Net Sodium Loss Research Articles

Potential nutrition contributions to exercise-associated muscle cramping in four recreational half-marathoners: A case series

Objectives: Nutrition-related practices and outcomes vary dramatically between athletes, and traditional beliefs regarding the role of electrolytes and hydration in exercise-associated muscle cramping (EAMC) may be hindering meaningful prevention strategies. The aim of this study was to characterize the role of carbohydrate (CHO), energy, and exertion level, in conjunction with electrolyte and hydration status to assess the role of these possible predictors of EAMC.
 Methods: A case study series approach was used to capture pre-race and on-course food and beverage intake, pre and post-race body weight, relative perceived exertion (RPE), and history of EAMC for four recreational runners prior to and during a half-marathon race.
 Results: CHO intake, energy intake, and hydration status varied among the runners with one occurrence of EAMC. Reported pre-race CHO intake for all but one runner fell below 5 g/kg/day. Weight loss during the race was between 1.23-3.03%. Two of the four runners reported a prior history of EAMC, one of which experienced EAMC during the race. The two runners with a prior history of EAMC, also reported the lowest 3-day energy and CHO intakes. The one runner who encountered an EAMC did not experience the greatest net race sodium loss. However, this runner did have the greatest race weight loss, the greatest race sweat loss, the longest duration of activity, the lowest RPE, and suboptimal energy and CHO intakes.
 Conclusions: The observed case of EAMC does not appear to be entirely inconsistent with the traditional dehydration/ electrolyte loss theory. However, the in-depth characterization of each runner illustrates the complex interaction of potential predictors and also generates questions regarding the potential contribution of suboptimal energy and CHO intakes.

Reverse translation: effects of acclimation temperature and acute temperature challenges on oxygen consumption, diffusive water flux, net sodium loss rates, Q10 values and mass scaling coefficients in the rainbow trout (Oncorhynchus mykiss).

Our understanding is limited on how fish adjust the effective permeability of their branchial epithelium to ions and water while altering O2 uptake rate (MO2) with acute and chronic changes in temperature. We investigated the effects of acclimation temperature (8°C, 13°C and 18°C) and acute temperature challenges [acute rise (acclimated at 8°C, measured at 13°C and 18°C), acute drop (acclimated at 18°C, measured at 8°C and 13°C) and intermediate (acclimated at 13°C, measured at 8°C and 18°C)] on routine MO2, diffusive water flux, and net sodium loss rates in 24-h fasted rainbow trout (Oncorhynchus mykiss). In the temperature challenge tests, measurements were made during the first hour. In acclimated trout at all temperatures, allometric mass scaling coefficients were much higher for diffusive water flux than for MO2. Furthermore, the diffusive water flux rate was more responsive (overall Q10 = 2.75) compared to MO2 (Q10 = 1.80) over the 8-18°C range, and for both, Q10 values were greater at 8-13°C than at 13-18°C. The net Na+ flux rates were highly sensitive to acclimation temperature with an overall Q10 of 3.01 for 8-18°C. In contrast, very different patterns occurred in trout subjected to acute temperature challenges. The net Na+ flux rate was temperature-insensitive with a Q10 around 1.0. Both MO2 and diffusive water flux rates exhibited lower Q10 values than for the acclimated rates in response to either acute increases or decreases in temperature. These results fit Pattern 5 of Precht (undercompensation, reverse effect) and more precisely Pattern IIB of Prosser (reverse translation). These inverse compensatory patterns suggest that trout do not alter their rates very much when undergoing acute thermal challenges (diurnal fluctuations, migration through the thermocline). The greater changes seen with acclimation may be adaptive to long-term seasonal changes in temperature. We discuss the roles of aquaporins, spontaneous activity, and recent feeding in these responses.

The osmorespiratory compromise in rainbow trout (Oncorhynchus mykiss): The effects of fish size, hypoxia, temperature and strenuous exercise on gill diffusive water fluxes and sodium net loss rates

In the context of the osmorespiratory compromise, hypoxia and temperature have been little studied relative to exercise, and diffusive water flux rates (as assessed by 3H2O efflux) have received almost no attention. We investigated the effects of fish size, hypoxia, exercise and acute temperature increase on diffusive water flux rates and net sodium loss rates in juvenile rainbow trout. Trout weighing 13–50 g were used to determine the effects of fish size under normoxia. Thereafter 25–50 g trout were selected to assess the effects of different hypoxia levels (3.15, 5.25 and 8.40 KPa), time course of hypoxia (1 h 8.40 KPa, 3 h 8.40 KPa, 1 h 8.40 KPa +1 h normoxic recovery, and 1 h 8.40 KPa + 3 h normoxic recovery), strenuous exercise (5 min) and acute temperature challenge (transfer from 8 °C to 13 °C or to 18 °C). Small fish (13 g) had higher diffusive water flux rates than larger fish, turning over >100% of their fractional body water pool per hour against 34% per hour for 50 g fish. Hypoxic exposure exerted a biphasic effect, increasing the diffusive water flux rate at 8.40 KPa and 5.25 KPa, while returning it to control levels at 3.15 KPa. All the levels of hypoxia increased net Na+ loss. One hour hypoxia (8.40 KPa) increased diffusive water flux rate while prolonged 3 h hypoxia (8.40 KPa), and short or prolonged normoxic recovery returned diffusive water flux rates to control levels. All the treatments over the time course of hypoxia and normoxic recovery increased net Na+ loss rates. Strenuous exercise increased both the diffusive water flux and net Na+ loss rates. Acute temperature rise increased diffusive water flux rates, with Q10 values of 4.03 for 8 to 13 °C and 2.16 for 8 to 18 °C, but the net Na+ loss rate did not change. There was no significant correlation between diffusive water flux rate and net Na+ loss rates at different hypoxia levels, over the course of hypoxia and normoxic recovery, or during acute temperature stress. In contrast, we observed a significant correlation between diffusive water flux and net Na+ loss rates following exercise. Overall, diffusive water flux and sodium loss were regulated differently during acute temperature challenge and hypoxia, while following exercise the two parameters were regulated in a similar fashion.

Experimental evaluation of diuretic effect of Usheera Moola - Vetiveria Zizanioides (Linn.) Nash

By literary survey Usheera is mentioned from Vedakala. Some Nighantus and some Ayurvedic modern books mention that, it has Mootravirechaniya action used in Mootrakricchra. This drug is easily available and grows all over India. Hence roots of Vetiveria zizanioides (Linn) Nash i.e. Usheera was selected for this study. Most of Ayurvedic drugs or formulations are known for their safety and efficacy. Hence literary research is done to specify a medicine that can act as a diuretic. Lots of drugs are mentioned as Mootravirechaniya (diuretic) in Ayurvedic classics. Here Mootravirechaniya is also called as Bastishodhana and Mootrala. They are having Sheeta Veerya or Ushna Veerya, Madhura, Amla, Lavana Rasas, Drava and Upakledi properties. The selected drug Usheera is having Sheeta and Madhura properties. Diuretics are the drugs which cause a net loss of sodium and water in urine. These are widely prescribed drugs. They are used whenever there is need to eliminate excess of water and ion accumulated in tissues.

Hyponatremia

Hyponatremia

Drugs outperform ultrafiltration in acute cardiorenal syndrome

Around 25–33% of patients with acute decompensated heart failure develop worsening kidney function, a condition referred to as acute cardiorenal syndrome (type 1). Diuretics are commonly used to treat persistent congestion in these patients, but these drugs might worsen kidney function. An alternative therapeutic approach is venovenous ultrafiltration, which can improve control over the rate and volume of fluid removal, increase net loss of sodium, and reduce neurohormonal activation. To address the lack of data on the use of ultrafiltration in patients with acute decompensated heart failure, investigators designed CARRESS-HF, the results of which were presented at the AHA 2012 Scientific Sessions and published in the New England Journal of Medicine.

Drugs outperform ultrafiltration in acute cardiorenal syndrome

Around 25–33% of patients with acute decompensated heart failure develop worsening kidney function, a condition referred to as acute cardiorenal syndrome (type 1). Diuretics are commonly used to treat persistent congestion in these patients, but these drugs might worsen kidney function. An alternative therapeutic approach is venovenous ultrafiltration, which can improve control over the rate and volume of fluid removal, increase net loss of sodium, and reduce neurohormonal activation. To address the lack of data on the use of ultrafiltration in patients with acute decompensated heart failure, investigators designed CARRESS-HF, the results of which were presented at the AHA 2012 Scientific Sessions and published in the New England Journal of Medicine.

The effect of starving and feeding on copper toxicity and uptake in Cu acclimated and non-acclimated carp

Common carp ( Cyprinus carpio) were fed two different food rations: 0.5% body weight (low ration, LR) and 5% body weight (high ration, HR) and were either acclimated to sublethal copper (1 μM) for 28 days in softened Antwerp city tap water or not acclimated. Fish were exposed for 10 days to high Cu levels using four different concentrations (3.5, 6, 10, and 15 μM) before and after the Cu acclimation. Fish tolerance against Cu exposure was evaluated, and gill, liver, and carcass Cu and sodium levels were measured in dead and surviving fish. HR fish were twice as sensitive as LR fish in both tests. The 96 h median lethal concentration (LC50) values for the non-acclimated LR and HR fish were 8.46 ± 2.79 and 4.34 ± 0.82 μM, respectively. The fish became more resistant to low Cu concentrations after Cu acclimation and the LC50 values were slightly increased, reaching 9.20 ± 1.56 μM and 5.01 ± 1.93 in LR and HR fish accordingly. Cu concentrations in the gills, liver, and carcass were significantly elevated in response to the short-term Cu exposure, and were significantly higher in LR fish than in HR fish. High Cu levels caused a net loss of sodium resulting in a severe ion regulatory disturbance. The rate of sodium loss increased linearly with increasing exposure concentrations. Cu acclimation resulted in reduced sodium loss and increased the resistance and tolerance to Cu toxicity.

The Role Of Diuretics In The Intensive Care Unit: A Review

Diuretics are drugs which cause a net loss of sodium and water from the body by net action on the kidney. Their primary effect is to decrease the reabsorption of sodium and chloride from the filtrate, increased water loss being secondary to the increased excretion of salt. There are various classes of diuretics which differ considerably in chemical derivation, efficacy, sites of action, and mechanism of action; namely, their pharmacology and pharmacodynamics. Effective use of diuretics requires knowledge of the pharmacology of each diuretic agent coupled with an understanding of the pathophysiology of the patient's disease. Diuretics have various uses in clinical conditions including oedematous disorders and hypertension, treatment of hypercalcaemia with loop diuretics, treatment of diabetes insipidus or hypercalciuria with thiazide diuretics, treatment of glaucoma with carbonic anhydrase inhibitors, and treatment of cerebral oedema with osmotic agents. The use of diuretics in the acute care setting is an area of significant clinical and laboratory research. Diuretics represent one of the most commonly used agents in the intensive care unit and fluid balance occupies a significant amount of attention by the intensivist and the anaesthetist. The author's aim was to systematically review the literature regarding the use of diuretics in critically ill patients on the Intensive Care Unit. We searched MEDLINE (1966-2004), EMBASE (1974-2004) and the Cochrane Controlled Trials Register (CCTR) to identify randomised controlled trials, in order to review the risks and benefits of diuretics in four different groups of patients. These included subjects with acute renal failure, congestive heart failure, severe head injury and also preterm infants with respiratory distress syndrome.

Biogenesis and early life on Earth and Europa: favored by an alkaline ocean?

Recent discoveries about Europa--the probable existence of a sizeable ocean below its ice crust; the detection of hydrated sodium carbonates, among other salts; and the calculation of a net loss of sodium from the subsurface--suggest the existence of an alkaline ocean. Alkaline oceans (nicknamed "soda oceans" in analogy to terrestrial soda lakes) have been hypothesized also for early Earth and Mars on the basis of mass balance considerations involving total amounts of acids available for weathering and the composition of the early crust. Such an environment could be favorable to biogenesis since it may have provided for very low Ca2+ concentrations mandatory for the biochemical function of proteins. A rapid loss of CO2 from Europa's atmosphere may have led to freezing oceans. Alkaline brine bubbles embedded in ice in freezing and impact-thawing oceans could have provided a suitable environment for protocell formation and the large number of trials needed for biogenesis. Understanding these processes could be central to assessing the probability of life on Europa.

Language guiding therapy: the case of dehydration versus volume depletion.

Indiscriminate use of the terms dehydration and volume depletion, so carefully crafted by our predecessors, risks confusion and therapeutic errors. These two conditions should be distinguished at the bedside and in how we speak to one another. Dehydration largely refers to intracellular water deficits stemming from hypertonicity and a disturbance in water metabolism. The diagnosis of dehydration cannot be established without laboratory analysis of p[Na +] or calculation of serum tonicity. In contrast, volume depletion describes the net loss of total body sodium and a reduction in intravascular volume and is best termed extracellular fluid volume depletion. The diagnosis of this condition relies principally on history, careful physical examination, and adjunctive data from laboratory studies. The pathophysiology of both dehydration and extracellular fluid volume depletion must be understood if these conditions are to be recognized and appropriately treated when they occur separately or together. There is no inclusive therapy for all situations. For example, indiscriminate treatment with 0.45% saline cannot be recommended when these conditions coexist because extracellular fluid volume depletion is often treated rapidly with 0.9% saline and dehydration is often treated more slowly with 5% dextrose.

The body ion loss biomarker. 1. Interactions between trace metals and low pH in reconstituted coal mine‐polluted water

AbstractNet body ion loss of brook charr (Salvelinus fontinalis) was evaluated as a biomarker of the potential toxicity of coal mine‐polluted water. Fish were exposed in reconstituted coal mine‐polluted water prepared in a continuously flowing system with a mixture of 16 water chemistry variables adjusted to match stream concentrations measured in moderately and severely mine‐impacted streams. Changes in net body cation (Na+, K+, and Ca2+) loss rates from the fish were determined. Metal/pH interactions were tested by exposing fish to (1) a mixture of all six potentially toxic metals (Al, Fe, Zn, Mn, Ni, and Cd or Pb), (2) individual metals, (3) no metals (low pH effect), or (4) time control. At severe levels (pH ≈ 3.34) all metal treatments caused a net whole‐body sodium loss rate similar to that observed for pH alone. Body potassium rates were essentially unchanged from that of the control; a significant calcium influx observed under control conditions was eliminated by most acid and metal exposures. At less severe pollution levels (pH ≈ 3.95) some metals (Ni2+, Mn2+, and Zn2+) blocked the net loss of body sodium induced by acidity. We conclude that net body sodium loss rate is a sensitive, reproducible, and acute indicator of acid and trace metal pollution and may be a useful biomarker for determining the presence and degree of impact of coal mine‐polluted water on fish.

THE BODY ION LOSS BIOMARKER. 1. INTERACTIONS BETWEEN TRACE METALS AND LOW pH IN RECONSTITUTED COAL MINE-POLLUTED WATER

Net body ion loss of brook charr (Salvelinus fontinalis) was evaluated as a biomarker of the potential toxicity of coal mine-polluted water. Fish were exposed in reconstituted coal mine-polluted water prepared in a continuously flowing system with a mixture of 16 water chemistry variables adjusted to match stream concentrations measured in moderately and severely mine-impacted streams. Changes in net body cation (Na+, K+, and Ca2+) loss rates from the fish were determined. Metal/pH interactions were tested by exposing fish to (1) a mixture of all six potentially toxic metals (Al, Fe, Zn, Mn, Ni, and Cd or Pb), (2) individual metals, (3) no metals (low pH effect), or (4) time control. At severe levels (pH ≈ 3.34) all metal treatments caused a net whole-body sodium loss rate similar to that observed for pH alone. Body potassium rates were essentially unchanged from that of the control; a significant calcium influx observed under control conditions was eliminated by most acid and metal exposures. At less severe pollution levels (pH ≈ 3.95) some metals (Ni2+, Mn2+, and Zn2+) blocked the net loss of body sodium induced by acidity. We conclude that net body sodium loss rate is a sensitive, reproducible, and acute indicator of acid and trace metal pollution and may be a useful biomarker for determining the presence and degree of impact of coal mine-polluted water on fish.

Prolonged stimulation of intrarenal V1 vasopressin receptors results in sustained hypertension.

In an earlier study, we reported that chronic intravenous administration of the V1 agonist [Phe2,Ile3,Orn8]vasopressin (V1AG) results in sustained hypertension. The present study was designed to determine whether V1-induced hypertension may be related specifically to intrarenal actions of this peptide. Chronic infusion of the V1 agonist into the medullary interstitial space of a single remaining kidney of normal, conscious Sprague-Dawley rats at the rate of 2 ng.kg-1.min-1 for 14 days resulted in a sustained rise of 18 mmHg of mean arterial pressure (MAP). After withdrawal of V1AG, MAP returned to the baseline level. During the first day of V1AG infusion, there was a net loss of body sodium and no evidence of fluid retention throughout the period of hypertension. Plasma osmolality, sodium and potassium concentration, and water intake and body weight were not significantly affected by medullary interstitial infusion of V1AG. Renal medullary interstitial infusion of an equimolar amount of arginine vasopressin (AVP) did not affect MAP. Chronic medullary interstitial infusion of the selective V1 antagonist d(CH2)5[Tyr(Me)2,Ala-NH(2)9]AVP in equimolar amounts (2.5 ng.kg-1.min-1) prevented the MAP increase elicited by intravenous V1AG. However, intravenous administration of the V1 antagonist at the same rate together with V1AG (n = 7) failed to prevent hypertension. The results indicate that hypertension can be elicited by chronic stimulation of renal medullary V1 vasopressin receptors. They also suggest that some V2 agonistic properties of AVP may restrict the hypertensive action of this hormone. The mechanism for the rise of arterial pressure remains to be determined.

The Contribution of Hemofiltration among the Treatment Modalities of Chronic Uremia

To assess the role of hemofiltration (HF) among different treatment modalities, we reviewed our clinical material from 37 patients that consecutively underwent the treatment from 1981 on. A number of 12 patients on HF for at least 1 year deliberately switched to hemodialysis (HD) or hemodiafiltration (HDF) were studied retrospectively. Biochemical and nutritional parameters, cardiovascular aspects and morbidity data were collected during one year before and after the treatment change. A sodium balance study was performed in 9 patients during HF as well. No significant differences in plasma urea, creatinine, phosphate, body weight, serum albumin, transferrin, hemoglobin and PCR were found. BUN tended to be lower during HD-HDF because of the more efficient removal of urea with these treatments. Indeed, the Kt/V index was 0.91 during HF and it was 1.15 with HD-HDF. There were no differences in hypotensive episodes and morbidity. Sodium loss was strictly related to body fluid removal during HF session with a net sodium loss (NSL) of 128 mEq per liter of fluid removal (FR) (NSL = 6.44 + 122 FR; r:0.83; p < 0.01). Adapting sodium concentration of substitution fluid to patients weight gain, cardiovascular stability improved in those subjects more prone to collapse. With equivalence in PCR during the 2 periods, although Kt/V was 20% lower during HF, it seems reasonable to assume that the lower urea clearance might be compensated by the more efficient removal of higher molecular weight substances and/or by the improved biocompatibility of HF.

A volume-independent component to postdiuretic sodium retention in humans.

Net sodium (Na) loss during diuretic administration is limited by postdiuretic renal salt retention. This could be a homeostatic response to extracellular fluid volume (ECV) depletion. However, rats infused with loop diuretics develop structural and functional adaptations in the distal nephron that enhance NaCl reabsorption. Therefore, the hypothesis that postdiuretic Na retention in humans contains a volume-independent component was tested. Normal volunteers were equilibrated to a 120 mmol/24 h Na intake. For the first protocol, subjects received, in random order, a placebo, bumetanide (B), or bumetanide accompanied by an infusion of an electrolyte solution at a rate adjusted to match urine flow and thereby to obviate Na losses (bumetanide plus volume replacement; B + VR). After the completion of B diuresis, there was a positive Na balance that restored 70% of the Na loss within 42 h. However, this positive Na balance was prevented by volume replacement (B + VR). For the second protocol, subjects received, in random order, a placebo injection and a 100-mmol NaCl load (P + NaCl) or a bumetanide injection plus volume replacement in addition to a 100-mmol NaCl load (B + VR + NaCl). Over the ensuing 42 h, 94% of the load was eliminated when it was infused alone (P + NaCl). In contrast, only 9% was eliminated when it was given with bumetanide and volume replacement (B + VR + NaCl). It was concluded that postdiuretic Na retention in normal human subjects is due both to ECV depletion and to volume-independent Na retention manifest as an inability to excrete a modest NaCl load.(ABSTRACT TRUNCATED AT 250 WORDS)

A Symposium on Amphibian Declines and Habitat Acidification

A symposium was held 8 August 1991, at the annual meeting of the Society for the Study of Amphibians and Reptiles and The Herpetologists' League in University Park, Pennsylvania. The topic, Amphibian Declines and Habitat Acidification was selected for its relevance to the topical issues of a precipitous drop in many amphibian populations, and possible causation by acidic atmospheric deposition. As organizers, we felt that a rigorous approach to these issues requires meticulous field documentation of population fluctuations and correlated environmental measures of pollution, along with an experimental ecotoxicological analysis of possible anthropogenic causation. Because of the potential for large-scale environmental change acting synergistically with pollution across landscapes, the experimental elucidation of cause and effect will be extremely difficult. It appears that some amphibian populations fluctuate in an episodic fashion, but there are no long-term data bases adequate to determine whether particular declines are uniequivocally due to acidic deposition from non-point sources, other anthropogenic causes, natural causes, or interactions among them. This series of papers deals with the effects of acidic waters and soils on amphibians in England and North America. It is very clear that acidic habitats of natural and polluted origin exclude certain species and cause sub-lethal and lethal effects. However, no data are at hand which show directly that anthropogenic acidification causes amphibian populations to decline. There is consid- erable interest in the development of bioindicators of habitat decline. Net loss of body sodium and the embryonic curling defect in amphibians are examples of the best of such direct bioassays in acidified aquatic and terrestrial habitats. There is a strong need for standardization of test conditions so that better comparisons can be made among results from laboratories in different geographic regions. We recommend that a number of sites be chosen for long-term (10 year minimum) study of the relation between amphibian population cycles and anthropogenic change. This research would provide data not only specifically pertinent to the issue of amphibian declines, but would also provide valuable tests of the usefulness of amphibians as general bioindicators of ecosystem decline in response to anthropogenic stress. These issues are complex and are not amenable to quick solutions. A sustained commitment is needed by researchers and funding agencies to provide long-term monitoring and rigorous experimental tests of the causes of any declines in especially sensitive biotic components of ecosystems.

Enterotoxic effects of Aeromonas sobria haemolysin in a rat jejunal perfusion system identified by specific neutralization with a monoclonal antibody.

Investigations into the pathogenesis of Aeromonas diarrhoea have demonstrated that several different cell-free products of motile aeromonads show enterotoxic activity in suckling mouse, rat, and rabbit assay systems. The relative contributions made by separate cytotoxic and cytotonic activities in the mixture produced by in vitro culture remains unresolved. Using a modified rat jejunal perfusion assay, we have studied the effects of A. sobria culture filtrates containing defined levels of haemolytic and cytotoxic activity and immunoreactivity for anti-cholera toxin. This material induced net water, potassium, and sodium loss with a rapid onset (less than 5 min) that was readily differentiated from the effects of purified cholera toxin (greater than 15 min). In filtrates containing up to 128 haemolytic and cytotoxic units of activity, the enterotoxic activity was neutralized by an anti-haemolysin/cytotoxin monoclonal antibody. No specific histological changes could be found in preparations perfused with enterotoxic material for up to 65 min. These findings indicate that the cytotoxic/haemolytic component of A. sobria culture filtrate is the dominant enterotoxic activity.

Plasma volume, osmolarity, total protein and electrolytes during treadmill running and cycle ergometer exercise.

While haemoconcentration due to loss of plasma volume is well established during cycling, the existence of similar changes during running remains contentious. This study compared the changes in plasma volume and associated blood indices during 60 min of running and cycling at the same relative intensity (approximately 65% VO2max), with all changes referenced to blood indices obtained after 30 min seated at rest on a cycle ergometer. Plasma osmolarity increased similarly with both forms of exercise but was less than predicted for water loss alone, such that there was a net loss of sodium during exercise and of potassium postexercise, with essentially no loss of protein. Plasma volume decreased similarly (approximately 6.5%) in both exercise trials, but while that with cycling was initiated by exercise itself and was essentially maximal within 5 min, the reduction in plasma volume in the running trial was induced by adopting the upright posture and was complete before exercise began. These data would indicate that different mechanisms are responsible for the changes in plasma volume induced by running and cycling, while the similarity of change would suggest that there is a lower limit to any reduction in plasma volume, regardless of mechanism. Furthermore, the observation that the changes in plasma volume were complete before or early in exercise, would imply that oral water ingestion during prolonged exercise, which is essential for thermoregulation, may be more concerned with homeostasis of extravascular water rather than plasma volume.

Loss of Sodium from Mung Bean Shoots to Saline Root Media

AbstractIn a pulse chase experiment, seedlings of mung beans were loaded with radio‐active isotope (22Na) in 50 mM NaCl solution for 4 days. Individual seedlings were transferred to non‐labelled salt solution and the retranslocation of sodium was studied over a period of one week. Growth of seedlings was also studied during this period. Net loss of sodium was observed from roots and stem to the root medium. The leaves accumulated some of the retranslocated sodium as well. The rates of sodium retranslocation and other relevant data are discussed in this paper.