Adaptive responses of 25-hydroxyvitamin D31-alpha hydroxylase expression to dietary phosphate restriction in young and adult rats

Wan Ping Lai, Tsui Shan Chau, Pik Yuen Cheung, Wen Fang Chen, Chun Lap Samuel Lo, Murray J. Favus, Man Sau Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

6 Citations (Scopus)

Abstract

Regulation of vitamin D metabolism alters with age. The present study is undertaken to investigate if the loss of renal 1,25-dihydroxyvitamin D3(1,25(OH)2D3) production in response to dietary phosphate (P) restriction in adult rats is due to an alteration in the renal expression of 25-hydroxyvitamin D31-alpha hydroxylase (1-OHase). Young (4-6 weeks old) and adult (12-14 weeks old) male Sprague Dawley rats were fed either normal P (NPD) or low P diet (LPD) for 0-5 days. Basal expression of 1-OHase protein was higher in adult rats. Young rats, but not adult rats, significantly increased 1-OHase protein and mRNA expressions in response to LPD in a time-dependent manner. To determine if the stability of renal 1-OHase protein changes with LPD feeding, young and adult rats fed either NPD or LPD for 5 days were injected intravenously with cycloheximide (CHX), a protein synthesis inhibitor. CHX decreased 1-OHase protein expression in young rats fed NPD. However, CHX did not alter 1-OHase protein expression in young rats fed LPD nor in adult rats fed either diet. The results indicate that the stability of renal 1-OHase protein increased with age and that LPD increased its stability only in young rats.
Original languageEnglish
Pages (from-to)34-42
Number of pages9
JournalBiochimica et Biophysica Acta - Molecular Basis of Disease
Volume1639
Issue number1
DOIs
Publication statusPublished - 1 Sep 2003

Keywords

  • 25-Hydroxyvitamin D 1-alpha hydroxylase protein 3
  • Aging
  • CYP27B mRNA expression
  • Low phosphate diet (LPD)
  • Renal proximal tubule

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology

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