstitium into the descending thin limb luminal fluid, NaCl is secreted via the cotransporter against its concentration gradient. That NaCl is then reabsorbed near the loop bend, raising the interstitial fluid osmolality and promoting water reabsorption from the IM collecting ducts. Indeed, the model predicts that the presence of the urea-Na+ or urea- Cl− cotransporter facilitates the cycling of NaCl within the IM and yields a loop-bend fluid composition consistent with experimental data. PMID:22088433

  13. Deficiency of electroneutral K+-Cl- cotransporter 3 causes a disruption in impulse propagation along peripheral nerves.

    Science.gov (United States)

    Sun, Yuan-Ting; Lin, Thy-Sheng; Tzeng, Shun-Fen; Delpire, Eric; Shen, Meng-Ru

    2010-10-01

    Nerve conduction requires the fine tuning of ionic currents through delicate interactions between axons and Schwann cells. The K(+)-Cl(-) cotransporter (KCC) family includes four isoforms (KCC1-4) that play an important role in the maintenance of cellular osmotic homeostasis via the coupled electroneutral movement of K(+) and Cl(-) with concurrent water flux. Mutation in SLC12A6 gene encoding KCC3 results in an autosomal recessive disease, known as agenesis of the corpus callosum associated with peripheral neuropathy. Nevertheless, the role of KCC3 in nerve function remains a puzzle. In this study, the microscopic examination of KCC isoforms expressed in peripheral nerves showed high expression of KCC2-4 in nodal segments of the axons and in the perinucleus and microvilli of Schwann cells. The KCC inhibitor [[(dihydroindenyl)oxy]alkanoic acid] but not the Na(+)-K(+)-2Cl(-)-cotransport inhibitor (bumetanide) dose-dependently suppressed the amplitude and area of compound muscle action potential, indicating the involvement of KCC activity in peripheral nerve conduction. Furthermore, the amplitude and area under the curve were smaller, and the nerve conduction velocity was slower in nerves from KCC3(-/-) mice than in nerves from wild-type mice, while the expression pattern of KCC2 and KCC4 was similar in KCC3 kockout and wild-type strains. KCC3(-/-) mice also manifested a prominent motor deficit in the beam-walking test. This is the first study to demonstrate that the K(+)-Cl(-) cotransporter activity of KCC3 contributes to the propagation of action potentials along peripheral nerves. (c) 2010 Wiley-Liss, Inc.

  14. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics.

    Directory of Open Access Journals (Sweden)

    Adèle Salin-Cantegrel

    Full Text Available Loss-of-function of the potassium-chloride cotransporter 3 (KCC3 causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC, a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.

  15. The effects of sodium-glucose co-transporter 2 inhibitors in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Gluud, Lise Lotte; Christensen, Mikkel

    2014-01-01

    INTRODUCTION: Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) increase urinary glucose excretion through a reduced renal glucose reabsorption. We plan to perform a systematic review of SGLT-2i for treatment of type 2 diabetes. METHODS AND ANALYSIS: A systematic review with meta-analyses of r......INTRODUCTION: Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) increase urinary glucose excretion through a reduced renal glucose reabsorption. We plan to perform a systematic review of SGLT-2i for treatment of type 2 diabetes. METHODS AND ANALYSIS: A systematic review with meta......-analyses of randomised clinical trials on SGLT-2i versus placebo, other oral glucose lowering drugs or insulin for patients with type 2 diabetes will be performed. The primary end point will be the glycated haemoglobin. Secondary end points will include changes in body weight, body mass index, fasting plasma glucose......, plasma cholesterol, kidney and liver blood tests, blood pressure and adverse events. Electronic (the Cochrane Library, MEDLINE, EMBASE and the Science Citation Index) and manual searches will be performed. Meta-analyses will be performed and the results presented as mean differences for continuous...

  16. The Renal Sodium Bicarbonate Cotransporter NBCe2: Is It a Major Contributor to Sodium and pH Homeostasis?

    Science.gov (United States)

    Felder, Robin A; Jose, Pedro A; Xu, Peng; Gildea, John J

    2016-09-01

    The sodium bicarbonate cotransporter (NBCe2, aka NBC4) was originally isolated from the human testis and heart (Pushkin et al. IUBMB Life 50:13-19, 2000). Subsequently, NBCe2 was found in diverse locations where it plays a role in regulating sodium and bicarbonate transport, influencing intracellular, extracellular, interstitial, and ultimately plasma pH (Boron et al. J Exp Biol. 212:1697-1706, 2009; Parker and Boron, Physiol Rev. 93:803-959, 2013; Romero et al. Mol Asp Med. 34:159-182, 2013). NBCe2 is located in human and rodent renal-collecting duct and proximal tubule. While much is known about the two electrogenic sodium bicarbonate cotransporters, NBCe1 and NBCe2, in the regulation of sodium homeostasis and pH balance in the rodent kidney, little is known about their roles in human renal physiology. NBCe2 is located in the proximal tubule Golgi apparatus under basal conditions and then disperses throughout the cell, but particularly into the apical membrane microvilli, during various maneuvers that increase intracellular sodium. This review will summarize our current understanding of the distribution and function of NBCe2 in the human kidney and how genetic variants of its gene, SLC4A5, contribute to salt sensitivity of blood pressure.

  17. Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils.

    Science.gov (United States)

    Zhang, Miaoyue; Engelhardt, Irina; Šimůnek, Jirka; Bradford, Scott A; Kasel, Daniela; Berns, Anne E; Vereecken, Harry; Klumpp, Erwin

    2017-02-01

    Batch and saturated soil column experiments were conducted to investigate sorption and mobility of two 14 C-labeled contaminants, the hydrophobic chlordecone (CLD) and the sulfadiazine (SDZ), in the absence or presence of functionalized multi-walled carbon nanotubes (MWCNTs). The transport behaviors of CLD, SDZ, and MWCNTs were studied at environmentally relevant concentrations (0.1-10 mg L -1 ) and they were applied in the column studies at different times. The breakthrough curves and retention profiles were simulated using a numerical model that accounted for the advective-dispersive transport of all compounds, attachment/detachment of MWCNTs, equilibrium and kinetic sorption of contaminants, and co-transport of contaminants with MWCNTs. The experimental results indicated that the presence of mobile MWCNTs facilitated remobilization of previously deposited CLD and its co-transport into deeper soil layers, while retained MWCNTs enhanced SDZ deposition in the topsoil layers due to the increased adsorption capacity of the soil. The modeling results then demonstrated that the mobility of engineered nanoparticles (ENPs) in the environment and the high affinity and entrapment of contaminants to ENPs were the main reasons for ENP-facilitated contaminant transport. On the other hand, immobile MWCNTs had a less significant impact on the contaminant transport, even though they were still able to enhance the adsorption capacity of the soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Membrane potential and proton cotransport of alanine and phosphate as affected by permeant weak acids in Lemna gibba

    International Nuclear Information System (INIS)

    Basso, B.; Ullrich-Eberius, C.I.

    1987-01-01

    The treatment of Lemna gibba plants with the weak acids (trimethylacetic acid and butyric acid), used as tools to decrease intracellular pH, induced a hyperpolarization of membrane potential, dependent on the concentration of the undissociated permeant form of the weak acid and on the value of the resting potential. Measurements were carried out both with high potential and low potential plants and the maximum values of acid induced hyperpolarization were about 35 and 71 millivolts, respectively. Weak acids influenced also the transient light-dark membrane potential changes, typical for photosynthesizing material, suggesting a dependence of these changes on an acidification of cytoplasm. In the presence of the weak acids, the membrane depolarization induced by the cotransport of alanine and phosphate with protons was reduced; the maximum reduction (about 90%) was obtained with alanine during 2 millimolar trimethylacetic acid perfusion at pH 5. A strong inhibition of the uptake rates (up to 48% for [ 14 C]alanine and 68% for 32 P-phosphate) was obtained in the presence of the weak acids, both by decreasing the pH of the medium and by increasing the concentration of the acid. In these experimental conditions, the ATP level and O 2 uptake rates did not change significantly. These results constitute good evidence that H + /solute cotransport in Lemna, already known to be dependent on the electrochemical potential difference for protons, is also strongly regulated by the cytoplasmic pH value

  19. Dynamics of Na+,K+,2Cl- cotransporter and Na+,K+-ATPase expression in the branchial epithelium of brown trout (Salmo trutta) and Atlantic salmon (Salmo salar)

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Madsen, Steffen; Seidelin, Michel

    2002-01-01

    The dynamics of branchial Na+,K+,2Cl- cotransporter (NKCC) and Na+,K+-ATPase (NKA) expression were investigated in brown trout and Atlantic salmon during salinity shifts and the parr-smolt transformation, respectively. In the brown trout, Western blotting revealed that NKCC and NKA abundance...

  20. Contribution of Na+,HCO3--cotransport to cellular pH control in human breast cancer

    DEFF Research Database (Denmark)

    Bødtkjer, Ebbe; Moreira, José; Mele, Marco

    2013-01-01

    Genome-wide association studies recently linked the locus for Na(+) ,HCO(3) (-) -cotransporter NBCn1 (SLC4A7) to breast cancer susceptibility, yet functional insights have been lacking. To determine whether NBCn1, by transporting HCO(3) (-) into cells, may dispose of acid produced during high met...

  1. Stimulation of Na+-alanine cotransport activates a voltage-dependent conductance in single proximal tubule cells isolated from frog kidney

    Science.gov (United States)

    Robson, L; Hunter, M

    1999-01-01

    The swelling induced by Na+-alanine cotransport in proximal tubule cells of the frog kidney is followed by regulatory volume decrease (RVD). This RVD is inhibited by gadolinium (Gd3+), an inhibitor of stretch-activated channels, but is independent of extracellular Ca2+. In this study, the whole cell patch clamp technique was utilized to examine the effect of Na+-alanine cotransport on two previously identified volume- and Gd3+-sensitive conductances. One conductance is voltage dependent and anion selective (GVD) whilst the other is voltage independent and cation selective (GVI). Addition of 5 mM L-alanine to the bathing solution increased the whole cell conductance and gave a positive (depolarizing) shift in the reversal potential (Vrev, equivalent to the membrane potential in current-clamped cells) consistent with activation of Na+-alanine cotransport. Vrev shifted from -36 ± 4·9 to +12·9 ± 4·2 mV (n= 15). In the presence of alanine, the total whole cell conductance had several components including the cotransporter conductance and GVD and GVI. These conductances were separated using Gd3+, which inhibits both GVD and GVI, and the time dependency of GVD. Of these two volume-sensitive conductances, L-alanine elicited a specific increase in GVD, whereas GVI was unaffected. The L-alanine-induced activation of GVD was significantly reduced when cells were incubated in a hypertonic bathing solution. In summary, in single proximal tubule cells isolated from frog kidney, on stimulation of Na+-alanine cotransport GVD is activated, while GVI is unaffected. Taken with other evidence, this suggests that GVD is activated by cell swelling, consequent upon alanine entry, and may play a role as an anion efflux pathway during alanine-induced volume regulation. PMID:10226159

  2. Regulation of the Na+2Cl–K+ cotransporter in in vitro perfused rectal gland tubules of Squalus acanthias.

    Science.gov (United States)

    Warth, R; Bleich, M; Thiele, I; Lang, F; Greger, R

    1998-07-01

    Previously it has been shown that the Na+2Cl–K+ cotransporter accepts NH4 + at its K+ binding site. This property can be used to estimate its transport rates by adding NH4 + to the bath and measuring the initial furosemide-dependent rates of change in BCECF fluorescence. We have utilized this technique to determine the regulation of the furosemide-inhibitable Na+2Cl–K+ cotransporter in in vitroperfused rectal gland tubules (RGT) of Squalus acanthias. Addition of NH4 + to the bath (20 mmol/l) led to an initial alkalinization, corresponding to NH3 uptake. This was followed by an acidification, corresponding to NH4 + uptake. The rate of this uptake was quantified by exponential curve fitting and is given in arbitrary units (Δfluorescence/time). This acidification could be completely inhibited by furosemide. In the absence of any secretagogue preincubation of RGT in a low Cl– solution (6 mmol/l, low Cl–) for 10 min enhanced the uptake rate significantly from 4.04±0.51 to 12.7±1.30 (n=5). The addition of urea (200 mmol/l) was without effect, but the addition of 300 mmol/l mannitol (+300 mannitol) enhanced the rate significantly from 7.24±1.33 to 14.7±4.6 (n=6). Stimulation of NaCl secretion by a solution maximizing the cytosolic cAMP concentration (Stim) led to a significant increase in NH4 + uptake rate from 5.00±1.33 to 13.3±1.54 (n=6). Similar results were obtained in the additional presence of Ba2+ (1 mmol/l): the uptake rate was increased significantly from 4.23±0.34 to 15.1±1.86 (n=16). In the presence of Stim low Cl– had no additional effect on the uptake rate: 15.1±3.1 versus 15.2±2.8 in high Cl– (n=6). The uptake rate in Stim containing additional +300 mannitol (22.3±4.0, n=5) was not significantly different from that obtained with Stim or +300 mannitol alone. By whatever mechanism the NH4 + uptake rate was increased furosemide (500 µmol/l) always reduced this rate to control values. Hence three manoeuvres enhanced furosemide

  3. Diabetic Ketoacidosis in a Patient with Type 2 Diabetes After Initiation of Sodium-Glucose Cotransporter 2 Inhibitor Treatment

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Bagger, Jonatan I; Knop, Filip K

    2016-01-01

    Sodium-glucose cotransporter 2 inhibitors (SGLT2i) were recently introduced for the treatment of type 2 diabetes (T2D). SGLT2i lower plasma glucose by inhibiting the renal reuptake of glucose leading to glucosuria. Generally, these drugs are considered safe to use. However, recently, SGLT2i have...... been suggested to predispose to ketoacidosis. Here, we present a case of diabetic ketoacidosis (DKA) developed in an obese, poorly controlled male patient with T2D treated with the SGLT2i dapagliflozin. He was admitted with DKA 5 days after the initiation of treatment with the SGLT2i dapagliflozin...... 72 hr with insulin as the only glucose-lowering therapy. After 1 month, dapagliflozin was reintroduced as add-on to insulin with no recurrent signs of ketoacidosis. During acute illness or other conditions with increased insulin demands in diabetes, SGLT2i may predispose to the formation of ketone...

  4. The effects of sodium-glucose co-transporter 2 inhibitors in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Gluud, Lise Lotte; Christensen, Mikkel

    2014-01-01

    INTRODUCTION: Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) increase urinary glucose excretion through a reduced renal glucose reabsorption. We plan to perform a systematic review of SGLT-2i for treatment of type 2 diabetes. METHODS AND ANALYSIS: A systematic review with meta......-analyses of randomised clinical trials on SGLT-2i versus placebo, other oral glucose lowering drugs or insulin for patients with type 2 diabetes will be performed. The primary end point will be the glycated haemoglobin. Secondary end points will include changes in body weight, body mass index, fasting plasma glucose...... to the knowledge regarding the beneficial and harmful effects of SGLT-2i in patients with type 2 diabetes. We plan to publish the study irrespective of the results. RESULTS: The study will be disseminated by peer-review publication and conference presentation. TRIAL REGISTRATION NUMBER: PROSPERO CRD42014008960...

  5. Evidence for the involvement of Ala 166 in coupling Na(+) to sugar transport through the human Na(+)/glucose cotransporter

    DEFF Research Database (Denmark)

    Meinild, A K; Loo, D D; Hirayama, B A

    2001-01-01

    . The affinity for Na(+) was unchanged compared to that of hSGLT1, whereas the sugar affinity was reduced and sugar specificity was altered. There was a reduction in the turnover rate of the transporter, and in contrast to that of hSGLT1, the turnover rate depended on the sugar molecule. Exposure of A166C......We mutated residue 166, located in the putative Na(+) transport pathway between transmembrane segments 4 and 5 of human Na(+)/glucose cotransporter (hSGLT1), from alanine to cysteine (A166C). A166C was expressed in Xenopus laevis oocytes, and electrophysiological methods were used to assay function...... to MTSEA and MTSET, but not MTSES, abolished sugar transport. Accessibility of A166C to alkylating reagents was independent of protein conformation, indicating that the residue is always accessible from the extracellular surface. Sugar and phlorizin did not protect the residue from being alkylated...

  6. Cotransport of Herbaspirillum chlorophenolicum FA1 and heavy metals in saturated porous media: column studies and modeling approaches

    Science.gov (United States)

    Li, X.; Xu, H.; Wu, J.

    2017-12-01

    For in situ biodegradation of organic contaminants in soil and groundwater, precise prediction and monitoring of the movement of the bio-agent is vital for the effectiveness of the subsurface bioremediation technologies. Therefore, the fate and transport of functional microorganisms in porous media has been extensively investigated in the literature, and the effects of a number of physical and chemical factors have been explored. During the bioremediation of contaminated sites, it is highly likely that functional bacteria and heavy metals would be simultaneously present for heavy metals often co-exist with organic contaminants like polycyclic aromatic hydrocarbons (PAHs) in polluted environment. To date, relevant studies on the interactions between heavy metals and functional agents such as PAHs-degrading bacteria are lacking and thus require investigation. In this study, the cotransport of bioremediation agents and heavy metals were evaluated through batch and column experiments. Herbaspirillum chlorophenolicum FA1, a pure bacterial strain capable of absorbing heavy metals and degrading polycyclic aromatic hydrocarbons (PAHs), was used as the model remediation agent, and metal ions of Pb(Ⅱ) and Cd(Ⅱ) were used as the representative heavy metals. Effects of metal species, the concentration of heavy metals, the sequence of entering the media, and the activity of biomass were investigated in detail. In addition, numerical simulations of breakthrough curves (BTC) data were also performed for information gathering. Results of this study could advance our understanding of interactions between functional bacteria and heavy metals during bioremediation process and help to develop successful bioremediation strategies.This work was financially supported by the National Natural Science Foundation of China -Xinjiang Project (U1503282), the National Natural Science Foundation of China (41030746, 41102148), and the Natural Science Foundation of Jiangsu Province (BK20151385

  7. Flozins, inhibitors of type 2 renal sodium-glucose co-transporter – not only antihyperglycemic drugs

    Directory of Open Access Journals (Sweden)

    Mizerski Grzegorz

    2015-09-01

    Full Text Available The kidneys play a crucial role in the regulation of the carbohydrate metabolism. In normal physiological conditions, the glucose that filters through the renal glomeruli is subsequently nearly totally reabsorbed in the proximal renal tubules. Two transporters are engaged in this process: sodium-glucose co-transporter type 1 (SGLT1, and sodium-glucose co-transporter type type 2 (SGLT2 - this being located in the luminal membrane of the renal tubular epithelial cells. It was found that the administration of dapagliflozin, a selective SGLT2 inhibitor, in patients with type 2 diabetes, is associated with the reduction of HbA1c concentration by 0.45-1.11%. Additional benefits from the treatment with dapagliflozin are the reduction of arterial blood pressure and a permanent reduction of body weight. This outcome is related to the effect of osmotic diuresis and to the considerable loss of the glucose load by way of urine excretion. Dapagliflozin may be successfully applied in type 2 diabetes monotherapy, as well as in combined therapy (including insulin, where it is equally effective as other oral anti-diabetic drugs. Of note: serious adverse effects of dapagliflozin administration are rarely observed. What is more, episodes of severe hypoglycaemia related with the treatment occur only sporadically, most often in the course of diabetes polytherapy. The most frequent effects of the SGLT2 inhibitors are inseparably associated with the mechanism of their action (the glucuretic effect, and cover urogenital infections with a mild clinical course. At present, clinical trials are being continued of the administration of several subsequent drugs from this group, the most advanced of these being the use of canagliflozin and empagliflozin.

  8. Cotransport of clay colloids and viruses through water-saturated vertically oriented columns packed with glass beads: Gravity effects.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2016-03-01

    The cotransport of clay colloids and viruses in vertically oriented laboratory columns packed with glass beads was investigated. Bacteriophages MS2 and ΦX174 were used as model viruses, and kaolinite (ΚGa-1b) and montmorillonite (STx-1b) as model clay colloids. A steady flow rate of Q=1.5 mL/min was applied in both vertical up (VU) and vertical down (VD) flow directions. In the presence of KGa-1b, estimated mass recovery values for both viruses were higher for VD than VU flow direction, while in the presence of STx-1b the opposite was observed. However, for all cases examined, the produced mass of viruses attached onto suspended clay particles were higher for VD than VU flow direction, suggesting that the flow direction significantly influences virus attachment onto clays, as well as packed column retention of viruses attached onto suspended clays. KGa-1b hindered the transport of ΦX174 under VD flow, while STx-1b facilitated the transport of ΦX174 under both VU and VD flow directions. Moreover, KGa-1b and STx-1b facilitated the transport of MS2 in most of the cases examined except of the case where KGa-1b was present under VD flow. Also, the experimental data were used for the estimation of virus surface-coverages and virus surface concentrations generated by virus diffusion-limited attachment, as well as virus attachment due to sedimentation. Both sedimentation and diffusion limited virus attachment were higher for VD than VU flow, except the case of MS2 and STx-1b cotransport. The diffusion-limited attachment was higher for MS2 than ΦΧ174 for all cases examined. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Expression of Na+/HCO3- co-transporter proteins (NBCs) in rat and human skeletal muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas Møller; Kristensen, Michael; Juel, Carsten

    2004-01-01

    AIM: Sodium/bicarbonate co-transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. METHODS AND RESULTS: Western blotting of muscle homogenates...... the T-tubules. The two NBCs localized in muscle have distinct fibre type distributions. CONCLUSIONS: Skeletal muscle possesses two variants of the sodium/bicarbonate co-transporter (NBC) isoforms, which have been called NBCe1 and NBCe2....... and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate...

  10. Vasoconstriction triggered by hydrogen sulfide: Evidence for Na+,K+,2Cl-cotransport and L-type Ca2+ channel-mediated pathway.

    Science.gov (United States)

    Orlov, Sergei N; Gusakova, Svetlana V; Smaglii, Liudmila V; Koltsova, Svetlana V; Sidorenko, Svetalana V

    2017-12-01

    This study examined the dose-dependent actions of hydrogen sulfide donor sodium hydrosulphide (NaHS) on isometric contractions and ion transport in rat aorta smooth muscle cells (SMC). Isometric contraction was measured in ring aortas segments from male Wistar rats. Activity of Na + /K + -pump and Na + ,K + ,2Cl - cotransport was measured in cultured endothelial and smooth muscle cells from the rat aorta as ouabain-sensitive and ouabain-resistant, bumetanide-sensitive components of the 86 Rb influx, respectively. NaHS exhibited the bimodal action on contractions triggered by modest depolarization ([K + ] o =30 mM). At 10 -4 M, NaHS augmented contractions of intact and endothelium-denuded strips by ~ 15% and 25%, respectively, whereas at concentration of 10 -3  M it decreased contractile responses by more than two-fold. Contractions evoked by 10 -4  M NaHS were completely abolished by bumetanide, a potent inhibitor of Na + ,K + ,2Cl - cotransport, whereas the inhibition seen at 10 -3  M NaHS was suppressed in the presence of K + channel blocker TEA. In cultured SMC, 5×10 -5  M NaHS increased Na + ,K + ,2Cl - - cotransport without any effect on the activity of this carrier in endothelial cells. In depolarized SMC, 45 Ca influx was enhanced in the presence of 10 -4  M NaHS and suppressed under elevation of [NaHS] up to 10 -3  M. 45 Ca influx triggered by 10 -4  M NaHS was abolished by bumetanide and L-type Ca 2+ channel blocker nicardipine. Our results strongly suggest that contractions of rat aortic rings triggered by low doses of NaHS are mediated by activation of Na + ,K + ,2Cl - cotransport and Ca 2+ influx via L-type channels.

  11. Compensatory role of the NBCn1 sodium/bicarbonate cotransporter on Ca2+-induced mitochondrial swelling in hypertrophic hearts.

    Science.gov (United States)

    Vargas, Lorena A; Velasquez, Fernanda Carrizo; Alvarez, Bernardo V

    2017-03-01

    NBC Na + /HCO 3 - cotransporter (NBCn1) and NHE1 Na + /H + exchanger have been associated with cardiac disorders and recently located in coronary endothelial cells (CEC) and cardiomyocytes mitochondria, respectively. Mitochondrial NHE1 blockade delays permeability transition pore (MPTP) opening and reduces superoxide levels, two critical events exacerbated in cells of diseased hearts. Conversely, activation of NBCn1 prevented apoptosis in CEC subjected to ischemic stress. We characterized the role of the NHE1 and NBCn1 transporters in heart mitochondria from hypertrophic (SHR) and control (Wistar) rats. Expression of NHE1 was analyzed in left ventricular mitochondrial lysates (LVML), by immunoblots. NHE1 expression increased by ~40% in SHR compared to control (P < 0.05, n = 4). To examine NHE1-mediated Na + /H + exchange activity in cardiac hypertrophy, mitochondria were loaded with BCECF-AM dye and the maximal rate of pHm change measured after the addition of 50 mM NaCl. SHR mitochondria had greater changes in pHm compared to Wistar, 0.10 ± 0.01 vs. 0.06 ± 0.01, respectively (P < 0.05, n = 5). In addition, mitochondrial suspensions from SHR and control myocardium were exposed to 200 μM CaCl 2 to induce MPTP opening (light-scattering decrease, LSD) and swelling. Surprisingly, SHR rats showed smaller LSD and a reduction in mitochondrial swelling, 67 ± 10% (n = 15), compared to control, 100 ± 8% (n = 13). NBC inhibition with S0859 (1 μM) significantly increased swelling in both control 139 ± 10% (n = 8) and SHR 115 ± 10% (n = 4). Finally, NBCn1 Na + /HCO 3 - cotransporter increased by twofold its expression in SHR LVML, compared to normal (P < 0.05, n = 5). We conclude that increased NBCn1 activity may play a compensatory role in hypertrophic hearts, protecting mitochondria from Ca 2+ -induced MPTP opening and swelling.

  12. Sodium-glucose co-transporter 2 (SGLT2 inhibitors: a growing class of anti-diabetic agents

    Directory of Open Access Journals (Sweden)

    Eva M Vivian

    2014-12-01

    Full Text Available Although several treatment options are available to reduce hyperglycemia, only about half of individuals with diagnosed diabetes mellitus (DM achieve recommended glycemic targets. New agents that reduce blood glucose concentrations by novel mechanisms and have acceptable safety profiles are needed to improve glycemic control and reduce the complications associated with type 2 diabetes mellitus (T2DM. The renal sodium-glucose co-transporter 2 (SGLT2 is responsible for reabsorption of most of the glucose filtered by the kidney. Inhibitors of SGLT2 lower blood glucose independent of the secretion and action of insulin by inhibiting renal reabsorption of glucose, thereby promoting the increased urinary excretion of excess glucose. Canagliflozin, dapagliflozin, and empagliflozin are SGLT2 inhibitors approved as treatments for T2DM in the United States, Europe, and other countries. Canagliflozin, dapagliflozin, and empagliflozin increase renal excretion of glucose and improve glycemic parameters in patients with T2DM when used as monotherapy or in combination with other antihyperglycemic agents. Treatment with SGLT2 inhibitors is associated with weight reduction, lowered blood pressure, and a low intrinsic propensity to cause hypoglycemia. Overall, canagliflozin, dapagliflozin, and empagliflozin are well tolerated. Cases of genital infections and, in some studies, urinary tract infections have been more frequent in canagliflozin-, dapagliflozin-, and empagliflozin-treated patients compared with those receiving placebo. Evidence from clinical trials suggests that SGLT2 inhibitors are a promising new treatment option for T2DM.

  13. Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors from Natural Products: Discovery of Next-Generation Antihyperglycemic Agents.

    Science.gov (United States)

    Choi, Chang-Ik

    2016-08-27

    Diabetes mellitus is a chronic condition associated with the metabolic impairment of insulin actions, leading to the development of life-threatening complications. Although many kinds of oral antihyperglycemic agents with different therapeutic mechanisms have been marketed, their undesirable adverse effects, such as hypoglycemia, weight gain, and hepato-renal toxicity, have increased demand for the discovery of novel, safer antidiabetic drugs. Since the important roles of the sodium-glucose cotransporter 2 (SGLT2) for glucose homeostasis in the kidney were recently elucidated, pharmacological inhibition of SGLT2 has been considered a promising therapeutic target for the treatment of type 2 diabetes. Since the discovery of the first natural SGLT2 inhibitor, phlorizin, several synthetic glucoside analogs have been developed and introduced into the market. Furthermore, many efforts to find new active constituents with SGLT2 inhibition from natural products are still ongoing. This review introduces the history of research on the development of early-generation SGLT2 inhibitors, and recent progress on the discovery of novel candidates for SGLT2 inhibitor from several natural products that are widely used in traditional herbal medicine.

  14. Quality of methodological reporting of randomized clinical trials of sodium-glucose cotransporter-2 (sglt2 inhibitors

    Directory of Open Access Journals (Sweden)

    Hadeel Alfahmi

    2017-01-01

    Full Text Available Sodium-glucose cotransporter-2 (SGLT2 inhibitors are a new class of medicines approved recently for the treatment of type 2 diabetes. To improve the quality of randomized clinical trial (RCT reports, the Consolidated Standards of Reporting Trials (CONSORT statement for methodological features was created. For achieving our objective in this study, we assessed the quality of methodological reporting of RCTs of SGLT2 inhibitors according to the 2010 CONSORT statement. We reviewed and analyzed the methodology of SGLT2 inhibitors RCTs that were approved by the Food & Drug Administration (FDA. Of the 27 trials, participants, eligibility criteria, and additional analyses were reported in 100% of the trials. In addition, trial design, interventions, and statistical methods were reported in 96.3% of the trials. Outcomes were reported in 93.6% of the trials. Settings were reported in 85.2% of the trials. Blinding and sample size were reported in 66.7 and 59.3% of the trials, respectively. Sequence allocation and the type of randomization were reported in 63 and 74.1% of the trials, respectively. Besides those, a few methodological items were inadequate in the trials. Allocation concealment was inadequate in most of the trials. It was reported only in 11.1% of the trials. The majority of RCTs have high percentage adherence for more than half of the methodological items of the 2010 CONSORT statement.

  15. Sodium-Glucose Cotransporter 2 (SGLT2 Inhibitors from Natural Products: Discovery of Next-Generation Antihyperglycemic Agents

    Directory of Open Access Journals (Sweden)

    Chang-Ik Choi

    2016-08-01

    Full Text Available Diabetes mellitus is a chronic condition associated with the metabolic impairment of insulin actions, leading to the development of life-threatening complications. Although many kinds of oral antihyperglycemic agents with different therapeutic mechanisms have been marketed, their undesirable adverse effects, such as hypoglycemia, weight gain, and hepato-renal toxicity, have increased demand for the discovery of novel, safer antidiabetic drugs. Since the important roles of the sodium-glucose cotransporter 2 (SGLT2 for glucose homeostasis in the kidney were recently elucidated, pharmacological inhibition of SGLT2 has been considered a promising therapeutic target for the treatment of type 2 diabetes. Since the discovery of the first natural SGLT2 inhibitor, phlorizin, several synthetic glucoside analogs have been developed and introduced into the market. Furthermore, many efforts to find new active constituents with SGLT2 inhibition from natural products are still ongoing. This review introduces the history of research on the development of early-generation SGLT2 inhibitors, and recent progress on the discovery of novel candidates for SGLT2 inhibitor from several natural products that are widely used in traditional herbal medicine.

  16. Characterization and comparison of sodium-glucose cotransporter 2 inhibitors: Part 2. Antidiabetic effects in type 2 diabetic mice

    Directory of Open Access Journals (Sweden)

    Atsuo Tahara

    2016-07-01

    Full Text Available Previously we investigated the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six sodium-glucose cotransporter (SGLT 2 inhibitors commercially available in Japan using normal and diabetic mice. We classified the SGLT2 inhibitors with respect to duration of action as either long-acting (ipragliflozin and dapagliflozin or intermediate-acting (tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin. In the present study, antidiabetic effects of repeated administration of these SGLT2 inhibitors in type 2 diabetic mice were investigated. When repeatedly administered for 4 weeks, all SGLT2 inhibitors significantly exhibited antihyperglycemic, antihyperinsulinemic, and pancreas-protective effects, as well as insulin resistance-improving effects. When compared at doses producing comparable reduction in hyperglycemia across all drugs, the antidiabetic effects of ipragliflozin and dapagliflozin were more potent than those of the other four drugs, but these differences among the six drugs were not statistically significant. Further, an oral glucose tolerance test performed after repeated administration demonstrated significant improvement in glucose tolerance only with ipragliflozin and dapagliflozin, implying improved insulin resistance and secretion. Taken together, these findings demonstrate that, although all SGLT2 inhibitors exert antidiabetic effects in type 2 diabetic mice, these pharmacologic effects might be slightly superior with the long-acting drugs, which are able to provide favorable blood glucose control throughout the day.

  17. Clinical risk factors predicting genital fungal infections with sodium-glucose cotransporter 2 inhibitor treatment: The ABCD nationwide dapagliflozin audit.

    Science.gov (United States)

    Thong, Ken Yan; Yadagiri, Mahender; Barnes, Dennis Joseph; Morris, David Stuart; Chowdhury, Tahseen Ahmad; Chuah, Ling Ling; Robinson, Anthony Michael; Bain, Stephen Charles; Adamson, Karen Ann; Ryder, Robert Elford John

    2018-02-01

    Treatment of type 2 diabetes with sodium-glucose cotransporter 2 (SGLT2) inhibitors may result in genital fungal infections. We investigated possible risk factors for developing such infections among patients treated with the SGLT2 inhibitor dapagliflozin. The Association of British Clinical Diabetologists (ABCD) collected data on patients treated with dapagliflozin in routine clinical practice from 59 diabetes centres. We assessed possible associations of patient's age, diabetes duration, body mass index, glycated haemoglobin, renal function, patient sex, ethnicity and prior genital fungal infection, urinary tract infection, urinary incontinence or nocturia, with the occurrence of ≥1 genital fungal infection within 26 weeks of treatment. 1049 out of 1116 patients (476 women, 573 men) were analysed. Baseline characteristics were, mean±SD, age 56.7±10.2years, BMI 35.5±6.9kg/m 2 and HbA 1c 9.4±1.5%. Only patient sex (13.2% women vs 3.3% men) and prior history of genital fungal infection (21.6% vs 7.3%) were found to be associated with occurrence of genital fungal infections after dapagliflozin treatment, adjusted OR 4.22 [95%CI 2.48,7.19], Prisks of developing genital fungal infections with dapagliflozin treatment. Copyright © 2017 Primary Care Diabetes Europe. All rights reserved.

  18. Benefits and Harms of Sodium-Glucose Co-Transporter 2 Inhibitors in Patients with Type 2 Diabetes

    DEFF Research Database (Denmark)

    Storgaard, Heidi; Gluud, Lise L; Bennett, Cathy

    2016-01-01

    OBJECTIVE: Sodium-glucose co-transporter 2 inhibitors (SGLT2-i) are a novel drug class for the treatment of diabetes. We aimed at describing the maximal benefits and risks associated with SGLT2-i for patients with type 2 diabetes. DESIGN: Systematic review and meta-analysis. DATA SOURCES AND STUDY......, ketoacidosis and CVD. Secondary outcomes were fasting plasma glucose, body weight, blood pressure, heart rate, lipids, liver function tests, creatinine and adverse events including infections. The quality of the evidence was assessed using GRADE. RESULTS: Meta-analysis of 34 RCTs with 9,154 patients showed...... to low quality evidence). Analysis of 12 RCTs found a beneficial effect of SGLT2-i on HbA1c compared with OAD (-0.20%, -0.28 to -0.13%; moderate quality evidence). CONCLUSION: This review includes a large number of patients with type 2 diabetes and found that SGLT2-i reduces HbA1c with a notable...

  19. Sodium-glucose co-transporter (SGLT) and glucose transporter (GLUT) expression in the kidney of type 2 diabetic subjects.

    Science.gov (United States)

    Norton, Luke; Shannon, Christopher E; Fourcaudot, Marcel; Hu, Cheng; Wang, Niansong; Ren, Wei; Song, Jun; Abdul-Ghani, Muhammad; DeFronzo, Ralph A; Ren, Jimmy; Jia, Weiping

    2017-09-01

    The sodium-glucose co-transporters (SGLTs) are responsible for the tubular reabsorption of filtered glucose from the kidney into the bloodstream. The inhibition of SGLT2-mediated glucose reabsorption is a novel and highly effective strategy to alleviate hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). However, the effectiveness of SGLT2 inhibitor therapy is diminished due, in part, to a compensatory increase in the maximum reabsorptive capacity (Tm) for glucose in patients with T2DM. We hypothesized that this increase in Tm could be explained by an increase in the tubular expression of SGLT and glucose transporters (GLUT) in these patients. To examine this, we obtained human kidney biopsy specimens from patients with or without T2DM and examined the mRNA expression of SGLTs and GLUTs. The expression of SGLT1 is markedly increased in the kidney of patients with T2DM, and SGLT1 mRNA is highly and significantly correlated with fasting and postprandial plasma glucose and HbA1c. In contrast, our data demonstrate that the levels of SGLT2 and GLUT2 mRNA are downregulated in diabetic patients, but not to a statistically significant level. These important findings are clinically significant and may have implications for the treatment of T2DM using strategies that target SGLT transporters in the kidney. © 2017 John Wiley & Sons Ltd.

  20. Transport activity of the sodium bicarbonate cotransporter NBCe1 is enhanced by different isoforms of carbonic anhydrase.

    Directory of Open Access Journals (Sweden)

    Christina Schueler

    Full Text Available Transport metabolons have been discussed between carbonic anhydrase II (CAII and several membrane transporters. We have now studied different CA isoforms, expressed in Xenopus oocytes alone and together with the electrogenic sodium bicarbonate cotransporter 1 (NBCe1, to determine their catalytic activity and their ability to enhance NBCe1 transport activity. pH measurements in intact oocytes indicated similar activity of CAI, CAII and CAIII, while in vitro CAIII had no measurable activity and CAI only 30% of the activity of CAII. All three CA isoforms increased transport activity of NBCe1, as measured by the transport current and the rate of intracellular sodium rise in oocytes. Two CAII mutants, altered in their intramolecular proton pathway, CAII-H64A and CAII-Y7F, showed significant catalytic activity and also enhanced NBCe1 transport activity. The effect of CAI, CAII, and CAII mutants on NBCe1 activity could be reversed by blocking CA activity with ethoxyzolamide (EZA, 10 µM, while the effect of the less EZA-sensitive CAIII was not reversed. Our results indicate that different CA isoforms and mutants, even if they show little enzymatic activity in vitro, may display significant catalytic activity in intact cells, and that the ability of CA to enhance NBCe1 transport appears to depend primarily on its catalytic activity.

  1. Nitric oxide signaling pathway regulates potassium chloride cotransporter-1 mRNA expression in vascular smooth muscle cells.

    Science.gov (United States)

    Di Fulvio, M; Lauf, P K; Adragna, N C

    2001-11-30

    Rat vascular smooth muscle cells (VSMCs) express at least two mRNAs for K-Cl cotransporters (KCC): KCC1 and KCC3. cGMP-dependent protein kinase I regulates KCC3 mRNA expression in these cells. Here, we show evidence implicating the nitric oxide (NO)/cGMP signaling pathway in the expression of KCC1 mRNA, considered to be the major cell volume regulator. VSMCs, expressing soluble guanylyl cyclase (sGC) and PKG-I isoforms showed a time- and concentration-dependent increase in KCC1 mRNA levels after treatment with sodium nitroprusside as demonstrated by semiquantitative RT-PCR. sGC-dependent regulation of KCC1 mRNA expression was confirmed using YC-1, a NO-independent sGC stimulator. The sGC inhibitor LY83583 blocked the effects of sodium nitroprusside and YC-1. Moreover, 8-Br-cGMP increased KCC1 mRNA expression in a concentration- and time-dependent fashion. The 8-Br-cGMP effect was partially blocked by KT5823 but not by actinomycin D. However, actinomycin D and cycloheximide increased basal KCC1 mRNA in an additive manner, suggesting different mechanisms of action for both drugs. These findings suggest that in VSMCs, the NO/cGMP-signaling pathway participates in KCC1 mRNA regulation at the post-transcriptional level.

  2. Safety of Sodium-Glucose Co-Transporter 2 Inhibitors during Ramadan Fasting: Evidence, Perceptions and Guidelines

    Directory of Open Access Journals (Sweden)

    Salem A. Beshyah

    2016-06-01

    Full Text Available Sodium-glucose co-transporter 2 (SGLT2 inhibitors are a new glucose-lowering therapy for T2DM with documented benefits on blood glucose, hypertension, weight reduction and long term cardiovascular benefit. They have an inherent osmotic diuretic effect and lead to some volume loss and possible dehydration. There is some concern about the safety of using SGLT2 inhibitors in Muslim type 2 diabetes mellitus (T2DM patients during the fast during Ramadan. Currently, there is a dearth of research data to help guide physicians and reassure patients.  One study confirmed good glycemic control with less risk of hypoglycemia and no marked volume depletion. Data in the elderly and in combination with diuretics are reassuring of their safe to use in Ramadan in general. SGLT2 inhibitor-related diabetic ketoacidosis has not been reported during Ramadan and is unlikely to be relevant. Survey of physicians revealed that the majority felt that SGLT2 inhibitors are generally safe in T2DM patients during Ramadan fasting but should be discontinued in certain high risk patients. Some professional groups with interest in diabetes and Ramadan fasting included SGLT2 inhibitors in their guidelines on management of diabetes during Ramadan. They acknowledged the lack of trial data, recommended caution in high risk groups, advised regular monitoring and emphasized pre-Ramadan patients’ education. In conclusion, currently, knowledge, data and experience with SGLT2 inhibitors in Ramadan are limited. Nonetheless, stable patients with normal kidney function and low risk of dehydration may safely use the SGLT2 inhibitors therapy. Higher risk patients should be observed carefully and managed on individual basis.

  3. Empagliflozin: a new sodium-glucose co-transporter 2 (SGLT2 inhibitor for the treatment of type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Joshua J Neumiller

    2014-06-01

    Full Text Available Type 2 diabetes is increasing in prevalence worldwide, and hyperglycemia is often poorly controlled despite a number of therapeutic options. Unlike previously available agents, sodium-glucose co-transporter 2 (SGLT2 inhibitors offer an insulin-independent mechanism for improving blood glucose levels, since they promote urinary glucose excretion (UGE by inhibiting glucose reabsorption in the kidney. In addition to glucose control, SGLT2 inhibitors are associated with weight loss and blood pressure reductions, and do not increase the risk of hypoglycemia. Empagliflozin is a selective inhibitor of SGLT2, providing dose-dependent UGE increases in healthy volunteers, with up to 90 g of glucose excreted per day. It can be administered orally, and studies of people with renal or hepatic impairment indicated empagliflozin needed no dose adjustment based on pharmacokinetics. In Phase II trials in patients with type 2 diabetes, empagliflozin provided improvements in glycosylated hemoglobin (HbA1c and other measures of glycemic control when given as monotherapy or add-on to metformin, as well as reductions in weight and systolic blood pressure. As add-on to basal insulin, empagliflozin not only improved HbA1c levels but also reduced insulin doses. Across studies, empagliflozin was generally well tolerated with a similar rate of hypoglycemia to placebo; however, patients had a slightly increased frequency of genital infections, but not urinary tract infections, versus placebo. Phase III studies have also reported a good safety profile along with significant improvements in HbA1c, weight and blood pressure, with no increased risk of hypoglycemia versus placebo. Based on available data, it appears that empagliflozin may be a useful option in a range of patients; however, clinical decisions will be better informed by the results of ongoing studies, in particular, a large cardiovascular outcome study (EMPA-REG OUTCOME™.

  4. Sodium-glucose cotransporter-2 inhibitors and cardiovascular outcomes in type 2 diabetes mellitus: A systematic review

    Directory of Open Access Journals (Sweden)

    Ziad G Nasr

    2017-01-01

    Full Text Available Sodium-glucose cotransporter - 2 (SGLT2 inhibitors are a novel class of anti-diabetics proven to reduce blood pressure, blood glucose and body weight. However, the long-term cardiovascular (CV safety implications of these agents remain unclear. This systematic review aimed to evaluate the available clinical trial evidence pertaining to long-term cardiovascular safety of SGLT2 inhibitors. The databases EMBASE and MEDLINE were searched. Randomized controlled trials assessing CV safety of SGLT2 inhibitors compared with placebo or anti-diabetic medications were included. Two investigators independently extracted study data and completed risk of bias assessments (sequence generation, allocation concealment, blinding, incomplete outcome data, or selective outcome reporting and other biases. Outcomes included CV death, myocardial infarction, and stroke. A total of 464 studies were identified in the electronic search and 14 from other sources. Sixteen randomized clinical trials were included after full-text review. All studies reported at least one of the pre-defined outcomes (CV death, myocardial infarction, and stroke. Nineteen CV deaths were reported in SGLT2 inhibitors groups versus 10 CV deaths in placebo or other comparator arms; numerically higher in the dapagliflozin arms. The number of CV events was numerically higher in SGLT2 inhibitor groups than in other arms. Risk of bias assessment showed mixed results, with overall quality assessments deemed unclear for 6 of 16 studies (37.5%. Findings showed CV outcomes do occur in patients taking SGLT2 inhibitors yet the clinical significance remains unclear. These results can be considered hypothesis generating, as studies were limited by inadequate power and/or follow-up time. Future longitudinal studies are needed to further assess the efficacy and safety profiles of these new agents before they become widely adopted in clinical practice.

  5. Sodium Glucose Cotransporter 2 (SGLT2 Plays as a Physiological Glucose Sensor and Regulates Cellular Contractility in Rat Mesangial Cells.

    Directory of Open Access Journals (Sweden)

    Masanori Wakisaka

    Full Text Available Mesangial cells play an important role in regulating glomerular filtration by altering their cellular tone. We report the presence of a sodium glucose cotransporter (SGLT in rat mesangial cells. This study in rat mesangial cells aimed to evaluate the expression and role of SGLT2.The SGLT2 expression in rat mesangial cells was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR. Changes in the mesangial cell surface area at different glucose concentrations and the effects of extracellular Na+ and Ca2+ and of SGLT and Na+/Ca2+ exchanger (NCX inhibitors on cellular size were determined. The cellular sizes and the contractile response were examined during a 6-day incubation with high glucose with or without phlorizin, an SGLT inhibitor.Western blotting revealed an SGLT2 band, and RT-PCR analysis of SGLT2 revealed the predicted 422-bp band in both rat mesangial and renal proximal tubular epithelial cells. The cell surface area changed according to the extracellular glucose concentration. The glucose-induced contraction was abolished by the absence of either extracellular Na+ or Ca2+ and by SGLT and NCX inhibitors. Under the high glucose condition, the cell size decreased for 2 days and increased afterwards; these cells did not contract in response to angiotensin II, and the SGLT inhibitor restored the abolished contraction.These data suggest that SGLT2 is expressed in rat mesangial cells, acts as a normal physiological glucose sensor and regulates cellular contractility in rat mesangial cells.

  6. Tofogliflozin, a potent and highly specific sodium/glucose cotransporter 2 inhibitor, improves glycemic control in diabetic rats and mice.

    Science.gov (United States)

    Suzuki, Masayuki; Honda, Kiyofumi; Fukazawa, Masanori; Ozawa, Kazuharu; Hagita, Hitoshi; Kawai, Takahiro; Takeda, Minako; Yata, Tatsuo; Kawai, Mio; Fukuzawa, Taku; Kobayashi, Takamitsu; Sato, Tsutomu; Kawabe, Yoshiki; Ikeda, Sachiya

    2012-06-01

    Sodium/glucose cotransporter 2 (SGLT2) is the predominant mediator of renal glucose reabsorption and is an emerging molecular target for the treatment of diabetes. We identified a novel potent and selective SGLT2 inhibitor, tofogliflozin (CSG452), and examined its efficacy and pharmacological properties as an antidiabetic drug. Tofogliflozin competitively inhibited SGLT2 in cells overexpressing SGLT2, and K(i) values for human, rat, and mouse SGLT2 inhibition were 2.9, 14.9, and 6.4 nM, respectively. The selectivity of tofogliflozin toward human SGLT2 versus human SGLT1, SGLT6, and sodium/myo-inositol transporter 1 was the highest among the tested SGLT2 inhibitors under clinical development. Furthermore, no interaction with tofogliflozin was observed in any of a battery of tests examining glucose-related physiological processes, such as glucose uptake, glucose oxidation, glycogen synthesis, hepatic glucose production, glucose-stimulated insulin secretion, and glucosidase reactions. A single oral gavage of tofogliflozin increased renal glucose clearance and lowered the blood glucose level in Zucker diabetic fatty rats. Tofogliflozin also improved postprandial glucose excursion in a meal tolerance test with GK rats. In db/db mice, 4-week tofogliflozin treatment reduced glycated hemoglobin and improved glucose tolerance in the oral glucose tolerance test 4 days after the final administration. No blood glucose reduction was observed in normoglycemic SD rats treated with tofogliflozin. These findings demonstrate that tofogliflozin inhibits SGLT2 in a specific manner, lowers blood glucose levels by increasing renal glucose clearance, and improves pathological conditions of type 2 diabetes with a low hypoglycemic potential.

  7. Evidence for the role of a Na(+)/HCO(3)(-) cotransporter in trout hepatocyte pHi regulation.

    Science.gov (United States)

    Furimsky, M; Moon, T W; Perry, S F

    2000-07-01

    The mechanisms of intracellular pH (pHi) regulation were examined in hepatocytes of the rainbow trout Oncorhynchus mykiss. pHi was monitored using the pH-sensitive fluorescent dye BCECF, and the effects of various media and pharmacological agents were examined for their influence on baseline pHi and recovery rates from acid and base loading. Rates of Na(+) uptake were measured using (22)Na, and changes in membrane potential were examined using the potentiometric fluorescent dye Oxonol VI. The rate of proton extrusion following acid loading was diminished by the blockade of either Na(+)/H(+) exchange (using amiloride) or anion transport (using DIDS). The removal of external HCO(3)(-) and the abolition of outward K(+) diffusion by the channel blocker Ba(2+) also decreased the rate of proton extrusion following acid load. Depolarization of the cell membrane with 50 mmol l(-)(1) K(+), however, did not affect pHi. The rate of recovery from base loading was significantly diminished by the blockade of anion transport, removal of external HCO(3)(-) and, to a lesser extent, by blocking Na(+)/H(+) exchange. The blockade of K(+) conductance had no effect. The decrease in Na(+) uptake rate observed in the presence of the anion transport blocker DIDS and the DIDS-sensitive hyperpolarization of membrane potential during recovery from acid loading suggest that a Na(+)-dependent electrogenic transport system is involved in the restoration of pHi after intracellular acidification. The effects on baseline pHi indicate that the different membrane exchangers are tonically active in the maintenance of steady-state pHi. This study confirms the roles of a Na(+)/H(+) exchanger and a Cl(-)/HCO(3)(-) exchanger in the regulation of trout hepatocyte pHi and provides new evidence that a Na(+)/HCO(3)(-) cotransporter contributes to pHi regulation.

  8. Role of Sodium Bicarbonate Cotransporters in Intracellular pH Regulation and Their Regulatory Mechanisms in Human Submandibular Glands.

    Science.gov (United States)

    Namkoong, Eun; Shin, Yong-Hwan; Bae, Jun-Seok; Choi, Seulki; Kim, Minkyoung; Kim, Nahyun; Hwang, Sung-Min; Park, Kyungpyo

    2015-01-01

    Sodium bicarbonate cotransporters (NBCs) are involved in the pH regulation of salivary glands. However, the roles and regulatory mechanisms among different NBC isotypes have not been rigorously evaluated. We investigated the roles of two different types of NBCs, electroneutral (NBCn1) and electrogenic NBC (NBCe1), with respect to pH regulation and regulatory mechanisms using human submandibular glands (hSMGs) and HSG cells. Intracellular pH (pHi) was measured and the pHi recovery rate from cell acidification induced by an NH4Cl pulse was recorded. Subcellular localization and protein phosphorylation were determined using immunohistochemistry and co-immunoprecipitation techniques. We determined that NBCn1 is expressed on the basolateral side of acinar cells and the apical side of duct cells, while NBCe1 is exclusively expressed on the apical membrane of duct cells. The pHi recovery rate in hSMG acinar cells, which only express NBCn1, was not affected by pre-incubation with 5 μM PP2, an Src tyrosine kinase inhibitor. However, in HSG cells, which express both NBCe1 and NBCn1, the pHi recovery rate was inhibited by PP2. The apparent difference in regulatory mechanisms for NBCn1 and NBCe1 was evaluated by artificial overexpression of NBCn1 or NBCe1 in HSG cells, which revealed that the pHi recovery rate was only inhibited by PP2 in cells overexpressing NBCe1. Furthermore, only NBCe1 was significantly phosphorylated and translocated by NH4Cl, which was inhibited by PP2. Our results suggest that both NBCn1 and NBCe1 play a role in pHi regulation in hSMG acinar cells, and also that Src kinase does not regulate the activity of NBCn1.

  9. Expression of three isoforms of Na-K-2Cl cotransporter (NKCC2) in the kidney and regulation by dehydration.

    Science.gov (United States)

    Itoh, Kazuko; Izumi, Yuichiro; Inoue, Takeaki; Inoue, Hideki; Nakayama, Yushi; Uematsu, Takayuki; Fukuyama, Takashi; Yamazaki, Taiga; Yasuoka, Yukiko; Makino, Takeshi; Nagaba, Yasushi; Tomita, Kimio; Kobayashi, Noritada; Kawahara, Katsumasa; Mukoyama, Masashi; Nonoguchi, Hiroshi

    2014-10-24

    Sodium reabsorption via Na-K-2Cl cotransporter 2 (NKCC2) in the thick ascending limbs has a major role for medullary osmotic gradient and subsequent water reabsorption in the collecting ducts. We investigated intrarenal localization of three isoforms of NKCC2 mRNA expressions and the effects of dehydration on them in rats. To further examine the mechanisms of dehydration, the effects of hyperosmolality on NKCC2 mRNA expression in microdissected renal tubules was studied. RT-PCR and RT-competitive PCR were employed. The expressions of NKCC2a and b mRNA were observed in the cortical thick ascending limbs (CAL) and the distal convoluted tubules (DCT) but not in the medullary thick ascending limbs (MAL), whereas NKCC2f mRNA expression was seen in MAL and CAL. Two-day dehydration did not affect these mRNA expressions. In contrast, hyperosmolality increased NKCC2 mRNA expression in MAL in vitro. Bradykinin dose-dependently decreased NKCC2 mRNA expression in MAL. However, dehydration did not change NKCC2 protein expression in membrane fraction from cortex and outer medulla and in microdissected MAL. These data show that NKCC2a/b and f types are mainly present in CAL and MAL, respectively. Although NKCC2 mRNA expression was stimulated by hyperosmolality in vitro, NKCC2 mRNA and protein expressions were not stimulated by dehydration in vivo. These data suggest the presence of the inhibitory factors for NKCC2 expression in dehydration. Considering the role of NKCC2 for the countercurrent multiplier system, NKCC2f expressed in MAL might be more important than NKCC2a/b. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats.

    Science.gov (United States)

    Walsh, Kathryn R; Kuwabara, Jill T; Shim, Joon W; Wainford, Richard D

    2016-01-15

    Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension. Copyright © 2016 the American Physiological Society.

  11. K-Cl Cotransporter 2-mediated Cl- Extrusion Determines Developmental Stage-dependent Impact of Propofol Anesthesia on Dendritic Spines.

    Science.gov (United States)

    Puskarjov, Martin; Fiumelli, Hubert; Briner, Adrian; Bodogan, Timea; Demeter, Kornel; Lacoh, Claudia-Marvine; Mavrovic, Martina; Blaesse, Peter; Kaila, Kai; Vutskits, Laszlo

    2017-05-01

    General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABAA)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABAA)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. The KCC2-dependent developmental increase in the efficacy of GABAA-mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

  12. Euglycemic Diabetic Ketoacidosis with Elevated Acetone in a Patient Taking a Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitor.

    Science.gov (United States)

    Andrews, Tory J; Cox, Robert D; Parker, Christina; Kolb, James

    2017-02-01

    Sodium-glucose cotransporter-2 (SGLT2) inhibitor medications are a class of antihyperglycemic agents that increase urinary glucose excretion by interfering with the reabsorption of glucose in the proximal renal tubules. In May of 2015, the U.S. Food and Drug Administration released a warning concerning a potential increased risk of ketoacidosis and ketosis in patients taking these medications. We present a case of a 57-year-old woman with type 2 diabetes mellitus taking a combination of canagliflozin and metformin who presented with progressive altered mental status over the previous 2 days. Her work-up demonstrated a metabolic acidosis with an anion gap of 38 and a venous serum pH of 7.08. The serum glucose was 168 mg/dL. The urinalysis showed glucose > 500 mg/dL and ketones of 80 mg/dL. Further evaluation demonstrated an elevated serum osmolality of 319 mOsm/kg and an acetone concentration of 93 mg/dL. She was treated with intravenous insulin and fluids, and the metabolic abnormalities and her altered mental status resolved within 36 h. This was the first episode of diabetic ketoacidosis (DKA) for this patient. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Diabetic patients on SGLT2 inhibitor medications are at risk for ketoacidosis. Due to the renal glucose-wasting properties of these drugs, they may present with ketoacidosis with only mild elevations in serum glucose, potentially complicating the diagnosis. Acetone is one of the three main ketone bodies formed during DKA and it may be present at considerable concentrations, contributing to the serum osmolality. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Age- and sex-dependent susceptibility to phenobarbital-resistant neonatal seizures: role of chloride co-transporters.

    Science.gov (United States)

    Kang, Seok Kyu; Markowitz, Geoffrey J; Kim, Shin Tae; Johnston, Michael V; Kadam, Shilpa D

    2015-01-01

    Ischemia in the immature brain is an important cause of neonatal seizures. Temporal evolution of acquired neonatal seizures and their response to anticonvulsants are of great interest, given the unreliability of the clinical correlates and poor efficacy of first-line anti-seizure drugs. The expression and function of the electroneutral chloride co-transporters KCC2 and NKCC1 influence the anti-seizure efficacy of GABAA-agonists. To investigate ischemia-induced seizure susceptibility and efficacy of the GABAA-agonist phenobarbital (PB), with NKCC1 antagonist bumetanide (BTN) as an adjunct treatment, we utilized permanent unilateral carotid-ligation to produce acute ischemic-seizures in post-natal day 7, 10, and 12 CD1 mice. Immediate post-ligation video-electroencephalograms (EEGs) quantitatively evaluated baseline and post-treatment seizure burdens. Brains were examined for stroke-injury and western blot analyses to evaluate the expression of KCC2 and NKCC1. Severity of acute ischemic seizures post-ligation was highest at P7. PB was an efficacious anti-seizure agent at P10 and P12, but not at P7. BTN failed as an adjunct, at all ages tested and significantly blunted PB-efficacy at P10. Significant acute post-ischemic downregulation of KCC2 was detected at all ages. At P7, males displayed higher age-dependent seizure susceptibility, associated with a significant developmental lag in their KCC2 expression. This study established a novel neonatal mouse model of PB-resistant seizures that demonstrates age/sex-dependent susceptibility. The age-dependent profile of KCC2 expression and its post-insult downregulation may underlie the PB-resistance reported in this model. Blocking NKCC1 with low-dose BTN following PB treatment failed to improve PB-efficacy.

  14. Role of an extracellular loop in determining the stoichiometry of Na+–HCO3− cotransporters

    Science.gov (United States)

    Chen, Li-Ming; Liu, Ying; Boron, Walter F

    2011-01-01

    The Na+–HCO3− cotransporters (NBCs) of the solute carrier 4 family (SLC4) are critical for regulating pH in cells as well as in fluids such as blood and cerebrospinal fluid. Moreover, mutations and gene disruptions in NBC are linked to a wide range of pathologies. NBCe1 (SLC4A4) is electrogenic because it has an apparent Na+:HCO3− stoichiometry of 1:2 or 1:3, whereas NBCn1 (SLC4A7) is electroneutral because it has an apparent stoichiometry of 1:1. Because stoichiometry influences the effect of transport on membrane potential and vice versa, a central question is what structural features underlie electrogenicity versus electroneutrality. A previous study on rat NBCe1/n1 chimeras demonstrated that the structural elements determining the electrogenicity of NBCe1-A are located within the transmembrane domain, excluding the large third extracellular loop. In the present study we generated a series of chimeras of human NBCe1-A and human NBCn1-A. We found that replacing merely the predicted fourth extracellular loop (EL4) – containing 32 amino acid residues that include 7 prolines – of human NBCe1-A with EL4 of NBCn1-A creates an electroneutral NBC. The opposite switch converts an electroneutral construct to one with electrogenic properties. The introduction of an N-glycosylation site into EL4 confirms that at least a part of it is exposed to the extracellular fluid. We hypothesize that putative EL4 either contributes to the substrate-binding vestibule or indirectly influences substrate binding by interacting with one or more transmembrane segments, thereby controlling the nature of transport. PMID:21224233

  15. Role of Sodium Bicarbonate Cotransporters in Intracellular pH Regulation and Their Regulatory Mechanisms in Human Submandibular Glands.

    Directory of Open Access Journals (Sweden)

    Eun Namkoong

    Full Text Available Sodium bicarbonate cotransporters (NBCs are involved in the pH regulation of salivary glands. However, the roles and regulatory mechanisms among different NBC isotypes have not been rigorously evaluated. We investigated the roles of two different types of NBCs, electroneutral (NBCn1 and electrogenic NBC (NBCe1, with respect to pH regulation and regulatory mechanisms using human submandibular glands (hSMGs and HSG cells. Intracellular pH (pHi was measured and the pHi recovery rate from cell acidification induced by an NH4Cl pulse was recorded. Subcellular localization and protein phosphorylation were determined using immunohistochemistry and co-immunoprecipitation techniques. We determined that NBCn1 is expressed on the basolateral side of acinar cells and the apical side of duct cells, while NBCe1 is exclusively expressed on the apical membrane of duct cells. The pHi recovery rate in hSMG acinar cells, which only express NBCn1, was not affected by pre-incubation with 5 μM PP2, an Src tyrosine kinase inhibitor. However, in HSG cells, which express both NBCe1 and NBCn1, the pHi recovery rate was inhibited by PP2. The apparent difference in regulatory mechanisms for NBCn1 and NBCe1 was evaluated by artificial overexpression of NBCn1 or NBCe1 in HSG cells, which revealed that the pHi recovery rate was only inhibited by PP2 in cells overexpressing NBCe1. Furthermore, only NBCe1 was significantly phosphorylated and translocated by NH4Cl, which was inhibited by PP2. Our results suggest that both NBCn1 and NBCe1 play a role in pHi regulation in hSMG acinar cells, and also that Src kinase does not regulate the activity of NBCn1.

  16. The sodium-bicarbonate cotransporter NBCe2 (slc4a5) expressed in human renal proximal tubules shows increased apical expression under high-salt conditions.

    Science.gov (United States)

    Gildea, John J; Xu, Peng; Carlson, Julia M; Gaglione, Robert T; Bigler Wang, Dora; Kemp, Brandon A; Reyes, Camellia M; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2015-12-01

    The electrogenic sodium bicarbonate cotransporter (NBCe2) is encoded by SLC4A5, variants of which have been associated with salt sensitivity of blood pressure, which affects 25% of the adult population. NBCe2 is thought to mediate sodium bicarbonate cotransport primarily in the renal collecting duct, but NBCe2 mRNA is also found in the rodent renal proximal tubule (RPT). The protein expression or function of NBCe2 has not been demonstrated in the human RPT. We validated an NBCe2 antibody by shRNA and Western blot analysis, as well as overexpression of an epitope-tagged NBCe2 construct in both RPT cells (RPTCs) and human embryonic kidney 293 (HEK293) cells. Using this validated NBCe2 antibody, we found NBCe2 protein expression in the RPT of fresh and frozen human kidney slices, RPTCs isolated from human urine, and isolated RPTC apical membrane. Under basal conditions, NBCe2 was primarily found in the Golgi, while NBCe1 was primarily found at the basolateral membrane. Following an acute short-term increase in intracellular sodium, NBCe2 expression was increased at the apical membrane in cultured slices of human kidney and polarized, immortalized RPTCs. Sodium bicarbonate transport was increased by monensin and overexpression of NBCe2, decreased by NBCe2 shRNA, but not by NBCe1 shRNA, and blocked by 2,2'-(1,2-ethenediyl)bis[5-isothiocyanato-benzenesulfonic acid]. NBCe2 could be important in apical sodium and bicarbonate cotransport under high-salt conditions; the implication of the ex vivo studies to the in vivo situation when salt intake is increased remains unclear. Therefore, future studies will examine the role of NBCe2 in mediating increased renal sodium transport in humans whose blood pressures are elevated by an increase in sodium intake. Copyright © 2015 the American Physiological Society.

  17. [Sodium-glucose co-transporter-2 inhibitors: from the bark of apple trees and familial renal glycosuria to the treatment of type 2 diabetes mellitus].

    Science.gov (United States)

    Mauricio, Dídac

    2013-09-01

    The therapeutic armamentarium for the treatment of hyperglycemia in type 2 diabetes mellitus is still inadequate. We are currently witnessing the introduction of a new mode of hypoglycemic treatment through induction of glycosuria to decrease the availability of the metabolic substrate, i.e. glucose. Clinical trials have shown that sodium-glucose co-transporter-2 (SGLT2) inhibitors are as efficacious as other oral hypoglycemic drugs. This article discusses the basic features of this new treatment concept and the efficacy and safety of this new drug group. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  18. Increased NBCn1 expression, Na+/ HCO 3 ? co-transport and intracellular pH in human vascular smooth muscle cells with a risk allele for hypertension

    OpenAIRE

    Ng, Fu Liang; Boedtkjer, Ebbe; Witkowska, Kate; Ren, Meixia; Zhang, Ruoxin; Tucker, Arthur; Aalkj?r, Christian; Caulfield, Mark J.; Ye, Shu

    2017-01-01

    Abstract Genome-wide association studies have revealed an association between variation at the SLC4A7 locus and blood pressure. SLC4A7 encodes the electroneutral Na+/ HCO 3 ? co-transporter NBCn1 which regulates intracellular pH (pH i ). We conducted a functional study of variants at this locus in primary cultures of vascular smooth muscle and endothelial cells. In both cell types, we found genotype-dependent differences for rs13082711 in DNA-nuclear protein interactions, where the risk allel...

  19. Vhc1, a novel transporter belonging to the family of electroneutral cation–Cl− cotransporters, participates in the regulation of cation content and morphology of Saccharomyces cerevisiae vacuoles

    Czech Academy of Sciences Publication Activity Database

    Petrezsélyová, Silvia; Kinclová-Zimmermannová, Olga; Sychrová, Hana

    2013-01-01

    Roč. 1828, č. 2 (2013), s. 623-631 ISSN 0005-2736 R&D Projects: GA AV ČR(CZ) IAA500110801; GA MŠk(CZ) LC531; GA MŠk(CZ) OC10012 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200110901 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : salt tolerance * yeast vacuole * potassium homeostasis * cation- chloride cotransport Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.431, year: 2013

  20. Synergy between scientific advancement and technological innovation, illustrated by a mechanism-based model characterizing sodium-glucose cotransporter-2 inhibition.

    Science.gov (United States)

    Zhang, Liping; Ng, Chee M; List, James F; Pfister, Marc

    2010-09-01

    Advances in experimental medicine and technological innovation during the past century have brought tremendous progress in modern medicine and generated an ever-increasing amount of data from bench and bedside. The desire to extend scientific knowledge motivates effective data integration. Technological innovation makes this possible, which in turn accelerates the advancement in science. This mutually beneficial interaction is illustrated by the development of an expanded mechanism-based model for understanding a novel mechanism, sodium-glucose cotransporter-2 SGLT2 inhibition for potential treatment of type 2 diabetes mellitus.

  1. Sodium glucose co-transporter 2 inhibitors: blocking renal tubular reabsorption of glucose to improve glycaemic control in patients with diabetes.

    Science.gov (United States)

    Jabbour, S A; Goldstein, B J

    2008-08-01

    The kidney plays a central role in the regulation of plasma glucose levels, although until recently this has not been widely appreciated or considered a target for therapeutic intervention. The sodium glucose co-transporter type 2 (SGLT2) located in the plasma membrane of cells lining the proximal tubule mediates the majority of renal glucose reabsorption from the tubular fluid, which normally prevents the loss of glucose in the urine. Competitive inhibitors of SGLT2 that provoke the renal excretion of glucose have been discovered, thereby providing a unique mechanism to potentially lower the elevated blood glucose levels in patients with diabetes. To explore the physiology of SGLT2 action and discuss several SGLT2 inhibitors that have entered early clinical development. All publicly available data were identified by searching the internet for 'SGLT2' and 'SGLT2 inhibitor' through 1 November 2007. Published articles, press releases and abstracts presented at national and international meetings were considered. Sodium glucose co-transporter type 2 inhibition is a novel treatment option for diabetes, which has been studied in preclinical models and a few potent and selective SGLT2 inhibitors have been reported and are currently in clinical development. These agents appear to be safe and generally well tolerated, and will potentially be a beneficial addition to the growing battery of oral antihyperglycaemic agents.

  2. An Inverse Relationship Links Temperature and Substrate Apparent Affinity in the Ion-Coupled Cotransporters rGAT1 and KAAT1

    Directory of Open Access Journals (Sweden)

    Antonio Peres

    2012-11-01

    Full Text Available The effects of temperature on the operation of two ion-coupled cotransporters of the SLC6A family, namely rat GAT1 (SLC6A1 and KAAT1 (SLC6A19 from Manduca sexta, have been studied by electrophysiological means in Xenopus laevis oocytes expressing these proteins. The maximal transport-associated current (Imax and the apparent substrate affinity (K05 were measured. In addition to the expected increase in transport rate (Q10 = 3–6, both transporters showed greater K05 values (i.e., a decrease in apparent affinity at higher temperatures. The transport efficiency, estimated as Imax/K05, increased at negative potentials in both transporters, but did not show statistically significant differences with temperature. The observation that the apparent substrate affinity is inversely related to the transport rate suggests a kinetic regulation of this parameter. Furthermore, the present results indicate that the affinities estimated at room temperature for mammalian cotransporters may not be simply extrapolated to their physiological operating conditions.

  3. General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt

    KAUST Repository

    Lacoh, Claudia Marvine

    2013-03-26

    BackgroundThe developmental transition from depolarizing to hyperpolarizing γ-aminobutyric acid-mediated neurotransmission is primarily mediated by an increase in the amount of the potassium-chloride cotransporter KCC2 during early postnatal life. However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study was to explore how these drugs affect KCC2 expression during the brain growth spurt.MethodsWistar rat pups were exposed to either a single dose or 6 h of midazolam, propofol, or ketamine anaesthesia at postnatal days 0, 5, 10, or 15. KCC2 expression was assessed using immunoblotting, immunohistochemistry, or quantitative polymerase chain reaction analysis up to 3 days post-exposure in the medial prefrontal cortex.ResultsThere was a progressive and steep increase in the expression of KCC2 between birth and 2 weeks of age. Exposure to midazolam, propofol, or ketamine up to 6 h at any investigated stages of the brain growth spurt did not influence the expression of this cotransporter protein.ConclusionI.V. general anaesthetics do not seem to influence developmental expression of KCC2 during the brain growth spurt. © 2013 © The Author [2013].

  4. Sodium-glucose cotransporter 2 inhibitors combined with dipeptidyl peptidase-4 inhibitors in the management of type 2 diabetes: a review of current clinical evidence and rationale

    Directory of Open Access Journals (Sweden)

    Yassin SA

    2017-03-01

    Full Text Available Sayf A Yassin,1 Vanita R Aroda2 1MedStar Union Memorial Hospital, Baltimore, 2MedStar Health Research Institute, Hyattsville, MD, USA Abstract: Type 2 diabetes mellitus (T2DM is a progressive and multifactorial cardiometabolic disorder. Almost half of adults with diabetes fail to achieve their recommended glucose control target. This has prompted some clinicians to advocate the use of more intensive initial therapy, including the use of combination therapy to target multiple physiologic defects in diabetes with the goal of achieving and sustaining glucose control. Numerous options exist for combining the various classes of glucose-lowering agents in the treatment of T2DM. This report reviews the mechanism, rationale, and evidence from clinical trials for combining two of the newer drug classes, namely, dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter 2 inhibitors, and considers the possible role of such dual therapy in the management of T2DM. Keywords: sodium-glucose cotransporter 2 inhibitors, dipeptidyl peptidase-4 inhibitors, type 2 diabetes mellitus, combination therapy

  5. Activation of thiazide-sensitive co-transport by angiotensin II in the cyp1a1-Ren2 hypertensive rat.

    Directory of Open Access Journals (Sweden)

    Ali Ashek

    Full Text Available Transgenic rats with inducible expression of the mouse Ren2 gene were used to elucidate mechanisms leading to the development of hypertension and renal injury. Ren2 transgene activation was induced by administration of a naturally occurring aryl hydrocarbon, indole-3-carbinol (100 mg/kg/day by gastric gavage. Blood pressure and renal parameters were recorded in both conscious and anesthetized (butabarbital sodium; 120 mg/kg IP rats at selected time-points during the development of hypertension. Hypertension was evident by the second day of treatment, being preceded by reduced renal sodium excretion due to activation of the thiazide-sensitive sodium-chloride co-transporter. Renal injury was evident after the first day of transgene induction, being initially limited to the pre-glomerular vasculature. Mircoalbuminuria and tubuloinsterstitial injury developed once hypertension was established. Chronic treatment with either hydrochlorothiazide or an AT1 receptor antagonist normalized sodium reabsorption, significantly blunted hypertension and prevented renal injury. Urinary aldosterone excretion was increased ≈ 20 fold, but chronic mineralocorticoid receptor antagonism with spironolactone neither restored natriuretic capacity nor prevented hypertension. Spironolactone nevertheless ameliorated vascular damage and prevented albuminuria. This study finds activation of sodium-chloride co-transport to be a key mechanism in angiotensin II-dependent hypertension. Furthermore, renal vascular injury in this setting reflects both barotrauma and pressure-independent pathways associated with direct detrimental effects of angiotensin II and aldosterone.

  6. X-ray diffraction studies on merohedrally twinned Δ1–62NtNBCe1-A crystals of the sodium/bicarbonate cotransporter

    International Nuclear Information System (INIS)

    Gill, Harindarpal S.; Dutcher, Lauren; Boron, Walter F.; Patel, Samir; Guay-Woodford, Lisa M.

    2013-01-01

    A truncated mutant missing the first 62 residues of the N-terminal, cytoplasmic domain of the sodium-bicarbonate NBCe1-A cotransporter crystallizes in space group P3 1 with pseudo-P3 1 21 symmetry and a hemihedral twin fraction of 33.0%. Twinned fractions and twin-pair statistics over binned resolutions confirm that the calculated twin fraction is associated with hemihedral twinning and not to non-crystallographic symmetry. NBCe1-A membrane-embedded macromolecules that cotransport sodium and bicarbonate ions across the bilayer serve to maintain acid–base homeostasis throughout the body. Defects result in a number of renal and eye disorders, including type-II renal tubular acidosis and cataracts. Here, crystals of a human truncated mutant of the cytoplasmic N-terminal domain of NBCe1 (Δ1–62NtNBCe1-A) are reported that diffract X-rays to 2.4 Å resolution. The crystal symmetry of Δ1–62NtNBCe1-A is of space group P3 1 with pseudo-P3 1 21 symmetry and it has a hemihedral twin fraction of 33.0%. The crystals may provide insight into the pathogenic processes observed in a subset of patients with truncating and point mutations in the gene encoding NBCe1

  7. Regulated phosphorylation of the K-Cl cotransporter KCC3 at dual C-terminal threonines is a potent switch of intracellular potassium content and cell volume homeostasis

    Directory of Open Access Journals (Sweden)

    Norma C. Adragna

    2015-07-01

    Full Text Available The defense of cell volume against excessive shrinkage or swelling is a requirement for cell function and organismal survival. Cell swelling triggers a coordinated homeostatic response termed regulatory volume decrease (RVD, resulting in K+ and Cl– efflux via the activation of K+ channels, volume-regulated anion channels (VRACs, and the K+-Cl– cotransporters, including KCC3. Here, we show genetic alanine (Ala substitution at threonines (Thr 991 and 1048 in the KCC3a isoform carboxyl-terminus, preventing inhibitory phosphorylation at these sites, not only significantly up-regulates KCC3a activity up to 25-fold in normally inhibitory isotonic conditions, but is also accompanied by reversal of activity of the related bumetanide-sensitive Na+-K+-2Cl– cotransporter isoform 1 (NKCC1. This results in a rapid (90 % reduction in intracellular K+ content (Ki via both Cl-dependent (KCC3a + NKCC1 and Cl-independent (DCPIB [VRAC inhibitor]-sensitive pathways, which collectively renders cells less prone to acute swelling in hypotonic osmotic stress. Together, these data demonstrate the phosphorylation state of Thr991/Thr1048 in the KCC3a encodes a potent switch of transporter activity, Ki homeostasis, and cell volume regulation, and reveal novel observations into the functional interaction among ion transport molecules involved in RVD.

  8. Regulated phosphorylation of the K-Cl cotransporter KCC3 is a molecular switch of intracellular potassium content and cell volume homeostasis.

    Science.gov (United States)

    Adragna, Norma C; Ravilla, Nagendra B; Lauf, Peter K; Begum, Gulnaz; Khanna, Arjun R; Sun, Dandan; Kahle, Kristopher T

    2015-01-01

    The defense of cell volume against excessive shrinkage or swelling is a requirement for cell function and organismal survival. Cell swelling triggers a coordinated homeostatic response termed regulatory volume decrease (RVD), resulting in K(+) and Cl(-) efflux via activation of K(+) channels, volume-regulated anion channels (VRACs), and the K(+)-Cl(-) cotransporters, including KCC3. Here, we show genetic alanine (Ala) substitution at threonines (Thr) 991 and 1048 in the KCC3a isoform carboxyl-terminus, preventing inhibitory phosphorylation at these sites, not only significantly up-regulates KCC3a activity up to 25-fold in normally inhibitory isotonic conditions, but is also accompanied by reversal of activity of the related bumetanide-sensitive Na(+)-K(+)-2Cl(-) cotransporter isoform 1 (NKCC1). This results in a rapid (90%) reduction in intracellular K(+) content (Ki) via both Cl-dependent (KCC3a + NKCC1) and Cl-independent [DCPIB (VRAC inhibitor)-sensitive] pathways, which collectively renders cells less prone to acute swelling in hypotonic osmotic stress. Together, these data demonstrate the phosphorylation state of Thr991/Thr1048 in KCC3a encodes a potent switch of transporter activity, Ki homeostasis, and cell volume regulation, and reveal novel observations into the functional interaction among ion transport molecules involved in RVD.

  9. Acute renal failure with sodium-glucose-cotransporter-2 inhibitors: Analysis of the FDA adverse event report system database.

    Science.gov (United States)

    Perlman, A; Heyman, S N; Matok, I; Stokar, J; Muszkat, M; Szalat, A

    2017-12-01

    Sodium-glucose-cotransporter-2 (SGLT2) inhibitors have recently been approved for the treatment of type II diabetes mellitus (T2DM). It has been proposed that these agents could induce acute renal failure (ARF) under certain conditions. This study aimed to evaluate the association between SGLT2-inhibitors and ARF in the FDA adverse event report system (FAERS) database. We analyzed adverse event cases submitted to FAERS between January 2013 and September 2016. ARF cases were identified using a structured medical query. Medications were identified using both brand and generic names. During the period evaluated, 18,915 reports (out of a total of 3,832,015 registered in FAERS) involved the use of SGLT2-inhibitors. SGLT2-inhibitors were reportedly associated with ARF in 1224 of these cases (6.4%), and were defined as the "primary" or "secondary" cause of the adverse event in 96.8% of these cases. The proportion of reports with ARF among reports with SGLT2 inhibitor was almost three-fold higher compared to reports without these drugs (ROR 2.88, 95% CI 2.71-3.05, p SGLT2-inhibitors was significantly greater than the proportion of ARF among cases with T2DM without SGLT2-inhibitors (ROR 1.68, 95% CI 1.57-1.8, p SGLT2-inhibitors, canagliflozin was associated with a higher proportion of reports of renal failure (7.3%), compared to empagliflozin and dapagliflozin (4.7% and 4.8% respectively, p SGLT2-inhibitors are associated with an increase in the proportion of reports of ARF compared to other medications. SGLT2-inhibitor agents may differ from one another in their respective risk for ARF. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  10. Epigenetic suppression of potassium-chloride co-transporter 2 expression in inflammatory pain induced by complete Freund's adjuvant (CFA).

    Science.gov (United States)

    Lin, C-R; Cheng, J-K; Wu, C-H; Chen, K-H; Liu, C-K

    2017-02-01

    Multiple mechanisms contribute to the stimulus-evoked pain hypersensitivity that may be experienced after peripheral inflammation. Persistent pathological stimuli in many pain conditions affect the expression of certain genes through epigenetic alternations. The main purpose of our study was to investigate the role of epigenetic modification on potassium-chloride co-transporter 2 (KCC2) gene expression in the persistence of inflammatory pain. Persistent inflammatory pain was induced through the injection of complete Freund's adjuvant (CFA) in the left hind paw of rats. Acetyl-histone H3 and H4 level was determined by chromatin immunoprecipitation in the spinal dorsal horn. Pain behaviour and inhibitory synaptic function of spinal cord were determined before and after CFA injection. KCC2 expression was determined by real time RT-PCR and Western blot. Intrathecal KCC2 siRNA (2 μg per 10 μL per rat) or HDAC inhibitor (10 μg per 10 μL per rat) was injected once daily for 3 days before CFA injection. Persistent inflammatory pain epigenetically suppressed KCC2 expression through histone deacetylase (HDAC)-mediated histone hypoacetylation, resulting in decreased inhibitory signalling efficacy. KCC2 knock-down caused by intrathecal administration of KCC2 siRNA in naïve rats reduced KCC2 expression in the spinal cord, leading to sensitized pain behaviours and impaired inhibitory synaptic transmission in their spinal cords. Moreover, intrathecal HDAC inhibitor injection in CFA rats increased KCC2 expression, partially restoring the spinal inhibitory synaptic transmission and relieving the sensitized pain behaviour. These findings suggest that the transcription of spinal KCC2 is regulated by histone acetylation epigenetically following CFA. Persistent pain suppresses KCC2 expression through HDAC-mediated histone hypoacetylation and consequently impairs the inhibitory function of inhibitory interneurons. Drugs such as HDAC inhibitors that suppress the influences of

  11. Volume regulation in mammalian skeletal muscle: the role of sodium-potassium-chloride cotransporters during exposure to hypertonic solutions.

    Science.gov (United States)

    Lindinger, Michael I; Leung, Matthew; Trajcevski, Karin E; Hawke, Thomas J

    2011-06-01

    Controversy exists as to whether mammalian skeletal muscle is capable of volume regulation in response to changes in extracellular osmolarity despite evidence that muscle fibres have the required ion transport mechanisms to transport solute and water in situ. We addressed this issue by studying the ability of skeletal muscle to regulate volume during periods of induced hyperosmotic stress using single, mouse extensor digitorum longus (EDL) muscle fibres and intact muscle (soleus and EDL). Fibres and intact muscles were loaded with the fluorophore, calcein, and the change in muscle fluorescence and width (single fibres only) used as a metric of volume change. We hypothesized that skeletal muscle exposed to increased extracellular osmolarity would elicit initial cellular shrinkage followed by a regulatory volume increase (RVI) with the RVI dependent on the sodium–potassium–chloride cotransporter (NKCC). We found that single fibres exposed to a 35% increase in extracellular osmolarity demonstrated a rapid, initial 27–32% decrease in cell volume followed by a RVI which took 10-20 min and returned cell volume to 90–110% of pre-stimulus values. Within intact muscle, exposure to increased extracellular osmolarity of varying degrees also induced a rapid, initial shrinkage followed by a gradual RVI, with a greater rate of initial cell shrinkage and a longer time for RVI to occur with increasing extracellular tonicities. Furthermore, RVI was significantly faster in slow-twitch soleus than fast-twitch EDL. Pre-treatment of muscle with bumetanide (NKCC inhibitor) or ouabain (Na+,K+-ATPase inhibitor), increased the initial volume loss and impaired the RVI response to increased extracellular osmolarity indicating that the NKCC is a primary contributor to volume regulation in skeletal muscle. It is concluded that mouse skeletal muscle initially loses volume then exhibits a RVI when exposed to increases in extracellular osmolarity. The rate of RVI is dependent on the

  12. 21 CFR 522.163 - Betamethasone dipropionate and betamethasone sodium phosphate aqueous suspension.

    Science.gov (United States)

    2010-04-01

    ...) Conditions of use—(1) Dogs. (i) It is used as an aid in the control of pruritus associated with dermatoses... may induce the first stage of parturition when administered during the last trimester of pregnancy and may precipitate premature parturition followed by dystocia, fetal death, retained placenta, and...

  13. Reversed electrogenic sodium bicarbonate cotransporter 1 is the major acid loader during recovery from cytosolic alkalosis in mouse cortical astrocytes.

    Science.gov (United States)

    Theparambil, Shefeeq M; Naoshin, Zinnia; Thyssen, Anne; Deitmer, Joachim W

    2015-08-15

    The regulation of H(+) i from cytosolic alkalosis has generally been attributed to the activity of Cl(-) -coupled acid loaders/base extruders in most cell types, including brain cells. The present study demonstrates that outwardly-directed sodium bicarbonate cotransport via electrogenic sodium bicarbonate cotransporter 1 (NBCe1) mediates the major fraction of H(+) i regulation from cytosolic alkalosis in mouse cortical astrocytes. Cl(-) -coupled acid-loading transporters play only a minor role in the regulation of H(+) i from alkalosis in mouse cortical astrocytes. NBCe1-mediated H(+) i regulation from alkalosis was dominant, with the support of intracellular carbonic anhydrase II, even when the intra- and extracellular [HCO3 (-) ] was very low (sodium bicarbonate cotransporter 1 (NBCe1) and for carbonic anhydrase (CA) isoform II. An acute cytosolic alkalosis was induced by the removal of either CO2 /HCO3 (-) or butyric acid, and the subsequent acid loading was analysed by monitoring changes in cytosolic H(+) or Na(+) using ion-sensitive fluorescent dyes. We have identified that NBCe1 reverses during alkalosis and contributes more than 70% to the rate of recovery from alkalosis by extruding Na(+) and HCO3 (-) . After CA inhibition or in CAII-knockout (KO) cells, the rate of recovery was reduced by 40%, and even by 70% in the nominal absence of CO2 /HCO3 (-) . Increasing the extracellular K(+) concentration modulated the rate of acid loading in wild-type cells, but not in NBCe1-KO cells. Removing chloride had only a minor effect on the recovery from alkalosis. Reversal of NBCe1 by reducing pH/[HCO3 (-) ] was demonstrated in astrocytes and in Xenopus oocytes, in which human NBCe1 was heterologously expressed. The results obtained suggest that reversed NBCe1, supported by CAII activity, plays a major role in acid-loading cortical astrocytes to support recovery from cytosolic alkalosis. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  14. Using Bacterial Surrogates to Assess Pathogen Transport in the Subsurface: Laboratory and Field Indications of Co-Transport Considerations

    Science.gov (United States)

    Emelko, M.; Stimson, J. R.; McLellan, N. L.; Mesquita, M.

    2009-12-01

    processes such as RBF. Here, duplicate column studies were conducted to evaluate the transport of nano- and micro-sized polystyrene micropsheres, aerobic spores of Bacillus subtilis, PR772 bacteriophage, and pathogenic Salmonella typhimurium bacteria in a well-sorted fine sand (d 50 = 0.6 mm). A field validation experiment investigating transport of 1.5 µm polystyrene micropsheres and aerobic spores in and RBF system comprised of unconsolidated silty sand, gravel, and boulders was conducted. The column studies demonstrated that the presence of the aerobic spores resulted in increased removal of 4.5 µm microspheres from< 2 log to ~4 log, and 1.5 µm microsphere removal from <0.5 log to ~1 log removal. Microscopic examination of the samples also revealed extensive clumping of microspheres and microorganisms during the experiments conducted with aerobic spores. A field trial during which microspheres and spores of B. subtilis were injected into the subsurface provided corroborating evidence of a co-transport effect of aerobic spores by demonstrating ~1.6 log increase in 1.5 µm microsphere removal in the presence of aerobic spores.

  15. Sodium bicarbonate cotransporter NBCe2 gene variants increase sodium and bicarbonate transport in human renal proximal tubule cells.

    Science.gov (United States)

    Gildea, John J; Xu, Peng; Kemp, Brandon A; Carlson, Julia M; Tran, Hanh T; Bigler Wang, Dora; Langouët-Astrié, Christophe J; McGrath, Helen E; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2018-01-01

    Salt sensitivity of blood pressure affects >30% of the hypertensive and >15% of the normotensive population. Variants of the electrogenic sodium bicarbonate cotransporter NBCe2 gene, SLC4A5, are associated with increased blood pressure in several ethnic groups. SLC4A5 variants are also highly associated with salt sensitivity, independent of hypertension. However, little is known about how NBCe2 contributes to salt sensitivity, although NBCe2 regulates renal tubular sodium bicarbonate transport. We hypothesized that SLC4A5 rs10177833 and rs7571842 increase NBCe2 expression and human renal proximal tubule cell (hRPTC) sodium transport and may be a cause of salt sensitivity of blood pressure. To characterize the hRPTC ion transport of wild-type (WT) and homozygous variants (HV) of SLC4A5. The expressions of NBCe2 mRNA and protein were not different between hRPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, luminal to basolateral sodium transport, NHE3 protein, and Cl-/HCO3- exchanger activity in hRPTCs were higher in HV than WT SLC4A5. Increasing intracellular sodium enhanced the apical location of NBCe2 in HV hRPTCs (4.24±0.35% to 11.06±1.72% (P<0.05, N = 3, 2-way ANOVA, Holm-Sidak test)) as determined by Total Internal Reflection Fluorescence Microscopy (TIRFM). In hRPTCs isolated from kidney tissue, increasing intracellular sodium enhanced bicarbonate-dependent pH recovery rate and increased NBCe2 mRNA and protein expressions to a greater extent in HV than WT SLC4A5 (+38.00±6.23% vs HV normal salt (P<0.01, N = 4, 2-way ANOVA, Holm-Sidak test)). In hRPTCs isolated from freshly voided urine, bicarbonate-dependent pH recovery was also faster in those from salt-sensitive and carriers of HV SLC4A5 than from salt-resistant and carriers of WT SLC4A5. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was normalized by SLC4A5- but not SLC4A4-shRNA. The binding of purified hepatocyte

  16. X-ray diffraction studies on merohedrally twinned Δ1-62NtNBCe1-A crystals of the sodium/bicarbonate cotransporter.

    Science.gov (United States)

    Gill, Harindarpal S; Dutcher, Lauren; Boron, Walter F; Patel, Samir; Guay-Woodford, Lisa M

    2013-07-01

    NBCe1-A membrane-embedded macromolecules that cotransport sodium and bicarbonate ions across the bilayer serve to maintain acid-base homeostasis throughout the body. Defects result in a number of renal and eye disorders, including type-II renal tubular acidosis and cataracts. Here, crystals of a human truncated mutant of the cytoplasmic N-terminal domain of NBCe1 (Δ1-62NtNBCe1-A) are reported that diffract X-rays to 2.4 Å resolution. The crystal symmetry of Δ1-62NtNBCe1-A is of space group P31 with pseudo-P3121 symmetry and it has a hemihedral twin fraction of 33.0%. The crystals may provide insight into the pathogenic processes observed in a subset of patients with truncating and point mutations in the gene encoding NBCe1.

  17. Physiology and pathophysiology of Na+/H+ exchange and Na+-K+-2Cl- cotransport in the heart, brain, and blood

    DEFF Research Database (Denmark)

    Pedersen, S. F.; O´Donnell, M. E.; Anderson, S. E.

    2006-01-01

    Maintenance of a stable cell volume and intracellular pH is critical for normal cell function. Arguably, two of the most important ion transporters involved in these processes are the Na+/H+ exchanger isoform 1 (NHE1) and Na+-K+-2Cl- cotransporter isoform 1 (NKCC1). Both NHE1 and NKCC1....... The aim is to provide a comprehensive overview of the mechanisms and consequences of stress-induced stimulation of these transporters with focus on the heart, brain, and blood. The physiological stressors reviewed are metabolic/exercise stress, osmotic stress, and mechanical stress, conditions in which...... are stimulated by cell shrinkage and by numerous other stimuli, including a wide range of hormones and growth factors, and for NHE1, intracellular acidification. Both transporters can be important regulators of cell volume, yet their activity also, directly or indirectly, affects the intracellular concentrations...

  18. In vitro characterization of luseogliflozin, a potent and competitive sodium glucose co-transporter 2 inhibitor: Inhibition kinetics and binding studies

    Directory of Open Access Journals (Sweden)

    Saeko Uchida

    2015-05-01

    Full Text Available In this study, we evaluated an inhibition model of luseogliflozin on sodium glucose co-transporter 2 (SGLT2. We also analyzed the binding kinetics of the drug to SGLT2 protein using [3H]-luseogliflozin. Luseogliflozin competitively inhibited human SGLT2 (hSGLT2-mediated glucose uptake with a Ki value of 1.10 nM. In the absence of glucose, [3H]-luseogliflozin exhibited a high affinity for hSGLT2 with a Kd value of 1.3 nM. The dissociation half-time was 7 h, suggesting that luseogliflozin dissociates rather slowly from hSGLT2. These profiles of luseogliflozin might contribute to the long duration of action of this drug.

  19. Substrate specificity of the electrogenic sodium/bicarbonate cotransporter NBCe1-A (SLC4A4, variant A) from humans and rabbits.

    Science.gov (United States)

    Lee, Seong-Ki; Boron, Walter F; Parker, Mark D

    2013-04-01

    In the basolateral membrane of proximal-tubule cells, NBCe1-A (SLC4A4, variant A), operating with an apparent Na(+):HCO(3)(-) stoichiometry of 1:3, contributes to the reclamation of HCO(3)(-) from the glomerular filtrate, thereby preventing whole body acidosis. Others have reported that NBCe1-like activity in human, rabbit, and rat renal preparations is substantially influenced by lithium, sulfite, oxalate, and harmaline. These data were taken as evidence for the presence of distinct Na(+) and CO(3)(2-) binding sites in NBCe1-A, favoring a model of 1 Na(+):1 HCO(3)(-):1 CO(3)(2-). Here, we reexamine these findings by expressing human or rabbit NBCe1-A clones in Xenopus oocytes. In oocytes, NBCe1-A exhibits a 1:2 stoichiometry and could operate in one of five thermodynamically equivalent transport modes: 1) cotransport of Na(+) + 2 HCO(3)(-), 2) cotransport of Na(+) + CO(3)(2-), 3) transport of NaCO(3)(-), 4) exchange of Na(+) + HCO(3)(-) for H(+), or 5) HCO(3)(-)-activated exchange of Na(+) for 2 H(+). In contrast to the behavior of NBCe1-like activity in renal preparations, we find that cloned NBCe1-A is only slightly stimulated by Li(+), not at all influenced by sulfite or oxalate, and only weakly inhibited by harmaline. These negative data do not uniquely support any of the five models above. In addition, we find that NBCe1-A mediates a small amount of Na(+)-independent NO(3)(-) transport and that NBCe1-A is somewhat inhibited by extracellular benzamil. We suggest that the features of NBCe1-like activity in renal preparations are influenced by yet-to-be-identified renal factors. Thus the actual ionic substrates of NBCe1 remain to be identified.

  20. The Role of Na:K:2Cl Cotransporter 1 (NKCC1/SLC12A2) in Dental Epithelium during Enamel Formation in Mice

    Science.gov (United States)

    Jalali, Rozita; Lodder, Johannes C.; Zandieh-Doulabi, Behrouz; Micha, Dimitra; Melvin, James E.; Catalan, Marcelo A.; Mansvelder, Huibert D.; DenBesten, Pamela; Bronckers, Antonius

    2017-01-01

    Na+:K+:2Cl− cotransporters (NKCCs) belong to the SLC12A family of cation-coupled Cl− transporters. We investigated whether enamel-producing mouse ameloblasts express NKCCs. Transcripts for Nkcc1 were identified in the mouse dental epithelium by RT-qPCR and NKCC1 protein was immunolocalized in outer enamel epithelium and in the papillary layer but not the ameloblast layer. In incisors of Nkcc1-null mice late maturation ameloblasts were disorganized, shorter and the mineral density of the enamel was reduced by 10% compared to wild-type controls. Protein levels of gap junction protein connexin 43, Na+-dependent bicarbonate cotransporter e1 (NBCe1), and the Cl−-dependent bicarbonate exchangers SLC26A3 and SLC26A6 were upregulated in Nkcc1-null enamel organs while the level of NCKX4/SLC24A4, the major K+, Na+ dependent Ca2+ transporter in maturation ameloblasts, was slightly downregulated. Whole-cell voltage clamp studies on rat ameloblast-like HAT-7 cells indicated that bumetanide increased ion-channel activity conducting outward currents. Bumetanide also reduced cell volume of HAT-7 cells. We concluded that non-ameloblast dental epithelium expresses NKCC1 to regulate cell volume in enamel organ and provide ameloblasts with Na+, K+ and Cl− ions required for the transport of mineral- and bicarbonate-ions into enamel. Absence of functional Nkcc1 likely is compensated by other types of ion channels and ion transporters. The increased amount of Cx43 in enamel organ cells in Nkcc1-null mice suggests that these cells display a higher number of gap junctions to increase intercellular communication. PMID:29209227

  1. Essential role of the electroneutral Na+-HCO3- cotransporter NBCn1 in murine duodenal acid-base balance and colonic mucus layer build-up in vivo.

    Science.gov (United States)

    Singh, Anurag Kumar; Xia, Weiliang; Riederer, Brigitte; Juric, Marina; Li, Junhua; Zheng, Wen; Cinar, Ayhan; Xiao, Fang; Bachmann, Oliver; Song, Penghong; Praetorius, Jeppe; Aalkjaer, Christian; Seidler, Ursula

    2013-04-15

    Duodenal epithelial cells need efficient defence strategies during gastric acidification of the lumen, while colonic mucosa counteracts damage by pathogens by building up a bacteria-free adherent mucus layer. Transport of HCO3(-) is considered crucial for duodenal defence against acid as well as for mucus release and expansion, but the transport pathways involved are incompletely understood. This study investigated the significance of the electroneutral Na(+)-HCO3(-) cotransporter NBCn1 for duodenal defence against acid and colonic mucus release. NBCn1 was localized to the basolateral membrane of duodenal villous enterocytes and of colonic crypt cells, with predominant expression in goblet cells. Duodenal villous enterocyte intracellular pH was studied before and during a luminal acid load by two-photon microscopy in exteriorized, vascularly perfused, indicator (SNARF-1 AM)-loaded duodenum of isoflurane-anaesthetized, systemic acid-base-controlled mice. Acid-induced HCO3(-) secretion was measured in vivo by single-pass perfusion and pH-stat titration. After a luminal acid load, NBCn1-deficient duodenocytes were unable to recover rapidly from intracellular acidification and could not respond adequately with protective HCO3(-) secretion. In the colon, build-up of the mucus layer was delayed, and a decreased thickness of the adherent mucus layer was observed, suggesting that basolateral HCO3(-) uptake is essential for optimal release of mucus. The electroneutral Na(+)-HCO3(-) cotransporter NBCn1 displays a differential cellular distribution in the murine intestine and is essential for HCO3(-)-dependent mucosal protective functions, such as recovery of intracellular pH and HCO3(-) secretion in the duodenum and secretion of mucus in the colon.

  2. Phosphorylation and transport in the Na-K-2Cl cotransporters, NKCC1 and NKCC2A, compared in HEK-293 cells.

    Directory of Open Access Journals (Sweden)

    Anke Hannemann

    2011-03-01

    Full Text Available Na-K-2Cl cotransporters help determine cell composition and volume. NKCC1 is widely distributed whilst NKCC2 is only found in the kidney where it plays a vital role reabsorbing 20% of filtered NaCl. NKCC2 regulation is poorly understood because of its restricted distribution and difficulties with its expression in mammalian cell cultures. Here we compare phosphorylation of the N-termini of the cotransporters, measured with phospho-specific antibodies, with bumetanide-sensitive transport of K(+ ((86Rb(+ (activity in HEK-293 cells stably expressing fNKCC1 or fNKCC2A which were cloned from ferret kidney. Activities of transfected transporters were distinguished from those of endogenous ones by working at 37 °C. fNKCC1 and fNKCC2A activities were highest after pre-incubation of cells in hypotonic low-[Cl(-] media to reduce cell [Cl(-] and volume during flux measurement. Phosphorylation of both transporters more than doubled. Pre-incubation with ouabain also strongly stimulated fNKCC1 and fNKCC2A and substantially increased phosphorylation, whereas pre-incubation in Na(+-free media maximally stimulated fNKCC1 and doubled its phosphorylation, but inhibited fNKCC2A, with a small increase in its phosphorylation. Kinase inhibitors halved phosphorylation and activity of both transporters whereas inhibition of phosphatases with calyculin A strongly increased phosphorylation of both transporters but only slightly stimulated fNKCC1 and inhibited fNCCC2A. Thus kinase inhibition reduced phosphorylation and transport, and transport stimulation was only seen when phosphorylation increased, but transport did not always increase with phosphorylation. This suggests phosphorylation of the N-termini determines the transporters' potential capacity to move ions, but final activity also depends on other factors. Transport cannot be reliably inferred solely using phospho-specific antibodies on whole-cell lysates.

  3. Phosphorylation and transport in the Na-K-2Cl cotransporters, NKCC1 and NKCC2A, compared in HEK-293 cells.

    Science.gov (United States)

    Hannemann, Anke; Flatman, Peter W

    2011-03-25

    Na-K-2Cl cotransporters help determine cell composition and volume. NKCC1 is widely distributed whilst NKCC2 is only found in the kidney where it plays a vital role reabsorbing 20% of filtered NaCl. NKCC2 regulation is poorly understood because of its restricted distribution and difficulties with its expression in mammalian cell cultures. Here we compare phosphorylation of the N-termini of the cotransporters, measured with phospho-specific antibodies, with bumetanide-sensitive transport of K(+) ((86)Rb(+)) (activity) in HEK-293 cells stably expressing fNKCC1 or fNKCC2A which were cloned from ferret kidney. Activities of transfected transporters were distinguished from those of endogenous ones by working at 37 °C. fNKCC1 and fNKCC2A activities were highest after pre-incubation of cells in hypotonic low-[Cl(-)] media to reduce cell [Cl(-)] and volume during flux measurement. Phosphorylation of both transporters more than doubled. Pre-incubation with ouabain also strongly stimulated fNKCC1 and fNKCC2A and substantially increased phosphorylation, whereas pre-incubation in Na(+)-free media maximally stimulated fNKCC1 and doubled its phosphorylation, but inhibited fNKCC2A, with a small increase in its phosphorylation. Kinase inhibitors halved phosphorylation and activity of both transporters whereas inhibition of phosphatases with calyculin A strongly increased phosphorylation of both transporters but only slightly stimulated fNKCC1 and inhibited fNCCC2A. Thus kinase inhibition reduced phosphorylation and transport, and transport stimulation was only seen when phosphorylation increased, but transport did not always increase with phosphorylation. This suggests phosphorylation of the N-termini determines the transporters' potential capacity to move ions, but final activity also depends on other factors. Transport cannot be reliably inferred solely using phospho-specific antibodies on whole-cell lysates.

  4. Role of Klotho in Osteoporosis and Renal Osteodystrophy

    Science.gov (United States)

    2014-10-01

    proximal tubules of the kidney. This is an important finding because prior to these data it was unclear how Fgf23 could downregulate the sodium phosphate...downregulates the sodium phosphate co-transporters (NaPi2a, Napi2c) and inhibits expression of 1α(OH)ase. We are interested in determining if there are any...7-day adaptation phase to the casein diet without addition of adenine. Then 8-week old Prx1cre;Klotho fl/fl and Klotho fl/fl mice were randomized

  5. ROS activate KCl cotransport in nonadherent Ehrlich ascites cells but K+ and Cl- channels in adherent Ehrlich Lettré and NIH3T3 cells

    DEFF Research Database (Denmark)

    Lambert, Ian Henry; Klausen, Thomas Kjær; Bergdahl, Andreas

    2009-01-01

    Addition of H2O2 (0.5 mM) to Ehrlich ascites tumor cells under isotonic conditions results within 25 min in a substantial (22 +/- 1 %) reduction in cell volume. The cell shrinkage is paralleled by net loss of K(+), which was significant within 8 min, whereas no concomitant increase in the K......(+) or Cl(-) conductances could be observed. The H2O2-induced cell shrinkage was unaffected by the presence of clofilium and clotrimazole, that block volume-sensitive and Ca(2+)-activated K(+) channels, respectively, and unaffected by a raise in extracellular K(+) concentration to a value which eliminates...... the electrochemical driving force for K(+). On the other hand, the H2O2-induced cell shrinkage was impaired in the presence of the KCl cotransport inhibitor DIOA, following substitution of NO3(-) for Cl(-), and when the driving force for KCl cotransport was omitted. It is suggested that H2O2 activates electro neutral...

  6. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman’s capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium

    OpenAIRE

    Tabatabai, Niloofar M.; North, Paula E.; Regner, Kevin R.; Kumar, Suresh N.; Duris, Christine B.; Blodgett, Amy B.

    2014-01-01

    In kidney nephron, parietal epithelial cells line the Bowman’s capsule and function as a permeability barrier for the glomerular filtrate. Bowman’s capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman’s capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane of epithelial cells in the...

  7. [Computation of the K+, Na+ and Cl- fluxes through plasma membrane of animal cell with Na+/K+ pump, NKCC, NC cotransporters, and ionic channels with and without non-Goldman rectification in K+ channels. Norma and apoptosis].

    Science.gov (United States)

    Rubashkin, A A; Iurinskaia, V E; Vereninov, A A

    2010-01-01

    The balance of K+, Na+ and Cl- fluxes through cell membrane with the Na+/K+ pump, ion channels and NKCC and NC cotransporters is considered. It is shown that all unidirectional K+, Na+ and Cl- fluxes through cell membrane, permeability coefficients of ion channels and membrane potential can be computed for balanced ion distribution between cell and the medium if K+, Na+ and Cl- concentration in cell water and three fluxes are known: total Cl- flux, total K+ influx and ouabain-inhibitable "pump" component of the K+ influx. Changes in the mortovalent ion balance in lymphoid cells U937 induced to apoptosis by 1 microM staurosporine are analyzed as an example. It is found that the apoptotic shift in ion and water balance in studied cells is caused by a decrease in the pump activity which is accompanied by a decrease in the integral permeability of Na+ channels without significant increase in K+ and Cl- channel permeabilities. Computation shows that only a small part of the total fluxes of K+, Na+ and Cl- accounts for the fluxes via NKCC and NC cotransporters. Therefore, cotransport fluxes can not be studied using inhibitors.

  8. Pharmacodynamics, efficacy and safety of sodium-glucose co-transporter type 2 (SGLT2) inhibitors for the treatment of type 2 diabetes mellitus.

    Science.gov (United States)

    Scheen, André J

    2015-01-01

    Inhibitors of sodium-glucose co-transporter type 2 (SGLT2) are proposed as a novel approach for the management of type 2 diabetes mellitus (T2DM). Several compounds are already available in many countries (dapagliflozin, canagliflozin, empagliflozin and ipragliflozin) and some others are in a late phase of development. The available SGLT2 inhibitors share similar pharmacokinetic characteristics, with a rapid oral absorption, a long elimination half-life allowing once-daily administration, an extensive hepatic metabolism mainly via glucuronidation to inactive metabolites, the absence of clinically relevant drug-drug interactions and a low renal elimination as parent drug. SGLT2 co-transporters are responsible for reabsorption of most (90 %) of the glucose filtered by the kidneys. The pharmacological inhibition of SGLT2 co-transporters reduces hyperglycaemia by decreasing renal glucose threshold and thereby increasing urinary glucose excretion. The amount of glucose excreted in the urine depends on both the level of hyperglycaemia and the glomerular filtration rate. Results of numerous placebo-controlled randomised clinical trials of 12-104 weeks duration have shown significant reductions in glycated haemoglobin (HbA1c), resulting in a significant increase in the proportion of patients reaching HbA1c targets, and a significant lowering of fasting plasma glucose when SGLT2 inhibitors were administered as monotherapy or in addition to other glucose-lowering therapies including insulin in patients with T2DM. In head-to-head trials of up to 2 years, SGLT2 inhibitors exerted similar glucose-lowering activity to metformin, sulphonylureas or sitagliptin. The durability of the glucose-lowering effect of SGLT2 inhibitors appears to be better; however, this remains to be more extensively investigated. The risk of hypoglycaemia was much lower with SGLT2 inhibitors than with sulphonylureas and was similarly low as that reported with metformin, pioglitazone or sitagliptin

  9. Interactions of [14C]phosphonoformic acid with renal cortical brush-border membranes. Relationship to the Na+-phosphate co-transporter

    International Nuclear Information System (INIS)

    Szczepanska-Konkel, M.; Yusufi, A.N.; Dousa, T.P.

    1987-01-01

    Since phosphonoformic acid (PFA) acts as a specific competitive inhibitor of Na+-Pi co-transport across renal brush-border membrane (BBM), we employed the [ 14 C]PFA as a probe to determine the mechanism of its interaction with rat renal BBM. The binding of [ 14 C]PFA to BBM vesicles (BBMV), with Na+ present in extravesicular medium (Na+o), was time- and temperature-dependent. The replacement of Na+o with other monovalent cations reduced the PFA binding by -80%. Cl- was the most effective accompanying monovalent anion as NaCl for maximum PFA binding. The Na+o increased the apparent affinity of BBMV for [ 14 C]PFA binding, but it did not change the maximum binding capacity. The maximum [ 14 C]PFA binding was achieved at Na+o approximately equal to 50 mM. The extent of Na+-dependent [ 14 C]PFA binding correlated with percent inhibition by an equimolar dose of PFA of the dependent BBMV uptake of 32Pi. Intravesicular Na+ (Na+i) decreased [ 14 C]PFA binding, on BBMV, and this inhibition by Na+i was dependent on the presence of Na+o. The increase in Na+i, at constant [Na+]o, decreased the Vmax, but not the Km, for [ 14 C]PFA binding on BBMV. Bound [ 14 C]PFA was displaced from BBMV by phosphonocarboxylic acids proportionally to their ability to inhibit gradient-dependent Pi transport, whereas other monophosphonates, diphosphonates, L-proline, or D-glucose did not influence the [ 14 C]PFA binding. The Na+-dependent binding of [ 14 C]PFA and of [ 3 H]phlorizin by BBMV was 10 times higher than binding of these ligands to renal basolateral membranes and to mitochondria. [ 14 C]PFA probably binds onto the same locus on the luminal surface of BBM, where Pi and Na+ form a ternary complex with the Na+-Pi co-transporter

  10. Involvement of the K+-Cl- co-transporter KCC2 in the sensitization to morphine-induced hyperlocomotion under chronic treatment with zolpidem in the mesolimbic system.

    Science.gov (United States)

    Shibasaki, Masahiro; Masukawa, Daiki; Ishii, Kazunori; Yamagishi, Yui; Mori, Tomohisa; Suzuki, Tsutomu

    2013-06-01

    Benzodiazepines are commonly used as sedatives, sleeping aids, and anti-anxiety drugs. However, chronic treatment with benzodiazepines is known to induce dependence, which is considered related to neuroplastic changes in the mesolimbic system. This study investigated the involvement of K(+) -Cl(-) co-transporter 2 (KCC2) in the sensitization to morphine-induced hyperlocomotion after chronic treatment with zolpidem [a selective agonist of γ-aminobutyric acid A-type receptor (GABAA R) α1 subunit]. In this study, chronic treatment with zolpidem enhanced morphine-induced hyperlocomotion, which is accompanied by the up-regulation of KCC2 in the limbic forebrain. We also found that chronic treatment with zolpidem induced the down-regulation of protein phosphatase-1 (PP-1) as well as the up-regulation of phosphorylated protein kinase C γ (pPKCγ). Furthermore, PP-1 directly associated with KCC2 and pPKCγ, whereas pPKCγ did not associate with KCC2. On the other hand, pre-treatment with furosemide (a KCC2 inhibitor) suppressed the enhancing effects of zolpidem on morphine-induced hyperlocomotion. These results suggest that the mesolimbic dopaminergic system could be amenable to neuroplastic change through a pPKCγ-PP-1-KCC2 pathway by chronic treatment with zolpidem. © 2013 International Society for Neurochemistry.

  11. Targeting Type 2 Diabetes with C-Glucosyl Dihydrochalcones as Selective Sodium Glucose Co-Transporter 2 (SGLT2) Inhibitors: Synthesis and Biological Evaluation.

    Science.gov (United States)

    Jesus, Ana R; Vila-Viçosa, Diogo; Machuqueiro, Miguel; Marques, Ana P; Dore, Timothy M; Rauter, Amélia P

    2017-01-26

    Inhibiting glucose reabsorption by sodium glucose co-transporter proteins (SGLTs) in the kidneys is a relatively new strategy for treating type 2 diabetes. Selective inhibition of SGLT2 over SGLT1 is critical for minimizing adverse side effects associated with SGLT1 inhibition. A library of C-glucosyl dihydrochalcones and their dihydrochalcone and chalcone precursors was synthesized and tested as SGLT1/SGLT2 inhibitors using a cell-based fluorescence assay of glucose uptake. The most potent inhibitors of SGLT2 (IC 50 = 9-23 nM) were considerably weaker inhibitors of SGLT1 (IC 50 = 10-19 μM). They showed no effect on the sodium independent GLUT family of glucose transporters, and the most potent ones were not acutely toxic to cultured cells. The interaction of a C-glucosyl dihydrochalcone with a POPC membrane was modeled computationally, providing evidence that it is not a pan-assay interference compound. These results point toward the discovery of structures that are potent and highly selective inhibitors of SGLT2.

  12. Ipragliflozin and other sodium-glucose cotransporter-2 (SGLT2) inhibitors in the treatment of type 2 diabetes: preclinical and clinical data.

    Science.gov (United States)

    Kurosaki, Eiji; Ogasawara, Hideaki

    2013-07-01

    Sodium-glucose cotransporter-2 (SGLT2) is expressed in the proximal tubules of the kidneys and plays a key role in renal glucose reabsorption. A novel class of antidiabetic medications, SGLT2-selective inhibitors attempt to improve glycemic control in diabetics by preventing glucose from being reabsorbed through SGLT2 and re-entering circulation. Ipragliflozin is an SGLT2 inhibitor in Phase 3 clinical development for the treatment of type 2 diabetes mellitus (T2DM). In this review, we summarize recent animal and human studies on ipragliflozin and other SGLT2 inhibitors including dapagliflozin, canagliflozin, empagliflozin, tofogliflozin, and luseogliflozin. These agents all show potent and selective SGLT2 inhibition in vitro and reduce blood glucose levels and HbA1c in both diabetic animal models and patients with T2DM. SGLT2 inhibitors offer several advantages over other classes of hypoglycemic agents. Due to their insulin-independent mode of action, SGLT2 inhibitors provide steady glucose control without major risk for hypoglycemia and may also reverse β-cell dysfunction and insulin resistance. Other favorable effects of SGLT2 inhibitors include a reduction in both body weight and blood pressure. SGLT2 inhibitors are safe and well tolerated and can easily be combined with other classes of antidiabetic medications to achieve tighter glycemic control. The long-term safety and efficacy of these agents are under evaluation. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Sodium-glucose cotransporter 2 (SGLT2) inhibitors and fracture risk in patients with type 2 diabetes mellitus: A meta-analysis.

    Science.gov (United States)

    Ruanpeng, Darin; Ungprasert, Patompong; Sangtian, Jutarat; Harindhanavudhi, Tasma

    2017-09-01

    Sodium-glucose cotransporter 2 (SGLT2) inhibitors could potentially alter calcium and phosphate homeostasis and may increase the risk of bone fracture. The current meta-analysis was conducted to investigate the fracture risk among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors. Randomized controlled trials that compared the efficacy of SGLT2 inhibitors to placebo were identified. The risk ratios of fracture among patients who received SGLT2 inhibitors versus placebo were extracted from each study. Pooled risk ratios and 95% confidence intervals were calculated using a random-effect, Mantel-Haenszel analysis. A total of 20 studies with 8286 patients treated with SGLT2 inhibitors were included. The pooled risk ratio of bone fracture in patients receiving SGLT2 inhibitors versus placebo was 0.67 (95% confidence interval, 0.42-1.07). The pooled risk ratio for canagliflozin, dapagliflozin, and empagliflozin was 0.66 (95% confidence interval, 0.37-1.19), 0.84 (95% confidence interval, 0.22-3.18), and 0.57 (95% confidence interval, 0.20-1.59), respectively. Increased risk of bone fracture among patients with type 2 diabetes mellitus treated with SGLT2 inhibitors compared with placebo was not observed in this meta-analysis. However, the results were limited by short duration of treatment/follow-up and low incidence of the event of interest. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Sodium-glucose co-transporter 2 inhibitors in addition to insulin therapy for management of type 2 diabetes mellitus: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Tang, Huilin; Cui, Wei; Li, Dandan; Wang, Tiansheng; Zhang, Jingjing; Zhai, Suodi; Song, Yiqing

    2017-01-01

    Given inconsistent trial results of sodium-glucose cotransporter 2 (SGLT2) inhibitors in addition to insulin therapy for treating type 2 diabetes mellitus (T2DM), a meta-analysis was performed to evaluate the efficacy and safety of this combination for T2DM by searching available randomized trials from PubMed, Embase, CENTRAL and ClinicalTrials.gov. Our meta-analysis included seven eligible placebo-controlled trials involving 4235 patients. Compared with placebo, SGLT2 inhibitor treatment was significantly associated with a mean reduction in HbA1c of -0.56%, fasting plasma glucose of -0.95 mmol/L, body weight of -2.63 kg and insulin dose of -8.79 IU, but an increased risk of drug-related adverse events by 36%, urinary tract infections by 29% and genital infections by 357%. No significant increase was observed in risk of overall adverse events [risk ratio (RR), 1.00], serious adverse events (RR, 0.90), adverse events leading to discontinuation (RR, 1.16), hypoglycaemia events (RR, 1.07) and severe hypoglycaemia events (RR, 1.24). No diabetic ketoacidosis events were reported. Further studies are needed to establish optimal combination type and dose. © 2016 John Wiley & Sons Ltd.

  15. Sodium-Glucose Linked Cotransporter-2 Inhibition Does Not Attenuate Disease Progression in the Rat Remnant Kidney Model of Chronic Kidney Disease.

    Directory of Open Access Journals (Sweden)

    Yanling Zhang

    Full Text Available Pharmacological inhibition of the proximal tubular sodium-glucose linked cotransporter-2 (SGLT2 leads to glycosuria in both diabetic and non-diabetic settings. As a consequence of their ability to modulate tubuloglomerular feedback, SGLT2 inhibitors, like agents that block the renin-angiotensin system, reduce intraglomerular pressure and single nephron GFR, potentially affording renoprotection. To examine this further we administered the SGLT2 inhibitor, dapagliflozin, to 5/6 (subtotally nephrectomised rats, a model of progressive chronic kidney disease (CKD that like CKD in humans is characterised by single nephron hyperfiltration and intraglomerular hypertension and where angiotensin converting enzyme inhibitors and angiotensin receptor blockers are demonstrably beneficial. When compared with untreated rats, both sham surgery and 5/6 nephrectomised rats that had received dapagliflozin experienced substantial glycosuria. Nephrectomised rats developed hypertension, heavy proteinuria and declining GFR that was unaffected by the administration of dapagliflozin. Similarly, SGLT2 inhibition did not attenuate the extent of glomerulosclerosis, tubulointerstitial fibrosis or overexpression of the profibrotic cytokine, transforming growth factor-ß1 mRNA in the kidneys of 5/6 nephrectomised rats. While not precluding beneficial effects in the diabetic setting, these findings indicate that SGLT2 inhibition does not have renoprotective effects in this classical model of progressive non-diabetic CKD.

  16. Na+-glucose cotransporter SGLT1 protein in salivary glands: potential involvement in the diabetes-induced decrease in salivary flow.

    Science.gov (United States)

    Sabino-Silva, R; Freitas, H S; Lamers, M L; Okamoto, M M; Santos, M F; Machado, U F

    2009-03-01

    Oral health complications in diabetes include decreased salivary secretion. The SLC5A1 gene encodes the Na(+)-glucose cotransporter SGLT1 protein, which not only transports glucose, but also acts as a water channel. Since SLC5A1 expression is altered in kidneys of diabetic subjects, we hypothesize that it could also be altered in salivary glands, contributing to diabetic dysfunction. The present study shows a diabetes-induced decrease (p salivary secretion, which was accompanied by enhanced (p diabetic rats revealed that SGLT1 protein expression increased in the luminal membrane of ductal cells, which can stimulate water reabsorption from primary saliva. Furthermore, SGLT1 protein was reduced in myoepithelial cells of the parotid from diabetic animals, and that, by reducing cellular contractile activity, might also be related to reduced salivary flux. Six-day insulin-treated diabetic rats reversed all alterations. In conclusion, diabetes increases SLC5A1 gene expression in salivary glands, increasing the SGLT1 protein content in the luminal membrane of ductal cells, which, by increasing water reabsorption, might explain the diabetes-induced decrease in salivary secretion.

  17. Do sodium-glucose co-transporter-2 inhibitors prevent heart failure with a preserved ejection fraction by counterbalancing the effects of leptin? A novel hypothesis.

    Science.gov (United States)

    Packer, Milton

    2018-06-01

    Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce the risk of serious heart failure events in patients with type 2 diabetes, but little is known about mechanisms that might mediate this benefit. The most common heart failure phenotype in type 2 diabetes is obesity-related heart failure with a preserved ejection fraction (HFpEF). It has been hypothesized that the synthesis of leptin in this disorder leads to sodium retention and plasma volume expansion as well as to cardiac and renal inflammation and fibrosis. Interestingly, leptin-mediated neurohormonal activation appears to enhance the expression of SGLT2 in the renal tubules, and SGLT2 inhibitors exert natriuretic actions at multiple renal tubular sites in a manner that can oppose the sodium retention produced by leptin. In addition, SGLT2 inhibitors reduce the accumulation and inflammation of perivisceral adipose tissue, thus minimizing the secretion of leptin and its paracrine actions on the heart and kidneys to promote fibrosis. Such fibrosis probably contributes to the impairment of cardiac distensibility and glomerular function that characterizes obesity-related HFpEF. Ongoing clinical trials with SGLT2 inhibitors in heart failure are positioned to confirm or refute the hypothesis that these drugs may favourably influence the course of obesity-related HFpEF by their ability to attenuate the secretion and actions of leptin. © 2018 John Wiley & Sons Ltd.

  18. Taurine Inhibits K+-Cl− Cotransporter KCC2 to Regulate Embryonic Cl− Homeostasis via With-no-lysine (WNK) Protein Kinase Signaling Pathway*

    Science.gov (United States)

    Inoue, Koichi; Furukawa, Tomonori; Kumada, Tatsuro; Yamada, Junko; Wang, Tianying; Inoue, Rieko; Fukuda, Atsuo

    2012-01-01

    GABA inhibits mature neurons and conversely excites immature neurons due to lower K+-Cl− cotransporter 2 (KCC2) expression. We observed that ectopically expressed KCC2 in embryonic cerebral cortices was not active; however, KCC2 functioned in newborns. In vitro studies revealed that taurine increased KCC2 inactivation in a phosphorylation-dependent manner. When Thr-906 and Thr-1007 residues in KCC2 were substituted with Ala (KCC2T906A/T1007A), KCC2 activity was facilitated, and the inhibitory effect of taurine was not observed. Exogenous taurine activated the with-no-lysine protein kinase 1 (WNK1) and downstream STE20/SPS1-related proline/alanine-rich kinase (SPAK)/oxidative stress response 1 (OSR1), and overexpression of active WNK1 resulted in KCC2 inhibition in the absence of taurine. Phosphorylation of SPAK was consistently higher in embryonic brains compared with that of neonatal brains and down-regulated by a taurine transporter inhibitor in vivo. Furthermore, cerebral radial migration was perturbed by a taurine-insensitive form of KCC2, KCC2T906A/T1007A, which may be regulated by WNK-SPAK/OSR1 signaling. Thus, taurine and WNK-SPAK/OSR1 signaling may contribute to embryonic neuronal Cl− homeostasis, which is required for normal brain development. PMID:22544747

  19. In silico analysis and experimental validation of azelastine hydrochloride (N4) targeting sodium taurocholate co-transporting polypeptide (NTCP) in HBV therapy.

    Science.gov (United States)

    Fu, L-L; Liu, J; Chen, Y; Wang, F-T; Wen, X; Liu, H-Q; Wang, M-Y; Ouyang, L; Huang, J; Bao, J-K; Wei, Y-Q

    2014-08-01

    The aim of this study was to explore sodium taurocholate co-transporting polypeptide (NTCP) exerting its function with hepatitis B virus (HBV) and its targeted candidate compounds, in HBV therapy. Identification of NTCP as a novel HBV target for screening candidate small molecules, was used by phylogenetic analysis, network construction, molecular modelling, molecular docking and molecular dynamics (MD) simulation. In vitro virological examination, q-PCR, western blotting and cytotoxicity studies were used for validating efficacy of the candidate compound. We used the phylogenetic analysis of NTCP and constructed its protein-protein network. Also, we screened compounds from Drugbank and ZINC, among which five were validated for their authentication in HepG 2.2.15 cells. Then, we selected compound N4 (azelastine hydrochloride) as the most potent of them. This showed good inhibitory activity against HBsAg (IC50 = 7.5 μm) and HBeAg (IC50 = 3.7 μm), as well as high SI value (SI = 4.68). Further MD simulation results supported good interaction between compound N4 and NTCP. In silico analysis and experimental validation together demonstrated that compound N4 can target NTCP in HepG2.2.15 cells, which may shed light on exploring it as a potential anti-HBV drug. © 2014 John Wiley & Sons Ltd.

  20. Effect of sodium-glucose cotransporter 2 (SGLT2) inhibition on weight loss is partly mediated by liver-brain-adipose neurocircuitry.

    Science.gov (United States)

    Sawada, Yoshikazu; Izumida, Yoshihiko; Takeuchi, Yoshinori; Aita, Yuichi; Wada, Nobuhiro; Li, EnXu; Murayama, Yuki; Piao, Xianying; Shikama, Akito; Masuda, Yukari; Nishi-Tatsumi, Makiko; Kubota, Midori; Sekiya, Motohiro; Matsuzaka, Takashi; Nakagawa, Yoshimi; Sugano, Yoko; Iwasaki, Hitoshi; Kobayashi, Kazuto; Yatoh, Shigeru; Suzuki, Hiroaki; Yagyu, Hiroaki; Kawakami, Yasushi; Kadowaki, Takashi; Shimano, Hitoshi; Yahagi, Naoya

    2017-11-04

    Sodium-glucose cotransporter 2 (SGLT2) inhibitors have both anti-diabetic and anti-obesity effects. However, the precise mechanism of the anti-obesity effect remains unclear. We previously demonstrated that the glycogen depletion signal triggers lipolysis in adipose tissue via liver-brain-adipose neurocircuitry. In this study, therefore, we investigated whether the anti-obesity mechanism of SGLT2 inhibitor is mediated by this mechanism. Diet-induced obese mice were subjected to hepatic vagotomy (HVx) or sham operation and loaded with high fat diet containing 0.015% tofogliflozin (TOFO), a highly selective SGLT2 inhibitor, for 3 weeks. TOFO-treated mice showed a decrease in fat mass and the effect of TOFO was attenuated in HVx group. Although both HVx and sham mice showed a similar level of reduction in hepatic glycogen by TOFO treatment, HVx mice exhibited an attenuated response in protein phosphorylation by protein kinase A (PKA) in white adipose tissue compared with the sham group. As PKA pathway is known to act as an effector of the liver-brain-adipose axis and activate triglyceride lipases in adipocytes, these results indicated that SGLT2 inhibition triggered glycogen depletion signal and actuated liver-brain-adipose axis, resulting in PKA activation in adipocytes. Taken together, it was concluded that the effect of SGLT2 inhibition on weight loss is in part mediated via the liver-brain-adipose neurocircuitry. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. The role of disease-linked residue glutamine-913 in support of the structure and function of the human electrogenic sodium/bicarbonate cotransporter NBCe1-A.

    Science.gov (United States)

    Myers, Evan J; Marshall, Aniko; Parker, Mark D

    2018-02-15

    Mutations in the sodium bicarbonate cotransporter NBCe1 (SLC4A4) cause proximal renal tubular acidosis (pRTA). We recently described a novel pRTA mutation p.Gln913Arg (Q913R), inherited in compound heterozygous form with p.Arg510His (R510H). Q913R causes intracellular retention of NBCe1 and a 'gain of function' Cl - leak. To learn more about the importance of glutamine at position 913, we substituted a variety of alternative amino-acid residues (Cys, Glu, Lys, Leu, Ser) at position 913. Studying cRNA-injected Xenopus oocytes by voltage clamp, we find that most de novo mutants exhibit close-to-normal NBCe1 activity; only Q913K expresses a Cl - leak. Studying transiently-transfected, polarised kidney cells by fluorescence microscopy we find that most de novo mutants (except Q913E) are intracellularly retained. A 3D homology model predicts that Gln913 is located in the gating domain of NBCe1 and neighbours the 3D space occupied by another pRTA-associated residue (Arg881), highlighting an important and conformationally-sensitive region of NBCe1. We conclude that the intracellular retention of Q913R is caused by the loss of Gln at position 913, but that the manifestation of the Cl - leak is related to the introduction of Arg at position 913. Our findings will inform future studies to elucidate the nature and the consequences of the leak.

  2. PDGF activates K-Cl cotransport through phosphoinositide 3-kinase and protein phosphatase-1 in primary cultures of vascular smooth muscle cells.

    Science.gov (United States)

    Zhang, Jing; Lauf, Peter K; Adragna, Norma C

    2005-07-15

    K-Cl cotransport (K-Cl COT, KCC) is an electroneutrally coupled movement of K and Cl present in most cells. In this work, we studied the pathways of regulation of K-Cl COT by platelet-derived growth factor (PDGF) in primary cultures of vascular smooth muscle cells (VSMCs). Wortmannin and LY 294002 blocked the PDGF-induced K-Cl COT activation, indicating that the phosphoinositide 3-kinase (PI 3-K) pathway is involved. However, PD 98059 had no effect on K-Cl COT activation by PDGF, suggesting that the mitogen-activated protein kinase pathway is not involved under the experimental conditions tested. Involvement of phosphatases was also examined. Sodium orthovanadate, cyclosporin A and okadaic acid had no effect on PDGF-stimulated K-Cl COT. Calyculin A blocked the PDGF-stimulated K-Cl COT by 60%, suggesting that protein phosphatase-1 (PP-1) is a mediator in the PDGF signaling pathway/s. In conclusion, our results indicate that the PDGF-mediated pathways of K-Cl COT regulation involve the signaling molecules PI 3-K and PP-1.

  3. Effect of Sodium-Glucose Co-Transporter 2 Inhibitor, Dapagliflozin, on Renal Renin-Angiotensin System in an Animal Model of Type 2 Diabetes.

    Science.gov (United States)

    Shin, Seok Joon; Chung, Sungjin; Kim, Soo Jung; Lee, Eun-Mi; Yoo, Young-Hye; Kim, Ji-Won; Ahn, Yu-Bae; Kim, Eun-Sook; Moon, Sung-Dae; Kim, Myung-Jun; Ko, Seung-Hyun

    2016-01-01

    Renal renin-angiotensin system (RAS) activation is one of the important pathogenic mechanisms in the development of diabetic nephropathy in type 2 diabetes. The aim of this study was to investigate the effects of a sodium-glucose co-transporter 2 (SGLT-2) inhibitor, dapagliflozin, on renal RAS in an animal model with type 2 diabetes. Dapagliflozin (1.0 mg/kg, OL-DA) or voglibose (0.6 mg/kg, OL-VO, diabetic control) (n = 10 each) was administered to Otsuka Long-Evans Tokushima Fatty (OLETF) rats for 12 weeks. We used voglibose, an alpha-glucosidase inhibitor, as a comparable counterpart to SGLT2 inhibitor because of its postprandial glucose-lowering effect without proven renoprotective effects. Control Long-Evans Tokushima Otsuka (LT) and OLETF (OL-C) rats received saline (n = 10, each). Changes in blood glucose, urine albumin, creatinine clearance, and oxidative stress were measured. Inflammatory cell infiltration, mesangial widening, and interstitial fibrosis in the kidney were evaluated by histological analysis. The effects of dapagliflozin on renal expression of the RAS components were evaluated by quantitative RT-PCR in renal tissue. After treatment, hyperglycemia and urine microalbumin levels were attenuated in both OL-DA and OL-VO rather than in the OL-C group (P renal RAS component expression, oxidative stress and interstitial fibrosis in OLETF rats. We suggest that, in addition to control of hyperglycemia, partial suppression of renal RAS with an SGLT2 inhibitor would be a promising strategy for the prevention of treatment of diabetic nephropathy.

  4. Long-term treatment with the sodium glucose cotransporter 2 inhibitor, dapagliflozin, ameliorates glucose homeostasis and diabetic nephropathy in db/db mice.

    Directory of Open Access Journals (Sweden)

    Naoto Terami

    Full Text Available Inhibition of sodium glucose cotransporter 2 (SGLT2 has been reported as a new therapeutic strategy for treating diabetes. However, the effect of SGLT2 inhibitors on the kidney is unknown. In addition, whether SGLT2 inhibitors have an anti-inflammatory or antioxidative stress effect is still unclear. In this study, to resolve these issues, we evaluated the effects of the SGLT2 inhibitor, dapagliflozin, using a mouse model of type 2 diabetes and cultured proximal tubular epithelial (mProx24 cells. Male db/db mice were administered 0.1 or 1.0 mg/kg of dapagliflozin for 12 weeks. Body weight, blood pressure, blood glucose, hemoglobin A1c, albuminuria and creatinine clearance were measured. Mesangial matrix accumulation and interstitial fibrosis in the kidney and pancreatic β-cell mass were evaluated by histological analysis. Furthermore, gene expression of inflammatory mediators, such as osteopontin, monocyte chemoattractant protein-1 and transforming growth factor-β, was evaluated by quantitative reverse transcriptase-PCR. In addition, oxidative stress was evaluated by dihydroethidium and NADPH oxidase 4 staining. Administration of 0.1 or 1.0 mg/kg of dapagliflozin ameliorated hyperglycemia, β-cell damage and albuminuria in db/db mice. Serum creatinine, creatinine clearance and blood pressure were not affected by administration of dapagliflozin, but glomerular mesangial expansion and interstitial fibrosis were suppressed in a dose-dependent manner. Dapagliflozin treatment markedly decreased macrophage infiltration and the gene expression of inflammation and oxidative stress in the kidney of db/db mice. Moreover, dapagliflozin suppressed the high-glucose-induced gene expression of inflammatory cytokines and oxidative stress in cultured mProx24 cells. These data suggest that dapagliflozin ameliorates diabetic nephropathy by improving hyperglycemia along with inhibiting inflammation and oxidative stress.

  5. Drug-drug interactions with sodium-glucose cotransporters type 2 (SGLT2) inhibitors, new oral glucose-lowering agents for the management of type 2 diabetes mellitus.

    Science.gov (United States)

    Scheen, André J

    2014-04-01

    Inhibitors of sodium-glucose cotransporters type 2 (SGLT2) reduce hyperglycaemia by decreasing renal glucose threshold and thereby increasing urinary glucose excretion. They are proposed as a novel approach for the management of type 2 diabetes mellitus. They have proven their efficacy in reducing glycated haemoglobin, without inducing hypoglycaemia, as monotherapy or in combination with various other glucose-lowering agents, with the add-on value of promoting some weight loss and lowering arterial blood pressure. As they may be used concomitantly with many other drugs, we review the potential drug-drug interactions (DDIs) regarding the three leaders in the class (dapagliglozin, canagliflozin and empagliflozin). Most of the available studies were performed in healthy volunteers and have assessed the pharmacokinetic interferences with a single administration of the SGLT2 inhibitor. The exposure [assessed by peak plasma concentrations (Cmax) and area under the concentration-time curve (AUC)] to each SGLT2 inhibitor tested was not significantly influenced by the concomitant administration of other glucose-lowering agents or cardiovascular agents commonly used in patients with type 2 diabetes. Reciprocally, these medications did not influence the pharmacokinetic parameters of dapagliflozin, canagliflozin or empagliflozin. Some modest changes were not considered as clinically relevant. However, drugs that could specifically interfere with the metabolic pathways of SGLT2 inhibitors [rifampicin, inhibitors or inducers of uridine diphosphate-glucuronosyltransferase (UGT)] may result in significant changes in the exposure of SGLT2 inhibitors, as shown for dapagliflozin and canagliflozin. Potential DDIs in patients with type 2 diabetes receiving chronic treatment with an SGLT2 inhibitor deserve further attention, especially in individuals treated with several medications or in more fragile patients with hepatic and/or renal impairment.

  6. Metabolic and hemodynamic effects of sodium-dependent glucose cotransporter 2 inhibitors on cardio-renal protection in the treatment of patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Kashiwagi, Atsunori; Maegawa, Hiroshi

    2017-07-01

    The specific sodium-glucose cotransporter 2 inhibitors (SGLT2 inhibitors) inhibit glucose reabsorption in proximal renal tubular cells, and both fasting and postprandial glucose significantly decrease because of urinary glucose loss. As a result, pancreatic β-cell function and peripheral insulin action significantly improve with relief from glucose toxicity. Furthermore, whole-body energy metabolism changes to relative glucose deficiency and triggers increased lipolysis in fat cells, and fatty acid oxidation and then ketone body production in the liver during treatment with SGLT2 inhibitors. In addition, SGLT2 inhibitors have profound hemodynamic effects including diuresis, dehydration, weight loss and lowering blood pressure. The most recent findings on SGLT2 inhibitors come from results of the Empagliflozin, Cardiovascular Outcomes and Mortality in Type 2 Diabetes trial. SGLT2 inhibitors exert extremely unique and cardio-renal protection through metabolic and hemodynamic effects, with long-term durability on the reduction of blood glucose, bodyweight and blood pressure. Although a site of action of SGLT2 inhibitors is highly specific to inhibit renal glucose reabsorption, whole-body energy metabolism, and hemodynamic and renal functions are profoundly modulated during the treatment of SGLT2 inhibitors. Previous studies suggest multifactorial clinical benefits and safety concerns of SGLT2 inhibitors. Although ambivalent clinical results of this drug are still under active discussion, the present review summarizes promising recent evidence on the cardio-renal and metabolic benefits of SGLT2 inhibitors in the treatment of type 2 diabetes. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  7. Safety of Sodium-Glucose Cotransporter 2 Inhibitors (SGLT2-I During the Month of Ramadan in Muslim Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Alaaeldin Bashier

    2018-03-01

    Full Text Available Objectives: Sodium-glucose cotransporter 2 inhibitors (SGLT2-I are a new class of antidiabetic drugs that might increase the risk of dehydration and hypoglycemia, particularly during the month of Ramadan in which Muslims abstain from eating and drinking for 14–16 hours daily. We aimed to provide real-life evidence about the safety of SGLT2-I during Ramadan. Methods: All patients over the age of 18 years on SGLT2-I before Ramadan 2016 who would be fasting during Ramadan were included. Demographic data, detailed medical history including comorbidities and medication profile, and laboratory results were collected before and after Ramadan. We also conducted a phone interview to evaluate the frequency and severity of hypoglycemia and dehydration. Results: Of the total of 417 patients, 113 (27.0% experienced hypoglycemic events, and 93 of these (82.3% checked their blood glucose using a glucometer. Confirmed hypoglycemia (< 70 mg/dL was observed in 78 (83.8%. The hypoglycemic events were significantly more frequent in the SGLT2-I plus insulin-treated group than in those treated with SGLT2-I plus oral hypoglycemic agents group (p < 0.001. Confirmed hypoglycemic events were more frequent in those using SGLT2-I plus intensive insulin compared to those using SGLT2-I plus basal insulin (p = 0.020. Symptoms of dehydration were seen in 9.3% (n = 39 of the total population. We observed statistically significant reductions in glycated hemoglobin and weight by the end of Ramadan (p < 0.001. There were no significant changes in lipid profile and creatinine levels by the end of the study. Conclusions: The use of insulin in combination with SGLT2-I increases the risk of hypoglycemia during Ramadan. Hypoglycemic events were mild and did not require hospital admission. However, careful monitoring during prolonged fasting is warranted. No significant harmful effects on renal function result from treatment with SGLT2-I during Ramadan.

  8. Sodium/bicarbonate cotransporter NBCn1/slc4a7 increases cytotoxicity in magnesium depletion in primary cultures of hippocampal neurons

    Science.gov (United States)

    Cooper, Deborah S.; Yang, Han Soo; He, Peijian; Kim, Eunjin; Rajbhandari, Ira; Yun, Chris C.; Choi, Inyeong

    2009-01-01

    Growing evidence suggests that pharmacological inhibition of Na/H exchange and Na/HCO3 transport provides protection against damage or injury in cardiac ischemia. In this study, we examined the contribution of the sodium/bicarbonate cotransporter NBCn1 (slc4a7) to cytotoxicity in cultured hippocampal neurons of rats. In neurons exposed to extracellular pH (pHo) ranging from 6.2 to 8.3, NBCn1 protein expression increased by fivefold at pH < 6.5 compared to the expression at pHo 7.4. At pHo 6.5, the intracellular pH of neurons was ~1 unit lower than that at pH 7.4. Immunochemistry showed a marked increase in NBCn1 immunofluorescence in plasma membranes and cytosol of the soma as well as in dendrites, at pHo 6.5. NBCn1 expression also increased by 40% in a prolonged Mg2+-free incubation at normal pHo. Knockdown of NBCn1 in neurons had negligible effect on cell viability. The effect of NBCn1 knockdown on cytotoxicity was then determined by exposing neurons to 0.5 mM glutamate for 10 min and measuring lactate dehydrogenase (LDH) release from neurons. Compared to normal incubation (pHo 7.2 for 6 h) after glutamate exposure, acidic incubation (pHo 6.3 for 6 h) reduced cytotoxicity by 75% for control neurons and 78% for NBCn1-knockdown neurons. Thus, both controls and knockdown neurons showed acidic protection from cytotoxicity. However, in Mg2+-free incubation after glutamate exposure, NBCn1 knockdown progressively attenuated cytotoxicity. This attenuation was unaffected by acidic preincubation before glutamate exposure. We conclude that NBCn1 has a dynamic upregulation in low pHo and Mg2+ depletion. NBCn1 is not required for acidic protection, but increases cytotoxicity in Mg2+-free conditions. PMID:19170751

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

    Science.gov (United States)

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

    2016-01-01

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

  10. Effects of diuretics on sodium-dependent glucose cotransporter 2 inhibitor-induced changes in blood pressure in obese rats suffering from the metabolic syndrome.

    Science.gov (United States)

    Rahman, Asadur; Kittikulsuth, Wararat; Fujisawa, Yoshihide; Sufiun, Abu; Rafiq, Kazi; Hitomi, Hirofumi; Nakano, Daisuke; Sohara, Eisei; Uchida, Shinichi; Nishiyama, Akira

    2016-05-01

    Experiments were carried out to investigate whether diuretics (hydrochlorothiazide + furosemide) impact on the effects of a sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor on glucose metabolism and blood pressure (BP) in metabolic syndrome SHR/NDmcr-cp(+/+) rats (SHRcp). Male 13-week-old SHRcp were treated with: vehicle; the SGLT2-inhibitor luseogliflozin (10 mg/kg per day); diuretics (hydrochlorothiazide; 10 mg/kg/day + furosemide; 5 mg/kg per day); or luseogliflozin + diuretics (n = 5-8 for each group) daily by oral gavage for 5 weeks. BP and glucose metabolism were evaluated by a telemetry system and oral glucose tolerance test, respectively. Vehicle-treated SHRcp developed nondipper type hypertension (dark vs. light-period mean arterial pressure: 148.6 ± 0.7 and 148.0 ± 0.7 mmHg, respectively, P = 0.2) and insulin resistance. Compared with vehicle-treated animals, luseogliflozin-treated rats showed an approximately 4000-fold increase in urinary excretion of glucose and improved glucose metabolism. Luseogliflozin also significantly decreased BP and turned the circadian rhythm of BP from a nondipper to dipper pattern (dark vs. light-period mean arterial pressure: 138.0 ± 1.6 and 132.0 ± 1.3 mmHg, respectively, P diuretics did not influence luseogliflozin-induced improvement of glucose metabolism and circadian rhythm of BP in SHRcp. These data suggest that a SGLT2 inhibitor elicits its beneficial effects on glucose metabolism and hypertension in study participants with metabolic syndrome undergoing treatment with diuretics.

  11. K-Cl Cotransporter 2–mediated Cl− Extrusion Determines Developmental Stage–dependent Impact of Propofol Anesthesia on Dendritic Spines

    KAUST Repository

    Puskarjov, Martin; Fiumelli, Hubert; Briner, Adrian; Bodogan, Timea; Demeter, Kornel; Lacoh, Claudia Marvine; Mavrovic, Martina; Blaesse, Peter; Kaila, Kai; Vutskits, Laszlo

    2017-01-01

    Background: General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABA A)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). Methods: In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABA A)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. Results: The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl - transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. Conclusions: The KCC2-dependent developmental increase in the efficacy of GABA A -mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

  12. Functional expression of the Na-K-2Cl cotransporter NKCC2 in mammalian cells fails to confirm the dominant-negative effect of the AF splice variant.

    Science.gov (United States)

    Hannemann, Anke; Christie, Jenny K; Flatman, Peter W

    2009-12-18

    The renal bumetanide-sensitive Na-K-2Cl cotransporter (NKCC2) is the major salt transport pathway in the apical membrane of the mammalian thick ascending limb. It is differentially spliced and the three major variants (A, B, and F) differ in their localization and transport characteristics. Most knowledge about its regulation comes from experiments in Xenopus oocytes as NKCC2 proved difficult to functionally express in a mammalian system. Here we report the cloning and functional expression of untagged and unmodified versions of the major splice variants from ferret kidney (fNKCC2A, -B, and -F) in human embryonic kidney (HEK) 293 cells. Many NKCC2 antibodies used in this study detected high molecular weight forms of the transfected proteins, probably NKCC2 dimers, but not the monomers. Interestingly, monomers were strongly detected by phosphospecific antibodies directed against phosphopeptides in the regulatory N terminus. Bumetanide-sensitive (86)Rb uptake was significantly higher in transfected HEK-293 cells and could be stimulated by incubating cells in a medium containing a low chloride concentration prior the uptake measurements. fNKCC2 was less sensitive to the reduction in chloride concentration than NKCC1. Using HEK-293 cells stably expressing fNKCC2A we also show that co-expression of variant NKCC2AF does not have the dominant-negative effect on NKCC2A activity that was seen in Xenopus oocytes, nor is it trafficked to the cell surface. In addition, fNKCC2AF is neither complex glycosylated nor phosphorylated in its N terminus regulatory region like other variants.

  13. Reactive neurogenesis and down-regulation of the potassium-chloride cotransporter KCC2 in the cochlear nuclei after cochlear deafferentation

    Directory of Open Access Journals (Sweden)

    Brahim Tighilet

    2016-08-01

    Full Text Available While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus of cats. We found a strong cell proliferation in all the cochlear nucleus sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to one month after cochlear deafferentation in all cochlear nuclei (except the dorsal cochlear nucleus and give rise to a variety of cell types, i.e. microglial cells, astrocytes and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and downregulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis.

  14. Oral peptide specific egg antibody to intestinal sodium-dependent phosphate co-transporter-2b is effective at altering phosphate transport in vitro and in vivo.

    Science.gov (United States)

    Bobeck, Elizabeth A; Hellestad, Erica M; Sand, Jordan M; Piccione, Michelle L; Bishop, Jeff W; Helvig, Christian; Petkovich, Martin; Cook, Mark E

    2015-06-01

    Hyperimmunized hens are an effective means of generating large quantities of antigen specific egg antibodies that have use as oral supplements. In this study, we attempted to create a peptide specific antibody that produced outcomes similar to those of the human pharmaceutical, sevelamer HCl, used in the treatment of hyperphosphatemia (a sequela of chronic renal disease). Egg antibodies were generated against 8 different human intestinal sodium-dependent phosphate cotransporter 2b (NaPi2b) peptides, and hNaPi2b peptide egg antibodies were screened for their ability to inhibit phosphate transport in human intestinal Caco-2 cell line. Antibody produced against human peptide sequence TSPSLCWT (anti-h16) was specific for its peptide sequence, and significantly reduced phosphate transport in human Caco-2 cells to 25.3±11.5% of control nonspecific antibody, when compared to nicotinamide, a known inhibitor of phosphate transport (P≤0.05). Antibody was then produced against the mouse-specific peptide h16 counterpart (mouse sequence TSPSYCWT, anti-m16) for further analysis in a murine model. When anti-m16 was fed to mice (1% of diet as dried egg yolk powder), egg yolk immunoglobulin (IgY) was detected using immunohistochemical staining in mouse ileum, and egg anti-m16 IgY colocalized with a commercial goat anti-NaPi2b antibody. The effectiveness of anti-m16 egg antibody in reducing serum phosphate, when compared to sevelamer HCl, was determined in a mouse feeding study. Serum phosphate was reduced 18% (Pegg yolk powder) and 30% (Pegg immunoglobulin. The methods described and the findings reported show that oral egg antibodies are useful and easy to prepare reagents for the study and possible treatment of select diseases. © 2015 Poultry Science Association Inc.

  15. Mutation of the Na(+)-K(+)-2Cl(-) cotransporter NKCC2 in mice is associated with severe polyuria and a urea-selective concentrating defect without hyperreninemia.

    Science.gov (United States)

    Kemter, Elisabeth; Rathkolb, Birgit; Bankir, Lise; Schrewe, Anja; Hans, Wolfgang; Landbrecht, Christina; Klaften, Matthias; Ivandic, Boris; Fuchs, Helmut; Gailus-Durner, Valérie; Hrabé de Angelis, Martin; Wolf, Eckhard; Wanke, Ruediger; Aigner, Bernhard

    2010-06-01

    The bumetanide-sensitive Na(+)-K(+)-2Cl(-) cotransporter NKCC2, located in the thick ascending limb of Henle's loop, plays a critical role in the kidney's ability to concentrate urine. In humans, loss-of-function mutations of the solute carrier family 12 member 1 gene (SLC12A1), coding for NKCC2, cause type I Bartter syndrome, which is characterized by prenatal onset of a severe polyuria, salt-wasting tubulopathy, and hyperreninemia. In this study, we describe a novel chemically induced, recessive mutant mouse line termed Slc12a1(I299F) exhibiting late-onset manifestation of type I Bartter syndrome. Homozygous mutant mice are viable and exhibit severe polyuria, metabolic alkalosis, marked increase in plasma urea but close to normal creatininemia, hypermagnesemia, hyperprostaglandinuria, hypotension,, and osteopenia. Fractional excretion of urea is markedly decreased. In addition, calcium and magnesium excretions are more than doubled compared with wild-type mice, while uric acid excretion is twofold lower. In contrast to hyperreninemia present in human disease, plasma renin concentration in homozygotes is not increased. The polyuria observed in homozygotes may be due to the combination of two additive factors, a decrease in activity of mutant NKCC2 and an increase in medullary blood flow, due to prostaglandin-induced vasodilation, that impairs countercurrent exchange of urea in the medulla. In conclusion, this novel viable mouse line with a missense Slc12a1 mutation exhibits most of the features of type I Bartter syndrome and may represent a new model for the study of this human disease.

  16. Expression of Na+/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners.

    Science.gov (United States)

    Moran, Andrew W; Al-Rammahi, Miran A; Arora, Daleep K; Batchelor, Daniel J; Coulter, Erin A; Daly, Kristian; Ionescu, Catherine; Bravo, David; Shirazi-Beechey, Soraya P

    2010-09-01

    In an intensive livestock production, a shorter suckling period allows more piglets to be born. However, this practice leads to a number of disorders including nutrient malabsorption, resulting in diarrhoea, malnutrition and dehydration. A number of strategies have been proposed to overcome weaning problems. Artificial sweeteners, routinely included in piglets' diet, were thought to enhance feed palatability. However, it is shown in rodent models that when included in the diet, they enhance the expression of Na+/glucose co-transporter (SGLT1) and the capacity of the gut to absorb glucose. Here, we show that supplementation of piglets' feed with a combination of artificial sweeteners saccharin and neohesperidin dihydrochalcone enhances the expression of SGLT1 and intestinal glucose transport function. Artificial sweeteners are known to act on the intestinal sweet taste receptor T1R2/T1R3 and its partner G-protein, gustducin, to activate pathways leading to SGLT1 up-regulation. Here, we demonstrate that T1R2, T1R3 and gustducin are expressed together in the enteroendocrine cells of piglet intestine. Furthermore, gut hormones secreted by the endocrine cells in response to dietary carbohydrates, glucagon-like peptides (GLP)-1, GLP-2 and glucose-dependent insulinotrophic peptide (GIP), are co-expressed with type 1 G-protein-coupled receptors (T1R) and gustducin, indicating that L- and K-enteroendocrine cells express these taste elements. In a fewer endocrine cells, T1R are also co-expressed with serotonin. Lactisole, an inhibitor of human T1R3, had no inhibitory effect on sweetener-induced SGLT1 up-regulation in piglet intestine. A better understanding of the mechanism(s) involved in sweetener up-regulation of SGLT1 will allow the identification of nutritional targets with implications for the prevention of weaning-related malabsorption.

  17. Regulation of the Na(+)-K(+)-2Cl(-) cotransporter by cGMP/cGMP-dependent protein kinase I after furosemide administration.

    Science.gov (United States)

    Limmer, Franziska; Schinner, Elisabeth; Castrop, Hayo; Vitzthum, Helga; Hofmann, Franz; Schlossmann, Jens

    2015-10-01

    Sodium chloride reabsorption in the thick ascending limb of the loop of Henle is mediated by the Na(+)-K(+)-2Cl(-) cotransporter (NKCC2). The loop diuretic furosemide is a potent inhibitor of NKCC2. However, less is known about the mechanism regulating the electrolyte transporter. Considering the well-established effects of nitric oxide on NKCC2 activity, cGMP is likely involved in this regulation. cGMP-dependent protein kinase I (cGKI; PKGI) is a cGMP target protein that phosphorylates different substrates after activation through cGMP. We investigated the potential correlation between the cGMP/cGKI pathway and NKCC2 regulation. We treated wild-type (wt) and cGKIα-rescue mice with furosemide. cGKIα-rescue mice expressed cGKIα only under the control of the smooth muscle-specific transgelin (SM22) promoter in a cGKI deficient background. Furosemide treatment increased the urine excretion of sodium and chloride in cGKIα-rescue mice compared to that in wt mice. We analyzed the phosphorylation of NKCC2 by western blotting and immunostaining using the phosphospecific antibody R5. The administration of furosemide significantly increased the phosphorylated NKCC2 signal in wt but not in cGKIα-rescue mice. NKCC2 activation led to its phosphorylation and membrane translocation. To examine whether cGKI was involved in this process, we analyzed vasodilator-stimulated phosphoprotein, which is phosphorylated by cGKI. Furosemide injection resulted in increased vasodilator-stimulated phosphoprotein phosphorylation in wt mice. We hypothesize that furosemide administration activated cGKI, leading to NKCC2 phosphorylation and membrane translocation. This cGKI-mediated pathway could be a mechanism to compensate for the inhibitory effect of furosemide on NKCC2. © 2015 FEBS.

  18. The role of aspartic acid residues 405 and 416 of the kidney isotype of sodium-bicarbonate cotransporter 1 in its targeting to the plasma membrane

    Science.gov (United States)

    Kucher, Volodymyr; Li, Emily Y.; Conforti, Laura; Zahedi, Kamyar A.

    2012-01-01

    The NH2 terminus of the sodium-bicarbonate cotransporter 1 (NBCe1) plays an important role in its targeting to the plasma membrane. To identify the amino acid residues that contribute to the targeting of NBCe1 to the plasma membrane, polarized MDCK cells were transfected with expression constructs coding for green fluorescent protein (GFP)-tagged NBCe1 NH2-terminal deletion mutants, and the localization of GFP-tagged proteins was analyzed by confocal microscopy. Our results indicate that the amino acids between residues 399 and 424 of NBCe1A contain important sequences that contribute to its localization to the plasma membrane. Site-directed mutagenesis studies showed that GFP-NBCe1A mutants D405A and D416A are retained in the cytoplasm of the polarized MDCK epithelial cells. Examination of functional activities of D405A and D416A reveals that their activities are reduced compared with the wild-type NBCe1A. Similarly, aspartic acid residues 449 and 460 of pancreatic NBCe1 (NBCe1B), which correspond to residues 405 and 416 of NBCe1A, are also required for its full functional activity and accurate targeting to the plasma membrane. In addition, while replacement of D416 with glutamic acid did not affect the targeting or functional activity of NBCe1A, substitution of D405 with glutamic acid led to the retention of the mutated protein in the intracellular compartment and impaired functional activity. These studies demonstrate that aspartic acid residues 405 and 416 in the NH2 terminus of NBCe1A are important in its accurate targeting to the plasma membrane. PMID:22442137

  19. Diabetes and kidney disease: the role of sodium-glucose cotransporter-2 (SGLT-2) and SGLT-2 inhibitors in modifying disease outcomes.

    Science.gov (United States)

    Mende, Christian W

    2017-03-01

    Patients with type 2 diabetes (T2D) often have coexisting chronic kidney disease (CKD). However, healthy renal function is crucial in maintaining glucose homeostasis, assuring that almost all of the filtered glucose is reabsorbed by the sodium glucose cotransporters (SGLTs) SGLT-1 and SGLT-2. In diabetes, an increased amount of glucose is filtered by the kidneys and SGLT-2 is upregulated, leading to increased glucose absorption and worsening hyperglycemia. Prolonged hyperglycemia contributes to the development of CKD by inducing metabolic and hemodynamic changes in the kidneys. Due to the importance of SGLT-2 in regulating glucose levels, investigation into SGLT-2 inhibitors was initiated as a glucose-dependent mechanism to control hyperglycemia, and there are three agents currently approved for use in the United States: dapagliflozin, canagliflozin, and empagliflozin. SGLT-2 inhibitors have been shown to reduce glycated hemoglobin (A1C), weight, and blood pressure, which not only affects glycemic control, but may also help slow the progression of renal disease by impacting the underlying mechanisms of kidney injury. In addition, SGLT-2 inhibitors have shown reductions in albuminuria, uric acid, and an increase in magnesium. Caution is advised when prescribing SGLT-2 inhibitors to patients with moderately impaired renal function and those at risk for volume depletion and hypotension. Published data on slowing of the development, as well as progression of CKD, is a hopeful indicator for the possible renal protection potential of this drug class. This narrative review provides an in-depth discussion of the interplay between diabetes, SGLT-2 inhibitors, and factors that affect kidney function.

  20. LX4211 increases serum glucagon-like peptide 1 and peptide YY levels by reducing sodium/glucose cotransporter 1 (SGLT1)-mediated absorption of intestinal glucose.

    Science.gov (United States)

    Powell, David R; Smith, Melinda; Greer, Jennifer; Harris, Angela; Zhao, Sharon; DaCosta, Christopher; Mseeh, Faika; Shadoan, Melanie K; Sands, Arthur; Zambrowicz, Brian; Ding, Zhi-Ming

    2013-05-01

    LX4211 [(2S,3R,4R,5S,6R)-2-(4-chloro-3-(4-ethoxybenzyl)phenyl)-6-(methylthio)tetrahydro-2H-pyran-3,4,5-triol], a dual sodium/glucose cotransporter 1 (SGLT1) and SGLT2 inhibitor, is thought to decrease both renal glucose reabsorption by inhibiting SGLT2 and intestinal glucose absorption by inhibiting SGLT1. In clinical trials in patients with type 2 diabetes mellitus (T2DM), LX4211 treatment improved glycemic control while increasing circulating levels of glucagon-like peptide 1 (GLP-1) and peptide YY (PYY). To better understand how LX4211 increases GLP-1 and PYY levels, we challenged SGLT1 knockout (-/-) mice, SGLT2-/- mice, and LX4211-treated mice with oral glucose. LX4211-treated mice and SGLT1-/- mice had increased levels of plasma GLP-1, plasma PYY, and intestinal glucose during the 6 hours after a glucose-containing meal, as reflected by area under the curve (AUC) values, whereas SGLT2-/- mice showed no response. LX4211-treated mice and SGLT1-/- mice also had increased GLP-1 AUC values, decreased glucose-dependent insulinotropic polypeptide (GIP) AUC values, and decreased blood glucose excursions during the 6 hours after a challenge with oral glucose alone. However, GLP-1 and GIP levels were not increased in LX4211-treated mice and were decreased in SGLT1-/- mice, 5 minutes after oral glucose, consistent with studies linking decreased intestinal SGLT1 activity with reduced GLP-1 and GIP levels 5 minutes after oral glucose. These data suggest that LX4211 reduces intestinal glucose absorption by inhibiting SGLT1, resulting in net increases in GLP-1 and PYY release and decreases in GIP release and blood glucose excursions. The ability to inhibit both intestinal SGLT1 and renal SGLT2 provides LX4211 with a novel dual mechanism of action for improving glycemic control in patients with T2DM.

  1. K-Cl Cotransporter 2–mediated Cl− Extrusion Determines Developmental Stage–dependent Impact of Propofol Anesthesia on Dendritic Spines

    KAUST Repository

    Puskarjov, Martin

    2017-03-16

    Background: General anesthetics potentiating γ-aminobutyric acid (GABA)-mediated signaling are known to induce a persistent decrement in excitatory synapse number in the cerebral cortex when applied during early postnatal development, while an opposite action is produced at later stages. Here, the authors test the hypothesis that the effect of general anesthetics on synaptogenesis depends upon the efficacy of GABA receptor type A (GABA A)-mediated inhibition controlled by the developmental up-regulation of the potassium-chloride (K-Cl) cotransporter 2 (KCC2). Methods: In utero electroporation of KCC2 was used to prematurely increase the efficacy of (GABA A)-mediated inhibition in layer 2/3 pyramidal neurons in the immature rat somatosensory cortex. Parallel experiments with expression of the inward-rectifier potassium channel Kir2.1 were done to reduce intrinsic neuronal excitability. The effects of these genetic manipulations (n = 3 to 4 animals per experimental group) were evaluated using iontophoretic injection of Lucifer Yellow (n = 8 to 12 cells per animal). The total number of spines analyzed per group ranged between 907 and 3,371. Results: The authors found a robust effect of the developmental up-regulation of KCC2-mediated Cl - transport on the age-dependent action of propofol on dendritic spines. Premature expression of KCC2, unlike expression of a transport-inactive KCC2 variant, prevented a propofol-induced decrease in spine density. In line with a reduction in neuronal excitability, the above result was qualitatively replicated by overexpression of Kir2.1. Conclusions: The KCC2-dependent developmental increase in the efficacy of GABA A -mediated inhibition is a major determinant of the age-dependent actions of propofol on dendritic spinogenesis.

  2. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman's capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium.

    Science.gov (United States)

    Tabatabai, Niloofar M; North, Paula E; Regner, Kevin R; Kumar, Suresh N; Duris, Christine B; Blodgett, Amy B

    2014-08-01

    In kidney nephron, parietal epithelial cells line the Bowman's capsule and function as a permeability barrier for the glomerular filtrate. Bowman's capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman's capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane (BBM) of epithelial cells in the early segment of the proximal tubule. We hypothesized that SGLT2 is expressed in tubularized Bowman's capsule and used our novel antibody to test this hypothesis. Immunohistochemical analysis was performed with our SGLT2 antibody on C57BL/6 mouse kidney prone to have tubularized Bowman's capsules. Cell membrane was examined with periodic acid-Schiff (PAS) stain. The results showed that SGLT2 was localized on BBM of the proximal tubules in young and adult mice. Bowman's capsules were lined mostly with normal brush border-less parietal epithelial cells in young mice, while they were almost completely covered with proximal tubule-like cells in adult mice. Regardless of age, SGLT2 was expressed on BBM of the tubularized Bowman's capsule but did not co-localize with nephrin in the glomerulus. SGLT2-expressing tubular cells expanded from the urinary pole toward the vascular pole of the Bowman's capsule. This study identified the localization of SGLT2 in the Bowman's capsule. Bowman's capsules with tubular metaplasia may acquire roles in reabsorption of filtered glucose and sodium.

  3. Vectorial transport of bile salts across MDCK cells expressing both rat Na+-taurocholate cotransporting polypeptide and rat bile salt export pump.

    Science.gov (United States)

    Mita, Sachiko; Suzuki, Hiroshi; Akita, Hidetaka; Stieger, Bruno; Meier, Peter J; Hofmann, Alan F; Sugiyama, Yuichi

    2005-01-01

    Bile salts are predominantly taken up by hepatocytes via the basolateral Na(+)-taurocholate cotransporting polypeptide (NTCP/SLC10A1) and secreted into the bile by the bile salt export pump (BSEP/ABCB11). In the present study, we transfected rat Ntcp and rat Bsep into polarized Madin-Darby canine kidney cells and characterized the transport properties of these cells for eight bile salts. Immunohistochemical staining demonstrated that Ntcp was expressed at the basolateral domains, whereas Bsep was expressed at the apical domains. Basal-to-apical transport of taurocholate across the monolayer expressing only Ntcp and that coexpressing Ntcp/Bsep was observed, whereas the flux across the monolayer of control and Bsep-expressing cells was symmetrical. Basal-to-apical transport of taurocholate across Ntcp/Bsep-coexpressing monolayers was significantly higher than that across monolayers expressing only Ntcp. Kinetic analysis of this vectorial transport of taurocholate gave an apparent K(m) value of 13.9 +/- 4.7 microM for cells expressing Ntcp alone, which is comparable with 22.2 +/- 4.5 microM for cells expressing both Ntcp and Bsep and V(max) values of 15.8 +/- 4.2 and 60.8 +/- 9.0 pmol.min(-1).mg protein(-1) for Ntcp alone and Ntcp and Bsep-coexpressing cells, respectively. Transcellular transport of cholate, glycocholate, taurochenodeoxycholate, chenodeoxycholate, glycochenodeoxycholate, tauroursodeoxycholate, ursodeoxycholate, and glycoursodeoxycholate, but not that of lithocholate was also observed across the double transfectant. This double-expressing system can be used as a model to clarify vectorial transport of bile salts across hepatocytes under physiological conditions.

  4. Hydrogen sulfide upregulated mRNA expressions of sodium bicarbonate cotransporter1, trefoil factor1 and trefoil factor2 in gastric mucosa in rats.

    Science.gov (United States)

    Cheraghi, Parisa; Mard, Seyyed Ali; Nagi, Tahereh

    2016-01-01

    Hydrogen sulfide (H 2 S) has been shown to protect the gastric mucosa through several protective mechanisms but till now its effect on mRNA expression of sodium bicarbonate cotransporter 1 (NBC1), trefoil factor1 (TFF1) and trefoil factor2 (TFF2) was not investigated. This study was aimed to evaluate the effect of H 2 S on mRNA expression of NBC1, TFF1 and TFF2 in rat gastric mucosa in response to gastric distention. Thirty two rats were randomly assigned into four equal groups. They were control (C), distention (D), propargylglycine (PAG)-, and NaHS-treated groups. To evaluate the effect of exogenous and endogenous H 2 S on gene expression of NBC1, TFF1 and TFF2, two groups of rats were received H 2 S donor, intra-peritoneal NaHS (80 µg Kg -1 ), and PAG (50 mg kg -1 ), accompanied to stimulate the gastric acid secretion, respectively. Under general anesthesia and laparotomy, a catheter was inserted into the stomach through duodenum for instillation of isotonic saline for gastric distention. Ninety min after beginning the experiment, animals were sacrificed and the gastric mucosa was collected to determine total acid content of gastric effluents and to quantify the mRNA expression of studied genes by quantitative real-time polymerase chain reaction (qRT-PCR). Results showed that A) gastric distention increased the level of mRNA expressions of NBC1, TFF1 and TFF2; B) these levels in NaHS-treated rats were significantly higher than those in Distention group; and C) PAG decreased the expression levels of NBC1 and TFF1. The Findings showed H 2 S upregulated gene expression of NBC1, TFF1 and TFF2 in gastric mucosa.

  5. A sea urchin Na(+)K(+)2Cl(-) cotransporter is involved in the maintenance of calcification-relevant cytoplasmic cords in Strongylocentrotus droebachiensis larvae.

    Science.gov (United States)

    Basse, Wiebke C; Gutowska, Magdalena A; Findeisen, Ulrike; Stumpp, Meike; Dupont, Sam; Jackson, Daniel J; Himmerkus, Nina; Melzner, Frank; Bleich, Markus

    2015-09-01

    The cellular mechanisms of calcification in sea urchin larvae are still not well understood. Primary mesenchyme cells within the larval body cavity form a syncytium to secrete CaCO3 spicules from intracellular amorphous CaCO3 (ACC) stores. We studied the role of Na(+)K(+)2Cl(-) cotransporter (NKCC) in intracellular ACC accumulation and larval spicule formation of Strongylocentrotus droebachiensis. First, we incubated growing larvae with three different loop diuretics (azosemide, bumetanide, and furosemide) and established concentration-response curves. All loop diuretics were able to inhibit calcification already at concentrations that specifically inhibit NKCC. Calcification was most effectively inhibited by azosemide (IC50=6.5 μM), while larval mortality and swimming ability were not negatively impacted by the treatment. The inhibition by bumetanide (IC50=26.4 μM) and furosemide (IC50=315.4 μM) resembled the pharmacological fingerprint of the mammalian NKCC1 isoform. We further examined the effect of azosemide on the maintenance of cytoplasmic cords and on the occurrence of calcification vesicles using fluorescent dyes (calcein, FM1-43). Fifty micromolars of azosemide inhibited the maintenance of cytoplasmic cords and resulted in increased calcein fluorescence within calcification vesicles. The expression of NKCC in S. droebachiensis was verified by PCR and Western blot with a specific NKCC antibody. In summary, the pharmacological profile of loop diuretics and their specific effects on calcification in sea urchin larvae suggest that they act by inhibition of NKCC via repression of cytoplasmic cord formation and maintenance. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Intronic deletions in the SLC34A3 gene: A cautionary tale for mutation analysis of hereditary hypophosphatemic rickets with hypercalciuria

    OpenAIRE

    Ichikawa, Shoji; Tuchman, Shamir; Padgett, Leah R.; Gray, Amie K.; Baluarte, H. Jorge; Econs, Michael J.

    2013-01-01

    Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare metabolic disorder, characterized by hypophosphatemia, variable degrees of rickets/osteomalacia, and hypercalciuria secondary to increased serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels. HHRH is caused by mutations in the SLC34A3 gene, which encodes sodium-phosphate co-transporter type IIc. A 6 ½-year-old female presented with a history of nephrolithiasis. Her metabolic evaluation revealed increased 24- hour urine cal...

  7. Sodium glucose co-transporter inhibitors for the management of diabetes mellitus: an opinion paper from the Endocrine and Metabolism Practice and Research Network of the American College of Clinical Pharmacy.

    Science.gov (United States)

    Clements, Jennifer N; Whitley, Heather P; D'Souza, Jennifer J; Gross, Benjamin; Hess, Rick; Reece, Sara; Gentry, Chad; Shealy, Kayce

    2015-01-01

    Type 2 diabetes mellitus (T2DM) carries a high prevalence in the United States and worldwide. Therefore, the number of medication classes being developed and studied has grown. The individualized management of diabetes is accomplished by evaluating a medication's efficacy, safety, and cost, along with the patient's preference and tolerance to the medication. Sodium glucose co-transporter 2 inhibitors are a new therapeutic class indicated for the treatment of diabetes and have a unique mechanism of action, independent of beta-cell function. The first agent approved by the Food and Drug Administration (FDA) was canagliflozin in March 2013. Two agents - dapagliflozin and empagliflozin - were FDA-approved in January and July 2014, respectively. A clear understanding of the new class is needed to identify its appropriate use in clinical practice. Members of the American College of Clinical Pharmacy Endocrine and Metabolism Practice and Research Network reviewed available literature regarding this therapeutic class. The article addresses the advantages, disadvantages, emerging role, and patient education for sodium glucose co-transporter 2 inhibitors. Key limitations for this article include limited access to clinical trial data not published by the pharmaceutical company and limited data on products produced outside the United States.

  8. Cotransporting Ion is a Trigger for Cellular Endocytosis of Transporter-Targeting Nanoparticles: A Case Study of High-Efficiency SLC22A5 (OCTN2)-Mediated Carnitine-Conjugated Nanoparticles for Oral Delivery of Therapeutic Drugs.

    Science.gov (United States)

    Kou, Longfa; Yao, Qing; Sun, Mengchi; Wu, Chunnuan; Wang, Jia; Luo, Qiuhua; Wang, Gang; Du, Yuqian; Fu, Qiang; Wang, Jian; He, Zhonggui; Ganapathy, Vadivel; Sun, Jin

    2017-09-01

    OCTN2 (SLC22A5) is a Na + -coupled absorption transporter for l-carnitine in small intestine. This study tests the potential of this transporter for oral delivery of therapeutic drugs encapsulated in l-carnitine-conjugated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (LC-PLGA NPs) and discloses the molecular mechanism for cellular endocytosis of transporter-targeting nanoparticles. Conjugation of l-carnitine to a surface of PLGA-NPs enhances the cellular uptake and intestinal absorption of encapsulated drug. In both cases, the uptake process is dependent on cotransporting ion Na + . Computational OCTN2 docking analysis shows that the presence of Na + is important for the formation of the energetically stable intermediate complex of transporter-Na + -LC-PLGA NPs, which is also the first step in cellular endocytosis of nanoparticles. The transporter-mediated intestinal absorption of LC-PLGA NPs occurs via endocytosis/transcytosis rather than via the traditional transmembrane transport. The portal blood versus the lymphatic route is evaluated by the plasma appearance of the drug in the control and lymph duct-ligated rats. Absorption via the lymphatic system is the predominant route in the oral delivery of the NPs. In summary, LC-PLGA NPs can effectively target OCTN2 on the enterocytes for enhancing oral delivery of drugs and the critical role of cotransporting ions should be noticed in designing transporter-targeting nanoparticles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Oncogenic p95HER2 regulates Na+-HCO3- cotransporter NBCn1 mRNA stability in breast cancer cells via 3'UTR-dependent processes.

    Science.gov (United States)

    Gorbatenko, Andrej; Olesen, Christina W; Loebl, Nathalie; Sigurdsson, Haraldur H; Bianchi, Carolina; Pedraz-Cuesta, Elena; Christiansen, Jan; Pedersen, Stine Falsig

    2016-11-01

    The Na + -HCO 3 - cotransporter NBCn1 (SLC4A7) is up-regulated in breast cancer, important for tumor growth, and a single nucleotide polymorphism (SNP), rs4973768, in its 3' untranslated region (3'UTR) correlates with increased breast cancer risk. We previously demonstrated that NBCn1 expression and promoter activity are strongly increased in breast cancer cells expressing a constitutively active oncogenic human epidermal growth factor receptor 2 (HER2) (p95HER2). Here, we address the roles of p95HER2 in regulating NBCn1 expression via post-transcriptional mechanisms. p95HER2 expression in MCF-7 cells reduced the rate of NBCn1 mRNA degradation. The NBCn1 3'UTR down-regulated luciferase reporter expression in control cells, and this was reversed by p95HER2, suggesting that p95HER2 counteracts 3'UTR-mediated suppression of NBCn1 expression. Truncation analyses identified three NBCn1 3'UTR regions of regulatory importance. Mutation of putative miRNA-binding sites (miR-374a/b, miR-200b/c, miR-29a/b/c, miR-488) in these regions did not have significant impact on 3'UTR activity. The NBCn1 3'UTR interacted directly with the RNA-binding protein human antigen R (HuR), and HuR knockdown reduced NBCn1 expression. Conversely, ablation of a distal AU-rich element increased 3'UTR-driven reporter activity, suggesting complex regulatory roles of these sites. The cancer-associated SNP variant decreased reporter expression in T-47D breast cancer cells, yet not in MCF-7, MDA-MB-231 and SK-BR-3 cells, arguing against a general role in regulating NBCn1 expression. Finally, p95HER2 expression increased total and plasma membrane NBCn1 protein levels and decreased the rate of NBCn1 protein degradation. Collectively, this is the first work to demonstrate 3'UTR-mediated NBCn1 regulation, shows that p95HER2 regulates NBCn1 expression at multiple levels, and substantiates the central position of p95HER2-NBCn1 signaling in breast cancer. © 2016 The Author(s); published by Portland Press

  10. Sodium–glucose cotransporter-2 inhibition and acidosis in patients with type 2 diabetes: a review of US FDA data and possible conclusions

    Directory of Open Access Journals (Sweden)

    D'Elia JA

    2017-06-01

    Full Text Available John A D’Elia,1 Alissa R Segal,1,2 George P Bayliss,3 Larry A Weinrauch1 1Kidney and Hypertension Section, Joslin Diabetes Center, Harvard Medical School, 2Department of Pharmacy Practice, MCPHS University, Boston, MA, 3Division of Kidney Diseases and Hypertension, Rhode Island Hospital, Alpert Medical School, Brown University, Providence, RI, USA Objective: To evaluate whether adverse event reports to the US Food and Drug Administration on incidents of ketoacidosis from use of sodium glucose cotransport inhibitors (SGLT2 inhibitors provide insight into ways this new class of drugs is being prescribed with other antihyperglycemic agents; to examine possible mechanisms to explain ketoacidosis.Design and methods: Reports of adverse events concerned to SGLT2 inhibitors, namely, empagliflozin, dapagliflozin, and canagliflozin were obtained under the Freedom of Information Act for 5 years ending in August 31, 2015. The data were evaluated for incidents of ketoacidosis by looking for keywords such as diabetic ketoacidosis, ketoacidosis, lactic acidosis, acidosis, and metabolic acidosis. Results were tabulated individually for empagliflozin (n=260 adverse event reports, dapagliflozin (n=520, and canagliflozin (n=2159. Adverse events were categorized according to age, gender, and insulin use.Results: There were 46, 144, and 450 reports of ketoacidosis concerned with the use of empagliflozin, dapagliflozin, and canagliflozin, respectively. The use of SGLT2 inhibitors was not strictly limited to patients with type 2 diabetes but was cut across categories of insulin use, including a total of 172 cases of SGLT2-related ketoacidosis in individuals above the age of 40 who were not on insulin.Conclusion: Further studies should focus to detect pleiotropic effects of SGLT2 inhibitors, particularly with other oral antihyperglycemic drugs or insulin. A review of the literature suggests that patients with type 2 diabetes with low C-peptide level may be at

  11. Benefits and Harms of Sodium-Glucose Co-Transporter 2 Inhibitors in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Gluud, Lise L.; Bennett, Cathy; Grøndahl, Magnus F.; Christensen, Mikkel B.; Knop, Filip K.; Vilsbøll, Tina

    2016-01-01

    Objective Sodium-glucose co-transporter 2 inhibitors (SGLT2-i) are a novel drug class for the treatment of diabetes. We aimed at describing the maximal benefits and risks associated with SGLT2-i for patients with type 2 diabetes. Design Systematic review and meta-analysis. Data Sources and Study Selection We included double-blinded, randomised controlled trials (RCTs) evaluating SGLT2-i administered in the highest approved therapeutic doses (canagliflozin 300 mg/day, dapagliflozin 10 mg/day, and empagliflozin 25 mg/day) for ≥12 weeks. Comparison groups could receive placebo or oral antidiabetic drugs (OAD) including metformin, sulphonylureas (SU), or dipeptidyl peptidase 4 inhibitors (DPP-4-i). Trials were identified through electronic databases and extensive manual searches. Primary outcomes were glycated haemoglobin A1c (HbA1c) levels, serious adverse events, death, severe hypoglycaemia, ketoacidosis and CVD. Secondary outcomes were fasting plasma glucose, body weight, blood pressure, heart rate, lipids, liver function tests, creatinine and adverse events including infections. The quality of the evidence was assessed using GRADE. Results Meta-analysis of 34 RCTs with 9,154 patients showed that SGLT2-i reduced HbA1c compared with placebo (mean difference -0.69%, 95% confidence interval -0.75 to -0.62%). We downgraded the evidence to ‘low quality’ due to variability and evidence of publication bias (P = 0.015). Canagliflozin was associated with the largest reduction in HbA1c (-0.85%, -0.99% to -0.71%). There were no differences between SGLT2-i and placebo for serious adverse events. SGLT2-i increased the risk of urinary and genital tract infections and increased serum creatinine, and exerted beneficial effects on bodyweight, blood pressure, lipids and alanine aminotransferase (moderate to low quality evidence). Analysis of 12 RCTs found a beneficial effect of SGLT2-i on HbA1c compared with OAD (-0.20%, -0.28 to -0.13%; moderate quality evidence). Conclusion

  12. An overview of the effect of sodium glucose cotransporter 2 inhibitor monotherapy on glycemic and other clinical laboratory parameters in type 2 diabetes patients

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-07-01

    Full Text Available Yaowen Wang,1 Xueting Hu,2 Xueying Liu,3 Zengqi Wang2 1Department of Clinical Laboratory, Weifang People’s Hospital, 2Department of Clinical Laboratory, Weifang Traditional Chinese Hospital, Weifang, 3Department of Clinical Laboratory, The Third Hospital of Jinan, Jinan, People’s Republic of China Objectives: We aimed to determine the effect of sodium glucose cotransporter 2 (SGLT2 inhibitor monotherapy on glycemic and other clinical laboratory parameters versus other antidiabetic medications or placebo therapy in patients with type 2 diabetes mellitus. In addition, we aimed to investigate the risk of diabetic ketoacidosis associated with SGLT2 inhibitor therapy and evaluate its weight-sparing ability. Design: Meta-analysis. Materials and methods: PubMed and MEDLINE were searched to identify eligible studies up to December 2015. Randomized controlled trials that assessed the efficacy and safety of SGLT2 inhibitor monotherapy versus placebo therapy or active control were considered. The Cochrane Collaboration Risk of Bias Tool was used to evaluate quality and bias. The mean ­difference was used to evaluate the glycemic and other clinical laboratory parameters for SGLT2 inhibitor intervention versus control by drugs or placebo. Similarly, the risk ratio was used to assess adverse events, and the I2 was used to evaluate heterogeneity. Results: SGLT2 inhibitors significantly decreased glycated hemoglobin (HbA1c (P<0.001, weight (P<0.001, and the low-density lipoprotein/high-density lipoprotein ratio (P=0.03 compared with placebo therapy. No statistically significant changes were found in fasting plasma glucose, 2-hour postprandial glucose, or lipid parameters. Significant changes in the uric acid level were found for SGLT2 inhibitors versus placebo therapy (P=0.005 or active control (P<0.001. Although no significant change in levels of ketones occurred (P=0.93, patients receiving SGLT2 inhibitors were at greater risk of increased ketone bodies

  13. Integrated responses of Na+/HCO3- cotransporters and V-type H+-ATPases in the fish gill and kidney during respiratory acidosis.

    Science.gov (United States)

    Perry, S F; Furimsky, M; Bayaa, M; Georgalis, T; Shahsavarani, A; Nickerson, J G; Moon, T W

    2003-12-30

    Using degenerate primers, followed by 3' and 5' RACE and "long" PCR, a continuous 4050-bp cDNA was obtained and sequenced from rainbow trout (Oncorhynchus mykiss) gill. The cDNA included an open reading frame encoding a deduced protein of 1088 amino acids. A BLAST search of the GenBank protein database demonstrated that the trout gene shared high sequence similarity with several vertebrate Na(+)/HCO(3)(-) cotransporters (NBCs) and in particular, NBC1. Protein alignment revealed that the trout NBC is >80% identical to vertebrate NBC1s and phylogenetic analysis provided additional evidence that the trout NBC is indeed a homolog of NBC1. Using the same degenerate primers, a partial cDNA (404 bp) for NBC was obtained from eel (Anguilla rostrata) kidney. Analysis of the tissue distribution of trout NBC, as determined by Northern blot analysis and real-time PCR, indicated high transcript levels in several absorptive/secretory epithelia including gill, kidney and intestine and significant levels in liver. NBC mRNA was undetectable in eel gill by real-time PCR. In trout, the levels of gill NBC1 mRNA were increased markedly during respiratory acidosis induced by exposure to hypercarbia; this response was accompanied by a transient increase in branchial V-type H(+)-ATPase mRNA levels. Assuming that the branchial NBC1 is localised to basolateral membranes of gill cells and operates in the influx mode (HCO(3)(-) and Na(+) entry into the cell), it would appear that in trout, the expression of branchial NBC1 is transcriptionally regulated to match the requirements of gill pHi regulation rather than to match trans-epithelial HCO(3)(-) efflux requirements for systemic acid-base balance. By analogy with mammalian systems, NBC1 in the kidney probably plays a role in the tubular reabsorption of both Na(+) and HCO(3)(-). During periods of respiratory acidosis, levels of renal NBC1 mRNA increased (after a transient reduction) in both trout and eel, presumably to increase HCO(3

  14. Na+, HCO3--cotransporter NBCn1 increases pHi gradients, filopodia, and migration of smooth muscle cells and promotes arterial remodelling.

    Science.gov (United States)

    Boedtkjer, Ebbe; Bentzon, Jacob F; Dam, Vibeke S; Aalkjaer, Christian

    2016-08-01

    Arterial remodelling can cause luminal narrowing and obstruct blood flow. We tested the hypothesis that cellular acid-base transport facilitates proliferation and migration of vascular smooth muscle cells (VSMCs) and enhances remodelling of conduit arteries. [Formula: see text]-cotransport via NBCn1 (Slc4a7) mediates net acid extrusion and controls steady-state intracellular pH (pHi) in VSMCs of mouse carotid arteries and primary aortic explants. Carotid arteries undergo hypertrophic inward remodelling in response to partial or complete ligation in vivo, but the increase in media area and thickness and reduction in lumen diameter are attenuated in arteries from NBCn1 knock-out compared with wild-type mice. With [Formula: see text] present, gradients for pHi (∼0.2 units magnitude) exist along the axis of VSMC migration in primary explants from wild-type but not NBCn1 knock-out mice. Knock-out or pharmacological inhibition of NBCn1 also reduces filopodia and lowers initial rates of VSMC migration after scratch-wound infliction. Interventions to reduce H(+)-buffer mobility (omission of [Formula: see text] or inhibition of carbonic anhydrases) re-establish axial pHi gradients, filopodia, and migration rates in explants from NBCn1 knock-out mice. The omission of [Formula: see text] also lowers global pHi and inhibits proliferation in primary explants. Under physiological conditions (i.e. with [Formula: see text] present), NBCn1-mediated [Formula: see text] uptake raises VSMC pHi and promotes filopodia, VSMC migration, and hypertrophic inward remodelling. We propose that axial pHi gradients enhance VSMC migration whereas global acidification inhibits VSMC proliferation and media hypertrophy after carotid artery ligation. These findings support a key role of acid-base transport, particularly via NBCn1, for development of occlusive artery disease. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please

  15. Clinical profile of patients with type 2 diabetes mellitus treated with sodium- glucose cotransporter-2 inhibitors and experience in real-world clinical practice in Spain.

    Science.gov (United States)

    Cuatrecasas, Gabriel; Goñi-Goicoechea, Fernando

    2016-11-01

    The main aim of the treatment of type 2 diabetes is overall control of cardiovascular risk factors. Almost 50% of patients with type 2 diabetes do not achieve glycaemic targets, and a much higher percentage do not achieve weight and blood pressure targets, despite the therapeutic arsenal that has appeared in the last decade for the treatment of this disease. In addition, antidiabetic secretatogues and insulin are associated with weight gain and an increased risk of hyperglycaemic episodes. Clinical practice guidelines recommend sodium-glucose cotransporter-2 inhibitors (SGLT2i) as an alternative in the same therapeutic step as the other options after initiation of metformin therapy. The present study reviews the most appropriate patient profile for SGLT2i therapy, based on their safety and efficacy demonstrated in controlled clinical trials. The article discusses which patients are at risk of experiencing the possible secondary effects due to the mechanism of action of this new therapeutic class, in whom SGLT2i should be used with caution. These considerations on the profile of patients suitable for SGLT2i therapy are contrasted with the results obtained in daily clinical practice, both in retrospective studies from other countries and from real-world experiences in Spain. This article presents a selection of studies performed in distinct centres with a minimum follow-up of 6 months and compares their results with those from clinical trials. SGLT2i are used in clinical practice in any therapeutic step and the efficacy results are very similar to those reported by controlled clinical trials, with a slightly higher proportion of genitourinary infections and a low dropout rate. Half the reported patients are diabetics receiving insulin therapy plus a gliflozin, showing the wide uptake of this therapeutic strategy by clinicians. SGLT2i are especially attractive due to their additional effectiveness in weight and blood pressure control and the possibility of using them

  16. Na+-taurocholate cotransporting polypeptide (NTCP/SLC10A1) ortholog in the marine skate Leucoraja erinacea is not a physiological bile salt transporter.

    Science.gov (United States)

    Yu, Dongke; Zhang, Han; Lionarons, Daniel A; Boyer, James L; Cai, Shi-Ying

    2017-04-01

    The Na + -dependent taurocholate cotransporting polypeptide (NTCP/SLC10A1) is a hepatocyte-specific solute carrier, which plays an important role in maintaining bile salt homeostasis in mammals. The absence of a hepatic Na + -dependent bile salt transport system in marine skate and rainbow trout raises a question regarding the function of the Slc10a1 gene in these species. Here, we have characterized the Slc10a1 gene in the marine skate, Leucoraja erinacea The transcript of skate Slc10a1 (skSlc10a1) encodes 319 amino acids and shares 46% identity to human NTCP (hNTCP) with similar topology to mammalian NTCP. SkSlc10a1 mRNA was mostly confined to the brain and testes with minimal expression in the liver. An FXR-bile salt reporter assay indicated that skSlc10a1 transported taurocholic acid (TCA) and scymnol sulfate, but not as effectively as hNTCP. An [ 3 H]TCA uptake assay revealed that skSlc10a1 functioned as a Na + -dependent transporter, but with low affinity for TCA ( K m = 92.4 µM) and scymnol sulfate ( K i = 31 µM), compared with hNTCP (TCA, K m = 5.4 µM; Scymnol sulfate, K i = 3.5 µM). In contrast, the bile salt concentration in skate plasma was 2 µM, similar to levels seen in mammals. Interestingly, skSlc10a1 demonstrated transport activity for the neurosteroids dehydroepiandrosterone sulfate and estrone-3-sulfate at physiological concentration, similar to hNTCP. Together, our findings indicate that skSlc10a1 is not a physiological bile salt transporter, providing a molecular explanation for the absence of a hepatic Na + -dependent bile salt uptake system in skate. We speculate that Slc10a1 is a neurosteroid transporter in skate that gained its substrate specificity for bile salts later in vertebrate evolution. Copyright © 2017 the American Physiological Society.

  17. Sodium-glucose co-transporter-2 inhibitors, the latest residents on the block: Impact on glycaemic control at a general practice level in England.

    Science.gov (United States)

    Heald, Adrian H; Fryer, Anthony A; Anderson, Simon G; Livingston, Mark; Lunt, Mark; Davies, Mark; Moreno, Gabriela Y C; Gadsby, Roger; Young, Robert J; Stedman, Mike

    2018-03-08

    To determine, using published general practice-level data, how differences in Type 2 diabetes mellitus (T2DM) prescribing patterns relate to glycaemic target achievement levels. Multiple linear regression modelling was used to link practice characteristics and defined daily dose (DDD) of different classes of medication in 2015/2016 and changes between that year and the year 2014/2015 in medication to proportion of patients achieving target glycaemic control (glycated haemoglobin A1c [HbA1c] ≤58 mmol/mol [7.5%]) and proportion of patients at high glycaemic risk (HbA1c >86 mmol/mol [10.0%]) for practices in the National Diabetes Audit with >100 people with T2DM on their register. Overall, HbA1c outcomes were not different between the years studied. Although, in percentage terms, most practices increased their use of sodium-glucose co-transporter-2 (SGLT2) inhibitors (96%), dipeptidyl peptidase-4 (DPP-4) inhibitors (76%) and glucagon-like peptide 1 (GLP-1) analogues (53%), there was wide variation in the use of older and newer therapies. For example, 12% of practices used >200% of the national average for some newer agents. In cross-sectional analysis, greater prescribing of metformin and analogue insulin were associated with a higher proportion of patients achieving HbA1c ≤58 mmol/mol; the use of SGLT2 inhibitors and metformin was associated with a reduced proportion of patients with HbA1c >86 mol/mol; otherwise associations for sulphonylureas, GLP-1 analogues, SGLT2 inhibitors and DPP-4 inhibitors were neutral or negative. In year-on-year analysis there was ongoing deterioration in glycaemic control, which was offset to some extent by increased use of SGLT2 inhibitors and GLP-1 analogues, which were associated with a greater proportion of patients achieving HbA1c levels ≤58 mmol/mol and a smaller proportion of patients with HbA1c levels >86 mmol/mol. SGLT2 inhibitor prescribing was associated with significantly greater improvements than those found

  18. Differential expression of gill Na+,K+-ATPase alpha- and beta-subunits, Na+,K+,2Cl- cotransporter and CFTR anion channel in juvenile anadromous and landlocked Atlantic salmon Salmo salar

    DEFF Research Database (Denmark)

    Nilsen, Tom O.; Ebbesson, Lars O. E.; Madsen, Steffen S.

    2007-01-01

    This study examines changes in gill Na(+),K(+)-ATPase (NKA) alpha- and beta-subunit isoforms, Na(+),K(+),2Cl(-) cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR I and II) in anadromous and landlocked strains of Atlantic salmon during parr-smolt transformation, an...

  19. The Na+/H+ exchanger NHE1, but not the Na+, HCO3- cotransporter NBCn1, regulates motility of MCF7 breast cancer cells expressing constitutively active ErbB2

    DEFF Research Database (Denmark)

    Lauritzen, Gitte; Stock, Christian-Martin; Lemaire, Justine

    2012-01-01

    We and others have shown central roles of the Na(+)/H(+) exchanger NHE1 in cell motility. The aim of this study was to determine the roles of NHE1 and of the Na(+), HCO(3)(-) cotransporter NBCn1 in motility of serum-starved MCF-7 breast cancer cells expressing constitutively active ErbB2 (¿NErbB2...

  20. Effect of Sodium-Glucose Cotransport-2 Inhibitors on Blood Pressure in People With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of 43 Randomized Control Trials With 22 528 Patients.

    Science.gov (United States)

    Mazidi, Mohsen; Rezaie, Peyman; Gao, Hong-Kai; Kengne, Andre Pascal

    2017-05-25

    The sodium-glucose cotransporter 2 (SGLT2) inhibitors are a class of oral hypoglycemic agents. We undertake a systematic review and meta-analysis of prospective studies to determine the effect of SGLT2 on blood pressure (BP) among individuals with type 2 diabetes mellitus. PubMed-Medline, Web of Science, Cochrane Database, and Google Scholar databases were searched to identify trial registries evaluating the impact of SGLT2 on BP. Random-effects models meta-analysis was used for quantitative data synthesis. The meta-analysis indicated a significant reduction in systolic BP following treatment with SGLT2 (weighted mean difference -2.46 mm Hg [95% CI -2.86 to -2.06]). The weighted mean differences for the effect on diastolic BP was -1.46 mm Hg (95% CI -1.82 to -1.09). In these subjects the weighted mean difference effects on serum triglycerides and total cholesterol were -2.08 mg/dL (95% CI -2.51 to -1.64) and 0.77 mg/dL (95% CI 0.33-1.21), respectively. The weighted mean differences for the effect of SGLT2 on body weight was -1.88 kg (95% CI -2.11 to -1.66) across all studies. These findings were robust in sensitivity analyses. Treatment with SGLT2 glucose cotransporter inhibitors therefore has beneficial off-target effects on BP in patients with type 2 diabetes mellitus and may also be of value in improving other cardiometabolic parameters including lipid profile and body weight in addition to their expected effects on glycemic control. However, our findings should be interpreted with consideration for the moderate statistical heterogeneity across the included studies. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  1. Effects of antidiabetic drugs on the incidence of macrovascular complications and mortality in type 2 diabetes mellitus: a new perspective on sodium-glucose co-transporter 2 inhibitors.

    Science.gov (United States)

    Rahelić, Dario; Javor, Eugen; Lucijanić, Tomo; Skelin, Marko

    2017-02-01

    Elevated hemoglobin A 1c (HbA 1c ) values correlate with microvascular and macrovascular complications. Thus, patients with type 2 diabetes mellitus (T2DM) are at an increased risk of developing macrovascular events. Treatment of T2DM should be based on a multifactorial approach because of its evidence regarding reduction of macrovascular complications and mortality in T2DM. It is well known that intensive glucose control reduces the risk of microvascular complications in T2DM, but the effects of antidiabetic drugs on macrovascular complications and mortality in T2DM are less clear. The results of recent trials have demonstrated clear evidence that empagliflozin and liraglutide reduce cardiovascular (CV) and all-cause mortality in T2DM, an effect that is absent in other members of antidiabetic drugs. Empagliflozin is a member of a novel class of antidiabetic drugs, the sodium-glucose co-transporter 2 (SGLT2) inhibitors. Two ongoing randomized clinical trials involving other SGLT2 inhibitors, canagliflozin and dapagliflozin, will provide additional evidence of the beneficial effects of SGLT2 inhibitors in T2DM population. The aim of this paper is to systematically present the latest evidence regarding the usage of antidiabetic drugs, and the reduction of macrovascular complications and mortality. A special emphasis is put on the novel class of antidiabetic drugs, of SGLT2 inhibitors. Key messages Macrovascular complications and mortality are best clinical trial endpoints for evaluating the efficacy of antidiabetic drugs. The first antidiabetic drug that demonstrated a reduction in mortality in the treatment of type 2 diabetes mellitus (T2DM) was empagliflozin, a sodium-glucose co-transporter 2 (SGLT2) inhibitor. SGLT2 inhibitors are novel class of antidiabetic drugs that play a promising role in the treatment of T2DM.

  2. Changes in glucose-induced plasma active glucagon-like peptide-1 levels by co-administration of sodium–glucose cotransporter inhibitors with dipeptidyl peptidase-4 inhibitors in rodents

    Directory of Open Access Journals (Sweden)

    Takahiro Oguma

    2016-12-01

    Full Text Available We investigated whether structurally different sodium–glucose cotransporter (SGLT 2 inhibitors, when co-administered with dipeptidyl peptidase-4 (DPP4 inhibitors, could enhance glucagon-like peptide-1 (GLP-1 secretion during oral glucose tolerance tests (OGTTs in rodents. Three different SGLT inhibitors—1-(β-d-Glucopyranosyl-4-chloro-3-[5-(6-fluoro-2-pyridyl-2-thienylmethyl]benzene (GTB, TA-1887, and canagliflozin—were examined to assess the effect of chemical structure. Oral treatment with GTB plus a DPP4 inhibitor enhanced glucose-induced plasma active GLP-1 (aGLP-1 elevation and suppressed glucose excursions in both normal and diabetic rodents. In DPP4-deficient rats, GTB enhanced glucose-induced aGLP-1 elevation without affecting the basal level, whereas metformin, previously reported to enhance GLP-1 secretion, increased both the basal level and glucose-induced elevation. Oral treatment with canagliflozin and TA-1887 also enhanced glucose-induced aGLP-1 elevation when co-administered with either teneligliptin or sitagliptin. These data suggest that structurally different SGLT2 inhibitors enhance plasma aGLP-1 elevation and suppress glucose excursions during OGTT when co-administered with DPP4 inhibitors, regardless of the difference in chemical structure. Combination treatment with DPP4 inhibitors and SGLT2 inhibitors having moderate SGLT1 inhibitory activity may be a promising therapeutic option for improving glycemic control in patients with type 2 diabetes mellitus.

  3. Effects of cortisol and salinity acclimation on Na+/K+/2Cl–- cotransporter gene expression and Na+, K+-ATPase activity in the gill of Persian sturgeon, Acipenser persicus, fry

    Directory of Open Access Journals (Sweden)

    Saber Khodabandeh

    2009-10-01

    Full Text Available Na+, K+-ATPase activity and Na+/K+/2Cl–- cotransporter (NKCC gene expression in the gills of Persian sturgeon, Acipenser persicus, fry (2-3 g, 3.30-8.12 cm total body length in freshwater (control group, diluted Caspian Sea water (5 ppt and after treatment with cortisol in freshwater were studied. Na+, K+-ATPase activity was lower in the 5 ppt-acclimated fish (1.07±0.05 _mol Pi/mg protein/h than in the control fish (1.19±0.05 μmol Pi/mg protein/h but this difference was not significant. nKCC gene expression in the 5 ppt-acclimated fish (1.6±0.07 was significantly higher than in the control fish (0.8±0.00. In the cortisol treated fish, Na+, K+-ATPase activity (1.91±0.05 μmol Pi/mg protein/h and NKCC gene expression (3.2±0.1 were significantly higher than in the control group. our results show that Persian sturgeon fry (2-3 g can tolerate 5 ppt salinity by changing their enzymatic content and activity, and that exogenous cortisol application can increase the osmoregulatory capacity of fry before release into brackish water and can reduce their mortality.

  4. Altered Regulation of type 3 Na+/H+ exchanger, type 1 Na+/HCO3- cotransporter, and Na+,K+-ATPase in the Kidney of Rats with Experimental Rhabdomyolysis

    Science.gov (United States)

    Ma, Seong Kwon; Bae, Eun Hui; Lee, JongUn; Kim, Sun Young; Kim, Sung Zoo; Choi, Ki Chul

    2007-01-01

    Metabolic acidosis was shown to correlate with deterioration of renal function in patients with rhabdomyolysis. The present study was aimed to investigate whether the changes of type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), and Na+,K+-ATPase α1 subunit may play a role in the pathogenesis of metabolic acidosis in glycerol-induced experimental rhabdomyolysis. Male Sprague-Dawley rats were deprived of fluid intake for 24 hours, and then were injected with 50% glycerol in normal saline (10 mL/kg, intramuscularly). At 24 hours after the glycerol injection, rats were sacrificed by decapitation. Control rats were injected with normal saline. The protein expression of NHE3, NBC1 and Na+,K+-ATPase α1 subunit was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Following the treatment of glycerol, creatinine clearance was significantly decreased, and high anion gap metabolic acidosis developed. In the experimental group, the expression of Na+,K+-ATPase α1 subunit was significantly decreased in the cortex of the kidney. On the contrary, the expression of NHE3 and NBC1 was significantly increased. Immunohistochemical analyses confirmed the immunoblotting data. In conclusion, the coordinate up-regulation of NHE3 and NBC1 may play an adaptive role against the metabolic acidosis in glycerol-induced rhabdomyolysis. PMID:24459502

  5. Lack of evidence for a harmful effect of sodium-glucose co-transporter 2 (SGLT2) inhibitors on fracture risk among type 2 diabetes patients: a network and cumulative meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Tang, H L; Li, D D; Zhang, J J; Hsu, Y H; Wang, T S; Zhai, S D; Song, Y Q

    2016-12-01

    To evaluate the comparative effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on risk of bone fracture in patients with type 2 diabetes mellitus (T2DM). PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were systematically searched from inception to 27 January 2016 to identify randomized controlled trials (RCTs) reporting the outcome of fracture in patients with T2DM treated with SGLT2 inhibitors. Pairwise and network meta-analyses, as well as a cumulative meta-analysis, were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). A total of 38 eligible RCTs (10 canagliflozin, 15 dapagliflozin and 13 empagliflozin) involving 30 384 patients, with follow-ups ranging from 24 to 160 weeks, were included. The fracture event rates were 1.59% in the SGLT2 inhibitor groups and 1.56% in the control groups. The incidence of fracture events was similar among these three SGLT2 inhibitor groups. Compared with placebo, canagliflozin (OR 1.15; 95% CI 0.71-1.88), dapagliflozin (OR 0.68; 95% CI 0.37-1.25) and empagliflozin (OR 0.93; 95% CI 0.74-1.18) were not significantly associated with an increased risk of fracture. Our cumulative meta-analysis indicated the robustness of the null findings with regard to SGLT2 inhibitors. Our meta-analysis based on available RCT data does not support the harmful effect of SGLT2 inhibitors on fractures, although future safety monitoring from RCTs and real-world data with detailed information on bone health is warranted. © 2016 John Wiley & Sons Ltd.

  6. Effects of low environmental salinity on the cellular profiles and expression of Na+, K+-ATPase and Na+, K+, 2Cl- cotransporter 1 of branchial mitochondrion-rich cells in the juvenile marine fish Monodactylus argenteus.

    Science.gov (United States)

    Kang, Chao-Kai; Liu, Fu-Chen; Chang, Wen-Been; Lee, Tsung-Han

    2012-06-01

    The goal of this study was to determine the osmoregulatory ability of a juvenile marine fish, silver moony (Monodactylus argenteus), for the purpose of developing a new experimental species for ecophysiological research. In this study, M. argenteus was acclimated to freshwater (FW), brackish water (BW), or seawater (SW). The salinity tolerance of this euryhaline species was effective, and the fish survived well upon osmotic challenges. The largest apical surface of mitochondrion-rich cells was found in the FW individuals. Immunohistochemical staining revealed that Na(+), K(+)-ATPase immunoreactive (NKA-IR) cells were distributed in the interlamellar region of the gill filaments of the silver moony in all experimental groups. In addition to the filaments, NKA-IR cells were also found in the lamellae of the FW individuals. The number of NKA-IR cells in the gills of the FW individuals exceeded that of the BW and SW individuals. The NKA-IR cells of FW and SW individuals exhibited bigger size than that of BW fish. The NKA activities and protein expression of the NKA α-subunit in the gills of the FW individuals were significantly higher than in the BW and SW groups. Additionally, the relative amounts of Na(+), K(+), 2Cl(-) cotransporter 1 (NKCC1) were salinity-dependent in the gills. Immunofluorescent signals of NKCC1 were localized to the basolateral membrane of NKA-IR cells in all groups. In the gills of the FW individuals, however, some NKA-IR cells did not exhibit a basolateral NKCC1 signal. In conclusion, the present study illustrated the osmoregulatory mechanisms of this easy- and economic-to-rear marine teleost with euryhaline capacity and proved the silver moony to be a good experimental animal.

  7. Functional classification of mitochondrion-rich cells in euryhaline Mozambique tilapia (Oreochromis mossambicus) embryos, by means of triple immunofluorescence staining for Na+/K+-ATPase, Na +/K+/2Cl- cotransporter and CFTR anion channel

    Science.gov (United States)

    Hiroi, J.; McCormick, S.D.; Ohtani-Kaneko, R.; Kaneko, T.

    2005-01-01

    Mozambique tilapia Oreochromis mossambicus embryos were transferred from freshwater to seawater and vice versa, and short-term changes in the localization of three major ion transport proteins, Na+/K +-ATPase, Na+/K+/2Cl- cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR) were examined within mitochondrion-rich cells (MRCs) in the embryonic yolk-sac membrane. Triple-color immunofluorescence staining allowed us to classify MRCs into four types: type I, showing only basolateral Na+/K +-ATPase staining; type II, basolateral Na+/K +-ATPase and apical NKCC; type III, basolateral Na+/K +-ATPase and basolateral NKCC; type IV, basolateral Na +/K+-ATPase, basolateral NKCC and apical CFTR. In freshwater, type-I, type-II and type-III cells were observed. Following transfer from freshwater to seawater, type-IV cells appeared at 12 h and showed a remarkable increase in number between 24 h and 48 h, whereas type-III cells disappeared. When transferred from seawater back to freshwater, type-IV cells decreased and disappeared at 48 h, type-III cells increased, and type-II cells, which were not found in seawater, appeared at 12 h and increased in number thereafter. Type-I cells existed consistently irrespective of salinity changes. These results suggest that type I is an immature MRC, type II is a freshwater-type ion absorptive cell, type III is a dormant type-IV cell and/or an ion absorptive cell (with a different mechanism from type II), and type IV is a seawater-type ion secretory cell. The intracellular localization of the three ion transport proteins in type-IV cells is completely consistent with a widely accepted model for ion secretion by MRCs. A new model for ion absorption is proposed based on type-II cells possessing apical NKCC.

  8. Effectiveness of Sodium-Glucose Cotransporter-2 Inhibitor as an Add-on Drug to GLP-1 Receptor Agonists for Glycemic Control of a Patient with Prader-Willi Syndrome: A Case Report.

    Science.gov (United States)

    Horikawa, Yukio; Enya, Mayumi; Komagata, Makie; Hashimoto, Ken-Ichi; Kagami, Masayo; Fukami, Maki; Takeda, Jun

    2018-02-01

    Diabetes patients with Prader-Willi syndrome (PWS) are obese because of hyperphagia; weight control by dietary modification and medicine is required for glycemic control. There are several recent reports showing the effectiveness of GLP-1 receptor agonists (GLP-1RAs) for diabetes treatment in PWS. A 36-year-old Japanese male patient was diagnosed with PWS at 10 years of age. At age 16 years, he was diagnosed with diabetes and began to take several kinds of oral hypoglycemic agents. At age 29 years, his BMI was 39.1 kg/m 2 and he was referred to our department for diabetes and obesity treatment. In the present case, the HbA1c was not improved by GLP-1RAs despite a 28-kg BW reduction, which included a 9-kg loss of muscle. Apprehensive of further loss of muscle mass, basal insulin of insulin glargine was administered in addition to GLP-1RAs. Immediately after the addition of tofogliflozin, a sodium-glucose cotransporter-2 (SGLT2) inhibitor, the patient's HbA1c decreased dramatically with only about an additional 3% BW reduction. We note an improvement in our case of lipid deposition in the pancreas confirmed by abdominal CT after the improvement of HbA1c. It is unknown whether this improvement of fatty pancreas was a cause or an effect of the improved glycemic control in the present case. This finding clearly supports the effectiveness of combining SGLT2 inhibitors with GLP-1RAs for treatment of patients with PWS and non-alcoholic fatty pancreas disease.

  9. Renal-Specific Silencing of TNF (Tumor Necrosis Factor) Unmasks Salt-Dependent Increases in Blood Pressure via an NKCC2A (Na+-K+-2Cl- Cotransporter Isoform A)-Dependent Mechanism.

    Science.gov (United States)

    Hao, Shoujin; Hao, Mary; Ferreri, Nicholas R

    2018-06-01

    We tested the hypothesis that TNF (tumor necrosis factor)-α produced within the kidney and acting on the renal tubular system is part of a regulatory mechanism that attenuates increases in blood pressure in response to high salt intake. Intrarenal administration of a lentivirus construct, which specifically silenced TNF in the kidney, did not affect baseline blood pressure. However, blood pressure increased significantly 1 day after mice with intrarenal silencing of TNF ingested 1% NaCl in the drinking water. The increase in blood pressure, which was continuously observed for 11 days, promptly returned to baseline levels when mice were switched from 1% NaCl to tap water. Silencing of renal TNF also increased NKCC2 (Na + -K + -2Cl - cotransporter) phosphorylation and induced a selective increase in NKCC2A (NKCC2 isoform A) mRNA accumulation in both the cortical and medullary thick ascending limb of Henle loop that was neither associated with a compensatory decrease of NKCC2F in the medulla nor NKCC2B in the cortex. The NaCl-mediated increases in blood pressure were completely absent when NKCC2A, using a lentivirus construct that did not alter expression of NKCC2F or NKCC2B, and TNF were concomitantly silenced in the kidney. Moreover, the decrease in urine volume and NaCl excretion induced by renal TNF silencing was abolished when NKCC2A was concurrently silenced, suggesting that this isoform contributes to the transition from a salt-resistant to salt-sensitive phenotype. Collectively, the data are the first to demonstrate a role for TNF produced by the kidney in the modulation of sodium homeostasis and blood pressure regulation. © 2018 American Heart Association, Inc.

  10. TGF-β signaling directly regulates transcription and functional expression of the electrogenic sodium bicarbonate cotransporter 1, NBCe1 (SLC4A4), via Smad4 in mouse astrocytes.

    Science.gov (United States)

    Khakipoor, Shokoufeh; Ophoven, Christian; Schrödl-Häußel, Magdalena; Feuerstein, Melanie; Heimrich, Bernd; Deitmer, Joachim W; Roussa, Eleni

    2017-08-01

    The electrogenic sodium bicarbonate cotransporter NBCe1 (SLC4A4) expressed in astrocytes regulates intracellular and extracellular pH. Here, we introduce transforming growth factor beta (TGF-β) as a novel regulator of NBCe1 transcription and functional expression. Using hippocampal slices and primary hippocampal and cortical astrocyte cultures, we investigated regulation of NBCe1 and elucidated the underlying signaling pathways by RT-PCR, immunoblotting, immunofluorescence, intracellular H( + ) recording using the H( + ) -sensitive dye 2',7'-bis-(carboxyethyl)-5-(and-6)-carboxyfluorescein, mink lung epithelial cell (MLEC) assay, and chromatin immunoprecipitation. Activation of TGF-β signaling significantly upregulated transcript, protein, and surface expression of NBCe1. These effects were TGF-β receptor-mediated and suppressed following inhibition of JNK and Smad signaling. Moreover, 4-aminopyridine (4AP)-dependent NBCe1 regulation requires TGF-β. TGF-β increased the rate and amplitude of intracellular H + changes upon challenging NBCe1 in wild-type astrocytes but not in cortical astrocytes from Slc4a4-deficient mice. A Smad4 binding sequence was identified in the NBCe1 promoter and Smad4 binding increased after activation of TGF-β signaling. The data show for the first time that NBCe1 is a direct target of TGF-β/Smad4 signaling. Through activation of the canonical pathway TGF-β acts directly on NBCe1 by binding of Smad4 to the NBCe1 promoter and regulating its transcription, followed by increased protein expression and transport activity. © 2017 The Authors GLIA Published by Wiley Periodicals, Inc.

  11. Effects of sodium-glucose co-transporter 2 (SGLT2 inhibition on renal function and albuminuria in patients with type 2 diabetes: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Lubin Xu

    2017-06-01

    Full Text Available Aim To evaluate the effects of sodium-glucose co-transporter 2 (SGLT2 inhibition on renal function and albuminuria in patients with type 2 diabetes. Methods We conducted systematic searches of PubMed, Embase and Cochrane Central Register of Controlled Trials up to June 2016 and included randomized controlled trials of SGLT2 inhibitors in adult type 2 diabetic patients reporting estimated glomerular filtration rate (eGFR and/or urine albumin/creatinine ratio (ACR changes. Data were synthesized using the random-effects model. Results Forty-seven studies with 22,843 participants were included. SGLT2 inhibition was not associated with a significant change in eGFR in general (weighted mean difference (WMD, −0.33 ml/min per 1.73 m2, 95% CI [−0.90 to 0.23] or in patients with chronic kidney disease (CKD (WMD −0.78 ml/min per 1.73 m2, 95% CI [−2.52 to 0.97]. SGLT2 inhibition was associated with eGFR reduction in short-term trials (WMD −0.98 ml/min per 1.73 m2, 95% CI [−1.42 to −0.54], and with eGFR preservation in long-term trials (WMD 2.01 ml/min per 1.73 m2, 95% CI [0.86 to 3.16]. Urine ACR reduction after SGLT2 inhibition was not statistically significant in type 2 diabetic patients in general (WMD −7.24 mg/g, 95% CI [−15.54 to 1.06], but was significant in patients with CKD (WMD −107.35 mg/g, 95% CI [−192.53 to −22.18]. Conclusions SGLT2 inhibition was not associated with significant changes in eGFR in patients with type 2 diabetes, likely resulting from a mixture of an initial reduction of eGFR and long-term renal function preservation. SGLT2 inhibition was associated with statistically significant albuminuria reduction in type 2 diabetic patients with CKD.

  12. Characterizing and evaluating the expression of the type IIb sodium-dependent phosphate cotransporter (slc34a2) gene and its potential influence on phosphorus utilization efficiency in yellow catfish (Pelteobagrus fulvidraco).

    Science.gov (United States)

    Chen, Pei; Tang, Qin; Wang, Chunfang

    2016-02-01

    A sodium-dependent phosphate cotransporter gene, NaPi-IIb (slc34a2), was isolated from yellow catfish (Pelteobagrus fulvidraco) intestine through homology cloning and the rapid amplification of cDNA ends. The full-length cDNA of slc34a2 consisted of 2326 bp with an open reading frame encoding 621 amino acids, a 160-bp 5' untranslated region, and a 300-bp 3' untranslated region. The deduced amino acid sequence showed 79.0 and 70.9% sequence identity to Astyanax mexicanus and Pundamilia nyererei, respectively. The membrane-spanning domains based on the hydrophilic and hydrophobic properties of the deduced amino acids were predicted, and results showed that the putative protein had eight transmembrane domains, with the intracellular NH2 and COOH termini. Two functional regions including first intracellular loop and third extracellular loop as well as the six N-glycosylation sites in second extracellular loop were found. The slc34a2 mRNA in the tested tissues was examined through semiquantitative reverse transcription polymerase chain reaction and quantitative real-time PCR, with the highest level found in the anterior intestine, followed by the posterior and middle intestines. The slc34a2 mRNA expression in the whole intestine under different dietary phosphorus (P) treatments was detected using qPCR. The results showed that the slc34a2 expression levels in the low-P groups (0.33 and 0.56%) were significantly higher (p < 0.05) than levels in the sufficient-P (0.81%) and high-P (1.15, 1.31, and 1.57%) groups. High expression of slc34a2 mRNA in low-P groups stimulated P utilization efficiency, indicating the close relationship between genotype and phenotype in yellow catfish. In contrast with conventional strategies (formula and feeding strategies), this study provided another possible approach by using molecular techniques to increase the P utilization in yellow catfish.

  13. High Brain Ammonia Tolerance and Down-Regulation of Na+:K+:2Cl- Cotransporter 1b mRNA and Protein Expression in the Brain of the Swamp Eel, Monopterus albus, Exposed to Environmental Ammonia or Terrestrial Conditions

    Science.gov (United States)

    Ip, Yuen K.; Hou, Zhisheng; Chen, Xiu L.; Ong, Jasmine L. Y.; Chng, You R.; Ching, Biyun; Hiong, Kum C.; Chew, Shit F.

    2013-01-01

    Na+:K+:2Cl- cotransporter 1 (NKCC1) has been implicated in mediating ischemia-, trauma- or ammonia-induced astrocyte swelling/brain edema in mammals. This study aimed to determine the effects of ammonia or terrestrial exposure on ammonia concentrations in the plasma and brain, and the mRNA expression and protein abundance of nkcc/Nkcc in the brain, of the swamp eel Monopterus albus . Ammonia exposure led to a greater increase in the ammonia concentration in the brain of M. albus than terrestrial exposure. The brain ammonia concentration of M. albus reached 4.5 µmol g-1 and 2.7 µmol g-1 after 6 days of exposure to 50 mmol l-1 NH4Cl and terrestrial conditions, respectively. The full cDNA coding sequence of nkcc1b from M. albus brain comprised 3276 bp and coded for 1092 amino acids with an estimated molecular mass of 119.6 kDa. A molecular characterization indicated that it could be activated through phosphorylation and/or glycosylation by osmotic and/or oxidative stresses. Ammonia exposure for 1 day or 6 days led to significant decreases in the nkcc1b mRNA expression and Nkcc1b protein abundance in the brain of M. albus. In comparison, a significant decrease in nkcc1b mRNA expression was observed in the brain of M. albus only after 6 days of terrestrial exposure, but both 1 day and 6 days of terrestrial exposure resulted in significant decreases in the protein abundance of Nkcc1b. These results are novel because it has been established in mammals that ammonia up-regulates NKCC1 expression in astrocytes and NKCC1 plays an important role in ammonia-induced astrocyte swelling and brain edema. By contrast, our results indicate for the first time that M. albus is able to down-regulate the mRNA and protein expression of nkcc1b/Nkcc1b in the brain when confronted with ammonia toxicity, which could be one of the contributing factors to its extraordinarily high brain ammonia tolerance. PMID:24069137

  14. Renal and Cardiovascular Effects of sodium–glucose cotransporter 2 (SGLT2) inhibition in combination with loop Diuretics in diabetic patients with Chronic Heart Failure (RECEDE-CHF): protocol for a randomised controlled double-blind cross-over trial

    Science.gov (United States)

    Mordi, Natalie A; Mordi, Ify R; Singh, Jagdeep S; Baig, Fatima; Choy, Anna-Maria; McCrimmon, Rory J; Struthers, Allan D; Lang, Chim C

    2017-01-01

    Introduction Type 2 diabetes (T2D) and heart failure (HF) are a frequent combination, where treatment options remain limited. There has been increasing interest around the sodium–glucose cotransporter 2 (SGLT2) inhibitors and their use in patients with HF. Data on the effect of SGLT2 inhibitor use with diuretics are limited. We hypothesise that SGLT2 inhibition may augment the effects of loop diuretics and the benefits of SGLT2 inhibitors may extend beyond those of their metabolic (glycaemic parameters and weight loss) and haemodynamic parameters. The effects of SGLT2 inhibitors as an osmotic diuretic and on natriuresis may underlie the cardiovascular and renal benefits demonstrated in the recent EMPA-REG study. Methods and analysis To assess the effect of SGLT2 inhibitors when used in combination with a loop diuretic, the RECEDE-CHF (Renal and Cardiovascular Effects of SGLT2 inhibition in combination with loop Diuretics in diabetic patients with Chronic Heart Failure) trial is a single-centre, randomised, double-blind, placebo-controlled, cross-over trial conducted in a secondary care setting within NHS Tayside, Scotland. 34 eligible participants, aged between 18 and 80 years, with stable T2D and CHF will be recruited. Renal physiological testing will be performed at two points (week 1 and week 6) on each arm to assess the effect of 25 mg empagliflozin, on the primary and secondary outcomes. Participants will be enrolled in the trial for a total period between 14 and 16 weeks. The primary outcome will assess the effect of empagliflozin versus placebo on urine output. The secondary outcomes are to assess the effect of empagliflozin on glomerular filtration rate, cystatin C, urinary sodium excretion, urinary protein/creatinine ratio and urinary albumin/creatinine ratio when compared with placebo. Ethics and dissemination Ethics approval was obtained by the East of Scotland Research Ethics Service. Results of the trial will be submitted for publication in a peer

  15. Hepatic uptake of conjugated bile acids is mediated by both sodium taurocholate cotransporting polypeptide and organic anion transporting polypeptides and modulated by intestinal sensing of plasma bile acid levels in mice.

    Science.gov (United States)

    Slijepcevic, Davor; Roscam Abbing, Reinout L P; Katafuchi, Takeshi; Blank, Antje; Donkers, Joanne M; van Hoppe, Stéphanie; de Waart, Dirk R; Tolenaars, Dagmar; van der Meer, Jonathan H M; Wildenberg, Manon; Beuers, Ulrich; Oude Elferink, Ronald P J; Schinkel, Alfred H; van de Graaf, Stan F J

    2017-11-01

    The Na + -taurocholate cotransporting polypeptide (NTCP/SLC10A1) is believed to be pivotal for hepatic uptake of conjugated bile acids. However, plasma bile acid levels are normal in a subset of NTCP knockout mice and in mice treated with myrcludex B, a specific NTCP inhibitor. Here, we elucidated which transport proteins mediate the hepatic uptake of conjugated bile acids and demonstrated intestinal sensing of elevated bile acid levels in plasma in mice. Mice or healthy volunteers were treated with myrcludex B. Hepatic bile acid uptake kinetics were determined in wild-type (WT), organic anion transporting polypeptide (OATP) knockout mice (lacking Slco1a/1b isoforms), and human OATP1B1-transgenic mice. Effects of fibroblast growth factor 19 (FGF19) on hepatic transporter mRNA levels were assessed in rat hepatoma cells and in mice by peptide injection or adeno-associated virus-mediated overexpression. NTCP inhibition using myrcludex B had only moderate effects on bile acid kinetics in WT mice, but completely inhibited active transport of conjugated bile acid species in OATP knockout mice. Cholesterol 7α-hydroxylase Cyp7a1 expression was strongly down-regulated upon prolonged inhibition of hepatic uptake of conjugated bile acids. Fgf15 (mouse counterpart of FGF19) expression was induced in hypercholanemic OATP and NTCP knockout mice, as well as in myrcludex B-treated cholestatic mice, whereas plasma FGF19 was not induced in humans treated with myrcludex B. Fgf15/FGF19 expression was induced in polarized human enterocyte-models and mouse organoids by basolateral incubation with a high concentration (1 mM) of conjugated bile acids. NTCP and OATPs contribute to hepatic uptake of conjugated bile acids in mice, whereas the predominant uptake in humans is NTCP mediated. Enterocytes sense highly elevated levels of (conjugated) bile acids in the systemic circulation to induce FGF15/19, which modulates hepatic bile acid synthesis and uptake. (Hepatology 2017;66:1631-1643).

  16. X-ray absorption spectroscopy on phosphoric-salt pellets. Determination of the geometric and electronic structure of metal-oxide doped sodium-phosphate glasses

    International Nuclear Information System (INIS)

    Brendebach, B.

    2004-02-01

    Sodium metaphosphate glasses doped with transition metal oxides show characteristic colors. X-ray absorption spectroscopy (XAS) investigations provide information whether the coloration stems from different electronic transitions or changes in the geometrical structure of the glasses. Even though the violet color of MnO y -doped glasses is considered as an evidence for Mn 3+ -ions, Mn K-XAS reveals that the majority of the manganese ions are in the oxidation state +II and have a mixed coordination of four and six oxygen atoms, respectively. The oxygen coordination around the nickel ions in NiO-doped glasses with different metall oxide concentrations is always six. The change of color from citreous to auburn with increasing nickel oxide content is attributed to a systematic change in the bonding characteristic from mainly ionic-like to a small but significant contribution of covalent-like bonding. Analysis of higher coordination shells provides no indication of the formation of metal oxide clusters. (orig.)

  17. 77 FR 74669 - Draft and Revised Draft Guidances for Industry Describing Product-Specific Bioequivalence...

    Science.gov (United States)

    2012-12-17

    ... Phenoxybenzamine hydrochloride Q Quinine sulfate R Risedronate sodium T Tacrolimus Thalidomide Tinidazole For a... Gabapentin P Piroxicam S Sodium Phosphate, dibasic, anhydrous; sodium phosphate, monobasic, monohydrate [[Page 74670

  18. Reversible effects of acute hypertension on proximal tubule sodium transporters

    DEFF Research Database (Denmark)

    Zhang, Y; Magyar, C E; Norian, J M

    1998-01-01

    Acute hypertension provokes a rapid decrease in proximal tubule sodium reabsorption with a decrease in basolateral membrane sodium-potassium-ATPase activity and an increase in the density of membranes containing apical membrane sodium/hydrogen exchangers (NHE3) [Y. Zhang, A. K. Mircheff, C. B....... Renal cortex lysate was fractionated on sorbitol gradients. Basolateral membrane sodium-potassium-ATPase activity (but not subunit immunoreactivity) decreased one-third to one-half after BP was elevated and recovered after BP was normalized. After BP was elevated, 55% of the apical NHE3 immunoreactivity......, smaller fractions of sodium-phosphate cotransporter immunoreactivity, and apical alkaline phosphatase and dipeptidyl-peptidase redistributed to membranes of higher density enriched in markers of the intermicrovillar cleft (megalin) and endosomes (Rab 4 and Rab 5), whereas density distributions...

  19. Budget-impact model for colonoscopy cost calculation and comparison between 2 litre PEG+ASC and sodium picosulphate with magnesium citrate or sodium phosphate oral bowel cleansing agents.

    Science.gov (United States)

    Gruss, H-J; Cockett, A; Leicester, R J

    2012-01-01

    With the availability of several bowel cleansing agents, physicians and hospitals performing colonoscopies will often base their choice of cleansing agent purely on acquisition cost. Therefore, an easy to use budget impact model has been developed and established as a tool to compare total colon preparation costs between different established bowel cleansing agents. The model was programmed in Excel and designed as a questionnaire evaluating information on treatment costs for a range of established bowel cleansing products. The sum of costs is based on National Health Service reference costs for bowel cleansing products. Estimations are made for savings achievable when using a 2-litre polyethylene glycol with ascorbate components solution (PEG+ASC) in place of other bowel cleansing solutions. Test data were entered into the model to confirm validity and sensitivity. The model was then applied to a set of audit cost data from a major hospital colonoscopy unit in the UK. Descriptive analysis of the test data showed that the main cost drivers in the colonoscopy process are the procedure costs and costs for bed days rather than drug acquisition costs, irrespective of the cleansing agent. Audit data from a colonoscopy unit in the UK confirmed the finding with a saving of £107,000 per year in favour of PEG+ASC when compared to sodium picosulphate with magnesium citrate solution (NaPic+MgCit). For every patient group the model calculated overall cost savings. This was irrespective of the higher drug expenditure associated with the use of PEG+ASC for bowel preparation. Savings were mainly realized through reduced costs for repeat colonoscopy procedures and associated costs, such as inpatient length of stay. The budget impact model demonstrated that the primary cost driver was the procedure cost for colonoscopy. Savings can be realized through the use of PEG+ASC despite higher drug acquisition costs relative to the comparator products. From a global hospital funding perspective, the acquisition costs of bowel preparations should not be used as the primary reason to select the preferred treatment agent, but should be part of the consideration, with an emphasis on the clinical outcome.

  20. X-ray absorption spectroscopy on phosphoric-salt pellets. Determination of the geometric and electronic structure of metal-oxide doped sodium-phosphate glasses; Roentgenabsorptionsspektroskopie an Phosphorsalzperlen. Bestimmung der geometrischen und elektronischen Struktur von metalloxid-dotierten Natriumphosphatglaesern

    Energy Technology Data Exchange (ETDEWEB)

    Brendebach, B.

    2004-02-01

    Sodium metaphosphate glasses doped with transition metal oxides show characteristic colors. X-ray absorption spectroscopy (XAS) investigations provide information whether the coloration stems from different electronic transitions or changes in the geometrical structure of the glasses. Even though the violet color of MnO{sub y}-doped glasses is considered as an evidence for Mn{sup 3+}-ions, Mn K-XAS reveals that the majority of the manganese ions are in the oxidation state +II and have a mixed coordination of four and six oxygen atoms, respectively. The oxygen coordination around the nickel ions in NiO-doped glasses with different metall oxide concentrations is always six. The change of color from citreous to auburn with increasing nickel oxide content is attributed to a systematic change in the bonding characteristic from mainly ionic-like to a small but significant contribution of covalent-like bonding. Analysis of higher coordination shells provides no indication of the formation of metal oxide clusters. (orig.)

  1. Water transport between CNS compartments: contributions of aquaporins and cotransporters

    DEFF Research Database (Denmark)

    MacAulay, N; Zeuthen, T

    2010-01-01

    or hydrocephalus. The molecular pathways by which water molecules cross the cell membranes of the brain are not well-understood, although the discovery of aquaporin 4 (AQP4) in the brain improved our understanding of some of these transport processes, particularly under pathological conditions. In the present...

  2. Chloride cotransport in the membrane of earthworm body wall muscles

    Czech Academy of Sciences Publication Activity Database

    Volkov, E. M.; Nurullin, L. F.; Nikolsky, E.; Krůšek, Jan; Vyskočil, František

    2003-01-01

    Roč. 52, č. 5 (2003), s. 587-592 ISSN 0862-8408 R&D Projects: GA ČR GA305/02/1333; GA ČR GA202/02/1213 Grant - others:RBRF(RU) 98-04-48044; RBRF(RU) 99-04-48286; RBRF(RU) 99-04-4306 Institutional research plan: CEZ:AV0Z5011922 Keywords : earthworm * ouabain * furosemide Subject RIV: ED - Physiology Impact factor: 0.939, year: 2003

  3. Drug: D04402 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available D04402 Mixture ... Drug Sodium bicarbonate - anhydrous monobasic sodium phosphate mi...xt; New Lecicarbon (TN) Sodium bicarbonate [DR:D01203], Anhydrous monobasic sodium phosphate [DR:D04400] ... Therapeutic category: 2359 ... PubChem: 17398094 ...

  4. Renal tubular NHE3 is required in the maintenance of water and sodium chloride homeostasis.

    Science.gov (United States)

    Fenton, Robert A; Poulsen, Søren B; de la Mora Chavez, Samantha; Soleimani, Manoocher; Dominguez Rieg, Jessica A; Rieg, Timo

    2017-08-01

    The sodium/proton exchanger isoform 3 (NHE3) is expressed in the intestine and the kidney, where it facilitates sodium (re)absorption and proton secretion. The importance of NHE3 in the kidney for sodium chloride homeostasis, relative to the intestine, is unknown. Constitutive tubule-specific NHE3 knockout mice (NHE3 loxloxCre) did not show significant differences compared to control mice in body weight, blood pH or bicarbonate and plasma sodium, potassium, or aldosterone levels. Fluid intake, urinary flow rate, urinary sodium/creatinine, and pH were significantly elevated in NHE3 loxloxCre mice, while urine osmolality and GFR were significantly lower. Water deprivation revealed a small urinary concentrating defect in NHE3 loxloxCre mice on a control diet, exaggerated on low sodium chloride. Ten days of low or high sodium chloride diet did not affect plasma sodium in control mice; however, NHE3 loxloxCre mice were susceptible to low sodium chloride (about -4 mM) or high sodium chloride intake (about +2 mM) versus baseline, effects without differences in plasma aldosterone between groups. Blood pressure was significantly lower in NHE3 loxloxCre mice and was sodium chloride sensitive. In control mice, the expression of the sodium/phosphate co-transporter Npt2c was sodium chloride sensitive. However, lack of tubular NHE3 blunted Npt2c expression. Alterations in the abundances of sodium/chloride cotransporter and its phosphorylation at threonine 58 as well as the abundances of the α-subunit of the epithelial sodium channel, and its cleaved form, were also apparent in NHE3 loxloxCre mice. Thus, renal NHE3 is required to maintain blood pressure and steady-state plasma sodium levels when dietary sodium chloride intake is modified. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  5. Ablation of the Galnt3 gene leads to low-circulating intact fibroblast growth factor 23 (Fgf23) concentrations and hyperphosphatemia despite increased Fgf23 expression.

    Science.gov (United States)

    Ichikawa, Shoji; Sorenson, Andrea H; Austin, Anthony M; Mackenzie, Donald S; Fritz, Timothy A; Moh, Akira; Hui, Siu L; Econs, Michael J

    2009-06-01

    Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia. The disease is caused by inactivating mutations in fibroblast growth factor 23 (FGF23), Klotho (KL), and uridine diphosphate-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). In vitro studies indicate that GALNT3 O-glycosylates a phosphaturic hormone, FGF23, and prevents its proteolytic processing, thereby allowing secretion of intact FGF23. In this study we generated mice lacking the Galnt3 gene, which developed hyperphosphatemia without apparent calcifications. In response to hyperphosphatemia, Galnt3-deficient mice had markedly increased Fgf23 expression in bone. However, compared with wild-type and heterozygous littermates, homozygous mice had only about half of circulating intact Fgf23 levels and higher levels of C-terminal Fgf23 fragments in bone. Galnt3-deficient mice also exhibited an inappropriately normal 1,25-dihydroxyvitamin D level and decreased alkaline phosphatase activity. Furthermore, renal expression of sodium-phosphate cotransporters and Kl were elevated in Galnt3-deficient mice. Interestingly, there were sex-specific phenotypes; only Galnt3-deficient males showed growth retardation, infertility, and significantly increased bone mineral density. In summary, ablation of Galnt3 impaired secretion of intact Fgf23, leading to decreased circulating Fgf23 and hyperphosphatemia, despite increased Fgf23 expression. Our findings indicate that Galnt3-deficient mice have a biochemical phenotype of tumoral calcinosis and provide in vivo evidence that Galnt3 plays an essential role in proper secretion of Fgf23 in mice.

  6. Pulmonary alveolar microlithiasis

    International Nuclear Information System (INIS)

    Vallejo, Franco Javier; Vallejo, Alejandro; Parra, Maximiliano

    2007-01-01

    Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by the diffuse and bilateral presence of calcium phosphate microlite in the alveolar spaces. The progression of this potentially lethal disease is show and most of the patients remain asymptomatic during years or decades, resulting in a show deterioration of the pulmonary function. The typical finding of the sand storm in the chest X-ray is characteristic of this entity. Mutations in the SLC34A2 gene that does the coding for the type II co-transporter of sodium phosphate were identified as responsible for this disease. Of the almost 600 cases, only 6 have been reported in Colombia. We are presenting a case of pulmonary alveolar microlite in a 27 year old man, with progressive respiratory distress whose diagnosis was made by the X-ray findings and confirmed by trans bronchial biopsy. In the 2 years follow-up, shows evolution towards deterioration of his respiratory function making him a candidate for lung transplantation.

  7. Down-Regulation of the Na+-Coupled Phosphate Transporter NaPi-IIa by AMP-Activated Protein Kinase

    Directory of Open Access Journals (Sweden)

    Miribane Dërmaku-Sopjani

    2013-11-01

    Full Text Available Background/Aims: The Na+-coupled phosphate transporter NaPi-IIa is the main carrier accomplishing renal tubular phosphate reabsorption. It is driven by the electrochemical Na+ gradient across the apical cell membrane, which is maintained by Na+ extrusion across the basolateral cell membrane through the Na+/K+ ATPase. The operation of NaPi-IIa thus requires energy in order to avoid cellular Na+ accumulation and K+ loss with eventual decrease of cell membrane potential, Cl- entry and cell swelling. Upon energy depletion, early inhibition of Na+-coupled transport processes may delay cell swelling and thus foster cell survival. Energy depletion is sensed by the AMP-activated protein kinase (AMPK, a serine/threonine kinase stimulating several cellular mechanisms increasing energy production and limiting energy utilization. The present study explored whether AMPK influences the activity of NAPi-IIa. Methods: cRNA encoding NAPi-IIa was injected into Xenopus oocytes with or without additional expression of wild-type AMPK (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1-HA, of inactive AMPKαK45R (AMPKα1K45R+AMPKβ1-Flag+AMPKγ1-HA or of constitutively active AMPKγR70Q (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1R70Q. NaPi-IIa activity was estimated from phosphate-induced current in dual electrode voltage clamp experiments. Results: In NaPi-IIa-expressing, but not in water-injected Xenopus oocytes, the addition of phosphate (1 mM to the extracellular bath solution generated a current (Ip, which was significantly decreased by coexpression of wild-type AMPK and of AMPKγR70Q but not of AMPKαK45R. The phosphate-induced current in NaPi-IIa- and AMPK-expressing Xenopus ooocytes was significantly increased by AMPK inhibitor Compound C (20 µM. Kinetic analysis revealed that AMPK significantly decreased the maximal transport rate. Conclusion: The AMP-activated protein kinase AMPK is a powerful regulator of NaPi-IIa and thus of renal tubular phosphate transport.

  8. Passive water and urea permeability of a human Na(+)-glutamate cotransporter expressed in Xenopus oocytes

    DEFF Research Database (Denmark)

    Macaulay, Nanna; Gether, Ulrik; Klærke, Dan Arne

    2002-01-01

    to the K(0.5) value for glutamate activation of transport. The specific inhibitor DL-threo-beta-benzyloxyaspartate (TBOA) reduced the EAAT1-specific L(p) to 72 %. EAAT1 supported passive fluxes of [(14)C]urea and [(14)C]glycerol. The [(14)C]urea flux was increased in the presence of glutamate. The data...... suggest that the permeability depends on the conformational equilibrium of the EAAT1. At positive potentials and in the presence of Na(+) and glutamate, the pore is enlarged and water and urea penetrate more readily. The L(p) was larger when measured with urea or glycerol as osmolytes as compared...... with mannitol. Apparently, the properties of the pore are not uniform along its length. The outer section may accommodate urea and glycerol in an osmotically active form, giving rise to larger water fluxes. The physiological role of EAAT1 for water homeostasis in the central nervous system is discussed....

  9. Impact of sodium–glucose cotransporter 2 inhibitors on blood pressure

    Science.gov (United States)

    Reed, James W

    2016-01-01

    SGLT2 inhibitors are glucose-lowering agents used to treat type 2 diabetes mellitus (T2DM). These agents target the kidney to promote urinary glucose excretion, resulting in improved blood glucose control. SGLT2-inhibitor therapy is also associated with weight loss and blood pressure (BP) lowering. Hypertension is a common comorbidity in patients with T2DM, and is associated with excess morbidity and mortality. This review summarizes data on the effect of SGLT2 inhibitors marketed in the US (namely canagliflozin, dapagliflozin, or empagliflozin) on BP in patients with T2DM. Boolean searches were conducted that included terms related to BP or hypertension with terms for SGLT2 inhibitors, canagliflozin, dapagliflozin, or empagliflozin using PubMed, Google, and Google Scholar. Data from numerous randomized controlled trials of SGLT2 inhibitors in patients with T2DM demonstrated clinically relevant reductions in both systolic and diastolic BP, assessed via seated office measurements and 24-hour ambulatory BP monitoring. Observed BP lowering was not associated with compensatory increases in heart rate. Circadian BP rhythm was also maintained. The mechanism of SGLT2 inhibitor-associated BP reduction is not fully understood, but is assumed to be related to osmotic diuresis and natriuresis. Other factors that may also contribute to BP reduction include SGLT2 inhibitor-associated decreases in body weight and reduced arterial stiffness. Local inhibition of the renin–angiotensin–aldosterone system secondary to increased delivery of sodium to the juxtaglomerular apparatus during SGLT2 inhibition has also been postulated. Although SGLT2 inhibitors are not indicated as BP-lowering agents, the modest decreases in systolic and diastolic BP observed with SGLT2 inhibitors may provide an extra clinical advantage for the majority of patients with T2DM, in addition to improving blood glucose control. PMID:27822054

  10. MAP17 Is a Necessary Activator of Renal Na+/Glucose Cotransporter SGLT2

    Science.gov (United States)

    Coady, Michael J.; El Tarazi, Abdulah; Santer, René; Bissonnette, Pierre; Sasseville, Louis J.; Calado, Joaquim; Lussier, Yoann; Dumayne, Christopher; Bichet, Daniel G.

    2017-01-01

    The renal proximal tubule reabsorbs 90% of the filtered glucose load through the Na+-coupled glucose transporter SGLT2, and specific inhibitors of SGLT2 are now available to patients with diabetes to increase urinary glucose excretion. Using expression cloning, we identified an accessory protein, 17 kDa membrane-associated protein (MAP17), that increased SGLT2 activity in RNA-injected Xenopus oocytes by two orders of magnitude. Significant stimulation of SGLT2 activity also occurred in opossum kidney cells cotransfected with SGLT2 and MAP17. Notably, transfection with MAP17 did not change the quantity of SGLT2 protein at the cell surface in either cell type. To confirm the physiologic relevance of the MAP17–SGLT2 interaction, we studied a cohort of 60 individuals with familial renal glucosuria. One patient without any identifiable mutation in the SGLT2 coding gene (SLC5A2) displayed homozygosity for a splicing mutation (c.176+1G>A) in the MAP17 coding gene (PDZK1IP1). In the proximal tubule and in other tissues, MAP17 is known to interact with PDZK1, a scaffolding protein linked to other transporters, including Na+/H+ exchanger 3, and to signaling pathways, such as the A-kinase anchor protein 2/protein kinase A pathway. Thus, these results provide the basis for a more thorough characterization of SGLT2 which would include the possible effects of its inhibition on colocalized renal transporters. PMID:27288013

  11. Alternative splice variant of the thiazide-sensitive NaCl cotransporter

    DEFF Research Database (Denmark)

    Tutakhel, Omar A Z; Jeleń, Sabina; Valdez-Flores, Marco

    2016-01-01

    in comparison to NCC3. Mimicking a constitutively active phosphorylation site at residue 811 (S811D) in NCC1 further augmented Na(+) transport, while a non-phosphorylatable variant (S811A) of NCC1 prevented this enhanced response. Analysis of human urinary exosomes demonstrated that water loading in human...

  12. Investigations into co-transport phenomena in PUREX relevant solutions by use of an analytical ultracentrifuge

    International Nuclear Information System (INIS)

    Gauglitz, R.; Marx, G.

    1991-01-01

    The diffusion of the elements uranium, neodymium, chromium, iron, ruthenium was studied in aqueous and aqueous nitric acid solutions. The diffusion of these elements was measured not only under a concentration gradient but also with respect to simultanious nitric and diffusion. Measurements with schlierenoptics and with uv/vis.-optic were carried out at the same time. Besides the diffusion of metal nitrates and potassium dichromate also nitric acid diffusion was investigated. Also in this case apparent diffusion coefficients were determined under concentration gradients and under the influence of superposing element gradients. The diffusion of the elements uranium, neodymium, ruthenium, neptunium and plutonium was also determined in organic systems. At first the transport of the elements was measured under an element gradient, in presence of various amounts of water and nitric acid. These experiments were followed by those on simultanious diffusion of water of nitric acid and elements in TBP/dodecane mixture. Furthermore TBP/dodecane solutions were oxidized with potassium dichromate. This oxidation was measured using a gaschromatograph. From the obtained results the formation rate for the oxidation products could be calculated which proved that higher nitric acid concentrations increased the rate. (orig.) With 16 refs., 100 tabs., 120 figs [de

  13. Approaching to DM2 through sodium-glucose cotransporter-2: does it make sense?

    Science.gov (United States)

    Segura, Julián

    2016-11-01

    The kidney is involved in glucose homeostasis through three main mechanisms: renal gluconeogenesis, renal glucose consumption and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most relevant physiological functions of the kidney, through which filtered glucose is fully recovered, urine is free of glucose, and calorie loss is prevented. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where GLUT2 and SGLT2 transporters are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycaemia, the kidney continues reabsorbing glucose, and hyperglycaemia is maintained. Most renal glucose reabsorption is mediated by the SGLT2 transporter. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  14. Conformational Dynamics of hSGLT1 during Na+/Glucose Cotransport

    DEFF Research Database (Denmark)

    Loo, D. D.; Hirayama, B. A.; Karakossian, M. H.

    2006-01-01

    at the expense of outward-facing conformations. The simulations predict, and we have observed experimentally, that presteady-state currents are blocked by saturating sugar, but not the changes in fluorescence. Thus we have isolated an electroneutral conformational change that has not been previously described......) was totally abolished, whereas Fmax was only reduced 50%. Phlorizin reduced both Qmax and Fmax (Ki 0.4 µM), with no changes in V0.5's or relaxation time constants. Simulations using an eight-state kinetic model indicate that external sugar increases the occupancy probability of inward-facing conformations...

  15. 4-acetoxyscirpendiol of Paecilomyces tenuipes inhibits Na(+)/D-glucose cotransporter expressed in Xenopus laevis oocytes.

    Science.gov (United States)

    Yoo, Ocki; Son, Joo-Hiuk; Lee, Dong-Hee

    2005-03-31

    Cordyceps, an entomopathogenic fungus, contains many health-promoting ingredients. Recent reports indicate that the consumption of cordyceps helps reduce blood-sugar content in diabetics. However, the mechanism underlying this reduction in circulatory sugar content is not fully understood. Methanolic extracts were prepared from the fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (4-ASD) was eventually isolated and purified. Na(+)/Glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of 4-ASD on SGLT-1 was analyzed utilizing a voltage clamp and by performing 2-deoxy-D-glucose (2-DOG) uptake studies. 4-ASD was shown to significantly inhibit SGLT-1 activity compared to the non-treated control in a dose-dependent manner. In the presence of the derivatives of 4-ASD (diacetoxyscirpenol or 15-acetoxyscirpendiol), SGLT-1 activity was greatly inhibited in an 4-ASD-like manner. Of these derivatives, 15-acetoxyscirepenol inhibited SGLT-1 as well as 4-ASD, whereas diacetoxyscirpenol was slightly less effective. Taken together, these results strongly indicate that 4-ASD in P. tenuipes may lower blood sugar levels in the circulatory system. We conclude that 4-ASD and its derivatives are effective SGLT-1 inhibitors.

  16. Hemodynamic and renal implications of sodium-glucose cotransporter- 2 inhibitors in type 2 diabetes mellitus.

    Science.gov (United States)

    Tejedor Jorge, Alberto

    2016-11-01

    In DM2, there is increased expression of the proximal glucose transporter SGLT2. The increased glucose reabsorption from the urine to the proximal tubule and subsequently to the bloodstream, has three direct effects on the prognosis of patients with DM2: a) it increases the daily glucose load by raising the renal threshold for glucose, thus augmenting requirements for oral antidiabetics and insulin. This progressive increase occurs throughout the course of the disease and in parallel with the increase in renal mass (renal hypertrophy); b) because of the greater glucose reabsorption, glycosuria is lower than the level corresponding to glycaemia, decreasing the stimulus on the tubuloglomerular feedback system of the distal nephron. As a result, the glomerular vasodilation caused by hyperglycaemia is not arrested, maintaining glomerular hyperfiltration, and c) the excess glucose transported to the proximal tubular cells modifies their redox status, increasing local production of glycosylating products and activating local production of proinflammatory and profibrotic proliferative mediators. These mediators are responsible for the direct free radical damage to proximal tubular cells, for increased SGLT2 expression, increased production of collagen IV and extracellular matrix, and activation of monocyte/macrophages able to cause endothelial injury. The use of SGLT2 inhibitors not only reduces the reabsorption of glucose from the glomerular filtrate back into the circulationthus improving metabolic control in diabetesbut also restores tubuloglomerular feedback by increasing glycosuria and distal urinary flow. However, the most notable effect is due to inhibition of glucose entry to the proximal tubular cells. Glycosuria is toxic to the kidney: it harms glucosetransporting cells, that is, the proximal cells, which contain SGLT2. In animal models, SGLT2 inhibition reduces local production of oxygen-free radicals, the formation of mesangial matrix and collagen IV, glomerular infiltration by inflammatory cells and monocyte/macrophage-dependent arteriosclerosis. In humans, SGLT2 have a demonstrated ability to reduce renal injury and cardiovascular risk in patients with type 2 diabetes mellitus. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  17. The plant homolog to the human sodium/dicarboxylic cotransporter is the vacuolar malate carrier

    OpenAIRE

    Emmerlich, Vera; Linka, Nicole; Reinhold, Thomas; Hurth, Marco A.; Traub, Michaela; Martinoia, Enrico; Neuhaus, H. Ekkehard

    2003-01-01

    Malate plays a central role in plant metabolism. It is an intermediate in the Krebs and glyoxylate cycles, it is the store for CO2 in C4 and crassulacean acid metabolism plants, it protects plants from aluminum toxicity, it is essential for maintaining the osmotic pressure and charge balance, and it is therefore involved in regulation of stomatal aperture. To fulfil many of these roles, malate has to be accumulated within the large central vacuole. Many unsuccessful efforts have been made in ...

  18. The choroid plexus sodium-bicarbonate cotransporter NBCe2 regulates cerebrospinal fluid pH

    DEFF Research Database (Denmark)

    Barbuskaite, Dagne; Praetorius, Jeppe; Christensen, Henriette L.

    2017-01-01

    Respiratory centers in the central nervous system (CNS) react to changes in pCO2 and maintain systemic acid/base homeostasis by controlling the rate and depth of respiration. Both blood-brain barrier and blood-CSF barrier are highly permeable to CO2 enabling swift transmission of arterial pCO2 fl...

  19. Intronic deletions in the SLC34A3 gene: A cautionary tale for mutation analysis of hereditary hypophosphatemic rickets with hypercalciuria

    Science.gov (United States)

    Ichikawa, Shoji; Tuchman, Shamir; Padgett, Leah R.; Gray, Amie K.; Baluarte, H. Jorge; Econs, Michael J.

    2013-01-01

    Hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is a rare metabolic disorder, characterized by hypophosphatemia, variable degrees of rickets/osteomalacia, and hypercalciuria secondary to increased serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels. HHRH is caused by mutations in the SLC34A3 gene, which encodes sodium-phosphate co-transporter type IIc. A 6 ½-year-old female presented with a history of nephrolithiasis. Her metabolic evaluation revealed increased 24- hour urine calcium excretion with high serum calcium, low intact parathyroid hormone (PTH) levels, and elevated 1,25(OH)2D level. In addition, the patient had low to low-normal serum phosphorus with high urine phosphorus. The patient had normal stature; without rachitic or boney deformities or a history of fractures. Genetic analysis of SLC34A3 revealed the patient to be a compound heterozygote for a novel single base pair deletion in exon 12 (c.1304delG) and 30-base pair deletion in intron 6 (g.1440–1469del). The single-base pair mutation causes a frameshift, which results in premature stop codon. The intronic deletion is likely caused by misalignment of the 4-basepair homologous repeats and results in the truncation of an already small intron to 63 bp, which would impair proper RNA splicing of the intron. This is the fourth unique intronic deletion identified in patients with HHRH, suggesting the frequent occurrence of sequence misalignments in SLC34A3 and the importance of screening introns in patients with HHRH. PMID:24176905

  20. Physiological Actions of Fibroblast Growth Factor-23

    Directory of Open Access Journals (Sweden)

    Reinhold G. Erben

    2018-05-01

    Full Text Available Fibroblast growth factor-23 (FGF23 is a bone-derived hormone suppressing phosphate reabsorption and vitamin D hormone synthesis in the kidney. At physiological concentrations of the hormone, the endocrine actions of FGF23 in the kidney are αKlotho-dependent, because high-affinity binding of FGF23 to FGF receptors requires the presence of the co-receptor αKlotho on target cells. It is well established that excessive concentrations of intact FGF23 in the blood lead to phosphate wasting in patients with normal kidney function. Based on the importance of diseases associated with gain of FGF23 function such as phosphate-wasting diseases and chronic kidney disease, a large body of literature has focused on the pathophysiological consequences of FGF23 excess. Less emphasis has been put on the role of FGF23 in normal physiology. Nevertheless, during recent years, lessons we have learned from loss-of-function models have shown that besides the paramount physiological roles of FGF23 in the control of 1α-hydroxylase expression and of apical membrane expression of sodium-phosphate co-transporters in proximal renal tubules, FGF23 also is an important stimulator of calcium and sodium reabsorption in distal renal tubules. In addition, there is an emerging role of FGF23 as an auto-/paracrine regulator of alkaline phosphatase expression and mineralization in bone. In contrast to the renal actions of FGF23, the FGF23-mediated suppression of alkaline phosphatase in bone is αKlotho-independent. Moreover, FGF23 may be a physiological suppressor of differentiation of hematopoietic stem cells into the erythroid lineage in the bone microenvironment. At present, there is little evidence for a physiological role of FGF23 in organs other than kidney and bone. The purpose of this mini-review is to highlight the current knowledge about the complex physiological functions of FGF23.

  1. Metallothionein deficiency aggravates depleted uranium-induced nephrotoxicity

    International Nuclear Information System (INIS)

    Hao, Yuhui; Huang, Jiawei; Gu, Ying; Liu, Cong; Li, Hong; Liu, Jing; Ren, Jiong; Yang, Zhangyou; Peng, Shuangqing; Wang, Weidong; Li, Rong

    2015-01-01

    Depleted uranium (DU) has been widely used in both civilian and military activities, and the kidney is the main target organ of DU during acute high-dose exposures. In this study, the nephrotoxicity caused by DU in metallothionein-1/2-null mice (MT −/−) and corresponding wild-type (MT +/+) mice was investigated to determine any associations with MT. Each MT −/− or MT +/+ mouse was pretreated with a single dose of DU (10 mg/kg, intraperitoneal injection) or an equivalent volume of saline. After 4 days of DU administration, kidney changes were assessed. After DU exposure, serum creatinine and serum urea nitrogen in MT −/− mice significantly increased than in MT +/+ mice, with more severe kidney pathological damage. Moreover, catalase and superoxide dismutase (SOD) decreased, and generation of reactive oxygen species and malondialdehyde increased in MT −/− mice. The apoptosis rate in MT −/− mice significantly increased, with a significant increase in both Bax and caspase 3 and a decrease in Bcl-2. Furthermore, sodium-glucose cotransporter (SGLT) and sodium-phosphate cotransporter (NaPi-II) were significantly reduced after DU exposure, and the change of SGLT was more evident in MT −/− mice. Finally, exogenous MT was used to evaluate the correlation between kidney changes induced by DU and MT doses in MT −/− mice. The results showed that, the pathological damage and cell apoptosis decreased, and SOD and SGLT levels increased with increasing dose of MT. In conclusion, MT deficiency aggravated DU-induced nephrotoxicity, and the molecular mechanisms appeared to be related to the increased oxidative stress and apoptosis, and decreased SGLT expression. - Highlights: • MT −/− and MT +/+ mice were used to evaluate nephrotoxicity of DU. • Renal damage was more evident in the MT −/− mice after exposure to DU. • Exogenous MT also protects against DU-induced nephrotoxicity. • MT deficiency induced more ROS and apoptosis after exposure to

  2. Metallothionein deficiency aggravates depleted uranium-induced nephrotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Yuhui; Huang, Jiawei; Gu, Ying; Liu, Cong; Li, Hong; Liu, Jing; Ren, Jiong; Yang, Zhangyou [State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, No. 30 Gaotanyan Street, Shapingba District, Chongqing 400038 (China); Peng, Shuangqing [Evaluation and Research Center for Toxicology, Institute of Disease Control and Prevention, Academy of Military Medical Science, 20 Dongdajie Street, Fengtai District, Beijing 100071 (China); Wang, Weidong, E-mail: wwdwyl@sina.com [Department of Radiation Oncology, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Shanghai 200233 (China); Li, Rong, E-mail: yuhui_hao@126.com [State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, No. 30 Gaotanyan Street, Shapingba District, Chongqing 400038 (China)

    2015-09-15

    Depleted uranium (DU) has been widely used in both civilian and military activities, and the kidney is the main target organ of DU during acute high-dose exposures. In this study, the nephrotoxicity caused by DU in metallothionein-1/2-null mice (MT −/−) and corresponding wild-type (MT +/+) mice was investigated to determine any associations with MT. Each MT −/− or MT +/+ mouse was pretreated with a single dose of DU (10 mg/kg, intraperitoneal injection) or an equivalent volume of saline. After 4 days of DU administration, kidney changes were assessed. After DU exposure, serum creatinine and serum urea nitrogen in MT −/− mice significantly increased than in MT +/+ mice, with more severe kidney pathological damage. Moreover, catalase and superoxide dismutase (SOD) decreased, and generation of reactive oxygen species and malondialdehyde increased in MT −/− mice. The apoptosis rate in MT −/− mice significantly increased, with a significant increase in both Bax and caspase 3 and a decrease in Bcl-2. Furthermore, sodium-glucose cotransporter (SGLT) and sodium-phosphate cotransporter (NaPi-II) were significantly reduced after DU exposure, and the change of SGLT was more evident in MT −/− mice. Finally, exogenous MT was used to evaluate the correlation between kidney changes induced by DU and MT doses in MT −/− mice. The results showed that, the pathological damage and cell apoptosis decreased, and SOD and SGLT levels increased with increasing dose of MT. In conclusion, MT deficiency aggravated DU-induced nephrotoxicity, and the molecular mechanisms appeared to be related to the increased oxidative stress and apoptosis, and decreased SGLT expression. - Highlights: • MT −/− and MT +/+ mice were used to evaluate nephrotoxicity of DU. • Renal damage was more evident in the MT −/− mice after exposure to DU. • Exogenous MT also protects against DU-induced nephrotoxicity. • MT deficiency induced more ROS and apoptosis after exposure to

  3. Human NKCC2 cation–Cl– co-transporter complements lack of Vhc1 transporter in yeast vacuolar membranes

    Czech Academy of Sciences Publication Activity Database

    Petrezsélyová, Silvia; Domínguez, A.; Herynková, Pavla; Macias, J. F.; Sychrová, Hana

    2013-01-01

    Roč. 30, č. 10 (2013), s. 395-402 ISSN 0749-503X R&D Projects: GA MŠk(CZ) LC531; GA AV ČR(CZ) IAA500110801 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200110901 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : heterologous expression * CCC family * alkali-metal-cation tolerance * Saccharomyces cerevisiae * ion homeostasis Subject RIV: EE - Microbiology, Virology Impact factor: 1.742, year: 2013

  4. Cotransport of microorganisms and metallic colloids in quartz sand or iron oxide-coated sand under real site hydrogeological conditions

    Science.gov (United States)

    Yu, Tong; Wen, Yujuan; Yang, Xinyao; Yang, Yuesuo

    2017-04-01

    The need for studying the fate and transport of engineered and naturally-occurring nanoparticles is of great concern in the past decade. Wudalianchi scenic spot as a famous International Geological Park has the biggest cold spring in China, which is also one of the three biggest cold spring in the world, with a history of over 200 years using in drinking and medical purpose. Thousands of tourists all over the world travelling here each year to enjoy the high quality mineral water and take a bath in the cold spring and "mud-bath" with special medication purposes. Recreation activities gave rise to the engineered nanomaterials (ENMs) releasing into the water environment and increase the risk of contamination. Therefore, it is necessary to evaluate the effect of ENMs-exposure in natural environment and how it influences the transport of microorganisms of Wudalianchi in/without the presence of natural colloids (humic acid) under a series of ion strength. A thorough critical literature review of both work in the study site and the bio/nano-particle transport in porous media was a kick-off of the study. With support of the site investigations and sampling of groundwater, surface water and surface mud/soils, further numerical modelling of the hydrogeochemical speciation of the groundwater was carried out, indicating comprehensive water-rock interactions of this particular region. Metallic nanoparticles (MNPs), including metals, metal oxides and other metal-containing nanoparticles, are produced and ubiquitously applied to medical, cosmetic, photonics and catalysis industries, etc. TiO2, a widely used raw material for cosmetic industries (e.g., sunscreens), was used in this study to represent MNPs. The microorganisms used in this study were extracted from the soil in Wudalianchi. Humic acid (HA), a key component of dissolved organic matter (DOM) chosen as the natural colloids in this study, are ubiquitous and significant constituents in soils and water environment that plays an important part in many soil and water processes. The column experiments were carried out using homogeneously charged (quartz sand) and heterogeneously charged (iron oxide-coated sand) porous media. References: Yang, X., Zhang, Y., Chen, F., & Yang, Y. (2015). Interplay of natural organic matter with flow rate and particle size on colloid transport: Experimentation, visualization, and modeling. Environmental science & technology, 49(22), 13385-13393. Yang, X., Yin, Z., Chen, F., Hu, J., & Yang, Y. (2015). Organic matter induced mobilization of polymer-coated silver nanoparticles from water-saturated sand. Science of the Total Environment, 529, 182-190. Wen, Y. J., Yang, Y. S., Ren, H. J., Du, X. Q., Yang, X. Y., Zhang, L. Y., & Wang, X. S. (2015). Chemical-biological hybrid reactive zones and their impact on biodiversity of remediation of the nitrobenzene and aniline contaminated groundwater. Chemical Engineering Journal, 280, 233-240.

  5. The Na+-D-glucose cotransporters SGLT1 and SGLT2 are targets for the treatment of diabetes and cancer.

    Science.gov (United States)

    Koepsell, Hermann

    2017-02-01

    Orally applied SGLT2 (SLC5A2) inhibitors that enter the blood and decrease renal reabsorption of glucose have been approved as antidiabetic drugs. They decrease blood glucose levels, slightly reduce body weight and blood pressure, and decrease the risk for diabetic nephropathy. The SGLT2 inhibitor empagliflozin has been shown to reduce the risk of severe cardiac failure. This review summarizes knowledge about the functions of SGLT2 and the pathophysiology of type 2 diabetes (T2D) and diabetic follow-up diseases. In addition, proposed pathophysiological mechanisms of therapeutic effects and of side effects of SGLT2 inhibitors are described. A recently investigated strategy to employ orally applied SGLT1 (SLC5A1) inhibitors for treatment of diabetes is discussed. The SGLT1 inhibitors reduce glucose absorption and decrease blood glucose excursions after the intake of glucose-rich food. Knowledge concerning the expression of SGLT1 in different organs is compiled and potential side effects of SGLT1 inhibitors entering the blood are discussed. Because selective targeting of SGLT1 expression presents a strategy to decrease SGLT1-mediated glucose absorption, current knowledge about the regulation of SGLT1 is also discussed. This includes the possibility to decrease SGLT1 abundance in the small intestinal brush-border membrane by a peptide derived from protein RS1 (RSC1A1) that regulates membrane trafficking. Finally the possibility to employ SGLT1 and SGLT2 as targets for anticancer therapy is discussed. SGLT1 and SGLT2 are expressed in various tumors where they supply the tumor cells with glucose for euglycemic glycolysis. Tumor growth of carcinoma expressing SGLT2 can be slowed down by an SGLT2 inhibitor. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Co-transport of chlordecone and sulfadiazine in the presence of functionalized multi-walled carbon nanotubes in soils

    Science.gov (United States)

    Batch and saturated soil column experiments were conducted to investigate sorption and mobility of two 14C-labeled contaminants, the hydrophobic chlordecone (CLD) and the readily water-soluble sulfadiazine (SDZ), in the absence or presence of functionalized multi-walled carbon nanotubes (MWCNTs). Th...

  7. Co-Transport of Polycyclic Aromatic Hydrocarbons by Motile Microorganisms Leads to Enhanced Mass Transfer under Diffusive Conditions

    DEFF Research Database (Denmark)

    Gilbert, Dorthea; Jakobsen, Hans H.; Winding, Anne

    2014-01-01

    as sink and source for polycyclic aromatic hydrocarbons (PAHs). This resulted in stable concentration gradients in water (>24 h). Adding the model organism Tetrahymena pyriformis to the experimental system enhanced PAH mass transfer up to hundred-fold (benzo[a]pyrene). Increasing mass transfer enhancement...

  8. A minor role of WNK3 in regulating phosphorylation of renal NKCC2 and NCC co-transporters in vivo

    Directory of Open Access Journals (Sweden)

    Katsuyuki Oi

    2012-02-01

    Mutations in WNK1 and WNK4 kinase genes have been shown to cause a human hereditary hypertensive disease, pseudohypoaldosteronism type II (PHAII. We previously discovered that WNK kinases phosphorylate and activate OSR1/SPAK kinases that regulate renal SLC12A family transporters such as NKCC2 and NCC, and clarified that the constitutive activation of this cascade causes PHAII. WNK3, another member of the WNK kinase family, was reported to be a strong activator of NCC/NKCC2 when assayed in Xenopus oocytes, suggesting that WNK3 also plays a major role in regulating blood pressure and sodium reabsorption in the kidney. However, it remains to be determined whether WNK3 is in fact involved in the regulation of these transporters in vivo. To clarify this issue, we generated and analyzed WNK3 knockout mice. Surprisingly, phosphorylation and expression of OSR1, SPAK, NKCC2 and NCC did not decrease in knockout mouse kidney under normal and low-salt diets. Similarly, expression of epithelial Na channel and Na/H exchanger 3 were not affected in knockout mice. Na+ and K+ excretion in urine in WNK3 knockout mice was not affected under different salt diets. Blood pressure in WNK3 knockout mice was not lower under normal diet. However, lower blood pressure was observed in WNK3 knockout mice fed low-salt diet. WNK4 and WNK1 expression was slightly elevated in the knockout mice under low-salt diet, suggesting compensation for WNK3 knockout by these WNKs. Thus, WNK3 may have some role in the WNK-OSR1/SPAK-NCC/NKCC2 signal cascade in the kidney, but its contribution to total WNK kinase activity may be minimal.

  9. Ablation of Potassium-Chloride Cotransporter Type 3 (Kcc3) in Mouse Causes Multiple Cardiovascular Defects and Isosmotic Polyuria.

    Science.gov (United States)

    Garneau, Alexandre P; Marcoux, Andrée-Anne; Noël, Micheline; Frenette-Cotton, Rachelle; Drolet, Marie-Claude; Couet, Jacques; Larivière, Richard; Isenring, Paul

    2016-01-01

    Inactivation of Kcc3 in a mixed 129/Sv×C57BL/6 mouse background has been previously found to increase systemic blood pressure (BP) through presumed neurogenic mechanisms. Yet, while this background is generally not considered ideal to investigate the cardiovascular system, KCC3 is also expressed in the arterial wall and proximal nephron. In the current study, the effects of Kcc3 ablation was investigated in a pure rather than mixed C57BL/6J background under regular- and high-salt diets to determine whether they could be mediated through vasculogenic and nephrogenic mechanisms. Aortas were also assessed for reactivity to pharmacological agents while isolated from the influence of sympathetic ganglia. This approach led to the identification of unforeseen abnormalities such as lower pulse pressure, heart rate, aortic reactivity and aortic wall thickness, but higher diastolic BP, left ventricular mass and urinary output in the absence of increased catecholamine levels. Salt loading also led systolic BP to be higher, but to no further changes in hemodynamic parameters. Importantly, aortic vascular smooth muscle cells and cardiomyocytes were both found to express KCC3 abundantly in heterozygous mice. Hence, Kcc3 inactivation in our model caused systemic vascular resistance and ventricular mass to increase while preventing extracellular fluid volume to accumulate. Given that it also affected the physiological properties of aortas in vitro, vasculogenic mechanisms could therefore account for a number of the hemodynamic abnormalities observed.

  10. Impaired nutrient signaling and body weight control in a Na+ neutral amino acid cotransporter (Slc6a19)-deficient mouse.

    Science.gov (United States)

    Bröer, Angelika; Juelich, Torsten; Vanslambrouck, Jessica M; Tietze, Nadine; Solomon, Peter S; Holst, Jeff; Bailey, Charles G; Rasko, John E J; Bröer, Stefan

    2011-07-29

    Amino acid uptake in the intestine and kidney is mediated by a variety of amino acid transporters. To understand the role of epithelial neutral amino acid uptake in whole body homeostasis, we analyzed mice lacking the apical broad-spectrum neutral (0) amino acid transporter B(0)AT1 (Slc6a19). A general neutral aminoaciduria was observed similar to human Hartnup disorder which is caused by mutations in SLC6A19. Na(+)-dependent uptake of neutral amino acids into the intestine and renal brush-border membrane vesicles was abolished. No compensatory increase of peptide transport or other neutral amino acid transporters was detected. Mice lacking B(0)AT1 showed a reduced body weight. When adapted to a standard 20% protein diet, B(0)AT1-deficient mice lost body weight rapidly on diets containing 6 or 40% protein. Secretion of insulin in response to food ingestion after fasting was blunted. In the intestine, amino acid signaling to the mammalian target of rapamycin (mTOR) pathway was reduced, whereas the GCN2/ATF4 stress response pathway was activated, indicating amino acid deprivation in epithelial cells. The results demonstrate that epithelial amino acid uptake is essential for optimal growth and body weight regulation.

  11. Gram-scale solution-phase synthesis of selective sodium bicarbonate Co-transport Inhibitor S0859

    DEFF Research Database (Denmark)

    Larsen, Ann Møller; Krogsgaard-Larsen, Niels; Lauritzen, Gitte

    2012-01-01

    Na+-coupled HCO3- transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast...

  12. Characterization of particle deformation during compression measured by confocal laser scanning microscopy.

    Science.gov (United States)

    Guo, H X; Heinämäki, J; Yliruusi, J

    1999-09-20

    Direct compression of riboflavin sodium phosphate tablets was studied by confocal laser scanning microscopy (CLSM). The technique is non-invasive and generates three-dimensional (3D) images. Tablets of 1% riboflavin sodium phosphate with two grades of microcrystalline cellulose (MCC) were individually compressed at compression forces of 1.0 and 26.8 kN. The behaviour and deformation of drug particles on the upper and lower surfaces of the tablets were studied under compression forces. Even at the lower compression force, distinct recrystallized areas in the riboflavin sodium phosphate particles were observed in both Avicel PH-101 and Avicel PH-102 tablets. At the higher compression force, the recrystallization of riboflavin sodium phosphate was more extensive on the upper surface of the Avicel PH-102 tablet than the Avicel PH-101 tablet. The plastic deformation properties of both MCC grades reduced the fragmentation of riboflavin sodium phosphate particles. When compressed with MCC, riboflavin sodium phosphate behaved as a plastic material. The riboflavin sodium phosphate particles were more tightly bound on the upper surface of the tablet than on the lower surface, and this could also be clearly distinguished by CLSM. Drug deformation could not be visualized by other techniques. Confocal laser scanning microscopy provides valuable information on the internal mechanisms of direct compression of tablets.

  13. Physiologic effects of bowel preparation

    DEFF Research Database (Denmark)

    Holte, Kathrine; Nielsen, Kristine Grubbe; Madsen, Jan Lysgård

    2004-01-01

    healthy volunteers (median age, 63 years) underwent bowel preparation with bisacodyl and sodium phosphate. Fluid and food intake were standardized according to weight, providing adequate calorie and oral fluid intake. Before and after bowel preparation, weight, exercise capacity, orthostatic tolerance...

  14. Induction of Pro-Angiogenic Factors by Pregnancy-Specific Glycoproteins and Studies on Receptor Usage

    Science.gov (United States)

    2008-01-01

    induce pro- angiogenic factors during pregancy . To address this, the specific aims of this study are to: 1. Examine the cytokine expression of monocytes...dialyzed into a 20 mM sodium phosphate...it was processed as described below. 68 PSG1d-Flag and PSG22N1A were dialyzed into a 20 mM sodium phosphate buffer containing 20 mM imidazole

  15. Adsorption characteristics of activated carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    B. V. Kaludjerović

    2009-01-01

    Full Text Available Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  16. Determination of monosaccharides derivatized with 2-aminobenzoic Acid by capillary electrophoresis.

    Science.gov (United States)

    Abo, Mitsuru; He, Li-Ping; Sato, Kae; Okubo, Akira

    2013-01-01

    Reducing monosaccharides were derivatized with 2-aminobenzoic acid (2-AA) through reductive amination using sodium cyanoborohydride as a reductant, and the derivatives were separated by capillary zone electrophoresis with UV detection using 50 mM sodium phosphate (pH 5.5) or 150 mM sodium borate-50 mM sodium phosphate (pH 7.0) running buffer. The derivatives of monosaccharides, which are major components of various carbohydrate materials, were completely separated within 25 min.

  17. Dysregulated gene expression in the primary osteoblasts and osteocytes isolated from hypophosphatemic Hyp mice.

    Directory of Open Access Journals (Sweden)

    Kazuaki Miyagawa

    Full Text Available Osteocytes express multiple genes involved in mineral metabolism including PHEX, FGF23, DMP1 and FAM20C. In Hyp mice, a murine model for X-linked hypophosphatemia (XLH, Phex deficiency results in the overproduction of FGF23 in osteocytes, which leads to hypophosphatemia and impaired vitamin D metabolism. In this study, to further clarify the abnormality in osteocytes of Hyp mice, we obtained detailed gene expression profiles in osteoblasts and osteocytes isolated from the long bones of 20-week-old Hyp mice and wild-type (WT control mice. The expression of Fgf23, Dmp1, and Fam20c was higher in osteocytic cells than in osteoblastic cells in both genotypes, and was up-regulated in Hyp cells. Interestingly, the up-regulation of these genes in Hyp bones began before birth. On the other hand, the expression of Slc20a1 encoding the sodium/phosphate (Na+/Pi co-transporter Pit1 was increased in osteoblasts and osteocytes from adult Hyp mice, but not in Hyp fetal bones. The direct effects of extracellular Pi and 1,25-dihydroxyvitamin D3 [1,25(OH2D3] on isolated osteoblastic and osteocytic cells were also investigated. Twenty-four-hour treatment with 10-8 M 1,25(OH2D3 increased the expression of Fgf23 in WT osteoblastic cells but not in osteocytic cells. Dmp1 expression in osteocytic cells was increased due to the 24-hour treatment with 10 mM Pi and was suppressed by 10-8 M 1,25(OH2D3 in WT osteocytic cells. We also found the up-regulation of the genes for FGF1, FGF2, their receptors, and Egr-1 which is a target of FGF signaling, in Hyp osteocytic cells, suggesting the activation of FGF/FGFR signaling. These results implicate the complex gene dysregulation in osteoblasts and osteocytes of Hyp mice, which might contribute to the pathogenesis.

  18. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    Directory of Open Access Journals (Sweden)

    Manoocher Soleimani

    Full Text Available Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2 and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2 in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of

  19. Lower risk of heart failure and death in patients initiated on sodium-glucose cotransporter-2 inhibitors versus other glucose-lowering drugs

    DEFF Research Database (Denmark)

    Kosiborod, Mikhail; Cavender, Matthew A.; Fu, Alex Z.

    2017-01-01

    and death in patients newly initiated on any SGLT-2i versus other glucose-lowering drugs in 6 countries to determine if these benefits are seen in real-world practice and across SGLT-2i class. METHODS: Data were collected via medical claims, primary care/hospital records, and national registries from...... for Germany. RESULTS: After propensity matching, there were 309 056 patients newly initiated on either SGLT-2i or other glucose-lowering drugs (154 528 patients in each treatment group). Canagliflozin, dapagliflozin, and empagliflozin accounted for 53%, 42%, and 5% of the total exposure time in the SGLT-2i...... class, respectively. Baseline characteristics were balanced between the 2 groups. There were 961 HHF cases during 190 164 person-years follow-up (incidence rate, 0.51/100 person-years). Of 215 622 patients in the United States, Norway, Denmark, Sweden, and the United Kingdom, death occurred in 1334...

  20. Gram-scale solution-phase synthesis of selective sodium bicarbonate co-transport inhibitor S0859: in vitro efficacy studies in breast cancer cells.

    Science.gov (United States)

    Larsen, Ann M; Krogsgaard-Larsen, Niels; Lauritzen, Gitte; Olesen, Christina W; Honoré Hansen, Steen; Boedtkjer, Ebbe; Pedersen, Stine F; Bunch, Lennart

    2012-10-01

    Na(+)-coupled HCO(3)(-) transporters (NBCs) mediate the transport of bicarbonate ions across cell membranes and are thus ubiquitous regulators of intracellular pH. NBC dysregulation is associated with a range of diseases; for instance, NBCn1 is strongly up-regulated in a model of ErbB2-dependent breast cancer, a malignant and widespread cancer with no targeted treatment options, and single-nucleotide polymorphisms in NBCn1 genetically link to breast cancer development and hypertension. The N-cyanosulfonamide S0859 has been shown to selectively inhibit NBCs, and its availability on the gram scale is therefore of significant interest to the scientific community. Herein we describe a short and efficient synthesis of S0859 with an overall yield of 45 % from commercially available starting materials. The inhibitory effect of S0859 on recovery of intracellular pH after an acid load was verified in human and murine cancer cell lines in Ringer solutions. However, S0859 binds very strongly to components in plasma, and accordingly, measurements on isolated murine tissues showed no effect of S0859 at concentrations up to 50 μM. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Na+,HCO3--cotransport is functionally upregulated during human breast carcinogenesis and required for the inverted pH gradient across the plasma membrane

    DEFF Research Database (Denmark)

    Lee, Soojung; Mele, Marco; Vahl, Pernille

    2015-01-01

    Metabolic and biochemical changes during breast carcinogenesis enhance cellular acid production. Extrusion of the acid load from the cancer cells raises intracellular pH, while it decreases extracellular pH creating an inverted pH gradient across the plasma membrane compared to normal cells and p...

  2. Protective effects of Cassia tora leaves in experimental cataract by modulating intracellular communication, membrane co-transporters, energy metabolism and the ubiquitin-proteasome pathway.

    Science.gov (United States)

    Sreelakshmi, V; Abraham, Annie

    2017-12-01

    Cataract is the clouding of eye lens which causes impairment in vision and accounts for the leading factor of global blindness. Functional food-based prevention of cataract finds application in vision research because of its availability and easy access to all classes of the society. Cassia tora Linn. (Caesalpinaceae) is an edible plant mentioned in the traditional systems of medicine for whole body health, especially to the eyes. The present study evaluates the potential of ethyl acetate fraction of Cassia tora leaves (ECT) on experimental cataract. Cataract was induced by a single subcutaneous injection of sodium selenite (4 μg/g body weight) on 10th day. ECT was supplemented orally from 8th day up to 12th day at a concentration of 5 μg/g body weight and marker parameters were evaluated after 30 days. The production of MPO and the activation of calpain were reduced 52.17% and 36.67% by ECT in lens tissue, respectively. It modulated the energy status by significantly increasing the activity of CCO 1 (55.56%) and ATP production (41.88%). ECT maintained the ionic balance in the lens by reducing the level of sodium (50%) and increasing the level of potassium (42.5%). It also reduced cell junction modifications and preserved a functional ubiquitin-proteasome pathway. The results reinforce the growing attention on wild plant food resources for preventive protection against cataract. The data suggest the value of Cassia tora leaves as a functional food for ameliorating cataract pathology.

  3. Long-term efficacy and safety of sodium-glucose cotransporter-2 inhibitors as add-on to metformin treatment in the management of type 2 diabetes mellitus

    Science.gov (United States)

    Li, Jian; Gong, Yanping; Li, Chunlin; Lu, Yanhui; Liu, Yu; Shao, Yinghong

    2017-01-01

    Abstract Background: Drug intensification is often required for patients with type 2 diabetes mellitus on stable metformin therapy. Among the potential candidates for a combination therapy, sodium-glucose transporter-2 (SGLT2) inhibitors have shown promising outcomes. This meta-analysis was performed to compare the efficacy and safety of SGLT2 inhibitors with non-SGLT2 combinations as add-on treatment to metformin. Methods: Literature search was carried out in multiple electronic databases for the acquisition of relevant randomized controlled trials (RCTs) by following a priori eligibility criteria. After the assessment of quality of the included RCTs, meta-analyses of mean differences or odds ratios (OR) were performed to achieve overall effect sizes of the changes from baseline in selected efficacy and safety endpoints reported in the individual studies. Between-studies heterogeneity was estimated with between-studies statistical heterogeneity (I2) index. Results: Six RCTs fulfilled the eligibility criteria. SGLT2 inhibitors as add-on to metformin treatment reduced % HbA1c significantly more than non-SGLT2 combinations after 52 weeks (P = .002) as well as after 104 weeks (P SGLT2 inhibitors also reduced fasting plasma glucose levels, body weight, systolic, and diastolic blood pressures after 52 weeks and 104 weeks significantly (P SGLT2 combinations. Incidence of hypoglycemia was significantly lower (P = .02) but incidence of suspected or confirmed genital tract infections was significantly higher (P SGLT2 inhibitors treated in comparison with non-SGLT2 combinations. Conclusion: As add-on to metformin treatment, SGLT2 inhibitors are found significantly more efficacious than non-SGLT2 inhibitor combinations in the management of type 2 diabetes mellitus, although, SGLT2 inhibitor therapy is associated with significantly higher incidence of suspected or confirmed genital tract infections. PMID:28682870

  4. Removal and co-transport of Zn, As(V), and Cd during leachate seepage through downgradient mine soils: A batch sorption and column study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Juhee [Division of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of); Nam, Seung Mo [Korea Testing and Research Institute, Gyeonggi-do (Korea, Republic of); Hyun, Seunghun, E-mail: soilhyun@korea.ac.kr [Division of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of)

    2016-05-01

    The removal of Zn, As(V), and Cd during the leachate seepage process was measured in single, binary, and ternary solute systems by batch sorption and 1-D column flow experiments, followed by a sequential extraction procedure (SEP). In single-solute systems, sorption (K{sub d}{sup ⁎}) occurred in the order of As(V) > Zn ≫ Cd, and this sequence did not change in the presence of other solutes. In multi-solute systems, the sorption of Zn (~ 20%) and Cd (~ 27%) was enhanced by As(V), while Zn and Cd suppressed the sorption of each other. In all cases, As(V) sorption was not affected by the cations, indicating that As(V) is prioritized by sorption sites to a much greater degree than Zn and Cd. Element retention by column soils was strongly correlated (r{sup 2} = 0.77) with K{sub d}{sup ⁎}. Across column segments, mass retention was in the order of inlet (36–54%) > middle (26–35%) > outlet (20–31%), except for Cd in the Zn–Cd binary system. The result of SEP revealed that most of the retained Cd (98–99%) and Zn (56–71%) was in the labile fraction (e.g., the sum of F1 and F2) while only 9–12% of As(V) was labile and most (> 55%) was specifically adsorbed to Fe/Al oxides. Plots of the labile fraction (f{sub labile}) and the fast sorption fraction (f{sub fast}) suggested that the kinetics of specific As(V) sorption occur rapidly (f{sub fast} > f{sub labile}), whereas labile Zn and Cd sorption occurs slowly (f{sub labile} > f{sub fast}), indicating the occurrence of kinetically limited labile sorption sites, probably due to Zn–Cd competition. In conclusion, the element leaching potential of mine leachate can be greatly attenuated during downgradient soil seepage. However, when assessing the soil attenuation process, the impact of sorption competitors and the lability of adsorbed elements should first be considered. - Highlights: • During soil seepage, element leaching potential is reduced as As(V) > Zn > Cd. • Element removal during leachate seepage is well reflected by batch sorption data. • Zn–Cd competition suppresses each other's sorption, but being detrimental for Cd. • Of three elements, As(V) removal is thermodynamically and kinetically favored. • When assessing attenuation, the competitor and lability should be first considered.

  5. Disrupting Na+,HCO3--cotransporter NBCn1 (Slc4a7) delays murine breast cancer development

    DEFF Research Database (Denmark)

    Lee, S.; Axelsen, T. V.; Andersen, Anne Poder

    2016-01-01

    of NBCn1 genotype, the cleaved fraction of poly(ADP-ribose) polymerase (PARP)-1 and expression of monocarboxylate transporter (MCT)1 increased while phosphorylation of Akt and ERK1 decreased as functions of tumor volume. Cell proliferation, evaluated from Ki-67 and phospho-histone H3 staining, was ~60...

  6. Sodium-bicarbonate cotransporter NBCn1 in the kidney medullary thick ascending limb cell line is upregulated under acidic conditions and enhances ammonium transport.

    Science.gov (United States)

    Lee, Soojung; Lee, Hye Jeong; Yang, Han Soo; Thornell, Ian M; Bevensee, Mark O; Choi, Inyeong

    2010-09-01

    In this study, we examined the effect of bicarbonate transporters on ammonium/ammonia uptake in the medullary thick ascending limb cell line ST-1. Cells were treated with 1 mm ouabain and 0.2 mM bumetanide to minimize carrier-mediated NH(4)(+) transport, and the intracellular accumulation of (14)C-methylammonium/methylammonia ((14)C-MA) was determined. In CO(2)/HCO(3)(-)-free solution, cells at normal pH briefly accumulated (14)C-MA over 7 min and reached a plateau. In CO(2)/HCO(3)(-) solution, however, cells markedly accumulated (14)C-MA over the experimental period of 30 min. This CO(2)/HCO(3)(-)-dependent accumulation was reduced by the bicarbonate transporter blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonate (DIDS; 0.5 mM). Replacing Cl(-) with gluconate reduced the accumulation, but the reduction was more substantial in the presence of DIDS. Incubation of cells at pH 6.8 (adjusted with NaHCO(3) in 5% CO(2)) for 24 h lowered the mean steady-state intracellular pH to 6.96, significantly lower than 7.28 for control cells. The presence of DIDS reduced (14)C-MA accumulation in control conditions but had no effect after acidic incubation. Immunoblotting showed that NBCn1 was upregulated after acidic incubation and in NH(4)Cl-containing media. The Cl(-)-HCO(3)(-) exchanger AE2 was present, but its expression remained unaffected by acidic incubation. Expressed in Xenopus oocytes, NBCn1 increased carrier-mediated (14)C-MA transport, which was abolished by replacing Na(+). Two-electrode voltage clamp of oocytes exhibited negligible current after NH(4)Cl application. These results suggest that DIDS-sensitive HCO(3)(-) extrusion normally governs NH(4)(+)/NH(3) uptake in the medullary thick ascending limb cells. We propose that, in acidic conditions, DIDS-sensitive HCO(3)(-) extrusion is inactivated, while NBCn1 is upregulated to stimulate NH(4)(+) transport.

  7. Safety, tolerability, pharmacokinetics and pharmacodynamics of single doses of empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, in healthy Japanese subjects.

    Science.gov (United States)

    Sarashina, Akiko; Koiwai, Kazuki; Seman, Leo J; Yamamura, Norio; Taniguchi, Atsushi; Negishi, Takahiro; Sesoko, Shogo; Woerle, Hans J; Dugi, Klaus A

    2013-01-01

    This randomized, placebo-controlled within dose groups, double-blind, single rising dose study investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of 1 mg to 100 mg doses of empagliflozin in 48 healthy Japanese male subjects. Empagliflozin was rapidly absorbed, reaching peak levels in 1.25 to 2.50 h; thereafter, plasma concentrations declined in a biphasic fashion, with mean terminal elimination half-life ranging from 7.76 to 11.7 h. Increase in empagliflozin exposure was proportional to dose. Oral clearance was dose independent and ranged from 140 to 172 mL/min. In the 24 h following 100 mg empagliflozin administration, the mean (%CV) amount of glucose excreted in urine was 74.3 (17.1) g. The amount and the maximum rate of glucose excreted via urine increased with dose of empagliflozin. Nine adverse events, all of mild intensity, were reported by 8 subjects (7 with empagliflozin and 1 with the placebo). No hypoglycemia was reported. In conclusion, 1 mg to 100 mg doses of empagliflozin had a good safety and tolerability profile in healthy Japanese male subjects. Exposure to empagliflozin was dose proportional. The amount and rate of urinary glucose excretion were higher with empagliflozin than with the placebo, and increased with empagliflozin dose.

  8. In vitro studies of theophylline-induced changes in Na, K and Cl transport in hen (Gallus domesticus) colon suggesting bidirectional, basolateral NaK2Cl cotransport

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Munck, B G; Munck, L K

    1990-01-01

    1. In isolated mucosa from a NaCl-loaded hen theophylline stimulates both unidirectional chloride fluxes (JmsCl and JsmCl). Conductive and electroneutral exchange processes, besides a bumetanide-sensitive, rheogenic process contribute. 2. The bumetanide-sensitive fraction of the theophylline......-induced delta JcmCl is sodium-dependent. 3. Incubation in nominally K(+)-free solutions reduces the bumetanide-sensitive fraction delta JsmCl more than treatment with ouabain. 4. With respect to chloride the bumetanide-sensitive fraction of delta JsmCl has a Hill coefficient of 1.93 +/- 0.03, a Jmax of 12...

  9. Evidence that the rabbit proton-peptide co-transporter PepT1 is a multimer when expressed in Xenopus laevis oocytes.

    Science.gov (United States)

    Panitsas, Konstantinos-E; Boyd, C A R; Meredith, David

    2006-04-01

    To test whether the rabbit proton-coupled peptide transporter PepT1 is a multimer, we have employed a combination of transport assays, luminometry and site-directed mutagenesis. A functional epitope-tagged PepT1 construct (PepT1-FLAG) was co-expressed in Xenopus laevis oocytes with a non-functional but normally trafficked mutant form of the same transporter (W294F-PepT1). The amount of PepT1-FLAG cRNA injected into the oocytes was kept constant, while the amount of W294F-PepT1 cRNA was increased over the mole fraction range of 0 to 1. The uptake of [(3)H]-D: -Phe-L: -Gln into the oocytes was measured at pH(out) 5.5, and the surface expression of PepT1-FLAG was quantified by luminometry. As the mole fraction of injected W294F-PepT1 increased, the uptake of D: -Phe-L: -Gln decreased. This occurred despite the surface expression of PepT1-FLAG remaining constant, and so we can conclude that PepT1 must be a multimer. Assuming that PepT1 acts as a homomultimer, the best fit for the modelling suggests that PepT1 could be a tetramer, with a minimum requirement of two functional subunits in each protein complex. Western blotting also showed the presence of higher-order complexes of PepT1-FLAG in oocyte membranes. It should be noted that we cannot formally exclude the possibility that PepT1 interacts with unidentified Xenopus protein(s). The finding that PepT1 is a multimer has important implications for the molecular modelling of this protein.

  10. General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt

    KAUST Repository

    Lacoh, Claudia Marvine; Bodogan, T.; Kaila, Kai K.; Fiumelli, Hubert; Vutskits, Lá szló

    2013-01-01

    . However, it is not known whether early neuronal activity plays a modulatory role in the expression of total KCC2 mRNA and protein in the immature brain. As general anaesthetics are powerful modulators of neuronal activity, the purpose of this study

  11. Inhibition of sodium glucose cotransporter-I expressed in Xenopus laevis oocytes by 4-acetoxyscirpendiol from Cordyceps takaomantana (anamorph = Paecilomyces tenuipes).

    Science.gov (United States)

    Yoo, Ocki; Lee, Dong-Hee

    2006-02-01

    Cordyceps contains many health-promoting constituents. Recent studies revealed that the fruiting body of cordyceps significantly alleviates hyperglycemia which usually accompanies diabetes mellitus. The mechanism of the anti-hyperglycemic effect by cordyceps, however, is not fully understood. In this study, methanolic extracts were prepared from fruiting bodies of Paecilomyces tenuipes, and 4-beta acetoxyscirpendiol (ASD) was eventually purified from the extracts. The Na+/ glucose transporter-1 (SGLT-1) was expressed in Xenopus oocytes, and the effect of ASD on it was analyzed using voltage clamp and 2-deoxy-D-glucose (2-DOG) uptake studies. Fluorescence microscopy was performed to monitor the effect of ASD on glucose uptake using HEK293 cells expressing recombinant SGLT-1. ASD inhibited SGLT-1 activity, and its two derivatives (2-acetoxyscirpenol and 15-acetoxyscirpendiol), were also effective; 15-acetoxyscirepenol was as inhibitory as ASD while diacetoxyscirpenol had less effect. Thus, the ASD in P. tenuipes may play an important role in lowering blood sugar in the circulatory system along with its derivatives as specific inhibitors of SGLT-1.

  12. Dexmedetomidine attenuates persistent postsurgical pain by upregulating K+–Cl− cotransporter-2 in the spinal dorsal horn in rats

    Directory of Open Access Journals (Sweden)

    Dai S

    2018-05-01

    Full Text Available Shuhong Dai,1 Yu Qi,1 Jie Fu,1 Na Li,1 Xu Zhang,1 Juan Zhang,2 Wei Zhang,2 Haijun Xu,1 Hai Zhou,1 Zhengliang Ma2 1Department of Anesthesiology, XuZhou Central Hospital, Xuzhou, China; 2The Affiliated Nanjing Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China Background: Dexmedetomidine (DEX could have an analgesic effect on pain transmission through the modulation of brain-derived neurotrophic factor (BDNF. In addition, KCC2-induced shift in neuronal Cl- homeostasis is crucial for postsynaptic inhibition mediated by GABAA receptors. Accumulating evidence shows that nerve injury, peripheral inflammation and stress activate the spinal BDNF/TrkB signal, which results in the downregulation of KCC2 transport and expression, eventually leads to GAGAergic disinhibition and hyperalgesia. The aim of this experiment was to explore the interaction between DEX and KCC2 at a molecular level in rats in the persistent postsurgical pain (PPSP. Methods: PPSP in rats was evoked by the skin/muscle incision and retraction (SMIR. Mechanical hypersensitivity was assessed with the Dynamic Plantar Aesthesiometer. Western blot and immunofluorescence assay were used to assess the expressions of related proteins. Results: In the first part of our experiment, the results revealed that the BDNF/TrkB-KCC2 signal plays a critical role in the development of SMIR-evoked PPSP; the second part showed that intraperitoneal administrations of 40 µg/kg DEX at 15 min presurgery and 1 to 3 days post-surgery significantly attenuated SMIR-evoked PPSP. Simultaneously, SMIR-induced KCC2 downregulation was partly reversed, which coincided with the inhibition of the BDNF/TrkB signal in the spinal dorsal horn. Moreover, intrathecal administrations of KCC2 inhibitor VU0240551 significantly reduced the analgesic effect of DEX on SMIR-evoked PPSP. Conclusion: The results of our study indicated that DEX attenuated PPSP by restoring KCC2 function through reducing BDNF/TrkB signal in the spinal dorsal horn in rats, which provides a new insight into the treatment of chronic pain in clinical postsurgical pain management. Keywords: skin/muscle incision and retraction, persistent postsurgical pain, dexmedetomidine, KCC2, BDNF/TrkB signal

  13. Novel roles of the Na+/H+ exchanger NHE1 and the Na+,HCO3 - cotransporter NBCn1 in cell survival, proliferation and motility

    DEFF Research Database (Denmark)

    Thorup, Gitte Ehrenreich

    and cell motility. The molecular mechanisms contributing to altered pHi regulation in cancer cells are incomplete understood. Overexpression of ErbB2 is common in breast cancer and the expression of an N-terminally truncated, constitutively active ErbB2 receptor (ΔNErbB2) is associated with increased....... Pharmacological inhibition of NHE1 enhances cisdiamminedichloroplatinum (II) (cisplatin) induced cell death, especially in ΔNErbB2 expressing cells. In Paper III we show that upon cisplatin treatment, expression of ΔNErbB2 results in increased caspase-9 and -7 cleavage, which is further augmented by specific...... inhibition of NHE1. Moreover, NBCN1, yet not NHE1, is lost from the plasma membrane upon cisplatin treatment, and this may explain why inhibition of NHE1 sensitizes the cells to cisplatin-induced cell death. In Paper II we show that in MCF-7 breast cancer cells, the expression levels of NBCn1 and NHE1...

  14. An Investigation of the Stoichiometry of Na+ Cotransport with Dopamine in Rat and Human Dopamine Transporters Expressed in Human Embryonic Kidney Cells

    National Research Council Canada - National Science Library

    Schumacher, Paul

    2001-01-01

    The neuronal membrane transporter for dopamine (DAT) is a member of the Na+ and Cl dependent family of transporters and concentrates dopamine intracellularly up to 106 fold over extracellular levels...

  15. Assessing the Potential Consequences of Subsurface Bioremediation: Fe-oxide Bioreductive Processes and the Propensity for Contaminant-colloid Co-transport and Media Structural Breakdown

    Science.gov (United States)

    2017-05-12

    clay particles together into aggregates ( Goldberg and Glaubig, 1987; Goldberg et al., 1990). Reduction of Fe(III)-oxide under anaerobic conditions...cryptic Phylum. To confirm that the changes in the relative abundance of the Phylum Proteobacteria was likely due variation in the abundance and...bioremediation. Environmental Science and Technology 34 (11), 2254–2260. DOI: 10.1021/es990638e 10. Goldberg , S., and R.A. Glaubig. 1987. Effect of saturating

  16. One step closer to an experimental infection system for Hepatitis B Virus? --- the identification of sodium taurocholate cotransporting peptide as a viral receptor

    Directory of Open Access Journals (Sweden)

    Chen Pei-Jer

    2013-01-01

    Full Text Available Abstract Following the successful cloning of receptor for SARS coronavirus a few years ago, Dr. Wenhui Li and colleagues raised attention again by publishing a possible receptor for hepatitis B virus in eLife. We will briefly review the significance of this finding and the future prospects of hepatitis B research.

  17. Retraction Note to: Compensatory role of the NBCn1 sodium/bicarbonate cotransporter on Ca2+-induced mitochondrial swelling in hypertrophic hearts.

    Science.gov (United States)

    Vargas, Lorena A; Velasquez, Fernanda Carrizo; Alvarez, Bernardo V

    2018-04-18

    The authors have retracted this article [1] because of modifications in the control lanes of Figs. 2a and 8a of the COX1 blot obtained for 18-week-old rats (rotation, horizontal flipping and re-use of the control lanes for the 35-week-old rats blot). In light of the concerns raised, the conclusions drawn in this article cannot be relied upon.

  18. Characterization and mechanical properties of coatings on magnesium by micro arc oxidation

    International Nuclear Information System (INIS)

    Durdu, Salih; Usta, Metin

    2012-01-01

    Highlights: ► The commercial pure magnesium was coated by MAO in sodium silicate and sodium phosphate. ► Coatings produced in the phosphate electrolyte are thicker than ones in the silicate electrolyte. ► Coatings in the silicate electrolyte are harder than ones in the phosphate electrolyte. ► Adhesion strength of coatings increases with increasing coating thickness. ► The wear resistance of the coated commercial pure magnesium is improved. - Abstracts: The commercial pure magnesium was coated by micro arc oxidation method in different aqueous solution, containing sodium silicate and sodium phosphate. Micro arc oxidation process was carried out at 0.060 A/cm 2 , 0.085 A/cm 2 and 0.140 A/cm 2 current densities for 30 min. The thickness, phase composition, morphology, hardness, adhesion strength and wear resistance of coatings were analyzed by eddy current, X-ray diffraction (XRD), scanning electron microscope (SEM), micro hardness tester, scratch tester and ball-on disk tribometer, respectively. The average thicknesses of the micro arc oxidized coatings ranged from 27 to 48 μm for sodium silicate solution and from 45 to 75 μm for sodium phosphate solution. The dominant phases formed on the pure magnesium were found to be a mixture of spinel Mg 2 SiO 4 (Forsterite) and MgO (Periclase) for sodium silicate solution and Mg 3 (PO 4 ) 2 (Farringtonite) and MgO (Periclase) for sodium phosphate solution. The average hardnesses of the micro arc oxidized coatings were between 260 HV and 470 HV for sodium silicate solution and between 175 HV and 260 HV for sodium phosphate solution. Adhesion strengths and wear resistances of coatings produced in sodium silicate solution were higher than those of the ones in sodium phosphate solution due to high hardness of coatings produced in sodium silicate solution.

  19. The safety of osmotically acting cathartics in colonic cleansing

    DEFF Research Database (Denmark)

    Nyberg, Caroline; Hendel, J.; Nielsen, O.H.

    2010-01-01

    Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate...... hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal...

  20. SwissProt search result: AK069337 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK069337 J023014F07 (Q28727) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  1. SwissProt search result: AK072870 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK072870 J023142A17 (Q28727) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  2. SwissProt search result: AK104932 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104932 001-047-B10 (Q28727) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transp

  3. SwissProt search result: AK104932 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104932 001-047-B10 (Q60414) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transp

  4. SwissProt search result: AK072870 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK072870 J023142A17 (Q60414) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  5. SwissProt search result: AK069337 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK069337 J023014F07 (Q60414) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  6. SwissProt search result: AK069337 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK069337 J023014F07 (P70172) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  7. SwissProt search result: AK072870 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK072870 J023142A17 (P70172) Ileal sodium/bile acid cotransporter (Ileal Na(+)/bile... acid cotransporter) (Na(+) dependent ileal bile acid transporter) (Ileal sodium-dependent bile acid transpo

  8. Water transport in the brain

    DEFF Research Database (Denmark)

    MacAulay, N; Hamann, S; Zeuthen, T

    2004-01-01

    the number of cotransporters per cell and the unit water permeability are high. For example, the Na(+)-glutamate cotransporter (EAAT1) has a unit water permeability one tenth of that of aquaporin (AQP) 1. Cotransporters are widely distributed in the brain and participate in several vital functions: inorganic...

  9. Gravimetric Analysis of Bismuth in Bismuth Subsalicylate Tablets: A Versatile Quantitative Experiment for Undergraduate Laboratories

    Science.gov (United States)

    Davis, Eric; Cheung, Ken; Pauls, Steve; Dick, Jonathan; Roth, Elijah; Zalewski, Nicole; Veldhuizen, Christopher; Coeler, Joel

    2015-01-01

    In this laboratory experiment, lower- and upper-division students dissolved bismuth subsalicylate tablets in acid and precipitated the resultant Bi[superscript 3+] in solution with sodium phosphate for a gravimetric determination of bismuth subsalicylate in the tablets. With a labeled concentration of 262 mg/tablet, the combined data from three…

  10. Palmitate and stearate binding to human serum albumin. Determination of relative binding constants

    DEFF Research Database (Denmark)

    Vorum, H; Fisker, K; Honoré, B

    1997-01-01

    Multiple binding equilibria of two apparently insoluble ligands, palmitate and stearate, to defatted human serum albumin were studied in a 66 mM sodium phosphate buffer (pH 7.4) at 37 degrees C, by determination of dialytic exchange rates of ligands among identical equilibrium solutions. The expe...

  11. A new paramagnetic center of copper ion γ-irradiated phosphate glasses

    International Nuclear Information System (INIS)

    Bogomolova, L.D.; Fedorov, A.G.; Jachkin, V.A.; Lazukin, V.N.; Pavlushkina, T.K.

    1981-01-01

    In the present paper are shown the results of EPR and optical absorption investigations of copper ions in γ-irradiated sodium-phosphate glasses and in MO-P 2 O 5 glasses (M = MG,Ca, Sr, Zn, Ba) containing copper and comparisons are made with the data for sodium-silicate glasses. (orig./HOF)

  12. Histological study on the effect of transplanted human umbilical cord ...

    African Journals Online (AJOL)

    ways to manage heart failure by replacing damaged cardiac muscle with healthy tissue. This study aimed at examining .... sodium phosphate buffer, pH 7.4 at room temperature. Specimens were dehydrated in ascending grades of cold ethanol and ..... been shown to express angiogenic growth factors in a paracrine way to ...

  13. Dgroup: DG00410 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available DG00410 Chemical ... DGroup Methylprednisolone ... D00407 ... Methylprednisolone (JP17/USP.../INN) ... D00751 ... Methylprednisolone sodium succinate (JAN/USP) ... D00979 ... Methylprednisolone acetate (JAN/US...P) ... D05000 ... Methylprednisolone hemisuccinate (USP); Methylprednisolone succinate (JP17) D05001 ... Methylprednisolo...ne sodium phosphate (USAN) D05002 ... Methylprednisolone suleptanate (USAN/INN) D07203 ... Methylprednisol

  14. Production of extracellular amylase from agricultural residues by a ...

    African Journals Online (AJOL)

    ONOS

    2010-08-09

    Aug 9, 2010 ... parameter optimized in one experiment was maintained at its optimum level in further experiments. Enzyme extraction. Alpha amylase was extracted from SSF medium by a simple contact method (Ramesh and Lonsane, 1990). After specified incubation time in each case, 100 ml of sodium phosphate buffer.

  15. antioxidant activity of the inflorescents of vernonia calvoana growing

    African Journals Online (AJOL)

    using an electric stainless steel mill at the Department of. Chemistry, University of .... was added to 1ml of reagent (0.6MH2SO4, 0.028M sodium phosphate 0.004M .... tannins, Cyanides and phytates confer on it the ability to aid in absorption of ...

  16. 21 CFR 201.66 - Format and content requirements for over-the-counter (OTC) drug product labeling.

    Science.gov (United States)

    2010-04-01

    ... throat warning:” (G) Warning for drug products containing sodium phosphates set forth in § 201.307(b)(2... (excluding pregnancy) and all warnings for persons experiencing certain symptoms. The warnings under this... paragraphs (c)(5)(i) through (c)(5)(vii), (c)(5)(ix), and (c)(5)(x) of this section. (ix) The pregnancy...

  17. Intumescent all-polymer multilayer nanocoating capable of extinguishing flame on fabric

    Science.gov (United States)

    Cotton fabric was treated with flame-retardant coatings composed of poly (sodium phosphate), PSP, which acts as the acid source, and poly (allylamine), PAAm, which is used as the blowing agent, prepared via layer-by-layer (LbL) assembly. By applying these thin coating on fabric, after-glow is elimi...

  18. Recovery of thorium from monazite

    International Nuclear Information System (INIS)

    Karve, V.M.; Mukherjee, T.K.

    1997-01-01

    The process practised in the monazite processing plant involves caustic soda digestion of finely ground monazite followed by aqueous processing to recover mixed rare earth chloride solution, thorium and uranium values in the form of hydroxide cake and tri sodium phosphate as a byproduct

  19. Drug: D05870 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ythemia vera [DS:H00012] Chronic myelocytic leukemia [DS:H00004] Chronic lymphocyti... D05870 Drug Sodium phosphate P 32 (USP); Phosphotope (TN) ... HPO4. 2Na D05870.gif ... ATC code: V10XX01 Polyc

  20. Impacts of Sampling and Handling Procedures on DNA- and RNA-based Microbial Characterization and Quantification of Groundwater and Saturated Soil

    Science.gov (United States)

    2012-07-01

    Interference of soil extracts and of the matrix itself (e.g., sand, clay, compost , activated carbon) to the derived DNA quantity and quality is often...phase. Both cultures were washed twice in sodium phosphate buffer, combined and inoculated to 100 g of homogenized soil at a moisture content

  1. Influence of high-conductivity buffer composition on field-enhanced sample injection coupled to sweeping in CE.

    Science.gov (United States)

    Anres, Philippe; Delaunay, Nathalie; Vial, Jérôme; Thormann, Wolfgang; Gareil, Pierre

    2013-02-01

    The aim of this work was to clarify the mechanism taking place in field-enhanced sample injection coupled to sweeping and micellar EKC (FESI-Sweep-MEKC), with the utilization of two acidic high-conductivity buffers (HCBs), phosphoric acid or sodium phosphate buffer, in view of maximizing sensitivity enhancements. Using cationic model compounds in acidic media, a chemometric approach and simulations with SIMUL5 were implemented. Experimental design first enabled to identify the significant factors and their potential interactions. Simulation demonstrates the formation of moving boundaries during sample injection, which originate at the initial sample/HCB and HCB/buffer discontinuities and gradually change the compositions of HCB and BGE. With sodium phosphate buffer, the HCB conductivity increased during the injection, leading to a more efficient preconcentration by staking (about 1.6 times) than with phosphoric acid alone, for which conductivity decreased during injection. For the same injection time at constant voltage, however, a lower amount of analytes was injected with sodium phosphate buffer than with phosphoric acid. Consequently sensitivity enhancements were lower for the whole FESI-Sweep-MEKC process. This is why, in order to maximize sensitivity enhancements, it is proposed to work with sodium phosphate buffer as HCB and to use constant current during sample injection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Enumeration of sugars and sugar alcohols hydroxyl groups by aqueous-based acetylation and MALDI-TOF mass spectrometry

    Science.gov (United States)

    A method is described for enumerating hydroxyl groups on analytes in aqueous media is described, and applied to some common polyalcohols (erythritol, mannitol, and xylitol) and selected carbohydrates. The analytes were derivatized in water with vinyl acetate in presence of sodium phosphate buffer. ...

  3. A study on adverse drug reactions in a tertiary care hospital of ...

    African Journals Online (AJOL)

    Acne (46) was commonly reported reaction. Topical steroids, betamethasone sodium phosphate and clobetasol were reported to induce maximum number of reactions (59). Skin (227, 66.9%) was commonly affected organ system. Most of the adverse drug reactions were possible (240, 94.1%) and mild (222, 87%) in nature.

  4. Akut fosfatnefropati som komplikation til udrensning med oral natriumfosfat

    DEFF Research Database (Denmark)

    Colic, Edin; Marcussen, Niels

    2011-01-01

    Acute phosphate nephropathy (APhN) has recently been identified as a reason for acute and subsequently chronic renal failure, following exposure to the oral sodium phosphate bowel purgatives. Renal biopsies show acute and chronic tubular injury with calcium phosphate deposits. A case of biopsy...

  5. Molecular basis of indomethacin-human serum albumin interaction

    DEFF Research Database (Denmark)

    Trivedi, V D; Vorum, H; Honoré, B

    1999-01-01

    Studies on the strength and extent of binding of the non-steroidal anti-inflammatory drug indomethacin to human serum albumin (HSA) have provided conflicting results. In the present work, the serum-binding of indomethacin was studied in 55 mM sodium phosphate buffer (pH 7.0) at 28 degrees C, by u...

  6. Gene Expression in the Human Endolymphatic Sac

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Kirkeby, Svend; Vikeså, Jonas

    2015-01-01

    a1 sodium-bicarbonate transporter, SLC9a2 sodium-hydrogen transporter, SLC12a3 thiazide-sensitive Na-Cl transporter, and SLC34a2 sodium-phosphate transporter. CONCLUSIONS: Several important ion transporters of the SLC family are expressed in the human endolymphatic sac, including Pendrin...

  7. Non-severe Hypoglycemia Risk Difference between Sulfonylurea and Sodium-Glucose Cotransporter-2 Inhibitors (SGLT2-I) as an Add-On to Metformin in Randomized Controlled Trials.

    Science.gov (United States)

    Farahani, Pendar

    2017-05-23

    Non-severe hypoglycemia reduces well-being, lowers quality of life, reduces productivity and increases treatment costs. The non-severe hypoglycemia rate, attributable to sulfonylurea (SU) utilization compared with newer classes such as SGLT2-I, could be of clinical significance. To explore the non-severe hypoglycemia risk difference (RD) for SU use compared with SGLT2-I in randomized controlled trials (RCTs) as an add on to metformin. A search was conducted for RCTs of SGLT2-I. PubMed database were utilized for this search. The search was limited to RCTs reported in English language for canagliflozin, dapagliflozin, and empagliflozin. SU dose comparison was utilized to convert the dose of SUs to glimepiride equivalent doses. Totally, 118 RCTs were reviewed; 6 articles had an arm for a SU as add on to metformin. Six articles belong to 3 RCTs, which reported results for 52 weeks and 104 weeks. Average non-severe hypoglycemia rate for SU arm was 30% (5.5%) [Mean (SD)] for 52 weeks and 35.6% (6.1%) for 104 weeks. RD for non-severe hypoglycemia events for SU compared to SGLT2-I was 26.7% (4.9%) for 52 weeks (p-value less than 0.001) and 30.6% (5.5%) for 104 weeks (p-value less than 0.001). There was a significant correlation between dose of SU and hypoglycemia rate (Pearson correlation 0.995; R-square 99%). This study illustrated that a large proportion of patients who had exposure to SU in RCTs of SGLT2-I experienced non-severe hypoglycemia compared to SGLT2-I. There was a close relation between SU dose and increased probability of non-severe hypoglycemia events. © 2017 Journal of Population Therapeutics and Clinical Pharmacology. All rights reserved.

  8. Modulation of sodium-bicarbonate co-transporter (SLC4A4/NBCe1) protein and mRNA expression in rat's uteri by sex-steroids and at different phases of the oestrous cycle.

    Science.gov (United States)

    Gholami, Khadijeh; Muniandy, Sekaran; Salleh, Naguib

    2014-02-01

    Oestrogen-induced uterine fluid sodium (Na(+)) and bicarbonate (HCO3(-)) secretion may involve SLC4A4. We hypothesized that uterine SLC4A4 expression changes under different sex-steroid influence, therefore may account for the fluctuation in uterine fluid Na(+) and HCO3(-) content throughout the oestrous cycle. The aim of this study is to investigate the differential effects of sex-steroids and oestrous cycle phases on uterine SLC4A4 expression. Adult female WKY rats were ovariectomised and treated with different doses of 17β-oestradiol (E2) (0.2, 2, 20 and 50 μg/ml/day) or progesterone (P4) (4 mg/ml/day) for three consecutive days and 3 days treatment with 0.2 μg/ml/day E2 followed by another 3 days with P4 to mimic the hormonal changes in early pregnancy. Oestrous cycle phases in intact, non-ovariectomised rats were determined by vaginal smear. The animals were then sacrificed and uteri were removed for protein and mRNA expression analyses by Western blotting and Real Time PCR, respectively. SLC4A4 distribution was observed by immunohistochemistry. Treatment with increasing E2 doses resulted in a dose-dependent increase in SLC4A4 protein expression. High SLC4A4 protein and mRNA expression can be seen at estrus. SLC4A4 is distributed mainly at the apical as well as basolateral membranes of the luminal and glandular epithelia following E2 treatment and at Es. Meanwhile, SLC4A4 expression was reduced following P4 treatment and was low at diestrus. High SLC4A4 expression under estrogen dominance may contribute to the increase in uterine fluid Na(+) and HCO3(-) content, while its low expression under P4 dominance may result in vice versa. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Evaluating the involvement of cerebral microvascular endothelial Na+/K+-ATPase and Na+-K+-2Cl- co-transporter in electrolyte fluxes in an in vitro blood-brain barrier model of dehydration

    DEFF Research Database (Denmark)

    Lykke, Kasper; Assentoft, Mette; Hørlyck, Sofie

    2018-01-01

    The blood-brain barrier (BBB) is involved in brain water and salt homeostasis. Blood osmolarity increases during dehydration and water is osmotically extracted from the brain. The loss of water is less than expected from pure osmotic forces, due to brain electrolyte accumulation. Although...... dehydration, we employed a tight in vitro co-culture BBB model with primary cultures of brain endothelial cells and astrocytes. The Na+/K+-ATPase and the NKCC1 were both functionally dominant in the abluminal membrane. Exposure of the in vitro BBB model to conditions mimicking systemic dehydration, i...... isozymes. Abluminally expressed endothelial Na+/K+-ATPase, and not NKCC1, may therefore counteract osmotic brain water loss during systemic dehydration by promoting brain Na+ accumulation....

  10. Increased NBCn1 expression, Na+/HCO3 co-transport and intracellular pH in human vascular smooth muscle cells with a risk allele for hypertension

    DEFF Research Database (Denmark)

    Ng, Fu Liang; Boedtkjer, Ebbe; Witkowska, Katarzyna

    2017-01-01

    cultures of vascular smooth muscle and endothelial cells. In both cell types, we found genotype-dependent differences for rs13082711 in DNA-nuclear protein interactions, where the risk allele is associated with increased SLC4A7 expression level, NBCn1 availability and function as reflected in elevated...

  11. Combination of the sodium-glucose cotransporter-2 inhibitor empagliflozin with orlistat or sibutramine further improves the body-weight reduction and glucose homeostasis of obese rats fed a cafeteria diet

    Directory of Open Access Journals (Sweden)

    Vickers SP

    2014-07-01

    Full Text Available Steven P Vickers,1 Sharon C Cheetham,1 Katie R Headland,1 Keith Dickinson,1 Rolf Grempler,2 Eric Mayoux,2 Michael Mark,2 Thomas Klein2 1RenaSci, BioCity Nottingham, Nottingham, UK; 2Boehringer Ingelheim Pharma, Biberach an der Riss, Germany Abstract: The present study assessed the potential of the sodium glucose-linked transporter (SGLT-2 inhibitor empagliflozin to decrease body weight when administered alone or in combination with the clinically effective weight-loss agents orlistat and sibutramine in obese rats fed a cafeteria diet. Female Wistar rats were exposed to a cafeteria diet to induce obesity. Empagliflozin was dosed once daily (10, 30, and 60 mg/kg for 28 days. Combination studies were subsequently performed using a submaximal empagliflozin dose (10 mg/kg with either sibutramine or orlistat. Body weight, food, and water intake were recorded daily. The effect of drug treatment on glucose tolerance, relevant plasma parameters, and carcass composition was determined. Empagliflozin dose-dependently reduced body weight, plasma leptin, and body fat though increased urinary glucose excretion. The combination of empagliflozin and orlistat significantly reduced body weight compared to animals treated with either drug alone, and significantly improved glucose tolerance, plasma insulin, and leptin compared to vehicle-treated controls. The effect of sibutramine to improve glycemic control in an oral glucose-tolerance test was also significantly increased, with empagliflozin and combination treatment leading to a reduction in carcass fat greater than that observed with either drug alone. These data demonstrate that empagliflozin reduces body weight in cafeteria-fed obese rats. In combination studies, empagliflozin further improved the body-weight or body-fat loss of animals in comparison to orlistat or sibutramine alone. Such studies may indicate improved strategies for the treatment of obese patients with prediabetes or type 2 diabetes. Keywords: SGLT2, empagliflozin, sibutramine, obesity, rat, combination

  12. Combination of the sodium-glucose cotransporter-2 inhibitor empagliflozin with orlistat or sibutramine further improves the body-weight reduction and glucose homeostasis of obese rats fed a cafeteria diet.

    Science.gov (United States)

    Vickers, Steven P; Cheetham, Sharon C; Headland, Katie R; Dickinson, Keith; Grempler, Rolf; Mayoux, Eric; Mark, Michael; Klein, Thomas

    2014-01-01

    The present study assessed the potential of the sodium glucose-linked transporter (SGLT)-2 inhibitor empagliflozin to decrease body weight when administered alone or in combination with the clinically effective weight-loss agents orlistat and sibutramine in obese rats fed a cafeteria diet. Female Wistar rats were exposed to a cafeteria diet to induce obesity. Empagliflozin was dosed once daily (10, 30, and 60 mg/kg) for 28 days. Combination studies were subsequently performed using a submaximal empagliflozin dose (10 mg/kg) with either sibutramine or orlistat. Body weight, food, and water intake were recorded daily. The effect of drug treatment on glucose tolerance, relevant plasma parameters, and carcass composition was determined. Empagliflozin dose-dependently reduced body weight, plasma leptin, and body fat though increased urinary glucose excretion. The combination of empagliflozin and orlistat significantly reduced body weight compared to animals treated with either drug alone, and significantly improved glucose tolerance, plasma insulin, and leptin compared to vehicle-treated controls. The effect of sibutramine to improve glycemic control in an oral glucose-tolerance test was also significantly increased, with empagliflozin and combination treatment leading to a reduction in carcass fat greater than that observed with either drug alone. These data demonstrate that empagliflozin reduces body weight in cafeteria-fed obese rats. In combination studies, empagliflozin further improved the body-weight or body-fat loss of animals in comparison to orlistat or sibutramine alone. Such studies may indicate improved strategies for the treatment of obese patients with prediabetes or type 2 diabetes.

  13. Cardiovascular mortality and morbidity in patients with type 2 diabetes following initiation of sodium-glucose co-transporter-2 inhibitors versus other glucose-lowering drugs (CVD-REAL Nordic)

    DEFF Research Database (Denmark)

    Birkeland, Kåre I.; Jørgensen, Marit E.; Carstensen, Bendix

    2017-01-01

    , and atrial fibrillation. We also assessed incidence of severe hypoglycaemia. Findings Matched SGLT2 inhibitor (n=22 830) and other glucose-lowering drug (n=68 490) groups were well balanced at baseline, with a mean follow-up of 0·9 (SD 4·1) years (80 669 patient-years) and mean age of 61 (12·0) years; 40...... with the results of clinical trials in patients at high cardiovascular risk. Funding AstraZeneca....

  14. Use of fractional factorial design for selection of nutrients for culturing Paecilomyces variotii in eucalyptus hemicellulosic hydrolysate

    Directory of Open Access Journals (Sweden)

    J.B. Almeida e Silva

    1998-09-01

    Full Text Available A eucalyptus hemicellulose fraction was hydrolysed by treating eucalyptus wood chips with sulfuric acid. The hydrolysate was used as the substrate to grow Paecilomyces variotii IOC-3764 cultured for 72 or 96 hours. The influence of the inhibitors, nutrients and fermentation time was verified by a 28-4 and, subsequently, a 25-1 fractional factorial design. The effects of the inhibitors (acetic acid and furfural, nutrients (rice bran, urea, potassium nitrate, ammonium sulfate, magnesium sulfate and sodium phosphate and fermentation time were investigated. The highest yield (10.59 g/L of biomass was obtained when the microorganisms were cultivated for 72 hours in a medium composed of 30 g/L rice bran, 9.4 g/L ammonium sulfate (2 g/L nitrogen and 2 g/L sodium phosphate.

  15. Extreme hyperphosphatemia and hypocalcemic coma associated with phosphate enema.

    Science.gov (United States)

    Hsu, Heng Jung; Wu, Mai-Szu

    2008-01-01

    Fleet enema (sodium phosphate, C.B. Fleet Co., Inc., Lynchburg, Virginia) is widely used for bowel preparation or constipation relief in the hospital and over the counter. The potential risks, including hyperphosphatemia and hypocalcemic coma should be kept in mind of primary care physician. The patients with older age, bowel obstruction, small intestinal disorders, poor gut motility, and renal disease are contraindicated or should be administered with caution. We present a patient with old age and chronic renal failure who developed severe hyperphosphatemia and hypocalcemic tetany with coma after sodium phosphate enema. We recommend the use of alternative enema preparations, such as simple tap water or saline solution enemas, which can prevent fatal complications in high risk patients.

  16. A critical evaluation and a search for the ideal colonoscopic preparation.

    Science.gov (United States)

    Arora, Manish; Senadhi, Viplove; Arora, Deepika; Weinstock, Joyce; Dubin, Ethan; Okolo, Patrick I; Dutta, Sudhir K

    2013-04-01

    The aim of this study was to evaluate the efficacy of various bowel preparations in accomplishing colonic cleansing for optimal mucosal visualization during colonoscopy. The study included a cohort of 980 patients who underwent colonoscopy at our endoscopy center within the last 3 years. All of the study patients were subdivided into four groups. Each group included 245 patients, all receiving a different type of bowel preparation. The bowel preparations used in this study included: magnesium citrate (Group I), a combination of oral sodium phosphate (fleets) and powder PEG-3350 (Group II), powder polyethylene glycol-3350 (PEG-3350 powder for Group III), and oral sodium phosphate (fleets for Group IV). A Colon Prep Score (CPS) was devised to compare the quality of the different bowel preparations used. The colonoscopy results from all of these patients were tabulated and analyzed statistically and expressed as mean ± 1 standard deviation. Statistical analysis was performed using a one way ANOVA with Holm-Sidak method for intergroup analysis. Group I patients received magnesium citrate and had a mean CPS ± 1 SD of 3.11 ± 0.91. Group II patients (fleets and powder PEG-3350 combination) achieved a CPS of 3.37 ± 1.16. The patients in Group III (powder PEG-3350) actually showed the highest mean CPS of 3.44 ± 1.12. Group IV patients who used oral sodium phosphate alone reached a mean CPS of 3.23 ± 1.01. Group III patients (powder PEG-3350 only) demonstrated a statistically higher CPS (PPEG-3350 combination) also showed improved colon cleansing statistically (PPEG-3350 alone and in combination with oral sodium phosphate was observed to be statistically superior to magnesium citrate, when used for colon preparation for colonoscopy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Vapor Inhalation Exposure to Soman in Conscious Untreated Rats: Preliminary Assessment of Neurotoxicity

    Science.gov (United States)

    2015-12-22

    cholinergic crises including salivation , lacrimation, increased urination and defecation, and tremors were observed in all soman-exposed animals. Soman...Clinical/observational signs and body weight loss Clinical signs, including salivation , lacrimation, defecation, urination, facial clonus, tremors...additional 290 mL of working solution consisting of 50mM sodium phosphate buffer ( pH 8.0), 1mM acetylthio- choline iodide (ATC) and 0.2mM of the chromophore

  18. Pengaruh Jenis Koagulan Terhadap Viskositas Larutan Pencuci Piring (Dishwashing Liquid)

    OpenAIRE

    Pasaribu, Osbal Sugondo

    2012-01-01

    Research on the influence of coagulant type on the viscosity of the dishwashing liquid has been done. Dishwashing solution that is used as a sample obtained from a mixture of sodium lauryl sulfate, sodium lauryl ether sulfate, a coagulant, fragrance lemon and water. Coagulant used is a solution of sodium chloride 30%, solution of sodium sulfate 15% and sodium phosphate solution of 10%. Solution viscosity was measured after the addition of a dishwasher using Viscosimeter Ostwald coagulant. The...

  19. Spectrophotometric determination of copper in alkaline solutions and evaluation of some hydroxy-substituted 1,10-phenanthrolines as chromogenic reagents.

    Science.gov (United States)

    Dunbar, W E; Schilt, A A

    1972-09-01

    Seven new hydroxy-substituted 1,10-phenanthroline derivatives have been evaluated as chromogenic reagents for the determination of copper in strongly alkaline solution. The most sensitive of these, 2,9-dimethyl-4,7-dihydroxy-1,10-phenanthroline, has proven to be highly effective in a simple, rapid procedure for determining trace amounts of copper in sodium hydroxide, potassium carbonate, sodium phosphate or ammonium hydroxide.

  20. Hyaluronidase: Purification and Inhibition by a Gold Complex and a Steroid Derivative.

    Science.gov (United States)

    1987-12-11

    isolated from rat liver, honey bee venom, and pig liver is difficult due to the different assay procedures. The marked difference in assay conditions of...for honey bee venom versus those used in the present study (0.2 M sodium phosphate buffer, pH 4.0) preclude a direct comparison of enzyme activity...21 Protein Concentration and Specific Activity 22 Purification of Hyaluronidase...........22 Sephadex G-75-120 Chromotography. ........ 23

  1. Phosphine and methylphosphine production by simulated lightning - s study for the volatile phosphorus cycle and cloud formation in the earth atmosphere

    OpenAIRE

    Glindemann, D.; Edwards, M.; Schrems, Otto

    2004-01-01

    Phosphine (PH3), was recently found worldwide even in the remote atmosphere (Naturwissenschaften 83 (1996a,131, Atmos. Environ. 37 (2003) 2429). It is of interest to find natural mechanisms which could produce phosphine gas and drive a volatile link of the atmospheric phosphorus cycle and the formation of phosphoric acid as possible condensation nuclei for clouds.Here we report on simulated lightning exposing sodium phosphate in a reducing medium (methane model atmosphere or organic matter) f...

  2. Mechanisms of Organophosphorus (OP) Injury: Sarin-Induced Hippocampal Gene Expression Changes and Pathway Perturbation

    Science.gov (United States)

    2012-01-01

    activities in frontal cortex and blood were analyzed. Frozen brain tissue were homogenized in a buffer (containing 0.1 M sodium phosphate buffer...organic anion transporter), member 8): Slc22a8 is involved in the sodium -independent transport and excretion of organic anions, some of which are...CSNK1 ( casein kinase 1) leads to its cytoplasmic retention and subsequent ubiquitination and degradation. Per1 is phosphorylated upon DNA damage

  3. pH-Responsive Layer-by-Layer Nanoshells for Direct Regulation of Cell Activity

    Science.gov (United States)

    2012-01-01

    PVPON1,300), a monomer of metharcylic acid (MAA), hydrochloric acid, sodium hydroxide, sodium chloride , monobasic sodium phosphate, and 1-ethyl-3...dimethylamino- propyl )carbodiimide hydrochloride (EDC) were purchased from Sigma-Aldrich. Initiator, 2,20-azobis(2-methylpropionitrile) (AIBN), was purchased...butoxycarbonylaminopropyl)methacrylamide (t-BOCAPMA) for synthesis of amine-functionalized PMAA, and 4.0 ( 0.2 μm silica particles as 10% aqueous suspension were

  4. Enhancing resistance to burnout via coolant chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Tu, J. P.; Dinh, T. N.; Theofanous, T. G. [Univ. of California, Santa Barbara (United States)

    2003-07-01

    Boiling Crisis (BC) on horizontal, upwards-facing copper and steel surfaces under the influence of various coolant chemistries relevant to reactor containment waters is considered. In addition to Boric Acid (BA) and TriSodium Phosphate (TSP), pure De-Ionized Water (DIW) and Tap Water (TW) are included in experiments carried out in the BETA facility. The results are related to a companion paper on the large scale ULPU facility.

  5. Elaboration and test of the method of separation of alkaline metals ions with tin phosphate

    International Nuclear Information System (INIS)

    Smirnov, G.I.; Chernyak, A.S.; Kostromina, O.N.; Kachur, N.Ya.; Shpeyzer, B.G.

    1986-01-01

    Present work is devoted to elaboration and test of the method of separation of alkaline metals ions with tin phosphate. Thus, the isotherms of sorption of lithium, sodium, potassium, rubidium and cesium ions with amorphous tin phosphate depending on their concentration, ph of solution, sorbent quantity are obtained. The parameters of extraction of potassium microquantities from sodium salts are defined. Ultra pure sodium chloride, sodium iodide, sodium sulphate, sodium nitrate, sodium nitrite, sodium phosphate are synthesized.

  6. Purification and characterization of phenoloxidase from immunized ...

    African Journals Online (AJOL)

    Aghomotsegin

    dihydroxyphenylalanine (L-DOPA) spectrophotometrically at 470 nm, according to Aso et al. (1985) with some modifications. A solution of L-DOPA (2 mg/ml) was made in a sodium phosphate buffer (SPB) (0.01 M, pH 5.9). Aliquots (20 µl) of haemolymph were diluted (v/v) in a sodium cacodylate buffer (SCB) (0.01 M sodium.

  7. Optimisation of activity and storage stability of crude pepsin ...

    African Journals Online (AJOL)

    Clearing of the extract by centrifugation at 3000g/15 min gave an extract with 902.3 PU/ml. Clarification by use of di-sodium phosphate (Na2HSO4) gave extract of 1679.1 PU/ml. The enzyme activity of the extract stored under deep freezer temperature was sibnificantly higher (p < 0.05) than ambient and refrigeration ...

  8. FY90 R&D Project Descriptions ESL (Engineering & Services Laboratory) Environics Division

    Science.gov (United States)

    1989-07-01

    nutrient demand and potential adverse reactions. Alternatives to ammonlum chloride and sodium phosphate nutrient formulas may reduce adverse side...RDX1, 2,4,6-trinltrotoluene [TNT], and l,l-dimethylhydrazine [ UDMH ]) will be dissolved or slurried in water or dissolved in an organic solvent. The...which will include measurement of NOx in the feed to the reactor and in the exhaust. Variables will include the temperature and particulate density of

  9. New technologies of chemical management in Higashi-Niigata thermal power station; Higashi niigata karyoku hatsudensho niokeru kagaku kanri no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Takeshi; Tsuchida, Hideo; Horikawa, Minoru; Takizawa, Yasushi; Sato, Tsuneo [Tohoku Electric Power Corp., Mitagi (Japan); Suzuki, Katsuyuki [COSMO Research Institute, Saitama (Japan)

    1999-01-15

    This report presents the new technologies of chemical management in Higashi-Niigata Thermal Power Station. 1. Development of New Turbine Oil with Improved Oxidation Stability We examined the effect of the dosage of DBEP as an oxidation inhibitor on oxidation stability. As a result, the newly developed turbine oil has about 30% higher oxidation stability than the conventional turbine oil. 2. Extended Interval of Chemical Cleaning for Circulation Boiler We carried out an actual plant test using the JIS guaranteed reagent (sodium phosphate) instead of the conventional chemical. As the JIS guaranteed reagent has few corrosive compounds, the corrosive rate of water-wall tubes was decreased and therefore, the interval of chemical cleaning for the circulation boiler was extended. 3. Automatic Injection Method of Sodium Phosphate for Heat Recovery Steam Generator (HRSG) of Combined Cycle Power Plant We changed the injection method of sodium phosphate from the semi automatic to automatic injection method which was controlled with the conductivity of the boiler water. In six HRSG of the combined cycle power plant, we automatically controlled phosphoric acid concentration to within the target value. (author)

  10. NCBI nr-aa BLAST: CBRC-CJAC-01-1252 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-CJAC-01-1252 ref|NP_004849.2| solute carrier family 4, sodium bicarbonate cotr...ansporter, member 8 isoform b [Homo sapiens] gb|EAW58193.1| solute carrier family 4, sodium bicarbonate cotransporter, member 8, isoform CRA_c [Homo sapiens] NP_004849.2 0.0 96% ...

  11. NCBI nr-aa BLAST: CBRC-DSIM-01-0064 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DSIM-01-0064 ref|YP_064503.1| similar to Na/dicarboxylate cotransporter [Desulfotale...a psychrophila LSv54] emb|CAG35496.1| related to Na/dicarboxylate cotransporter [Desulfotalea psychrophila LSv54] YP_064503.1 1.4 25% ...

  12. Transport of protons and lactate in cultured human fetal retinal pigment epithelial cells

    DEFF Research Database (Denmark)

    Hamann, Steffen; Cour, Morten la; Ming Lui, Ge

    2000-01-01

    Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange......Electron microscopy, intracellular pH, monocarboxylate transport, pigment epithelium of eye, proton-lactate cotransport, retinal metabolism, sodium/proton exchange...

  13. Water-transporting proteins

    DEFF Research Database (Denmark)

    Zeuthen, Thomas

    2010-01-01

    . In the K(+)/Cl(-) and the Na(+)/K(+)/2Cl(-) cotransporters, water is entirely cotransported, while water transport in glucose uniporters and Na(+)-coupled transporters of nutrients and neurotransmitters takes place by both osmosis and cotransport. The molecular mechanism behind cotransport of water...... transport. Epithelial water transport is energized by the movements of ions, but how the coupling takes place is uncertain. All epithelia can transport water uphill against an osmotic gradient, which is hard to explain by simple osmosis. Furthermore, genetic removal of aquaporins has not given support...... to osmosis as the exclusive mode of transport. Water cotransport can explain the coupling between ion and water transport, a major fraction of transepithelial water transport and uphill water transport. Aquaporins enhance water transport by utilizing osmotic gradients and cause the osmolarity...

  14. Study of a hydraulic dicalcium phosphate dihydrate/calcium oxide-based cement for dental applications.

    Science.gov (United States)

    el-Briak, Hasna; Durand, Denis; Nurit, Josiane; Munier, Sylvie; Pauvert, Bernard; Boudeville, Phillipe

    2002-01-01

    By mixing CaHPO(4) x 2H(2)O (DCPD) and CaO with water or sodium phosphate buffers as liquid phase, a calcium phosphate cement was obtained. Its physical and mechanical properties, such as compressive strength, initial and final setting times, cohesion time, dough time, swelling time, dimensional and thermal behavior, and injectability were investigated by varying different parameters such as liquid to powder (L/P) ratio (0.35-0.7 ml g(-1)), molar calcium to phosphate (Ca/P) ratio (1.67-2.5) and the pH (4, 7, and 9) and the concentration (0-1 M) of the sodium phosphate buffer. The best results were obtained with the pH 7 sodium phosphate buffer at the concentration of 0.75 M. With this liquid phase, physical and mechanical properties depended on the Ca/P and L/P ratios, varying from 3 to 11 MPa (compressive strength), 6 to 10 min (initial setting time), 11 to 15 min (final setting time), 15 to 30 min (swelling time), 7 to 20 min (time of 100% injectability). The dough or working time was over 16 min. This cement expanded during its setting (1.2-5 % according to Ca/P and L/P ratios); this would allow a tight filling. Given the mechanical and rheological properties of this new DCPD/CaO-based cement, its use as root canal sealing material can be considered as classical calcium hydroxide or ZnO/eugenol-based pastes, without or with a gutta-percha point. Copyright 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 447-453, 2002

  15. Effects of NSAIDs on the metabolism of sulphated glycosaminoglycans in healthy and (post) arthritic murine articular cartilage.

    Science.gov (United States)

    de Vries, B J; van den Berg, W B; Vitters, E; van de Putte, L B

    1988-01-01

    Several non-steroidal anti-inflammatory drugs (NSAIDs) were studied for their effects on normal and damaged murine articular cartilage, both in vitro and in vivo. In vitro, in the absence of serum, sodium salicylate caused significant suppression of 35S-glycosaminoglycan (GAG) synthesis, whereas tiaprofenic acid, piroxicam, prednisolone sodium phosphate and several other NSAIDs were without effect. Trypsin-mediated proteoglycan depletion did not change the susceptibility of the articular chondrocyte to these drugs. Similarly, no enhancement of drug effect was seen when arthritic cartilage was taken from an acutely inflamed joint, and prenisolone sodium phosphate even seemed to diminish inflammation-mediated suppression of 35S-GAG synthesis. The short term in vivo effects of some of the drugs were tested in mice with unilateral zymosan-induced arthritis. At day 1 after arthritis induction, in vivo 35S-GAG synthesis by the cartilage of the arthritic joint was decreased to 63%. Only sodium salicylate suppressed in vivo 35S-GAG synthesis in the healthy and arthritic joint to the same extent in both. At day 28, GAG synthesis in the postarthritic joint was enhanced to 160%. This type of cartilage appeared to be more susceptible to drug effects, since all drugs tested showed clear suppression of the augmented GAG production in vivo. Finally, in vivo drug effects were tested on normal and enhanced 35S-GAG degradation, the latter in the zymosan-induced arthritic joint. Both tiaprofenic acid and prednisolone sodium phosphate appeared to suppress degradation in healthy and, to some extent, in arthritic cartilage.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Hormone-Dependence of Sarin Lethality in Rats: Sex Differences and Stage of the Estrous Cycle

    Science.gov (United States)

    2015-06-12

    that causes numerous physiological events including miosis, salivation , respiratory failure, tremors, seizures, and death. Treatment regimens that...into 96-well plates. The reactions were initiated by the addition of 290 μL of 50 mM sodium phosphate buffer ( pH 8.0) containing one of the following...buffer containing 50mMHEPES pH 7.4 in a total volume of 280 μL. Treat- ed samples were loaded into a 96-microtiter plate well, and the reaction was

  17. Prevention of solids formation: Results of the FY 1999 studies

    International Nuclear Information System (INIS)

    Hunt, R.D.; Beahm, E.C.; Chase, C.W.; Collins, J.L.; Dillow, T.A.; Weber, C.F.

    1999-01-01

    Tank farm operations at Hanford and Savannah River have been adversely affected by unintentional solids formations. At Hanford, a new cross-site transfer line had to be built because nearly all the original transfer lines were no longer operational due to plugs. At Savannah River, operations at its evaporator system were suspended while a plug in the gravity drain line was physically removed at considerable expense. The plugs as Hanford and Savannah River, which have been characterized, were primarily due to sodium phosphate and sodium aluminosilicate, respectively

  18. 6. Radiopharmaceuticals

    International Nuclear Information System (INIS)

    Schiller, P.; Havranek, E.; Majer, J.

    1981-01-01

    Radionuclides commonly used in medicine are surveyed and their nuclear characteristics are presented. The methods are given of their preparation, most frequent use and detection. The list is given of radiopharmaceuticals included in the Czechoslovak Pharmacopoeia CsL 3 , ie., sodium chromate( 51 Cr), sodium iodide( 131 I), hippuran( 131 I), sodium phosphate( 32 P), colloidal gold( 198 Au), rose bengal sodium salt( 131 I), and sodium pertechnetate(sup(99m)Tc) injections. Characteristics, chemical preparation, identification tests, packaging, storage, application and dosage are shown for each preparation. Also listed are important unofficial radiopharmaceuticals, their main characteristics and data on their preparation and application. (B.S.)

  19. Dgroup: DG00093 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available DG00093 Chemical ... DGroup Prednisolone ... D00472 ... Prednisolone (JP17/USP/INN) ... D00980 ... Prednisolo...ne acetate (JP17/USP/INN) ... D00981 ... Prednisolone sodium phosphate (JP17/USP) ... D00982 ... Prednisolo...ne tebutate (JAN/USP) D01239 ... Prednisolone sodium succinate (JP17/USP) ... D01998 ... Prednisolone farnesy...late (JAN) ... D02156 ... Prednisolone hemisuccinate (USP); Prednisolone succinate (JP17) D03301 ... Prednisolo...ne valerate acetate (JAN) ... D08412 ... Prednisolone pivalate D08413 ... Prednisolone sodiu

  20. Physical and chemical factors affecting sludge consolidation

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Blimkie, M.E.; Lavoie, P.A

    1997-09-01

    Chemical reactions between sludge components and precipitation reactions within the pores of the existing sludge are shown to contribute to the consolidation of sludge under steam generator operating conditions. Simulations of sludge representative of plants with a mixed iron/copper feedtrain suggest that as the conditions in the feedtrain become more oxidizing the sludge will become harder with a higher nickel ferrite content. The precipitation of feedwater impurities introduced by condenser leaks and of zinc silicate, which is produced in plants with brass condenser tubes and silica in the makeup water, contribute significantly to sludge consolidation. Sodium phosphate is also shown to be an agent of sludge consolidation. (author)

  1. Iatrogenic Cushing's syndrome caused by intranasal steroid use.

    Science.gov (United States)

    Dursun, Fatma; Kirmizibekmez, Heves

    2017-01-01

    Cushing's syndrome (CS) is common after oral steroid use and has also been reported following topical or inhaled use, but it is extremely uncommon after intranasal administration. This is the case of a 6-year-old child who developed Cushing's syndrome after intranasal application of dexamethasone sodium phosphate for a period of 6 months. Pediatricians and other clinical practitioners should be aware that high-dose and long-term nasal steroid administration may cause iatrogenic Cushing's syndrome characterized by complications of glucocorticoid excess as well as serious and even life-threatening complications of adrenal insufficiency.

  2. Albumin binding of anti-inflammatory drugs. Utility of a site-oriented versus a stoichiometric analysis

    DEFF Research Database (Denmark)

    Honoré, B; Brodersen, R

    1984-01-01

    Binding equilibria of 12 nonsteroidal, anti-inflammatory substances, salicylic acid, diflunisal, phenylbutazone, azapropazone, fenbufen, biphenylacetic acid, naproxen, flurbiprofen, ibuprofin, diclofenac, indomethacin, and benoxaprofen, to defatted human serum albumin has been investigated at 37...... degrees, pH 7.4, in a sodium phosphate buffer, 66 mM, by means of equilibrium dialysis and, in case of salicylic acid, by dialysis rate determinations. Cobinding of each of these drugs with monoacetyl-4,4'-diaminodiphenyl sulfone, warfarin, and diazepam has been studied by measuring dialysis rates...

  3. Water chemistry related problems in captive power plant of Heavy Water Plant [Manuguru

    International Nuclear Information System (INIS)

    Prasada Rao, G.; Mohapatra, C.

    2000-01-01

    This study is intended to improve the power generating capacity of Turbo Generator-3 in CPP. It was observed that steam flow through TG-3 was not as per rated; however there were no abnormal vibrations. After stopping and opening the turbine, deposits were found on turbine blade. Turbine blade scales were analysed for all the stages, HP, middle, LP, casings. Boiler drum water, feed water, DM water, filter water chemistry were studied. LP blade scale mainly consists of silica, whereas HP blade scale consists of iron oxide, sodium phosphate, silica etc. It was concluded that less generating capacity of power was because of scaling on turbine blade. (author)

  4. 78 FR 67364 - Endocrinologic and Metabolic Drugs Advisory Committee; Notice of Meeting

    Science.gov (United States)

    2013-11-12

    ...-glucose cotransporter 2 inhibitor developed as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. FDA intends to make background material available to the...

  5. Characterization and corrosion behavior of ceramic coating on magnesium by micro-arc oxidation

    International Nuclear Information System (INIS)

    Durdu, Salih; Aytac, Aylin; Usta, Metin

    2011-01-01

    Highlights: · The commercial pure magnesium was coated by micro-arc oxidation method. · The coating is composed of two layers, a porous outer layer and a dense inner layer. · A super corrosion resistance was achieved with MAO coatings. · Coating with Mg 2 SiO 4 is more resistant to corrosion than that containing Mg 3 (PO 4 ) 2 . - Abstract: In this study, the commercial pure magnesium was coated in different aqueous solutions of Na 2 SiO 3 and Na 3 PO 4 by the micro-arc oxidation method (MAO). Coating thickness, phase composition, surface and cross sectional morphology and corrosion resistance of coatings were analyzed by eddy current method, X-ray diffraction (XRD), scanning electron microscope (SEM) and tafel extrapolation method, respectively. The average thickness of the coatings ranged from 52 to 74 μm for sodium silicate solution and from 64 to 88 μm for sodium phosphate solution. The dominant phases on the coatings were detected as spinal Mg 2 SiO 4 (Forsterite) and MgO (Periclase) for sodium silicate solution and Mg 3 (PO 4 ) 2 (Farringtonite) and MgO (Periclase) for sodium phosphate solution. SEM images reveal that the coating is composed of two layers as of a porous outer layer and a dense inner layer. The corrosion results show the coating consisting Mg 2 SiO 4 is more resistant to corrosion than that containing Mg 3 (PO 4 ) 2 .

  6. Improved Yield of High Molecular Weight DNA Coincides with Increased Microbial Diversity Access from Iron Oxide Cemented Sub-Surface Clay Environments

    Science.gov (United States)

    Hurt, Richard A.; Robeson, Michael S.; Shakya, Migun; Moberly, James G.; Vishnivetskaya, Tatiana A.; Gu, Baohua; Elias, Dwayne A.

    2014-01-01

    Despite over three decades of progress, extraction of high molecular weight (HMW) DNA from high clay soils or iron oxide cemented clay has remained challenging. HMW DNA is desirable for next generation sequencing as it yields the most comprehensive coverage. Several DNA extraction procedures were compared from samples that exhibit strong nucleic acid adsorption. pH manipulation or use of alternative ion solutions offered no improvement in nucleic acid recovery. Lysis by liquid N2 grinding in concentrated guanidine followed by concentrated sodium phosphate extraction supported HMW DNA recovery from clays high in iron oxides. DNA recovered using 1 M sodium phosphate buffer (PB) as a competitive desorptive wash was 15.22±2.33 µg DNA/g clay, with most DNA consisting of >20 Kb fragments, compared to 2.46±0.25 µg DNA/g clay with the Powerlyzer system (MoBio). Increasing PB concentration in the lysis reagent coincided with increasing DNA fragment length during initial extraction. Rarefaction plots of 16S rRNA (V1–V3 region) pyrosequencing from A-horizon and clay soils showed an ∼80% and ∼400% larger accessed diversity compared to the Powerlyzer soil DNA system, respectively. The observed diversity from the Firmicutes showed the strongest increase with >3-fold more operational taxonomic units (OTU) recovered. PMID:25033199

  7. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

  8. Electrocatalytic hydrogen evolution under densely buffered neutral pH conditions

    KAUST Repository

    Shinagawa, Tatsuya

    2015-08-18

    Under buffered neutral pH conditions, solute concentrations drastically influence the hydrogen evolution reaction (HER). The iR-free HER performance as a function of solute concentration was found to exhibit a volcano-shaped trend in sodium phosphate solution at pH 5, with the maximum occurring at 2 M. A detailed microkinetic model that includes calculated activity coefficients, solution resistance, and mass-transport parameters accurately describes the measured values, clarifying that the overall HER performance is predominantly governed by mass-transport of slow phosphate ions (weak acid). In the HER at the optimum concentration of approximately 2 M sodium phosphate at pH 5, our theoretical model predicts that the concentration overpotential accounts for more than half of the required overpotential. The substantial concentration overpotential would originate from the electrolyte property, suggesting that the proper electrolyte engineering will result in an improved apparent HER performances. The significance of concentration overpotential shown in the study is critical in the advancement of electrocatalysis, biocatalysis, and photocatalysis.

  9. Reduction of Saltiness and Acrylamide Levels in Palm Sugar-Like Flavouring through Buffer Modification and the Addition of Calcium Chloride

    Directory of Open Access Journals (Sweden)

    Wan Aida Wan Mustapha

    2013-06-01

    Full Text Available Palm sugar-like flavouring (PSLF is a type of flavour product that is formed by heating amino acids and sugar under specific heating conditions. Unfortunately, PSLF has a salty taste and contains high amounts of acrylamide. Hence, the objective of this research was to reduce saltiness and acrylamide without negatively affecting the aroma properties of PSLF. A decrease in the sodium phosphate (NaHPO4 buffer concentration from 0.20 to 0.02 M was found to reduce sodium to approximately 15% of the level found in original PSLF. A further decrease (~25% in the sodium content was achieved by removing monobasic sodium phosphate (NaH2PO4 from the buffer system. Meanwhile, the addition of CaCl2 at 20–40 mg/L reduced the acrylamide content in PSLF by as much as 58%. A CaCl2 concentration of 20 mg/mL was most favourable as it most efficiently suppressed acrylamide formation while providing an acceptably high flavour yield in PSLF. In view of the high acrylamide content in PSLF, additional work is necessary to further reduce the amount of acrylamide by controlling the asparagine concentration in the precursor mixture.

  10. Reduction of saltiness and acrylamide levels in palm sugar-like flavouring through buffer modification and the addition of calcium chloride.

    Science.gov (United States)

    Tan, Phui Yee; Tan, Chin Ping; Abas, Faridah; Ho, Chun Wai; Mustapha, Wan Aida Wan

    2013-06-10

    Palm sugar-like flavouring (PSLF) is a type of flavour product that is formed by heating amino acids and sugar under specific heating conditions. Unfortunately, PSLF has a salty taste and contains high amounts of acrylamide. Hence, the objective of this research was to reduce saltiness and acrylamide without negatively affecting the aroma properties of PSLF. A decrease in the sodium phosphate (NaHPO₄) buffer concentration from 0.20 to 0.02 M was found to reduce sodium to approximately 15% of the level found in original PSLF. A further decrease (~25%) in the sodium content was achieved by removing monobasic sodium phosphate (NaH₂PO₄) from the buffer system. Meanwhile, the addition of CaCl₂ at 20-40 mg/L reduced the acrylamide content in PSLF by as much as 58%. A CaCl₂ concentration of 20 mg/mL was most favourable as it most efficiently suppressed acrylamide formation while providing an acceptably high flavour yield in PSLF. In view of the high acrylamide content in PSLF, additional work is necessary to further reduce the amount of acrylamide by controlling the asparagine concentration in the precursor mixture.

  11. Experimental investigation of material chemical effects on emergency core cooling pump suction filter performance after loss of coolant accident

    International Nuclear Information System (INIS)

    Park, Jong Woon; Park, Byung Gi; Kim, Chang Hyun

    2009-01-01

    Integral tests of head loss through an emergency core cooling filter screen are conducted, simulating reactor building environmental conditions for 30 days after a loss of coolant accident. A test rig with five individual loops each of whose chamber is established to test chemical product formation and measure the head loss through a sample filter. The screen area at each chamber and the amounts of reactor building materials are scaled down according to specific plant condition. A series of tests have been performed to investigate the effects of calcium-silicate, reactor building spray, existence of calcium-silicate with tri-sodium phosphate (TSP), and composition of materials. The results showed that head loss across the chemical bed with even a small amount of calcium-silicate insulation instantaneously increased as soon as TSP was added to the test solution. Also, the head loss across the filter screen is strongly affected by spray duration and the head loss increase is rapid at the early stage, because of high dissolution and precipitation of aluminum and zinc. After passivation of aluminum and zinc by corrosion, the head loss increase is much slowed down and is mainly induced by materials such as calcium, silicon, and magnesium leached from NUKON TM and concrete. Furthermore, it is newly found that the spay buffer agent, tri-sodium phosphate, to form protective coating on the aluminum surface and reduce aluminum leaching is not effective for a large amount of aluminum and a long spray.

  12. On the radiolysis of desoxyribonucleic acid in presence of serum albumin

    International Nuclear Information System (INIS)

    Geiger, A.M.

    1984-01-01

    The experiments were carried out on the simple model of DNA-bovine serum albumin. The two substances were solved in 10 -2 M sodium phosphate buffer pH 7 in the ratio 1 : 10, which is about the natural ratio of nucleic acid to protein in the cell. The preparations were irradiated with various doses up to 1760 Gy, in the presence of air, nitrogen, or laughing gas. The irradiated samples were then separated over the gel sepharose CL-2B using 2 x 10 -2 M sodium phosphate buffer pH 7 with and without sodium dodecyl sulphate. Photometric measurement of the fractions was done using a wavelength of 260 nm. The protein content was determined with two different colorimetric techniques, after calibrating experiments defining the linear range. In order to determine the effect of the protein on the radiosensitivity of the DNA, samples without bovine serum albumin were irradiated in the three gaseous environments with 440 Gy. Incubation of the irradiated samples with SDS, and separation in the presence of SDS, revealed information on the covalent bonds forming between DNA and bovine serum albumin, whereas gel filtration without SDS yielded information also on non-covalent bonds. (orig./EF) [de

  13. Magnetic properties of bioactive glass-ceramics containing nanocrystalline zinc ferrite

    International Nuclear Information System (INIS)

    Singh, Rajendra Kumar; Srinivasan, A.

    2011-01-01

    Glass-ceramics with finely dispersed zinc ferrite (ZnFe 2 O 4 ) nanocrystallites were obtained by heat treatment of x(ZnO,Fe 2 O 3 )(65-x)SiO 2 20(CaO,P 2 O 5 )15Na 2 O (6≤x≤21 mole%) glasses. X-ray diffraction patterns of the glass-ceramic samples revealed the presence of calcium sodium phosphate [NaCaPO 4 ] and zinc ferrite [ZnFe 2 O 4 ] as major crystalline phases. Zinc ferrite present in nanocrystalline form contributes to the magnetic properties of the glass-ceramic samples. Magnetic hysteresis cycles of the glass-ceramic samples were obtained with applied magnetic field sweeps of ±20 kOe and ±500 Oe, in order to evaluate the potential of these glass-ceramics for hyperthermia treatment of cancer. The evolution of magnetic properties in these samples, viz., from a partially paramagnetic to fully ferrimagnetic nature has been explored using magnetometry and X-ray diffraction studies. - Research highlights: → The glass-ceramics contain bone mineral and magnetic phases. → Calcium sodium phosphate and zinc ferrite nanocrystallites have been identified in all the sample. → With an increase in ZnO and Fe2O3 content, magnetic property of samples evolved from partially paramagnetic to fully ferrimagnetic nature. → Large magnetic hysteresis loops have been obtained for samples with high ZnO+Fe2O3 content.

  14. Purification of a-galactosidase from seeds of Sesbania marginata

    Directory of Open Access Journals (Sweden)

    Falco A.L.P.

    2000-01-01

    Full Text Available Alpha-galactosidase taken from a raw extract of Sesbania marginata legume seeds was purified by partitioning in aqueous two-phase systems (ATPS. Initially, galactomannan/dextran 2,000,000 systems were used for the purification, and the partition coefficients of alpha -galactosidase varied from 1.5 to 4.0. However, mass transport in these systems was poor due to the high viscosity of the employed polymers. Therefore, partitioning in polyethyleneglycol (PEG/ sodium phosphate systems and the effect of sodium chloride upon the enzyme purification and the yield of alpha -galactosidase were also investigated. The purification achieved in a single-step was 5.7 with a recovery of 144% of alpha -galactosidase, possibly due to the removal of materials which inhibited alpha -galactosidase activity before the purification. The removal of the main protein contaminants and the highest yields were achieved in PEG 4,000/ sodium phosphate + 6% NaCl system at pH 5.0. Further purification by preparative on-exchange chromatography was also developed.

  15. An improved method to prepare an injectable microemulsion of the galanin-receptor 3 selective antagonist, SNAP 37889, using Kolliphor® HS 15

    Science.gov (United States)

    Scheller, Karlene J.; Williams, Spencer J.; Lawrence, Andrew J.; Jarrott, Bevyn; Djouma, Elvan

    2014-01-01

    Research into the galanin-3 (GAL3) receptor has many challenges, including the lack of commercially available selective ligands. While the identification of non-peptidergic GAL3 receptor-selective antagonists, 1-phenyl-3-[3-(trifluoromethyl)phenyl]iminoindol-2-one (SNAP 37889) and 1-[3-(2-pyrrolidin-1-ylethoxy)phenyl]-3-[3-(trifluoromethyl)phenyl]iminoindol-2-one (SNAP 398299) have implicated a role for GAL3 receptors in anxiety, depression and drug-seeking behaviour, a major limitation of their use is poor aqueous solubility. Previously we have used 5% dimethylsulfoxide (DMSO) with 1% hydroxypropylmethyl cellulose in saline to dissolve SNAP 37889 for intraperitoneal (i.p.) injections of rats; however this produced a micro-suspension that was not ideal. The injectable formulation of SNAP 37889 was improved as follows:•30% (w/v) Kolliphor® HS 15 (Solutol HS® 15) and sodium phosphate buffer (0.01 M, pH 7.4) were used as vehicles.•A smooth glass mortar and pestle was used to triturate the Kolliphor® HS 15 and SNAP 37889 into a paste before addition to the sodium phosphate buffer at room temperature (RT).•The resulting mixture was vortexed until the paste was fully dissolved and the microemulsion was allowed to sit for 20 min to allow air bubbles to coalesce. PMID:26150955

  16. Estimated inventory of chemicals added to underground waste tanks, 1944--1975

    International Nuclear Information System (INIS)

    Allen, G.K.

    1976-03-01

    The five major chemical processes, the Bismuth Phosphate process, the Uranium Recovery process, the Redox process, the Purex process, and the Waste Fractionization process have each contributed to give the total Hanford waste chemicals. Each of these processes is studied to determine the total estimated chemicals stored in underground waste tanks. The chemical contents are derived mainly from flowsheet compositions and recorded waste volumes sent to underground storage. The major components and amounts of Hanford waste are sodium hydroxide, 230 million gram-moles (20 million pounds), sodium nitrate, 1400 million gram-moles (270 million pounds), sodium nitrite, 220 million gram-moles (34 million pounds), sodium aluminate, 400 million gram-moles (72 million pounds), and sodium phosphate, 87 million gram-moles (31 million pounds). Chemical analyses of the sludge and salt cake samples are tabulated to determine the chemical characteristics of the solids. A relative chemical toxicity of the Hanford underground waste tank chemicals is developed from maximum permissible chemical concentrations in air and water. The most toxic chemicals are assumed to be sodium phosphate--35%, sodium aluminate--28%, and chromium hydroxide--19%. If air standards set toxicity limits, the most toxic chemicals are bismuth--41%, chromium hydroxide--23%, and fluoride--10%

  17. Effects of phosphate environments on turbine materials: preliminary results

    International Nuclear Information System (INIS)

    Chen, M.C.; Shalvoy, R.S.; Gould, G.C.

    1985-01-01

    Stress corrosion cracking (SCC) is a serious hazard to large steam turbines. In many cases, this cracking is thought caused by concentrated deposits of caustics or chlorides, formed from the steam by concentrating mechanisms. To minimize the likelihood of forming these corrosive deposits, turbine manufacturers recommend that the levels of contaminants in the steam be maintained at low levels. The steam purity needed to prevent the formation of corrosive deposits is at present uncertain. As an aid in judging the steam purity needed to avoid corrosive deposits, the General Electric Company surveyed the utility industry to determine current feedwater practices, the levels of steam purity attained, and the nature of the corrosion problems encountered. One hypothesis to explain the lower corrosivity of steam from drum boilers concerns the sodium phosphate to compounds commonly added to drum boiler water for pH control. To test this hypothesis, the present program was undertaken to study the effect of sodium phosphate on the corrosivity of the two most common corrosive turbine deposits, sodium chloride and sodium hydroxide. Four turbine materials - a rotor steel, a disc steel, and two turbine blade steels - were chosen for this study. The results from the first half of a two-year project are described. So far the corrosivity of the deposits without phosphate has been determined. Work to determine the corrosivity of deposits with phosphate is presently under way and only the electrochemical test results are discussed

  18. Preparation of molecularly imprinted polymers for strychnine by precipitation polymerization and multistep swelling and polymerization and their application for the selective extraction of strychnine from nux-vomica extract powder.

    Science.gov (United States)

    Nakamura, Yukari; Matsunaga, Hisami; Haginaka, Jun

    2016-04-01

    Monodisperse molecularly imprinted polymers for strychnine were prepared by precipitation polymerization and multistep swelling and polymerization, respectively. In precipitation polymerization, methacrylic acid and divinylbenzene were used as a functional monomer and crosslinker, respectively, while in multistep swelling and polymerization, methacrylic acid and ethylene glycol dimethacrylate were used as a functional monomer and crosslinker, respectively. The retention and molecular recognition properties of the molecularly imprinted polymers prepared by both methods for strychnine were evaluated using a mixture of sodium phosphate buffer and acetonitrile as a mobile phase by liquid chromatography. In addition to shape recognition, ionic and hydrophobic interactions could affect the retention of strychnine in low acetonitrile content. Furthermore, molecularly imprinted polymers prepared by both methods could selectively recognize strychnine among solutes tested. The retention factors and imprinting factors of strychnine on the molecularly imprinted polymer prepared by precipitation polymerization were 220 and 58, respectively, using 20 mM sodium phosphate buffer (pH 6.0)/acetonitrile (50:50, v/v) as a mobile phase, and those on the molecularly imprinted polymer prepared by multistep swelling and polymerization were 73 and 4.5. These results indicate that precipitation polymerization is suitable for the preparation of a molecularly imprinted polymer for strychnine. Furthermore, the molecularly imprinted polymer could be successfully applied for selective extraction of strychnine in nux-vomica extract powder. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Evaluation of in vitro effects of some analgesic drugs on erythrocyte and recombinant carbonic anhydrase I and II.

    Science.gov (United States)

    Gökçe, Başak; Gençer, Nahit; Arslan, Oktay; Turkoğlu, Sumeyye Aydogan; Alper, Meltem; Köçkar, Feray

    2012-02-01

    The in vitro effects of the injectable form of analgesic drugs, dexketoprofen trometamol, dexamethasone sodium phosphate, metamizole sodium, diclofenac sodium, thiocolchicoside, on the activity of purified human carbonic anhydrase I and II were evaluated. The effect of these drugs on erythrocyte hCA I and hCA II was compared to recombinant hCA I and hCA II expressed in Ecoli. IC(50) values of the drugs that caused inhibition were determined by means of activity percentage diagrams. The IC(50) concentrations of dexketoprofen trometamol and dexamethasone sodium phosphate on hCA I were 683 μM and 4250 μM and for hCA II 950 μM and 6200 μM respectively. Conversely, the enzyme activity was increased by diflofenac sodium. In addition, thiocolchicoside has not any affect on hCA I and hCA II. The effect of these drugs on erythrocyte hCA I and hCA II were consistent with the inhibition of recombinant enzymes.

  20. Electrocatalytic hydrogen evolution under densely buffered neutral pH conditions

    KAUST Repository

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-01-01

    Under buffered neutral pH conditions, solute concentrations drastically influence the hydrogen evolution reaction (HER). The iR-free HER performance as a function of solute concentration was found to exhibit a volcano-shaped trend in sodium phosphate solution at pH 5, with the maximum occurring at 2 M. A detailed microkinetic model that includes calculated activity coefficients, solution resistance, and mass-transport parameters accurately describes the measured values, clarifying that the overall HER performance is predominantly governed by mass-transport of slow phosphate ions (weak acid). In the HER at the optimum concentration of approximately 2 M sodium phosphate at pH 5, our theoretical model predicts that the concentration overpotential accounts for more than half of the required overpotential. The substantial concentration overpotential would originate from the electrolyte property, suggesting that the proper electrolyte engineering will result in an improved apparent HER performances. The significance of concentration overpotential shown in the study is critical in the advancement of electrocatalysis, biocatalysis, and photocatalysis.

  1. Cation-Coupled Bicarbonate Transporters

    OpenAIRE

    Aalkjaer, Christian; Boedtkjer, Ebbe; Choi, Inyeong; Lee, Soojung

    2014-01-01

    Cation-coupled HCO3− transport was initially identified in the mid-1970s when pioneering studies showed that acid extrusion from cells is stimulated by CO2/HCO3− and associated with Na+ and Cl− movement. The first Na+-coupled bicarbonate transporter (NCBT) was expression-cloned in the late 1990s. There are currently five mammalian NCBTs in the SLC4-family: the electrogenic Na,HCO3-cotransporters NBCe1 and NBCe2 (SLC4A4 and SLC4A5 gene products); the electroneutral Na,HCO3-cotransporter NBCn1 ...

  2. The net acid extruders NHE1, NBCn1 and MCT4 promote mammary tumor growth through distinct but overlapping mechanisms

    DEFF Research Database (Denmark)

    Andersen, Anne Poder; Samsøe-Petersen, Jacob; Oernbo, Eva Kjer

    2018-01-01

    High metabolic and proliferative rates in cancer cells lead to production of large amounts of H+ and CO2 , and as a result, net acid extruding transporters are essential for the function and survival of cancer cells. We assessed protein expression of the Na+ /H+ exchanger NHE1, the Na+ - HCO3......- cotransporter NBCn1, and the lactate-H+ cotransporters MCT1 and -4 by immunohistochemical analysis of a large cohort of breast cancer samples. We found robust expression of these transporters in 20, 10, 4 and 11% of samples, respectively. NHE1 and NBCn1 expression both correlated positively with progesterone...

  3. Simple method of determining induced 32P activity following burning of sulfur tablets by measuring Cherenkov radiation

    International Nuclear Information System (INIS)

    Kubicek, I.

    1986-01-01

    A method is described allowing the detemination of induced beta activity of phosphorus-32 using Cherenkov radiation, following the burning of sulfur tablets in the measuring vesels. A mixture of phosphoric acid and sodium phosphate solutions was used as the medium for the production of Cherenkov radiation. The losses of activity during sulfur tablet burning, the detection efficiency and the minimum detectable activity for which the minimum determinable dose was estimated, were determined. The results obtained by measurement with Cherenkov radiation are compared with other techniques of phosphorus-32 detection. The method was tested at VUPL Bratislava on detectors irradited using a 252 Cf fast neutron source. From Caswell's data, the fluence-to-kerma conversin factor was determined for a neutron spectrum calculated by the Monte Carlo method. Tissue kerma was estimated from the neutron fluence corresponding to the appropriate values of saturated activity per 1 sulfur-32 nucleus. (author)

  4. Identification of crystals in Hanford nuclear waste using polarized light microscopy

    International Nuclear Information System (INIS)

    Herting, D.L.

    1984-09-01

    The use of polarized light microscopy for identifying crystals encountered in Rockwell Hanford Operations chemical studies is described. Identifying characteristics and full-color photographs are presented for crystals commonly found in Hanford Site nuclear waste, including sodium nitrate, sodium nitrite, sodium aluminate, sodium phosphate, sodium fluoride, ammonium heptafluorozirconate, sodium sulfate, sodium carbonate, and ammonium nitrate. These characteristics are described in terms of birefringence, extinction position, interference figure, sign of elongation, optic sign, and crystal morphology. Background information on crystal optics is presented so that these traits can be understood by the nonmicroscopist. Detailed operational instructions are given so that the novice microscope user can make the proper adjustments of the instrument to search for and observe the identifying features of the crystals

  5. Mixed phosphates of the Na3PO4 - LnPO4 systems

    International Nuclear Information System (INIS)

    Slivko, T.A.; Smirnova, I.N.; Zimina, G.V.; Spiridonov, F.M.; Chudinova, N.N.

    2002-01-01

    The phase relationships in the systems Na 3 PO 4 - LnPO 4 (subsolidus 950 Deg C cross-sections), where Ln=Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, were studied by X-ray analysis. Reactions of the components were deduced, formed phases were separated and identified. The Na 6 Ln 3 (PO 4 ) 5 (Ln=Dy, Ho, Tm), Na 3 Ln 2 (PO 4 ) 3 (Ln=Tm, Yb, Lu) compounds and phases of the unstable composition Na 6+x Ln 3-x/3 (PO 4 ) 5 (Ln=Yb, Lu, 0 ≤ x ≤ 1.5) were detected for the first time. In all systems the existence of the Na 3-x Ln x/3 PO 4 unstable composition phase on the basis of the high temperature modification of sodium phosphate (sp. gr. Fm3m) is established, suggesting that stabilization of this modification by rare earth ions is possible [ru

  6. Detection of carrier heterogeneity by rate of ligand dialysis: medium-chain fatty acid interaction with human serum albumin and competition with chloride

    DEFF Research Database (Denmark)

    Honoré, B; Brodersen, R

    1988-01-01

    Binding equilibria for decanoate, octanoate, and hexanoate to defatted human serum albumin were investigated by dialysis exchange rate determinations in 66 mM sodium phosphate buffer, pH 7.4, 37 degrees C. The binding isotherms for decanoate and octanoate could not be fitted by the general binding......(5) M-1, respectively, for decanoate; 1.6 X 10(6) and 3.5 X 10(4) for octanoate; and 7.1 X 10(4) and 8.0 X 10(2) M-1 for hexanoate. The high-affinity albumin component binds 1 mol decanoate, 1 mol octanoate, or 2 mol hexanoate more than is bound to the low-affinity component. Chloride ions compete...

  7. Standardization of NaI gamma spectrometer using a newly developed standard for the estimation of 228Ra in rare earth chloride solution

    International Nuclear Information System (INIS)

    Sahu, A.; Patra, R.P.; Jha, S.K.; Tripathi, R.M.; Patro, P.

    2018-01-01

    Monazite is a naturally occurring mineral which is a phosphate of various rare earths and thorium with traces of uranium. Indian Rare Earths Limited has set up a Monazite Processing Plant (MoPP) at Orissa Sand Complex (OSCOM), Odisha for recovery of various elements from Monazite. The finely ground monazite is processed with hot NaOH to separate the phosphate component as Tri-Sodium Phosphate from the mixed hydroxide. Then the mixed hydroxide is treated with HCl at controlled pH to separate rare earth as rare earth chloride solution. The rare earth chloride solution also contains 228 Ra which is generated in the 232 Th decay series. The rare earth chloride solution is then treated with BaCl 2 , MgSO 4 and Na 2 S; 228 Ra gets co-precipitated with Ba as Lead-Barium Sulfate. To meet the regulatory requirement, 228 Ra activity is reduced to below 1 Bq/g limit

  8. Effect of phytase in laying hen diets with different phosphorus sources

    Directory of Open Access Journals (Sweden)

    EM Casartelli

    2005-06-01

    Full Text Available An experiment was conducted to evaluate the effects of the enzyme phytase in diets formulated with different phosphorus sources on performance, eggshell quality and excretion of commercial laying hens. Two hundred and eighty-eight commercial Hyssex Brown laying hens were evaluated during two production phases, which included eight twenty-eight-day cycles, using a completely randomized design in a 3x2 factorial with six replicates of eight birds per treatment. Three phosphorus sources (calcium and sodium phosphate, micro-granulated dicalcium phosphate and triple super phosphate and two phytase levels (0 or 1000 FTU/kg diet were tested in the composition of the diets. After the post-peak period, triple super phosphate decreased bird performance and eggshell quality. It was possible to reduce the levels of phosphorus supplementation when phytase was added to the diet. Besides, phytase supplementation reduced phosphorus, calcium and nitrogen excretions, but affected mean egg weight at production peak.

  9. Preparation of Trivalent Chromium and Rare Earth Composite Conversion Coating on Aluminum Alloy Surface

    Science.gov (United States)

    Huang, Jianzhen

    2018-01-01

    In this paper, the surface conversion film on 6063 aluminum alloy was prepared by chemical plating process with chromium sulfate, lanthanum sulfate and sodium phosphate as film forming agent. The corrosion resistance and surface morphology of the conversion film were analyzed by pitting corrosion test of copper sulfate and SEM. The results show that when Cr2(SO4)3 is 10 g/L, La2(SO4)3 is 2 g/L, Na3PO4 is 8 g/L, pH value is 3, temperature is 40 °C, reaction time is 10 min, the corrosion resistance of the surface conversion film is the best. The conversion coating is light green, composed of Cr, La, P, Al, O and other elements.

  10. Polymeric compositions for “dry” decontamination of NPP equipment and premises

    International Nuclear Information System (INIS)

    Voronik, N.I.; Toropova, V.V.

    2015-01-01

    In JIPNR – “Sosny” NASB developed decontaminating polymeric compositions based on binder – polyvinyl alcohol solution with active additives such as nitric and borohydrofluoric acids, 1-hydroxyethylidene diphosphonic acid and its salts, detergents and fillers - natural tripoli; tripoli modified by ferrocyanides of nickel and copper; pulverized dolomite modified by manganese oxides, ferrocyanides of nickel and copper; clinoptilolite modified by iron chlorides (III) and calcium sodium phosphate and potassium ferrocyanide; hydrolytic lignin. It is shown that the developed decontaminating polymeric compositions (pastes) possess high decontaminating capacity (FD 102 – 103) and low adhesion to the surfaces of stainless and carbon steels, including painted, plastic, self-leveling floors, teflon-surface. Prolonged leaching method allowed determine the chemical resistance of “dry” decontamination wastes, strength of "1"3"7Cs and "6"0Co fixations in wastes obtained in result of using new decontamination pastes [ru

  11. The influence of p H during growth of bacteria in toluene

    International Nuclear Information System (INIS)

    Nahar, N.; Quilty, B.; Alauddin, M.

    2000-01-01

    Five toluene tolerant species were isolated from the activated sludge of a wastewater treatment plant (Dublin). The isolate were investigated for influence of pH on the growth in toluene. Four of the bacteria have been identified as Pseudomonas putida and one as an Aeromonas caviae. When these bacteria were grown with toluene as the sole source of carbon and energy, the pH of the culture medium became acidic and dropped. 0.5 M sodium phosphate buffer was selected to investigate the optimum pH for growth in the presence of 500 mu l of toluene. In general, the growth was optimum between pH 5.8 and 7.4. (author)

  12. Development of cement material using inorganic additives

    International Nuclear Information System (INIS)

    Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

    1997-01-01

    Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

  13. Evaluation of the Effects of Lime-bassanite-charcoal Amendment on the Immobilization of Cadmium in Contaminated Soil.

    Science.gov (United States)

    Huang, Shunhong; Yang, Yi; Li, Qian; Su, Zhen; Yuan, Cuiyu; Ouyang, Kun

    2017-03-01

    The effects of amendments, such as lime, bassanite, sodium phosphate, steel slag and charcoal, and their compounds on the immobilization of cadmium (Cd) are investigated. The lime-bassanite-charcoal compound shows the best remediation performance compared to other agents in conducted experiments. The optimum condition for lime-bassanite-charcoal application in contaminated soil is lime-bassanite-charcoal with a mass ratio of 1:1/3:2/3, a dose of 2% of the soil weight, and a liquid-to-solid ratio of 35%-40%; additionally, the agents should be added before water addition. The highest Cd removal rate was 58.94% (±1.19%) with a ∆pH of 0.23, which is much higher than the rates reported in previous studies. The compound amendment was used in a field experiment, demonstrating a Cd removal efficiency of 48.78% (±4.23), further confirming its effectiveness.

  14. Tri-potassium phosphate as a solid catalyst for biodiesel production from waste cooking oil

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Guoqing; Kusakabe, Katsuki; Yamasaki, Satoko [Department of Living Environmental Science, Fukuoka Women' s University, 1-1-1 Kasumigaoka, Higashi-ku, Fukuoka 813-8529 (Japan)

    2009-04-15

    Transesterification of waste cooking oil with methanol, using tri-potassium phosphate as a solid catalyst, was investigated. Tri-potassium phosphate shows high catalytic properties for the transesterification reaction, compared to CaO and tri-sodium phosphate. Transesterification of waste cooking oil required approximately two times more solid catalyst than transesterification of sunflower oil. The fatty acid methyl ester (FAME) yield reached 97.3% when the transesterification was performed with a catalyst concentration of 4 wt.% at 60 C for 120 min. After regeneration of the used catalyst with aqueous KOH solution, the FAME yield recovered to 88%. Addition of a co-solvent changed the reaction state from three-phase to two-phase, but reduced the FAME yield, contrary to the results with homogeneous catalysts. The catalyst particles were easily agglomerated by the glycerol drops derived from the homogeneous liquid in the presence of co-solvents, reducing the catalytic activity. (author)

  15. Gibbs free energy of transfer of a methylene group on {UCON + (sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

    International Nuclear Information System (INIS)

    Silverio, Sara C.; Rodriguez, Oscar; Teixeira, Jose A.; Macedo, Eugenia A.

    2010-01-01

    The Gibbs free energy of transfer of a suitable hydrophobic probe can be regarded as a measure of the relative hydrophobicity of the different phases. The methylene group (CH 2 ) can be considered hydrophobic, and thus be a suitable probe for hydrophobicity. In this work, the partition coefficients of a series of five dinitrophenylated-amino acids were experimentally determined, at 23 o C, in three different tie-lines of the biphasic systems: (UCON + K 2 HPO 4 ), (UCON + potassium phosphate buffer, pH 7), (UCON + KH 2 PO 4 ), (UCON + Na 2 HPO 4 ), (UCON + sodium phosphate buffer, pH 7), and (UCON + NaH 2 PO 4 ). The Gibbs free energy of transfer of CH 2 units were calculated from the partition coefficients and used to compare the relative hydrophobicity of the equilibrium phases. The largest relative hydrophobicity was found for the ATPS formed by dihydrogen phosphate salts.

  16. UV-visible, Raman and E.S.R. studies of gamma-irradiated NiO-doped sodium metaphosphate glasses.

    Science.gov (United States)

    ElBatal, Fatma H; Morsi, Reham M; Ouis, Mona A; Marzouk, Samir Y

    2010-11-01

    UV-visible spectroscopic measurements of Ni-doped sodium phosphate glasses were carried out before and after successive gamma irradiation. The undoped glass reveals strong UV absorption originating from trace iron impurities. NiO-doped glasses show characteristic absorption bands due mainly to octahedral coordination of Ni(2+) ions. Gamma irradiation produces induced bands generated from intrinsic defects and extrinsic defects. The changes in the spectroscopic data are discussed in relation to the structural evolution caused by the changes in composition and coordination state of nickel ions. The change in the growth behaviour of the induced bands is related to the annihilation or approach saturation of these characteristic induced bands. Raman and E.S.R. spectroscopic measurements confirm the presence of nickel as Ni(2+) ions in octahedral state. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. IBD medications during pregnancy and lactation

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Maxwell, Cynthia; Hendel, Jakob

    2013-01-01

    pregnancy and breast-feeding, alternatives to ciprofloxacin, natalizumab and sodium phosphate should also be considered for pregnant women. Breast-feeding is also discouraged while on treatment with ciclosporin, metronidazole and ciprofloxacin. However, therapy with 5-aminosalicylic acid preparations......IBD often affects patients during their peak reproductive years. Several drugs are available for the treatment of IBD and new drugs are continuously in the pipeline. As long-term administration of medications is often necessary, the safety of drug therapy during pregnancy and breast-feeding needs...... to be considered in daily clinical practice. The aim of this Review is to summarize the latest information concerning the safety of medications used to treat IBD during pregnancy and lactation, as well as their effect on fertility. Although only thalidomide and methotrexate are absolutely contraindicated during...

  18. In-situ bioremediation of a hydrocarbon-contaminated pond at Hall Beach, Northwest Territories

    International Nuclear Information System (INIS)

    Eno, R.; Rogers, J.; Heroux, J.; Reimer, K.

    1999-01-01

    The effectiveness of in-situ bioremediation as a means of cleaning up fuel spills in Arctic regions is demonstrated by a case study involving a former fuel tank farm site at Hall Beach, Northwest Territories. An in-situ treatment method, based on the theory of a completely mixed batch wastewater system, was used in this instance. The treatment centred around a commercial floating aerator, which was installed in the pond to provide oxygen. Pre-calculated amounts of nutrients in the form of ammonium chloride and sodium phosphate were also added. The treatment was repeated in the following thawing season to verify initial results. The study is still ongoing; analysis results of the samples collected during the second season are not yet available. However, initial results looked promising and were consistent with what would be expected of increased biological activity. 4 figs

  19. Emerging trends in separation science and technology as practised by Indian Rare Earths Ltd

    International Nuclear Information System (INIS)

    Mukherjee, T.K.

    2004-01-01

    Although the core business of Indian Rare Earths Ltd. (IREL) is mining of Indian Beach Sand deposits and separation of associated six heavy minerals, the Company is also engaged in a strategic activity like recovery of the mineral monazite from the sand and its chemical processing to recover two important nuclear materials and the rare earths. Separation science and technology plays an important role in this particular activity of IREL to produce, in commercial scale, the mineral monazite in desired purity and its chemical processing to recover products like thorium oxalate concentrate, nuclear grade ammonium diuranate, tri sodium phosphate and host of rare earths salts both mixed and separated. This paper to start with, will deal with bulk separation of monazite itself, which has an important bearing on down stream chemical separation process to be discussed in the later half

  20. Separation of saccharides derivatized with 2-aminobenzoic acid by capillary electrophoresis and their structural consideration by nuclear magnetic resonance.

    Science.gov (United States)

    He, Liping; Sato, Kae; Abo, Mitsuru; Okubo, Akira; Yamazaki, Sunao

    2003-03-01

    Saccharides including mono- and disaccharides were quantitatively derivatized with 2-aminobenzoic acid (2-AA). These derivatives were then separated by capillary zone electrophoresis with UV detection using 50mM sodium phosphate buffer as the running electrolyte solution. In particular, the saccharide derivatives with the same molecular weight as 2-AA aldohexoses (mannose and glucose) and 2-AA aldopentoses (ribose and xylose) were well separated. The underlying reasons for separation were explored by studying their structural data using 1H and 13C NMR. It was found that the configurational difference between their hydroxyl group at C2 or C3 could cause the difference in Stokes' radii between their molecules and thus lead to different electrophoretic mobilities. The correlation between the electrophoretic behavior of these carbohydrate derivatives and their structures was studied utilizing the calculated molecular models of the 2-AA-labeled mannose, glucose, ribose, and xylose.

  1. Analytical investigation of different mathematical approaches utilizing manipulation of ratio spectra

    Science.gov (United States)

    Osman, Essam Eldin A.

    2018-01-01

    This work represents a comparative study of different approaches of manipulating ratio spectra, applied on a binary mixture of ciprofloxacin HCl and dexamethasone sodium phosphate co-formulated as ear drops. The proposed new spectrophotometric methods are: ratio difference spectrophotometric method (RDSM), amplitude center method (ACM), first derivative of the ratio spectra (1DD) and mean centering of ratio spectra (MCR). The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitations and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

  2. Bench-scale treatability studies for simulated incinerator scrubber blowdown containing radioactive cesium and strontium

    International Nuclear Information System (INIS)

    Coroneos, A.C.; Taylor, P.A.; Arnold, W.D. Jr.; Bostick, D.A.; Perona, J.J.

    1994-12-01

    The purpose of this report is to document the results of bench-scale testing completed to remove 137 Cs and 90 Sr from the Oak Ridge K-25 Site Toxic Substances Control Act (TSCA) Incinerator blowdown at the K-25 Site Central Neutralization Facility, a wastewater treatment facility designed to remove heavy metals and uranium from various wastewaters. The report presents results of bench-scale testing using chabazite and clinoptilolite zeolites to remove cesium and strontium; using potassium cobalt ferrocyanide (KCCF) to remove cesium; and using strontium chloride coprecipitation, sodium phosphate coprecipitation, and calcium sulfate coprecipitation to remove strontium. Low-range, average-range, and high-range concentration blowdown surrogates were used to complete the bench-scale testing

  3. Determination of Montelukast Sodium and Bambuterol Hydrochloride in Tablets using RP HPLC.

    Science.gov (United States)

    Patil, Smita; Pore, Y V; Kuchekar, B S; Mane, Aruna; Khire, V G

    2009-01-01

    An accurate, specific and precise assay level gradient reverse-phase high-performance liquid chromatographic method was developed for simultaneous determination of montelukast sodium and bambuterol hydrochloride in tablet dosage form. An inertsil ODS C-18, 5 mum column having 250x4.6 mm I.D. in gradient mode, with mobile phase A, containing 0.025 M sodium phosphate buffer: methanol (85:15) and mobile phase B, containing acetonitrile:methanol (85:15) was used at different time intervals. The flow rate was 1.5 ml/min and effluent was monitored at 218 nm. The retention times of montelukast sodium and bambuterol hydrochloride were 21.2 min and 5.8 min respectively. The linearity for both the drugs was in the range of 0.25-0.75 mg/ml with correlation coefficients of 0.9999 and 0.9996 for montelukast sodium and bambuterol hydrochloride, respectively.

  4. Application of fluoridated hydroxyapatite thin film coatings using KrF pulsed laser deposition.

    Science.gov (United States)

    Hashimoto, Yoshiya; Ueda, Mamoru; Kohiga, Yu; Imura, Kazuki; Hontsu, Shigeki

    2018-06-08

    Fluoridated hydroxyapatite (FHA) was investigated for application as an implant coating for titanium bone substitute materials in dental implants. A KrF pulsed excimer deposition technique was used for film preparation on a titanium plate. The compacts were ablated by laser irradiation at an energy density of 1 J/cm 2 on an area 1×1 mm 2 with the substrate at room temparature. Energydispersive spectrometric analysis of the FHA film revealed peaks of fluorine in addition to calcium and phosphorus. X-ray diffraction revealed the presence of crystalline FHA on the FHA film after a 10 h post annealing treatment at 450°C. The FHA film coating exhibited significant dissolution resistance to sodium phosphate buffer for up to 21 days, and favorable cell attachment of human mesenchymal stem cells compared with HA film. The results of this study suggest that FHA coatings are suitable for real-world implantation applications.

  5. The P K-near edge absorption spectra of phosphates

    Science.gov (United States)

    Franke, R.; Hormes, J.

    1995-12-01

    The X-ray absorption near edge structure (XANES) at the P K-edge in several orthophosphates with various cations, in condensed, and in substituted sodium phosphates have been measured using synchrotron radiation from the ELSA storage ring at the University of Bonn. The measured spectra demonstrate that chemical changes beyond the PO 4- tetrahedra are reflected by energy shifts of the pre-edge and continuum resonances, by the presence of characteristic shoulders and new peaks and by differences in the intensity of the white line. We discuss the energy differences between the white line positions and the corresponding P ls binding energies as a measure of half of the energy gap. The corresponding values correlate with the valence of the cations and the intensity of the white lines. The energy positions of the continuum resonances are discussed on the basis of an empirical bond-length correlation supporting a 1/ r2 - dependence.

  6. Some properties of tetravalent actinide phosphates of M1M42(PO4)3 type and peculiarities of their structure

    International Nuclear Information System (INIS)

    Burnaeva, A.A.; Volkov, Yu.F.; Kryukova, A.I.; Skiba, O.V.; Spiryakov, V.I.; Korshunov, I.A.; Samojlova, T.K.

    1987-01-01

    Generalizing analysis of data on crystallographic and IR spectral properties of double phosphates of actinide and alkali elements of M (1) M 2 (4) (PO 4 ) 3 type is conducted. It is shown, that Li - , Na - , K - , Rb - , CsTh 2 (PO 4 ) 3 , Li - , Na - , KU 2 (PO 4 ) 3 , NaNp 2 (PO 4 ) 3 compounds crystallize in a monoclinic type structure and form an isostructural phosphate series. It is ascertained, that in rubidium-uranium, uranium-cesium systems double salt formation is not observed. Plutonium-sodium phosphate has a rhombic-type structure, which points out to the existence of a morphotropic transition in NaM 2 4 (PO 4 ) 3 phosphate series at the Np-Pu boundary. Some regularities of structure and effect of M 1 and M 4 nature on the double phosphate structure are revealed

  7. Technological procedure for chemical cleaning prior to re-pyritization of H2O-H2S isotopic exchange installations

    International Nuclear Information System (INIS)

    Stefanescu, I.; Smaranda, D.; Titescu, Gh.

    1996-01-01

    In normal operation the anti-corrosive shielding of the GS installations undergo a slow, irreversible degradation in time so that after 6 - 8 years their protection characteristics break down. In order to put them back in operation the regeneration of anti-corrosive is required. The procedure achieved at ICIS - Rm.Valcea consists in chemical cleaning of the impaired layers and re-pyritization of the interior surface of installations. Chemical cleaning include the following operations: - mechanical cleaning; - water washing; - alkaline washing with sodium hydroxide, tri-sodium phosphate and sodium tri-polyphosphate; - final mechanical cleaning; - neutralizing washing; - chemical cleaning with phosphoric acid solution; - neutralizing washing. After applying this procedure, the surface is prepared for the pyritization regeneration of the anti-corrosive shielding which ensures the prolongation of the equipment service lifetime with another six year period

  8. Chemical control and design considerations for CANDU-PHW steam generators

    International Nuclear Information System (INIS)

    Frost, C.R.; Churchill, B.R.

    1978-01-01

    Ontario Hydro presently operates eight nuclear power units with a total capacitiy of about 4000 MW(e) net. Operating experience has been with Monel-400 and with Inconel-600 tubed steam generators using sodium phosphate or all volatile control of the boiler steam and water system. With a heavy water Heat Transport System, steam generator tube integrity is an essential ingredient of economical power production. Only three steam generator tube failures have occurred so far in about 40 unit-years operation. None was attributable to corrosion. Factors in the good reliability are, careful engineering design, good quality control at all stages of tubing and steam generator manufacture and close chemical control. The continuing evolution of our steam generator design means that future requirements will be more stringent. (author)

  9. Evidence-based recommendations for bowel cleansing before colonoscopy in children: a report from a national working group.

    Science.gov (United States)

    Turner, D; Levine, A; Weiss, B; Hirsh, A; Shamir, R; Shaoul, R; Berkowitz, D; Bujanover, Y; Cohen, S; Eshach-Adiv, O; Jamal, Gera; Kori, M; Lerner, A; On, A; Rachman, L; Rosenbach, Y; Shamaly, H; Shteyer, E; Silbermintz, A; Yerushalmi, B

    2010-12-01

    There are no current recommendations for bowel cleansing before colonoscopy in children. The Israeli Society of Pediatric Gastroenterology and Nutrition (ISPGAN) established an iterative working group to formulate evidence-based guidelines for bowel cleansing in children prior to colonoscopy. Data were collected by systematic review of the literature and via a national-based survey of all endoscopy units in Israel. Based on the strength of evidence, the Committee reached consensus on six recommended protocols in children. Guidelines were finalized after an open audit of ISPGAN members. Data on 900 colonoscopies per year were accrued, which represents all annual pediatric colonoscopies performed in Israel. Based on the literature review, the national survey, and the open audit, several age-stratified pediatric cleansing protocols were proposed: two PEG-ELS protocols (polyethylene-glycol with electrolyte solution); Picolax-based protocol (sodium picosulphate with magnesium citrate); sodium phosphate protocol (only in children over the age of 12 years who are at low risk for renal damage); stimulant laxative-based protocol (e. g. bisacodyl); and a PEG 3350-based protocol. A population-based analysis estimated that the acute toxicity rate of oral sodium phosphate is at most 3/7320 colonoscopies (0.041 %). Recommendations on diet and enema use are provided in relation to each proposed protocol. There is no ideal bowel cleansing regimen and, thus, various protocols are in use. We propose several evidence-based protocols to optimize bowel cleansing in children prior to colonoscopy and minimize adverse events. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Jose Cabrera (Zorita) tube examination

    International Nuclear Information System (INIS)

    Kuchirka, P.J.

    1986-01-01

    Jose Cabrera (Zorita) tube examination procedures are discussed. This plant continues to use phosphate water chemistry (sodium/phosphate ratio = 2.1). Three hot leg tube segments were pulled from the Jose Cabera (Zorita) plant in 1985. One tube had a field EC indication on the OD at the first tube support plate and the other two had field EC indications on their ID about 3 inches above the bottom of the tube sheet. All three tubes were initially sent to Battelle for preliminary NDE and decontamination. Segments of two tubes were sent to Westinghouse for destructive examination. The results of the laboratory eddy current and radiographic examinations are given. The results of the visual examinations are also given. The tube with OD indications was destructively examined and shallow intergranular pitting and intergranular attack, up to 2 mils deep, were found on the OD in the tube sheet region. Local areas of IGA, up to 5 mils deep, were found on the OD within the tube support plate region. A summary of this information together with supporting micrographs is given. It was hypothesized that a caustic crevice environment was the cause of this mild degradation. Shallow areas of thinning or wastage, up to 3 mils, were found just above the top of the tube sheet in the sludge pile region. Even more shallow wastage was found at the edges of support plate locations. This wastage is believed to be the remnant of early plant chemistry when a higher sodium/phosphate ratio and higher phosphate concentration were allowed

  11. Reuse of hazardous calcium fluoride sludge from the integrated circuit industry.

    Science.gov (United States)

    Zhu, Ping; Cao, Zhenbang; Ye, YiLi; Qian, Guangren; Lu, Bo; Zhou, Ming; Zhou, Jin

    2013-11-01

    The Chinese integrated circuit industry has been transformed from a small state-owned sector into a global competitor, but chip manufacturing produces large amounts of calcium fluoride sludges (CFS). In China, landfill is a current option for treating CFS. In order to solve the problem of unavailable landfill sites and prevent fluorine from dissolved CFS polluting water sources, CFS was tested as a component for a ceramic product made with sodium borate, sodium phosphate and waste alumina using a low-temperature sintering technology, and the effects of various factors on characteristics of the ceramic were investigated to optimize the process. The best sintering temperature was controlled at 700°C, and the optimal raw material ratio of the ceramic was 11% sodium borate, 54% sodium phosphate, 30% CFS and 5% waste alumina. The CFS ceramic was characterized by a morphological structure and X-ray diffraction. The results indicated that CFS was transformed into Na2Ca(PO4)F as an inert and a main crystalline phase in the ceramic, which was enclosed by the borophosphate glass. Toxicity characteristic leaching procedure, corrosion resistance and compressive strength tests verified CFS ceramic as a qualified construction ceramic material, and the fluorine from CFS was solidified in the inert crystalline phase, which would not be released to cause secondary pollution. This novel technology not only avoids the CFS hydrolyzing reaction forming harmful hydrofluoric acid gas at 800°C and above, but also produces high-performance ceramics as a construction material, in accordance with the concept of sustainable development.

  12. Validation of analytical method to calculate the concentration of conjugated monoclonal antibody; Validacao de metodo analitico para calculo de concentracao de anticorpo monoclonal conjugado

    Energy Technology Data Exchange (ETDEWEB)

    Alcarde, Lais F.; Massicano, Adriana V.F.; Oliveira, Ricardo S.; Araujo, Elaine B. de, E-mail: lais_alcarde@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of this study was to develop a quantitative analytical method using high performance liquid chromatography (HPLC) to determine the antibody concentration in conjunction with bifunctional chelator. Assays were performed using a high performance liquid chromatograph, and the following conditions were used: flow rate of 1 mL / min, 15 min run time, 0.2 M sodium phosphate buffer pH 7.0 as the mobile phase and column of molecular exclusion BioSep SEC S-3000 (300 x 7.8 mm, 5 μM - Phenomenex). The calibration curve was obtained with AcM diluted in 0.2 M sodium phosphate buffer pH 7.0 by serial dilution, yielding the concentrations: 400 μg/mL, 200 μg/mL, 100 μg/mL, 50 μg/mL, 25 μg/mL and 12.5 μg/mL. From the calibration curve calculated the equation of the line and with it the concentration of the immunoconjugate. To ensure the validity of the method accuracy and precision studies were conducted. The accuracy test consisted in the evaluation of 3 samples of known concentration, being this test performed with low concentrations (50 μg/mL), medium (100 μg/mL) and high (200 μg/mL). The precision test consisted of 3 consecutive measurements of one sample of known concentration, subject to the conditions set forth above for the other tests. The correlation coefficient of the standard curve was greater than 97%, the accuracy was satisfactory at low concentrations as well as accuracy. The method was validated by showing it for the accurate and precise determination of the concentration of the immunoconjugate. Furthermore, this assay was found to be extremely important, because using the correct mass of the protein, the radiochemical purity of the radioimmunoconjugate was above 95% in all studies.

  13. Effect of buffer and antioxidant on stability of a mercaptopurine suspension.

    Science.gov (United States)

    Aliabadi, Hamidreza Montazeri; Romanick, Marcel; Desai, Sunil; Lavasanifar, Afsaneh

    2008-03-01

    The stability of standard and modified mercaptopurine suspensions when stored at room temperature and under refrigerated conditions to test the feasibility of increasing shelf life was studied. A 50-mg/mL mercaptopurine suspension was compounded by adding simple syrup, cherry syrup, and sterile water for irrigation to triturated mercaptopurine tablets for the initial reference formulation. Three additional formulations were prepared by adding an antioxidant (ascorbic acid 10 mg), a buffer (sodium phosphate monobasic monohydrate 500 mg), and a combination of antioxidant and buffer to the reference formulation. Each compounded batch was divided into two parts and stored in amber bottles at room temperature (19-23 degrees C) or under refrigerated conditions (4-8 degrees C). Analysis through high-performance liquid chromatography determined mercaptopurine levels after three and seven days and weekly thereafter for at least two weeks after shelf life was reached under specified storage conditions. Solutions with at least 93% of the original mercaptopurine concentration and with no observable sign of aggregation or cake formation were considered stable. The reference suspension of mercaptopurine showed an acceptable physical and chemical stability of up to 5 weeks when stored at room temperature. The addition of ascorbic acid extended the shelf life of the compounded suspension to 11 weeks. However, the addition of sodium phosphate monobasic did not improve the stability of mercaptopurine in the suspension. The results showed a higher stability for all formulations after storage at room temperature compared with those stored in a refrigerator. A standard oral suspension of mercaptopurine contained an acceptable drug concentration for up to 5 weeks when stored at room temperature. The addition of ascorbic acid at a concentration of 0.1% w/v to the standard formulation increased the suspension's shelf life at room temperature to 11 weeks.

  14. Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a "pH memory" effect?

    Science.gov (United States)

    Vetráková, Ľubica; Vykoukal, Vít; Heger, Dominik

    2017-09-15

    The concept of "pH memory" has been established in the literature for the correlation between the pH of a pre-lyophilization solution and the ionization state of freeze-dried powder (lyophile). In this paper, the concept of "pH memory" is explored for the system of an aqueous solution, a frozen solution, and a lyophile. Sodium and potassium phosphate buffers in the pH range of 5-9 were frozen and lyophilized with sulfonephthalein indicators as acidity probes, and their Hammett acidity functions were compared to the initial pH of the aqueous solution. The results show that the acidities of the lyophiles are somewhat changed compared to the initial pHs, but the acidities in the frozen state differ more substantially. The Hammett acidity functions of the frozen buffers were found to be markedly dissimilar from the initial pH, especially in the sodium phosphate frozen at 233K, where an increase in the initial pH led to a decrease in the Hammett acidity function of the frozen state at a certain pH range. The large acidification observed after freezing the sodium phosphate buffer was not detected in the lyophiles after the sample had been dried; the phenomenon is explained considering the formed crystals analyzed by X-ray powder diffraction. The results suggest that monitoring the final acidity of a lyophile is not sufficient to predict all the acidity changes throughout the whole lyophilization process. The importance of well-controlled freezing and lyophilization conditions follows from the results of the research. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Anion exchanger 2 is critical for CD8(+) T cells to maintain pHi homeostasis and modulate immune responses

    NARCIS (Netherlands)

    Concepcion, Axel R.; Salas, January T.; Sarvide, Sarai; Sáez, Elena; Ferrer, Alex; López, María; Portu, Ainhoa; Banales, Jesús M.; Hervás-Stubbs, Sandra; Oude Elferink, Ronald P. J.; Prieto, Jesús; Medina, Juan F.

    2014-01-01

    Mitogenic stimulation of lymphocytes involves alkalinization of intracellular pH (pHi ). Subsequent pHi regulation may involve HCO3 (-) extrusion through Cl(-) /HCO3 (-) exchangers and/or Na(+) -HCO3 (-) co-transporters with acid-loading capability. Abnormalities in these mechanisms could result in

  16. Distal truncation of KCC3 in non-French Canadian HMSN/ACC families.

    NARCIS (Netherlands)

    Salin-Cantegrel, A.; Riviere, J.B.; Dupre, N.; Charron, F.M.; Shekarabi, M.; Karemera, L.; Gaspar, C.; Horst, J. van der; Tekin, M.; Deda, G.; Krause, A.; Lippert, M.M.; Willemsen, M.A.A.P.; Jarrar, R.; Lapointe, J.Y.; Rouleau, G.A.

    2007-01-01

    BACKGROUND: Hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC) is a severe and progressive autosomal recessive polyneuropathy. Mutations in the potassium-chloride cotransporter 3 gene (KCC3) were identified as responsible for HMSN/ACC in the French Canadian (FC)

  17. Effect of ATP on intracellular pH in pancreatic ducts involves P2X7 receptors

    DEFF Research Database (Denmark)

    Henriksen, Katerine L; Novak, Ivana

    2003-01-01

    which P2 receptors might be involved. Ducts were obtained from rat pancreas, and the pH sensitive fluorophore BCECF was used to measure pHi and recovery rates from cellular acidosis induced by ammonium pre-pulses. In order to reveal Na+/H+ exchange, Cl-/HCO3- exchange or a Na+-HCO3- cotransport...

  18. Efficacy and safety of canagliflozin when used in conjunction with incretin-mimetic therapy in patients with type 2 diabetes

    NARCIS (Netherlands)

    Fulcher, G.; Matthews, D. R.; Perkovic, V.; de Zeeuw, D.; Mahaffey, K. W.; Mathieu, C.; Woo, V.; Wysham, C.; Capuano, G.; Desai, M.; Shaw, W.; Vercruysse, F.; Meininger, G.; Neal, B.

    Aims: To assess the efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes enrolled in the CANagliflozin cardioVascular Assessment Study (CANVAS) who were on an incretin mimetic [dipeptidyl peptidase-4 (DPP-4) inhibitor or

  19. Rationale, design and baseline characteristics of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) : A randomized, placebo-controlled trial

    NARCIS (Netherlands)

    Neal, Bruce; Perkovic, Vlado; Matthews, David R.; Mahaffey, Kenneth W.; Fulcher, Greg; Meininger, Gary; Erondu, Ngozi; Desai, Mehul; Shaw, Wayne; Vercruysse, Frank; Yee, Jacqueline; Deng, Hsiaowei; de Zeeuw, Dick

    Aims: The primary aim of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) is to determine whether the favourable effects of inhibition of the sodium glucose co-transporter 2 (SGLT2) on blood glucose, blood pressure and body weight are accompanied by protection against adverse renal

  20. Efficacy and Safety of Canagliflozin in Patients with Type 2 Diabetes and Stage 3 Nephropathy

    NARCIS (Netherlands)

    Yamout, Hala; Perkovic, Vlado; Davies, Melanie; Woo, Vincent; de Zeeuw, Dick; Mayer, Cristiana; Vijapurkar, Ujjwala; Kline, Irina; Usiskin, Keith; Meininger, Gary; Bakris, George

    2014-01-01

    Background/Aims: Some sodium glucose co-transporter 2 (SGLT2) inhibitors are approved for the treatment of patients with type 2 diabetes mellitus (T2DM) with an estimated glomerular filtration rate (eGFR) of >= 45 ml/mm/1.73 m(2). The efficacy and safety of canagliflozin, an approved SGLT(2)

  1. Does SGLT2 inhibition with dapagliflozin overcome individual therapy resistance to RAAS inhibition?

    NARCIS (Netherlands)

    Petrykiv, Sergei; Laverman, Gozewijn D.; de Zeeuw, Dick; Heerspink, Hiddo J. L.

    Individual patients show a large variation in their response to renin-angiotensin-aldosteron system (RAAS) inhibition (RAASi), both in surrogates such as albuminuria and in hard renal outcomes. Sodium-glucose co-transporter 2 inhibitors (SGLT2) have been shown to lower albuminuria and to confer

  2. Activity-dependent astrocyte swelling is mediated by pH-regulating mechanisms

    DEFF Research Database (Denmark)

    Larsen, Brian Roland; MacAulay, Nanna

    2017-01-01

    affecting the K(+) transients, pointing to NBCe1 as a key contributor to the stimulus-induced astrocytic cell swelling. Inhibition of the monocarboxylate cotransporters (MCT), like-wise, reduced the ECS shrinkage by ∼25% without compromising the K(+) transients. Isosmotic reduction of extracellular Cl...

  3. nvj 36 1 new.cdr

    African Journals Online (AJOL)

    GRAPHICS DEPT

    activities of cation pumps and Na K cotransport (Lijnen and Petrov, 1995). During lactation, EOF was increased to a greater extent than it was decreased in PRE. The role of hormones that sustain lactation was pertinent in the reducing stability of the erythrocyte membrane. Prolactin alters erythrocyte function by enhancing ...

  4. Local impermeant anions establish the neuronal chloride concentration

    DEFF Research Database (Denmark)

    Glykys, J; Dzhala, V; Egawa, K

    2014-01-01

    Neuronal intracellular chloride concentration [Cl(-)](i) is an important determinant of γ-aminobutyric acid type A (GABA(A)) receptor (GABA(A)R)-mediated inhibition and cytoplasmic volume regulation. Equilibrative cation-chloride cotransporters (CCCs) move Cl(-) across the membrane, but accumulat...

  5. Localization and functional characterization of the human NKCC2 isoforms

    DEFF Research Database (Denmark)

    Carota, I; Theilig, F; Oppermann, M

    2010-01-01

    AIM: Salt reabsorption across the apical membrane of cells in the thick ascending limb (TAL) of Henle is primarily mediated by the bumetanide-sensitive Na(+)/K(+)/2Cl(-) cotransporter NKCC2. Three full-length splice variants of NKCC2 (NKCC2B, NKCC2A and NKCC2F) have been described. The NKCC2 isof...

  6. Cortisol regulation of ion transporter mRNA in Atlantic salmon gill and the effect of salinity on the signaling pathway

    DEFF Research Database (Denmark)

    Kiilerich, Pia; Kristiansen, Karsten; Madsen, Steffen S

    2007-01-01

    Based on real-time RT-PCR, analysis of transcripts of selected ion-regulatory proteins (Na(+), K(+)-ATPase alpha1a and alpha1b subunit, Na(+), K(+), 2Cl(-) cotransporter, cystic fibrosis transmembrane conductance regulator (CFTR), and H(+)-ATPase B-subunit), the regulatory role of cortisol and th...

  7. Metabolic Transition of Milk Lactose Synthesis and Up-regulation by AKT1 in Sows from Late Pregnancy to Lactation.

    Science.gov (United States)

    Chen, Fang; Chen, Baoliang; Guan, Wutai; Chen, Jun; Lv, Yantao; Qiao, Hanzhen; Wang, Chaoxian; Zhang, Yinzhi

    2017-03-01

    Lactose plays a crucial role in controlling milk volume by inducing water toward into the mammary secretory vesicles from the mammary epithelial cell cytoplasm, thereby maintaining osmolality. In current study, we determined the expression of several lactose synthesis related genes, including glucose transporters (glucose transporter 1, glucose transporter 8, sodium-glucose cotransporter 1, sodium-glucose cotransporter 3, and sodium-glucose cotransporter 5), lactose synthases (α-lactalbumin and β1,4-galactosyltransferase), and hexokinases (hexokinase-1 and hexokinase-2) in sow mammary gland tissue at day 17 before delivery, on the 1st day of lactation and at peak lactation. The data showed that glucose transporter 1 was the dominant glucose transporter within sow mammary gland and that expression of each glucose transporter 1, sodium-glucose cotransporter 1, hexokinase-1, hexokinase-2, α-lactalbumin, and β1,4-galactosyltransferase were increased (p lactose synthesis was significantly elevated with the increase of milk production and AKT1 could positively regulate lactose synthesis.

  8. Optimizing the analysis strategy for the CANVAS Program : A prespecified plan for the integrated analyses of the CANVAS and CANVAS-R trials

    NARCIS (Netherlands)

    Neal, Bruce; Perkovic, Vlado; Mahaffey, Kenneth W.; Fulcher, Greg; Erondu, Ngozi; Desai, Mehul; Shaw, Wayne; Law, Gordon; Walton, Marc K.; Rosenthal, Norm; de Zeeuw, Dick; Matthews, David R.

    Two large cardiovascular outcome trials of canagliflozin, comprising the CANVAS Program, will complete in early 2017: the CANagliflozin cardioVascular Assessment Study (CANVAS) and the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R). Accruing data for the sodium glucose co-transporter

  9. NBCe1 (SLC4A4) a potential pH regulator in enamel organ cells during enamel development in the mouse

    NARCIS (Netherlands)

    Jalali, R.; Guo, J.; Zandieh-Doulabi, B.; Bervoets, T.J.M.; Paine, M.L.; Boron, W.F.; Parker, M.D.; Bijvelds, M.J.C.; Medina, J.F.; DenBesten, P.K.; Bronckers, A.L.J.J.

    2014-01-01

    During the formation of dental enamel, maturation-stage ameloblasts express ion-transporting transmembrane proteins. The SLC4 family of ion-transporters regulates intra- and extracellular pH in eukaryotic cells by cotransporting HCO3 − with Na+. Mutation in SLC4A4 (coding for the sodium-bicarbonate

  10. Rates of myocardial infarction and stroke in patients initiated on SGLT2-inhibitors versus other glucose-lowering agents in real-world clinical practice

    DEFF Research Database (Denmark)

    Kosiborod, Mikhail; Birkeland, Kåre I; Cavender, Matthew A

    2018-01-01

    The multinational, observational CVD-REAL study recently showed that initiation of sodium-glucose co-transporter-2 inhibitors (SGLT-2i) was associated with significantly lower rates of death and heart failure vs. other glucose-lowering drugs (oGLDs). This sub-analysis of CVD-REAL sought to determ...

  11. Dapagliflozin Compared to DPP-4 inhibitors is Associated with Lower Risk of Cardiovascular Events and All-cause Mortality in Type 2 Diabetes Patients (CVD-REAL Nordic)

    DEFF Research Database (Denmark)

    Persson, F; Nyström, Thomas; Jørgensen, Marit Eika

    2018-01-01

    AIMS: To compare the sodium glucose-cotransporter-2-inhibitor (SGLT-2i) dapagliflozin versus dipeptidyl peptidase-4 inhibitors (DPP-4i) regarding risk associations of MACE (nonfatal myocardial infarction, nonfatal stroke or cardiovascular [CV] mortality), hospital events for heart failure (HHF), ...

  12. Ameloblast modulation and transport of Cl-, Na+, and K+ during amelogenesis

    NARCIS (Netherlands)

    Bronckers, A.L.J.J.; Lyaruu, D.; Jalali, R.; Medina, J.F.; Zandieh-Doulabi, B.; DenBesten, P.K.

    2015-01-01

    Ameloblasts express transmembrane proteins for transport of mineral ions and regulation of pH in the enamel space. Two major transporters recently identified in ameloblasts are the Na+K+-dependent calcium transporter NCKX4 and the Na+-dependent HPO42- (Pi) cotransporter NaPi-2b. To regulate pH,

  13. Lithium transport across biological membranes

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H

    1990-01-01

    Li+ is actively transported out of cells, and across different epithelia of both mammalian and amphibian origin. Due to the low affinity of the Na+/K(+)-ATPase for Li+, the transport is most likely energized by exchange and/or cotransport processes. The detailed mechanism by which Li+ is reabsorb...

  14. Differential Effects of Dapagliflozin on Cardiovascular Risk Factors at Varying Degrees of Renal Function

    NARCIS (Netherlands)

    Petrykiv, Sergei; Sjostrom, C. David; Greasley, Peter J.; Xu, John; Persson, Frederik; Heerspink, Hiddo J. L.

    2017-01-01

    BACKGROUND AND OBJECTIVE: Sodium glucose cotransporter 2 inhibition with dapagliflozin decreases hemoglobin A1c (HbA1c), body weight, BP, and albuminuria (urinary albumin-to-creatinine ratio). Dapagliflozin also modestly increases hematocrit, likely related to osmotic diuresis/natriuresis. Prior

  15. An anti-NH2-terminal antibody localizes NBCn1 to heart endothelia and skeletal and vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Damkier, Helle Hasager; Nielsen, Søren; Prætorius, Jeppe

    2006-01-01

    The electroneutral sodium bicarbonate cotransporter NBCn1 or NBC3 was originally cloned from rat aorta and from human skeletal muscle. NBCn1 (or NBC3) has been localized to the basolateral membrane of various epithelia, but thus far it has been impossible to detect the protein in these tissues...

  16. Abstracts of Papers Presented at the Annual Meeting of the Society of General Physiologists Held at Woods Hole, Massachusetts on 10-13 September 1992.

    Science.gov (United States)

    1992-09-13

    Qualitative Alteration of K-Cl Cotransport in Red Blood Cells with Hemoglobin S NORMA C. ADRAGNA and PETER K. LAUF, Departments of Pharmacology & Toxicology and...Adair, B. D.. 2 Brant. S. R.. 107. 122, 138 Adragna . N. C.. 139 Breituieser. (G. E., 150 Agre, P.. 127 Brot-Liroche. E., 147 Aitnizo. M.. 43 Browning, K

  17. SGLT2 Inhibition in the Diabetic Kidney—From Mechanisms to Clinical Outcome

    Science.gov (United States)

    Muskiet, Marcel H.A.; Tonneijck, Lennart; Kramer, Mark H.H.; Nieuwdorp, Max; van Raalte, Daniel H.

    2017-01-01

    Diabetic kidney disease not only has become the leading cause for ESRD worldwide but also, highly contributes to increased cardiovascular morbidity and mortality in type 2 diabetes. Despite increased efforts to optimize renal and cardiovascular risk factors, like hyperglycemia, hypertension, obesity, and dyslipidemia, they are often insufficiently controlled in clinical practice. Although current drug interventions mostly target a single risk factor, more substantial improvements of renal and cardiovascular outcomes can be expected when multiple factors are improved simultaneously. Sodium-glucose cotransporter type 2 in the renal proximal tubule reabsorbs approximately 90% of filtered glucose. In type 2 diabetes, the maladaptive upregulation of sodium-glucose cotransporter type 2 contributes to the maintenance of hyperglycemia. Inhibiting these transporters has been shown to effectively improve glycemic control through inducing glycosuria and is generally well tolerated, although patients experience more genital infections. In addition, sodium-glucose cotransporter type 2 inhibitors favorably affect body weight, BP, serum uric acid, and glomerular hyperfiltration. Interestingly, in the recently reported first cardiovascular safety trial with a sodium-glucose cotransporter type 2 inhibitor, empagliflozin improved both renal and cardiovascular outcomes in patients with type 2 diabetes and established cardiovascular disease. Because the benefits were seen rapidly after initiation of therapy and other glucose-lowering agents, with the exception of liraglutide and semaglutide, have not been able to improve cardiovascular outcome, these observations are most likely explained by effects beyond glucose lowering. In this mini review, we present the drug class of sodium-glucose cotransporter type 2 inhibitors, elaborate on currently available renal and cardiovascular outcome data, and discuss how the effects of these agents on renal physiology may explain the data. PMID

  18. Renal Dysfunction Induced by Kidney-Specific Gene Deletion of Hsd11b2 as a Primary Cause of Salt-Dependent Hypertension.

    Science.gov (United States)

    Ueda, Kohei; Nishimoto, Mitsuhiro; Hirohama, Daigoro; Ayuzawa, Nobuhiro; Kawarazaki, Wakako; Watanabe, Atsushi; Shimosawa, Tatsuo; Loffing, Johannes; Zhang, Ming-Zhi; Marumo, Takeshi; Fujita, Toshiro

    2017-07-01

    Genome-wide analysis of renal sodium-transporting system has identified specific variations of Mendelian hypertensive disorders, including HSD11B2 gene variants in apparent mineralocorticoid excess. However, these genetic variations in extrarenal tissue can be involved in developing hypertension, as demonstrated in former studies using global and brain-specific Hsd11b2 knockout rodents. To re-examine the importance of renal dysfunction on developing hypertension, we generated kidney-specific Hsd11b2 knockout mice. The knockout mice exhibited systemic hypertension, which was abolished by reducing salt intake, suggesting its salt-dependency. In addition, we detected an increase in renal membrane expressions of cleaved epithelial sodium channel-α and T53-phosphorylated Na + -Cl - cotransporter in the knockout mice. Acute intraperitoneal administration of amiloride-induced natriuresis and increased urinary sodium/potassium ratio more in the knockout mice compared with those in the wild-type control mice. Chronic administration of amiloride and high-KCl diet significantly decreased mean blood pressure in the knockout mice, which was accompanied with the correction of hypokalemia and the resultant decrease in Na + -Cl - cotransporter phosphorylation. Accordingly, a Na + -Cl - cotransporter blocker hydrochlorothiazide significantly decreased mean blood pressure in the knockout mice. Chronic administration of mineralocorticoid receptor antagonist spironolactone significantly decreased mean blood pressure of the knockout mice along with downregulation of cleaved epithelial sodium channel-α and phosphorylated Na + -Cl - cotransporter expression in the knockout kidney. Our data suggest that kidney-specific deficiency of 11β-HSD2 leads to salt-dependent hypertension, which is attributed to mineralocorticoid receptor-epithelial sodium channel-Na + -Cl - cotransporter activation in the kidney, and provides evidence that renal dysfunction is essential for developing the

  19. Biochemical Stability and Molecular Dynamic Characterization of Aspergillus fumigatus Cystathionine γ-Lyase in Response to Various Reaction Effectors

    KAUST Repository

    El-Sayed, Ashraf S.A.; Abdel-Azeim, Safwat; Ibrahim, Hend M.; Yassin, Marwa A.; Abdel-Ghany, Salah E.; Esener, Sadik; Ali, Gul Shad

    2015-01-01

    Cystathionine γ-lyase (CGL) is a key enzyme in the methionine-cysteine cycle in all living organisms forming cysteine, α-ketobutyrate and ammonia via homocysteine and cystathionine intermediates. Although, human and plant CGLs have been extensively studied at the molecular and mechanistic levels, there has been little work on the molecular and catalytic properties of fungal CGL. Herein, we studied in detail for the first time the molecular and catalytic stability of Aspergillus fumigatus CGL, since conformational instability, inactivation and structural antigenicity are the main limitations of the PLP-dependent enzymes on various therapeutic uses. We examined these properties in response to buffer compositions, stabilizing and destabilizing agents using Differential Scanning Fluorometery (DSF), steady state and gel-based fluorescence of the intrinsic hydrophobic core, stability of internal aldimine linkage and catalytic properties. The activity of the recombinant A. fumigatus CGL was 13.8 U/mg. The melting temperature (Tm) of CGL in potassium phosphate buffer (pH 7.0-8.0) was 73.3 °C, with ∼3 °C upshifting in MES and sodium phosphate buffers (pH 7.0). The conformational thermal stability was increased in potassium phosphate, sodium phosphate and MES buffers, in contrast to Tris-HCl, HEPES (pH 7.0) and CAPS (pH 9.0-10.0). The thermal stability and activity of CGL was slightly increased in the presence of trehalose and glycerol that might be due to hydration of the enzyme backbone, unlike the denaturing effect of GdmCl and urea. Modification of surface CGL glutamic and aspartic acids had no significant effect on the enzyme conformational and catalytic stability. Molecular modeling and dynamics simulations unveil the high conformational stability of the overall scaffold of CGL with high flexibility at the non-structural regions. CGL structure has eight buried Trp residues, which are reoriented to the enzyme surface and get exposed to the solvent under

  20. Biochemical Stability and Molecular Dynamic Characterization of Aspergillus fumigatus Cystathionine γ-Lyase in Response to Various Reaction Effectors

    KAUST Repository

    El-Sayed, Ashraf S.A.

    2015-08-11

    Cystathionine γ-lyase (CGL) is a key enzyme in the methionine-cysteine cycle in all living organisms forming cysteine, α-ketobutyrate and ammonia via homocysteine and cystathionine intermediates. Although, human and plant CGLs have been extensively studied at the molecular and mechanistic levels, there has been little work on the molecular and catalytic properties of fungal CGL. Herein, we studied in detail for the first time the molecular and catalytic stability of Aspergillus fumigatus CGL, since conformational instability, inactivation and structural antigenicity are the main limitations of the PLP-dependent enzymes on various therapeutic uses. We examined these properties in response to buffer compositions, stabilizing and destabilizing agents using Differential Scanning Fluorometery (DSF), steady state and gel-based fluorescence of the intrinsic hydrophobic core, stability of internal aldimine linkage and catalytic properties. The activity of the recombinant A. fumigatus CGL was 13.8 U/mg. The melting temperature (Tm) of CGL in potassium phosphate buffer (pH 7.0-8.0) was 73.3 °C, with ∼3 °C upshifting in MES and sodium phosphate buffers (pH 7.0). The conformational thermal stability was increased in potassium phosphate, sodium phosphate and MES buffers, in contrast to Tris-HCl, HEPES (pH 7.0) and CAPS (pH 9.0-10.0). The thermal stability and activity of CGL was slightly increased in the presence of trehalose and glycerol that might be due to hydration of the enzyme backbone, unlike the denaturing effect of GdmCl and urea. Modification of surface CGL glutamic and aspartic acids had no significant effect on the enzyme conformational and catalytic stability. Molecular modeling and dynamics simulations unveil the high conformational stability of the overall scaffold of CGL with high flexibility at the non-structural regions. CGL structure has eight buried Trp residues, which are reoriented to the enzyme surface and get exposed to the solvent under