Effects of Temperature on Branchial Sodium-Exchange and Extrusion Mechanisms in the Seawater-Adapted Flounder Platichthys Flesus L

1972 ◽  
Vol 56 (3) ◽  
pp. 565-585
Author(s):  
J. MAETZ ◽  
D. H. EVANS
Keyword(s):  
Sodium Content ◽  
Sodium Balance ◽  
Irreversible Damage ◽  
Simple Diffusion ◽  
Sodium Efflux ◽  
Temperature Changes ◽  
Platichthys Flesus ◽  
Sodium Load ◽  
Sodium Extrusion ◽  
Total Sodium

1. The effects of short-term and long-term temperature changes on the branchial components of sodium balance have been studied in the seawater-adapted flounder Platichthys flesus. 2. When fish adapted to 6°C are compared with fish adapted to 16°C a disturbance of sodium balance is observed; while the plasma level of sodium remains constant, an increased internal sodium space can be demonstrated isotopically. Increase of the muscle sodium content accounts for only a small part of the extra sodium content of the fish. The increased sodium load is the result of an impairment of the sodiumextrusion mechanism in the gills, and is demonstrated by the disappearance of the Na/K exchange activity of the gills. The passive sodium fluxes (by simple diffusion or exchange-diffusion) decrease only twofold. 3. Abrupt temperature changes in the 6-21°C temperature range are followed by instantaneous and reversible changes of the total sodium efflux (Q10 = 2), of the sodium leak observed after transfer into fresh water (Q10 = 1.7) and of the Na/Na exchange (Q10 = 2). The Na/K exchange, which corresponds presumably to the active sodium extrusion mechanism, shows in contrast a much greater temperature dependence (Q10 = 6). The total sodium efflux follows the Arrhenius relation between 6 and 21°C. 4. Abrupt transfer to higher temperatures (23-26 °C) produces irreversible damage to the transport system. 5. No compensatory acclimatization of the flux rates is observed during adaptation in the 6 °C environment. 6. The biological, physiological, ecological as well as biophysical implications of these findings are discussed. Particular emphasis is given to the problem of gill haemo-dynamics.

The influence of "nonmyoplasmic" sodium on the measured value of the sodium efflux from barnacle muscle

1981 ◽  
Vol 59 (12) ◽  
pp. 1219-1227 ◽  
Author(s):  
M. R. Menard ◽  
J. A. M. Hinke
Keyword(s):  
Extracellular Space ◽  
Striated Muscle ◽  
Muscle Cells ◽  
Sodium Content ◽  
Flame Photometry ◽  
Free Solution ◽  
Sodium Efflux ◽  
Barnacle Muscle ◽  
Total Sodium

In single striated muscle cells of the giant barnacle Balanus nubilus, the sodium content of the myoplasm was measured with an intracellular microelectrode, and the total sodium content of the cell was measured by flame photometry, during immersion of the cells in sodium-free solution. The sodium content of the myoplasm declined slowly but steadily from ca. 10 mmol/kg water to ca. 4 mmol/kg water during immersions lasting up to 16 h. The "nonmyoplasmic" sodium content of the cells, defined as the sodium content after subtraction of the sodium in the extracellular (sorbitol) space and in the myoplasm, declined rapidly from ca. 15 mmol/kg water to ca. 3 mmol/kg water during the first 30 min of immersion in sodium-free solution, but remained constant thereafter. The rapidly lost portion of the nonmyoplasmic sodium (ca. 12 mmol/kg water) was ascribed to the extracellular space but the location of the inexchangeable portion was not discovered. The behavior of the efflux of 22Na which was loaded into the myoplasm by microinjection was consistent with this interpretation. It was concluded that the nonmyoplasmic sodium does not have an appreciable influence on the measured value of the sodium efflux from the myoplasm of barnacle muscle cells.

Salt saving in the pregnant rat

1961 ◽  
Vol 201 (5) ◽  
pp. 765-768 ◽  
Author(s):  
I. J. Lichton
Keyword(s):  
Saline Solution ◽  
Isotonic Saline ◽  
Extracellular Fluid ◽  
Sodium Content ◽  
Sodium Balance ◽  
Sodium Retention ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Near Term ◽  
Total Sodium

Pregnant rats of two strains showed average net accumulation of approximately 83 mEq of sodium/kg of weight gain throughout gestation. Of the total sodium retention, 15, 23, and 62% occurred in each successive third of gestation. Analysis of postpartum sodium balance and of fetal sodium content at term indicated that there was no net accumulation of sodium in the tissues of the dams. Near term, rats given isotonic saline solution showed diminished ability to excrete the administered water in the urine, but showed no impairment in sodium excretion. Serum sodium concentrations were slightly decreased and serum osmolalities were significantly decreased in comparison to values for nonpregnant rats. At term the pregnant rats had greater extracellular fluid volumes than did nonpregnant controls.

The energy requirement for sodium extrusion from a frog muscle

1954 ◽  
Vol 142 (908) ◽  
pp. 383-392 ◽  
Keyword(s):  
Oxygen Consumption ◽  
Energy Production ◽  
Energy Requirement ◽  
Metabolic Inhibitors ◽  
Sodium Efflux ◽  
External Potassium ◽  
Radioactive Sodium ◽  
Sodium Extrusion ◽  
Frog Sartorius ◽  
Made In

Parallel measurements have been made of the oxygen consumption and efflux of radioactive sodium in pairs of frog sartorius muscles. Calculation of the amount of secretory work necessary for an active extrusion of sodium at the observed rate showed that it would involve the utilization of about one-tenth of the energy available from resting metabolism.This figure may reasonably be regarded as a lower limit to the efficiency of the secretory mechanism. Some of the measurements were made in a potassium-free Ringer’s solution, and others with an external potassium concentration of 10mM. In the potassium-rich medium, both the sodium efflux and the oxygen consumption were increased, the proportion of the energy production required for sodium extrusion remaining roughly constant. The action of dinitrophenol and other metabolic inhibitors on the sodium efflux in sartorius muscles was examined, but there were no very obvious effects.

Basal Activity of the Natriuretic Factor Extracted from the Rat Kidney as a Function of the Diet and its Role in the Regulation of the Acute Sodium Balance

1980 ◽  
Vol 58 (5) ◽  
pp. 385-391 ◽  
Author(s):  
F. Louis ◽  
H. Favre
Keyword(s):  
Sodium Intake ◽  
Rat Kidney ◽  
Extracellular Volume ◽  
Gel Filtration ◽  
Kidney Tissue ◽  
Weight Fraction ◽  
Sodium Content ◽  
Sodium Balance ◽  
Low Molecular Weight ◽  
Extracellular Volume Expansion

1. The effect of the sodium content of the diet on the natriuretic activity of an extract from the kidneys was studied in non-expanded and volume-expanded rats. 2. The kidney tissue was homogenized and the supernatant fractionated by gel filtration on Sephadex G-25. A single low-molecular-weight fraction eluted after the salt possessed the natriuretic activity and was tested on a rat bioassay. 3. The natriuretic activity of the fraction obtained from the kidneys of non-expanded rats was related to the sodium intake. 4. After an acute extracellular volume expansion, the natriuretic activity obtained from the fraction extracted from the kidneys was much greater than before expansion and was related to the dietary intake of sodium.

scholarly journals Sodium intake and dietary sources of sodium in undergraduate students from Novi Sad, Serbia

2016 ◽  
Vol 73 (7) ◽  
pp. 651-656 ◽  
Author(s):  
Jelena Jovicic-Bata ◽  
Maja Grujicic ◽  
Slavica Radjen ◽  
Budimka Novakovic
Keyword(s):  
Undergraduate Students ◽  
Sodium Intake ◽  
Sodium Content ◽  
Bakery Products ◽  
Food Groups ◽  
High Sodium ◽  
Dietary Recall ◽  
Novi Sad ◽  
The University ◽  
Total Sodium

Background/Aim. Data on sodium intake and sources of sodium in the diet in Serbia are limited. The aim of this study was to estimate the sodium intake and identify the sources of sodium in the diet of undergraduate students attending the University of Novi Sad. Methods. Students completed a questionnaire to gather data on their gender, age and university faculty attended, and then a 24 h dietary recall. The sodium intake of the students was calculated using the dietary recall data and data on the sodium content of foods. The contribution of different food groups as well as of specific foodstuffs to the total sodium intake was calculated. Results. The mean estimated sodium intake of the students was 3,938.5 ? 1,708.1 mg/day. The sodium intake of 89.1% of the surveyed students exceeded the guideline for sodium intake, the majority of the sodium coming from processed foods (78.9% of the total sodium intake). The food groups that contributed the most to the total sodium intake of the students were meat and meat products (21.7%) and cereals and cereal-based products (18.6%). Bread and other bakery products were responsible for 13.1% of the total sodium intake. Conclusion. High sodium intake in students of the University of Novi Sad puts them at high risk of developing high blood pressure. The food industry should work towards reformulating products with high sodium content, especially bread and other bakery products. Efforts should be taken to reduce sodium intake among undergraduate students in Novi Sad.

Comparative Effects of Temperature on the Sodium and Water Permeabilities of the Gills of a Stenohaline Freshwater Fish (Carassius Auratus) and a Stenohaline Marine Fish (Serranus Scriba, Serranus Cabrilla)

1972 ◽  
Vol 57 (2) ◽  
pp. 359-366 ◽  
Author(s):  
J. ISAIA
Keyword(s):  
Freshwater Fish ◽  
Marine Fish ◽  
Osmotic Gradient ◽  
Water Fluxes ◽  
Simple Diffusion ◽  
Temperature Changes ◽  
Diffusional Permeability ◽  
Effects Of Temperature ◽  
Sea Perch ◽  
Branchial Membrane

1. Comparative effects of temperature on the permeability of the gill to water and to sodium were studied in the marine sea perch Serranus and the freshwater goldfish Carassius. 2. The acclimation Q10 for the water fluxes is higher in the freshwater fish than in the marine fish. 3. In the goldfish the osmotic permeability (Pos) is greater than the diffusional permeability (Pdlf) at all acclimation temperatures, suggesting the presence of ‘waterfilled channels’ in the branchial membrane. In the sea perch, on the other hand, Pos/Pdlf is approximately 1, indicating that water movements probably occur by simple diffusion. 4. The permeabilities to water and to sodium are similar in the sea perch but very different in the goldfish. Considering these results together with those from a similar study on an elasmobranch, it would seem that the more perfect the semipermeability of the gill membrane and the weaker the transepithelial osmotic gradient, the greater is the branchial porosity. 5. Assuming that temperature changes do not cause modification of the branchial surface or relative permeabilities to water and to sodium the independence of the temperature-coefficient variations for water and for sodium indicates a certain dissociation between the movements of salt and of water, in the sea perch. In the goldfish, assuming a constant branchial surface and in view of the fact that Pos > Pdif the high temperature coefficients for the water fluxes suggest that the water in the ‘water-filled channels’ is in a highly organized state.

The Effect of External Potassium Ions on the Electrical Potential Measured Across the Gills of the Teleost, Dormitator Maculatus

1974 ◽  
Vol 61 (2) ◽  
pp. 277-283
Author(s):  
DAVID H. EVANS ◽  
JEFFREY C. CARRIER ◽  
MARGARET B. BOGAN
Keyword(s):  
Sea Water ◽  
Electrical Potential ◽  
Potassium Ions ◽  
Sodium Efflux ◽  
Electrical Potentials ◽  
External Potassium ◽  
Potassium Influx ◽  
Sodium Extrusion ◽  
Sufficient Magnitude ◽  
Stimulation Of

1. A technique has been developed for the measurement of electrical potentials (TGP's) across the gills of free-swimming, Dormitator maculatus. 2. Transfer of fish to various KCl solutions is correlated with changes in the TGP, which are not of sufficient magnitude to account for the known potassium stimulation of sodium efflux from this species. 3. Transfer to potassium-free sea water results in little or no change in TGP while previous results have shown that such a transfer is correlated with a 22% reduction of sodium efflux. 4. Transfer to fresh water results in a reduction of TGP from +17 mV (inside positive) to -36 mV which is sufficient to account for the instantaneous reduction in sodium efflux previously shown for this species. 5. It is concluded that while changes in TGP can account for the ‘Na-free effect’ in D. maculatus they cannot account for the potassium effects on sodium extrusion. This supports the previous conclusion that sodium efflux and potassium influx are chemically linked in this species.

Sodium exchange and distribution in the arterial wall

1965 ◽  
Vol 209 (5) ◽  
pp. 955-960 ◽  
Author(s):  
P. Garrahan ◽  
M. F. Villamil ◽  
J. A. Zadunaisky
Keyword(s):  
Temperature Coefficient ◽  
Phase 1 ◽  
Compartmental Analysis ◽  
Sodium Concentration ◽  
Sodium Content ◽  
Phase 2 ◽  
Fresh Tissue ◽  
Intracellular Sodium Concentration ◽  
Diffusion Curve ◽  
Total Sodium

Pieces of dog carotid artery were studied with respect to water and sodium content. Total sodium content averaged 113 ± 1.2 mm/kg fresh tissue; total water 73.6 ± 0.3% and inulin space 36.2 ± 0.5% of tissue wet wt. A total of 94.8 ± 1.3% of sodium exchanged within 6–12 min with Na22, and 97.4 ± 0.7% of the stable sodium was extracted in sodium-free solution (choline replacement). The curve of efflux of Na22 at 37 C could be decomposed into three simple exponentials with half-times of 42.5 ± 2.3 sec ( phase 1), 5.0 ± 0.3 min ( phase 2), and 71.0 ± 7.3 min ( phase 3). Exchange of sodium of phase 1 (extracellular) fitted well with a theoretical diffusion curve, showed low temperature coefficient and no potassium dependency, and was not influenced by ouabain. Exchange of sodium of phase 2 (cellular) showed high temperature coefficient and potassium dependency and was sensitive to ouabain. Calculations based on the compartmental analysis indicate a too-great intracellular sodium concentration. Binding of sodium to polyanions in the extracellular space is suggested as a possible explanation of the results.

Hormonal and Neural Mechanisms of Sodium Appetite

Physiology ◽  
1986 ◽  
Vol 1 (2) ◽  
pp. 51-54 ◽  
Author(s):  
MJ Fregly ◽  
NE Rowland
Keyword(s):  
Sodium Content ◽  
Neural Mechanisms ◽  
Sodium Balance ◽  
Salt Appetite ◽  
Sodium Appetite ◽  
Complex Mechanisms

A strong appetite for salt seems to be a normal link in the complex mechanisms that serve to maintain a normal sodium content of the organism. Experiments with rats have helped to unravel many aspects of the endocrine mechanisms that are involved in regulating sodium balance and salt appetite, but more work is needed to understand the mechanisms that induce salt appetite in different species.

Role of renal nerves in renal sodium retention of nephrotic syndrome

1989 ◽  
Vol 256 (5) ◽  
pp. F823-F829 ◽  
Author(s):  
P. J. Herman ◽  
L. L. Sawin ◽  
G. F. DiBona
Keyword(s):  
Nephrotic Syndrome ◽  
Renal Denervation ◽  
Sodium Content ◽  
Vehicle Control ◽  
Dietary Sodium ◽  
Sodium Balance ◽  
Renal Nerves ◽  
Sodium Retention ◽  
Edema Formation

To define the role of the renal nerves in the renal sodium retention of the nephrotic syndrome, experiments were conducted in rats given adriamycin to produce nephrotic syndrome. All rats developed proteinuria and hypoalbuminemia and exhibited edema formation. Adriamycin-injected nephrotic rats were subjected to bilateral renal denervation (ADRIADNX) or sham renal denervation (ADRIASHAM). Rats injected with adriamycin vehicle were subjected to bilateral renal denervation (DNX) or sham renal denervation (SHAM). Metabolic balance studies were carried out in all rats beginning on the 8th day after bilateral or sham renal denervation. Dietary sodium content was 210 meq/kg Na on days 8-12 and days 24-26 and was 10 meq/kg Na on days 13-23. Nephrotic rats demonstrated significantly greater overall (19 days) cumulative sodium balance than vehicle control rats, ADRIASHAM 8.47 +/- 0.81 vs. SHAM 5.74 +/- 0.34 meq Na, P less than 0.01. Bilateral renal denervation did not significantly affect overall cumulative sodium balance in the vehicle control rats, DNX 6.15 +/- 0.71 vs. SHAM 5.74 +/- 0.34 meq Na. However, bilateral renal denervation significantly decreased overall cumulative sodium balance in the nephrotic rats, ADRIADNX 6.59 +/- 0.56 vs. ADRIASHAM 8.47 +/- 0.81 meq Na, P less than 0.01. Results indicated that the increased renal sodium retention characteristic of nephrotic syndrome is dependent, in large part, on increased efferent renal sympathetic nerve activity.

Sign in / Sign up

Export Citation Format

Share Document