Addition Of Ammonium Chloride Research Articles

Effect of glutamine deprivation and glutamate or ammonium chloride addition on growth rate, metabolism and differentiation of human colon cancer cell-line HT29

1. 1. Effect of glutamine deprivation (GLN- medium) and of its replacement by 4mM ammonium chloride (GLN-/NH 4+ medium) or by 4mM glutamate (GLN-/Gt+ medium) was studied on growth rate, morphology and metabolism of HT29 human colon cancer cells. 2. 2. Growth rates were modified as follows: at the first passage, growth of GLN- cells was strongly decreased (doubling time: 192 hr vs 32 hr in control cells grown in GLN + medium); GLN-/NH4+ cells and GLN — /Gt + cells were found to have doubling times of 72 and 70 hr, respectively. At the 8th passage. doubling times were decreased in all cases, being: 144 hr for GLN- cells, 60 hr for GLN-/NH4+ cells and 24 hr for GLN-/Gt+ cells, which indicates a capacity of adaptation of the cell-line to new culture conditions. 3. 3. GLN- cells and GLN-/NH4+ cells were found to exhibit an enterocytic type of differentiation (polarization of the cell layer with apical and cystic brush border and tight junctions): GLN - /Gt + cells remained undifferentiated and comparable to control GLN+ cells. 4. 4. Glycogen level varied according to the phases of the culture, with a trend to lower level in glutamine deprived cells; glucose uptake and lactate production varied as a function of the medium composition and of the phases of the culture. At the 8th passage, all the glutamine deprived cells produced less lactate than control: GLN-/Gt + cells were found to utilize less glucose than others.

Ammonium acceleration of glycolysis in the ethanol fermentation in a high corn system.

A non-saccharified high stress corn mash system was used to study the acceleration of glycolysis in glucose ethanol fermentation by Saccharomyces cerevisiae. It was found that the controlled addition of ammonium sulfate or ammonium chloride resulted in an accelerated glycolytic rate, independent of the final ethanol yield. Adding high levels of ammonium salt, however, resulted in decreased extracellular pH and delayed cessation of fermentation. The delayed cessation of ethanol production was due to the decrease in extracellular pH, which could be controlled by the addition of citrate buffer.

Modification of conspecific chemo-attraction in arctic charr, Salvelinus alpinus (l.), by nitrogenous excretory products

1. 1. The influence of nitrogenous excretory products, l-alanine and ammonium chloride, on the strength of olfactory mediated attraction of juvenile Arctic charr to water scented by two, 10 or 20 conspecifics was studied in a fluviarium. 2. 2. The test fish was strongly attracted to water scented by charr, but with addition of l-Ala to a concentration of 4.6 μM, the water became repellant with two donors, with 10 donors the response varied from one charr to the other, i.e. either attraction or avoidance. 3. 3. Addition of ammonium chloride to a concentration of 5.6 μM in water scented by two donors gave an indifferent reaction, but with 20 donors the same concentration of ammonium chloride gave no reduction in the strength of attraction. 4. 4. Accordingly, it appears that nitrogenous excretion products can modulate the attractive effect of water containing conspecific attractants.

The Effect of Ammonium Chloride and Fluid Velocity on the Corrosion Behavior of Copper in Sodium Bicarbonate Solutions

Abstract The effect of ammonium chloride additions on the corrosion behavior of copper in 1 N sodium bicarbonate solutions has been characterized using a rotating ring-ring linear cyclic voltammetry technique. The experimentation and solution compositions used were selected to account for an unusually high incidence of pitting found to occur on interior surfaces of copper cold-water plumbing fixtures in the vicinity of neutral soldering flux residues. Although concentrations of ammonium chloride above 0.05 N were found to result in an increase of corrosion rate often attributed to the stabilization of a cuprous ion complex metal dissolution reaction product, under freely corroding conditions in an air-saturated solution, corrosion of copper metal would occur by an anodic process in which current was distributed between both soluble metal ions (cuprous and cupric ions) and insoluble corrosion product deposits. Although increases in applied potential or relative fluid velocity produced increases in the total corrosion rate, there was also a change in current distribution between the various components of the overall anodic process. Results from this study suggest that soluble and insoluble corrosion products (cathodically or anodically generated during a single linear polarization cycle) affect corrosion behavior during either successive cycles or extended exposure periods to such an extent that sole reliance on single-cycle anodic polarization behavior for the prediction of long-term corrosion resistance for copper and its alloys should be avoided.

Synthesis and secretion of the human vitamin B12-binding protein, transcobalamin II, by cultured skin fibroblasts and by bone marrow cells

Human skin fibroblasts and bone marrow cells were tested for their ability to synthesize the cobalamin-binding protein transcobalamin II. Cobalamin binders secreted in the media of cultured fibroblasts and of dextran-sedimented bone marrow cells in liquid culture could be identified as transcobalamin II on the basis of immunological, electrophoretical and chromatographical identity with serum transcobalamin II. The net secretion of transcobalamin II increased linearly with time of culture, up to 30 days after confluence. The reversible inhibition of transcobalamin II secretion by cycloheximide demonstrated that human fibroblasts are capable of de novo transcobalamin II synthesis. Addition of cyanocobalamin to the fibroblast culture medium induced a reduction of transcobalamin II net secretion, most likely due to preferred uptake of transcobalamin II saturated with cobalamin, as opposed to unsaturated protein. Addition of lysozymal enzyme inhibitors, ammonium chloride and chloroquine, resulted in a markedly increased secretion of transcobalamin II. In the culture medium of fibroblasts, obtained from two transcobalamin II-deficient patients, functionally deficient transcobalamin II was demonstrated on the basis of strongly reduced secretion of immunoreactive transcobalamin II, and the absence of apotranscobalamin II. Individual phenotypes in the culture media of the fibroblasts and bone marrow cells were identical to the corresponding serum transcobalamin II types.

Simultaneous nitrification and diffusion in soil. I. The effects of the addition of a low level of ammonium chloride

SUMMARYThe nitrification of NH4+ and the simultaneous diffusion of NH4+, NO3− and H+ following the addition of ammonium chloride to a fine sandy loam soil was analysed experimentally and theoretically. Experimentally, the concentration profiles of mineral N and pH were analysed 140h and 284 h after the homogeneous addition of 11 μmoles NH4Clcm−3 of soil to one part of a composite soil column. The mathematical model presented includes a kinetic model of nitrifier growth and activity, the adsorption equilibria of NH4+ and soil acidity with the soil solid phase and the influence of other ions on the diffusion characteristics of each diffusing ion. The predictions of the model were generated using parameters derived from independent experiments so that the predictions did not depend on data derived from the experimental concentration profiles. Good agreement was found between experimental and predicted profiles. The use of the model for predicting the penetration of NH4+ and NO3− into the soil is demonstrated.

Fermentation alcohol from grain sorghum starch

Grain sorghum is an attractive agricultural feedstock for ethanol production because of its high starch content and the fact that it is more drought-resistant than other cereal crops such as maize. The popular bird-proof grain sorghum variety was investigated. This was subjected to a chemical pretreatment to remove the polyphenolic compounds prior to starch hydrolysis and subsequent fermentation. Starch hydrolysis was accomplished with a commercial α-amylase for liquefaction and amyloglucosidase for saccharification. Depending on the saccharification conditions, the hydrolysate contained 65 to 128 g litre −1 glucose with corresponding maltose concentrations of 50 to 20 g litre −1. Several yeast strains were evaluated for their ability to ferment maltose. The total saccharification plus fermentation time could be shortened substantially by inoculating after a brief saccharification period. The addition of ammonium chloride to the hydrolysate improved the fermentation rate. From a 30% grain sorghum slurry an ethanol concentration of over 12% (v/v) was obtained, which was 84% of the theoretical maximum. The data indicated that about 380 litres of ethanol could be produced per ton grain sorghum.

Differential proliferative responses of cultured Schwann cells to axolemma- and myelin-enriched fractions. I. Biochemical studies.

Cultured rat Schwann cells were treated for 72 h with axolemma- and myelin-enriched fractions prepared from rat brainstem. [3H]Thymidine was added to the cultures 48 h before the termination of the experiment. Although, both fractions produced a dose-dependent uptake of label into Schwann cells, the shape of the dose response curves and rates at which [3H]thymidine was incorporated were different. The axolemma-enriched fraction produced a sigmoid dose response curve with a Hill coefficient of 2.05. The dose response curve for myelin rose sharply and saturated at a level that was approximately 50% of the maximal response observed with axolemma. Schwann cells that had been treated with axolemma exhibited little change in the rate of [3H]thymidine incorporation from 36-72 h after the addition of the membranes. In contrast, Schwann cells accumulated label three times faster during the 48-72-h period following the addition of myelin to the cultures when compared with the rate during the preceding 12-h interval. Furthermore, the mitogenic activity of the myelin-enriched fraction was decreased by the addition of ammonium chloride, a lysosomal inhibitor, whereas the activity of the axolemmal fraction was not impaired.

Uncoating of influenza virus in endosomes.

The intracellular uncoating site of influenza virus was studied by measuring the fluorescence intensity of probes conjugated to the virus or the isolated hemagglutinin and also by assaying virus replication under various incubation conditions. Acidification of the viral environment was monitored by the decrease in the fluorescence intensity of fluorescein isothiocyanate, and transport of the virus particles into secondary lysosomes was assayed by the increase in the fluorescence intensity of fluorescein isothiocyanate diphosphate. The intracellular pH was estimated by the ratio of fluorescence intensities excited at two different wavelengths. It was found that the viral environment became acidified to a pH value of 5.1 to 5.2 within 10 min at 37 degrees C or 1 h at 20 degrees C after endocytosis. Addition of ammonium chloride to the medium rapidly raised the pH to 6.7. Transport of the virus particles into the secondary lysosomes was slower and negligibly low during those incubation periods. Virus replication occurred when the cells were incubated for 10 min at 37 degrees C or for 1 h at 20 degrees C, followed by incubation in the presence of ammonium chloride for a total of 12 h. These results indicate the uncoating of influenza virus in endosomes before reaching the secondary lysosomes.

Magnesium absorption from the digestive tract of sheep.

Factors affecting absorption of Mg from the ovine rumen have been studied using either a pouch constructed from part of the dorsal rumen or by an isolated washed rumen technique in vivo. Net absorption of Mg against the prevailing electrochemical gradient was observed. An increase in the K/Na ratio within the rumen led to an increase in the potential difference across the rumen wall, blood positive, and to a decrease in the net efflux of Mg from the rumen. This decrease was due to an increase in Mg influx into the rumen. The addition of ammonium chloride (30 mmol/l) to the rumen contents also led to a reduction in net Mg absorption but to no significant change in potential difference. The effects of high K/Na ratio and high ammonium ion concentration within the rumen were additive in causing decreases in net effluxes of both Mg and Na. An inverse relationship was demonstrated between the Ca concentration in the rumen and the net absorption rate of Mg. It was concluded that the efflux of Mg across the rumen wall depends at least in part on a functional system for Na transport.

Iron uptake by mammalian cortical neurons

Although iron accumulates in the brain in a number of pathological conditions, including Hallervorden-Spatz syndrome, Parkinson's disease, and neurosyphilis, studies of brain iron metabolism have been performed only rarely. Neuronal-enriched cultures were prepared from fetal mouse brain. After 18 days the cells were exposed to radiolabeled iron. Total iron uptake and incorporation into ferritin were rapid and linear over four hours. The addition of either methylamine or ammonium chloride, both known blockers of transferrin-iron release through their lysosomotropic properties, inhibited total iron uptake. Methylamine also inhibited the rate of ferritin-iron incorporation, most likely by interfering with transferrin-iron release. The data suggest that neuronal iron transport, much like that in other mammalian tissues, is transferrin mediated and that blockers of transferrin-iron release may be of value in conditions in which there is brain iron overload.

Effect of inhibitors on nitrogenase regulation in the cyanobacterium Nostoc linckia

Summary The effects of ammonium ion and certain inhibitors of protein synthesis on nitrogenase activity in Nostoc linckia were compared during heterocyst induction and exponential phases. Early stages of heterocyst differentiation and nitrogenase induction are prone to ammonium inhibition. Nitrogenase activity continued to increase even in presence of ammonium in 36 h old cultures. Addition of ammonium chloride in exponential, nitrogen-dependent cultures had little effect on nitrogenase activity up to 16 h whereafter the activity fell. The heterocyst frequency was higher in rifampicin and lower in chloramphenicol, as compared to control cultures.

Récupération sélective du vanadium dans l'effluent d'un procédé de fabrication du blanc de titane

AbstractThe selective recovery of vanadium from an effluent of a manufacturing process for titanium white (oxide) has been made. The process retained is based on the partial neutralization of the effluent by means of calcium carbonate and on the separation of metal hydroxides from calcium sulfate and the solution. The hydroxides are thereafter calcined in the presence of a sodium salt, so that sodium vanadate may then be extracted by washing with water. Vanadium is finally precipitated by the addition of ammonium chloride or pH adjustment.The experimental results obtained in the laboratory study of the effluent neutralization, the calcination and leaching of the hydroxides and the vanadium precipitation are presented and discussed. The yields obtained in the various stages and their interdependance are also discussed.

Derepression of nitrogenase in chemostat cultures of the fast growing Rhizobium leguminosarum

Rhizobium leguminosarum is capable of nitrogen fixation in free living cultures. Nitrogenase activity can be induced when the ammonia supply of a nitrogen-limited culture, in which the oxygen concentration is regulated at 1 μm, is switched off. Assuming a nitrogen content of the cell of 12% the theoretical washout curve of such a culture can be calculated. The measured optical densities are higher than the calculated ones. In one case, 8 days after the shift, the medium supply was switched off and batch growth with molecular nitrogen occurred. Acetylene reduction started immediately in samples taken 2 days after the shift. Addition of ammonium chloride to the test vials inhibited acetylene reduction. The highest specific activities were found 5–8 days after the shift (100 nmol ethylene formed per milligram dry weight per hour). From this activity a μmax of 0.007–0.009 (generation time 76–98 h) on molecular nitrogen can be calculated. After the shift Ymannitol decreased from 33 to 23 in the first 48 h. Three days after the shift Ymannitol had a value of 15. During batch growth Ymannitol had a value of 8.

The inhibitive effect of extraneous ion addition on stress corrosion cracking of alpha-brass

The addition of ammonium chloride, cobalt sulphate, cesium sulphate and ethylene diamine to a Mattsson solution and the addition of ammonium sulphate to the Pugh solution have been found to produce an inhibitive effect on the stress corrosion cracking of alpha-brass in these solutions. Ammonium chloride and ammonium sulphate additions affect the tarnish formation on the specimen as well as the cracking pattern. Electrochemical polarization studies have also been carried out with these two additives. The observations have been explained in the light of adsorption of these ionic species at selected sites on the metal surface and their possible interference with the cathodic reactions.

Monensin inhibits Semliki Forest virus penetration into culture cells.

The carboxylic ionophores monensin and nigericin, at concentrations higher than 10 and 6 muM, respectively, prevent the penetration of the Semliki Forest virus (SFV) genome into the cytosol of baby hamster kidney (BHK-21) cells and thereby inhibit viral replication. In the absence of inhibitors, the entry of SFV is known to proceed by adsorptive endocytosis in coated vesicles, followed by acid-triggered membrane fusion in intracellular vacuoles or lysosomes. The results show that binding of the virus to the cell surface, adsorptive endocytosis, and intracellular transport of viruses to the lysosomes are only marginally affected by the ionophores. No direct virucidal effect is observed, nor is the membrane fusion activity of the virus at low pH directly affected. Sequential addition of monensin and ammonium chloride (a non-related lysosomotropic inhibitor of SFV entry) indicates that both inhibitors affect the same step in the entry pathway. On the basis of these data and the known effects of carboxylic ionophores and lysosomotropic weak bases on cellular pH gradients, we conclude that monensin inhibits penetration by increasing the pH in endocytic vacuoles and lysosomes above pH 6, which is the pH threshold for the viral membrane fusion activity.

Properties of Magnesium Oxides Prepared from Various Salts and Their Catalytic Activity in 1-Butene Isomerization

Abstract The basicity, one-electron donor property, and surface area were examined on the magnesium oxide catalysts prepared from six different kinds of magnesium salts. Magnesium oxide prepared from magnesium nitrate, oxalate, and acetate exhibited strong basicity and relatively large surface area and, on the other hand, MgO prepared from magnesium chloride, carbonate and sulfate had relatively weak basicity and small surface area. Number of one-electron donor centers hardly changed in the variety of magnesium oxides, except the one prepared from magnesium chloride. Magnesium oxide prepared from chloride showed both the lowest basicity with less strength than H−=15.0 and surface area in the six kinds of catalysts. In order to examine the influence of remaining anions in MgO a variety of catalysts were prepared by the addition of ammonium chloride, sulfate, and carbonate, respectively in MgO prepared from the nitrate. Ammonium chloride brought the greatest influence on the basicity, one-electron donor property, and surface area. Thus the remaining chloride ion greatly affected such properties as cited above. Sodium nitrite which decomposes at higher temperature than 320 °C was added to the magnesium oxides for the examination of the effect of the sodium cation. The amount of the basicity with a moderate strength (H−=15.0–22.3) increased by the addition of NaNO2. This was ascribed to the formation of the moderate strength of basicity by the interaction of Na2O, one of the decomposed products of NaNO2 and MgO. Isomerization of 1-butene was carried out on the six kinds of catalysts at 30 °C. The magnesium oxides prepared from nitrate, oxalate, and acetate salts (group A) exhibited isomerization activity and the ones from chloride, sulfate, and carbonate (group B) did not entirely. The isomerization activity could be correlated with the stronger basicity than H−=22.3. Temperature pregrammed desorption curves of acetic acid adsorbed on the catalysts indicated two peaks at around 350 and 420 °C in group A catalysts and only one at 350 °C in group B. The desorbed peak at around 420 °C was assigned to the adsorbed acetic acid on the stronger basic sites than H−=22.3.

The conductivity of aqueous zinc chloride solutions

The conductivity of aqueous zinc chloride reaches a maximum of 10.7 Ω−1 m−1 at 3.7 M ZnCl2. Measurements on chlorinated ZnCl2 showed that at low chlorine concentrations, the conductivity increased linearly with the square root of the chlorine concentration. The increase was due to the three species: dissolved chlorine, Cl 3 − and HClO. Ammonium chloride additions increased the conductivity of aqueous zinc chloride substantially.

Mechanism by which enhanced ammonia production reduces urinary potassium excretion

To determine the mechanism whereby an increase in ammonia production decreases urinary potassium excretion, we perfused isolated rat kidneys at a pH of either 7.0 or 7.4. After 45 min of perfusion at either pH, glutamine or ammonium chloride was added to the perfusate to result in concentration of 5 and 0.8 mM, respectively and observations were continued for 50 min. Control kidneys were perfused at both pH's without further additions to the perfusate. At pH 7.0 glutamine increased ammonia production and increased urinary ammonium excretion strikingly; whereas the addition of ammonium chloride did not change ammonia production but increased urinary ammonium excretion to a comparably degree. Both maneuvers resulted in a reciprocal fall in urinary potassium excretion in comparison with control perfusions. The decreases in potassium excretion could not be accounted for by differences in perfusate or urinary acid-base parameters, or by changes in urinary sodium, water, or chloride excretion. At pH 7.4, glutamine also significantly increased ammonia production and perfusate ammonia concentration. In contrast to the studied at pH 7.0 in which the urine pH was acid (5.9), the urine remained alkaline (pH 7.2), and both urinary ammonium excretion and urinary potassium excretion were unaltered. Thus, potassium sparing is not a nonspecific effect of glutamine, its metabolism to ammonia, or perfusate ammonia concentration but is directly related to an increase in urinary ammonium excretion.

Effects of methionine sulfoximine on cerebral ATPases

Hyperammonemia inducing drug, l-methionine- dl-sulfoximine (MSI), was administered to rats and the changes in the activities of Na +-ATPase and Mg 2+-ATPase were followed in three different brain regions. The activity of Mg 2+-ATPase decreased over the control, while that of Na 2+, K +-ATPase increased in all regions. The per cent increase was more in brain stem (BS) than in cerebral cortex (CC) and cerebellum (CE). In vitro addition of MSI and ammonium chloride also resulted in similar changes. These results indicate that MSI induced toxicity is not only due to inhibition of glutamine synthetase but also by stimulation of Na +, K +-ATPase leading to the depletion of cerebral ATP levels.