silicon and Urinary-Calculi

Topics: Animals; Chick Embryo; Fluorides; Humans; Rats; Silicon; Urinary Calculi

Two 8-wk experiments were conducted with Sprague-Dawley weanling rats to determine whether interactions occurring between Zn and Si, or a nutritional deficiency of either Cu or Zn, affect silica urolith formation. In Exp. 1, concentrations of 0, 540, and 2,700 mg of Si/kg of diet from tetraethylorthosilicate were used with dietary Zn concentrations of 4, 12, and 500 mg/kg of diet in a 3 x 3 factorial arrangement. In Exp. 2, copper at 1 or 5 mg/kg of diet and Zn at 4, 12, and 500 mg/kg of diet were used in a 2 x 3 factorial arrangement. All diets in Exp. 2 contained 2,700 mg of Si/kg. Silica uroliths occurred in all treatments providing, 2,700 mg of Si/kg of diet. There was a trend (P = .17) toward a reduction of silica urolith incidence with increasing concentrations of dietary Zn in Exp. 1. In Exp. 2, a deficiency of Zn, and a Cu deficiency exacerbated by 500 mg of Zn/kg of diet, increased (P < .05) silica urolith formation. An antagonism between Si and Zn, as demonstrated previously in the rat, may not be of a sufficient magnitude to be applicable to the prevention of silica urolithiasis. The data further demonstrate that Zn deficiency and, to a lesser extent, Cu deficiency contributed to silica urolith formation in rats fed diets having a high content of absorbable Si. However, 540 mg of Si/kg of diet may potentiate the metabolic activity of Zn, as indicated by a 23% Si-mediated weight gain response in Zn-deficient rats.

Topics: Alkaline Phosphatase; Animals; Body Weight; Calcium; Copper; Disease Models, Animal; Magnesium; Male; Phosphorus; Rats; Rats, Sprague-Dawley; Silicon; Silicon Dioxide; Urinary Calculi; Zinc

Topics: Adult; Antacids; Female; Humans; Magnesium; Magnesium Silicates; Silicic Acid; Silicon; Urinary Calculi

Three experiments were conducted to determine the effects of excess dietary calcium carbonate, phosphorus and urine acidifying and alkalizing salts on silica urolith formation in a model using rats fed dextrose-based diets containing 2% tetraethylorthosilicate (TES). Diets containing 2% TES lowered weight gains to 91-95% of gains made by rats fed non-TES diets. Urine silica concentrations of rats fed TES were generally in the range of 50-60 mg/dl. In experiment 1, rats fed TES with no additional dietary calcium carbonate had a silica urolith incidence of 35%. With additions of 1 and 2% calcium carbonate to the basal-TES diet, respective urolith incidences were 45 and 60% (r = 0.99, P less than 0.02). In experiment 2, monobasic sodium phosphate (MP) providing 0.2% additional phosphorus resulted in a mean urine pH of 6.42 and no uroliths. Dibasic sodium phosphate (DP) without and with 0.5% sodium bicarbonate (SB) resulted in respective urine pH values of 6.78 and 7.14 and urolith incidences of 15 and 20% (MP less than DP and DP + SB, P less than 0.05). However, the uroliths were small averaging less than 1 mg. In experiment 3, substitution of autoclaved egg albumin for casein, the protein source in experiments 1 and 2, resulted in urine pH of 7.45 and a silica urolith incidence of 46%. An equal-molar mixture of MP and DP providing an added 0.2% phosphorus resulted in a urine pH of 7.07 and reduced the urolith incidence to 4%, and 0.75% of dietary ammonium chloride either with or without the added 0.2% phosphorus gave urine acidification and complete protection from uroliths.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Administration, Oral; Animals; Bicarbonates; Body Weight; Calcium; Calcium Carbonate; Carbonates; Diet; Drug Interactions; Hydrogen-Ion Concentration; Magnesium; Male; Phosphorus; Rats; Rats, Inbred Strains; Silanes; Silicon; Silicon Dioxide; Sodium; Sodium Bicarbonate; Urinary Calculi

Rats fed a dextrose-casein type of diet adequate for normal growth and containing 2% of tetraethylorthosilicate (TES) were used to study the effect of NaCl and Na2SO4 drinking waters, and dietary additions of chloride, sulfate and phosphate on formation of silica urinary calculi. In experiment 1, rats fed the basal-TES diet had a 53% incidence of silica urinary calculi. NaCl or Na2SO4 (0.07 N) drinking waters each increased (P less than 0.01) water intake and urine volume, whereas only NaCl reduced (P less than 0.05) the incidence of silica urinary calculi. The incidence of calculi in the rats treated with NaCl and Na2SO4 was 15 and 55%, respectively. The saline waters had similar effects on urine pH, silica, phosphorus, magnesium and calcium, as well as blood plasma magnesium and calcium. Plasma phosphorus tended to be higher (P = 0.08) in the NaCl-treated rats. In experiment 2, 50% of rats fed the basal-TES diet developed silica urinary calculi. Addition of 0.2 eq/kg diet of chloride, sulfate or phosphate as sodium salts (phosphate was an equal molar mixture of mono- and dibasic sodium phosphates) resulted in a reduction in silica urinary calculi (P less than 0.05) by dietary chloride (15% incidence) and phosphate (5% incidence) but not by sulfate (35% incidence). Water intake and urine volumes did not differ, urine calcium was increased (P less than 0.05) by sulfate, and urine phosphorus was increased (P less than 0.05) by phosphate. Blood plasma concentrations of calcium and magnesium did not differ, but plasma phosphorus was higher for animals fed the additional phosphate (P less than 0.1) or chloride (P less than 0.05) in the 2% TES diet.

Topics: Administration, Oral; Animals; Chlorides; Kidney; Male; Phosphates; Rats; Rats, Inbred Strains; Silanes; Silicon; Sulfates; Urinary Calculi; Water

An in vitro mineralizing system using bovine achilles tendon developed by Thomas and Tomita (3) was modified to enable quantitative evaluation of mineralization. Using this modified method, the potential effect of various ions on the rate of calcium uptake from inorganic mineralization medium was measured. Of the elements tested, only silicon and fluoride accelerated calcium uptake, whereas magnesium had an inhibitory effect. The simultaneous presence of silicon and fluoride in the medium had a synergistic action on calcium uptake. Urine of stone formers showed high propensity to mineralize tendon collagen, but not the urine of non-stone formers. Total content, and concentration of silicon in urine of stone formers was significantly higher than in normal urine. Addition of silicon to non-stone formers urine enhanced its capacity to mineralize collagen in vitro. These results strongly suggest the possible involvement of silicon and fluoride in the genesis of urinary calculi in man.

Topics: Achilles Tendon; Adult; Animals; Calcium; Cattle; Collagen; Fluorides; Humans; In Vitro Techniques; Magnesium; Male; Middle Aged; Minerals; Silicon; Urinary Calculi

Topics: Female; Humans; Kidney Calculi; Male; Silicon; Ureteral Calculi; Urethral Diseases; Urinary Bladder Calculi; Urinary Calculi

Topics: Animals; Cattle; Proteins; Silicon; Urinary Calculi; Urolithiasis