Effects of low phosphate intake on bone and mineral metabolism in rats: evaluation by biochemical markers and pyridinium cross-link formation in bone.
We have investigated the changes in biochemical markers and in pyridinium cross-links in bone in hypophosphatemic rats. Six-week-old female Wistar rats were divided into two groups (normal diet and a phosphate-deficient diet) and fed for 8 weeks. A low phosphate intake caused a significant difference in the concentrations of osteocalcin and alkaline phosphatase with advancing rachitis as well as an increase in bone resorption marker concentrations in urine. Femur biochemical analysis revealed a significant (p < 0.005) increase in deoxypyridinoline per mole collagen in the phosphate-deficient group which suggested that urinary excretions of pyridinium cross-links might reflect not only bone resorption but also increased pyridinium cross-links in bone matrix collagen. Our results demonstrate that a low phosphate intake causes an increase of pyridinium cross-link formation as well as a discrepancy between the circulation levels of alkaline phosphatase and osteocalcin with advancing rachitis. These alterations induced by low phosphate intake should be considered when interpreting the values of biochemical markers.
Hoshino
H
H
Department of Orthopedic Surgery, Hamamatsu University School of Medicine, Japan.
Kushida
K
K
Takahashi
M
M
Koyama
S
S
Yamauchi
H
H
Inoue
T
T
D000469:Alkaline Phosphatase / Q000097:blood / Q000187:drug effects; D000596:Amino Acids / Q000652:urine; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D001842:Bone and Bones / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism; D003720:Densitometry; D004032:Diet; D002149:Energy Intake; D005260:Female; D005269:Femur / Q000737:chemistry / Q000187:drug effects; D015675:Osteocalcin / Q000097:blood / Q000187:drug effects; D010710:Phosphates / Q000008:administration & dosage* / Q000097:blood; D011726:Pyridinium Compounds / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain / Q000187:drug effects
D000596:Amino Acids; D015415:Biomarkers; D003432:Cross-Linking Reagents; D010710:Phosphates; D011726:Pyridinium Compounds; D015675:Osteocalcin; C015484:pyridinoline; C036020:deoxypyridinoline; D000469:Alkaline Phosphatase