Sodium regulation in the larvae of Chironomus dorsalis (Meig.) and Camptochironomus tentans (Fabr.): the effect of slat depletion and some observations on temperature changes

1975 ◽  
Vol 62 (1) ◽  
pp. 121-139
Author(s):  
DA Wright
Keyword(s):  
Surrounding Medium ◽  
The Body ◽  
Sodium Balance ◽  
Primary Role ◽  
Secondary Importance ◽  
Temperature Changes ◽  
Body Sodium ◽  
Total Body ◽  
Sodium Regulation ◽  
Anal Papillae

Sodium regulation was studied in fourth instar larvae of Chironomus dorsalis and Camptochironomus tentans. Both maintain a body sodium level well above that of the surrounding medium. The haemolymph contains approximately 90% of total body sodium and approximates to a single compartment freely exchanging sodium with the external medium. The anal papillae play a primary role in sodium regulation, the gut being in secondary importance. Sodium regulation in both species is comparatively insensitive to alterations in acclimatization temperature. C. dorsalis and C. tentans are capable of maintaining sodium balance in media containing 10 mumole Na and 25 mumole Na respectively. When exposed to several changes of distilled water, C. tentansis capable of reducing sodium loss by elaboration of a more dilute urine. This is apparently,supplemented by a reduction in the permeability of the body surface. Activation of sodium uptake in both species is comparatively sluggish, with influx reaching a maximum only after the loss of greater than 30% body sodium.

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.

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.

Sodium Regulation and Adaptation to Fresh Water in the Isopod Genus Asellus

1974 ◽  
Vol 61 (3) ◽  
pp. 719-736
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
The Body ◽  
Sodium Balance ◽  
Short History ◽  
Sodium Influx ◽  
Km Value ◽  
Sodium Regulation ◽  
Natural Series ◽  
Total Concentrations

1. The principal features of the sodium regulatory mechanism are compared in Asellus communis Say, A. aquaticus (L.) and A. meridianus Rac. 2. Water content and total concentrations of sodium and chloride are similar in the three species, but they differ with respect to values for Kmax, Km, the loss rate, and the minimum sodium balance concentration. 3. It is suggested that A. meridianus, A. aquaticus and A. communis represent a natural series of increasing adaptation to fresh water. A. communis from North America is completely adapted to fresh water. It has the lowest loss rate, the lowest maximum saturation level (Kmax) for sodium influx, and the highest affinity (low Km value) for sodium ions in the transporting system at the body surface. In many respects A. meridianus resembles freshwater populations of Mesidotea entomon and Gammarus duebeni, and may therefore have had a relatively short history in fresh water.

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.

scholarly journals Low-Dose Nitric Oxide Inhibition Produces a Negative Sodium Balance in Conscious Dogs

2001 ◽  
Vol 12 (6) ◽  
pp. 1128-1136
Author(s):  
ERDMANN SEELIGER ◽  
PONTUS B. PERSSON ◽  
WILLEHAD BOEMKE ◽  
GÖTZ MOLLENHAUER ◽  
BENNO NAFZ ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Time Course ◽  
Low Dose ◽  
Plasma Renin ◽  
Renal Perfusion ◽  
Pressure Effects ◽  
Sodium Balance ◽  
Body Sodium ◽  
Natriuretic Effect ◽  
Total Body

Abstract. Nitric oxide modulates renal hemodynamics and salt and water handling. Studies on the latter have provided conflicting results, however. Electrolyte and water balances were therefore studied in 28 beagles for 4 d, to determine the various effects of nitric oxide synthase (NOS) inhibition on renal function. The dogs were chronically equipped with aortic occluders to reduce renal perfusion pressure (RPP), bladder catheters, and catheters for measurements of RPP and mean arterial BP. A swivel system allowed free movement within the kennels. In a first set of experiments, a nonpressor dose of L-Nω-nitroarginine (LN) (3 μg/min per kg body wt) was administered, to prevent increases in mean arterial BP and thus pressure effects on renin release and natriuresis. Remarkably, the nonpressor dose of LN caused a negative sodium balance. The natriuretic effect may involve reduced plasma renin activity, reduced aldosterone concentrations, and increased atrial natriuretic peptide concentrations. Changes in aldosterone levels, however, were the only parameters to parallel the time course of sodium excretion. In a second set of experiments, a sodium-retaining challenge was elicited by reduction of RPP. Dogs without NOS inhibition escaped sodium retention during RPP reduction after 2 d (“pressure escape”). LN neither ameliorated nor aggravated the sodium-retaining effect of reduced RPP, nor did it compromise the accomplishment of pressure escape. In conclusion, inhibition of NOS with a low dose of LN results in a reduction of total-body sodium. This effect mainly relies on reduced aldosterone concentrations. Furthermore, LN does not change the regulatory response to long-term RPP reduction.

Sodium Regulation in the Crayfish Astacus Fluviatilis

1960 ◽  
Vol 37 (1) ◽  
pp. 113-128
Author(s):  
G. W. BRYAN
Keyword(s):  
Tap Water ◽  
Sodium Concentration ◽  
The Body ◽  
Sodium Balance ◽  
Urine Sodium ◽  
Urine Concentrations ◽  
High Concentrations ◽  
Astacus Fluviatilis ◽  
Sodium Regulation ◽  
Simple Proportion

1. In external sodium concentrations of up to 100 mM./l. the blood sodium concentration of Astacus is only slightly increased. As the external level approaches or exceeds the normal blood sodium concentration of 200 mM./l. so the increase becomes more marked. Similarly, there is an increase in urine sodium concentration. This net gain of sodium is accompanied by a considerable rise in sodium outflux as shown by 22Na. At external concentrations exceeding 300 mM./l., blood and urine concentrations rise to a similar level and active sodium movements appear to cease. 2. With increased blood sodium concentration the level in the muscles rises also. This relationship is not one of simple proportion and at high concentrations there is relatively more sodium in the muscles. 3. In artificial tap water animals with a high blood concentration lose sodium until the normal level is regained. This net loss is due to influx being much lower and outflux much higher than normal. Of the outflux, up to 70% is initially due to renal losses and losses over the body surface are higher than normal due to the excess sodium in the blood. 4. From the results given in this and previous papers the way in which sodium balance may be achieved under normal conditions is discussed.

Changes in Tissue Composition During Acute Sodium Depletion

1956 ◽  
Vol 186 (3) ◽  
pp. 383-392 ◽  
Author(s):  
George Nichols ◽  
Nancy Nichols
Keyword(s):  
Bone Mineral ◽  
Complete Removal ◽  
Sodium Content ◽  
The Body ◽  
Sodium Deficiency ◽  
Sodium Removal ◽  
Extracellular Compartment ◽  
Body Sodium ◽  
Total Body ◽  
New Hypothesis

Migration of sodium out of body cells has been assumed to account for discrepancies observed between total losses of this ion from the body and changes in the sodium content of the extracellular compartment. To study this concept a ‘pure’ sodium deficiency was produced acutely in dogs by means of vivodialysis, resulting in the removal of approximately 23% of total body sodium. Analyses of plasma, muscle, skin, tendon, bone, heart and liver for water and electrolytes were performed before, during and after the procedure. It was found that the extracellular phase of the body contributed 70%, bone mineral 25% and body cells only 5% of the total sodium removed. The relative rates of removal of sodium from various tissues were compatible with their known vascularity and water content, with the exception of bone mineral. Highly vascular tissues, such as muscle and skin, had a rapid initial rate of sodium removal which declined with time, as sodium stores were rapidly depleted. Avascular tissues, as exemplified by tendon, showed an increasing rate of sodium removal with time, as equilibration became more complete. Removal of this fraction of total body sodium resulted in a severe, uncompensated, metabolic acidosis. Despite relatively small changes in plasma electrolytes, hypotension, vascular collapse and, in some cases, death occurred in these animals. A new hypothesis, based on current concepts of bone crystalline structure, is presented to account for the falling rate of sodium removal from bone mineral as contrasted with the increasing rate of removal from other avascular tissues.

Sodium homeostasis in conscious dogs after chronic cardiac denervation

1990 ◽  
Vol 258 (4) ◽  
pp. F805-F811 ◽  
Author(s):  
G. Kaczmarczyk ◽  
E. Schmidt
Keyword(s):  
Sodium Excretion ◽  
Plasma Renin ◽  
Dietary Sodium ◽  
Right Atrial ◽  
Sodium Balance ◽  
Cardiac Denervation ◽  
Arterial Blood ◽  
Renal Sodium Excretion ◽  
Body Sodium ◽  
Total Body

The ability to regulate renal sodium excretion after an acute reduction of total body sodium by peritoneal dialysis (PD) and subsequent dietary sodium repletion was investigated in 12 [6 intact, 6 chronically cardiac denervated (CD)] conscious, chronically instrumented dogs. For 10 days, balance experiments were performed with daily measurements of mean arterial blood pressure (MABP), right atrial pressure (RAP), and heart rate (HR). The prepared diet contained 0.5 (days 1-3 after PD) or 2.5 mmol Na.kg body wt-1.day-1 (control day and days 4-9 after PD). Control values were all similar in both groups except higher fasting plasma renin activities (PRA) were observed in the CD dogs [2.6 +/- 0.4 vs. 1.0 +/- 0.2 ng angiotensin I (ANG I).ml-1.h-1; P less than 0.05]. Days 1-4 after PD, RAP fell in both groups by 2-3 cmH2O, and renal sodium excretion decreased abruptly. PRA increased to 22.8 +/- 4.1 (intact) and 29.9 +/- 4.9 ng ANG I.ml-1.h-1 (CD dogs) (day 3 after PD). Both groups continued to retain sodium, and when it was available again, PRA decreased. After the amount of sodium lost by PD was regained, the intact dogs remained in a balanced equilibrium. In the CD dogs, PRA was still above control, and they retained sodium in excess (+ 1.9 +/- 0.1 mmol/kg body wt). We conclude that the cardiac nerves are not essential for stimulating PRA and sodium retention after an acute sodium deficit. However, the inhibition of PRA and the rapid adjustment of sodium balance during sodium repletion is impaired after cardiac denervation.

Regulation of Water and Some Ions in Gammarids (Amphipoda)

1971 ◽  
Vol 55 (2) ◽  
pp. 325-344
Author(s):  
D. W. SUTCLIFFE
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Chloride Content ◽  
Chloride Ions ◽  
Body Water ◽  
The Body ◽  
Potassium Balance ◽  
Body Sodium ◽  
External Potassium ◽  
Total Body

1. Gammarus duebeni from brackish water was acclimatized to salinities ranging from 100% sea water down to 0.25 mM/1 NaCl at 9 °C. 2. The body water content increased from 76 to 81% body wet weight. The ratio of total body sodium/chloride increased from 1.04 to 1.52. The sodium space remained constant, equivalent to about 65 % body H2O. The chloride space decreased from about 60% body H2O down to 35% body H2O. 3. Total body potassium remained almost constant and showed only a small decrease in dilute NaCl-media. Potassium balance was maintained for several days at an external potassium concentration of 0.010-0.015 mM/1. 4. The proportion of body water in the extracellular blood space was calculated from the assumption that potassium and chloride ions were distributed in a Donnan equilibrium between the blood and intracellular spaces. The blood space was slightly smaller than the chloride space. 5. The mean intracellular concentrations of sodium, potassium and chloride were calculated. Sodium fell from 120 to 75 mM/kg cell H2O, potassium fell from 125 to 75 mM/kg cell H2O and chloride fell from 55 to 12 mM/kg cell H2O. These concentrations are similar to the concentrations found in the muscles of decapods and in the tissues of other animals. 6. About 10% of the body chloride and 93-97% of the body potassium is situated in the cells. The proportion of intracellular sodium increased from 17-18% body sodium at 100% sea water to 40-50% body sodium at 0.25 mM/l NaCl. 7. G. duebeni from three freshwater populations were acclimatized to 2 % sea water, 0.5 and 0.25 mM/l NaCl. The body surface is three times more permeable to potassium than it is to sodium and chloride. Potassium balance in starved animals was achieved at 0.010-0.015 mM/l K. Fed animals had a higher body sodium and chloride content than starved animals. 8. The regulation of body water and ions in animals from the freshwater populations was essentially the same as in animals from brackish-water populations. The significance of the results is discussed in relation to the process of adaptation to fresh water.

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