The Involvement of Sodium Transport in the Volume Regulation of the Amphipod Crustacean, Gammarus Duebeni

1970 ◽  
Vol 53 (3) ◽  
pp. 737-751
Author(s):  
A. P. M. LOCKWOOD
Keyword(s):  
Blood Concentration ◽  
Volume Regulation ◽  
Evolutionary Significance ◽  
Fluid Loss ◽  
Body Volume ◽  
Transport Mechanisms ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Subsequent Decrease ◽  
Amphipod Crustacean

1. The effect on sodium influx of reduction in the fluid volume of the amphipod Gammarus duebeni has been investigated. 2. Removal of water and sodium by exposure to isotonic sucrose or mannitol results in no significant change in blood concentration but is followed subsequently by a marked increase in sodium influx. 3. The increased influx is due, at least in part, to increased active uptake of sodium. 4. Physical removal of blood by pipette stimulates a greater degree of increased uptake in some individuals by comparison with the controls. For technical reasons the increases as measured are smaller than in §2 above and in some individuals there is no response. 5. When the blood concentration is caused to rise at the same time as body volume is reduced there is subsequent decrease in sodium influx. 6. It is concluded that a mechanism is present which initiates an increase in sodium uptake on reduction of blood volume. This mechanism may be of value in replacing fluid loss resulting from haemorrhage, if water uptake accompanies sodium uptake. 7. The evolutionary significance of such a mechanism is discussed in relation to development of active transport mechanisms in present-day freshwater and brackish-water forms.

Branchial Sodium Transport Mechanisms in Scyliorhinus Canicula: Evidence for Na+/NH4+ and Na+ H+ Exchanges and for A Role of Carbonic Anhydrase

1973 ◽  
Vol 58 (2) ◽  
pp. 487-502
Author(s):  
P. PAYAN
Keyword(s):  
Sodium Transport ◽  
Ammonia Excretion ◽  
Inhibitory Effect ◽  
The Body ◽  
Control Fish ◽  
Transport Mechanisms ◽  
Sodium Influx ◽  
Sodium Efflux ◽  
Sodium Uptake ◽  
Scyliorhinus Canicula

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.

Sodium Regulation in the Freshwater Mollusc Limnaea Stagnalis (L.) (Gastropoda: Pulmonata)

1970 ◽  
Vol 53 (1) ◽  
pp. 147-163 ◽  
Author(s):  
PETER GREENAWAY
Keyword(s):  
Blood Volume ◽  
Tap Water ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Limnaea Stagnalis ◽  
Total Body ◽  
Sodium Regulation

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.

The Water Balance of a Serpulid Polychaete, Mercierella Enigmatica (Fauvel)

1974 ◽  
Vol 60 (2) ◽  
pp. 321-330
Author(s):  
HELEN LE B. SKAER
Keyword(s):  
Body Weight ◽  
Water Balance ◽  
Blood Volume ◽  
Blood Concentration ◽  
Volume Regulation ◽  
Sea Water ◽  
External Medium ◽  
Wide Range ◽  
Natural Range ◽  
Passive Movements

1. The serpulid polychaete Mercierella enigmatica is found naturally in a wide range of salinities - from fresh water to 150% sea water (< 1-55‰ < 25.8-1421 mOsm). 2. Changes in body weight, blood volume and blood osmolality have been measured both during and after equilibration of animals with media of altered salinity. 3. The blood remains similar in osmolality to the external medium over a very wide range of salinity (43-1620 mOsm); osmoregulation occurs only at the lowest limit of the natural range. 4. Mercierella enigmatica shows volume regulation; after 4 days of equilibration with a medium of altered salinity the blood volume shows much less change than the blood concentration. 5. During equilibration there appear to be passive movements of both water and salts between the animals and their environment.

scholarly journals The Effect of External Sodium and Calcium Concentrations on Sodium Fluxes by Salt-Depleted and Non-Depleted Minnows, Phoxinus Phoxinus (L.)

1987 ◽  
Vol 131 (1) ◽  
pp. 417-425
Author(s):  
W. J. FRAIN
Keyword(s):  
Sodium Concentration ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Efflux ◽  
Sodium Uptake ◽  
Km Value ◽  
Concentration Changes ◽  
The Relationship ◽  
Very High ◽  
External Calcium

The relationship between sodium influx and external sodium concentration in Phoxinus is complex and unusual. In non-depleted fish the relationship is approximately that given by the Michaelis-Menten equation of enzyme kinetics. However, the Km value (a measure of the affinity of the sodium uptake mechanism for sodium) is very high (3mmoll−1), indicating a low affinity of the uptake mechanism for sodium. On sodium depletion, the relationship between sodium influx and external sodium concentration changes to produce a curve which has a stepped appearance, and is unusual in that the maximum influx is not increased above that in non-depleted fish. The overall Km alters very little; however, the Km for the lower part of the curve is very low (0.05 mmoll−1). A model is proposed to explain these results in the form of two sodium uptake mechanisms working in parallel across the gill. The second carrier is only active when the fish is sodium-depleted and kept in low external sodium concentrations. Neither the external sodium concentration nor the external calcium concentration has any direct effect on sodium efflux. However, fish depleted in 1 mmoll−1 calcium have a lower sodium efflux than fish depleted in distilled water. Calcium appears to reduce the permeability of the gill to ions such as sodium. Since calcium has no effect on sodium influx, changes in gill permeability do not involve the sodium influxmechanism.

Sodium Regulation in the Fresh-Water Amphipod, Gammarus Pulex (L.)

1967 ◽  
Vol 46 (3) ◽  
pp. 499-518
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Loss Rate ◽  
Sodium Concentration ◽  
The Body ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Sodium Loss ◽  
Total Sodium

1. Sodium influx and loss rates in Gammarus pulex were measured at constant temperatures. The sodium loss rate was immediately influenced by a change in temperature, with a Q10 of 1.5 to 2.0 at temperatures between 0.3 and 21.5° C. The sodium influx rate is apparently influenced in the same way. 2. The sodium uptake mechanism in G. pulex from three localities was half-saturated at an external concentration of 0.10-0.15 mM/l. sodium. 3. The total sodium loss rate remained approximately constant in animals acclimatized to the range of external concentrations from 2 to about 0.2 mM/l. sodium. 18% of the sodium was lost in urine with a sodium concentration estimated at 30-50 mM/l. The remainder of the sodium loss was due to diffusion across the body surface. 4. In animals acclimatized to concentrations below about 0.2 mM/l. sodium the sodium loss rate was reduced, due to (a) a lower diffusion rate following a fall in the blood sodium concentration, and (b) the elaboration of a more dilute urine. 5. There was a very close association between changes in the blood sodium concentration, the elaboration of a very dilute urine, and the rate of sodium uptake at the body surface. The results indicate that a fall in the blood sodium concentration leads to simultaneous activation of the sodium uptake mechanisms at the body surface and in the antennary glands. 6. It is estimated that, by producing a dilute urine, total sodium uptake in G. pulex is shared equally between the renal uptake mechanism and the mechanism situated at the body surface. 7. In sea-water media G. pulex drinks and expels fluid from the gut. In a medium slightly hyperosmotic to the normal blood concentration the amount imbibed was equal to the normal rate of urine flow when in fresh water.

scholarly journals ACTIVE SODIUM UPTAKE BY THE TOAD AND ITS RESPONSE TO THE ANTIDIURETIC HORMONE

1955 ◽  
Vol 38 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Sumner M. Kalman ◽  
Hans H. Ussing
Keyword(s):  
Frog Skin ◽  
Bathing Solution ◽  
Active Sodium ◽  
Sodium Influx ◽  
Skin Potential ◽  
Pronounced Increase ◽  
Sodium Uptake ◽  
Potentiometric Measurements ◽  
And Control ◽  
Apparent Influence

A method has been described in which sodium uptake may be studied in the intact, anesthetized toad. Sodium uptake is determined by "counting" the whole animal in a special chamber after suspending it in a frog Ringer bath containing radioactive Na24. The effects of subcutaneous injection of the neurohypophyseal antidiuretic factor were studied with these results: 1. There was a pronounced increase in sodium influx following treatment with the hormone. 2. Sodium outflux was small in both experimental and control animals. 3. There was an increase in water uptake in both experimental and control animals after 1 hour in the bathing solution. This increase was greater in the experimental toads in which it is believed to be related, at least in part, to sodium transport. 4. Potentiometric measurements were made on the skin membrane potential of the whole animal while suspended in bathing solutions. These results were in essential agreement with those found for isolated frog skin. However, there was no apparent influence of the antidiuretic factor on the skin potential.

scholarly journals Comparison of Photassium and Sodium Uptake by Barley Roots at High and Low Salt Status

1968 ◽  
Vol 21 (5) ◽  
pp. 871 ◽  
Author(s):  
MG Pitman ◽  
AC Courtice ◽  
Barbara Lee
Keyword(s):  
Sodium Influx ◽  
Sodium Uptake ◽  
Low Salt ◽  
Net Uptake ◽  
Sodium And Potassium

Measurements are described of the uptake of sodium and potassium by barley roots at low salt status. It was found that initially there was little preference for potassium in the salt accumulated, but about 5 hr after the start of salt accumula� tion net uptake of sodium decreased markedly, and thereafter much more potassium was taken up than sodium. The roots reached salt saturation in about 24 hr. The decreased sodium uptake was due to a reduction in sodium influx.

The effect of enternal sodium concentration upon sodium fluxes in Chironomus dorsalis (Meig.) and Camptochironomus tentans (Fabr.), and the effect of other ions on sodium influx in C. tentans

1975 ◽  
Vol 62 (1) ◽  
pp. 141-155
Author(s):  
DA Wright
Keyword(s):  
Steady State ◽  
Sodium Concentration ◽  
Fourth Instar ◽  
Half Maximum ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Low Concentrations ◽  
Salt Depletion

In comparison with other freshwater animals, the sodium uptake mechanism in fourth instar larvae of both C. tentans and C. dorsalis has a moderate affinity for sodium. In both species half maximum influx (Km) occurs at about 0.57 mM-Na+ and is unaltered by salt depletion. Maximum influx is achieved in steady-state C. tentans at 1.9 mM-Na+, and in steady-state C. dorsalis at 3.0 mM-Na+. Both of these values increase on depletion. Efflux also appears to be saturable at higher external sodium concentrations. In C. tentans, sodium may be transported independently of chloride, although it seems likely that sodium movement is enhanced by chloride. Sulphate strongly inhibits sodium influx. Nitrate apparently inhibits sodium influx at low concentrations, but this inhibition is progressively overcome at external sodium concentrations approaching 4 mM. A number of cations interfere with sodium influx in depleted C. tentans, notably H+, Li+ and, to a lesser extent NH4+. It is suggested that these ions compete with sodium for carrier sites. Potassium is apparently transported independently of sodium.

Active Transport and Sodium Fluxes at Moult in the Amphipod, Gammarus Duebeni

1969 ◽  
Vol 51 (3) ◽  
pp. 591-605
Author(s):  
A. P. M. LOCKWOOD ◽  
W. R. H. ANDREWS
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Major Part ◽  
Sea Water ◽  
Sucrose Solution ◽  
The Body ◽  
Active Sodium ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
High Level

1. The sodium fluxes of individual Gammarus duebeni, which moulted in sea water, have been followed daily from the morning following moult for at least 6 days. 2. Sodium influx from sea water declined from 15.1µM/animal/hr. on the first morning after moult to 1.7µM/animal/hr. by the tenth day after moult. 3. Sodium influx from 10 mM/l. NaCl plus sucrose solution isotonic with sea water declines from 4.48µM/animal/hr. to 0.14µM/animal/hr. in inter-moult animals. 4. Thionine inhibits over 90% of the influx from 10 mM/l NaCl plus isotonic sucrose on the first day after moult, and this, together with other evidence, suggests that the major part of the influx from this medium is due to active sodium uptake. The rate of active uptake is comparable with, or faster than, the rate of uptake by animals acclimatized to fresh water. 5. The influx occurs primarily across the body surface. It is suggested that the high level of sodium uptake is associated with the water uptake which occurs at moult.

The Effect of Some Anions and Cations Upon the Fluxes and Net Uptake of Sodium in the Larva of Aedes Aegypti (L)

1965 ◽  
Vol 42 (1) ◽  
pp. 29-43 ◽  
Author(s):  
R. H. STOBBART
Keyword(s):  
Sodium Concentration ◽  
Sodium Content ◽  
Deionized Water ◽  
Sodium Balance ◽  
Sodium Influx ◽  
Sodium Uptake ◽  
Chloride Uptake ◽  
Net Uptake ◽  
The Relationship ◽  
Anal Papillae

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.

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