磷对体外大鼠成骨细胞增殖分化及钙化功能的影响

在体外培养大鼠成骨细胞的过程中添加磷(0、1、2、4 mmol/L),检测不同时间内的细胞增殖能力、碱性磷酸酶活性、骨桥蛋白表达及钙化功能,探讨了磷对成骨细胞增殖分化及钙化的影响。结果表明,磷能促进成骨细胞增殖,随着磷浓度的增加,增殖作用减弱,只在添加磷后第6、7 d极显著高于对照组;磷能显著或极显著地抑制碱性磷酸酶活性,即作用第5 d时,4 mmol/L磷组显著低于1 mmol/L磷组;作用第8 d时,4 mmol/L磷组显著低于1 mmol/L磷组,2 mmol/L磷组极显著低于4 mmol/L磷组;磷能诱导骨桥蛋白的表达(P<0.01),12、mmol/L高于4 mmol/L磷组;磷能诱导钙化,钙化结节个数极显著高于对照组,钙化结节平均面积只有1 mmol/L磷组显著高于对照组,随着磷浓度的变大,钙化结节平均面积逐渐减小而钙化结节个数则逐渐增多。表明添加不同浓度的磷均能抑制成骨细胞的早期分化,促进其增殖,诱导细胞基质成熟及钙化,利于新骨的形成,但4 mmol/L磷组效果较差。

Effects of phosphate on proliferation, differentiation and calcification of osteoblasts of rat in vitro

Osteoblasts were exposed to phosphate(0,1,2 and 4 mmol/L) in vitro to examine the proli-feration of the osteoblasts,the activity of alkaline phosphatase(AKP) and the expression and calcification of osteopontin in the osteoblasts and to elucidate the influence of phosphate on proliferation,differentiation and calcification of the osteoblasts in vitro.The proliferation of osteoblasts was enhanced very significantly by phosphate only on 6th d and 7th d post-exposure.The activity of AKP was inhibited significantly by phosphate,i.e.the activity of AKP was inhibited significantly in the 4 mmol/L-phosphate group as compared with those in the 1 mmol/L on 5th d,and inhibited significantly in 4 mmol/L as compared with those in the 1 mmol/L and in the 2 mmol/L as compared with those in the 4 mmol/L on 8th d.The expression of osteopontin was induced very significantly,and the expression was higher in the 1 mmol/L-and the 2 mmol/L-phosphate groups than in the 4 mmol/L-phosphate group.Compared with those of control group,the counts of calcified nodules(P<0.01),and the average size of the calcified nodules in the 1 mmol/L-phosphate group(P<0.05) were significantly higher.Along with increase of concentration of phosphate,the average size of the calcified nodules was decreased gradually and the counts of calcified nodules was increased gradually.In conclusion,phosphate could inhibit early differentiation of osteoblasts,promote proliferation of osteoblasts,induce matrix maturation and calcification,and be beneficial to formation of new bones.