1,25-Dihydroxyvitamin D3 and human bone-derived cells in vitro: effects on alkaline phosphatase, type I collagen and proliferation

Endocrinology. 1986 Oct;119(4):1776-85. doi: 10.1210/endo-119-4-1776.


1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3], but not 24,25-(OH)2D3 stimulates the alkaline phosphatase activity of cultured human bone cell populations. The stimulatory effect of the sterol was dose dependent (10(-10)-10(-7) M), evident by 24 h, and observed over a range of cell densities. Analysis of the radiolabeled collagens synthesised by human bone cell cultures indicated the synthesis of predominantly type I collagen. In the presence of 1,25-(OH)2D3, but not 24,25-(OH)2D3, there was a dose-dependent (10(-11)-10(-9) M) increase in radiolabeled proline incorporation into collagenase-digestible protein and in the amount of collagen synthesized, expressed as a percentage of the total protein synthesis. The effect of 1,25-(OH)2D3 was observed over a range of cell densities and appeared to be specific for the synthesis of type I collagen. The stimulatory effect of 1,25-(OH)2D3 on alkaline phosphatase activity and the increase in proline incorporation into collagenase-digestible protein were accompanied by a dose-dependent (5 X 10(-11) to 5 X 10(-8) M) inhibition of bone cell proliferation. These findings suggest that 1,25-(OH)2D3 is an important modulator of the growth and differentiation of human bone cells in vitro. They are also consistent with the possibility that 1,25-(OH)2D3 has direct effects on bone formation in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 24,25-Dihydroxyvitamin D 3
  • Alkaline Phosphatase / metabolism*
  • Bone and Bones / cytology
  • Bone and Bones / drug effects
  • Bone and Bones / metabolism*
  • Calcitriol / pharmacology*
  • Cell Division / drug effects
  • Cells, Cultured
  • Collagen / biosynthesis*
  • Dihydroxycholecalciferols / pharmacology
  • Dose-Response Relationship, Drug
  • Humans


  • Dihydroxycholecalciferols
  • 24,25-Dihydroxyvitamin D 3
  • Collagen
  • Alkaline Phosphatase
  • Calcitriol