High Concentrations Of Sodium Ions Research Articles

Abolition of intrinsically bent DNA structure components in AT clusters by netropsin interaction; titration viscometric investigations.

It is argued that the enhancement of the apparent DNA contour length by the specifically binding non-intercalating drug netropsin (Nt) (Reinert et al., NAR 9, 2335, 1981) at very low Nt/DNA-phosphate ratios essentially is the result of an abolition of periodically arranged intrinsic helix bends in A.T rich tracts of base pairs. In the preceding paper the existence of pronounced DNA tertiary structure components has been postulated for (two species of) natural eukaryotic DNA. The resulting model suggests local apparent solenoid-related DNA tertiary structure components at high sodium ion concentration cs, partly/totally molten out at 45/60 C. With decreasing cs the tertiary structure components have been found to be gradually reduced, at least below cs = 0.010 M, as titration viscometrically revealed by a gradual rise of the apparent DNA contour length (Reinert et al., JBSD 9, 537, 1991). Hence, we performed titration viscometric analyses about Nt interaction with calf thymus DNA (ctDNA) at cs = 0.075 M, 0.010 M and 0.004 M Na+. The concomitant DNA conformational changes are quantitatively described in terms of the relative changes of both DNA persistence length and hydrodynamically operative apparent DNA contour length for the three first resolved interaction modes below a Nt/DNA-P ratio of 0.03. These experiments, together with previous respective analyses at cs = 0.20 M Na+ and different temperatures (l.c.), suggest that those DNA sites binding Nt most strongly predominantly are responsible for the formation of solenoid-related DNA tertiary structure components. Most probably these are A tract-containing sequences. As the essential factor for their apparent elongation effect at low Na+ concentrations, a gradual alteration of the number of base pairs per helix turn seems to occur below cs = 0.010 M Na+ and, concomitantly, a change in phasing between intrinsic helix bends and helix screw.

Influence of ionic parameters on the growth and distribution of Boekelovia hooglandii (Chromophyta)

Abstract The small, flagellated monad Boekelovia hooglandii Nicolai et Baas Becking (Chromophyta) has not been reported in the literature since its initial discovery in a saline swimming pool in the Netherlands in 1935. This alga was recently observed in several temporary saline ponds in the central and western USA. The water where the alga was most abundant was characterized by a high concentration of sodium and bicarbonate ions, and a high monovalent: divalent (M: D) ionic ratio. Results of experiments to evaluate the growth and photosynthetic efficiency of B. hooglandii in several water types indicated that the alga exhibited its optimum growth rate and photosynthetic efficiency in watertypes with high M : D ratios. Growth rates tended to decline when divalent cation concentrations exceeded 20 mM. Despite exhibiting optimum growth in high M : D waters, the data also indicated that B. hooglandii could grow relatively well in lower M : D saline waters, such as seawater. Factors other than ionic compositi...

Inverse Salinity Gradients in Coastal Marshes and the Death of Stands of Salix: The Effects of Grubbing by Geese

SUMMARY (1) The formation of large 'peat barrens' (> 100 m x 100m) produced as a result of grubbing (removal of roots and rhizomes of ground vegetation) by lesser snow geese in the spring was investigated in a low Salix community inland from the intertidal zone at La Perouse Bay, Manitoba. (2) Within the snow-free season, experimental removal of the insulating mat of plant litter and ground vegetation resulted in increased temperatures of soils close to the surface, increased thermal gradients in soils and a substantial increase in the salinity (- 120 g of dissolved solids litre -1) of expressed water from the shallow organic layer that overlays the marine clays and gravels (salinity of tidal water was < 4gV-1). (3) Although marine sediments beneath the organic layer are the ultimate source of salt, the inverse salinity gradient from land to sea reported for coastal marshes of Hudson Bay appears to be the result of grubbing, at least at La Perouse Bay. (4) Premature leaf fall occurred from side shoots of Salix beneath which the graminoid sward had been artificially grubbed. No premature leaf fall from undisturbed Salix was detected. Early leaf death was correlated with high foliar concentrations of sodium and chloride ions. (5) Salix from artificially grubbed areas failed to develop leaves the following season and 24 months after removal of turf plants were dead. (6) It is concluded that spring grubbing by geese initiates a series of environmental changes which make it unlikely that the original plant communities will reestablish in the foreseeable future (< 15 years).

Sodium ion-dependent amino acid transport in membrane vesicles of Bacillus stearothermophilus.

Amino acid transport in membrane vesicles of Bacillus stearothermophilus was studied. A relatively high concentration of sodium ions is needed for uptake of L-alanine (Kt = 1.0 mM) and L-leucine (Kt = 0.4 mM). In contrast, the Na(+)-H(+)-L-glutamate transport system has a high affinity for sodium ions (Kt less than 5.5 microM). Lithium ions, but no other cations tested, can replace sodium ions in neutral amino acid transport. The stimulatory effect of monensin on the steady-state accumulation level of these amino acids and the absence of transport in the presence of nonactin indicate that these amino acids are translocated by a Na+ symport mechanism. This is confirmed by the observation that an artificial delta psi and delta mu Na+/F but not a delta pH can act as a driving force for uptake. The transport system for L-alanine is rather specific. L-Serine, but not L-glycine or other amino acids tested, was found to be a competitive inhibitor of L-alanine uptake. On the other hand, the transport carrier for L-leucine also translocates the amino acids L-isoleucine and L-valine. The initial rates of L-glutamate and L-alanine uptake are strongly dependent on the medium pH. The uptake rates of both amino acids are highest at low external pH (5.5 to 6.0) and decline with increasing pH. The pH allosterically affects the L-glutamate and L-alanine transport systems. The maximal rate of L-glutamate uptake (Vmax) is independent of the external pH between pH 5.5 and 8.5, whereas the affinity constant (Kt) increases with increasing pH. A specific transport system for the basic amino acids L-lysine and L-arginine in the membrane vesicles has also been observed. Transport of these amino acids occurs most likely by a uniport mechanism.

Study of iron/mordenite catalysts by Mössbauer and ferromagnetic resonance spectroscopy for carbon monoxide hydrogenation

Iron was loaded on mordenites with varying cation type and degree of dealumination, and their catalytic properties were characterized by means of Mössbauer and ferromagnetic resonance spectroscopy and carbon monoxide hydrogenation as a probe reaction. When iron was impregnated on mordenites, it was found that about 1.2 wt.-% of iron existed as ion-exchanged cationic iron in the oxide or hydroxide form. Iron oxide particles formed after calcination at 450°C showed a wide distribution in their size, ranging from cluster-sized superparamagnetic oxide to large particles of α-Fe2O3. After reduction at 450°C, iron oxide particles were sintered to be reduced to bimodally distributed metallic iron particles. Small iron particles generated on hydrogen-form mordenites are believed to be stabilized by some defect sites generated by dealumination of mordenite. On sodium-mordenite, extremely small and uniform iron clusters were generated because free sodium ions, which had been detached from the framework by previous ion exchange with impregnated iron ions, promoted reduction of ion-exchanged cationic irons. The result was applied to reduce ion-exchanged iron (FeNaM10) by injecting a high concentration of sodium ions into the pores of mordenite and about 27% of the iron was able to be reduced upon treatment in hydrogen gas at 450°C. These iron clusters showed lower activity but higher selectivity toward alkenes in the carbon monoxide hydrogenation reaction than conventional impregnated catalysts.

Effects of urinary potassium and sodium ion concentrations and pH on N-butyl-N(4-hydroxybutyl)nitrosamine-induced urinary bladder carcinogenesis in rats

The promoting activities of low and high sodium or potassium ion concentrations, under conditions of neutral as well as elevated urinary pH, in urinary bladder carcinogenesis, were investigated in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Male Wistar rats were given 0.05% BBN in their drinking water for 4 weeks and then treated for 32 weeks with either control diet (group 1) or this diet supplemented with equimolar amounts of the following minerals: 2.34% NaCl (group 2), 2.98% KCl (group 3), 3.36% NaHCO3 (group 4), 1.68% NaHCO3 + 2% KHCO3 (group 5), or 4% KHCO3 (group 6). The alkalizing salts NaHCO3 and KHCO3 induced comparable increases in urinary pH and elevated urinary sodium or potassium ion concentrations respectively. The combination of NaHCO3 + KHCO3 similarly caused an elevation of the urinary pH and less increased sodium and potassium ion concentrations. In the groups fed NaHCO3 and KHCO3 either alone or in combination, the incidences of papillary/nodular hyperplasia, papillomas and carcinomas in the urinary bladder had increased as compared to controls. NaCl and KCl also induced high urinary sodium or potassium ion concentrations without alteration of urinary pH. This was accompanied by increased incidences of simple hyperplasia, papillary/nodular hyperplasia, and/or papillomas but no carcinomas. The present results indicate that the potassium ion is as potent as the sodium ion in promoting urinary bladder carcinogenesis under conditions of elevated urinary pH, and that both the sodium and potassium ions may exert weak promoting activity under conditions of neutral urinary pH.

Demonstration of adenylate cyclase activity in stria vascularis of guinea pig cochlea

Cholera toxin-stimulated adenylate cyclase activity was demonstrated cytochemically in the stria vascularis of the guinea pig inner ear by the cerium method of Rechardt and Hervonen, and it was compared with ALPase, Mg-ATPase, Ca-ATPase and Na, K-ATPase activity. Adenylate cyclase activity was observed in the marginal and basal cells. The reaction products were fine granular particles on the plasma membrane of the basal infoldings of the marginal cells, but not on that of the free surface facing the endolymphatic space. Enzyme activity was also observed in the large mitochondria;the reaction was intense in the outer chamber and weak in the cristae, was inhibited by 5 mM alloxan. The plasma membranes of adjacent basal cells showed a positive rea-ction. No enzyme activity was detected in the intermediate cells, the endothelial cells of the capillaries in the stria vascularis, fibrocytes in the spiral ligament, epithelial cells of the spiral prominence, Corti's organ or Reissner's membrane. In the marginal cells, the location of adenylate cyclase activity corresponded with that of Na, K-ATPase activity. Therefore, the adenylate cyclase activity of the stria vascularis may play a role in the regulation of the membrane permea-bility to water and electrolytes while Na, K-ATP-ase acts as an ion pump to maintain high potassium and low sodium ion concentrations in the endolymph.

The sodium responsive tungsten bronze electrode: An electrode for sodium ion analysis of DNA solutions

The preparation and construction of tungsten bronze electrodes, responsive to sodium ions, are reported. The electrodes were made from tungsten bronze powder (Na 0.4WO 3), compressed into pellets with a resin binder and sealed in epoxy resin. The electrodes were found to respond almost instantenously to changes in sodium ion concentration and to be relatively stable with time. The pH dependence decreases as the sodium ion concentration increases, indicating suitability for solutions of sea water concentration. Unfortunately the electrodes show a response to potassium ions of apparently equal magnitude to the sodium response between 0.001 mol kg −1 and 0.1 mol kg −1. Preliminary tests indicate that they also respond to lithium, calcium, aluminium, cupric and tetramethylammonium ions at concentrations of 0.1 mol kg −1. At high sodium ion concentrations (⩾ 1 mol kg −1) the effect of cross sensitivity is negligible for these ions. No attempts are made in this short paper to evaluate selectivity coefficients. Some data demonstrating the low but linear response to sodium ion are given. Tests carried out in DNA—saline-bearing solutions suggest that the possible suitability for marine or biological applications.

SEPARATION OF CESIUM FROM NUCLEAR WASTE SOLUTIONS WITH HEXACYANOFERRATE(II)S AND AMMONIUM PHOSPHOMOLYBDATE

Abstract ABSTRACT The separation of 134, 137 Cs from nuclear power plant low-level waste solutions by ion exchange with potassium cobalt hexacyano-ferrate(II), potassium copper cobalt hexacyanoferrate(II) and ammonium phosphomolybdate was studied. The pH of the waste solutions was 6-13 and the concentrations of sodium and potassium ions were 8 - 2700 and 0.5 - 240 mmol/1, respectively. The distribution coefficient of cesium was determined as a function of pH, sodium and potassium ion concentrations and of the ratio of solution volume to exchanger weight (batch factor). The ion exchange rate of cesium was determined for three exchanger grain sizes and at temperatures of 20, 40 and 60° C. A potassium copper cobalt hexacyanoferrate(II) column was tested for cesium separation from a highly alkaline (pH 13) waste solution containing high concentrations of sodium (2.7 M) and potassium (0.24 M) ions; the 1% breakthrough capacity was very high, 12800 bed volumes.

Effects of monensin and ouabain on the cationized ferritin uptake in the marginal cells of the guinea pig stria vascularis

The uptake of cationized ferritin (CF) by the empty vesicles in the apical cytoplasm of the marginal cells of the stria vascularis and the effects of monensin and ouabain on the CF uptake were electron microscopically and morphometrically studied. When 20μg/ml CF with high (145mM) or low (15mM) Na ion concentrations were applied to the cochlea for 10 min, CF particles were found in clusters, scattered on the free-surface plasma membrane facing the endolymph, and in the caveolae of the marginal cells. They were also observed in the empty vesicles, coated vesicles and multivesicular bodies, but not in the Golgi apparatus, endoplasmic reticulum and intercellular space between cells constituting the stria vascularis. The P-face profile of the vesicles was similar to that of the caveolae with regard to the number of intramembranous particles. Monensin, which inhibits receptor-mediated endocytosis, reduced the number of CF-containing vesicles under high sodium ion concentration. These findings suggest that the empty vesicles are associated with the free-surface plasma membrane, and that they ate involved in the efficient exchange of ions between the endolymph and the marginal cells. Ouabain repressed the uptake of CF, lowering the endocochlear potential and altering the normal intracellular environment of the marginal cells. Therefore, the dynamics of the empty vesicles may be related with the sodium-pump in the basolateral infolded plasma membrane of these cells.

Analytical Figures of Merit and Interelement Effects with Air and Nitrogen Microwave-Induced Plasmas

A microwave (2450 MHz)-induced plasma (MIP) with nitrogen nebulization and plasma gases was developed and compared with an air-MIP similar to that previously reported in our laboratories. These plasmas were maintained at 300 to 500 W of forward power and were stable with pneumatic nebulized aqueous solution introduction. In general, metals with high metal-oxygen bond strengths, high excitation energies, and low ionization potentials exhibited superior detection limits in the N2-MIP. Several elements with emission lines in N2 and N2+ spectral regions yielded better detection limits in the air plasma. The effects of high concentrations (2%) of calcium, potassium, sodium, and phosphate ions upon the analytical signal intensities were examined. During direct solution nebulization, the analytical signals of both plasmas exhibited significant but predictable interferences from metals of low ionization potential and plasma loading. Matrix effects were more significant in the N2-MIP.

Ultrastructure of the perfused rat epididymis: effect of luminal sodium ion concentration.

The appearance of the rat epididymal epithelium changed when it was perfused in vivo through the lumen with unphysiologically high sodium ion concentrations; dilatation of intercellular spaces (ICS) at threshold concentrations of 30 mM-Na+ in the cauda and about 55 mM-Na+ in the corpus was associated with absorption of water from the lumen. Despite the distended ICS, junctional complexes appeared intact, and their integrity was confirmed by the exclusion of luminal horseradish peroxidase (HRP) from the ICS, and by demonstrating that circulating [3H]inulin did not enter the lumen. Smooth ER and lipid droplets in the principal cells of the corpus epididymidis were well maintained, and the preservation of granular ER in principal cells of the cauda epididymidis lent morphological support to the continued secretion of protein in this segment. However, occasional distension or involution of inner Golgi cisternae was evident in principal cells after 3-6 h perfusion. In contrast to multivesicular bodies of principal cells, the apical and basal vacuoles characteristic of clear cells changed in size with different perfusion. In contrast to multivesicular bodies of principal cells, the apical and basal vacuoles characteristic of clear cells changed in size with different perfusing solutions. When low Na+ concentrations were perfused large translucent vacuoles were frequently found in the apical cytoplasm of clear cells in the corpus and cauda epididymidis, and filled vacuoles became larger and showed a decrease in content density in the cauda epididymidis. These large vacuoles were absent from tissue perfused with high Na+ concentrations. Normal pinocytotic activity of both cell types was demonstrated by perfusing HRP which was taken up by the normal route in principal cells, with some transfer to the Golgi cisternae. By far the most HRP was accumulated in clear cell vacuoles irrespective of the composition of the perfusing solution.

Epithelial structure of the rat cauda epididymidis after luminal perfusion.

When solutions containing high concentrations of sodium ions (c. 140 mM) were perfused for up to 6 h through the lumen of the cauda epididymidis of the anaesthetised rat, distended spaces were consistently seen between the epithelial cells, water resorption was measurable, and clear cells lacked large clear apical vacuoles. Lowering the sodium ion concentration decreased water resorption, and distended intercellular channels were absent. Under these conditions clear cells had abnormally large or numerous pale staining vacuoles. When physiological concentrations of sodium (20 mM) and potassium (50 mM) ions were perfused, a more normal epithelium was present; intercellular channels were absent, and water was either resorbed or secreted at low rates. Clear cells appeared normal initially, but had abnormal appearance after longer periods of perfusion.

The effects of high concentrations of sodium or calcium ions on the lipid composition and properties of Tetrahymena membranes

Tetrahymena pyriformis cells have been grown in media varying in NaCl concentration from 3.7 mM (normal medium) to 0.3 M and varying in CaCl 2 from 0.2 mM (normal medium) to 0.1 M. Tetrahymena grown in 0.3 M NaCl showed relatively few alterations in phospholipid composition, with significant changes being found only in the cell surface membranes (pellicle), which increased in phosphatidylethanolamine content from 39% (low Na +) to 48% (high Na +) of the total phospholipids. The small decrease in fatty acid unsaturation and increase in shorter chain fatty acids in pellicle phospholipids were not statistically significant. No significant changes in phospholipid head group composition or fatty acid distribution were observed in high Ca 2+-grown cells. Complementary studies of membrane fluidity, as inferred from freeze-fracture electron microscopy analysis, indicated that membranes of high Na +-acclimated cells were similar to those of control cells, when each was measured in its respective medium. However, the outer alveolar membrane of the pellicle and the food vacuolar membrane were considerably less fluid in high-Ca 2+ cells. The lower fluidity in vacuolar membranes may have been responsible for alterations in the cells' capacity to form food vacuoles.

Synthesis of protodolomite from aqueous solution at normal temperature and pressure.

To estimate the conditions of the protodolomite formation, laboratory syntheses from simple aqueous solutions have been carried out under normal temperature and pressure conditions. Protodolomites have been synthesized from CaCl2 + MgCl2 + (NaCl) + NaHCO3 solutions. This paper shows the concentrations of calcium and magnesium ions in the parent solution, which are required for the protodolomite formation. The synthesis experiment indicates that concentrated seawater is favorable to the protodolomite formation. That is, the high value of [Mg2+] / [Ca2+], and the high concentrations of sodium and chlorine ions in a parent solution are favorable to the protodolomite formation.

Effect of ouabain upon erythrocyte membrane adenosine triphosphatase in Duchenne muscular dystrophy

The adenosine triphosphatase activity of erythrocyte ghosts from patients with Duchenne muscular dystrophy was inhibited by 10 −4 M ouabain to a smaller extent than in normals, when measured in the presence of either high or low concentrations of sodium or potassium ions. The inhibition by ouabain of the enzyme in normal ghosts, measured with low sodium or potassium ions, was less if the erythrocytes were first incubated with plasma from Duchenne patients than if incubated with normal plasma. Similar results were obtained when the ghosts themselves were incubated with Duchenne or normal plasma before assay.

Synthesis of adenosine triphosphate and exchange between inorganic phosphate and adenosine triphosphate in sodium and potassium ion transport adenosine triphosphatase.

Radioactive adenosine triphosphate was synthesized transiently from adenosine diphosphate and radioactive inorganic phosphate by sodium and potassium adenosine triphosphatase from guinea pig kidney. In a first step, K+-sensitive phosphoenzyme was formed from radioactive inorganic phosphate in the presence of magnesium ion and 16 mM sodium ion. In a second step the addition to the phosphoenzyme of adenosine diphosphate with a higher concentration of sodium ion produced adenosine triphosphate. Recovery of adenosine triphosphate from the phosphoenzyme was 10 to 100% in the presence of 96 to 1200 mM sodium ion, respectively. Potassium ion (16mM) inhibited synthesis if added before or simultaneously with the high concentration of sodium ion but had no effect afterward. The half-maximal concentration for adenosine diphosphate was about 12 muM. Ouabain inhibited synthesis. The ionophore gramicidin had no significant effect on the level of phosphoenzyme nor on the rate nor on the extent of synthesis of adenosine triphosphate. The detergent Lubrol WX reduced the rate of phosphoenzyme break-down and the rate of synthesis but did not affect the final recovery. Phospholipase A treatment inhibited synthesis. In a steady state, the enzyme catalzyed a slow ouabain-sensitive incorporation or inorganic phosphate into adenosine triphosphate. These results and other suggest that binding of sodium ion to a low affinity site on phosphoenzyme formed from inorganic phosphate is sufficient to induce a conformational change in the active center which permits transfer of the phosphate group to adenosine diphosphate.

Improved techniques for the fractionation of non-histone proteins of chromatin on hydroxyapatite.

The effect of the dissociation medium on the fractionation of chromatin on hydroxyapatite has been studied. Optimal separations of the histones and non-histone protein are only achieved when columns are run in buffers containing high concentrations of sodium ions. We have modified our previously published method such that the chromosomal proteins can be recovered in virtually quantitative yields. Each of the hydroxyapatite fractions has been analysed with respect to nucleic acid content and the proteins have been analysed by two-dimensional gel electrophoresis.

Effect of Exogenous Fatty Acids on the Cellular Fatty Acid Composition and Neomycin Formation in a Mutant Strain ofStreptomyces fradiae

A mutant of Streptomyces fradiae which requires oleic acid for neomycin formation was isolated and the effects of exogenous fatty acids and other additives on the formation of neomycin were studied. Palmitic acid and high concentration of sodium ions could replace oleic acid in neomycin formation. The fatty acid spectrum of the mutant strain ST–5B was quite different from that of the parent strain 3123. The major fatty acid components of the mutant and the parent were anteiso 15:0 and iso 16: 0, respectively. However the fatty acid composition of the mutant was changed from the anteiso 15: 0-type to the parental iso 16: 0-type by the supplement of oleic acid or high concentration of sodium ions in the medium. In the case of palmitic acid, the major fatty acid component of the mutant cells was changed from anteriso 15: 0 to normal 16:0. The role of these additives in neomycin formation by the mutant is discussed.

Water and ion regulation in cicadas in relation to xylem feeding

Cicadas feed on xylem fluid. This is hypotonic to the haemolymph and contains high concentrations of potassium, sodium, calcium, magnesium, chloride, and phosphate ions. The urine contains the same ions in the same proportions but in slightly lower concentrations. Amino acids and sucrose are present in xylem fluid and traces of amino acids are also found in urine. Water is rapidly shunted from foregut to hindgut via the filter chamber. Injection of xylem fluid into the oesophagus results in an immediate tenfold increase in flow rate in the ileum. The osmotic pressure of xylem fluid in the filter chamber rapidly rises whilst the osmotic pressure in the anterior part of the ileum rapidly falls. Absorption of nutrients and ions into the haemolymph probably occurs in the conical segment and anterior tubular midgut. Storage excretion of divalent ions occurs in the mid-midgut and ions may be transported from the haemolymph into the posterior tubular midgut. The Malpighian tubules secrete a fluid slightly hypertonic to blood containing K + (42 mM/l.] and Na + (14 mM/l.). The osmotic pressures within the internal Malpighian tubules and internal midgut in the filter chamber are considerably higher than the osmotic pressure of the xylem fluid when it first enters the filter chamber proper. Passive osmosis will occur and water will be shunted into the ileum. Reabsorption of K + and Na + occurs in the ileum.