pyrophosphate and Urinary-Calculi

Urine contains compounds that modulate the nucleation, growth and aggregation of crystals as well as their attachment to renal epithelial cells. These compounds may function to protect the kidneys against: 1, the possibility of crystallization in tubular fluid and urine, which are generally metastable with respect to calcium salts, 2, crystal retention within the kidneys thereby preventing stone formation and 3, possibly against plaque formation at the nephron basement membrane. Since oxalate is the most common stone type, the effect of various modulators on calcium oxalate (CaOx) crystallization has been examined in greater details. Most of the inhibitory activity resides in macromolecules such as glycoproteins and glycosaminoglycans while nucleation promotion activity is most likely sustained by membrane lipids. Nephrocalcin, Tamm-Horsfall protein, osteopontin, urinary prothrombin fragment 1, and bikunin are the most studied inhibitory proteins while chondroitin sulfate (CS), heparan sulfate (HS) and hyaluronic acid (HA) are the best studied glycosaminoglycans. Crystallization modulating macromolecules discussed here are also prominent in cell injury, inflammation and recovery. Renal epithelial cells on exposure to oxalate and CaOx crystals produce some of the inflammatory molecules such as monocyte chemoattractant protein-1 (MCP-1) with no apparent role in crystal formation. In addition, macrophages surround the CaOx crystals present in the renal interstitium. These observations indicate a close relationship between inflammation and nephrolithiasis.

Topics: Calcium Oxalate; Calcium Phosphates; Citric Acid; Crystallization; Diphosphates; Diphosphonates; Glycosaminoglycans; Humans; Membrane Lipids; Proteins; Urinary Calculi

A review on the knowledge of the precipitation of calcium phosphates and calcium oxalates is presented. The simultaneous presence of these solids in urinary stones may be originated, according to experimental conditions, from the homogeneous nucleation of one of them, followed by the heterogeneous nucleation of the other one.

Topics: Calcium Oxalate; Calcium Phosphates; Carbonates; Chemical Precipitation; Crystallization; Diphosphates; Humans; Ions; Magnesium; Solubility; Urinary Calculi

Topics: Adsorption; Calcium Oxalate; Citrates; Crystallization; Diphosphates; Glycosaminoglycans; Humans; Macromolecular Substances; Magnesium; Proteins; Solubility; Urinary Calculi

Topics: Adult; Animals; Benzothiadiazines; Calcium; Chemical Precipitation; Child; Citrates; Crystallization; Diphosphates; Diuretics; Female; Humans; Kidney Calculi; Magnesium; Male; Methylene Blue; Milk; Oxalates; Particle Size; Phosphates; Phosphorus; Sodium Chloride Symporter Inhibitors; Solubility; Urinary Calculi

Topics: Acidosis, Renal Tubular; Bacterial Infections; Citrates; Crystallization; Cystinuria; Diphosphates; Female; Gastrointestinal Diseases; Humans; Hypercalcemia; Hyperparathyroidism; Magnesium; Male; Metabolism, Inborn Errors; Mucoproteins; Oxalates; Quaternary Ammonium Compounds; Sarcoidosis; Solubility; Uric Acid; Urinary Calculi; Vitamin D; Xanthine Oxidase

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Calcium, Dietary; Chelating Agents; Colloids; Coloring Agents; Diet; Diphosphates; Enzymes; Glycosaminoglycans; Hydrogen-Ion Concentration; Magnesium; Mucoproteins; Peptides; Phosphorus; Poaceae; Seasons; Sex Factors; Urinary Calculi; Vitamin A Deficiency; Water-Electrolyte Balance

Topics: Calcium; Cystinuria; Diphosphates; Humans; Magnesium; Oxalates; Phosphates; Urea; Urinary Calculi

Topics: Diphosphates; Humans; Urinary Calculi

An ICPMS method for the determination of phytic acid in human urine based on the total phosphorus measurement of purified extracts of phytic acid is described. Pretreatment of the sample is required to avoid interference in the ICPMS detection from other phosphorus compounds accompanying phytic acid in urine such as phosphate or pyrophosphate. This treatment consists of a simple filtration of the urine sample followed by complete separation of phytic acid from the mentioned phosphorus components using an anion-exchange solid-phase extraction. Separation/recovery conditions, optimized for standards of phytic acid prepared in water and artificial urine, were successfully applied to natural urine samples, resulting in adequate accuracy and precision. Linear range (0.02-0.6 mg of phytic acid L(-)(1)) and limit of detection (5 microg L(-)(1) phytic acid) are adequate for analysis of the usual amounts of phytic acid present in urine. Phosphate, pyrophosphate, and pH of urine samples at concentrations exceeding their normal physiological ranges do not affect the determination of phytic acid. Because of the simplicity, low sample requirement, and relatively high sample throughput (10 to 6 min per sample for runs between 50 and 100 samples, respectively), the present method presents the best alternative to current methods for phytic acid determination in urine. Results also show that the method is adequate for the differentiation of levels of phytic acid excretion from patients suffering from oxalocalcic urolithiasis and healthy controls, suggesting that low phytic acid concentrations in urine lead to elevated risk of oxalocalcic urolithiasis.

Topics: Case-Control Studies; Diphosphates; Humans; Hydrogen-Ion Concentration; Mass Spectrometry; Phosphates; Phytic Acid; Sensitivity and Specificity; Urinary Calculi

The effect of citrate and pyrophosphate on the stability of calcium oxalate dihydrate (COD) was studied in an aqueous solution over 7 days. COD was precipitated from 1.0 x 10(-2) mol/l calcium oxalate solution with the addition of citrate and/or pyrophosphate and separated by centrifugation immediately, 48 h and 7 days after the precipitation. The percentage of COD in the precipitate, determined by X-ray diffraction, increased with a rise in citrate or pyrophosphate concentration and reached > or =90% at a citrate concentration of 1.0 x 10(-3) mol/l or a pyrophosphate concentration of 2.0 x 10(-4) mol/l. The resulting COD was completely transformed into calcium oxalate monohydrate within 48 h when the precipitate was composed of <90% COD. Nearly pure COD produced with pyrophosphate was stable over 7 days while that with citrate underwent partial transformation within 48 h. An additive effect of citrate and pyrophosphate was found on the stability of COD. It was concluded that a pyrophosphate concentration above a critical point was sufficient to prevent solution-mediated transformation of COD, and this critical point might be lowered to the physiological range with the presence of citrate.

Topics: Calcium Oxalate; Chemical Precipitation; Citric Acid; Crystallization; Diphosphates; Drug Stability; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Particle Size; Solutions; Urinary Calculi; X-Ray Diffraction

Calcium oxalate crystal growth and aggregation leads to the formation of renal calculi. It is known to be inhibited by several compounds both in vitro and in vivo conditions. The present study highlights the inhibitory potential of sodium pentosan polysulphate (SPP), a semi-synthetic glycosaminoglycan (GAG) on calcium oxalate crystal growth in vitro. Its efficacy was compared with those of known inhibitors like pyrophosphate, heparin and chondroitin-4-sulphate. Of the above compounds pyrophosphate was found to be the most potent inhibitor. Among the GAGs, SPP exhibited 80% inhibitory activity as compared to heparin. A lesser degree of inhibition was observed with chondroitin-4-sulphate.

Topics: Calcium Oxalate; Chondroitin Sulfates; Crystallization; Depression, Chemical; Diphosphates; Heparin; Pentosan Sulfuric Polyester; Urinary Calculi

The nucleation and crystal growth of calcium oxalate (CaOx) were studied at pH 5.5 using turbidimetric measurements at 620 nm of suspensions produced by mixing calcium chloride and sodium oxalate (initial conditions: Ca, 3 x 10(-3) M; Ox, 0.5 x 10(-3) M). CaOx crystallization kinetics were defined first by the induction time ti and then by the slope of turbidity as a function of time during the interval corresponding to a correlation coefficient r2 > 0.99. The technique described requires only a small amount of material, is quick, convenient, and can be used to study inhibitors of CaOx crystallization by comparing ti and the rate of crystal growth in the presence and absence of inhibitors. The effects on CaOx crystal growth of several low molecular weight compounds, i.e. di- and tricarboxylic acids, were examined. The majority of these compounds were inhibitors of crystal growth, the greatest effect being seen with citric acid (50% inhibition in the presence of 1.5 x 10(-3) M citric acid), isocitric acid (50% inhibition in the presence of 0.75 x 10(-3) M isocitric acid) and pyrophosphate (30% inhibition in presence of 0.15 x 10(-3) M pyrophosphate). The inhibitors' behaviour regarding the medium was studied without any assumptions about their possible mechanisms of action. Measurements of ionized calcium before and after the reaction, as well as the observation of crystals by scanning electron microscopy, allowed us to formulate the hypothesis that the effect of citric acid and tartaric acid can be attributed mainly to ion pairing, in contrast to that of pyrophosphate and the other carboxylic acids.

Topics: Calcium; Calcium Oxalate; Citrates; Citric Acid; Crystallization; Diphosphates; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Ions; Isocitrates; Microscopy, Electron, Scanning; Models, Biological; Urinary Calculi

Between October 1988 and March 1990, 173 urinary stone patients (average age 38.3 years) were evaluated metabolically, especially with regard to urinary magnesium, pyrophosphate (Ppi) citrate and glycosaminoglycans (GAG). 25 healthy subjects served as controls. Inhibitory deficiency was found to be the most frequent causal factor in our series, with an incidence of 48.7% in first-time stone formers and 51.08% in recurrent urolithiasis (p less than 0.1). Deficient citrate levels were present in 46.56%, hypomagnesiuria in 24.4%, hypopyrophosphaturia in 10.7% and deficient GAG in 2.7% of the patients. Deficient urinary Ppi was seen in only 2.7% of the stone formers as the only metabolic defect, while deficient GAG was never the only causal factor. All 4 inhibitors showed no correlation with age, sex, activity of stone disease, stone weight and burden. There were no statistically significant differences with controls. We think that routine metabolic evaluation must be performed both in recurrent patients and first-time stone formers and must include urinary citrate and Mg determinations in every case. Urinary Ppi should be determined in selected cases and GAG determinations are irrational.

Topics: Adult; Child; Citrates; Citric Acid; Diphosphates; Female; Glycosaminoglycans; Humans; Magnesium; Male; Recurrence; Urinary Calculi

Struvite (MgNH4PO4.6H2O) crystals, the major mineral component of infectious urinary calculi, were produced in vitro by growth of a clinical isolate of Proteus mirabilis in artificial urine. P. mirabilis growth and urease-induced struvite production were monitored by phase contrast light microscopy and measurements of urease activity, pH, ammonia concentrations, turbidity, and culture viability. In the absence of pyrophosphate, struvite crystals appeared within 3-5 h due to the urease-induced elevation of pH and initially assumed a planar or 'X-shaped' crystal habit (morphology) characteristic of rapid growth. When pyrophosphate was present, initial precipitation and crystal appearance were significantly impaired and precipitates were largely amorphous. When crystals did appear (usually after 7 or 8 h) they were misshapen or octahedral in shape indicative of very slow growth. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) identified all crystals as struvite. Trace contaminates of carbonate-apatite (Ca10(PO4)6CO3) or newberyite (MgHPO4.H2O) were produced only in the absence of pyrophosphate. P. mirabilis viability and culture pH elevation were unaffected by the addition of pyrophosphate, whereas urease activity and ammonia concentrations were marginally reduced. Struvite could also be produced chemically by titration of the artificial urine with NH4OH. If pyrophosphate was present during titration, the same inhibitory effect on crystal growth occurred, so it is unlikely that urease inhibition is important. Lowering of pyrophosphate concentration from 13-0.45 mumol/l did not reduce its inhibitory activity so it is unlikely to act by chelating free Mg2+. We propose that pyrophosphate inhibits struvite growth principally through direct interference with the chemical mechanisms involved in crystal nucleation and growth, because of its effectiveness at very low concentrations.

Topics: Ammonia; Crystallization; Crystallography; Diphosphates; Drug Evaluation, Preclinical; Hemostatics; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Proteus mirabilis; Spectrophotometry, Infrared; Struvite; Urinary Calculi; Urine

The nucleating effect of hydroxyapatite (HAP) and the inhibitory effect of pyrophosphate (PPi) on calcium oxalate crystallization have been studied at different pH's in solution metastabely supersaturated with respect to calcium oxalate but saturated with respect to HAP. Crystallization was monitored by a decrease of calcium in the supernatant and formation products were calculated. At a pH above 6.0 already minimal HAP concentrations proved to be a suitable substrate for heterogeneous nucleation and growth of calcium oxalate. PPi showed a pronounced inhibitory effect on spontaneous as well as on HAP induced crystallization of calcium oxalate, this effect being highly pH dependent. HAP was found to neutralize the inhibitory effect of PPi in a molar ratio of 10:1.

Topics: Calcium Oxalate; Crystallization; Diphosphates; Durapatite; Humans; Hydrogen-Ion Concentration; Hydroxyapatites; In Vitro Techniques; Urinary Calculi

The possible inhibitors of heterogeneous nucleation were investigated. The effects of magnesium, pyrophosphate, citrate and Chondroitin Sulphate on calcium phosphate or uric acid heterogeneous nucleation of calcium oxalate were studied. It was found that whereas magnesium, pyrophosphate and citrate acted as effective inhibitors in the presence of calcium phosphate as heterogeneous nucleant, only chondroitin sulphate manifested important inhibitory effects when uric acid was the heterogeneous nucleant.

Topics: Calcium Oxalate; Calcium Phosphates; Chondroitin Sulfates; Citrates; Citric Acid; Crystallization; Diphosphates; Humans; Magnesium; Uric Acid; Urinary Calculi

In calcium lithiasis, inhibitors have a significant effect in reducing the crystallization process. This work evaluated orthophosphate in a group of patients with calcium oxalate lithiasis, and in a control group. The study of orthophosphate and pyrophosphate, showed differences between stone formers and the control group. These results could be attributed to a failure in the renal transformation of orthophosphate into pyrophosphate.

Topics: Diphosphates; Female; Humans; Kidney; Male; Phosphates; Urinary Calculi

The inhibitory capacity of pyrophosphate, citrate, magnesium and chondroitin sulphate was investigated, using the urine of 21 calcium oxalate stone-forming patients without metabolic alterations. The inhibitory effect of these substances was assessed by a combination of nephelometry (light scattering) and optical microscopy. The results showed that citrate and magnesium had an inhibitory effect in a significant number of cases. Pyrophosphate and chondroitin sulphate had a less marked effect. The main urinary lithogenic biochemical parameters of the patients were also studied to see if there was a relationship between them and the inhibitory capacity of the compounds.

Topics: Calcium Oxalate; Chondroitin; Chondroitin Sulfates; Citrates; Citric Acid; Crystallization; Diphosphates; Humans; Magnesium; Urinary Calculi

The excretion of inorganic pyrophosphate was studied in daily, fasting and postprandial urine specimens of normocalciuric and hypercalciuric patients with recurrent renal calcium stone disease (40 men and 40 women), and healthy controls (20 men and 20 women). Both populations were subdivided into younger (20 to 40 years old) and older (more than 40 years old) individuals. In general, there was a tendency towards higher urinary pyrophosphate excretion with increasing age (both sexes and all groups studied), and lower excretion in women than in men. The urinary pyrophosphate excretion rate was unchanged in daily and fasting urine specimens of the younger male normocalciuric and idiopathic hypercalciuric stone patients, whereas in the daily and postprandial urine of younger women the median excretion rate was reduced (controls versus normocalciuric plus idiopathic hypercalciuric subjects, 3 versus 1 mumol., p less than 0.05). In contrast, in older men urinary pyrophosphate was reduced in daily specimens (controls versus normocalciuric plus idiopathic hypercalciuric subjects, 55 versus 33 mumol., p less than 0.05) but it was unchanged in fasting urine specimens. In older women no change was detectable in any of the 3 urine portions. Factorization of urinary pyrophosphate for the associated urinary creatinine did not alter these results substantially, and the presence of renal stones did not modify pyrophosphate excretion significantly. Urinary pyrophosphate was correlated significantly with urinary volume, citrate and phosphorus. We conclude that only subclassification of stone patients with respect to sex, age and type of calciuria, and consideration of additional urine portions besides the daily urine may help to uncover states of urinary pyrophosphate deficit. On the basis of the data, we recommend that clinically relevant studies on inhibitory effects of urinary pyrophosphate on the nucleation and growth of crystals and stones should be done preferentially in urine portions with a proved pyrophosphate deficit.

Topics: Adult; Aged; Aging; Calcium; Diphosphates; Fasting; Female; Food; Humans; Male; Middle Aged; Recurrence; Sex Factors; Urinary Calculi

Opinions vary on the effects produced by urinary inhibitors of crystallisation. We describe a simple method for studying inhibitory effects in urine based on nephelometry and optical microscopy. It was concluded that the inhibitory effect of a given substance on calcium oxalate crystallisation depends on the particular sample of urine being examined and that the most effective inhibitor can be determined only by studying the urine of each patient individually.

Topics: Calcium Oxalate; Chondroitin; Chondroitin Sulfates; Citrates; Crystallization; Diphosphates; Humans; Magnesium; Nephelometry and Turbidimetry; Urinary Calculi

The effect of stone growth inhibitors (citrate, pyrophosphate, ethane diphosphonate, methane diphosphonate, chondroitin sulfate A, chondroitin sulfate C, heparin and ribonucleic acid) on crystal-membrane interactions of whewellite, weddellite, apatite, brushite, struvite, uric acid, monosodium urate and quartz (control) stones was quantitated. As a model for the initial retention of microcrystals by kidney epithelial membranes, crystal-induced membranolysis of red blood cells served as a measure of crystal-membrane interactions. The inhibitors induced changes in hemolytic potential from approximately 320 per cent enhancement to 80 per cent inhibition. No inhibitor behaved the same way for all crystals studied. However, some crystals showed consistent trends in altered hemolytic potential in the presence of inhibitors. These crystals included weddellite and sodium urate, which were inhibited consistently, and apatite and quartz, which were enhanced consistently. Whewellite, uric acid, brushite and struvite exhibited mixed patterns in the altered hemolytic potentials owing to the inhibitors.

Topics: Calcium Oxalate; Chondroitin Sulfates; Citrates; Citric Acid; Crystallization; Diphosphates; Diphosphonates; Erythrocyte Membrane; Etidronic Acid; Hemolysis; Heparin; Humans; RNA; Urinary Calculi

An assay system for the measurement of the rate of Calcium Oxalate Monohydrate (COM) seed crystal growth in a metastable solution of calcium chloride and sodium oxalate containing traces of 14C-oxalic acid was used to assess the inhibitory activity of pyrophosphate (10(-5) M-10(-4) M), citrate (10(-4) M-10(-3) M) and urines of normal and pyridoxine deficient rats. Both pyrophosphate and citrate were strong inhibitors of COM crystal growth and caused a 50% decrease in crystal growth rate at 1.50 X 10(-5) M and 2.85 X 10(-4) M respectively. Normal rat urine strongly inhibited the COM crystal growth, while pyridoxine deficient animals showed a significant (p less than 0.01) decrease in mean inhibitory activity as compared to pair-fed controls. A lowered urinary inhibitory potential accompanied with hyperoxaluria and hypercalciuria, which is known to be associated with pyridoxine deficiency, may be a contributory risk of calcium oxalate crystallization and stone formation.

Topics: Animals; Calcium Chloride; Calcium Oxalate; Citrates; Citric Acid; Crystallization; Diphosphates; Male; Oxalates; Oxalic Acid; Rats; Rats, Inbred Strains; Solutions; Urinary Calculi; Urine; Vitamin B 6 Deficiency

The excretions and relative potencies of various macromolecular inhibitors of the crystallisation of calcium oxalate (CaOx) were measured in the urines of idiopathic calcium stone-formers and normal subjects. The stone-formers excreted significantly less polyanionic macromolecules in their urine than did the normals, the difference being attributable to the lower excretions of glycosaminoglycans (GAGS), ribonucleic acid (RNA) and Tamm-Horsfall mucoprotein (THM), all of which are precipitable with alcian blue. The relative potencies of the various inhibitors measured under 'whole urine equivalent' conditions using a batch crystallisation system, showed that the order of inhibitory activity towards CaOx crystal agglomeration was RNA greater than GAGS greater than THM greater than pyrophosphate (PPi). This paralleled the order of ability of these inhibitors to produce a high negative zeta potential on the surface of CaOx crystals.

Topics: Adult; Calcium Oxalate; Crystallization; Diphosphates; Glycosaminoglycans; Humans; Male; Middle Aged; Mucoproteins; Polyelectrolytes; Polymers; RNA; Urinary Calculi; Uromodulin

We describe a simple, rapid, and fully automated technique for measuring urinary pyrophosphates with a centrifugal analyzer (the ENI GEMSAEC). This technique depends on the enzymic magnesium-dependent reaction with UDPG pyrophosphorylase (UTP: alpha-D-glucose-1-phosphate uridylyl transferase, EC 2.7.7.9) and spectrophotometry of the NADPH formed in a combined system of phosphorylation and reduction. Many samples of urine can be analyzed quickly without pretreatment, with high sensitivity (1.3 mA/mumol of substrate) and good reproducibility. The mean within-run coefficient of variation for a 50 mumol/L pyrophosphate solution was 1.4%. We determined the optimum enzyme and magnesium concentrations necessary for use in a 4-min reaction. Because there is no inhibitory effect of chloride and phosphate ions, pyrophosphate can be measured directly in urine, without prior extraction. With this technique, the mean value (and SD) for urinary pyrophosphate excretion by 30 healthy subjects was 39.3 (SD 17.2) mumol/24 h.

Topics: Autoanalysis; Centrifugation; Clinical Enzyme Tests; Diphosphates; Humans; Kinetics; Magnesium; NADP; Reference Values; Urinary Calculi; UTP-Glucose-1-Phosphate Uridylyltransferase

A simple radiochemical method is proposed for the in vitro assay of the inhibitory activity of urine with respect to calcium oxalate crystal growth using [14C]oxalate as a tracer. The method shows an improved sensitivity over existing methods and indicates that citrate, pyrophosphate and chondroitin sulphate are active inhibitors of calcium oxalate crystal growth down to concentrations of 10(-5), 10(-7) and 10(-10) mol/l respectively. The inhibitory activity in the urines of 12 recurrent calcium stone-formers was significantly lower than in the urines of matched control subjects (P less than 0.01), confirming the clinical usefulness of the test.

Topics: Calcium Oxalate; Chondroitin Sulfates; Citrates; Crystallization; Diphosphates; Dose-Response Relationship, Drug; Humans; Urinary Calculi

The effect of urine, pyrophosphate (PPi), citrate and diphosphonate on the formation, the growth rate or the aggregation of calcium oxalate or calcium phosphate crystals was measured by 4 different methods. The degree of supersaturation and the area of crystal surface present in the test systems were found to be limiting factors for the action of inhibitors. Citrate and PPi proved to be important urinary inhibitors of the growth of calcium oxalate crystals. Comparison between stone formers and healthy controls revealed a significant lack of PPi in urine of male patients. The inhibitory effect of PPi in urine of healthy people was enhanced by unknown factors. This enhancement could not be found in about 60% of the stone patients. Problems relating to measurement and clinical importance of inhibitors are discussed.

Topics: Calcium Oxalate; Calcium Phosphates; Citrates; Crystallization; Diphosphates; Diphosphonates; Female; Humans; In Vitro Techniques; Male; Methods; Urinary Calculi; Urine

Topics: Benzothiadiazines; Calcium; Cellulose; Diet Therapy; Diphosphates; Diuretics; Humans; Intestinal Absorption; Ion Exchange; Phosphates; Recurrence; Sodium; Sodium Chloride Symporter Inhibitors; Urinary Calculi

Topics: Calcium Oxalate; Calcium Phosphates; Crystallization; Diphosphates; Diphosphonates; Humans; Oxalates; Phosphates; Urinary Calculi

A method is described for quantitatively determining the inhibitory activity of pure components, isolates, or mixtures of components (such as urine) on the growth of calcium oxalate crystals. Results with known calcium phosphate crystal growth inhibitors--magnesium, citrate, and pyrophosphate--suggest that these components contribute little to the ability to normal urine to inhibit the growth of calcium oxalate crystals. As yet unidentified urinary components seem to be responsible for most of this activity. The urinary crystal growth inhibitors appear to function by adsorbing on the surface of the growing crystals, thereby preventing the further incorporation of lattice ions. The fit of experimental data to the Langmuir absorption isotherm supports this conclusion.

Topics: Calcium; Chemical Phenomena; Chemistry, Physical; Citrates; Crystallization; Diphosphates; Humans; Ions; Magnesium; Oxalates; Urinary Calculi; Urine

Topics: Adult; Calcium; Depression, Chemical; Diphosphates; Humans; Middle Aged; Organophosphonates; Oxalates; Phosphates; Time Factors; Urinary Calculi

Topics: Adenoma; Adult; Diagnosis, Differential; Diphosphates; Female; Humans; Hyperparathyroidism; Male; Middle Aged; Parathyroid Neoplasms; Urinary Calculi

Topics: Acrylates; Azides; Benzoates; Calcium; Coloring Agents; Creatinine; Crystallization; Diphosphates; Glycolates; Hippurates; Humans; Metals; Oxalates; Phenylacetates; Urinary Calculi; Vitamins; Zinc

Topics: Diphosphates; Humans; Isoenzymes; Kidney; Phosphates; Phosphorus Isotopes; Pyrophosphatases; Urinary Calculi

Topics: Animals; Calcium; Chlorides; Diphosphates; Female; Food Additives; Magnesium; Methylene Blue; Phosphates; Rats; Sodium; Sulfates; Urinary Calculi

Topics: Acrylates; Aluminum; Chelating Agents; Chemical Phenomena; Chemistry; Coloring Agents; Crystallization; Diphosphates; Magnesium Oxide; Oxalates; Pyridoxine; Surface-Active Agents; Urinary Calculi

Topics: Animals; Depression, Chemical; Diphosphates; Injections, Intravenous; Kidney; Male; Mice; Phosphates; Phosphorus Isotopes; Pyrophosphatases; Statistics as Topic; Urinary Calculi

Topics: Calcium; Crystallization; Diphosphates; Humans; Hydrogen-Ion Concentration; Magnesium; Metabolic Clearance Rate; Oxalates; Phosphates; Secondary Prevention; Uric Acid; Urinary Calculi

The urinary excretion of inorganic pyrophosphate was determined in nine normal subjects and also in eight patients with recurrent calcium-containing renal stones during varied levels of phosphate intake. The excretion of pyrophosphate and orthophosphate is virtually the same in the two groups at all levels of phosphate intake. It appears unlikely that a consistently reduced urinary excretion of pyrophosphate is a factor in the formation of urinary calculi. Pyrophosphate excretion rose and calcium excretion fell with increasing phosphate intake; this might be expected to have a beneficial effect in patients with recurrent calcium stones.

Topics: Adult; Aged; Calcium; Creatine; Diet; Diphosphates; Humans; Middle Aged; Urinary Calculi

Topics: Diphosphates; Humans; Phosphates; Quaternary Ammonium Compounds; Uric Acid; Urinary Calculi; X-Ray Diffraction

Topics: Adult; Aged; Calcium; Citrates; Diet Therapy; Diphosphates; Female; Humans; Magnesium; Male; Middle Aged; Phosphates; Pyruvates; Urinary Calculi

Topics: Diet; Diphosphates; Humans; Urinary Calculi

Topics: Calcium; Calcium Phosphates; Citrates; Diphosphates; Humans; Indicators and Reagents; Magnesium; Oxalates; Phosphates; Urinary Calculi

Topics: Chemical Precipitation; Crystallization; Diphosphates; Kidney Calculi; Kidney Tubules; Milk; Nephrocalcinosis; Pathology; Pharmacology; Phosphates; Polyphosphates; Rats; Research; Solubility; Toxicology; Urinary Calculi; Urolithiasis

Topics: Calcium Phosphates; Diphosphates; Humans; Oxalates; Urinary Calculi

Topics: Biomedical Research; Calcium; Diphosphates; Humans; Pharmacology; Phosphates; Preventive Medicine; Urinary Calculi; Urine; Urolithiasis

Topics: Diphosphates; Humans; Metabolism; Phosphates; Pyrophosphatases; Urinary Calculi; Urine; Urolithiasis

Topics: Administration, Oral; Biomedical Research; Diphosphates; Phosphates; Rats; Research; Urinary Calculi; Urine; Urolithiasis

Topics: Calcium; Crystallization; Diphosphates; Models, Theoretical; Oxalates; Urinary Calculi