期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：17
页码：6522-6526
DOI：10.1073/pnas.87.17.6522
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The effects of vitamin D metabolites on alkaline phosphatase [ALPase; orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1 ] activity, a marker of terminal differentiation, in chondrocyte cultures and growth plates in vivo were examined. In cultures of pelleted rabbit growth-plate chondrocytes, 1,25-dihydroxycholecalciferol (1,25-dihydroxyvitamin D3) increased the contents of DNA and macromolecules containing uronic acid (proteoglycans). It also decreased ALPase activity with an ED50 of less than 1 nM. Other vitamin D3 metabolites, such as 24,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol, had little effect on these biochemical parameters. In rachitic growth plates, the uronic acid content was half that in normal growth plates, whereas ALPase activity was 2.5 times that in normal growth plates. Administration of 1,25-dihydroxycholecalciferol at a low dose (0.1 micrograms per kg of body weight) to rachitic rats increased the uronic acid content 1.4-fold and decreased ALPase activity by 40%. This compound, like 24,25-dihydroxycholecalciferol (10 micrograms per kg of body weight), increased the calcium level of the blood. However, administration of 24,25-dihydroxycholecalciferol had little effect on the uronic acid and ALPase contents in growth plates. These observations suggest that 1,25-dihydroxycholecalciferol is a bioactive form of vitamin D that plays an important role in the control of chondrocyte terminal differentiation.
