title: Effect of high phosphorus diet on phosphorus metabolism in parathyroidectomized rats.
abstract: To determine the parathyroid hormone (PTH) action on kidney and bone by high phosphorus (P) diet, this study investigated PTH/PTH-related peptide (PTHrP) receptor mRNA expression in 6-week-old parathyroidectomized (PTX) rats received constant amount of PTH. To maintain serum PTH levels equally to sham operated rats, PTX rats were constantly exposed to rPTH (1-34) and fed a control diet (0.3% P) and a high P diet (1.2% P) for 7 days, respectively. There were no significant differences in serum PTH (1-34) concentration in rats fed the control diet. In sham groups, serum PTH concentrations, both (1-84) and (1-34) fragments, were increased in rats fed the high P diet than in rats fed the control diet. Urinary excretions of P and C-terminal telopeptides of type I collagen were significantly increased in both PTX and sham rats by the high P diet. PTH/PTHrP receptor mRNA expression in kidney and femur was not changed in both PTX and sham rats by the high P diet. In conclusion, high P diet did not change PTH action in PTX rats and increased urinary excretion of P and bone resorption regardless of PTH action.
authors.affiliation: Department of Nutritional Science, Faculty of Applied Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Katsumata
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Masuyama
authors.forename: Moyuru
authors.initials: M
authors.lastname: Koshihara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsuzaki
authors.forename: Mariko
authors.initials: M
authors.lastname: Uehara
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood; D004032:Diet; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000097:blood; D016105:Parathyroidectomy; D010758:Phosphorus / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D010281:Parathyroid Hormone; D012333:RNA, Messenger; D044168:Receptor, Parathyroid Hormone, Type 1; D010758:Phosphorus; D002118:Calcium