scholarly journals Sodium and Water Balance in the Cichlid Teleost, Tilapia Mossambica

1967 ◽  
Vol 47 (3) ◽  
pp. 461-470 ◽  
Author(s):  
W. T. W. POTTS ◽  
M. A. FOSTER ◽  
P. P. RUDY ◽  
G. PARRY HOWELLS
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
Tritiated Water ◽  
Sodium Influx ◽  
Water Drinking ◽  
Body Sodium ◽  
Total Body ◽  
Sodium And Water Balance ◽  
Total Sodium

1. The total body sodium increases from 45.9 µM/g. fish in fresh water to 59.9 µM/g. fish in 200 % sea water. 2. The rate of exchange of sodium increases from 2 µM/g./hr. in fresh water to 60 µM/g./hr. in 100% sea water. 3. The rate of drinking increases from 0.26%/hr. fresh water to 1.6%/hr. in 400% sea water. Even in 200% sea water drinking accounts for only a quarter of the total sodium influx. 4. The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water. The permeabilities to water measured in this way are consistent with the drinking rates determined in sea water and 200% sea water.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

Ionic Regulation of the Baltic and Fresh-Water Races of the Isopod Mesidotea (Saduria) Entomon (L.)

1968 ◽  
Vol 48 (1) ◽  
pp. 141-158 ◽  
Author(s):  
P. C. CROGHAN ◽  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
Relative Volume ◽  
Ice Age ◽  
Ionic Regulation ◽  
Sodium Influx ◽  
Active Uptake ◽  
Concentrated Solution ◽  
The Baltic

1. The isopod Mesidotea entomon has colonized the Baltic and certain Swedish lakes since the end of the last Ice Age. 2. The ionic regulation of Baltic animals and fresh-water animals (L. Mälaren) has been compared. 3. It has been possible to adapt Baltic animals to very dilute media, but 5% Askö sea water (5.5 mM/l. Na) appears to be the limit of adaptation. The haemolymph sodium concentration of Baltic animals from the very dilute media was considerably lowered. 4. The haemolymph sodium concentration in Mälaren animals is high (250 mM/l. Na) and comparable with that in Baltic animals in much more concentrated solution. The haemolymph ionic ratios of the Baltic and freshwater animals are similar. The Cl:Na ratio rises slightly in the more concentrated haemolymph samples. 5. From the concentration of ions in the haemolymph and in the total body water, the relative volume of the haemolymph was calculated. Mälaren animals appear to have a much larger haemolymph volume. 6. The permeability of the animals was determined from the rate of loss of sodium into de-ionized water. The permeability of the Mälaren animals is considerably reduced compared to the Baltic animals. Permeability is not related to the medium to which the animals had been adapted. 7. The sodium influx was determined using 22Na. The rate of active uptake was calculated from this. The maximal rate of active uptake was similar in Baltic and Mälaren animals. The sodium concentration of the medium at which active uptake was half maximum (KM) was considerably lower in Malaren animals than in Baltic animals. 8. The evolution of Mesidotea as a fresh-water animal is interpreted as a result of a reduction in permeability of the external surfaces to NaCl and an increase in the affinity of the active transport mechanism enabling the animal to maintain the haemolymph NaCl concentration in a steady state in fresh water.

Salt and Water Balance in Salmon Smolts

1970 ◽  
Vol 52 (3) ◽  
pp. 553-564
Author(s):  
W. T. W. POTTS ◽  
MARGARET A. FOSTER ◽  
J. W. STATHER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sodium Pump ◽  
Sea Water ◽  
High Rate ◽  
Exchange Diffusion ◽  
Rapid Changes ◽  
Alternative Hypotheses ◽  
Salt And Water Balance

1. Salmon smolts adapted to sea water maintain a high rate of turnover of both sodium and chloride, but when adapted to fresh water the rate of turnover is low. 2. Only a small part of the influx takes place through the gut. 3. On immediate transfer from sea water to dilute sea water or to fresh water the influxes decline rapidly, but on transfer from fresh water to sea water the restoration of the fluxes takes place slowly. 4. The alternative hypotheses that the rapid changes are due to exchange diffusion or to rapid adjustments of the sodium pump are discussed.

Free Amino Acid and Haemolymph Concentration Changes in Sphaeroma Rugicauda (Isopoda) During Adaptation to a Dilute Salinity

1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sea Water ◽  
Protein Nitrogen ◽  
Body Sodium ◽  
Concentration Changes ◽  
Total Body

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. 2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. 3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. 4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. 5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. 6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. 7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. 8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. 9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.

scholarly journals Regulation of Water and Some Ions in Gammarids (Amphipoda)

1971 ◽  
Vol 55 (2) ◽  
pp. 357-369
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Sodium Chloride ◽  
Sea Water ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Body Water ◽  
The Body ◽  
Salinity Range ◽  
Sodium Potassium ◽  
Body Sodium ◽  
Total Body

1. A comparison was made of the body water contents and the concentrations of sodium, potassium and chloride in the blood and body water of Gammarus zaddachi, G. locusta and Marinogammarus finmarchicus. 2. G. zaddachi had a slightly higher body water content than G. locusta and M. finmarchicus. 3. In all three species the blood chloride concentration was lower than the external chloride concentration in 80-113 % sea water, but the blood sodium concentration was equal to or slightly above the sodium concentration in the external medium. 4. The total body sodium concentration was always greater than the total body chloride concentration. In M.finmarchicus the ratio of body sodium/chloride increased from 1.2 to 1.3 over the salinity range 100-20% sea water. In G. zaddachi the ratio of body sodium/chloride increased from 1.08 at 100% sea water to 1.87 in 0.25 mM/l NaCl. 5. The total body potassium concentration remained constant. The potassium loss rate and the balance concentration were relatively high in G. zaddachi. 6. The porportion of body water in the blood space was calculated from the assumption that a Donnan equilibrium exists between chloride and potassium ions in the extracellular blood space and the intracellular space. In G. zaddachi the blood space was equivalent to 60% body H2O at 100% sea water, and equivalent to 50% body H2O at 40% sea water down to 0.5 mM/l NaCl. In M.finmarchicus the blood space was equivalent to 38-44% body H2O at salinities of 20-100% sea water. 7. The mean intracellular concentrations of sodium, potassium and chloride were also calculated. It was concluded that for each ion its intracellular concentration is much the same in the four euryhaline gammarids. The intracellular chloride concentration is roughly proportional to the blood chloride concentration. The intracellular sodium concentration is regulated in the face of large changes in the blood sodium concentration.

Approach to the patient with hypernatraemia

2018 ◽  
Author(s):  
Robert Zietse ◽  
Ewout Hoorn
Keyword(s):  
Water Balance ◽  
Arginine Vasopressin ◽  
Critically Ill Patients ◽  
Urine Osmolality ◽  
The Elderly ◽  
Brain Cells ◽  
Urine Sodium ◽  
Water Shift ◽  
Body Sodium ◽  
Total Body

Hypernatraemia is much less common than hyponatraemia, and its prevalence is higher in certain populations, including children, the elderly, and critically ill patients. A common feature is that patients affected have been unable to drink water to correct the disorder. Hyponatraemia and hypernatraemia are both primarily disorders of water balance. Hypernatraemia is caused by a relative deficit of total body water in comparison to total body sodium. Both disorders are often associated with disturbances in the hormone governing water balance, arginine vasopressin (antidiuretic hormone). Hypernatraemia may be due to an inability to secrete vasopressin or a resistance to its actions in the kidney. The diagnostic approach relies on the assessment of the time of development, symptoms, and volume status, along with laboratory parameters such as urine sodium and urine osmolality. If hypernatraemia develop acutely, treatment should be directed towards counteracting the water shift to or from brain cells. In more chronic cases, treatment should be directed to the underlying cause while avoiding overcorrection.

Preliminary Observations on the Ionic Regulation of the Arctic Char Salvelinus Alpinus

1971 ◽  
Vol 55 (1) ◽  
pp. 213-222
Author(s):  
R. A. ROBERTS
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Potassium Concentration ◽  
Salvelinus Alpinus ◽  
Sodium Concentration ◽  
Sodium Content ◽  
Arctic Char ◽  
The Arctic ◽  
High Degree ◽  
Total Sodium

1. The degree of euryhalinity in a fresh-water resident population of the arctic char, Salvelinus alpinus, has been determined. 2. Although isolated in fresh water for c. 10000-12000 years these fish still show a high degree of salinity tolerance characteristic of their ancestral stock, but this is variably developed in individuals. 3. In fresh water, blood sodium concentration is regulated at 150 mM/l and chloride at 130 mM/l. These increase to 233 and 218 mm/l respectively in sea water. 4. Fish in sea water show a large increase in muscle sodium, although the potassium concentration is only slightly higher than that maintained in fresh water. The total sodium content of the fish reflects the increase observed in the intracellular and extracellular compartments. 5. The rate of sodium turnover in sea-water-adapted fish is some ten times higher than in fresh-water-adapted fish, although it is significantly lower than that observed in most sea-water-adapted teleosts.

The role of environmental calcium in freshwater survival of the marine teleost, Lagodon rhomboides

1976 ◽  
Vol 65 (3) ◽  
pp. 529-538
Author(s):  
J. C. Carrier ◽  
D. H. Evans
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chelating Agent ◽  
Marine Teleost ◽  
Lagodon Rhomboides ◽  
Na Efflux ◽  
Total Body ◽  
Na Uptake ◽  
Marine Teleost Fish

(1) The marine teleost fish, Lagodon rhomboides, can only tolerate fresh water (5 mM Na) if Ca is also present (10 mM). Transfer to Ca-free fresh water is followed by a substantial increase in radioactive Na efflux with little or no change in the transepithelial potential. Addition of the chelating agent EDTA (2 mM) further increases Na efflux. Fish left in Ca-free fresh water for 2-5 h die with a total body Na less than 50% of that found in animals acclimated to Ca-supplemented fresh water. (2) Rates of Na uptake were measured on either sea-water-acclimated or Ca-supplemented fresh water-acclimated fish transferred to various low Na media. In both cases Na uptake has a high Km, is saturable, inhibited by external NH4, H and amiloride, and is not related to changes in the trans-epithelial potential. (3) It is suggested that L. rhomboides is dependent upon external Ca to decrease diffusional Na loss in low salinities so that a relatively inefficient Na uptake can balance diffusional and urinary Na loss.

Regulation of Water and Some Ions in Gammarids (Amphipoda)

1971 ◽  
Vol 55 (2) ◽  
pp. 345-355
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Water Content ◽  
Sea Water ◽  
Potassium Concentration ◽  
Body Water ◽  
The Body ◽  
Sodium Potassium ◽  
Intracellular Space ◽  
Body Sodium ◽  
The Mean ◽  
Total Body

1. The water content, and the concentrations of sodium potassium and chloride in the blood and body water were determined in Gammarus pulex acclimatized to external salinities ranging from 0.06 mM/l NaCl up to 50 % sea water. 2. The mean body water content remained constant at 79.0-80.3 % body wet weight. The total body sodium and chloride concentrations were lowered in 0.06 mM/l NaCl and increased markedly at salinities above 10% sea water. The normal ratio of body sodium/chloride was 1.45-1.70, decreasing to 1.0 at 50% sea water. 3. The total body potassium concentration remained constant at 47.5-55.2 mM/kg body H2O. The rate of potassium loss across the body surface was relatively fast. Potassium balance was maintained at an external potassium concentration of 0.005 mM/l by starved animals, and at 0.005 mM/l by fed animals. 4. The proportion of body water in the blood space was calculated from the concentrations of potassium and chloride in the blood and in the body water. The blood space contained 38-42% body H2O in animals from fresh water. The blood space decreased to 31 % body H2O in animals from 0.06 mM/l NaCl. The sodium space was equivalent to about 70 % body H2O. 5. The mean intracellular concentrations of sodium, potassium and chloride were estimated and the results were compared with previous analyses made on the tissues of G. pulex and other crustaceans. It was concluded that in G. pulex from fresh water the distribution of potassium and chloride ions between the extracellular blood space and the intracellular space approximately conforms to a Donnan equilibrium. 30-40% of the body sodium is apparently located in the intracellular space.

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