Diuresis in the cabbage white butterfly, Pieris brassicae: Water and ion regulation and the rôle of the hindgut

The significance of diuresis in the water and ion balance of newly emerged Pieris was examined by comparing the composition of haemolymph and urine during diuresis. The high potassium content of the urine results in a marked increase in the Na/K ratio of the haemolymph. The haemolymph osmolarity is well regulated, in spite of the very hypo-osmotic urine. By means of an isolated preparation of the ileum, it was shown that rapid resorption of potassium ions by this part of the hindgut is responsible for the low osmolarity of the urine.     

Electrolyte excretion in alcohol preferring and alcohol avoiding rats

Water and electrolyte metabolism was studied in alcohol preferring (AA) and alcohol avoiding (ANA) rats. During water diuresis AA rats had higher Mg, cAMP, creatinine and inorganic phosphate excretion, but lower urine and urinary protein output. During ethanol diuresis AA rats had lower Na, K, Ca, protein and urine output, but higher cAMP and inorganic phosphate excretion. Ethanol increased K, Ca and urine output in ANA rats only. A slight increase of blood pH was observed only in AA rats. Before ethanol ANA rats had higher plasma Ca concentration. Plasma aldosterone level was higher in AA rats. High salt excretion of ANA rats may lead them to prefer salt containing energy sources and therefore to avoid ethanol. On the other hand, renal salt conservation in AA rats may lead them to prefer ethanol.     

Hypercalciuria Relative to Total Solutes in Nephrolithiasis

Urines obtained from normal controls, from patients with calcium-containing renal stones, and from acutely ill patients suffering from various other renal or electrolyte disorders were analysed for Na, K, NH₄, Ca, Mg, inorganic phosphate and sulphate, pH, and osmolality.The stone-formers'' urines were found to be characterized by hypercalciuria relative to Na, K, Mg, SO₄, osmolality, and ionic strength. Hypercalciuria relative to osmolality was a more consistent finding than hypercalciuria relative to Na.These findings are in keeping with the supposition that calcium-containing renal stones occur in urine saturated with calcium salts.     

The effects of desiccation and rehydration on the lone star tick

This study describes the effects of desiccation and rehydration on the water content, haemolymph volume (per cent), osmolarity, and concentrations of Na, K, Mg, and Ca in the haemolymph of the lone star tick, Amblyomma americanum.The water content percentages of ‘severely desiccated’, ‘moderately’ and ‘fully hydrated’ ticks were 46·0, 52·8, and 60·3 per cent respectively. The lowest and highest of these were near the minimum and maximum possible.The haemolymph volume (per cent) of ‘severely desiccated’ ticks was regulated near the level of ‘moderately hydrated’ ticks despite significant decreases in total body water content and increases in osmolarity and concentration of sodium. Conversely, the change from ‘severely desiccated’ to ‘moderately hydrated’ ticks can be viewed as causing an increase in total body water, decrease in blood osmolarity and sodium, but little change in haemolymph volume (per cent).Most of the water taken up by ‘moderately hydrated’ ticks (while becoming ‘fully hydrated’) was added to the haemolymph. At the same time, there was little change in the blood osmolarity or haemolymph concentration of sodium. Conversely, the change of ‘fully’ to ‘moderately hydrated’ ticks was marked by a substantial loss of haemolymph volume (per cent) but little change in osmolarity and concentration of sodium.The concentration of potassium was regulated over the full range of desiccating and hydrating conditions. The lone star tick appeared less able to regulate its haemolymph concentrations of Ca and Mg; both fluctuated at the same rate, but inversely as the haemolymph volume (per cent).It appears that a carefully controlled movement of solutes (Na the predominant cation) between haemolymph and non-haemolymph tissue is intimately linked with haemolymph volume regulation and movement of water into the haemolymph during hydration.     

Electrolyte changes in plasma and urine of athletes during acute and rigorous bed rest and ambulatory conditions

Rigorous bed rest (RBR) induces significant electrolyte changes, but little it is not known about the effect of acute bed rest (ABR) (i.e., abrupt confinement to a RBR). The aim of this study was to measure urinary and plasma electrolyte changes during ABR and RBR conditions. The studies were done during 3 d of a pre-bed-rest (BR) period and during 7 d of an ABR and RBR period. Thirty male trained athletes aged, 24.4 ± 6.6 yr were chosen as subjects. They were divided equally into three groups: unrestricted ambulatory control subjects (UACS), acute-bed-rested subjects (ABRS), and rigorous-bed-rested subjects (RBRS). The UACS group experienced no changes in professional training and daily activities. The ABRS were submitted abruptly to a RBR regimen and without having any prior knowledge of the exact date and time when they would be subjected to an RBR regimen. The RBRS were subjected to an RBR regime on a predetermined date and time known to them from the beginning of the study. Sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and phosphate (P) in plasma and urine, plasma renin activity (PRA) and plasma aldosterone (PA), physical characteristics, peak oxygen uptake, and food and water intakes were measured. Urinary Na, K, Ca, Mg, and P excretion and plasma Na, K, Mg, Ca, and P concentration, PRA, and PA concentration increased significantly (p ≤ 0.01), whereas body weight, peak oxygen uptake, and food and water intakes decreased significantly in the ABRS and RBRS groups when compared with the UACS group. However, urinary and plasma Na, K, Mg, P, and Ca, PRA, and PA values increased much faster and were much greater in the ABRS group than in the RBRS group. Plasma and urinary Na, K, Ca, Mg, and P, PRA and PA levels, food and water intakes, body weight, and peak oxygen uptake did not change significantly in the UACS group when compared with its baseline control values. It was shown that RBR and ABR conditions induce significant increases in urinary and plasma electrolytes; however, urinary and plasma electrolyte changes appeared much faster and were much greater in the ABRS group than the RBRS group. It was concluded that the more abruptly motor activity is ended, the faster and the greater the urinary and plasma electrolyte change.     

Availability of Ca from Ca45SO4 in a highly saline-sodic soil

Summary Application of gypsum (tagged Ca⁴⁵SO₄.2H₂O) caused a considerable increase in dry matter yield and content of Ca, Ca⁴⁵, Mg and K and Ca:Na and (Ca+Mg): (Na+K) ratios and a decrease in the content of Na, N and P in dhaincha tops. There was a considerable increase in the total uptake of Ca, Mg, Na, K, N, P and Ca⁴⁵ by plant tops in response to gypsum. Contribution of Ca from applied Ca⁴⁵SO₄ varied from 78.3 to 84.7 per cent of the total Ca in plant tops, whereas, its uptake from this source varied from 52.18 to 98.73 me per 100 g plant tops. re]19720705     

Angiotensin-converting enzyme and metals in untreated essential hypertension

Hpertension is an important health problem throughout the world and a risk factor for many diseases. Angiotensin-converting enzyme (ACE), a component of the renin-angiotensin system, has an important role in the regulation of blood pressure. Zinc (Zn), a trace element with important biological functions, is located in the catalytic site of ACE. Calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K) also appear to be involved in hypertension pathogenesis. In this study, plasma ACE activities and Ca_t, Ca_i, Mg, Na, K, and plasma/erythrocyte Zn levels of 20 untreated patients with essential hypertension and 28 helthy individuals were evaluated. Plasma ACE activities (p<0.05) and erythrocyte Zn concentrations (p<0.001) were significantly higher in patients with essential hypertension than values of the control group. No significant difference was found between plasma Zn concentrations of the groups (p>0.05). Plasma Ca_t (p<0.001) and Mg levels (p<0.05) in essential hypertension were significantly lower than those of controls. Plasma Na, K, and Ca_i levels remained normal in essential hypertension. There are complex associations between metals and arterial pressure. Ca and Mg deficiencies seem to be associated with increased prevalence of hypertension. Increases in erythrocyte Zn may have a future potential use for diagnosis of hypertension.     

High urine flow rate increases prostaglandin E excretion in the conscious dog

Although previous studies from this and other laboratories have shown that urinary prostaglandin E excretion (U_PGEV) can vary independent of urine flow rate, recent studies during water diuresis in the conscious dog have suggested that high urine flow rate per se may increase U_PGEV. To examine the effect of urine flow rate on U_PGEV we administered either mannitol, chlorothiazide or Ringer's solution to mongrel dogs and measured U_PGEV. During anesthesia neither mannitol or chlorothiazide increased U_PGEV. There was, however, a consistent increase with all three agents in awake animals. This increase in U_PGEV was independent of alterations in glomerular filtration rate. There was a consistent increase in urinary sodium excretion and decrease in urinary osmolality with all three agents. The changes in PGE, however, were similar to those found during water diuresis when no increase in sodium excretion was found. It is not presently clear whether these findings reflect a true increase in renal PGE synthesis due to some change in flow or pressure within the renal medulla or rather represent unchanged PGE synthesis by renal tubular cells, the high tubule fluid flow rate causing increased entry into the tubular lumen in contrast to the renal interstitium.     

Regulation of intracellular creatine in erythrocytes and myoblasts: Influence of uraemia and inhibition of Na,K-ATPase

The regulation of intracellular creatine concentration in mammalian cells is poorly understood, but is thought to depend upon active sodium-linked uptake of creatine from extracellular fluid. In normal human erythrocytes, creatine influx into washed cells was inhibited by 40 per cent in the absence of extracellular sodium. In washed cells from uraemic patients, sodium-independent creatine influx was normal, whereas the sodium-dependent component of creatine influx was 3·3 times higher than normal, possibly relecting the reduced mean age of uraemic erythrocytes. In spite of this, the intracellular creatine concentration was no higher than normal in uraemic erythrocytes, implying that some factor in uraemic plasma in vivo inhibits sodium-dependent creatine influx. Both in normal and uraemic erythrocytes, the creatine concentration was 10 times that in plasma, and the concentration in the cells showed no detectable dependence on that in plasma, suggesting that the intracellular creatine concentration is controlled by an active saturable process. Active sodium-dependent accumulation of creatine was also demonstrated in L6 rat myoblasts and was inhibited when transport was measured in the presence of 10^?4M ouabain or digoxin, implying that uptake was driven by the transmembrane sodium gradient. However, when creatine influx was measured immediately after ouabain or digoxin had been washed away, it was higher than in control cells, suggesting that Na,K-ATPase and/or sodium-linked creatine transport are up-regulated when treated with inhibitors of Na,K-ATPase.     

Effects of Intracellular Adenosine-5''-diphosphate and Orthophosphate on the Sensitivity of Sodium Efflux from Squid Axon to External Sodium and Potassium

A study was made of sodium efflux from squid giant axon, and its sensitivity to external K and Na. When sodium efflux from untreated axons was strongly stimulated by K_o, Na_o was inhibitory; when dependence on K_o was low, Na_o had a stimulatory effect. Incipient CN poisoning or apyrase injection, which produces high intracellular levels of ADP¹ and P_i, rendered sodium efflux less dependent on external K and more dependent on external Na. Injection of ADP, AMP, arginine, or creatine + creatine phosphokinase, all of which raise ADP levels without raising P_i levels, had the same effect as incipient CN poisoning. P_i injection had no effect on the K sensitivity of sodium efflux. Axons depleted of arginine and phosphoarginine by injection of arginase still lost their K sensitivity when the ATP:ADP ratio was lowered and regained it partially when the ratio was raised. Rough calculations show that sodium efflux is maximally K_o-dependent when the ATP:ADP ratio is about 10:1, becomes insensitive to K_o when the ratio is about 1:2, and is inhibited by K_o when the ratio is about 1:10. Deoxy-ATP mimicked ADP when injected into intact axons. Excess Mg, as well as P_i, inhibited both strophanthidin-sensitive and strophanthidin-insensitive sodium efflux. An outline is presented for a model which might explain the effects of ADP, P_i and deoxy-ATP.     

Relationships between plasma composition and parotid salivary composition and secretion rates in the potoroine marsupials,Aepyprymnus rufescens and Potorous tridactylus

Summary Parotid salivation was investigated in two species of potoroine marsupial, Aepyprymnus rufescens and Potorous tridactylus to ascertain flow rates and composition, the buffer capacity of the saliva with respect to possible dependence of these animals on foregut fermentation, and the similarity of anion excretion patterns to those of the kangaroo parotid. Under anaesthesia neither species secreted spontaneously and secretion was stimulated by intravenous infusion of carbachol, bethanechol and isoprenaline. Under cholinergic stimulation in Aepyprymnus, the concentrations of Na, Cl, HCO₃ and osmolality were positively correlated with flow rate, whereas K, Mg, PO₄, H⁺ and urea were negatively correlated with flow. Amylase activity and the concentrations of protein and Ca showed no consistent relation to flow. Relative to Aepyprymnus, saliva of Potorous had much lower amylase activity and amylase activity per gram protein, lower concentrations of urea and Ca, and higher Na. Protein, K and HCO₃ concentrations were similar in both species. The plasma of both species had similar electrolyte concentrations, but Potorous had lower protein, urea, osmolality and amylase activity. Plasma amylase activity in Aepyprymnus rose during cholinergic stimulation to levels in excess of rodent plasma. Isoprenaline infusion in Aepyprymnus increased salivary amylase activity and concentrations of protein, Ca, HCO₃ and PO₄, and reduced the concentrations of Cl and H⁺. The patterns of anion excretion in the two potoroine marsupials were dissimilar to those of the kangaroo parotid suggesting that parotid fluid secretion is not HCO₃ driven to the same extent as that of kangaroos. Buffer anion concentrations and secretion rates were similar to koalas and low relative to kangaroos, indicating that these potoroines do not rely on foregut fermentation.Abbreviations bw body weight - SEM standard error of mean - VFA volatile fatty acids     

Effects of a parasite-induced nephritis on osmoregulation in the common carp Cyprinus carpio

Carp Cyprinus carpio infected with the haemoflagellate Trypanoplasma borreli undergo progressive nephritis associated with a destruction of approx. 40% of the nephric tubules. In an attempt to analyse the effect of the nephritis on the osmoregulation of affected carp, the clinical chemical properties of plasma and urine samples were analysed. Parasitised carp excreted greater amounts of electrolytes in their urine than uninfected carp which excreted highly diluted urine with an osmolality of about 10% of plasma osmolality. During the course of the infection, urine osmolality increased up to 26% of plasma osmolality by Day 21 post-infection (p.i.). The plasma:urine ratio of Na+ also increased, while concomitant losses of Mg2+, Ca2+, K+ and inorganic phosphate were less pronounced. Infected carp were able to maintain a normal solute balance in their plasma. Plasma hydration (indicated by decreased protein contents) occurred on Day 21 p.i. Our data indicate that in T. borreli-infected carp, reabsorption processes of the distal renal tubule were disturbed, while secretory and absorption processes in the proximal tubule appeared to be less affected. In addition, infected carp were able to compensate their increased ion losses, probably by (energy-consuming) active absorption processes. The energy budget of infected carp was additionally affected by a substantial direct consumption of plasma glucose by the parasite.     

Separating multiple, short-term, deleterious effects of saline solutions on the growth of cowpea seedlings

? Reductions in plant growth as a result of salinity are of global importance in natural and agricultural landscapes. ? Short-term (48-h) solution culture experiments studied 404 treatments with seedlings of cowpea (Vigna unguiculata cv Caloona) to examine the multiple deleterious effects of calcium (Ca), magnesium (Mg), sodium (Na) or potassium (K). ? Growth was poorly related to the ion activities in the bulk solution, but was closely related to the calculated activities at the outer surface of the plasma membrane, {I(z)}?°. The addition of Mg, Na or K may induce Ca deficiency in roots by driving {Ca2+}?° to < 1.6 mM. Shoots were more sensitive than roots to osmolarity. Specific ion toxicities reduced root elongation in the order Ca2+ > Mg2+ > Na+ > K+. The addition of K and, to a lesser extent, Ca alleviated the toxic effects of Na. Thus, Ca is essential but may also be intoxicating or ameliorative. ? The data demonstrate that the short-term growth of cowpea seedlings in saline solutions may be limited by Ca deficiency, osmotic effects and specific ion toxicities, and K and Ca alleviate Na toxicity. A multiple regression model related root growth to osmolarity and {I(z)}?° (R2=0.924), allowing the quantification of their effects.     

Na+ Recirculation and Isosmotic Transport

The Na(+) recirculation theory for solute-coupled fluid absorption is an expansion of the local osmosis concept introduced by Curran and analyzed by Diamond & Bossert. Based on studies on small intestine the theory assumes that the observed recirculation of Na(+) serves regulation of the osmolarity of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal NaCl by sucrose as well as the linear dependence of volume absorption on luminal NaCl concentration. Analysis of solvent drag on Na(+) in tight junctions provides explanation for the surprisingly high metabolic efficiency of Na(+) reabsorption. The model predicts and explains low metabolic efficiency in diluted external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and < or = 1 mOsm in proximal tubule. Truly isosmotic transport demands a Na(+) recirculation of 50-70% in small intestine but might be barely measurable in proximal tubule. The model fails to reproduce a certain type of observations: The reduced volume absorption at transepithelial osmotic equilibrium in AQP1 knockout mice, and the stimulated water absorption by gallbladder in diluted external solutions. Thus, it indicates cellular regulation of apical Na(+) uptake, which is not included in the mathematical treatment.     

Dose response relation of the renal effects of PGA1, PGE2, and PGF2α in dogs

The effects of the three prostaglandins A₁, E₂, and F_2α on renal blood flow, glomerular filtration rate (GFR), fluid excretion, and urinary output of Na, K, Ca, Cl, and solutes were evaluated at a dose range of 0.01 – 10 μg/min. The prostaglandins were infused into the renal artery of dogs. GFR was not significantly altered by the PGs. PGA₁ increased renal blood flow by approximately of the control at 0.01 μg/min without dose dependence at higher infusion rates. It had only little effects which were not dose dependent on fluid and electrolyte output. The effects of PGE₂ on renal blood flow, fluid, sodium, and chloride excretion were dose dependent with a steep slope of the dose response curve between 0.1 and 1.0 μg/min. Blood flow was increased maximally by 80 %, urine volume by more than 400 %. PGF_2α had no effect on renal blood flow, whereas urinary output was increased to approximately the same maximal level as by E₂ although ten times higher doses were needed. Potassium excretion was less influenced than the excretion of Na and Cl and osmolar clearance was less increased than urine volume by all three prostaglandins.It is concluded that if a PG is involved in the regulation of the renal fluid or electrolyte excretion it is likely to be of the PGE-type. A PGA could only be involved in regulation of renal hemodynamics, whereas PGF although effective in the kidney exerts its effects at doses too high to have physiological significance.     

Mechanisms mediating the diuretic and natriuretic actions of the incretin hormone glucagon-like peptide-1

Glucagon-like peptide-1 (GLP-1) is a gut incretin hormone considered a promising therapeutic agent for type 2 diabetes because it stimulates beta cell proliferation and insulin secretion in a glucose-dependent manner. Cumulative evidence supports a role for GLP-1 in modulating renal function; however, the mechanisms by which GLP-1 induces diuresis and natriuresis have not been completely established. This study aimed to define the cellular and molecular mechanisms mediating the renal effects of GLP-1. GLP-1 (1 μg·kg(-1)·min(-1)) was intravenously administered in rats for the period of 60 min. GLP-1-infused rats displayed increased urine flow, fractional excretion of sodium, potassium, and bicarbonate compared with those rats that received vehicle (1% BSA/saline). GLP-1-induced diuresis and natriuresis were also accompanied by increases in renal plasma flow and glomerular filtration rate. Real-time RT-PCR in microdissected rat nephron segments revealed that GLP-1 receptor-mRNA expression was restricted to glomerulus and proximal convoluted tubule. In rat renal proximal tubule, GLP-1 significantly reduced Na(+)/H(+) exchanger isoform 3 (NHE3)-mediated bicarbonate reabsorption via a protein kinase A (PKA)-dependent mechanism. Reduced proximal tubular bicarbonate flux rate was associated with a significant increase of NHE3 phosphorylation at the PKA consensus sites in microvillus membrane vesicles. Taken together, these data suggest that GLP-1 has diuretic and natriuretic effects that are mediated by changes in renal hemodynamics and by downregulation of NHE3 activity in the renal proximal tubule. Moreover, our findings support the view that GLP-1-based agents may have a potential therapeutic use not only as antidiabetic drugs but also in hypertension and other disorders of sodium retention.     

Different sensitivity of ATP + Mg + Na (I) and Pi + Mg (II) dependent types of ouabain binding to phospholipase A2

Summary The effect of phospholipase A₂ and of related agents on ouabain binding and Na,K-ATPase activity were studied in intact and detergent-treated membrane preparations of rat brain cortex and pig kidney medulla. It was found that phospholipase A₂ (PLA₂) may distinguish or dissociate ouabain binding complexes I (ATP+Mg+Na) and II (P_i+Mg), stimulating the former and inhibiting the latter. Procedures which break the permeability barriers of vesicular membrane preparations, such as repeated freezing-thawing, sonication or hypoosmotic shock failed to mimic the effect of PLA₂, indicating that it was not acting primarily by opening the inside-out oriented vesicles. The detergent digitonin exhibited similar effects on ouabain binding in both ATP+Mg+Na and P_i+Mg media. Other detergents were ineffective.The ability of PLA₂ to distinguish between ouabain binding type I and II can be manifested even in SDS-treated, purified preparations of Na,K-ATPase. The number of ATP+Mg+Na-dependent sites is unchanged, while the P_i+Mg-dependent sites are decreased in number in a manner similar to that seen in original membranes. This inhibition is completely lost in the reconstituted Na,K-ATPase system, where the ATP- as well as P_i-oriented ouabain sites are inhibited by PLA₂.     

Muscle water and electrolytes following varied levels of dehydration in man.

In an effort to assess the effects of dehydration on the content of water and electrolytes (Na+, K+, Cl-, and Mg2+) in plasma and muscle tissue, eight men exercised in the heat (39.5 degrees C, 25%). Blood urine, and muscle biopsy samples were obtained before exercise and after the subjects had reduced their body weight by 2.2, 4.1, and 5.8%. On the average, plasma and muscle water (H2Om) contents were found to decline 2.4 and 1.2% for each percent decrease in body weight. Muscle sodium (Na+m) and chloride (Cl-m) content remained unchanged with dehydration, while muscle magnesium (Mg2+m) declined 12% as a result of the 5.8% dehydration. In terms of intracellular concentrations, K+i increased 7.2 and 10.6% at the 2.2 and 4.1% dehydration levels, respectively. Calculations of the resting membrane potential suggest that the water and electrolyte losses observed in these studies do not significantly alter the excitability of the muscle cell membrane.     

THE PENETRATION OF AMMONIA INTO FROG MUSCLE

1. A study was made of the electrolyte changes which occur when frog muscles are immersed in a Ringer solution with 1/5 of the Na replaced by NH₄Cl. Analyses were made in the solution and in the muscles for K and NH₃, and the muscles were also analyzed for Cl, HCO₃, and Na. Control muscles were immersed in normal Ringer''s solution and similarly analyzed. 2. The amount of ammonia taken up was about equal to the K and Na lost. There was also a small increase in chloride content. The bicarbonate content was the same in both experimental and control muscles, indicating no change in the muscle pH due to the NH₃ which penetrated. An increased loss of K due to the penetration of NH₃ was also demonstrated by the use of radioactive K. 3. After 5 hours, the concentration of ammonia per gram of muscle is about the same as the concentration in the solution. After 4 or 5 days, the concentration in the muscle is about 1.5 times that in the solution. The inside to outside NH₃ ratio is about equal to the corresponding H ion ratio, but is much less than the K ratio. 4. The rate of penetration of the NH₃ is increased by a rise of temperature, by stirring the solution, and by decrease in the concentration of Na, K, Ca, or Mg in the solution; it is decreased by increasing the size of the muscles or by killing them with chloroform or boiling. 5. Liver, smooth muscle, skin, and kidney, in a few experiments, behaved much like muscle except that there was a formation of urea in the case of liver. 6. The injection of NH₄Cl into anesthetized cats causes an increase in the level of K in the blood plasma.     

Effect of farm yard manure on the availability of Ca from Ca45CO3 in a sodic soil (ESP 77.7)

Summary Application of FYM caused a gradual increase in the dry weight of dhaincha (Sesbania aculeata Pers.) tops. It also caused a gradual increase in the content of Mg and K and a decrease in the content of Ca, Na, N and P in dhaincha tops. Increase in Ca: Na ratio was more steeper than (Ca+Mg): (Na+K) ratio. Total uptake of Ca, Mg, K, N and P increased and that of Na decreased in response to FYM. Contribution of Ca from Ca⁴⁵CO₃ did not differ much at different levels of FYM and it was less than 6 per cent of total Ca in plant tops in all the treatments. re]19721017