1α，25双羟维生素D3对成骨样细胞增殖与分化的影响

采用同位素掺入，细胞周期、细胞化学和扫描电镜等方法观察了１α，２５双羟维生素Ｄ３［１，２５（ＯＨ）２Ｄ３］对人及大鼠成骨样细胞ＯＳ－７３２和ＲＯＳ１７／２．８增殖及分化的影响。结果表明：１，２５（ＯＨ）２Ｄ３对ＯＳ－７３２细胞增殖的抑制作用呈明显的时效和量效关系。在给１０－７ｍｏｌ／Ｌ的１，２５（ＯＨ）２Ｄ３后第４和第６天，对ＯＳ－７３２细胞生长的抑制率分别为４０％和６０％；对ＤＮＡ，ＲＮＡ和蛋白质合成的抑制作用分别为５９％，４１％和２２％。流式细胞计测定结果表明：１，２５（ＯＨ）２Ｄ３使ＤＮＡ合成受阻；扫描电镜显示：１，２５（ＯＨ）２Ｄ３有抑制ＲＯＳ１７／２．８细胞表面微绒毛的作用。此外，细胞化学染色表明：该激素有增加成骨样细胞碱性磷酸酶活性和促进骨形态形成蛋白合成的作用，即刺激骨形成的作用。

Effect of 1, 25-dihydroxyvitamin D3 on proliferation and differentiation in osteoblast-like cells

The ability of hormonally active 1, 25-dihydroxyvitamin D3[1, 25 (OH)23] to affect cell growth and differentiation was observed in human osteoblast-like cell line OS-732 and rat ROS 17/2. 8 cells. It was found that inhibition was specific for 1, 25(OH)2D3 in dose and time dependent manner and the inhibition rate reached 40% and 60% after 4 and 6 day exposure to 10-7mol/L 1,25(OH)2D3. The biosynthesis rates of DNA,RNA and protein decreased by 59%, 40% and 22% respectively on day 4 after 10-7mol/L 1, 25 (OH)2D3 treatment. The histogram of DNA synthetic phase by flow cytometry demonstrated that the DNA synthetic phase decreased after 1, 25 (OH)2D3 treatment. The decrease of microvillus. on surface of ROS 17/2. 8 cells after 1, 25 (OH)2D3 treatment was observed by scanning electron microscopy. In addition, hormone treatment on day 4 caused an increase of cellular alkaline phosphate activity and bone morphogenic protein synthesis by histochemical staining in osteoblast-like cells. It shows that 1, 25 (OH)2D3 stimulates bone formation.