Improving Renoprotective Therapy by Targeting the Body Sodium Balance

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.

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Salt and water balance and renin activity in renal hypertension of rats

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1975.228.6.1847 ◽

1975 ◽

Vol 228 (6) ◽

pp. 1847-1855 ◽

Cited By ~ 104

Author(s):

J Mohring ◽

B Mohring ◽

H-J Naumann ◽

A Philippi ◽

E Homsy ◽

...

Keyword(s):

Water Balance ◽

Renal Artery ◽

Renal Hypertension ◽

The Body ◽

Renin Activity ◽

Sodium Balance ◽

Sprague Dawley ◽

Contralateral Kidney ◽

Salt And Water Balance ◽

Renal Artery Constriction

In male Sprague-Dawley rats, renal artery constriction in the presence of an inact contralateral kidney induced sodium retention (for 2-3 wk), moderate potassium loss,elevation of blood volume (BV), and an increase in water turnover. It is suggestedthat renal artery constriction activates the renin-angiotensin-aldosterone system, resulting in disordered regulation of salt and water balance and in blood pressure (BP) elevation. Subsequently, sodium balance was reestablished in one group of hypertensive rats. The previously retained sodium was kept in the body, and BV and reninactivity remained elevated. In a second group of animals, a malignant course of hypertension developed: BP surpassed a critical level of about 180 mmHg; sodium, potassium, and water were lost; BV declined; renin activity was further stimulated; and in the contralateral kidney malignant nephrosclerosis occurred. It is assumed that pressure diuresis and natriuresis induce a vicious circle: the increasing renin activity may maintain or further increase BP level, therby inducing further salt and water loss, etc.; high BP levels and high renin activities induce vascular damage and deterioration of renal function.

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Sodium Balance in Eriocheir Sinensis (M. EDW.). The Adaptation of the Crustacea to Fresh Water

Journal of Experimental Biology ◽

10.1242/jeb.38.1.153 ◽

1961 ◽

Vol 38 (1) ◽

pp. 153-162

Author(s):

J. SHAW

Keyword(s):

Fresh Water ◽

Body Surface ◽

Eriocheir Sinensis ◽

Vital Role ◽

The Body ◽

Sodium Balance ◽

Progressive Reduction ◽

Uptake Mechanism ◽

Active Uptake ◽

Main Factors

1. In Eriocheir sinensis active uptake of sodium plays a vital role in the maintenance of sodium balance. At external concentrations down to about 6 mM./l. the active uptake mechanism is fully saturated and the uptake rate just balances the rate of loss, which occurs primarily through the body surface. At lower external concentrations balance may be achieved, at least in part, by the activation of the uptake mechanism. 2. A hypothesis is put forward to account for the mechanism of adaptation of the Crustacea to fresh water. Two main factors are involved: (a) a progressive reduction in the permeability of the body surface to salts and, (b) the acquisition of an active uptake mechanism with a high affinity for the ions which it transports. 3. This hypothesis is discussed in relation to previous theories on the adaptation of the Crustacea to fresh water.

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Sodium, Potassium and Nitrogen Balances in Chronic Nephrectomized Dogs

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1956.185.1.175 ◽

1956 ◽

Vol 185 (1) ◽

pp. 175-178

Author(s):

C. Riley Houck

Keyword(s):

Peritoneal Dialysis ◽

Plasma Protein ◽

Nitrogen Balance ◽

Potassium Concentration ◽

The Body ◽

Sodium Balance ◽

Sodium Potassium ◽

Peritoneal Dialysate ◽

Low Salt

Twelve bilaterally nephrectomized dogs on a low-salt, 54 cal/kg/day diet were maintained for periods up to 3 weeks by intermittent peritoneal dialysis. This procedure maintained the animals in normal sodium balance but provided both a negative potassium and nitrogen balance. The over-all loss of potassium occurred even though the dialysate potassium concentration was varied from 2.8–3.7 mEq/l. It is believed that the negative K and N balances are brought about by loss of plasma protein and some erythrocytes into the peritoneal dialysate. The data indicate that K and N are not lost from the body in the same ratio that they occur in tissues. Renoprival hypertension developes despite failure of the body to retain sodium and despite loss of both potassium and nitrogen from the body.

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Oxytocinergic and serotonergic systems involvement in sodium intake regulation: satiety or hypertonicity markers?

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00078.2007 ◽

2007 ◽

Vol 293 (3) ◽

pp. R1027-R1036 ◽

Cited By ~ 17

Author(s):

Andrea Godino ◽

Laurival Antonio De Luca ◽

José Antunes-Rodrigues ◽

Laura Vivas

Keyword(s):

Plasma Levels ◽

Supraoptic Nucleus ◽

Sodium Intake ◽

The Body ◽

Nacl Solution ◽

Sodium Appetite ◽

Body Sodium ◽

Intake Regulation ◽

Sodium Consumption ◽

Sodium Solution

Previous studies demonstrated the inhibitory participation of serotonergic (5-HT) and oxytocinergic (OT) neurons on sodium appetite induced by peritoneal dialysis (PD) in rats. The activity of 5-HT neurons increases after PD-induced 2% NaCl intake and decreases after sodium depletion; however, the activity of the OT neurons appears only after PD-induced 2% NaCl intake. To discriminate whether the differential activations of the 5-HT and OT neurons in this model are a consequence of the sodium satiation process or are the result of stimulation caused by the entry to the body of a hypertonic sodium solution during sodium access, we analyzed the number of Fos-5-HT- and Fos-OT-immunoreactive neurons in the dorsal raphe nucleus and the paraventricular nucleus of the hypothalamus-supraoptic nucleus, respectively, after isotonic vs. hypertonic NaCl intake induced by PD. We also studied the OT plasma levels after PD-induced isotonic or hypertonic NaCl intake. Sodium intake induced by PD significantly increased the number of Fos-5-HT cells, independently of the concentration of NaCl consumed. In contrast, the number of Fos-OT neurons increased after hypertonic NaCl intake, in both depleted and nondepleted animals. The OT plasma levels significantly increased only in the PD-induced 2% NaCl intake group in relation to others, showing a synergic effect of both factors. In summary, 5-HT neurons were activated after body sodium status was reestablished, suggesting that this system is activated under conditions of satiety. In terms of the OT system, both OT neural activity and OT plasma levels were increased by the entry of hypertonic NaCl solution during sodium consumption, suggesting that this system is involved in the processing of hyperosmotic signals.

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Regulation of Water and Some Ions in Gammarids (Amphipoda)

Journal of Experimental Biology ◽

10.1242/jeb.55.2.357 ◽

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.

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Control of aldosterone secretion by change of body potassium in normal man

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1964.207.1.104 ◽

1964 ◽

Vol 207 (1) ◽

pp. 104-108 ◽

Cited By ~ 45

Author(s):

Donald S. Gann ◽

Catherine S. Delea ◽

John R. Gill ◽

J. Picton Thomas ◽

Frederic C. Bartter

Keyword(s):

Arterial Pressure ◽

Plasma Volume ◽

Normal Subjects ◽

Dietary Sodium ◽

Sodium Balance ◽

Potassium Depletion ◽

Intravascular Volume ◽

Aldosterone Secretion ◽

Body Sodium ◽

Normal Man

Seven normal subjects were subjected to depletion and repletion of body potassium on balance regimen. Aldosterone excretion, plasma volume, and arterial pressure were measured. Potassium depletion decreased and potassium repletion consistently increased aldosterone excretion. Changes in sodium balance were prevented by restricting dietary sodium or replacing lost sodium. The effects on aldosterone excretion were thus shown to be independent of reciprocal changes in sodium balance of intravascular volume or of arterial pressure. The results suggest that changes in body potassium influence aldosterone secretion by mechanisms independent of those responsive to changes in body sodium or fluid volume.

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

Journal of Experimental Biology ◽

10.1242/jeb.61.3.719 ◽

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.

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Regulation of Water and Some Ions in Gammarids (Amphipoda)

Journal of Experimental Biology ◽

10.1242/jeb.55.2.345 ◽

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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