锌对骨发育影响的体外研究

目的　研究锌对骨发育的影响。方法　将 1 6 d孕龄的小鼠 (每组 1 2只 )脱颈椎处死 ,无菌条件下切下胎鼠的前肢分 5组 ,分别在基础培养基 (Zn2 + 浓度为 2 0 μmol/L)及基础培养基中加终浓度为 2 0 μmol/L的 Zn2 +络合剂 (TPEN) ,及基础培养基中加 Zn SO4 至 Zn2 +浓度分别为45 μmol/L、70 μmol/L、1 2 0 μmol/L的培养基中培养 6 d。结果　 1 .培养后的胎鼠右肢与未培养左肢相比 ,其长骨长度、骨组织密度均有所增加 ;组织学分析显示 :骨组织呈活跃增殖分化相 ,骨小梁增加 ,骨基质深染。2 .生化指标及 4 5Ca示踪显示 :培养基中缺锌和在培养基中补充 Zn2 + 至 Zn2 + 浓度1 2 0μmol/L时 ,骨组织中骨钙素 (OC)和 4 5Ca含量减少 ,碱性磷酸酶 (AKP)活性降低 (P<0 .0 5 ) ;当在培养基中补充 Zn2 + 至 Zn2 + 浓度 45μmol/L、70μmol/L时 OC合成量 ,骨组织对钙的吸收及AKP活性增加 (P<0 .0 5 )。 3 .形态学指标 :X- ray显示 ,培养液中缺锌和锌浓度为 1 2 0 μmol/L时 ,长骨长度和密度与对照组相比 ,长骨长度较短 ,骨密度降低 ;当在培养液中 Zn2 +浓度分别为 45μmol/L和 70 μmol/L时 ,与对照组相比 ,长骨长度及其骨密度有所增加。结论　锌参与骨组织发育的生理和生化过程 ,锌缺乏 /过量时均可影响骨的正常

IN VITRO STUDY ON EFFECTS OF ZINC ON BONE DEVELOPMENT

Objective: To explore the effects of zinc on bone development in vitro. Methods: Mice of 16 gestation were killed by snapping cervical vertebra, and the front limbs were cut off and cultured in basic medium. Which contained 20 μmol/L Zn 2+ (control group). In Zn deprived group, the basic medium was added TPEN to final concentration 20 μmol/L. In other three groups, the basic medium was added ZnSO 4 to final concentration of Zn 2+ at 45, 70, and 120 μmol/L respectively. Results: 1. Compared with control limb(uncultivated),the test limb(cultivated for 6 d)showed longer bone length and higher bone density.Histological analysis showed active bone cell differentiation, proliferation, increased bone trabecula.2.Compared with control group, the Zn-deprived and Zn 2+ 120 μmol/L group expressed decreased osteocalcin (OC) and 45 Ca content and lower activity of AKP; Zn 2+ 45 μmol/L and 70 μmol/L group presented increased OC and 45 Ca content and higher activity of AKP.3.Compared with the control group, Zn-deprived and Zn 2+ 120μmol/L group showed shorter bone length and lower bone density; Zn 2+ 45 μmol/L and 70μmol/L group showed longer bone length and higher bone density. Conclusion: Zinc is involved in bone metabolism and growth; both zinc-deficiency and zinc-excess can alter bone growth and normal metabolism.