title: Effects of a high-calcium diet on serum insulin-like growth factor-1 levels in magnesium-deficient rats.
abstract: In order to clarify the effects of a high-calcium (Ca) diet on bone formation in magnesium (Mg)-deficient rats, this study focused on the effects of a high-Ca diet on serum insulin-like growth factor-1 (IGF-1) levels. Male rats were randomized by weight into four groups, and fed one of four experimental diets containing two different Mg concentrations (0.05% (normal-Mg) or Mg-free (Mg-deficient)), and two different Ca concentrations (0.5% (normal-Ca) or 1.0% (high-Ca)) for 14 days. Serum concentrations of osteocalcin and IGF-1 were significantly lower in rats fed the Mg-deficient diet than in rats fed the normal-Mg diet. On the other hand, dietary Ca concentration had no significant influence on serum concentrations of osteocalcin and IGF-1. This study suggested that: 1) a high-Ca diet has no preventive effects on the decreased bone formation seen in Mg-deficient rats; and 2) a high-Ca diet does not enhance serum IGF-1 levels in Mg-deficient rats. Moreover, unchanged serum IGF-1 concentrations may contribute to the decreased bone formation seen in Mg-deficient rats receiving a high-Ca diet.
authors.affiliation: Department of Nutrition, Junior College of Tokyo University of Agriculture, Tokyo, Japan. matsu@nodai.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kajita
authors.forename: Misao
authors.initials: M
authors.lastname: Miwa
mesh_terms: D000818:Animals; D002118:Calcium / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000494:pharmacology*; D004032:Diet; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000378:metabolism; D008274:Magnesium / Q000097:blood; D008275:Magnesium Deficiency / Q000097:blood* / Q000378:metabolism; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D007334:Insulin-Like Growth Factor I; D008274:Magnesium; D002118:Calcium