Effects of Vitamin D Metabolites on Mineralization of Embryomic Chick Femurs In Vitro.

Abstract

We examined the effects of vitamin D metabolites on mineralization of the 10-day embryonic chick femurs in organ culture system. When 5-day cultures kept in the control medium were cultured in the several mediums containing 1α (OH) D3, 1, 25 (OH) 2D3 or 24, 25 (OH) 2D3 at concentration of 10-11-10-8 M during an additional 5 days, the mineralization of cultured bones increased in the treatment with 1α (OH) D3 at concentration of 10-10-10-8M, and decreased in the treatment with 1, 25 (OH) 2D3 at concentration of 10-10-10-8 M, and was no change in the treatment with 24, 25 (OH) 2D3. The activities of both alkaline phosphatase and acid phosphatase did not change in the cultured bones with vitamin D metabolites. These results suggested that 1α (OH) D3 increased bone formation, 1, 25 (OH) 2D3 stimulated bone resorption, and 24, 25 (OH) 2D3 had no effect to bone-remodeling in this organ culture system.