Branchial Sodium Exchange and Ammonia Excretion in the Goldfish Carassius Auratus. Effects of Ammonia-Loading and Temperature Changes

1972 ◽  
Vol 56 (3) ◽  
pp. 601-620 ◽  
Author(s):  
J. MAETZ

1. Sodium influx and efflux and ammonia excretion by the gill have been studied as a function of external sodium chloride concentration in Carassius auratus before and after loading the fish with ammonia. 2. No correlation between net sodium uptake and ammonia excretion is observed, either when the net uptake changes with an external sodium change or when net uptake increases with ammonia-loading. Branchial handling of chlroide ions cannot explain this absence of correlation. 3. Comparison of the concentrations of free base ammonia (NH3) and of ammonium ions (NH4+) in both (dorsal aorta) and external medium at the end of the closed-circuit experiments on control or ammonia-loaded fish demonstrates that the gill is permeable to the ionized form of ammonia. 4. An abrupt temperature decrease (16 → 6 °C) affects the sodium influx (Q10 = 3) much more than the sodium efflux (Q10 = 1.7). Sodium balance becomes negative unless the fish is ammonia-loaded. The observed effects of temperature are reversible when the fish is returned to 16 °C. Branchial ammonia excretion is highly temperature-sensitive (Q10 = 4) in control fish when metabolic production limits ammonia excretion. After ammonia-loading, when most of the ammonia cleared by the gill is exogenous, the effect of temperature on branchial permeability to ammonia (Q10 = 1.9) suggests a passive transfer of ammonium ions. 5. The contributors of the kidney and the gill in sodium loss and ammonia excretion are compared in intact and ammonia-loaded fish.

1964 ◽  
Vol 47 (6) ◽  
pp. 1209-1227 ◽  
Author(s):  
J. Maetz ◽  
F. García Romeu

The addition of ammonium ions to the external medium results in an inhibition of the sodium influx and net uptake in Carassius auratus, while intraperitoneal injection of ammonium produces the opposite effect. The simultaneous chloride balance is not significantly affected by these treatments. The addition of bicarbonate ions to the external medium results in a reduction of the influx and net flux of chloride, while injection of bicarbonate produces the opposite effect. The simultaneous sodium balance is not significantly altered. The effects of the external additions are reversible after elimination of the excess ammonium or bicarbonate ions by rinsing. Inhibition of carbonic anhydrase in the gill by injection of acetazoleamide produces a simultaneous inhibition of both sodium and chloride exchanges. These results confirm the hypothesis of an exchange of sodium for ammonium, and of bicarbonate for chloride across the gill. A tentative schematic representation of the ionic absorption mechanisms in the branchial cell of the fresh-water teleosts is given. Similarities with other biological membranes and especially with the renal tubule are pointed out.


1973 ◽  
Vol 58 (2) ◽  
pp. 487-502
Author(s):  
P. PAYAN

1. Branchial sodium exchanges were measured with the help of 24Na in the marine elasmobranch Scyliorhinus canicula. Handling causes a transient increase of the sodium influx and decrease of the sodium efflux in both intact and hypophysectomized fish. 2. Ammonia-loading (300 µ-equiv./100 g) is followed by an increase of both influx and efflux of sodium resulting in an augmented net sodium uptake lasting for at least 4 h. Ammonia excretion is also increased but only for 2 h. Ammonia-loading results in a metabolic acidosis lasting for at least 4 h. 3. HCl injection (100 µ-equiv./100 g) produces an increase of both influx and efflux of sodium resulting in an augmented net sodium uptake lasting for at least 4 h. Ammonia excretion is not affected. 4. Acetazolamide injection (10 mg/100 g) results in a depression of the sodium influx, while the sodium efflux remains unchanged. This inhibitory effect is observed in control fish as well as in fish treated with HCl or ammonium salt injections. 5. These observations confirm that the gill plays a major role in the maintenance of the pH of the body fluids. The similarities between the sodium transport mechanisms of Scyliorhinus and of the freshwater teleosts are emphasized. These results suggest that living elasmobranchs may have retained branchial mechanisms inherited from their freshwater ancestors.


1965 ◽  
Vol 42 (1) ◽  
pp. 29-43 ◽  
Author(s):  
R. H. STOBBART

1. Starved 4th-instar larvae of Aädes aegypti, when put into deionized water at a density of ten larvae/20 ml., are able to achieve sodium balance at the low external concentration of 5µM Na/l. 2. The balancing process involves a 10% drop in total sodium content, a more or less complete activation of the mechanism for sodium transport, and a reduction in the permeability of the larva to sodium as measured by the net sodium loss into deionized water. It is very probable that most of this reduction occurs in the anal papillae. 3. The relationship between external sodium concentration and sodium influx in larvae previously ‘balanced’ in deionized water is described approximately by the Michaelis equation. The sodium outflux also increases with increasing external sodium concentrations. 4. The net uptake of sodium by ‘balanced larvae’ appears to be significantly greater from solutions of NaCl than from solutions of NaNO3 NaHCO3 and Na2SO4. 5. The ions K+ Ca++ Mg++ and NH4+ when present as chlorides stimulate the influx of sodium from 0.1 mM/l. sodium chloride. When present as nitrates or sulphates they either have no effect or cause an inhibition of influx. 6. The results in 4 and 5 suggest that movements of chloride may be important in sodium uptake, and chloride uptake has been found to occur independently of sodium uptake. Measurements of potential difference between haemolymph and medium demonstrate active transport of both sodium and chloride.


1985 ◽  
Vol 223 (1233) ◽  
pp. 449-457 ◽  

A study has been made with human red cells of sodium movements that are sensitive to the drug furosemide. The aim was to see if furosemide-sensitive movements that are symmetrical (exchange) became asymmetrical (net transport) on replacement of chloride with nitrate as the major external anion. Cells were incubated for 4 h at 37 °C with 140 mm sodium, and chloride or nitrate as the principal anion. Under a variety of conditions (presence and absence of ouabain or furosemide, or both) the cell sodium concentration was always higher when chloride was replaced with nitrate. The cells became leakier to sodium. Tracer studies indicated that, in contrast to the results in chloride medium, the decrease in sodium influx was greater than the fall in efflux when furosemide was added to cells in nitrate medium. The results confirm that the sensitivity of sodium efflux to furosemide depended on chloride. However, influx showed a different sensitivity in that furosemide still inhibited in cells incubated in nitrate medium. The stimulation of sodium influx with nitrate medium was independent of external potassium (10–50 mm) and the furosemide-sensitive influx was also constant. It is concluded that symmetrical transmembrane sodium movements with cells in chloride medium became downhill asymmetrical in nitrate medium, giving a net gain of cell sodium that was insensitive to ouabain and sensitive to furosemide. The drug thus partly retarded the gain of cell sodium that otherwise occurred in the somewhat leaky cells.


1970 ◽  
Vol 53 (1) ◽  
pp. 75-92
Author(s):  
RALPH I. SMITH

1. N. diversicolor from estuarine conditions in north-eastern England can be adapted to a chloride concentration in a pond water (PW) medium at least as low as 0.9 mM/l, and shows a net uptake of chloride when returned to a medium 3-10 mM/l more concentrated. But in comparable transfers after adaptation at a chloride concentration of 10 mM/l, net uptake is not measurable. 2. Net uptake of chloride is demonstrable in the lowest salinities, where coelomic chloride concentration drops below the regulatory plateau. Net uptake reaches 3.5 µM/g wet weight/h. 3. Chloride loss is well correlated with weight loss after adaptation in 10 mM/l, but poorly so after adaptation in PW, suggesting that the urine is very hypotonic to body fluid in PW, and isotonic (or less hypotonic) at environmental chloride concentrations of 10 mM/l or higher. 4. Uptake of chloride occurs against both electrical and chemical-concentration gradients over the lower third of the environmental salinity range, which is the range in which hyperosmotic and hyperionic regulation are most pronounced. 5. The electrical potential across the body wall is maximal in PW (17 mV, inside-negative), and decreases to zero in 50 % SW. 6. Chloride influx (as measured with 36Cl) is highest in SW, and decreases in proportion to chloride concentration down to 50-25% SW, rises to a secondary maximum in 10% SW or less, and decreases as fresh water is approached. 7. Urinary chloride loss is low, and proportional to external chloride concentration in higher salinities, maximal in the c. 10% SW range of salinities, and apparently decreases to a minimum in FW. This may be in part the consequence of recovery of chloride from an hypotonic urine, in part the consequence of a reduction in urine volume. Evidence for these last two possibilities will be given in the papers which follow.


1970 ◽  
Vol 53 (1) ◽  
pp. 147-163 ◽  
Author(s):  
PETER GREENAWAY

1. Sodium regulation in normal, sodium-depleted and blood-depleted snails has been investigated. 2. Limnaea stagnalis has a sodium uptake mechanism with a high affinity for sodium ions, near maximum influx occurring in external sodium concentrations of 1.5-2 mM-Na/l and half maximum influx at 0.25 mM-Na/l. 3. L. stagnalis can maintain sodium balance in media containing 0.025 mM-Na/l. Adaptation to this concentration is achieved mainly by an increased rate of sodium uptake and a fall of 37 % in blood sodium concentration, but also by a reduction of the sodium loss rate and a decrease in blood volume. 4. A loss of 23% of total body sodium is necessary to stimulate increased sodium uptake. This loss causes near maximal stimulation of the sodium uptake mechanism. 5. An experimentally induced reduction of blood volume in L. stagnalis increases sodium uptake to three times the normal level. 6. About 40% of sodium influx from artificial tap water containing 0.35 mM-Na/l into normal snails is due to an exchange component. Similar exchange components of sodium influx were also observed in sodium-depleted and blood-depleted snails in the same external sodium concentration.


2018 ◽  
Vol 16 (2) ◽  
pp. 124 ◽  
Author(s):  
Asep Bayu Dani Nandiyanto ◽  
Heli Siti Halimatul Munawaroh ◽  
Tedi Kurniawan ◽  
Ahmad Mudzakir

The purpose of this study was to investigate influences of temperature on the conversion of ammonium tungstate pentahydrate (ATP) powder to tungsten trioxide (WO3) particles with controllable sizes, crystallinities, and physicochemical properties. In this study, we used a simple thermal decomposition method. In the experimental procedure, we explored the effect of temperature on the physicochemical properties of ATP by testing various heating temperatures (from 100 to 900 °C). The heated ATP samples were then characterized by a physical observation (i.e. color) and various analysis methods (i.e. a thermal gravimetric and differential thermal analysis, infrared spectroscopy, an X-ray diffraction, and a scanning electron microscope). Experimental results showed that increases in temperature had an impact to the decreases in particle size, the change in material crystallinity, and the change in physical properties (e.g. change of color from white, orange, to yellowish green). The relationships between the reaction temperatures and the physicochemical properties of the ATP were also investigated in detail along with the theoretical consideration and the proposal of the WO3 particle formation mechanism. In simplification, the phenomena can be described into three zones of temperatures. (1) Below 250 °C (release of water molecules and some ammonium ions).; (2) At 250-400 °C (release of water molecules and ammonium ions, restructurization of tungsten and oxygen elements, and formation of amorphous tungsten trioxide). (3) At higher than 400 °C (crystallization of tungsten trioxide). Since ATP possessed reactivity on temperature, its physicochemical properties changing could be observed easily, and the experimental procedure could be done easily. The present study will benefit not only for “chemistry and material science” but also potentially to be used as a model material for explaining the thermal behavior of material to undergraduate students (suitable used for a class and laboratory experiment and demonstration).


2016 ◽  
Vol 13 (2) ◽  
pp. 58-65
Author(s):  
Baghdad Science Journal

In this research local wheat peel was used as an adsorbent surface for removal of Azure B (AB) dye from the aqueous solution. The adsorption process was performed at different experimental parameters, equilibrium time, temperature, ionic strength and solution pH. The isotherms of adsorption are of H-type as compared with Giles curves and the adsorption data were coincide with Freundlich equation. The adsorption kinetic data were analyzed using pseudo- first and second order kinetic models. The effect of temperature was studied and the amount of dye adsorbed was found to increase with the increasing of temperature from 25 to 50 oC. The values of thermodynamic functions like enthalpy and entropy have been estimated. The quantity of adsorbed dye on the wheat peel increase according to the sequence follows: pH 9.3? 8 ? 7 ?6 ?5.2.The adsorption phenomenon is influenced by the sodium chloride concentration of solution. The obtained data refer to a decrease in amount of Azure B adsorbed in the existence of electrolyte.


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