Abnormal regulation of renal 25-hydroxyvitamin D-1 alpha-hydroxylase activity in the X-linked hypophosphatemic mouse.

Journal Article (Journal Article)

Abnormal vitamin D metabolism has been suspected in patients with X-linked hypophosphatemic rickets (XLH) and X-linked hypophosphatemic mice (Hyp-mice), the murine homologue of the human disease. We compared 25(OH)D-1 alpha-hydroxylase activity in the Hyp-mouse kidney to that in normal and phosphate-depleted mouse kidney. Weanling normal and Hyp-mice were fed a 0.6% phosphorus diet; phosphate-depleted mice received a 0.02% phosphorus diet. At 8-10 wk of age the serum phosphorus values in Hyp (3.35 +/- 0.12 mg/dl) and phosphate-depleted mice (3.83 +/- 0.56) were not significantly different. Despite the similar magnitude of phosphate depletion, however, the maximum levels of 25(OH)D-1 alpha-hydroxylase activity were disparate: phosphate-depleted mouse kidney had profoundly increased activity compared to normal (17.04 +/- .104 vs. 4.96 +/- 0.23 fmol 1,25(OH)2D3 produced/mg kidney per min) while Hyp-mouse kidney had a fourfold lesser increment (8.18 +/- 0.62). These data indicate that phosphate depletion is a potent stimulus of 25(OH)D-1 alpha-hydroxylase activity in the (C57BL6J) mouse. Moreover, the results show that abnormal regulation of 25(OH)D-1 alpha-hydroxylase activity is manifest in the Hyp-mouse.

Full Text

Duke Authors

Cited Authors

  • Lobaugh, B; Drezner, MK

Published Date

  • February 1, 1983

Published In

Volume / Issue

  • 71 / 2

Start / End Page

  • 400 - 403

PubMed ID

  • 6681616

Pubmed Central ID

  • PMC436881

International Standard Serial Number (ISSN)

  • 0021-9738

Digital Object Identifier (DOI)

  • 10.1172/jci110783


  • eng

Conference Location

  • United States