钙缺乏对大鼠骨骼发育的影响及其机制探讨

在建立钙缺乏动物模型的基础上 ,利用骨形态计量学方法观察缺钙对生长期大鼠骨骼发育的影响 ,并通过测定血清有关激素的变化探讨其机制。组织形态学显示缺钙大鼠骨形成量减少 ,矿化能力降低 ,空间结构破坏 ;同时钙缺乏大鼠骨矿物质含量和骨密度均显著降低 ,血清甲状旁腺激素水平明显增高 ,降钙素水平显著降低 ;骨组织羟脯氨酸含量降低。提示钙缺乏通过影响骨骼矿物质含量、激素分泌以及有机质形成 ,使骨形态结构发生异常改变 ,最终导致骨骼发育障碍

Effects of dietary calcium-deficiency on bone development in growing rats and the mechanism involved

The effects of calcium on bone development in growing rats were studied by bone histomorphometry and the hormone changes in a model of calcium|deficient rats. Thirty growing Wistar rats were randomly allocated into three groups fed with low calcium diet, calcium|sufficient diet at libitum or pair fed with low calcium diet for 8 weeks. The calcium|deficient rats showed low bone mass, significantly decreased bone density and mineral content. The disorder of bone molding and ultrastructure at the femoral distal diaphysis of the calcium deficient rats were showed by histomorphometric parameters. The concentration of serum parathyroid hormone was significantly higher, calcitonin was significantly lower, and the content of hydroxyproline in bone was significantly lower. The results indicated that dietary calcium|deficiency might stimulate the secretion of parathyroid hormone, decrease bone mineral content and inhibit the synthesis of bone matrix, which might induce a defect on bone mineralization.