Silicon-zinc interactions and potential roles for dietary zinc and copper in minimizing silica urolithiasis in rats.
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.
Olson Biochemistry Laboratories, South Dakota State University, Brookings 57007.
S R
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Stewart
R J
RJ
Emerick
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Kayongo-Male
D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001835:Body Weight; D002118:Calcium / Q000097:blood / Q000652:urine; D003300:Copper / Q000008:administration & dosage* / Q000097:blood / Q000172:deficiency / Q000378:metabolism; D004195:Disease Models, Animal; D008274:Magnesium / Q000097:blood / Q000652:urine; D008297:Male; D010758:Phosphorus / Q000097:blood / Q000652:urine; D051381:Rats; D017207:Rats, Sprague-Dawley; D012825:Silicon / Q000008:administration & dosage* / Q000378:metabolism; D012822:Silicon Dioxide / Q000032:analysis; D014545:Urinary Calculi / Q000737:chemistry / Q000209:etiology / Q000517:prevention & control / Q000662:veterinary*; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood / Q000172:deficiency / Q000378:metabolism
D010758:Phosphorus; D012822:Silicon Dioxide; D003300:Copper; D000469:Alkaline Phosphatase; D008274:Magnesium; D015032:Zinc; D002118:Calcium; D012825:Silicon