Regulation of osteopontin expression in a rat model of urolithiasis

Chin Med J (Engl). 2001 Aug;114(8):829-32.


Objective: To investigate the relationship between the expression and regulation of osteopontin (OPN) and urolithiasis.

Methods: Normal and stone model rats were treated with 1,25-dihydroxyvitamin D3(D3), vitamin K, testosterone or estradiol for 7 days, and the expression of osteopontin and its mRNA were detected with immunohistochemistry and Northern blot, respectively. Crystals deposited in rat kidneys were observed with a polarization microscope. The concentrations of crystal components in rat urine were determined.

Results: The results showed that vitamin K, testosterone and estradiol up-regulated the expression of OPN mRNA and its protein, thus decreasing the precipitation of calcium oxalate in rat kidneys. D3 increased the concentration of calcium in urine, and accelerated the sedimentation of calcium oxalate in rat kidneys.

Conclusions: These findings indicate that OPN may be an important macromolecule in the normal endogenous inhibition of the formation of urolithiasis. Vitamin K, testosterone and estradiol inhibit the formation of stones via up-regulating the expression of OPN in kidneys, while D3 over dose may accelerate the process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Kidney / metabolism
  • Male
  • Osteopontin
  • RNA, Messenger / analysis
  • Rats
  • Rats, Sprague-Dawley
  • Sialoglycoproteins / biosynthesis*
  • Sialoglycoproteins / physiology*
  • Urinary Calculi / metabolism*


  • RNA, Messenger
  • Sialoglycoproteins
  • Spp1 protein, rat
  • Osteopontin