Skip to main content
construction release_alert
Scholars@Duke will be undergoing maintenance April 11-15. Some features may be unavailable during this time.
cancel

Calcitonin stimulation of renal 25-hydroxyvitamin D-1 alpha-hydroxylase activity in hypophosphatemic mice. Evidence that the regulation of calcitriol production is not universally abnormal in X-linked hypophosphatemia.

Publication ,  Journal Article
Nesbitt, T; Lobaugh, B; Drezner, MK
Published in: J Clin Invest
January 1987

Hypophosphatemia (Hyp) mice have defective regulation of 25(OH)D-1 alpha-hydroxylase activity in response to hypophosphatemia, hypocalcemia, and parathyroid hormone (PTH) administration. However, recent observations support the existence of anatomically distinct, independently regulated renal 1 alpha-hydroxylase systems in mammalian proximal convoluted and straight tubules. To more completely define the extent of the 1 alpha-hydroxylase regulatory defect in Hyp-mice, we compared enzyme maximum velocity in normal and mutants after infusion of calcitonin. Upon stimulation, renal 1 alpha-hydroxylase activity increased to similar levels in normal and Hyp-mouse renal homogenates. Moreover, time-course and dose-dependence studies revealed similar patterns of response in the animal models. Subsequently, we examined whether PTH and calcitonin stimulatory effects on enzyme activity are mediated through different mechanisms. In both animal models administration of PTH and calcitonin increased enzyme activity to levels greater than those obtained after maximal stimulation by either hormone alone, consistent with additive effects. These observations indicate that a calcitonin-sensitive component of 1 alpha-hydroxylase is not compromised in the X-linked hypophosphatemic syndrome.

Duke Scholars

Published In

J Clin Invest

DOI

ISSN

0021-9738

Publication Date

January 1987

Volume

79

Issue

1

Start / End Page

15 / 19

Location

United States

Related Subject Headings

  • X Chromosome
  • Steroid Hydroxylases
  • Parathyroid Hormone
  • Mice
  • Kidney
  • Immunology
  • Hypophosphatemia, Familial
  • Enzyme Activation
  • Calcitriol
  • Calcitonin
 

Citation

APA
Chicago
ICMJE
MLA
NLM

Published In

J Clin Invest

DOI

ISSN

0021-9738

Publication Date

January 1987

Volume

79

Issue

1

Start / End Page

15 / 19

Location

United States

Related Subject Headings

  • X Chromosome
  • Steroid Hydroxylases
  • Parathyroid Hormone
  • Mice
  • Kidney
  • Immunology
  • Hypophosphatemia, Familial
  • Enzyme Activation
  • Calcitriol
  • Calcitonin