title: Onset of nephrocalcinosis depends on dietary phosphorus concentration in male rats fed a magnesium-deficient diet.
abstract: Although a magnesium (Mg)-deficient diet is generally known to induce nephrocalcinosis, our previous study observed that despite the administration of a Mg-deficient diet, the kidney calcium (Ca) and phosphorus (P) concentrations were not increased in male rats. We speculated that this result was due to the P concentration of the experimental diet based on the AIN-93G formula used in the previous study. In the present study, male rats were fed modified AIN-93G diets containing the two different Mg concentrations [0.5 g per kg diet (normal-Mg) or Mg-free (Mg-deficient)] and three different P concentrations [3 (3-P), 5 (5-P) or 7 (7-P) g per kg diet]. By histological examination of the kidney, nephrocalcinosis was not observed in rats fed on the Mg-deficient diet containing 3-P While nephrocalcinosis appeared in rats fed on the Mg-deficient diet containing 5-P and 7-P The degree of nephrocalcinosis was severe in rats fed on the Mg-deficient diet containing 7-P compared with rats fed on the Mg-deficient diet containing 5-P These results demonstrated that the Mg-deficient diet based on AIN-93G formula dose not induce nephrocalcinosis and that the Mg-deficient diet based on AIN-93G formula with increased dietary P concentrations induces nephrocalcinosis in male rats. We suggest that the onset of nephrocalcinosis could depend on the dietary P concentration in male rats fed on a Mg-deficient diet.
authors.affiliation: Department of Nutrition, Junior College of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan. matsu@nodai.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: S
authors.initials: S
authors.lastname: Katsumata
authors.forename: M
authors.initials: M
authors.lastname: Uehara
authors.forename: M
authors.initials: M
authors.lastname: Miwa
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000821:Animal Feed; D000818:Animals; D002118:Calcium / Q000378:metabolism; D004032:Diet / Q000009:adverse effects; D007668:Kidney / Q000378:metabolism; D008274:Magnesium / Q000097:blood; D008275:Magnesium Deficiency / Q000150:complications* / Q000378:metabolism; D008297:Male; D009397:Nephrocalcinosis / Q000209:etiology* / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D016226:Phosphorus, Dietary / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016226:Phosphorus, Dietary; D010758:Phosphorus; D008274:Magnesium; D002118:Calcium